Kanda Mitsuro, Sugimoto Hiroyuki, Nomoto Shuji, Oya Hisaharu, Hibino Soki, Shimizu Dai, Takami Hideki, Hashimoto Ryoji, Okamura Yukiyasu, Yamada Suguru, Fujii Tsutomu, Nakayama Goro, Koike Masahiko, Fujiwara Michitaka, Kodera Yasuhiro
Department of Gastroenterological Surgery (Surgery Ⅱ), Nagoya University Graduate School of Medicine, Nagoya, Aichi 466‑8550, Japan.
Division of Hepato‑Biliary‑Pancreatic Surgery, Shizuoka Cancer Center, Shizuoka 411‑8777, Japan.
Int J Oncol. 2015 Feb;46(2):641-8. doi: 10.3892/ijo.2014.2762. Epub 2014 Nov 18.
Although the B‑cell translocation gene 1 (BTG1) plays an important role in apoptosis and negatively regulates cell proliferation, BTG1 expression in hepatocellular carcinoma (HCC) has not been evaluated. In this study expression analysis of BTG1 was conducted to clarify the role of BTG1 in the initiation of HCC carcinogenesis and progression. BTG1 mRNA expression levels were determined for HCC cell lines and 151 surgical specimen pairs using quantitative real‑time reverse transcription polymerase chain reaction (RT‑qPCR) assay. The mutational and methylation status of HCC cell lines were analyzed via high resolution melting (HRM) analysis and direct sequencing analysis to elucidate the regulatory mechanisms of BTG1 expression. The expression and distribution of the BTG1 protein in liver tissues were evaluated using immunohistochemistry (IHC). Decreased expression of BTG1 mRNA was confirmed in the majority of HCC cell lines (89%) and clinical HCC tissues (85%) compared with non‑cancerous liver tissues. Mutations or promoter hypermethylation were not identified in HCC cell lines. BTG1 mRNA expression levels were not influenced by background liver status. The pattern of BTG1 protein expression was consistent with that of BTG1 mRNA. Downregulation of BTG1 mRNA in HCC was significantly associated with shorter disease‑specific and recurrence‑free survival rates. Multivariate analysis of disease‑specific survival rates identified BTG1 mRNA downregulation as an independent prognostic factor for HCC (hazard ratio 2.12, 95% confidence interval 1.12‑4.04, P=0.022). Our results indicate that altered BTG1 expression might affect hepatocarcinogenesis and may represent a novel biomarker for HCC carcinogenesis and progression.
尽管B细胞易位基因1（BTG1）在细胞凋亡中发挥重要作用并对细胞增殖起负调控作用，但尚未对其在肝细胞癌（HCC）中的表达进行评估。在本研究中，进行了BTG1的表达分析，以阐明BTG1在HCC发生起始和进展中的作用。使用定量实时逆转录聚合酶链反应（RT-qPCR）检测法测定了HCC细胞系和151对手术标本中BTG1 mRNA的表达水平。通过高分辨率熔解（HRM）分析和直接测序分析，分析了HCC细胞系中BTG1的突变和甲基化状态，以阐明BTG1表达的调控机制。使用免疫组织化学（IHC）评估BTG1蛋白在肝组织中的表达和分布。与癌旁肝组织相比，大多数HCC细胞系（89%）和临床HCC组织（85%）中均证实BTG1 mRNA表达降低。在HCC细胞系中未发现突变或启动子高甲基化。BTG1 mRNA表达水平不受背景肝脏状态的影响。BTG1蛋白的表达模式与BTG1 mRNA一致。HCC中BTG1 mRNA的下调与较短的疾病特异性生存率和无复发生存率显著相关。对疾病特异性生存率的多变量分析确定BTG1 mRNA下调是HCC的独立预后因素（风险比2.12，95%置信区间1.12-4.04，P=0.022）。我们的结果表明，BTG1表达改变可能影响肝癌发生，可能代表HCC发生和进展的一种新型生物标志物。
