imaging-flow-cytometry-based-analysis-cell-position-cell-cycle-3d

Imaging- and Flow Cytometry-based Analysis of Cell Position and the Cell Cycle in 3D Melanoma Spheroids

Three-dimensional (3D) tumor spheroids are utilized in cancer research as a more accurate model of the in vivo tumor microenvironment, compared to ...

The Centenary Institute

University of Sydney

The human melanocortin-1 receptor gene (MC1R) encodes a G-protein coupled receptor that is primarily expressed on melanocytes, where it plays a key role in pigmentation regulation. Variant alleles are associated with red hair colour and fair skin, known as the RHC phenotype, as well as skin cancer risk. The R151C, R160W and D294H alleles, designated 'R', are strongly associated with the RHC phenotype and have been proposed to result in loss of function receptors due to impaired G-protein coupling. We recently provided evidence that the R151C and R160W variants can efficiently couple to G-proteins in response to alpha-melanocyte stimulating hormone. The possibility that altered cellular localization of the R151C and R160W variant receptors could underlie their association with RHC was therefore considered. Using immunofluorescence and ligand binding studies, we found that melanocytic cells exogenously or endogenously expressing MC1R show strong surface localization of the wild-type and D294H alleles but markedly reduced cell surface expression of the R151C and R160W receptors. In additional exogenous expression studies, the R variant D84E and the rare I155T variant, also demonstrated a significant reduction in plasma membrane receptor numbers. The V60L, V92M and R163Q weakly associated RHC alleles, designated 'r', were expressed with normal or intermediate cell surface receptor levels. These results indicate that reduced receptor coupling activity may not be the only contributing factor to the genetic association between the MC1R variants and the RHC phenotype, with MC1R polymorphisms now linked to a change in receptor localization.

Altered cell surface expression of human MC1R variant receptor alleles associated with red hair and skin cancer risk.

To address the issue of melanocortin-1 receptor (MC1R) expression in non-melanocytic cells, we have quantitatively evaluated the relative expression levels of both MC1R mRNA and protein in a subset of different cell types. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) at high cycle numbers, we detected MC1R mRNA in all cell types examined, including human embryonic kidney-293 (HEK 293) cells, a cell type widely used as a negative control in melanocortin expression studies. Quantitative real-time PCR revealed the highest levels of MC1R transcripts were in melanocytic cells, whereas the keratinocyte and fibroblast cell cultures examined had only a low level of expression, similar to that of HEK 293 cells. Antibody mediated detection of MC1R protein in membrane extracts demonstrated exogenous receptor in MC1R transfected cell lines, as well as endogenous MC1R in melanoma cells. However, radioligand binding procedures were required to detect MC1R protein of normal human melanocytes and no surface expression of MC1R was detected in any of the non-melanocytic cells examined. This was consistent with their low level of mRNA, and suggests that, if present, the levels of surface receptor are significantly lower than that in melanocytes. The capacity of such limited levels of MC1R protein to influence non-melanocytic skin cell biology would likely be severely compromised. Indeed, the MC1R agonist [NIe(4), D-Phe(7)] alpha-melanocyte stimulating hormone (NDP-MSH) was unable to elevate intracellular cyclic adenosine monophosphate (cAMP) levels in the keratinocyte and fibroblast cells examined, whereas a robust increase was elicited in melanocytes. Although there are a variety of cell types with detectable MC1R mRNA, the expression of physiologically significant levels of the receptor may be more restricted than the current literature indicates, and within epidermal tissue may be limited to the melanocyte.

Quantitative analysis of MC1R gene expression in human skin cell cultures.

The human melanocortin-1 receptor (MC1R) is a G-protein coupled receptor involved in the regulation of pigmentation. Several MC1R variant alleles are associated with red hair, fair skin and increased skin cancer risk. We have performed a systematic functional analysis of nine common MC1R variants and correlated these results with the strength of the genetic association of each variant allele with pigmentation phenotypes. In vitro expression studies revealed that variant receptors with reduced cell surface expression, including V60L, D84E, R151C, I155T, R160W and R163Q, showed a corresponding impairment in cAMP coupling. The R142H and D294H variants demonstrated normal cell surface expression, but had reduced functional responses, indicating that altered G-protein coupling may be responsible for this loss of function. The V92M variant cAMP activation was equal to or higher than that for wild-type MC1R. In co-expression studies, the D84E, R151C, I155T and R160W variants showed a dominant negative effect on wild-type receptor cell surface expression, which was reflected in a decreased ability to elevate intracellular cAMP levels. The D294H variant also demonstrated a dominant negative effect on wild-type MC1R cAMP signalling, but had no effect on wild-type surface expression. Importantly, comparison of the in vitro receptor characteristics with skin and hair colour data of individuals both homozygous and heterozygous for MC1R variant alleles revealed parallels between variant MC1R cell surface expression, functional ability, dominant negative activity and their effects on human pigmentation. These findings show the first direct correlations between variant MC1R biochemical properties and pigmentation phenotype.

Receptor function, dominant negative activity and phenotype correlations for MC1R variant alleles.

The Melanocortin-1 Receptor (MC1R) is a G-protein coupled receptor, which is responsible for production of the darker eumelanin pigment and the tanning response. The MC1R gene has many polymorphisms, some of which have been linked to variation in pigmentation phenotypes within human populations. In particular, the p.D84E, p.R151C, p.R160W and p.D294 H alleles have been strongly associated with red hair, fair skin and increased skin cancer risk. These red hair colour (RHC) variants are relatively well described and are thought to result in altered receptor function, while still retaining varying levels of signaling ability in vitro. The mouse Mc1r null phenotype is yellow fur colour, the p.R151C, p.R160W and p.D294 H alleles were able to partially rescue this phenotype, leading to the question of what the true null phenotype of MC1R would be in humans. Due to the rarity of MC1R null alleles in human populations, they have only been found in the heterozygous state until now. We report here the first case of a homozygous MC1R null individual, phenotypic analysis indicates that red hair and fair skin is found in the absence of MC1R function.

Red hair is the null phenotype of MC1R.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear hormone receptor (NHR) superfamily of ligand-activated transcriptional regulators. Accumulating evidence suggests that PPARgamma agonists such as the thiazolidinediones (TZDs) may prove to be useful anti-cancer agents exhibiting anti-proliferative and/or pro-apoptotic affects in a range of cancer cell types including melanoma, however, the mechanisms underlying this effect remain unclear. We have demonstrated the anti-proliferative effects of full and partial PPARgamma modulators in human melanoma cell lines. Ablation of PPARgamma expression in the MM96L melanoma cell line by siRNA mediated mechanisms attenuates the anti-proliferative effect of these agents suggesting this effect is directly mediated by PPARgamma. The mechanisms underlying the anti-proliferative effects of PPARgamma in melanoma cells involve the regulation of expression of a number of critical cell cycle genes and beta-catenin. Moreover, our data indicate that PPARgamma modulates Wnt/beta-catenin mediated signalling in melanoma cells in an agonist dependent manner.

PPARgamma agonists attenuate proliferation and modulate Wnt/beta-catenin signalling in melanoma cells.

The melanocortin-1 receptor (MC1R) is a key gene involved in the regulation of melanin synthesis and encodes a G-protein coupled receptor expressed on the surface of the melanocyte in the skin and hair follicles. MC1R activation after ultraviolet radiation exposure results in the production of the dark eumelanin pigment and the tanning process in humans, providing physical protection against DNA damage. The MC1R gene is highly polymorphic in Caucasian populations with a number of MC1R variant alleles associated with red hair, fair skin, freckling, poor tanning, and increased risk of melanoma and nonmelanoma skin cancer. Variant receptors have shown alterations in biochemical function, largely due to intracellular retention or impaired G-protein coupling, but retain some signaling ability. The association of MC1R variant alleles with skin cancer risk remains after correction for pigmentation phenotype, indicating regulation of nonpigmentary pathways. Notably, MC1R activation has been linked to DNA repair and may also contribute to the regulation of immune responses.

The melanocortin-1 receptor gene polymorphism and association with human skin cancer.

