Name: flow cytometry to estimate leukemia stem cells in primary acute myeloid leukemia and in patient-derived-xenografts, at diagnosis and follow up
Uploaded: 2018-03-26T13:00:00
Description: Watch this Scientific Journal Video about Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up at JoVE.com

This work was in part supported by the French Association Laurette Fugain, LigueContre le Cancer (North Center), Fondation de France (Leukemia Committee), SIRIC Oncolille, and French National Cancer Institute.

We follow European standards for the use of animals for scientific purposes. This study was approved by the local Ethics committee (#3097-2015120414583482v3).
1. Sample preparation
<ol>
	<li>Collect bone marrow (2 mL) from de novo AML in tubes containing the anticoagulant ethylenediaminetetraacetic acid&#160;(EDTA) at a concentration of 1.8 mg per mL of bone marrow.</li>
	<li>Perform Ficoll separation, a density gradient separation to isolate mononuclear cells from red cells and gra...

<ol>
	<li>Shlush, L. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracing+the+origins+of+relapse+in+acute+myeloid+leukaemia+to+stem+cells.">Tracing the origins of relapse in acute myeloid leukaemia to stem cells.</a> Nature. , (2017).</li><li>Terwijn, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leukemic+stem+cell+frequency:+a+strong+biomarker+for+clinical+outcome+in+acute+myeloid+leukemia.">Leukemic stem cell frequency: a strong biomarker for clinical outcome in acute myeloid leukemia.</a> PLoS One. 9 (9), e107587 (2014).</li><li>Jordan, C. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+interleukin-3+receptor+alpha+chain+is+a+unique+marker+for+human+acute+myelogenous+leukemia+stem+cells.">The interleukin-3 receptor alpha chain is a unique marker for human acute myelogenous leukemia stem cells.</a> Leukemia. 14 (10), 1777-1784 (2000).</li><li>van Rhenen, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+novel+AML+stem+cell+associated+antigen+CLL-1+aids+in+discrimination+between+normal+and+leukemic+stem+cells.">The novel AML stem cell associated antigen CLL-1 aids in discrimination between normal and leukemic stem cells.</a> Blood. 110 (7), 2659-2666 (2007).</li><li>Bonardi, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+proteomics+and+transcriptomics+approach+to+identify+leukemic+stem+cell+(LSC)+markers.">A proteomics and transcriptomics approach to identify leukemic stem cell (LSC) markers.</a> Mol Cell Proteomics. 12 (3), 626-637 (2013).</li><li>Kikushige, Y., Miyamoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+TIM-3+as+a+Leukemic+Stem+Cell+Surface+Molecule+in+Primary+Acute+Myeloid+Leukemia.">Identification of TIM-3 as a Leukemic Stem Cell Surface Molecule in Primary Acute Myeloid Leukemia.</a> Oncology. 89, 28-32 (2015).</li><li>Bonnet, D., Dick, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+acute+myeloid+leukemia+is+organized+as+a+hierarchy+that+originates+from+a+primitive+hematopoietic+cell.">Human acute myeloid leukemia is organized as a hierarchy that originates from a primitive hematopoietic cell.</a> Nat Med. 3 (7), 730-737 (1997).</li><li>Kersten, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CD45RA,+a+specific+marker+for+leukaemia+stem+cell+sub-populations+in+acute+myeloid+leukaemia.">CD45RA, a specific marker for leukaemia stem cell sub-populations in acute myeloid leukaemia.</a> Brit J Haematol. 173 (2), 219-235 (2016).</li><li>Goardon, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coexistence+of+LMPP-like+and+GMP-like+leukemia+stem+cells+in+acute+myeloid+leukemia.">Coexistence of LMPP-like and GMP-like leukemia stem cells in acute myeloid leukemia.</a> Cancer Cell. 19 (1), 138-152 (2011).</li><li>Ng, S. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+17-gene+stemness+score+for+rapid+determination+of+risk+in+acute+leukaemia.">A 17-gene stemness score for rapid determination of risk in acute leukaemia.</a> Nature. 540 (7633), 433-437 (2016).</li><li>Shultz, L. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+lymphoid+and+myeloid+cell+development+in+NOD/LtSz-scid+IL2R+gamma+null+mice+engrafted+with+mobilized+human+hemopoietic+stem+cells.">Human lymphoid and myeloid cell development in NOD/LtSz-scid IL2R gamma null mice engrafted with mobilized human hemopoietic stem cells.</a> J. Immunol. 174 (10), 6477-6489 (2005).</li><li>Roloff, G. W., Lai, C., Hourigan, C. S., Dillon, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technical+Advances+in+the+Measurement+of+Residual+Disease+in+Acute+Myeloid+Leukemia.">Technical Advances in the Measurement of Residual Disease in Acute Myeloid Leukemia.</a> J Clin Med. 6 (9), (2017).</li><li>Swamydas, S., Lionakis, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation,+Purification+and+Labeling+of+Mouse+Bone+Marrow+Neutrophils+for+Functional+Studies+and+Adoptive+Transfer+Experiments.">Isolation, Purification and Labeling of Mouse Bone Marrow Neutrophils for Functional Studies and Adoptive Transfer Experiments.</a> J Vis Exp. (77), e50586 (2013).</li><li>Gabert, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardization+and+quality+control+studies+of+'real-time'+quantitative+reverse+transcriptase+polymerase+chain+reaction+of+fusion+gene+transcripts+for+residual+disease+detection+in+leukemia+-+a+Europe+Against+Cancer+program.">Standardization and quality control studies of 'real-time' quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia - a Europe Against Cancer program.</a> Leukemia. 17 (12), 2318-2357 (2003).</li></ol>

