Abstract:

Objective   To isolate side population(SP)cells from human ovarian epithelial cancer OVCAR3 cells and to study their tumorigenicity and invasion．  Methods  Flow cytometry and Hoechst 33342 dye efflux assay were used to isolate SP cells and non-SP cells from the OVCAR3 cell line of human ovarian epithelial carcinoma．Tumorigenicity of the two subpopulations was observed by a soft agar cloning method and sphere-forming assay． Invasiveness was measured by a Transwell experiment.  Results  The proportion of SP cells excluding Hoechst 33342 dye in the OVCAR3 cells was 13.1％, by addition of verapamil, it was 1.8%, which was greatlydecreased. CFE of SP and non-SP was 46.17％±23.27％ and 6.17％±3.06％，respectively(P<0.05). SP cells formed cell spheres in serum-free culture, but non-SP cells  did not. The cell number that infiltrated the Transwell membrane in the SP group(215.9±30.9) was significantly higher than that in the non-SP group (60.9±10.5)．  Conclusion  Human epithelial ovarian carcinoma cell line OVCAR3 contains a small subpopulation of cells excluding Hoechst 33342 dye that exhibits high tumorigenicity and invasion potential，indicating that SP cells have played a principal role in ovarian carcinoma cell proliferation and invasiveness．

Key words: Ovarian neoplasms； Tumor stem cells； Side population cell； Neoplasm invasion