&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x662F; G &#x86CB;&#x767D;&#x8026;&#x5408;&#x5728;&#x76AE;&#x80A4;&#x548C;&#x5934;&#x53D1;&#x7684;&#x9ED1;&#x7D20;&#x7EC6;&#x80DE;&#x4E2D;&#x8868;&#x8FBE;&#x7684;&#x53D7;&#x4F53;&#x548C;&#x4EBA;&#x7C7B;&#x8272;&#x7D20;&#x6C89;&#x7740;&#x7684;&#x89C4;&#x7BA1;&#x65B9;&#x9762;&#x53D1;&#x6325;&#x91CD;&#x8981;&#x4F5C;&#x7528;&#x800C;&#x95FB;&#x540D;&#x3002;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x6FC0;&#x6D3B;&#x540E;&#x7D2B;&#x5916;&#x7EBF;&#x8F90;&#x5C04;&#x66B4;&#x9732;&#x7ED3;&#x679C;&#x4E2D;&#x8F6C;&#x4E3A;&#x68D5;&#x8272;/&#x9ED1;&#x8272; eumelanin &#x8272;&#x7D20;&#x5408;&#x6210;&#x76AE;&#x80A4;&#x9ED1;&#x7D20;&#x7EC6;&#x80DE; &#xFF1B; &#x5185;&#x7684;&#x7EA2;&#x8272;/&#x9EC4;&#x8272; pheomelanin&#x8FD9;&#x79CD;&#x8272;&#x7D20;&#x7136;&#x540E;&#x4F20;&#x8F93;&#x5230;&#x5468;&#x56F4;&#x7684;&#x76AE;&#x80A4;&#x89D2;&#x8D28;&#x3002;&#x9ED1;&#x8272;&#x7D20;&#x6210;&#x719F;&#x548C;&#x5438;&#x6536;&#x7684;&#x589E;&#x52A0;&#x5C06;&#x5BFC;&#x81F4;&#x6652;&#x9ED1;&#x7684;&#x76AE;&#x80A4;&#xFF0C;&#x63D0;&#x4F9B; DNA &#x635F;&#x4F24;&#x7684;&#x76AE;&#x80A4;&#x7EC6;&#x80DE;&#x514D;&#x53D7;&#x7D2B;&#x5916;&#x7EBF;&#x8F90;&#x5C04;&#x7684;&#x7269;&#x7406;&#x4FDD;&#x62A4;&#x3002;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x591A;&#x6001;&#x6027;&#x5341;&#x5206;&#x5E7F;&#x6CDB;&#xFF0C;&#x5728;&#x767D;&#x4EBA;&#x4EBA;&#x53E3;&#x548C;&#x4E00;&#x4E9B;&#x53D8;&#x578B;&#x7684;&#x7B49;&#x4F4D;&#x57FA;&#x56E0;&#x90FD;&#x4E0E;&#x7EA2;&#x8272;&#x7684;&#x5934;&#x53D1;&#x989C;&#x8272;&#x3001; &#x767D;&#x76AE;&#x80A4;&#x3001; &#x5DEE;&#x97A3;&#x548C;&#x589E;&#x52A0;&#x7684;&#x60A3;&#x76AE;&#x80A4;&#x764C;&#x7684;&#x98CE;&#x9669;&#x76F8;&#x5173;&#x8054;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x5C06;&#x8BA8;&#x8BBA;&#x4F7F;&#x7528;&#x9F20;&#x6807;&#x4E0A;&#x8863;&#x989C;&#x8272;&#x6A21;&#x578B;&#x3001; &#x4EBA;&#x7C7B;&#x7684;&#x9057;&#x4F20;&#x5173;&#x8054;&#x7814;&#x7A76;&#x548C;&#x4F53;&#x5916;&#x7EC6;&#x80DE;&#x57F9;&#x517B;&#x7814;&#x7A76;&#xFF0C;&#x4EE5;&#x786E;&#x5B9A;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x548C;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x53D8;&#x5F02;&#x7B49;&#x4F4D;&#x57FA;&#x56E0;&#x548C;&#x7EA2;&#x5934;&#x53D1;&#x989C;&#x8272;&#x8868;&#x578B;&#x4E4B;&#x95F4;&#x7684;&#x5173;&#x8054;&#x7684;&#x57FA;&#x672C;&#x5206;&#x5B50;&#x673A;&#x5236;&#x7684;&#x590D;&#x6742;&#x529F;&#x80FD;&#x3002;&#x6700;&#x8FD1;&#x7684;&#x7814;&#x7A76;&#x8868;&#x660E;&#xFF0C;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x6709;&#x5F88;&#x591A;&#x975E;&#x8272;&#x7D20;&#x6027;&#x529F;&#x80FD;&#xFF0C;&#x5E76;&#x589E;&#x52A0;&#x7684;&#x60A3;&#x76AE;&#x80A4;&#x764C;&#x7684;&#x98CE;&#x9669;&#x8D4B;&#x4E88;&#x7684;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x53D8;&#x5F02;&#x7B49;&#x4F4D;&#x57FA;&#x56E0;&#x662F;&#x5728;&#x67D0;&#x79CD;&#x7A0B;&#x5EA6;&#x4E0A;&#x72EC;&#x7ACB;&#x4E8E;&#x8272;&#x7D20;&#x6C89;&#x7740;&#x578B;&#x3002;&#x65B0;&#x578B;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x53CD;&#x5E94;&#x57FA;&#x56E0;&#x7684;&#x7814;&#x7A76;&#x548C;&#x4F7F;&#x7528;&#x66F4;&#x5148;&#x8FDB;&#x7684;&#x4EBA;&#x4F53;&#x76AE;&#x80A4;&#x6A21;&#x578B;&#xFF0C;&#x5982;&#xFF1A; 3D &#x76AE;&#x80A4;&#x91CD;&#x5EFA;&#x65B0;&#x7684;&#x8F6C;&#x57FA;&#x56E0;&#x5C0F;&#x9F20;&#x6A21;&#x578B;&#x7684;&#x4F7F;&#x7528;&#xFF0C;&#x53EF;&#x63D0;&#x4F9B;&#x4E86;&#x89E3;&#x4EBA;&#x7C7B;&#x9ED1;&#x76AE; MC(1) &#x53D7;&#x4F53;&#x591A;&#x6001;&#x6027;&#x9057;&#x4F20;&#x836F;&#x7406;&#x5B66;&#x7684;&#x5173;&#x952E;&#x8981;&#x7D20;&#x3002;

&#x9ED1;&#x76AE; MC&#x2081; &#x53D7;&#x4F53;&#x5728;&#x4EBA;&#x7C7B;&#x9057;&#x4F20;&#x5B66;&#x548C;&#x7CFB;&#x7EDF;&#x6A21;&#x578B;&#x3002;

The melanocortin MC(1) receptor is a G-protein coupled receptor expressed in the melanocytes of the skin and hair and is known for its key role in the regulation of human pigmentation. Melanocortin MC(1) receptor activation after ultraviolet radiation exposure results in a switch from the red/yellow pheomelanin to the brown/black eumelanin pigment synthesis within cutaneous melanocytes; this pigment is then transferred to the surrounding keratinocytes of the skin. The increase in melanin maturation and uptake results in tanning of the skin, providing a physical protection of skin cells from ultraviolet radiation induced DNA damage. Melanocortin MC(1) receptor polymorphism is widespread within the Caucasian population and some variant alleles are associated with red hair colour, fair skin, poor tanning and increased risk of skin cancer. Here we will discuss the use of mouse coat colour models, human genetic association studies, and in vitro cell culture studies to determine the complex functions of the melanocortin MC(1) receptor and the molecular mechanisms underlying the association between melanocortin MC(1) receptor variant alleles and the red hair colour phenotype. Recent research indicates that melanocortin MC(1) receptor has many non-pigmentary functions, and that the increased risk of skin cancer conferred by melanocortin MC(1) receptor variant alleles is to some extent independent of pigmentation phenotypes. The use of new transgenic mouse models, the study of novel melanocortin MC(1) receptor response genes and the use of more advanced human skin models such as 3D skin reconstruction may provide key elements in understanding the pharmacogenetics of human melanocortin MC(1) receptor polymorphism.

Melanocortin MCâ‚ receptor in human genetics and model systems.

