title: RMP plays distinct roles in the proliferation of hepatocellular carcinoma cells and normal hepatic cells.
abstract: RMP has been shown to function in the transcription regulation through association with RNA polymerase (RNAP) II subunit RPB5. It also has been shown to be required for the proliferation of hepatocellular carcinoma (HCC) cells with an antiapoptotic property. In this article, we further demonstrate that RMP displays distinct features in HCC cells compared with normal hepatic cells. RMP expression is remarkably increased in various cancer cell lines including HCC cells when compared with normal cells. Depletion of RMP could inhibit the proliferation of HCC cells, but not the normal hepatic cells. RMP significantly prevented apoptosis of HCC cells in SMMC-7721 and HepG2, but had little effect on apoptosis in the normal hepatic cells. The mechanisms of RMP's distinct features rely on different responsive expressions of apoptosis factors induced by RMP in HCC and hepatic cells. Either overexpression or depletion of RMP significantly affected the expression of apoptosis factors in HCC cells. However, normal hepatic cells showed a tendency to resist RMP for the regulation of apoptosis. In the clinical samples, the increased expression of RMP in HCCs was also observed when compared with the matched non-tumor tissues from 30 HCC patients. The different expression levels of and distinct responses to RMP between HCC and hepatic cells suggest that RMP might serve as not only a biomarker for the diagnosis of HCC, but also a potential target for the HCC therapy.
authors.affiliation: Department of Cell Biology, School of Medicine, Soochow University, Suzhou, 215123 China.
authors.forename: Sijun
authors.initials: S
authors.lastname: Yang
authors.forename: Hongmin
authors.initials: H
authors.lastname: Wang
authors.forename: Yunlan
authors.initials: Y
authors.lastname: Guo
authors.forename: Shaomu
authors.initials: S
authors.lastname: Chen
authors.forename: Mei-Yin
authors.initials: MY
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Shen
authors.forename: Huijun
authors.initials: H
authors.lastname: Yu
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Miao
authors.forename: Hui-Yun
authors.initials: HY
authors.lastname: Wang
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Wei
mesh_terms: D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D017931:DNA Primers; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D008099:Liver / Q000166:cytology*; D008113:Liver Neoplasms / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins; D014407:Tumor Cells, Cultured
chemical_list: D017931:DNA Primers; D047908:Intracellular Signaling Peptides and Proteins; D012097:Repressor Proteins; C117184:URI1 protein, human
keywords: RMP; hepatocellular carcinoma cells