An accurate and reproducible assessment of membrane or cytoplasmic markers by flow cytometry requires that instrument settings are verified every day for optical alignment, proper functioning of the fluidic system,&#160; optical sensitivity, and standardization using calibration beads.
Detection of blast cell populations in AML using CD90 and CD45RA by multi-parametric flow cytometry analysis is a relatively simple and reliable method. A critical step in this analysis is an accurate assessment...

Acute myeloid leukemia (AML) is the most common cause of leukemia-associated mortality. Initially, AML is a clonal disease of hematopoietic stem cells (HSC) characterized by arrest of differentiation, subsequent accumulation of blast cells, and reduced production of functional hematopoietic elements. Recently, clonal heterogeneity of the blast cell population has been established essentially by using next generation sequencing (NGS) strategies and showing the existence of intra-clonal evolution of tumor cells1.
Heterogeneity extends to the presence of leukemic stem cells (LSC). It is hypothesized that this dynamic cell compartment evolves to overcome various selection pressures imposed upon during leukemia progression and treatment. Therefore LSC are supposed to be resistant to current chemotherapeutic regimens and mediate disease relapse, with profound clinical implications2. Various markers have been described to characterize LSC like CD1233, CLL-14, CD975 or TIM-36. The CD34+CD38- compartment of blast cells is considered to be enriched for LSC7 but also includes normal HSC. CD90 and CD45RA expression applied to the CD34+CD38- (P6) compartment (Figure 1) permits to segregate several stages of normal and malignant hematopoietic precursors8. Specifically, normal CD34+CD38-CD90+CD45RA- HSCs, multipotent progenitors (MPP) like CD34+CD38-CD90dimCD45RA- cells and CD34+CD38-CD90-CD45RA+ lymphoid-primed multipotent progenitor (LMPP) cells can be determined in the majority of AML cases8,9. The mean fluorescence intensity (MFI) of CD38 is particularly important to be considered within the CD34+ cell compartment. Because CD38 intensity defines three new cell compartments thereof: CD38 negative (P6), CD38 dim (P7) and CD38 bright (P8) (Figure 1). The MFI of CD38 may be determined using either hematogones and/or plasma cells as an internal positive control as these cells strongly express CD38.
The immunodeficient NOD/SCID/IL2R&#947;cnull (NSG) mouse model is widely used for engraftment of normal and malignant human hematopoietic cells10,11. Serial xenotransplantation assays are used to experimentally validate LSC or HSC function. These studies have been extensively analyzed by large scale sequencing approaches. Nevertheless, less is known about the LSC and HSC immunophenotype of AML blast population engrafted into NSG mice compared to its primary AML (Figure 2).
The numbers of LSC are inherently low thus, identification and quantification of LSC are challenging and the method described here may be used as a flow cytometric assay at diagnosis and at clinical follow up to evaluate chemotherapy response (as residual LSC may cause AML relapse). The presence of LSC may indicate positive minimal residual disease (MRD). To date,&#160; MRD monitoring in AML mostly rely on molecular methods (i.e., RT-PCR, NGS)10,12. However, in this protocol we detect simultaneous protein expression of several HSC/LSC markers (CD34, CD38, CD45RA, CD90) on primary blast cells of human AML by multiparametric flow cytometry2,8,9. This combination of antibodies may be applied in any standard flow cytometry laboratory and this flow MRD assay is particularly interesting when MRD by real-time polymerase chain reaction (RT-PCR) is not possible, i.e., if&#160; leukemia specific molecular markers are not detectable in the diagnostic AML sample. Furthermore, this protocol, is complementary to the more sensitive molecular MRD techniques, as it aims to detect and quantify the abnormal hematopoietic progenitor cells which represents a functional cell characteristic (Figure 3).
We show how to quantify three hematopoietic progenitor populations and the putative LSC compartment with different degree of maturation by flow cytometry with antibodies available in the majority of clinical laboratories. Furthermore, we confirmed the presence of these cell compartments in corresponding patient-derived-xenografts (PDX) and at treatment follow up.

