Background: Studies showed that aberrant activation of JAK/STAT3 signaling pathway promoted the tumorigenesis and progression of hepatocellular carcinoma (HCC), and transforming growth factor-β1 (TGF-β1) has either tumor-suppressing or tumor-promoting effect in regulation of tumor progression.Aims: To investigate the effect of specific inhibition of JAK/STAT3 signaling pathway on HCC and whether TGF-β1 signaling pathway is involved in this process or not.Methods: Thirty Wistar rats were randomly divided into three groups: control group, HCC group, and HCC+AG490 group.In the latter two groups, diethylnitrosamine was administered in drinking water to induce HCC model, and in HCC+AG490 group, AG490, a specific inhibitor of JAK was injected intraperitoneally in the first week of model establishment.At the end of the 16th week, all rats were sacrificed.The maximum diameter of tumor nodules in the liver was recorded and the number of tumors with maximum diameter greater than 1 cm was counted.Expression and distribution of STAT3 and TGF-β1 in liver tissue were determined by real-time PCR, immunohistochemistry, and immunofluorescence.Results: Compared with the control group, expressions of STAT3 and TGF-β1 mRNA in liver tissue were significantly increased in HCC group (P<0.05).Phosphorylated STAT3 (p-STAT3) and TGF-β1 proteins were absent in liver tissue in control group, and both were up-regulated and co-expressed in HCC group.While in HCC+AG490 group, expressions of STAT3 and TGF-β1 mRNA were significantly lower than those in HCC group (P<0.05);the liver tissue was weakly positive for p-STAT3 and TGF-β1 proteins, and the number of tumor nodules greater than 1 cm and the maximum diameter were markedly reduced when compared with the HCC group [1.20±1.03 and (1.14±0.18) cm vs.4.30±1.06 and (1.78±0.27) cm, P all<0.05].Conclusions: Specific inhibition of JAK/STAT3 signaling pathway may restrain the tumorigenesis and progression of HCC partially by interfering TGF-β1 signaling pathway.%背景:研究表明,异常激活的JAK/STAT3信号通路可促进肝细胞癌(HCC)发生、发展;转化生长因子-β1(TGF-β1)在肿瘤进展中发挥双向调节作用.目的:探讨特异性抑制JAK/STAT3信号通路对HCC的影响以及TGF-β1信号通路在其中的可能作用.方法:30只Wistar大鼠随机分为对照组、HCC组和HCC+AG490组,后两组以二乙基亚硝胺制作HCC模型,HCC+AG490组造模第1周腹腔内注射JAK特异性抑制剂AG490.第16周末处死大鼠,记录肝内肿瘤结节的最大直径,计数最大直径>1 cm的肿瘤结节数,以real-time PCR、免疫组化和免疫荧光染色检测肝组织中STAT3、TGF-β1的表达和分布.结果:与对照组相比,HCC组肝组织中STAT3、TGF-β1 mRNA表达显著增高(P<0.05).磷酸化STAT3(p-STAT3)、TGF-β1蛋白在对照组肝组织中呈阴性表达,在HCC组则分别呈阳性和强阳性表达,且两者有明显的共表达区域.HCC+AG490组STAT3、TGF-β1 mRNA表达较HCC组显著降低(P<0.05),p-STAT3、TGF-β1蛋白呈弱阳性表达,直径>1 cm的肿瘤结节数和最大直径均显著小于HCC组[1.20±1.03和(1.14±0.18) cm 对4.30±1.06和(1.78±0.27) cm,P均<0.05].结论:特异性抑制JAK/STAT3信号通路可抑制HCC发生、发展,其机制可能与抑制TGF-β1信号通路有关.
展开▼
