Preliminary Study on Cancer Stem-like Cells in Human Breast Cancer Cell Iines

Background: With the development of tumor biology and animal cell culture technology, people gradually recognize the tumor cell population, there is a small part of the cell self-renewal, multi to differentiation and steady-state control characteristics, the root causes of tumor recurrence and metastasis cancer stem cell hypothesis, domestic and foreign scholars have done a lot of attempts Isolation and identification of cancer stem cells. Breast cancer is obviously malignant tumor heterogeneity is one of the most common malignancy in women, the experiment on different breast cancer cell lines of breast cancer stem cells subsets Isolation and identification of the nature of the preliminary study. Objective: by the breast cancer cell lines and stem cell subsets in cell culture, the chemotherapy drug intervention and flow cytometry screening and identification, explore the proportion of different breast cancer cell lines of CD44 CD24-/low cells, and enrichment of breast cancer stem cells Related Subsets methods. : 1 in cell culture, different biological characteristics of breast cancer cell line MCF-7 and MDA-MB-231, with or without TA chemotherapy (docetaxel and epirubicin) to observe the growth curve, to compare their growth; using flow cytometry two breast cancer cell lines the CD44 CD24-/low proportion of cells; 3. TA chemotherapy drug serum-free medium with or without added culture of these two breast cancer cell lines, to observe the formation of a ball of cells. 4 cell lines sensitive to chemotherapy drugs with two independent samples t-test, to P lt; 0.05 was considered statistically significant using SPSS13.0 statistical software to analyze data. : 1.MCF-7, MDA-MB-231 cell growth curve comparison: the first five days of the MCF-7 cells logarithmic growth phase, seven days a plateau; MDA-MB-231 cells 3 days logarithmic growth phase, eight days into the plateau. Prompted MDA-MB-231 cell doubling time is short, fast growth in MCF-7 cells, the biological behavior is poor. Comparison of the growth curve of the two cell lines after joining TA drug: the first day of the two cell lines the majority of cell death, the slow growth rate, and the next day MCF-7 cell growth rate gradually restored indirectly reflects the MCF-7 cell lines there may be some cells with chemotherapy resistance, self-renewal, to adapt to the new microenvironment. Sensitivity to chemotherapeutic drugs two independent samples t-test, MCF-7 cell system P gt; 0.05, no statistically significant, suggesting that the sensitivity of the program; MDA-MB-231 cell line P lt; 0.05, statistically significant, suggesting that MDA-MB-231 cell lines of the program sensitive to chemotherapy drugs. 3 serum-free suspension cultures of two breast cancer cell lines: MDA-MB-231 cell line most of the tumor cell death and found no significant cell ball; ball of cells MCF-7 cell line for the first time about the first six days of serum-free culture after tumor cell death. TA chemotherapy drug screening, see the two cell lines cell death, found no significant ball of cells. 4 flow cytometry proportion of breast cancer cell lines of CD44 CD24-/low cells: MCF-7 and MDA-MB-231 both cell lines phenotype CD44 CD24 subsets and CD44-CD24 sub-group, which the proportion of CD44 CD24-/low phenotype cells, respectively, 2.07% and 0.20%, respectively. Conclusion: the value-added of the 1.MDA-MB-231 cell line is faster, relatively high degree of malignancy, the TA chemotherapy drugs more sensitive than MCF-7 cell line MCF-7 cell line; after 2.TA drug intervention, inhibited rapid recovery of the growth rate, indirectly reflect the MCF-7 cell lines that may exist in a large proportion of cancer stem cells resist chemotherapy, self-renewal, to adapt to the new micro-environment; 3. serum-free culture medium of MCF-7 cell lines see suspended ball of cells formed, indicating that some cells can form cell clones with the characteristics of cancer stem cells; 4. flow cytometry, both cell lines although CD44 CD24-/low the phenotype of cells a small proportion, but in line with the current proportion of cancer stem cells reported in the literature: a very small amount of tumor cells act as stem cell role in tumor tissue; 5 CD44 CD24-/low by phenotype may not be breast cancer stem cells only specific surface markers, yet to be further research into tumor experiments in animals.