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			<td height="20" style="height:21px;width:363px;">Pancoll</td>
			<td style="width:189px;">PAN-Biotech</td>
			<td style="width:128px;">P04-60500</td>
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			<td height="75" style="height:75px;">RBC Lysis Buffer (10x)</td>
			<td>Ozyme</td>
			<td>BLE420301</td>
			<td style="width:467px;">RBC Lysis solution A : 8.29 g of NH4Cl + 0.037 g of Na2EDTA in 100 mL of sterile H2O and RBC Lysis solution B: 1 g of KHCO3 in 100 mL of sterile H2O</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">NOD/SCID/IL2R&#947;cnull&#160; (NSG)&#160; mice</td>
			<td>JACKSON LABORATORY</td>
			<td>Stock No: 005557</td>
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			<td height="20" style="height:21px;">PBS</td>
			<td>Gibco by life technologies</td>
			<td>14190-144</td>
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			<td height="20" style="height:21px;">AutoMACS Running Buffer &#8211; MACS Separation Buffer</td>
			<td>MACS Buffer Miltenybiotec</td>
			<td>130-091-221</td>
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			<td height="20" style="height:21px;">Anti-CD36-FITC (clone FA6-152, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>PN IM0766U</td>
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			<td height="20" style="height:21px;">Anti-CD33-PC5.5 (clone D3HL60.251, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>B36289</td>
			<td style="width:467px;"></td>
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			<td height="20" style="height:21px;">Anti-CD90-APC (clone 5E10)</td>
			<td>Biolegend</td>
			<td>328114</td>
			<td style="width:467px;"></td>
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			<td height="20" style="height:21px;">Anti-CD19-ECD (clone J3-119, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>A07770</td>
			<td style="width:467px;"></td>
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		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD34-AA700 (clone 581, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>B92417</td>
			<td style="width:467px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD45RA-APC-H7 (clone HI100)&#160;</td>
			<td>Beckton Dickinson</td>
			<td>560674</td>
			<td style="width:467px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD38-Pacific Blue (clone LSI98-4-3, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>B92396</td>
			<td style="width:467px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD45-KO (clone J.33, Iotest)</td>
			<td>Beckman Coulter</td>
			<td>B36294</td>
			<td style="width:467px;"></td>
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		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD3-PE</td>
			<td>Beckman Coulter</td>
			<td>IM1451</td>
			<td></td>
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		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD20-PE</td>
			<td>Beckman Coulter</td>
			<td>A07747</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-CD123-PC7</td>
			<td>Beckman Coulter</td>
			<td>B13647</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Flow-Set</td>
			<td>Beckman Coulter</td>
			<td>A63492</td>
			<td style="width:467px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Flow-Check</td>
			<td>Beckman Coulter</td>
			<td>A63493</td>
			<td style="width:467px;"></td>
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		<tr height="20">
			<td height="20" style="height:21px;">Navios</td>
			<td>Beckman Coulter</td>
			<td>DS-14644A</td>
			<td style="width:467px;"></td>
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		<tr height="20">
			<td height="20" style="height:21px;">LSR Fortessa X20</td>
			<td>BD Biosciences</td>
			<td></td>
			<td></td>
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			<td height="20" style="height:21px;">CST BD</td>
			<td>BD Biosciences</td>
			<td>655051</td>
			<td></td>
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		<tr height="20">
			<td height="20" style="height:21px;">FacsFlow&#160;</td>
			<td>BD Biosciences</td>
			<td>336911</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-hCD45-FITC</td>
			<td>Biolegend</td>
			<td>BLE304006</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Anti-mCD45-APC</td>
			<td>Biolegend</td>
			<td>BLE103112</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">EasySep human PE selection kit</td>
			<td>Stem Cell Technologies</td>
			<td>18000</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">EasySep&#160; magnet&#160;</td>
			<td>Stem Cell Technologies</td>
			<td>18551</td>
			<td></td>
		</tr>
	</tbody>
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flow cytometry to estimate leukemia stem cells in primary acute myeloid leukemia and in patient-derived-xenografts, at diagnosis and follow up

Acute myeloid leukemia (AML) is a heterogeneous, and if not treated, fatal disease. It is the most common cause of leukemia-associated mortality in adults. Initially, AML is a disease of hematopoietic stem cells (HSC) characterized by arrest of differentiation, subsequent accumulation of leukemia blast cells, and reduced production of functional hematopoietic elements. Heterogeneity extends to the presence of leukemia stem cells (LSC), with this dynamic cell compartment evolving to overcome various selection pressures imposed upon during leukemia progression and treatment. To further define the LSC population, the addition of CD90 and CD45RA allows the discrimination of normal HSCs and multipotent progenitors within the CD34+CD38- cell compartment. Here, we outline a protocol to detect simultaneous expression of several putative LSC markers (CD34, CD38, CD45RA, CD90) on primary blast cells of human AML by multiparametric flow cytometry. Furthermore, we show how to quantify three progenitor populations and a putative LSC population with increasing degree of maturation. We confirmed the presence of these populations in corresponding patient-derived-xenografts. This method of detection and quantification of putative LSC may be used for clinical follow-up of chemotherapy response (i.e., minimal residual disease), as residual LSC may cause AML relapse.

