siRNA-mediated CDK6 knockdown suppresses nasopharyngeal carcinoma cell growth and cell cycle transition in vitro / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To assess the effect of small interfering RNA (siRNA)-mediated suppression of CDK6 expression on the proliferation and cell cycles of nasopharyngeal carcinoma (NPC) cells in vitro.</p><p><b>METHODS</b>QRT-PCR was used to examine the differential expression of CDK6 in 30 NPC tissues and 18 normal nasopharyngeal tissues. A siRNA targeting CDK6 was transfected in NPC CNE2 cells, and MTT assay and flow cytometry were used to analyze the changes in cell proliferation and cell cycle distribution. Western blotting was used to examine the expressions of the cell cycle-related factors.</p><p><b>RESULTS</b>Compared with normal nasopharyngeal tissues, NPC tissues showed an increased expression of CDK6 mRNA. Knocking down CDK6 expression obviously inhibited tumor cell growth and cell cycle transition from G1 to S phase and caused reduced expressions of CDK4, CCND1, and E2F1 and enhanced expression of the tumor suppressor p21.</p><p><b>CONCLUSION</b>NPC tissues overexpress CDK6. Knocking down CDK6 expression inhibits the growth and cell cycle transition of NPC cells in vitro by inhibiting the expressions of CDK4, CCND1, and E2F1 and upregulating tumor suppressor p21 expression.</p>