Effect of silencing cyclin D1 gene on chemotherapeutic drug sensitivity in K562 cells in vitro / 肿瘤研究与临床

ABSTRACT

Objective Cyclin D1 gene plays a significant role in regulating cell cycle progression.It is reported that over-expression of cyclin D1 gene is intimately associated with origination,development and prognosis of tumor and is associated with tumor cells resistance to chemotherapy drug.Suppression of cyclin D1 protein expression leads to cellular chemosensitization.This study was to determine whether this effect also existed in chronic leukemia cell line K562 by inhibiting the expression of cyclin D1 protein through RNA interference.Methods Plasmid vectors expressing small hairpin RNA (shRNA) targeting at cyclin D1 gene were constructed and transfected into K562 cells by chitosan.Cyclin D1 protein was examined using Western Blotting analysis.The cell cycle and apoptosis were determined by flow cytometry.Cellular chemosensitization was evaluated by MTY assay.Results Expression of cyclin D1 protein was markedly down-regulated after transfection with pshRNA-419 and pshRNA-575 at 48 h.Down-regulation of cyclin D1 protein could affect the redistribution of cell cycle,induce apoptosis of K562 cells,decrease 50％inhibitoryconcentration (IC50) of adriamycin and enhance cellular chemosensitization.But there had no above biological effects observed after transfection with blank vector and control vector of m-pshRNA-790 at 48 h.ConclusionK562 cells could be chemosensitized by the down-regulation of cyclin D1 expression through RNA interference.