title: The p90rsk-mediated signaling of ethanol-induced cell proliferation in HepG2 cell line.
abstract: Ribosomal S6 kinase is a family of serine/threonine protein kinases involved in the regulation of cell viability. There are two subfamilies of ribosomal s6 kinase, (p90rsk, p70rsk). Especially, p90rsk is known to be an important downstream kinase of p44/42 MAPK. We investigated the role of p90rsk on ethanol-induced cell proliferation of HepG2 cells. HepG2 cells were treated with 10~50 mM of ethanol with or without ERK and p90rsk inhibitors. Cell viability was measured by MTT assay. The expression of pERK1, NHE1 was measured by Western blots. The phosphorylation of p90rsk was measured by ELISA kits. The expression of Bcl-2 was measured by qRT-PCR. When the cells were treated with 10~30 mM of ethanol for 24 hour, it showed significant increase in cell viability versus control group. Besides, 10~30 mM of ethanol induced increased expression of pERK1, p-p90rsk, NHE1 and Bcl-2. Moreover treatment of p90rsk inhibitor attenuated the ethanol-induced increase in cell viability and NHE1 and Bcl-2 expression. In summary, these results suggest that p90rsk, a downstream kinase of ERK, plays a stimulatory role on ethanol-induced hepatocellular carcinoma progression by activating anti-apoptotic factor Bcl-2 and NHE1 known to regulate cell survival.
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Jinhyung
authors.initials: J
authors.lastname: Bae
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Medicinal Plant Science, College of Science and Engineering, Jungwon University, Chungbuk 28024, Korea.
authors.forename: Young Sil
authors.initials: YS
authors.lastname: Min
authors.affiliation: Department of Pharmacology, College of Pharmacy, Catholic University of Daegu, Daegu 38430, Korea.
authors.forename: Hyun Dong
authors.initials: HD
authors.lastname: Je
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
authors.forename: Uy Dong
authors.initials: UD
authors.lastname: Sohn
keywords: Bcl-2; Ethanol; Hepatocellular carcinoma; NHE1; p90rsk