Here we present a method to determine progenitor populations in normal and malignant human bone marrow samples. We collected bone marrow and spleen from a successful PDX and performed multiparametric flow cytometry as described above. We compared several subpopulations of blast cells between the diagnostic patient sample and the corresponding PDX and particularly, the CD34+CD38- progenitor compartment, notably enriched in putative LSC. We have found that the CD34+CD38- blast fraction was higher in PDX compared to the dia...

Watch this Scientific Journal Video about Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up at JoVE.com

Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up

We outline a protocol to detect simultaneous expression of leukemia stem cell markers on primary acute myeloid leukemia cells by flow cytometry. We show how to quantify three progenitor populations and a putative LSC population with increasing degree of maturation. We confirmed the presence of these populations in corresponding patient-derived-xenografts.

Acute myeloid leukemia (AML) is a heterogeneous, and if not treated, fatal disease. It is the most common cause of leukemia-associated mortality in ...

The overall goal of this procedure is to estimate leukemia stem cells in acute myeloid leukemia and in patient-derived-xenografts by flow cytometry at diagnosis and at treatment follow up. This method can answer key questions in the hematology/oncology field, such as the clinical relevance of the quantitative assessment of leukemia stem cells by flow cytometry in acute myeloid leukemia. The main advantage of this technique is that it is applicable to most hematology/oncology laboratories with commonly used antibodies.This procedure will be demonstrated by Thomas, a post-doc, Fanny, a grad student, and Adeline, an engineer from my laboratory. To begin, collect two milliliters of bone marrow from de novo AML in tubes containing 1.8 milligrams per milliliter of the anti-coagulant EDTA. Isolate mononuclear cells from red blood cells and granulocytes by first diluting bone marrow in three volumes of PBS.Then, carefully overlay one volume of ficol with one volume of diluted bone marrow. Spin the density gradient at 300g for 30 minutes without a break. Then, transfer the white buffy coat layer of mononucleated cells into a new sterile tube.To remove the supernatants contaminating serum components, add 10 milliliters of PBS and centrifuge the cells at 300g for five minutes before repeating the wash. Lyse the red blood cells by adding two milliliters of lysis buffer to the cell pellet and gently vortex. Then, incubate the cells at room temperature for five minutes.Centrifuge the cells at 300g for five minutes and remove the supernatant. Then, use PBS to wash the cells. After isolating blast cells from bone marrow according to the text protocol, under a laminar flow hood, insert an unconditioned NSG mouse into a restraining device and inject five times 10 to the sixth AML blast cells into the tail vein.Return the mouse to an individual ventilated cage under conventional and specific pathogen-free conditions. Every two weeks, use a submandibular collection method with a hematocrit capillary to draw 60 microliters of blood. Transfer the capillary into a five milliliter tube then with a sterile gauze pad, apply gentle pressure to stop the bleeding.Add one milliliter of lysis buffer to the tube and gently vortex. Then, incubate the cells at room temperature for five minutes. Centrifuge the cells at 300g for five minutes.Then, after removing the supernatant, add 100 microliters of PBS with 10%BSA, three microliters of anti-human CD45 FITC, incubate for 30 minutes. Then, wash the cell pellet two times in PBS, two milliliters, with 10%BSA and centrifuge at 300g for five minutes. Every two weeks, use flow cytometry to analyze the engraftment by chimerism analysis of human versus murine CD45 expression.When the blast count is greater than 70%or severe clinical signs of sickness are observed, sacrifice the animal and collect mononuclear blast cells from a crushed spleen and from bone marrow by using PBS to flush tibias and femurs as previously described. To carry out panel staining, combine conjugated antibodies with human primary or patient-derived-xenograft, or PDX samples, and vortex the tubes. Then, incubate the cells in the dark at room temperature for 15 to 30 minutes.Remove the unbound antibodies by using two milliliters of PBS to wash the cells. Re-suspend the cells in 450 microliters of PBS, then proceed to flow cytometry analysis and MRD monitoring. To accurately and reproducibly assess membrane of cytoplasmic markers by flow cytometry, verify optical alignment.Proper tuning of the 3D system and optical sensitivity and stomatization using stomazine calibration beats every day. Use normal bone marrow to set the gates for CD38. A minimum of 500, 000 events are required and it is verified that each flow run is regular and homogenous.In addition, doublets, as well as dead cells and cell debris are eliminated. Immature hematopoietic cells are defined by being CD45 intermediate, SSC low. And the CD38 positive control or hematogones, are CD19/CD38 double positive.Then P8 or CD38 positive, P7 or CD38 intermediate, and P6 or CD38 negative are defined. The P6 cells can be further subdivided into HSC, MPP, and LSC. Since it is a normal bone marrow it is LSC negative.Using multiparametric flow cytometry, it was found that the CD34 positive, CD38 negative blast fraction was higher in PDX compared to the diagnostic patient sample. Interestingly, a higher percentage of putative LSC was found in the PDX compared to the primary patient sample, suggesting a possible enrichment of malignant progenitor cells in the hematologic tissues in this mouse model. Upon comparison of the blast progenitor populations in two different patient samples, the CD34 positive, CD38 negative fraction increased from 0.06%at diagnosis to 3.33%at the first treatment follow-up in the first patient.In contrast, the CD34 positive, CD38 negative fraction decreased in the second patient from 7.8%at diagnosis to 2.27%at the first treatment follow-up. Accordingly, the putative LSC fraction increased in the first patient from 0%at diagnosis to 0.65%and decreased in the second patient from 6.57%at diagnosis to 1.44%at treatment follow-up. Minimal residual disease or MRD monitoring, using as molecular markers the NPM1 mutation in patient one and the CBF-beta MYH11 gene fusion for patient two showed that molecular MRD decreased less in the first patient compared to the second patient for the first treatment follow-up point.Once mastered, this technique can be done in two hours if it is performed properly. While you're attempting this procedure, it is important to verify flow cytometric settings and CD38 gauging. Following this procedure, additional methods can be performed, like flow cytometric cell sorting in order to answer additional questions like functional leukemia stem cell assess.After watching this video you should have a good understanding of how to detect and quantify leukemia stem cells in patient samples in patient-derived-xenografts. Don't forget that working with patient samples can be hazardous and precautions such as GOP guidelines and institutional safety procedures should always be taken while you are performing this procedure.