Gestionaire m&eacute;lanocortine r&eacute;cepteur est une prot&eacute;ine G coupl&eacute; des r&eacute;cepteurs exprim&eacute;s dans les m&eacute;lanocytes de la peau et les cheveux et est connue pour son r&ocirc;le cl&eacute; dans la r&eacute;gulation de la pigmentation humaine. L&#39;activation des r&eacute;cepteurs m&eacute;lanocortine MC apr&egrave;s l&#39;exposition au rayonnement ultraviolet entra&icirc;ne le passage de la phaeom&eacute;lanine rouge/jaune &agrave; la synth&egrave;se du pigment brun/noir eum&eacute;lanine dans les m&eacute;lanocytes cutan&eacute;s ; ce pigment est ensuite transf&eacute;r&eacute; vers les k&eacute;ratinocytes environnants de la peau. Bronzage de la peau, en fournissant qu&#39;une protection physique des cellules de la peau des rayons ultraviolets a induit des l&eacute;sions de l&#39;ADN entra&icirc;ne l&#39;augmentation de la maturation de la m&eacute;lanine et l&#39;absorption. Gestionaire de la m&eacute;lanocortine r&eacute;cepteur polymorphisme est largement r&eacute;pandue au sein de la population caucasienne et certains all&egrave;les variant sont associ&eacute;s &agrave; la couleur de cheveux roux, peau claire, bronzage m&eacute;diocre et un risque accru de cancer de la peau. Ici nous discuterons de l&#39;utilisation de mod&egrave;les de couleur de manteau souris, &eacute;tudes d&#39;association g&eacute;n&eacute;tique humaine et &eacute;tudes sur la culture cellulaire in vitro afin de d&eacute;terminer les fonctions complexes de la m&eacute;lanocortine Gestionaire r&eacute;cepteurs et les m&eacute;canismes mol&eacute;culaires qui sous-tendent l&#39;association entre le Gestionaire de m&eacute;lanocortine r&eacute;cepteur variante all&egrave;les et le ph&eacute;notype de couleur de cheveux roux. Une recherche r&eacute;cente indique que m&eacute;lanocortine r&eacute;cepteur de MC a de nombreuses fonctions non pigmentaires et que le risque accru de cancer de la peau conf&eacute;r&eacute;e par all&egrave;les variant de m&eacute;lanocortine gestionaire du r&eacute;cepteur est dans une certaine mesure ind&eacute;pendante des ph&eacute;notypes de la pigmentation. L&#39;utilisation de nouveaux mod&egrave;les de souris transg&eacute;niques, l&#39;&eacute;tude des g&egrave;nes de r&eacute;ponse roman m&eacute;lanocortine gestionaire du r&eacute;cepteur et l&#39;utilisation des mod&egrave;les de peau humaine plus avanc&eacute;s comme la reconstruction 3D de la peau peuvent fournir des &eacute;l&eacute;ments cl&eacute;s dans la compr&eacute;hension de la pharmacog&eacute;n&eacute;tique de polymorphisme de m&eacute;lanocortine humaine gestionaire du r&eacute;cepteur.

R&eacute;cepteur de la m&eacute;lanocortine MC&#x2081; en g&eacute;n&eacute;tique humaine et les syst&egrave;mes mod&egrave;les.

Der Melanocortin-MC(1)-Rezeptor ist ein G-Protein-gekoppelte Rezeptor ausgedr&uuml;ckt in den Melanozyten der Haut und der Haare und ist bekannt f&uuml;r seine zentrale Rolle bei der Regulierung der menschlichen Pigmentierung. Melanocortin-MC(1)-Rezeptor-Aktivierung nach UV-Exposition f&uuml;hrt zu einem Wechsel von rot/gelb-Pheomelanin zu Eumelanin braun/schwarz-Pigment-Synthese innerhalb kutane Melanozyten; Dieses Pigment wird dann in die umgebenden Keratinozyten der Haut &uuml;bertragen. Die Zunahme Melanin Reifung und Aufnahme f&uuml;hrt Br&auml;unung der Haut, stellt, dass ein physischer Schutz der Haut vor UV-Strahlung induzierten DNA-Sch&auml;den. MC(1) Melanocortin-Rezeptor-Polymorphismus ist weit verbreitet in der kaukasischen Bev&ouml;lkerung und einige variant Allele mit rote Haarfarbe, helle Haut, schlechte Gerben und erh&ouml;htes Risiko von Hautkrebs verbunden sind. Hier besprechen wir die Verwendung von Mantel Farbe Mausmodelle, menschliche genetische Assoziation Studien und Untersuchungen in vitro Zell komplexen Funktionen der Melanocortin-MC(1)-Rezeptor und die molekularen Mechanismen der Assoziation zwischen Melanocortin MC(1) Rezeptor variant Allele und der rote Haare Farbe Ph&auml;notyp bestimmen. J&uuml;ngsten Forschungsergebnissen zufolge Melanocortin-MC(1)-Rezeptor viele Funktionen, nicht-Pigment hat, und, dass das erh&ouml;hte Risiko von Hautkrebs durch Melanokortin MC(1) Rezeptor variant Allele &uuml;bertragenen in gewissem Ma&szlig;e unabh&auml;ngig von der Pigmentierung Ph&auml;notypen ist. Die Verwendung von neuen transgenen Mausmodelle, k&ouml;nnen das Studium der neuartigen Melanocortin MC(1) Rezeptor Antwort Gene und die Verwendung von erweiterten menschlichen Haut Modelle wie 3D Haut Wiederaufbau Schl&uuml;sselelemente f&uuml;r das Verst&auml;ndnis der Pharmakogenetik der menschlichen Melanocortin-MC(1)-Rezeptor-Polymorphie vorsehen.

Melanocortin MC&#x2081; Rezeptor in der Humangenetik und Modellsystemen.

Il recettore di melanocortina MC(1) &egrave; una proteina G accoppiata recettore espresso nei melanociti della pelle e dei capelli ed &egrave; noto per il suo ruolo chiave nella regolazione della pigmentazione umana. Attivazione del recettore melanocortina MC(1) dopo l&#39;esposizione alle radiazioni ultraviolette si traduce in un interruttore dalla feomelanina giallo/rosso per la sintesi del pigmento eumelanina marrone/nero all&#39;interno dei melanociti cutanei; questo pigmento viene poi trasferito i cheratinociti circostanti della pelle. L&#39;aumento della melanina maturazione e diffusione risultati nella concia della pelle, fornendo una protezione fisica delle cellule della pelle da radiazione ultravioletta indotta da danni al DNA. Polimorfismo del recettore di melanocortina MC(1) &egrave; molto diffusa nella popolazione caucasica e qualche variante alleli sono associati con il colore rosso dei capelli, pelle chiara, scarsa abbronzatura e aumentato rischio di cancro della pelle. Qui discuteremo l&#39;utilizzo di modelli murini cappotto colore, studi di associazione genetica umana e gli studi di cultura cellulare in vitro per determinare le funzioni complesse del recettore melanocortina MC(1) e i meccanismi molecolari alla base dell&#39;associazione tra gli alleli varianti del recettore MC(1) melanocortina e il fenotipo colore rosso dei capelli. Recenti ricerche indicano che recettore di melanocortina MC(1) ha molte funzioni non-pigmentaria, e che l&#39;aumento del rischio di cancro della pelle conferito dalla varianti alleli di melanocortina MC(1) recettore &egrave; in qualche misura indipendente di fenotipi di pigmentazione. L&#39;utilizzo dei nuovi modelli murini transgenici, lo studio dei geni di risposta melanocortina romanzo MC(1) del recettore e l&#39;utilizzo dei pi&ugrave; avanzati modelli di pelle umana come la ricostruzione 3D della pelle pu&ograve; fornire elementi chiave nella comprensione della farmacogenetica del polimorfismo del recettore di melanocortina umano MC(1).

Recettore di melanocortina MC&#x2081; in genetica umana e sistemi di modello.

