Expression Of CD133 And CD44 In Epithelial Ovarian Cancer And Research On Their Function

【Background and Objective】In the CSC model,only a small proportion of cells in the tumor are proposed to be able to proliferate and self-renew extensively, thus sustaining tumor growth.It is therefore intuitive that only the eradication of CSCs, now investigated as the target of novel strategies aimed at circumventing chemoresistance and radioresistance,can lead to an effective cancer cure.Ovarian cancer is the first leading cause of death in malignant tumor of female reproductive system.It is imperative to investigate effective treatment for ovarian cancer.The theory of CSC breaks a new path for the early diagnosis and novel therapeutic procedures of ovarian cancer.The key point of isolation of CSC is to seak suitable cell surface markers.The aims of this study are to detect the expression of CD133 and CD44 in epithelial ovarian cancer and their effect on self-renewal,differentiation and proliferation of cell.【Methods】1.Tumor tissue specimens were obtained at time of primary surgery from ovarian cancer patients in Qilu hospital.The cell lines we used include SKOV3,3AO, A2780 and OVCR3.2.The percentages of CD133 cells and CD44 cells in cell lines and primary cultured cells was detected by Flow Cytometry.3.Immunohistochemistry was use to detect the distributing of CD 133 and CD44 cells in clinical tissues.4.The CD133~+ cells were isolated from SKOV3 cells by MACS.5.The CD133~+ cells isolated from SKOV3 cells was cultured in cell culture fluid including 20%NBS.We determined the percentages of CD133 cells in isolated cells when 0,3 and 5 days after MACS.6.Statistical methods:The difference among multiple means was analyzed by One-Way ANOVA,and the difference between two means was analyzed by Independent-Samples T test,using SPSS 13.0 for Windows.In all statistical comparisons,a P vslue of＜0.05 was considered to be statistically significant.【Results】1.The primary cultured cells was flat and multangular in shape.With time passing,tumor cells increased in quantity.The time of cell passage was one week.2.Flow cytometry analysis of CD133 and CD44 cells The percentages of CD133 cells in SKOV3,A2780,3AO and OVCR3 respectively were 0.72%±0.10%,0.94%±0.22%,0.81%±0.50%and 0.77%±0.28%.The percentages of CD133 cells in 4 cell lines were not significantly different(P=0.85). The percentage of CD44 cells in SKOV3 was 96.92%±1.74%,while there were not CD44 cells in A2780,3AO and OVCR3.We determined the proportion of CD133 and CD44 cells in primary cultured cells in passageⅠandⅢ(from 12 patients).The percentage of CD133 cells in passageⅢcells was 1.27%±0.54%.The value of CD133 cells in passageⅠcells was 0.47%±0.13%.The values between them were significantly different(P=0.002); The percentage of CD133 cells in passageⅢcells was greater than that in SKOV3(P=0.046).The percentage of CD44 cells in passageⅢcells was 79.48%±13.21%.The value of CD133 cells in passageⅠcells was 93.42%±0.65%.The values between them were significantly different (P=0.049).The percentage of CD44 cells in passageⅢcells was less than that in SKOV3(P=0.002).3.Immunohistochemistry analysis of CD133 and CD44 cells CD133- expressing and CD44 -expressing cells distributed in all detected tissues,which are brown.4.Self-renewal,differentiation and proliferation capacity of CD133~+ cells The CD133~+ cells isolated from SKOV3 grew more fastly than CD133~-(data not shown).We determined the percentages of CD133 cells in isolated cells when 0,3 and 5 days after MACS.The values were 76.74%,11.91%,2.26%,which were downtrend.【Conclusion】1.Our study found that CD133 express in epithelial ovarian cancer cells(0.16%～2.05%).CD133~+ cells have the capacity of self-renewal,differentiation and proliferation,which are the characteristics of CSC.Thus,CD133 could be a cell surface marker of CSC in epithelial ovarian cancer,which will provide fundamental basis for the isolation,culturing and identification of CSC in epithelial ovarian cancer.2.CD44 express in SKOV3 and primary cultured cells(66.37%～98.87%),and it doesn't express in A2780,3AO and OVCR3 cells.CSC is a small subset of cancer cells.So we think that CD44 is not the cell surface marker of CSC in epithelial ovarian cancer.