Inhibition of polyporus polysaccharide on proliferation of A549 cells by adjusting Cyclin D1 expression by HuR / 中草药

ABSTRACT

Objective: To study the effects of polyporus polysaccharide (PPS) on the proliferation of human lung cancer A549 cells and the corresponding molecular mechanism. Methods: The A549 cells in control group were normally treated and the cells in experimental groups were incubated with different doses of PPS. The MTT method and flow cytometry were used to analyze the influence of drugs on cell proliferation. The qRT-PCR was used to detect mRNA levels of A549 cells and Cyclin D1 mRNA stability. The levels of human antigen R (HuR) protein in plasma and nuclei and cyclin D1 protein were detected by Western blotting. Results: Compared with the control, the cell growth was obviously inhibited (P<0.05), the Cyclin D1 mRNA stability and Cyclin D1 mRNA were decreased in the mid-and high-dose PPS groups (P<0.05), the total protein of HuR was slightly changed, but the cytoplasm protein of HuR was down-regulated (P<0.05) and the nucleus protein of HuR was up-regulated (P<0.05). Conclusion: PPS can suppress the proliferation of A549 cells, which is possibly affected by down-regulating the cytoplasm protein of HuR, lowering the stability of Cyclin D1 mRNA, and thus decreasing the expression of Cyclin D1 protein.