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Research

JoVE Journal

Cancer Research

Comprehensive Protocol to Sample and Process Bone Marrow for Measuring Measurable Residual Disease and Leukemic Stem Cells in Acute Myeloid Leukemia

Response criteria in acute myeloid leukemia (AML) has recently been re-established, with morphologic examination utilized to determine whether patients have achieved complete remission (CR). Approximately half of the adult patients who entered CR will relapse within 12 months due to the outgrowth of residual AML cells in the bone marrow. The quantitation of these remaining leukemia cells, known as minimal or measurable residual disease (MRD), can be a robust biomarker for the prediction of these relapses. Moreover, retrospective analysis of several studies has shown that the presence of MRD in the bone marrow of AML patients correlates with poor survival. Not only is the total leukemic population, reflected by cells harboring a leukemia associated immune-phenotype (LAIP), associated with clinical outcome, but so is the immature low frequency subpopulation of leukemia stem cells (LSC), both of which can be monitored through flow cytometry MRD or MRD-like approaches. The availability of sensitive assays that enable detection of residual leukemia (stem) cells on the basis of disease-specific or disease-associated features (abnormal molecular markers or aberrant immunophenotypes) have drastically improved MRD assessment in AML. However, given the inherent heterogeneity and complexity of AML as a disease, methods for sampling bone marrow and performing MRD and LSC analysis should be harmonized when possible. In this manuscript we describe a detailed methodology for adequate bone marrow aspirate sampling, transport, sample processing for optimal multi-color flow cytometry assessment, and gating strategies to assess MRD and LSC to aid in therapeutic decision making for AML patients.

Detection of minimal or measurable residual disease (MRD) is an important prognostic biomarker for refining risk assessment and predicting relapse in acute myeloid leukemia (AML). These comprehensive guidelines and recommendations with best practices for consistent and accurate identification and detection of MRD, may aid in making effective AML treatment decisions.

Response criteria in acute myeloid leukemia (AML) has recently been re-established, with morphologic examination utilized to determine whether patients ...

Preparation of Primary Acute Lymphoblastic Leukemia Cells in Different Cell Cycle Phases by Centrifugal Elutriation

The ability to synchronize cells has been central to advancing our understanding of cell cycle regulation. Common techniques employed include serum deprivation; chemicals which arrest cells at different cell cycle phases; or the use of mitotic shake-off which exploits their reduced adherence. However, all of these have disadvantages. For example, serum starvation works well for normal cells but less well for tumor cells with compromised cell cycle checkpoints due to oncogene activation or tumor suppressor loss. Similarly, chemically-treated cell populations can harbor drug-induced damage and show stress-related alterations. A technique which circumvents these problems is counterflow centrifugal elutriation (CCE), where cells are subjected to two opposing forces, centrifugal force and fluid velocity, which results in the separation of cells on the basis of size and density. Since cells advancing through the cycle typically enlarge, CCE can be used to separate cells into different cell cycle phases. Here we apply this technique to primary acute lymphoblastic leukemia cells. Under optimal conditions, an essentially pure population of cells in G1 phase and a highly enriched population of cells in G2/M phases can be obtained in excellent yield. These cell populations are ideally suited for studying cell cycle-dependent mechanisms of action of anticancer drugs and for other applications. We also show how modifications to the standard procedure can result in suboptimal performance and discuss the limitations of the technique. The detailed methodology presented should facilitate application and exploration of the technique to other types of cells.