&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x306F;&#x3001;G &#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x5171;&#x5F79;&#x578B;&#x53D7;&#x5BB9;&#x4F53;&#x3067;&#x808C;&#x3084;&#x9AEA;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B5;&#x30A4;&#x30C8;&#x3092;&#x8868;&#x73FE;&#x3057;&#x3001;&#x305D;&#x306E;&#x4EBA;&#x9593;&#x306E;&#x8272;&#x7D20;&#x6C88;&#x7740;&#x306E;&#x898F;&#x5236;&#x3067;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x3092;&#x77E5;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x3067;&#x3059;&#x3002;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x6D3B;&#x6027;&#x5316;&#x7D2B;&#x5916;&#x7DDA;&#x66B4;&#x9732;&#x5F8C;&#x306E;&#x8D64;/&#x9EC4;&#x30D5;&#x30A7;&#x30AA;&#x304B;&#x3089;&#x30D6;&#x30E9;&#x30A6;&#x30F3;/&#x30D6;&#x30E9;&#x30C3;&#x30AF; &#x30E6;&#x30FC;&#x30E1;&#x30E9;&#x30CB;&#x30F3;&#x8272;&#x7D20;&#x5408;&#x6210;&#x76AE;&#x819A;&#x30E1;&#x30E9;&#x30CE;&#x30B5;&#x30A4;&#x30C8;&#x5185;&#x3078;&#x306E;&#x5207;&#x308A;&#x66FF;&#x3048;&#x306E;&#x7D50;&#x679C;;&#x3053;&#x306E;&#x8272;&#x7D20;&#x306F;&#x3001;&#x76AE;&#x819A;&#x306E;&#x5468;&#x56F2;&#x306E;&#x30B1;&#x30E9;&#x30C1;&#x30CE; &#x30B5;&#x30A4;&#x30C8;&#x306B;&#x8EE2;&#x9001;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;&#x30E1;&#x30E9;&#x30CB;&#x30F3;&#x306E;&#x6210;&#x719F;&#x3068;&#x5438;&#x53CE;&#x306E;&#x5897;&#x52A0;&#x7269;&#x7406;&#x7684;&#x306A;&#x4FDD;&#x8B77;&#x7D2B;&#x5916;&#x7DDA;&#x304B;&#x3089;&#x808C;&#x7D30;&#x80DE;&#x306E; DNA &#x640D;&#x50B7;&#x8A98;&#x767A;&#x3092;&#x63D0;&#x4F9B;&#x3059;&#x308B;&#x3001;&#x76AE;&#x819A;&#x306E;&#x65E5;&#x713C;&#x3051;&#x306E;&#x7D50;&#x679C;&#x3057;&#x307E;&#x3059;&#x3002;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x591A;&#x578B;&#x304C;&#x767D;&#x4EBA;&#x4EBA;&#x53E3;&#x5185;&#x3067;&#x666E;&#x53CA;&#x3057;&#x3066;&#x3044;&#x308B;&#x3057;&#x3001;&#x3044;&#x304F;&#x3064;&#x304B;&#x306E;&#x30D0;&#x30EA;&#x30A2;&#x30F3;&#x30C8;&#x306E;&#x5BFE;&#x7ACB;&#x907A;&#x4F1D;&#x5B50;&#x304C;&#x8D64;&#x3044;&#x9AEA;&#x306E;&#x8272;&#x3001;&#x516C;&#x6B63;&#x306A;&#x808C;&#x3001;&#x8CA7;&#x3057;&#x3044;&#x65E5;&#x713C;&#x3051;&#x3084;&#x76AE;&#x819A;&#x304C;&#x3093;&#x306E;&#x30EA;&#x30B9;&#x30AF;&#x5897;&#x52A0;&#x306B;&#x95A2;&#x9023;&#x4ED8;&#x3051;&#x3089;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3053;&#x3053;&#x3067;&#x6211;&#x3005; &#x306F;&#x30DE;&#x30A6;&#x30B9; &#x30B3;&#x30FC;&#x30C8;&#x8272;&#x30E2;&#x30C7;&#x30EB;&#x3001;&#x4EBA;&#x9593;&#x306E;&#x907A;&#x4F1D;&#x7684;&#x95A2;&#x9023;&#x7814;&#x7A76;&#x3001;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x3068;&#x305D;&#x306E;&#x5206;&#x5B50;&#x30E1;&#x30AB;&#x30CB;&#x30BA;&#x30E0; &#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x306E;&#x30D0;&#x30EA;&#x30A2;&#x30F3;&#x30C8;&#x306E;&#x5BFE;&#x7ACB;&#x907A;&#x4F1D;&#x5B50;&#x3068;&#x8D64;&#x3044;&#x9AEA;&#x8272;&#x8868;&#x73FE;&#x578B;&#x9593;&#x306E;&#x95A2;&#x9023;&#x4ED8;&#x3051;&#x306E;&#x8907;&#x96D1;&#x306A;&#x6A5F;&#x80FD;&#x3092;&#x6C7A;&#x5B9A;&#x3059;&#x308B; in vitro &#x306B;&#x304A;&#x3051;&#x308B;&#x7D30;&#x80DE;&#x57F9;&#x990A;&#x7814;&#x7A76;&#x306E;&#x4F7F;&#x7528;&#x306B;&#x3064;&#x3044;&#x3066;&#x8AAC;&#x660E;&#x3057;&#x307E;&#x3059;&#x3002;&#x6700;&#x8FD1;&#x306E;&#x7814;&#x7A76;&#x306F;&#x3001;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x975E;&#x8272;&#x7D20;&#x306E;&#x95A2;&#x6570;&#x3092;&#x591A;&#x6570;&#x6709;&#x3059;&#x308B;&#x76AE;&#x819A;&#x304C;&#x3093;&#x306E;&#x30EA;&#x30B9;&#x30AF;&#x5897;&#x52A0;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x30D0;&#x30EA;&#x30A2;&#x30F3;&#x30C8;&#x5BFE;&#x7ACB;&#x907A;&#x4F1D;&#x5B50;&#x306B;&#x3088;&#x3063;&#x3066;&#x6388;&#x4E0E;&#x3067;&#x3059;&#x3042;&#x308B;&#x7A0B;&#x5EA6;&#x306E;&#x8272;&#x7D20;&#x6C88;&#x7740;&#x306E;&#x8868;&#x73FE;&#x578B;&#x306E;&#x72EC;&#x7ACB;&#x3057;&#x305F;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x307E;&#x3059;&#x3002;&#x65B0;&#x3057;&#x3044;&#x30C8;&#x30E9;&#x30F3;&#x30B9;&#x30B8;&#x30A7;&#x30CB;&#x30C3;&#x30AF; &#x30DE;&#x30A6;&#x30B9; &#x30E2;&#x30C7;&#x30EB;&#x306E;&#x4F7F;&#x7528;&#x3001;&#x5C0F;&#x8AAC;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x5FDC;&#x7B54;&#x907A;&#x4F1D;&#x5B50;&#x306E;&#x7814;&#x7A76;&#x304A;&#x3088;&#x3073; 3 D &#x76AE;&#x819A;&#x5FA9;&#x8208;&#x306A;&#x3069;&#x306E;&#x3088;&#x308A;&#x9AD8;&#x5EA6;&#x306A;&#x3072;&#x3068;&#x76AE;&#x819A;&#x30E2;&#x30C7;&#x30EB;&#x306E;&#x4F7F;&#x7528;&#x85AC;&#x7406;&#x4EBA;&#x9593;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC(1) &#x53D7;&#x5BB9;&#x4F53;&#x591A;&#x578B;&#x306E;&#x7406;&#x89E3;&#x3059;&#x308B;&#x4E0A;&#x3067;&#x91CD;&#x8981;&#x306A;&#x8981;&#x7D20;&#x3092;&#x63D0;&#x4F9B;&#x3067;&#x304D;&#x307E;&#x3059;&#x3002;

&#x4EBA;&#x985E;&#x907A;&#x4F1D;&#x5B66;&#x304A;&#x3088;&#x3073;&#x30E2;&#x30C7;&#x30EB; &#x30B7;&#x30B9;&#x30C6;&#x30E0;&#x306B;&#x304A;&#x3051;&#x308B;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; MC&#x2081; &#x53D7;&#x5BB9;&#x4F53;&#x3002;

Melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4;&#xB294; G-&#xB2E8;&#xBC31;&#xC9C8; &#xACB0;&#xD569; &#xC218;&#xC6A9; &#xCCB4; &#xD53C;&#xBD80;&#xC640; &#xBA38;&#xB9AC;&#xCE74;&#xB77D;&#xC758; melanocytes &#xD45C;&#xD604; &#xBC0F; &#xC778;&#xAC04; &#xCC29; &#xC0C9;&#xC758; &#xB808; &#xADE4; &#xB808;&#xC774; &#xC158;&#xC758; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC5D0; &#xB300; &#xD55C; &#xC54C;&#xB824;&#xC838; &#xC788;&#xB2E4;. Melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xD65C;&#xC131;&#xD654; &#xC790;&#xC678;&#xC120; &#xB178;&#xCD9C; &#xD6C4; &#xD53C;&#xBD80; melanocytes; &#xB0B4; &#xAC08;&#xC0C9;/&#xAC80;&#xC740;&#xC0C9; &#xC774;&#xB77C;&#xACE0; &#xC0C9;&#xC18C; &#xD569;&#xC131;&#xC5D0; &#xBE68;&#xAC04;&#xC0C9;/&#xB178;&#xB780;&#xC0C9; pheomelanin&#xC5D0;&#xC11C; &#xC2A4;&#xC704;&#xCE58; &#xACB0;&#xACFC; &#xC774; &#xC548;&#xB8CC;&#xB294; &#xD53C;&#xBD80;&#xC758; &#xC8FC;&#xBCC0; keratinocytes &#xB2E4;&#xC74C; &#xC804;&#xC1A1; &#xB429;&#xB2C8;&#xB2E4;. &#xBA5C; &#xB77C; &#xB2CC; &#xC131;&#xC219;&#xACFC; &#xC774;&#xD574;&#xC758; &#xC99D;&#xAC00; &#xC81C;&#xACF5; &#xD558;&#xB294; &#xBB3C;&#xB9AC;&#xC801; &#xBCF4;&#xD638; &#xC790;&#xC678;&#xC120;&#xC5D0;&#xC11C; &#xD53C;&#xBD80; &#xC138;&#xD3EC;&#xC758; DNA &#xC190;&#xC0C1;&#xC744; &#xC720;&#xBC1C; &#xD53C;&#xBD80; &#xC120;&#xD0E0; &#xACB0;&#xACFC;. Melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xB2E4;&#xD615;&#xC131; &#xBC31;&#xC778; &#xC778;&#xAD6C; &#xB0B4;&#xC5D0;&#xC11C; &#xAD11;&#xBC94;&#xC704; &#xD558; &#xAC8C; &#xC774;&#xBA70; &#xC77C;&#xBD80; &#xBCC0;&#xD615; &#xB300;&#xB9BD; &#xBE68;&#xAC04; &#xBA38;&#xB9AC; &#xC0C9;&#xC0C1;&#xACFC; &#xD770; &#xD53C;&#xBD80;, &#xBD88; &#xC30D; &#xD55C; &#xC120;&#xD0E0; &#xD53C;&#xBD80; &#xC554; &#xC704;&#xD5D8; &#xC99D;&#xAC00;&#xC640; &#xAD00;&#xB828; &#xB41C;. &#xC5EC;&#xAE30; &#xC6B0;&#xB9AC;&#xB294; &#xB9C8;&#xC6B0;&#xC2A4; &#xCF54;&#xD2B8; &#xCEEC;&#xB7EC; &#xBAA8;&#xB378;, &#xC778;&#xAC04;&#xC758; &#xC720;&#xC804;&#xC790; &#xD611;&#xD68C; &#xC5F0;&#xAD6C; &#xBC0F; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xBD84;&#xC790; &#xBA54;&#xCEE4;&#xB2C8;&#xC998; &#xAE30;&#xBCF8; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xBCC0;&#xD615; &#xB300;&#xB9BD; &#xD558; &#xACE0; &#xBE68;&#xAC04; &#xBA38;&#xB9AC; &#xCEEC;&#xB7EC; &#xD45C;&#xD604; &#xD615; &#xC0AC;&#xC774;&#xC758; &#xC5F0;&#xACB0;&#xC758; &#xBCF5;&#xC7A1; &#xD55C; &#xAE30;&#xB2A5;&#xC744; &#xD655;&#xC778; &#xD558;&#xAE30; &#xC704;&#xD574; &#xC0DD;&#xCCB4; &#xC678; &#xC138;&#xD3EC; &#xBB38;&#xD654; &#xC5F0;&#xAD6C;&#xC758; &#xC0AC;&#xC6A9;&#xC744; &#xC124;&#xBA85; &#xD569;&#xB2C8;&#xB2E4;. &#xCD5C;&#xADFC; &#xC5F0;&#xAD6C;&#xAC00; &#xB098;&#xD0C0;&#xB0C5;&#xB2C8;&#xB2E4; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4;&#xB294; &#xB9CE;&#xC740; &#xBE44; &#xC0C9;&#xC18C; &#xAE30;&#xB2A5; &#xCC29; &#xC0C9; &#xACE0;&#xAE30;&#xC5D0; &#xAD00;&#xACC4; &#xC5C6;&#xC774; &#xC5B4;&#xB290; &#xC815;&#xB3C4; &#xD53C;&#xBD80; &#xC554; &#xC704;&#xD5D8; &#xC99D;&#xAC00; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xBCC0;&#xD615; &#xB300;&#xB9BD;&#xC5D0; &#xC758;&#xD574; &#xC218; &#xC5EC;. &#xC0C8;&#xB85C;&#xC6B4; &#xC720;&#xC804;&#xC790; &#xBCC0;&#xD615; &#xB9C8;&#xC6B0;&#xC2A4; &#xBAA8;&#xB378;&#xC758; &#xC0AC;&#xC6A9;, &#xC18C;&#xC124; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xBC18;&#xC751; &#xC720;&#xC804;&#xC790; &#xC5F0;&#xAD6C;&#xC640; 3D &#xD53C;&#xBD80; &#xC7AC;&#xAC74; &#xB4F1; &#xACE0;&#xAE09; &#xC778;&#xAC04;&#xC758; &#xD53C;&#xBD80; &#xBAA8;&#xB378; &#xC0AC;&#xC6A9; &#xC778;&#xAC04;&#xC758; melanocortin MC(1) &#xC218;&#xC6A9; &#xCCB4; &#xB2E4;&#xD615;&#xC131; pharmacogenetics &#xC774;&#xD574;&#xC758; &#xD575;&#xC2EC; &#xC694;&#xC18C;&#xB97C; &#xC81C;&#xACF5;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;.

&#xC778;&#xAC04; &#xC720;&#xC804;&#xD559; &#xBC0F; &#xBAA8;&#xB378; &#xC2DC;&#xC2A4;&#xD15C;&#xC5D0;&#xC11C; Melanocortin MC&#x2081; &#xC218;&#xC6A9; &#xCCB4;.

El receptor de melanocortina MC(1) es una prote&iacute;na G acoplados a receptores expresados en los melanocitos de la piel y el cabello y es conocida por su papel clave en la regulaci&oacute;n de la pigmentaci&oacute;n humana. Activaci&oacute;n del receptor de melanocortina si despu&eacute;s de exposici&oacute;n a la radiaci&oacute;n ultravioleta resulta en un cambio desde la feomelanina rojo/amarillo a la s&iacute;ntesis de pigmento eumelanina marr&oacute;n/negro dentro de los melanocitos cut&aacute;neos; Este pigmento se transfiere a los queratinocitos circundantes de la piel. El aumento en la maduraci&oacute;n de la melanina y la absorci&oacute;n resulta en el curtido de la piel, proporcionando una protecci&oacute;n f&iacute;sica de las c&eacute;lulas de la piel de la radiaci&oacute;n ultravioleta inducida por da&ntilde;o en el ADN. Polimorfismo de receptores de melanocortina si es generalizada en la poblaci&oacute;n cauc&aacute;sica y algunos alelos variantes se asocian con el color de pelo rojo, piel, bronceado pobre y mayor riesgo de c&aacute;ncer de piel. Aqu&iacute; vamos a discutir el uso de modelos de color de capa de rat&oacute;n, estudios de asociaci&oacute;n gen&eacute;tica humana y estudios en cultivos celulares in vitro para determinar las funciones complejas de los receptores de melanocortina MC(1) y los mecanismos moleculares subyacentes a la asociaci&oacute;n entre alelos variantes del receptor de melanocortina MC(1) y el fenotipo de color de pelo rojo. Investigaciones recientes indican que receptores de melanocortina MC(1) tiene muchas funciones no pigmentarias, y que el mayor riesgo de c&aacute;ncer de piel conferido por alelos variantes del receptor de melanocortina MC(1) es hasta cierto punto independiente de fenotipos de pigmentaci&oacute;n. El uso de nuevos modelos de rat&oacute;n transg&eacute;nico, el estudio de genes de respuesta de receptores de melanocortina novela MC(1) y el uso de modelos m&aacute;s avanzados de la piel humana como reconstrucci&oacute;n 3D de la piel pueden proporcionar elementos clave en la comprensi&oacute;n de la farmacogen&eacute;tica de polimorfismo de receptores de melanocortina humano MC(1).

Receptor de melanocortina MC&#x2081; en gen&eacute;tica humana y sistemas modelo.

Rab GTPases including Rab27a, Rab38 and Rab32 function in melanosome maturation or trafficking in melanocytes. A screen to identify additional Rabs involved in these processes revealed the localization of GFP-Rab17 on recycling endosomes (REs) and melanosomes in melanocytic cells. Rab17 mRNA expression is regulated by microphthalmia transcription factor (MITF), a characteristic of known pigmentation genes. Rab17 siRNA knockdown in melanoma cells quantitatively increased melanosome concentration at the cell periphery. Rab17 knockdown did not inhibit melanosome maturation nor movement, but it caused accumulation of melanin inside cells. Double knockdown of Rab17 and Rab27a indicated that Rab17 acts on melanosomes downstream of Rab27a. Filopodia are known to play a role in melanosome transfer, and in Rab17 knockdown cells filopodia formation was inhibited. Furthermore, we show that stimulation of melanoma cells with α-melanocyte-stimulating hormone induces filopodia formation, supporting a role for filopodia in melanosome release. Cell stimulation also caused redistribution of REs to the periphery, and knockdown of additional RE-associated Rabs 11a and 11b produced a similar accumulation of melanosomes and melanin to that seen after loss of Rab17. Our findings reveal new functions for RE and Rab17 in pigmentation through a distal step in the process of melanosome release via filopodia.

The recycling endosome protein Rab17 regulates melanocytic filopodia formation and melanosome trafficking.

