title: Estrogen-related receptor γ is upregulated in liver cancer and its inhibition suppresses liver cancer cell proliferation via induction of p21 and p27.
abstract: Orphan nuclear receptor estrogen-related receptor γ (ERRγ) regulates cell growth and tumorigenesis in various cancers. However, the clinical relevance of ERRγ to hepatocellular carcinoma (HCC) remains unclear. Here we examined the clinical significance of ERRγ in HCC and its potential as a therapeutic target. ERRγ levels in tissues from completely resected specimens from 190 HCC patients were examined immunohistochemically and their association with clinical stage and pathological grade was analyzed. Small interfering RNA (siRNA)-mediated knockdown of ERRγ (siRNA-ERRγ) or an ERRγ inverse agonist, GSK5182, were also used to examine the effects of ERRγ inhibition on the proliferation and growth of a human hepatoma cell line, PLC/PRF/5. Immunohistochemical analysis revealed that tumor tissues showed higher levels of ERRγ-positivity than adjacent non-tumor lesions. Tumors showing high levels of ERRγ immunoreactivity also had advanced tumor node metastasis (TNM) and Barcelona Clinic Liver Cancer stages and a higher Edmondson-Steiner grade. In addition, high-level expression of ERRγ in tumors of advanced TNM stage correlated with poorer overall survival. Treatment of PLC/PRF/5 cells with siRNA-ERRγ or GSK5182 inhibited proliferation through G1 arrest, increased expression of p21 and p27 and decreased expression of phosphorylated retinoblastoma protein. GSK5182-induced reactive oxygen species also suppressed the proliferation of PLC/PRF/5 cells. The present study showed that ERRγ expression is clinically significant in HCC; therefore, it can be considered a biomarker for HCC diagnosis. Moreover, the results provide a rationale for the use of ERRγ inhibitors such as GSK5182 as potential therapeutic agents.
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Republic of Korea.|Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu, Republic of Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Republic of Korea.|Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Yeon-Kyung
authors.initials: YK
authors.lastname: Choi
authors.affiliation: Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Jun-Kyu
authors.initials: JK
authors.lastname: Byun
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: Yu Na
authors.initials: YN
authors.lastname: Kang
authors.affiliation: New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea.
authors.forename: Seong Heon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: Byoung Kuk
authors.initials: BK
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Republic of Korea.|Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu, Republic of Korea.|Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Keun-Gyu
authors.initials: KG
authors.lastname: Park
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics* / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics* / Q000378:metabolism; D005500:Follow-Up Studies; D059585:G1 Phase Cell Cycle Checkpoints / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics*; D015854:Up-Regulation
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; C490917:ESRRG protein, human; D017382:Reactive Oxygen Species; D011960:Receptors, Estrogen; D050760:Cyclin-Dependent Kinase Inhibitor p27