RESUMO
Objective To investigate the effects of leptin on proliferation of the breast carcinoma MCF-7 cells in terms of protein and nRNA of Rab-25 and C-myc.Methods MCF-7 cells were treated with leptin and normal saline (NS) as control.The 490 nm OD values of cells were read by MTT and the protein and mRNA expressions of Rab-25 and C-myc were measured by western blot and RT-PCR methods in two groups.Results Compared with control group,leptin can promote the proliferation of MCF-7 cells in a dose and time dependent manner within certain limit and up-regulate the protein expressions of Rab-25 and C-myc in the breast carcinoma MCF-7 cells (P ＜ 0.05).However,leptin also can up-regulate the mRNA expressions of Rab-25 but without significance (P =0.05).On the contrary,leptin can also up-regulate the mRNA expressions of C-myc (P ＜ 0.05).Conclusion Leptin promotes breast cancer cells proliferation,which may be related to up-regulate the protein and mRNA expressions of Rab-25 and C-myc.It could provide theoretical foundation and new target of gene therapy in the clinical treatment of breast cancer.
RESUMO
To study the anti-tumor activity of Scurrula parasitica polysaccharides (SP). Water extraction and ethanol precipitation were used to isolate SP from S. parasitica leaf. S180, K562 and HL-60 cell lines proliferation inhibition by SP were detected by MTT assay. The expressions of Ki-67, Cyclin D1, Bax and Bcl-2 protein in the sarcoma S180 tissues were detected by immunohistochemistry technique to approach the anti-tumor mechanism of SP+ SP could not inhibit cancer cell proliferation. SP ip could inhibit the growth of sarcoma S180 in mice, 100 mg x kg(-1) x d(-1). SP ip was the optimal dose on inhibiting S180 growth, with the tumor inhibition rate of 54%. The expression of Ki-67, Cyclin D1, Bax and Bcl-2 protein in the sarcoma S180 tissues were detected by immunohistochemistry technique to approach the anti-tumor mechanism of SP. The result showed that SP could down-regulate the expression of Ki-67, CyclinD1 and Bcl-2 protein, and up-regulate the expression of Bax protein. It indicted that inhibiting cancer cell proliferation and promoting cancer cell apoptosis in vivo maybe one of the anti-cancer mechanisms of SP.