This protocol describes the use of centrifugal elutriation to separate primary acute lymphoblastic leukemia cells into different cell cycle phases.

The ability to synchronize cells has been central to advancing our understanding of cell cycle regulation. Common techniques employed include serum ...

Isolation and Characterization of Tumor-initiating Cells from Sarcoma Patient-derived Xenografts

The existence and importance of tumor-initiating cells (TICs) have been supported by increasing evidence during the past decade. These TICs have been shown to be responsible for tumor initiation, metastasis, and drug resistance. Therefore, it is important to develop specific TIC-targeting therapy in addition to current chemotherapy strategies, which mostly focus on the bulk of non-TICs. In order to further understand the mechanism behind the malignancy of TICs, we describe a method to isolate and to characterize TICs in human sarcomas. Herein, we show a detailed protocol to generate patient-derived xenografts (PDXs) of human sarcomas and to isolate TICs by fluorescence-activated cell sorting (FACS) using human leukocyte antigen class I (HLA-1) as a negative marker. Also, we describe how to functionally characterize these TICs, including a sphere formation assay and a tumor formation assay, and to induce differentiation along mesenchymal pathways. The isolation and characterization of PDX TICs provide clues for the discovery of potential targeting therapy reagents. Moreover, increasing evidence suggests that this protocol may be further extended to isolate and characterize TICs from other types of human cancers.

We describe a detailed protocol for the isolation of tumor-initiating cells from human sarcoma patient-derived xenografts by fluorescence-activated cell sorting, using human leukocyte antigen-1 (HLA-1) as a negative marker, and for the further validation and characterization of these HLA-1-negative tumor-initiating cells.

The existence and importance of tumor-initiating cells (TICs) have been supported by increasing evidence during the past decade. These TICs have been ...

A Chromatin Immunoprecipitation Assay to Identify Novel NFAT2 Target Genes in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the expansion of malignant B cell clones and represents the most common leukemia in western countries. The majority of CLL patients show an indolent course of the disease as well as an anergic phenotype of their leukemia cells, referring to a B cell receptor unresponsive to external stimulation. We have recently shown that the transcription factor NFAT2 is a crucial regulator of anergy in CLL. A major challenge in the analysis of the role of a transcription factor in different diseases is the identification of its specific target genes. This is of&#160;great significance for the elucidation of pathogenetic mechanisms and potential therapeutic interventions. Chromatin immunoprecipitation (ChIP) is a classic technique to demonstrate protein-DNA interactions and can, therefore, be used to identify direct target genes of transcription factors in mammalian cells. Here, ChIP was used to identify LCK as a direct target gene of NFAT2 in human CLL cells. DNA and associated proteins are crosslinked using formaldehyde and subsequently sheared by sonication into DNA fragments of approximately 200-500 base pairs (bp). Cross-linked DNA fragments associated with NFAT2 are then selectively immunoprecipitated from cell debris using an &#945;NFAT2 antibody. After purification, associated DNA fragments are detected via quantitative real-time PCR (qRT-PCR). DNA sequences with evident enrichment represent regions of the genome which are targeted by NFAT2 in vivo. Appropriate shearing of the DNA and the selection of the required antibody are particularly crucial for the successful application of this method. This protocol is ideal for the demonstration of direct interactions of NFAT2 with target genes. Its major limitation is the difficulty to employ ChIP in large-scale assays analyzing the target genes of multiple transcription factors in intact organisms.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world. NFAT transcription factors are important regulators of development and activation in numerous cell types. Here, we present a protocol for the use of chromatin immunoprecipitation (ChIP) in human CLL cells to identify novel target genes of NFAT2.

Chronic lymphocytic leukemia (CLL) is characterized by the expansion of malignant B cell clones and represents the most common leukemia in western ...

Assessment of the Metabolic Profile of Primary Leukemia Cells

The metabolic requirement of cancer cells can negatively influence survival and treatment efficacy. Nowadays, pharmaceutical targeting of metabolic pathways is tested in many types of tumors. Thus, characterization of cancer cell metabolic setup is inevitable in order to target the correct pathway to improve the overall outcome of patients. Unfortunately, in a majority of cancers, the malignant cells are quite difficult to obtain in higher numbers and the tissue biopsy is required. Leukemia is an exception, where a sufficient number of leukemic cells can be isolated from the bone marrow. Here, we provide a detailed protocol for the isolation of leukemic cells from leukemia patients bone marrow and subsequent analysis of their metabolic state using extracellular flux analyzer. Leukemic cells are isolated by the density gradient, which does not affect their viability. The next cultivation step helps them to regenerate, thus the metabolic state measured is the state of cells in optimal conditions. This protocol allows achieving consistent, well-standardized results, which could be used for the personalized therapy.

