Inhibition effect of cyclinD1 on cell proliferation and transcription of cyclinE, CDK2 and p21~(cip1) in human breast cancer cell line

As comparing the cells in which cyclin D1 was inhibited with control cells, the cell proliferation reduced markedly, the radio of growth inhibition was about 54% at the sixth day in assay of cell growth. The changes of distribution of phases in cell cycle were observed. The proportion of cells in G1 phase increased while the proportion of cells in S and G2/M phase decreased. The levels of cyclinE and CDK2 mRNA fell to a certain extent and expression of p21~(cip1) did not show apparent change. The inhibition of cyclinD1 lessens abnormal cell proliferation of human breast cancer. The expressions of cyclinE and CDK2 as the genes in cell cycle control have close relationship with that of cyclinD1 while the expression of p21~(cip1) is not affected by cyclinD1.