title: IL-6 upregulation contributes to the reduction of miR-26a expression in hepatocellular carcinoma cells.
abstract: A recent study showed that miR-26a is downregulated in hepatocellular carcinoma tissues and that this downregulation is an independent predictor of survival. Interestingly, the same study also reported that miR-26a downregulation causes a concomitant elevation of IL-6 expression. Because miR-26a expression was found to be transcriptionally downregulated by oncogene c-Myc in various cancers, and the expression of c-Myc was increased by IL-6 stimulation, we hypothesized that IL-6 contributes to reduction of miR-26a in hepatocellular carcinoma. Serum IL-6 was measured by ELISA and miR-26a was detected by qRT-PCR. The data of 30 patients with hepatocellular carcinoma who had undergone surgical tumor resection revealed that serum IL-6 could be considered to be a predictor of survival up to 5 years for hepatocellular carcinoma patients (log-rank test, P < 0.05). We observed that the serum IL-6 concentration was inversely correlated with miR-26a expression in cancerous tissues (Pearson correlation test, r = -0.651, P < 0.01). Furthermore, by in vitro experiments with HepG2 cells, we showed that IL-6 stimulation can lead to miR-26a suppression via c-Myc activation, whereas in normal hepatocyte LO2 cells incubation with IL-6 had no significant effect on miR-26a expression. Taken together, these results indicate that miR-26a reduction in hepatocellular carcinoma might be due to IL-6 upregulation.
authors.affiliation: Department of Oncology, Wuhan General Hospital of Guangzhou Command, People’s Liberation Army, Wuhan, China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bicheng
authors.initials: B
authors.lastname: Zhang
authors.forename: Anran
authors.initials: A
authors.lastname: Zhang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jianfei
authors.initials: J
authors.lastname: Gao
authors.forename: Dianchun
authors.initials: D
authors.lastname: Fang
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Rao
mesh_terms: D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism*; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008875:Middle Aged; D012008:Recurrence; D015533:Transcriptional Activation / Q000235:genetics; D015854:Up-Regulation
chemical_list: D015850:Interleukin-6; D035683:MicroRNAs