&#x800C;&#x523A;&#x9F20;&#x4FE1;&#x53F7;&#x86CB;&#x767D;&#x53CD;&#x5411;&#x6FC0;&#x52A8;&#x5242;&#x7ED3;&#x679C; pheomelanin &#x5408;&#x6210;&#x7684;&#x5177;&#x6709;&#x7EA6;&#x675F;&#x529B;&#x7684;&#x9ED1;&#x76AE;&#x80BD;&#x53D7;&#x4F53;&#x6FC0;&#x52A8;&#x5242;&#x5BF9;&#x9ED1;&#x7D20;&#x7EC6;&#x80DE;&#x4E2D;&#x7684;&#x7ED3;&#x679C; eumelanin &#x751F;&#x4EA7;&#x7684;&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53;&#x5177;&#x6709;&#x7EA6;&#x675F;&#x529B;&#x3002;&#x6700;&#x8FD1;&#xFF0C;&#x636E;&#x62A5;&#x9053;&#x4E00;&#x79CD;&#x65B0;&#x578B;&#x7684;&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53;&#x914D;&#x4F53;&#x3002;&Beta;-&#x9632;&#x5FA1;&#x7D20;&#x57FA;&#x56E0;&#x7A81;&#x53D8;&#x88AB;&#x53D1;&#x73B0;&#x8981;&#x8D1F;&#x8D23;&#x56FD;&#x5185;&#x72AC;&#x9ED1;&#x8272;&#x7684;&#x6BDB;&#x8272;&#x3002;&#x503C;&#x5F97;&#x6CE8;&#x610F;&#x7684;&#x662F;&#xFF0C;&#x7B49;&#x6548;&#x3001; &beta;-&#x9632;&#x5FA1;&#x7D20; 3 &#x4EBA;&#x88AB;&#x53D1;&#x73B0;&#x8981;&#x7ED1;&#x5B9A;&#x5230;&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53; &#xFF1B; &#x9AD8;&#x4EB2;&#x548C;&#x529B;&#x4F46;&#x662F;&#xFF0C;&#x4F5C;&#x4E3A;&#x4E00;&#x4E2A;&#x6FC0;&#x52A8;&#x5242;&#x6216;&#x62EE;&#x6297;&#x5242; &beta;-&#x9632;&#x5FA1;&#x7D20;&#x7684;&#x884C;&#x52A8;&#x662F;&#x672A;&#x77E5;&#x7684;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#xFF0C;&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x4F53;&#x5916;&#x68C0;&#x6D4B;&#x663E;&#x793A;&#xFF0C;&beta;-&#x9632;&#x5FA1;&#x7D20; 3 &#x662F;&#x80FD;&#x591F;&#x5145;&#x5F53;&#x8584;&#x5F31;&#x7684;&#x90E8;&#x5206;&#x6FC0;&#x52A8;&#x5242;&#x5728;&#x8425;&#x5730;&#x4FE1;&#x53F7;&#x5728;&#x4EBA;&#x80DA;&#x80CE;&#x80BE; (&#x7EC6;&#x80DE;) &#x7EC6;&#x80DE;&#x8868;&#x8FBE;&#x4EBA;&#x7C7B;&#x9ED1;&#x7D20;&#x76AE;&#x8D28;&#x7D20;-1 &#x53D7;&#x4F53;&#x3002;&Beta;-&#x9632;&#x5FA1;&#x7D20; 3 &#x4E5F;&#x662F;&#x80FD;&#x591F;&#x6FC0;&#x6D3B; MAPK &#x4FE1;&#x53F7;&#x7A33;&#x5B9A;&#x8868;&#x8FBE;&#x91CE;&#x751F;&#x578B;&#x6216;&#x5907;&#x9009;&#x6848;&#x6587;&#x7684;&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53;&#x7684;&#x7EC6;&#x80DE;&#x7EC6;&#x80DE;&#x4E2D;&#x3002;&#x6211;&#x4EEC;&#x5EFA;&#x8BAE; &beta;-&#x9632;&#x5FA1;&#x7D20; 3 &#x53EF;&#x80FD;&#x53C2;&#x4E0E;&#x8C03;&#x8282;&#x4EBA;&#x4F53;&#x5185;&#x7684;&#x9ED1;&#x7D20;&#x7EC6;&#x80DE;&#x53CD;&#x5E94;&#x65B0;&#x578B;&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53;&#x6FC0;&#x52A8;&#x5242;&#x3002;

&#x9ED1;&#x76AE;-1 &#x53D7;&#x4F53;&#x4ECB;&#x5BFC;&#x7684;&#x4FE1;&#x53F7;&#x8F6C;&#x5BFC;&#x6FC0;&#x6D3B; NDP MSH &#x548C; HBD3 &#x914D;&#x4F53;&#x3002;

Binding of melanocortin peptide agonists to the melanocortin-1 receptor of melanocytes results in eumelanin production, whereas binding of the agouti signalling protein inverse agonist results in pheomelanin synthesis. Recently, a novel melanocortin-1 receptor ligand was reported. A Î²-defensin gene mutation was found to be responsible for black coat colour in domestic dogs. Notably, the human equivalent, Î²-defensin 3, was found to bind with high affinity to the melanocortin-1 receptor; however, the action of Î²-defensin as an agonist or antagonist was unknown. Here, we use in vitro assays to show that Î²-defensin 3 is able to act as a weak partial agonist for cAMP signalling in human embryonic kidney (HEK) cells expressing human melanocortin-1 receptor. Î²-defensin 3 is also able to activate MAPK signalling in HEK cells stably expressing either wild type or variant melanocortin-1 receptors. We suggest that Î²-defensin 3 may be a novel melanocortin-1 receptor agonist involved in regulating melanocyte responses in humans.

Melanocortin-1 receptor-mediated signalling pathways activated by NDP-MSH and HBD3 ligands.

La liaison de la m&eacute;lanocortine agonistes de peptide pour le r&eacute;cepteur de la m&eacute;lanocortine-1 des r&eacute;sultats de m&eacute;lanocytes dans la production d&#39;eum&eacute;lanine, tandis que la liaison de l&#39;agouti signalisation r&eacute;sultats d&#39;agoniste inverse de prot&eacute;ine dans la synth&egrave;se de la phaeom&eacute;lanine. R&eacute;cemment, un ligand du nouveau r&eacute;cepteur de la m&eacute;lanocortine-1 a &eacute;t&eacute; signal&eacute;. Un &beta;-defensin mutation du g&egrave;ne s&#39;est av&eacute;r&eacute;e pour &ecirc;tre responsable de la couleur de manteau noir chez les chiens domestiques. Notamment, l&#39;homme 3 &eacute;quivalent, &beta;-defensin, a &eacute;t&eacute; trouv&eacute; &agrave; se lier avec une haute affinit&eacute; pour le r&eacute;cepteur de la m&eacute;lanocortine-1 ; Toutefois, l&#39;action de la &beta;-defensin comme un agoniste ou antagoniste &eacute;tait inconnue. Ici, nous utilisons des tests in vitro pour montrer que &beta;-defensin 3 est capable d&#39;agir comme un faible agoniste partiel pour le cAMP de signalisation dans le rein embryonnaire humaine (HEK) des cellules exprimant le r&eacute;cepteur humain m&eacute;lanocortine-1. &Beta;-defensin 3 est aussi capable d&#39;activer de signalisation MAPK dans les cellules HEK exprimant des r&eacute;cepteurs de type sauvage ou variante melanocortin-1 de mani&egrave;re stable. Nous sugg&eacute;rons que les &beta;-defensin 3 peut &ecirc;tre un agoniste du nouveau r&eacute;cepteur de la m&eacute;lanocortine-1 intervenant dans la r&eacute;gulation des r&eacute;ponses des m&eacute;lanocytes humains.

1-M&eacute;lanocortine m&eacute;di&eacute;e par les r&eacute;cepteurs voies de signalisation activ&eacute;es par des ligands du NPD-MSH et HBD3.

Binden von Melanocortin-Peptid-Agonisten an den Melanocortin-1-Rezeptor der Melanozyten Ergebnisse in Eumelanin Produktion, w&auml;hrend der das Aguti Signalisierung Protein inverse Agonisten Ergebnisse Pheomelanin Synthese zu binden. Vor kurzem wurde eine neuartige Melanocortin-1-Rezeptor-Ligand berichtet. Ein &beta;-defensin Genmutation wurde festgestellt, dass f&uuml;r die schwarze Fellfarbe in Haushunden verantwortlich. Vor allem wurde das menschliche &auml;quivalent, &beta;-defensin 3, festgestellt, dass mit hoher Affinit&auml;t zu den Melanocortin-1-Rezeptor binden; Allerdings war die Wirkung von &beta;-defensin als Agonist oder Antagonist unbekannt. Hier verwenden wir in-vitro-Tests um zu zeigen, dass &beta;-defensin 3 ist in der Lage zu handeln, wie ein schwacher partieller Agonist zum cAMP signalisieren von menschlichen embryonalen Niere (HEK) Ausdruck menschlichen Melanocortin-1-Rezeptor-Zellen. &Beta;-defensin 3 ist auch in der Lage, MAPK Signalisierung in HEK-Zellen stabil auszudr&uuml;cken entweder Wildtyp oder Variante Melanocortin-1 Rezeptoren zu aktivieren. Wir schlagen vor, dass &beta;-defensin 3 eine neuartige Melanocortin-1-Rezeptor-Agonisten bei der Regulierung der Melanozyten Reaktionen beim Menschen beteiligt sein k&ouml;nnen.