Here we present a protocol for the isolation of leukemic cells from leukemia patients bone marrow and analysis of their metabolic state. Assessment of the metabolic profile of primary leukemia cells could help to better characterize the demand of primary cells and could lead up to more personalized medicine.

The metabolic requirement of cancer cells can negatively influence survival and treatment efficacy. Nowadays, pharmaceutical targeting of metabolic ...

Flow Cytometric Analysis of Mitochondrial Reactive Oxygen Species in Murine Hematopoietic Stem and Progenitor Cells and MLL-AF9 Driven Leukemia

We present a flow cytometric approach for analyzing mitochondrial ROS in various live bone marrow (BM)-derived stem and progenitor cell populations from healthy mice as well as mice with AML driven by MLL-AF9. Specifically, we describe a two-step cell staining process, whereby healthy or leukemia BM cells are first stained with a fluorogenic dye that detects mitochondrial superoxides, followed by staining with fluorochrome-linked monoclonal antibodies that are used to distinguish various healthy and malignant hematopoietic progenitor populations. We also provide a strategy for acquiring and analyzing the samples by flow cytometry. The entire protocol can be carried out in a timeframe as short as 3-4 h. We also highlight the key variables to consider as well as the advantages and limitations of monitoring ROS production in the mitochondrial compartment of live hematopoietic and leukemia stem and progenitor subpopulations using fluorogenic dyes by flow cytometry. Furthermore, we present data that mitochondrial ROS abundance varies among distinct healthy HSPC sub-populations and leukemia progenitors and discuss the possible applications of this technique in hematologic research.

We describe a method for using multiparameter flow cytometry to detect mitochondrial reactive oxygen species (ROS) in murine healthy hematopoietic stem and progenitor cells (HSPCs) and leukemia cells from a mouse model of acute myeloid leukemia (AML) driven by MLL-AF9.

We present a flow cytometric approach for analyzing mitochondrial ROS in various live bone marrow (BM)-derived stem and progenitor cell populations from ...

Subcellular Fractionation of Primary Chronic Lymphocytic Leukemia Cells to Monitor Nuclear/Cytoplasmic Protein Trafficking

Nuclear export of macromolecules is often deregulated in cancer cells. Tumor suppressor proteins, such as p53, can be rendered inactive due to aberrant cellular localization disrupting their mechanism of action. The survival of chronic lymphocytic leukaemia (CLL) cells, among other cancer cells, is assisted by the deregulation of nuclear to cytoplasmic shuttling, at least in part through deregulation of the transport receptor XPO1 and the constitutive activation of PI3K-mediated signaling pathways. It is essential to understand the role of individual proteins in the context of their intracellular location to gain a deeper understanding of the role of such proteins in the pathobiology of the disease. Furthermore, identifying processes that underlie cell stimulation and the mechanism of action of specific pharmacological inhibitors, in the context of subcellular protein trafficking, will provide a more comprehensive understanding of the mechanism of action. The protocol described here enables the optimization and subsequent efficient generation of nuclear and cytoplasmic fractions from primary chronic lymphocytic leukemia cells. These fractions can be used to determine changes in protein trafficking between the nuclear and cytoplasmic fractions upon cell stimulation and drug treatment. The data can be quantified and presented in parallel with immunofluorescent images, thus providing robust and quantifiable data.

This protocol enables the optimization and subsequent efficient generation of nuclear and cytoplasmic fractions from primary chronic lymphocytic leukemia cells. These samples are used to determine protein localization as well as changes in protein trafficking that take place between the nuclear and cytoplasmic compartments upon cell stimulation and drug treatment.

Nuclear export of macromolecules is often deregulated in cancer cells. Tumor suppressor proteins, such as p53, can be rendered inactive due to aberrant ...

Two Flow Cytometric Approaches of NKG2D Ligand Surface Detection to Distinguish Stem Cells from Bulk Subpopulations in Acute Myeloid Leukemia

Within the same patient, absence of NKG2D ligands (NKG2DL) surface expression was shown to distinguish leukemic subpopulations with stem cell properties (so called leukemic stem cells, LSCs) from more differentiated counterpart leukemic cells that lack disease initiation potential although they carry similar leukemia specific genetic mutations. NKG2DL are biochemically highly diverse MHC class I-like self-molecules. Healthy cells in homeostatic conditions generally do not express NKG2DL on the cell surface. Instead, expression of these ligands is induced upon exposure to cellular stress (e.g., oncogenic transformation or infectious stimuli) to trigger elimination of damaged cells via lysis through NKG2D-receptor-expressing immune cells such as natural killer (NK) cells. Interestingly, NKG2DL surface expression is selectively suppressed in LSC subpopulations, allowing these cells to evade NKG2D-mediated immune surveillance. Here, we present a side-by-side analysis of two different flow cytometry methods that allow the investigation of NKG2DL surface expression on cancer cells i.e., a method involving pan-ligand recognition and a method involving staining with multiple antibodies against single ligands. These methods can be used to separate viable NKG2DL negative cellular subpopulations with putative cancer stem cell properties from NKG2DL positive non-LSC.

