Polo-like kinase 1 siRNA-607 induces mitotic arrest and apoptosis in human nasopharyngeal carcinoma cells

Abstract

Polo-like kinase (Plk) 1 is overexpressed in many human malignancies including nasopharyngeal carcinoma, indicating its potential as a therapeutic target. Recently, using a simple cellular morphologybased strategy, we have identified several novel effective siRNAs against Plk1 including Plk1 siRNA- 607. In this study, we further investigated the effects of Plk1 siRNA-607 in human nasopharyngeal carcinoma cell line, HNE-1. Real time RT-PCR and Western blot indicated that Plk1 siRNA-607 transfection resulted in a significant inhibition in Plk1 expression in the HNE-1 cells. Furthermore, cell cycle, cell growth and apoptosis analysis clearly indicated that Plk1 siRNA-607 caused a dramatic mitotic cell cycle arrest followed by massive apoptotic cell death, and eventually resulted in a significant decrease in growth and viability of the nasopharyngeal carcinoma cells. Given that Plk1 has been widely accepted as a novel efficient target for cancer therapy, these results suggested that Plk1 siRNA-607 could be further developed for the treatment of human nasopharyngeal carcinoma. Key words: Nasopharyngeal carcinoma, Plk1, RNA silencing, cell cycle, apoptosis.