Melanocortin-1-Rezeptor-vermittelten Signalwege durch NDP-MSH und HBD3 Liganden aktiviert.

Associazione di agonisti del peptide melanocortina al recettore melanocortina-1 dei risultati di melanociti nella produzione di eumelanina, considerando che il grippaggio del agouti segnalazione risultati agonista inverso della proteina nella sintesi di feomelanina. Recentemente, &egrave; stato segnalato un ligando del recettore di melanocortina-1 romanzo. Un &beta;-defensina mutazione del gene &egrave; stato trovato per essere responsabile del colore del cappotto nero in cani domestici. In particolare, &egrave; stato trovato l&#39;umano 3 equivalente, defensina &beta;, di legare con alta affinit&agrave; per il recettore di melanocortina-1; Tuttavia, l&#39;azione della &beta;-defensina come agonista o un antagonista era sconosciuto. Qui, usiamo i saggi in vitro per mostrare che &beta;-defensina 3 &egrave; in grado di agire come un debole agonista parziale per la segnalazione del cAMP nel rene embrionale umano (HEK) le cellule che esprimono recettore di melanocortina-1 umano. &Beta;-defensina 3 &egrave; anche in grado di attivare la segnalazione MAPK in cellule HEK stabile che esprimono recettori melanocortin-1 wild type o variante. Suggeriamo che 3 defensina &beta; pu&ograve; essere un agonista del recettore di melanocortina-1 romanzo coinvolto nella regolazione di risposte di melanociti negli esseri umani.

Percorsi segnalazione mediata dal recettore di melanocortina-1 attivato da NDP-MSH e HBD3 ligandi.

&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; &#x30DA;&#x30D7;&#x30C1;&#x30C9;&#x306E;&#x30A2;&#x30B4;&#x30CB;&#x30B9;&#x30C8; &#x30E1;&#x30E9;&#x30CE;&#x30B5;&#x30A4;&#x30C8;&#x7D50;&#x679C;&#x30E6;&#x30FC;&#x30E1;&#x30E9;&#x30CB;&#x30F3;&#x751F;&#x7523;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x306E;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;&#x9006;&#x30A2;&#x30B4;&#x30CB;&#x30B9;&#x30C8;&#x7D50;&#x679C;&#x30D5;&#x30A7;&#x30AA; &#x30E1;&#x30E9;&#x30CB;&#x30F3;&#x5408;&#x6210;&#x306B;&#x304A;&#x3051;&#x308B; agouti &#x306E;&#x7D50;&#x5408;&#x306B;&#x5BFE;&#x3057;&#x3092;&#x30D0;&#x30A4;&#x30F3;&#x30C9;&#x3057;&#x307E;&#x3059;&#x3002;&#x6700;&#x8FD1;&#x3001;&#x65B0;&#x898F;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x304C;&#x5831;&#x544A;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&Beta; &#x30C7;&#x30A3;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3;&#x907A;&#x4F1D;&#x5B50;&#x5909;&#x7570;&#x9ED2;&#x30B3;&#x30FC;&#x30C8;&#x3092;&#x30AB;&#x30E9;&#x30FC;&#x3067;&#x56FD;&#x5185;&#x306E;&#x72AC;&#x306E;&#x305F;&#x3081;&#x306B;&#x8CAC;&#x4EFB;&#x304C;&#x3042;&#x308B;&#x3053;&#x3068;&#x304C;&#x308F;&#x304B;&#x3063;&#x305F;&#x3002;&#x7279;&#x306B;&#x3001;&#x4EBA;&#x9593;&#x3068;&#x540C;&#x7B49;&#x3001;&beta; &#x30C7;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3;&#x306E; 3 &#x9AD8;&#x89AA;&#x548C;&#x6027;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x306B;&#x7D50;&#x5408;&#x3059;&#x308B;&#x767A;&#x898B;&#x3055;&#x308C;&#x305F;;&#x3057;&#x304B;&#x3057;&#x3001;&beta; &#x30C7;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3;&#x306E;&#x4F5C;&#x7528;&#x30A2;&#x30F3;&#x30BF;&#x30B4;&#x30CB;&#x30B9;&#x30C8;&#x307E;&#x305F;&#x306F;&#x30A2;&#x30B4;&#x30CB;&#x30B9;&#x30C8;&#x3068;&#x3057;&#x3066;&#x306F;&#x77E5;&#x3089;&#x308C;&#x3066;&#x3044;&#x305F;&#x3002;&#x3053;&#x3053;&#x3067;&#x306F;&#x3001;&#x751F;&#x4F53;&#x5916;&#x306E;&#x8A66;&#x91D1;&#x306F; &beta; &#x30C7;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3;&#x3092;&#x793A;&#x3059;&#x305F;&#x3081;&#x4F7F;&#x7528;&#x3057;&#x3066; 3 &#x306F;&#x4EBA;&#x9593;&#x306E;&#x840C;&#x82BD;&#x671F;&#x814E;&#x81D3; (HEK) cAMP &#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x306E;&#x5F31;&#x3044;&#x90E8;&#x5206;&#x30A2;&#x30B4;&#x30CB;&#x30B9;&#x30C8;&#x3092;&#x8868;&#x73FE;&#x3059;&#x308B;&#x3072;&#x3068;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x7D30;&#x80DE;&#x3068;&#x3057;&#x3066;&#x884C;&#x52D5;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x307E;&#x3059;&#x3002;&Beta; &#x30C7;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3; 3 &#x307E;&#x305F;&#x5B89;&#x5B9A;&#x306B;&#x91CE;&#x751F;&#x578B;&#x307E;&#x305F;&#x306F;&#x30D0;&#x30EA;&#x30A2;&#x30F3;&#x30C8;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x767A;&#x73FE;&#x3059;&#x308B; HEK &#x7D30;&#x80DE;&#x306B;&#x304A;&#x3051;&#x308B; MAPK &#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x3092;&#x30A2;&#x30AF;&#x30C6;&#x30A3;&#x30D6;&#x306B;&#x3059;&#x308B;&#x3053;&#x3068;&#x3067;&#x3059;&#x3002;3 &Beta; &#x30C7;&#x30D5;&#x30A7;&#x30F3;&#x30B7;&#x30F3;&#x4EBA;&#x9593;&#x306E;&#x30E1;&#x30E9;&#x30CE;&#x30B5;&#x30A4;&#x30C8;&#x5FDC;&#x7B54;&#x306E;&#x8ABF;&#x7BC0;&#x306B;&#x95A2;&#x4E0E;&#x3059;&#x308B;&#x65B0;&#x898F;&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x30A2;&#x30B4;&#x30CB;&#x30B9;&#x30C8;&#x3053;&#x3068;&#x304C;&#x793A;&#x5506;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;

&#x30E1;&#x30E9;&#x30CE;&#x30B3;&#x30EB;&#x30C1;&#x30F3; 1 &#x53D7;&#x5BB9;&#x4F53;&#x3092;&#x4ECB;&#x3057;&#x305F;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x7D4C;&#x8DEF; NDP MSH &#x3068; HBD3 &#x306B;&#x3088;&#x3063;&#x3066;&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x3092;&#x6D3B;&#x6027;&#x5316;&#x3002;

