BnRCH gene inhibits cell growth of Hela cells through increasing the G2 phase of cell cycle.

The ubiquitin-proteasome pathway (UPP) is an important protein degradation system universally existing in eukaryotic organisms from yeast to human. In this system, hundreds of E3 ubiquitin-protein ligases are most important because they provide the substrate specificity and control many cellular processes. UPP has been found to be relevant to cancer development. BnRCH, the protein product from a novel gene isolated from Brassica napus, also has E3 ubiquitin-protein ligase activity. In order to exploit its potential use, human cervical carcinoma cell Hela (Hela cells) was transiently and stably transfected with BnRCH. The experimental results demonstrated: (1) in Hela cells, BnRCH inhibited the cell growth of Hela cells and increased their sensitivity to the anti-cancer chemotherapeutic drug cisplatin; and (2) the growth inhibition effect of BnRCH in Hela cells was found due to G2 phase cell cycle arrest with the transcriptional up-regulation of p21 (waf1/cip1), rather than apoptosis. This research suggests BnRCH has potential use in cancer therapy.