We present two different staining protocols for NKG2D ligand (NKG2DL) detection in human primary acute myeloid leukemia (AML) samples. The first approach is based on a fusion protein, able to recognize all known and potentially yet unknown ligands, while the second protocol relies on the addition of multiple anti-NKG2DL antibodies.

Within the same patient, absence of NKG2D ligands (NKG2DL) surface expression was shown to distinguish leukemic subpopulations with stem cell properties ...

Intra-Peritoneal Transplantation for Generating Acute Myeloid Leukemia in Mice

There is an unmet need for novel therapies to treat acute myeloid leukemia (AML) and the associated relapse that involves persistent leukemia stem cells (LSCs). An experimental AML rodent model to test therapies based on successfully transplanting these cells via retro-orbital injections in recipient mice is fraught with challenges. The aim of this study was to develop an easy, reliable, and consistent method to generate a robust murine model of AML using an intra-peritoneal route. In the present protocol, bone marrow cells were transduced with a retrovirus expressing human MLL-AF9 fusion oncoprotein. The efficiency of lineage negative (Lin-) and Lin-Sca-1+c-Kit+ (LSK) populations as donor LSCs in the development of primary AML was tested, and intra-peritoneal injection was adopted as a new method to generate AML. Comparison between intra-peritoneal and retro-orbital injections was done in serial transplantations to compare and contrast the two methods. Both Lin- and LSK&#160;cells transduced with human MLL-AF9 virus engrafted well in the bone marrow and spleen of recipients, leading to a full-blown AML. The intra-peritoneal injection of donor cells established AML in recipients upon serial transplantation, and the infiltration of AML cells was detected in the blood, bone marrow, spleen, and liver of recipients by flow cytometry, qPCR, and histological analyses. Thus, intra-peritoneal injection is an efficient method of AML induction using serial transplantation of donor leukemic cells.

Here, intra-peritoneal injection of leukemia cells is utilized to establish and propagate acute myeloid leukemia (AML) in mice. This new method is effective in the serial transplantation of AML cells and can serve as an alternative for those who may experience difficulties and inconsistencies with intravenous injection in mice.

There is an unmet need for novel therapies to treat acute myeloid leukemia (AML) and the associated relapse that involves persistent leukemia stem cells ...

Establishment of Zebrafish Patient-Derived Xenografts from Pancreatic Cancer for Chemosensitivity Testing

Cancer is one of the main causes of death worldwide, and the incidence of many types of cancer continues to increase. Much progress has been made in terms of screening, prevention, and treatment; however, preclinical models that predict the chemosensitivity profile of cancer patients are still lacking. To fill this gap, an in vivo patient-derived xenograft model was developed and validated. The model was based on zebrafish (Danio rerio) embryos at 2 days post fertilization, which were used as recipients of xenograft fragments of tumor tissue taken from a patient's surgical specimen. 
It is also worth noting that bioptic samples were not digested or disaggregated, in order to maintain the tumor microenvironment, which is crucial in terms of analyzing tumor behavior and the response to therapy. The protocol details a method for establishing zebrafish-based patient-derived xenografts (zPDXs) from primary solid tumor surgical resection. After screening by an anatomopathologist, the specimen is dissected using a scalpel blade. Necrotic tissue, vessels, or fatty tissue are removed and then chopped into 0.3 mm x 0.3 mm x 0.3 mm pieces. 
The pieces are then fluorescently labeled and xenotransplanted into the perivitelline space of zebrafish embryos. A large number of embryos can be processed at a low cost, enabling high-throughput in vivo analyses of the chemosensitivity of zPDXs to multiple anticancer drugs. Confocal images are routinely acquired to detect and quantify the apoptotic levels induced by chemotherapy treatment compared to the control group. The xenograft procedure has a significant time advantage, since it can be completed in a single day, providing a reasonable time window to carry out a therapeutic screening for co-clinical trials.

Preclinical models aim to advance the knowledge of cancer biology and predict treatment efficacy. This paper describes the generation of zebrafish-based patient-derived xenografts (zPDXs) with tumor tissue fragments. The zPDXs were treated with chemotherapy, the therapeutic effect of which was assessed in terms of cell apoptosis of the transplanted tissue.

Cancer is one of the main causes of death worldwide, and the incidence of many types of cancer continues to increase. Much progress has been made in terms ...