Construction of Plasmid Expressing Cyclin E Antisense RNA in Eukaryotic Cell and Suppressive Role in the Growth of Human Breast Cancer Cells in vitro

Cyclin E plays an important role in control of the cell cycle.In order to study the function of cyclin E in human breast cancer,recombinant plasmid expressing cyclin E antisense RNA in eukaryotic cell was constructed and transfected to human breast cancer cell line Bcap\|37.The cell clones which contained the recombinant plasmid were selected by G418 and tested by PCR.Cyclin E expression of selected cell clones and control cells were tested by Western blot.The level of cyclin E protein decreased in the cell clones with recombinant plasmid.Then cell morphology,serum dependent growth and clonegenicity of cells in soft agar were analyzed.The results showed that cell size was enlarged due to inhibition of cyclin E,serum dependent growth was enhanced(cell number was about 1/5 of control cells on the sixth day in culture with low serum medium),and anchorage independent growth was decreased (ratio of clonogenicity decreased 57%).It indicated that the abnormal expression of cyclinE was related to malignant proliferation and anchorage independent growth of human breast cancer cells.