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The Cutting and Floating Method for Paraffin-embedded Tissue for Sectioning

Sectioning of the paraffin-embedded tissue is widely used in histology and pathology. However, it is tedious. To improve this method, several commercial ...

Nanchang University

Dissecting the genetic basis for the evolution of species differences requires a combination of phylogenetic and molecular genetic perspectives. By mapping the genetic changes and their phenotypic effects onto the phylogeny, it is possible to distinguish changes that may have been directly responsible for a new character state from those that fine tune the transition. Here, we use phylogenetic and functional methods to trace the evolution of substrate specificity in dihydroflavonol-4-reductase (Dfr), an anthocyanin pathway gene known to be involved in the transition from blue to red flowers in Iochroma. Ancestral state reconstruction indicates that three substitutions occurred during the flower color transition, whereas several additional substitutions followed the transition. Comparisons of enzymatic function between ancestral proteins in blue- and red-flowered lineages and proteins from present-day taxa demonstrate that evolution of specificity for red pigment precursors was caused by the first three substitutions, which were fixed by positive selection and which differ from previously documented mutations affecting specificity. Two inferred substitutions subsequent to the initial flower color transition were also adaptive and resulted in an additional increase in specificity for red precursors. Epistatic interactions among both sets of substitutions may have limited the order of substitutions along branches of the phylogeny leading from blue-pigmented ancestors to the present-day red-flowered taxa. These results suggest that the species differences in DFR specificity may arise by a combination of selection on flower color and selection for improved pathway efficiency but that the exact series of genetic changes resulting in the evolution of specificity is likely to be highly contingent on the starting state.

Functional evolution of an anthocyanin pathway enzyme during a flower color transition.

This study was to enrich prostate cancer stem cells (PrCSC) from primary prostate cancer cultures (PPrCC). Primary prostate cancer cells were amplified in keratinocyte serum-free medium with epidermal growth factor (EGF) and bovine pituitary extract (BPE), supplemented with leukemia inhibitory factor (LIF), stem cell factor (SCF) and cholera toxin. After amplification, cells were transferred into ultra-low attachment dishes with serum-free DMEM/F12 medium, supplemented with EGF, basic fibroblast growth factor (bFGF), bovine serum albumin (BSA), insulin, and N2 nutrition. Expression of cell-type-specific markers was determined by RT-qPCR and immunostaining. Tumorigenicity of enriched PrCSC was determined by soft agar assay and xenograft assay in NOD/SCID mice. Biopsy samples from 19 confirmed prostate cancer patients were used for establishing PPrCC, and 18 cases (95%) succeeded. Both basal marker (CK5) and luminal markers (androgen receptor and CK8) strongly co-expressed in most of PPrCC, indicating their basal epithelial origin. After amplification under adherent culture condition in vitro, transient amplifying cells were the dominant cells. Sphere formation efficiency (SFE) of passaged PPrCC was about 0.5%, which was 27 times lower than SFE of LNCaP (13.67%) in the same condition. Compared with adherent cells from PPrCC, prostasphere from PPrCC showed up regulated stem cell markers and increased tumorigenic potential in soft-agar assay. However, spheroid cells from PPrCC prostasphere failed to initiate tumor in xenograft assay in 6 months. Thus, PPrCC can be established and amplified from prostate cancer biopsy samples. Our modified sphere culture system can enrich PrCSC from PPrCC. 

Enrichment of prostate cancer stem cells from primary prostate cancer cultures of biopsy samples.

Prostate cancer is one of the most seriously malignant diseases threatening men's health, and the mechanisms of its initiation and progression are not yet completely understood. Recent years have witnessed distinct advances in researches on prostate cancer stem cells in many aspects using different sources of materials, such as human prostate cancer tissues, human prostate cancer cell lines, and mouse models of prostate cancer. Prostate cancer stem cell study offers a new insight into the mechanisms of the initiation and progression of prostate cancer and contributes positively to its treatment. This article presents an overview on the prostate cancer stem cell markers utilized in the isolation and identification of prostate cancer stem cells.

Shunqi Wang

Institute of Life Science,
School of Life Science

Nanchang University

The Cutting and Floating Method for Paraffin-embedded Tissue for Sectioning

Shunqi Wang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Institute of Life Science,School of Life Science

Nanchang University

The Cutting and Floating Method for Paraffin-embedded Tissue for Sectioning

Institute of Life Science,
School of Life Science