Increasing evidence suggests that many types of cancers contain a population of cells that display stem cell properties. These cells are called cancer stem cells （CSCs），which are closely related to tumor initiation，growth，metastasis and chemoresistance. CSCs are also found in esophageal squamous cell carcinoma （ESCC）. These cells are characterized by potential of self-renewal and differentiation，tumor formation in nude mice and chemotherapy resistance，and thus may play an important role in targeted cancer therapies. Current methods for culturing and sorting CSCs in ESCC mainly include fluorescence activated cell sorting （FACS），magnetic activated cell sorting （MACS），suspension culture，and side population （SP） cell sorting. In this review，we focus on current research methods for CSCs in ESCC，their biological characteristics and areas for improvement. We believe that a combination of multiple cell-surface makers is needed for research of CSCs in ESCC.
Objective To analyze the advances of cancer stem cell (CSC) in recent years, and to propose a prospect for CSC research and cancer therapy. Methods Articles about important advances of CSC theory and cancer therapy were reviewed, and then selected and summarized. Results In 2001, CSC was first put forward as a concept, till now, which has been confirmed in many tissues. In recent years, efforts were dedicated to such topics including: identification of CSC in sol id tumors, the origin of CSC, its niche and growth mechanism, cancer therapy, etc. According to the CSC theory, traditional therapeutic methods have deficiencies, and new treatment targeting CSC may thoroughly el iminate tumors. Conclusion At present, CSC theory is still controversial, while it proposed revolutionary methods and directions for the therapy of cancer.
ObjectiveTo summarize the role of epithelial-mesenchymal-transition （EMT） in occurrence and development of gastrointestinal cancer. MethodsDomestic and international publications online involving EMT of gastrointestinal cancer in recent years were collected and reviewed. ResultsEMT was a highly conserved process that has been well characterised in embryogenesis. Studies had shown that the aberrant activation of EMT in adult epithelia could promote tumour metastasis by repressing cell adhesion molecules. E-cadherin， one of the epithelial cell markers, maybe involved in the process of the EMT, especially of the Ecadherin transcriptional repressors， these transcriptional repressors significantly increased in the gastrointestinal cancer. Further more， EMT might involve in the process of gastrointestinal cancer stem cells formation. ConclusionsEMT and it’s regulators play a very important role in gastrointestinal cancer， and may provide a newsight into the gastrointestinal cancer. It also can provide a novel clinical targets to treat the gastrointestinal cancer.
Objective To summarize the advancement of breast cancer stem cells and genotyping and analyze the correlation between the two. Methods Relevant literatures about breast cancer stem cells and genotyping, which were published recently were collected and reviewed. Results Cancer stem cell origin theory was supported by researches of correlation between breast cancer stem cells and genotyping, which also explained the complexity of intrinsic subtypes and heterogeneity of breast cancer. Conclusions A new way can be detected to study the formation mechanism and biological characteristics of breast cancer at the cellular and molecular level by researches of correlation between breast cancer stem cells and genotyping, which are expected to provide new strategies and tools for diagnosis and treatment of breast cancer.
ObjectiveTo investigate the expression and clinical significance of octamer-binding transcription factor 4(Oct-4) in gastric cancer (GC) tissues with meta-analysis. MethodsPubMed, EMBASE, Web of Science, CBM, VIP, CNKI, and WanFang Database were searched from their establishment to Oct.2012 for related studies, to investigate the relationship between expression of Oct-4 and the clinicopathological characteristics of GC.After evaluating methodo-logical quality of studies that met the inclusion criteria, RevMan 5.1 software was used to data analysis. ResultsEight studies which enrolled 623 cases of GC were identified.The results of the meta-analysis showed that, as for the positive expression rate of Oct-4, there were significant differences between GC tissues and normal stomach tissues (OR=37.50, 95% CI: 4.76-295.51, P < 0.01), as well as the cell differentiation (OR=0.27, 95% CI: 0.16-0.45, P < 0.01), for that the positive expression rate of Oct-4 in low differentiation of gastric cancer tissues was higher than those of moderate-high differentation group.But there were no significant differences between GC tissues with lymph node metastasis and non-lymph node metastasis (OR=2.09, 95% CI: 0.63-6.94, P=0.23), as well as Ⅰ-Ⅱ stage and Ⅲ-Ⅳ stage (OR=0.62, 95% CI: 0.25-1.54, P=0.30) of GC tissues. ConclusionsOct-4 may participate in the whole course of carcinogenesis of GC, but the relationship between expression of Oct-4 and lymph node metastasis as well as the TNM stage of GC is unclear, which needs more high quality studies to explore the question clearly.
ObjectiveTo explore and hypothesize the potential mechanisms of cancer stem cell(CSC) in peritoneal metastasis of gastric cancer. MethodsThe databases of PubMed and CNKI were searched, and relevant literatures were reviewed to draw out systematic hypotheses. ResultsMetastatic cancer stem cell(MCSC) was the subpopulation of CSC with the capacity of metastasis, had still not been well investigated. MCSC transfer was the tendency of migration and planting to specific target tissue by multi-steps of "homing" process. Peritoneal metastasis of gastric cancer was a simplified "homing" process, and we thinked that the key steps were adhesion, migration, and niche establishment of MCSC in peritoneum. That capturing human MCSC of peritoneal metastases in gastric cancer and identifying its stemness feature to determine high tumorigenicity and high invasive ability of it were the important research fields. ConclusionMCSC might play certain role in multiple processes in peritoneal metastasis of gastric cancer, but currently it's lack of relevant researches.
ObjectiveTo isolate cancer stem cells (CST) from human breast cancer cell line (MCF-7) and study their sensitivity toward oxidative stress.MethodsMCF-7 cells were cultured in serum-free suspension culture medium to identify cells forming the sphere phenotype. The morphological changes of MCF-7 cells were observed by inverted phase contrast microscope (compared with MCF-7 cells cultured in serum-free suspension culture medium). The expression of CST marker CD133 was detected by immunocytochemical staining in CST cell spheres (experimental group) with a diameter of 100 μm and MCF-7 cells (control group) with a fusion degree of 70%. The positive rate of CD133 was detected by flow cytometry in the third generation of tumor cells with diameter of 150 μm. The second generation of tumor globular cells (experimental group) with diameter of 150 μm and corresponding MCF-7 cells (control group) were taken to be damaged by 50 mol/L H2O2 for 120 minutes. The expression of DNA damage marker histone H2AX phosphorylation (γH2AX) was detected by immunocytochemical staining.ResultsInverted phase contrast microscopy showed that MCF-7 cells grew initially in a single-cell adherent state, then aggregated and grew in serum-free suspension culture medium, and finally formed CST cell spheres, while the control MCF-7 cells cultured in MCF-7 cell culture medium grew extensively and could not grow in suspension. Fluorescence microscopy showed that the expression of CD133 in MCF-7 cells of control group was negative, while that in experimental group was positive. Flow cytometry showed that CD133 was positive in CST cells, and the positive rate was 92%. Inverted fluorescence microscopy showed that the expression of γH2AX in CST tumor spheres of experimental group was significantly lower than that in MCF-7 cells of control group after 120 minutes of H2O2 injury.ConclusionSerum-free suspension culture medium can produce globular CST cells from MCF-7 tumor cell line, which have strong antioxidant damage.