&#xBC18;&#xBA74; &#xB2E8;&#xBC31;&#xC9C8; &#xC5ED; &#xAE38; &#xD56D; &#xC81C; &#xACB0;&#xACFC;: pheomelanin &#xD569;&#xC131; &#xC2E0;&#xD638; agouti&#xC758; &#xBC14;&#xC778;&#xB529; &#xC774;&#xB77C;&#xACE0; &#xC0DD;&#xC0B0; melanocytes &#xACB0;&#xACFC;&#xC758; melanocortin-1 &#xC218;&#xC6A9; &#xCCB4;&#xB97C; melanocortin &#xD3A9; &#xD2F0; &#xB4DC; agonists&#xC758; &#xBC14;&#xC778;&#xB529;. &#xCD5C;&#xADFC;, &#xC18C;&#xC124; melanocortin-1 &#xC218;&#xC6A9; &#xCCB4; ligand&#xAC00; &#xC54C;&#xB824;&#xC84C;&#xB2E4;. &Beta; defensin &#xC720;&#xC804;&#xC790; &#xB3CC;&#xC5F0;&#xBCC0;&#xC774; &#xAD6D;&#xB0B4; &#xAC1C;&#xC5D0; &#xAC80;&#xC740; &#xCF54;&#xD2B8; &#xC0C9;&#xC0C1;&#xC5D0; &#xB300; &#xD55C; &#xCC45;&#xC784;&#xC744; &#xC9C8; &#xAC83;&#xC744; &#xBC1C;&#xACAC; &#xD588;&#xB2E4;. &#xD2B9;&#xD788;, &#xC778;&#xAC04;&#xC758; &#xB3D9;&#xB4F1;&#xD55C;, &beta; defensin 3 melanocortin-1 &#xC218;&#xC6A9; &#xCCB4;;&#xC5D0; &#xB192;&#xC740; &#xC120;&#xD638;&#xB3C4;&#xC640; &#xBC14;&#xC778;&#xB529;&#xD558;&#xB294; &#xB370; &#xBC1C;&#xACAC; &#xADF8;&#xB7EC;&#xB098;, &#xAE38; &#xD56D; &#xC81C; &#xB610;&#xB294; &#xAE38; &#xD56D; &#xC81C;&#xB294; &beta; defensin &#xD589;&#xB3D9; &#xC54C;&#xB824;&#xC9C0;&#xC9C0; &#xC54A;&#xC558;&#xB2E4;. &Beta; defensin &#xBCF4;&#xC5EC;&#xC8FC;&#xB294; &#xC0DD;&#xCCB4; &#xC678; &#xBD84;&#xC11D; &#xC2E4;&#xD5D8;&#xC744; &#xC0AC;&#xC6A9; &#xD558;&#xB294; &#xC5EC;&#xAE30;&#xC5D0;, 3 &#xC778;&#xAC04;&#xC758; &#xBC30;&#xC544; &#xC2E0;&#xC7A5; (HEK)&#xC5D0;&#xC11C; &#xCEA0;&#xD504; &#xC2E0;&#xD638;&#xC5D0; &#xB300; &#xD55C; &#xC57D;&#xD55C; &#xBD80;&#xBD84; &#xAE38; &#xD56D; &#xC81C; &#xD45C;&#xD604; &#xC778;&#xAC04;&#xC758; melanocortin-1 &#xC218;&#xC6A9; &#xCCB4; &#xC138;&#xD3EC;&#xAC00; &#xD558;&#xB294; &#xC5ED;&#xD560;&#xC744; &#xC218; &#xC788;&#xB2E4;. &Beta; defensin 3&#xC740; &#xB610;&#xD55C; MAPK &#xC548;&#xC815;&#xC801; &#xC640;&#xC77C;&#xB4DC; &#xD615;&#xC2DD;&#xC774; &#xB098; variant melanocortin-1 &#xC218;&#xC6A9; &#xCCB4;&#xB97C; &#xD45C;&#xD604; &#xD558;&#xB294; HEK &#xC138;&#xD3EC;&#xC5D0; &#xC2E0;&#xD638;&#xB97C; &#xD65C;&#xC131;&#xD654;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. 3 &Beta; defensin &#xC778;&#xAC04;&#xC5D0;&#xC11C; melanocyte &#xC751;&#xB2F5; &#xC870;&#xC808;&#xC5D0; &#xAD00;&#xB828; &#xB41C; &#xC18C;&#xC124; melanocortin-1 &#xC218;&#xC6A9; &#xCCB4; &#xAE38; &#xD56D; &#xC81C;&#xB294; &#xC788;&#xC744; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; &#xD558;&#xB294; &#xAC83;&#xC774; &#xC88B;&#xC2B5;&#xB2C8;&#xB2E4;.

Melanocortin-1 &#xC218;&#xC6A9; &#xCCB4;-&#xC911;&#xC7AC; &#xC2E0;&#xD638; &#xACBD;&#xB85C; ligands &#xC2E0; &#xBBFC; &#xB2F9;-MSH&#xC640; hbd3&#xC5D0; &#xC758;&#xD574; &#xD65C;&#xC131;&#xD654;.

Encuadernaci&oacute;n de agonistas del p&eacute;ptido de melanocortina al receptor de la melanocortina-1 de los resultados de melanocitos en la producci&oacute;n de eumelanina, mientras que del agut&iacute; se&ntilde;alizaci&oacute;n resultados de agonista inverso de prote&iacute;nas en la s&iacute;ntesis de feomelanina. Recientemente, fue divulgado un ligando del receptor de melanocortina-1 novela. Un &beta;-defensina de gene fue encontrado para ser responsable del color de la capa negra en perros dom&eacute;sticos. En particular, el ser humano equivalente, &beta;-defensina 3, se encontr&oacute; que se unen con alta afinidad a los receptores de melanocortina-1; sin embargo, la acci&oacute;n de la &beta;-defensina como agonista o antagonista era desconocida. Aqu&iacute;, utilizamos ensayos in vitro para demostrar que &beta;-defensina 3 es capaz de actuar como agonista parcial d&eacute;bil para la se&ntilde;alizaci&oacute;n de campamento en ri&ntilde;&oacute;n embrionario humano (HEK) c&eacute;lulas expresando su receptor de melanocortina-1 humano. &Beta;-defensina 3 tambi&eacute;n es capaz de activar la se&ntilde;alizaci&oacute;n MAPK en c&eacute;lulas HEK estable que expresan receptores de melanocortina-1 tipo salvaje o variante. Sugerimos que &beta;-defensina 3 puede ser agonista del receptor de melanocortina-1 novela de implicados en la regulaci&oacute;n de las respuestas de melanocitos en los seres humanos.

V&iacute;as de se&ntilde;alizaci&oacute;n mediada por receptor melanocortin-1 activan por el NDP-MSH y HBD3 ligandos.

Samaniego et al. (this issue) report on distinct tumor-associated mesenchymal cell (MC) populations in human melanomas. FAP(-)CD90(+) peritumoral MCs may be involved in immune cell recruitment from the bloodstream. FAP(+)CD90(-) intratumoral MCs were associated with extracellular matrix fiber deposition, and their numbers correlated with high immune cell infiltration. Thus, different MC subsets modulate the cellular composition of the intratumoral and peritumoral melanoma microenvironment.

Mesenchymal cells hold the key to immune cell recruitment to and migration within melanoma.

Amino acids, especially leucine and glutamine, are important for tumor cell growth, survival and metabolism. A range of different transporters deliver each specific amino acid into cells, some of which are increased in cancer. These amino acids consequently activate the mTORC1 pathway and drive cell cycle progression. The leucine transporter LAT1/4F2hc heterodimer assembles as part of a large complex with the glutamine transporter ASCT2 to transport amino acids. In this study, we show that the expression of LAT1 and ASCT2 is significantly increased in human melanoma samples and is present in both BRAF(WT) (C8161 and WM852) and BRAF(V600E) mutant (1205Lu and 451Lu) melanoma cell lines. While inhibition of LAT1 by BCH did not suppress melanoma cell growth, the ASCT2 inhibitor BenSer significantly reduced both leucine and glutamine transport in melanoma cells, leading to inhibition of mTORC1 signaling. Cell proliferation and cell cycle progression were significantly reduced in the presence of BenSer in melanoma cells in 2D and 3D cell culture. This included reduced expression of the cell cycle regulators CDK1 and UBE2C. The importance of ASCT2 expression in melanoma was confirmed by shRNA knockdown, which inhibited glutamine uptake, mTORC1 signaling and cell proliferation. Taken together, our study demonstrates that ASCT2-mediated glutamine transport is a potential therapeutic target for both BRAF(WT) and BRAF(V600E) melanoma.

Targeting glutamine transport to suppress melanoma cell growth.

Solid cancers are composed of heterogeneous zones containing proliferating and quiescent cells. Despite considerable insight into the molecular mechanisms underlying aberrant cell cycle progression, there is limited understanding of the relationship between the cell cycle on the one side, and melanoma cell motility, invasion, and drug sensitivity on the other side. Utilizing the fluorescent ubiquitination-based cell cycle indicator (FUCCI) to longitudinally monitor proliferation and migration of melanoma cells in 3D culture and in vivo, we found that invading melanoma cells cycle actively, while G1-arrested cells showed decreased invasion. Melanoma cells in a hypoxic environment or treated with mitogen-activated protein kinase pathway inhibitors remained G1-arrested for extended periods of time, with proliferation and invasion resuming after re-exposure to a more favorable environment. We challenge the idea that the invasive and proliferative capacity of melanoma cells are mutually exclusive and further demonstrate that a reversibly G1-arrested subpopulation survives in the presence of targeted therapies.

Kimberley A. Beaumont

The Centenary Institute

Imaging- and Flow Cytometry-based Analysis of Cell Position and the Cell Cycle in 3D Melanoma Spheroids