2型糖尿病合并慢乙肝人群HBV/S基因变异与肝硬化/肝癌关系的研究

It has been reported that there is an increased risk of liver cirrhosis/carcinoma in type 2 diabetes mellitus patients with chronic hepatitis B (T2D-CHB). Our recent study firstly reported that hepatitis B virus (HBV) S gene variation was significantly higher in T2D-CHB patients compared to those in CHB patients without diabetes mellitus. The further analysis showed that the HBV/S gene has the complementary sequence of miR-183, which indicates that S gene mRNA can sequester miR-183 and inhibit its promoting ability of cancer development. Moreover, our results revealed that the mutations of the miR-183-seed complementary (miR-183-SC) sequences in T2D-CHB patients with liver cirrhosis/cancer were more frequently than those in T2D-CHB patients without liver cirrhosis/cancer. However, the associations between the increased variation in “miR-183-SC region” of S gene and the risks of T2D-CHB related liver cirrhosis/cancer remain unclear. In the present program, we will perform a prospective cohort study to analyze the associations of “miR-183-SC region” variation with liver cirrhosis/carcinoma in T2D-CHB patients, and the interaction effects between “miR-183-SC region” variation and traditional risk factors on the liver cirrhosis/carcinoma development in T2D-CHB patients. Based on these findings, we will construct the prediction model for the prediction of liver cirrhosis/carcinoma in T2D-CHB and evaluate its application value. At last, we will perform a cellular study and a tumor implantations experiment to further validate the associations between “miR-183-SC region” variation and liver cirrhosis/carcinoma. Thus, the results of our present program should be very important for the further researches on the etiology and the precise prevention strategy of liver cirrhosis/carcinoma development in T2D-CHB patients.

2型糖尿病合并慢乙肝人群（T2D-CHB）肝硬化/肝癌的发生风险显著升高。我们前期研究首次表明T2D-CHB人群HBV/S基因变异增加。进一步分析显示S基因含有miR-183（促癌功能）的互补序列，合并肝硬化/肝癌的T2D-CHB患者中S基因miR-183种子序列互补区（miR-183-SC区）的突变显著增加。然而，对于miR-183-SC区变异能否促进T2D-CHB疾病的恶性化进程目前仍不清楚。本项目通过对T2D-CHB人群开展前瞻性队列研究，进一步明确S基因miR-183-SC区变异与肝硬化/肝癌的关联关系；探索miR-183-SC区变异与传统危险因素对肝硬化/肝癌的交互作用；构建T2D-CHB肝硬化/肝癌的风险预测模型并进行评价；最后通过细胞和裸鼠成瘤实验验证人群中的研究结果。研究结果对于T2D-CHB肝硬化/肝癌的关键病因学机制研究和精准的预防策略研究都具有十分重要的意义。

2型糖尿病合并慢乙肝人群（T2D-CHB）肝硬化/肝癌的发生风险显著升高。本项目的主要研究内容是探索T2D-CHB人群HBV/S基因变异特征、具有促癌功能的循环miR-183及其在HBV/S基因序列互补区（miR-183-SC）的变异能否促进疾病的恶性化进程。研究发现，T2D-CHB患者HBV/S区的核苷酸变异率显著高于非糖尿病CHB患者（86.00% vs 70.17%, P=0.025）。将基线循环miR-183水平依据中位数分为两组，与低表达循环miR-183水平（log2-△CT）（< 3.15）的研究对象相比，在调整混杂因素后，高表达循环miR-183（≥3.15）的T2D-CHB患者发生肝硬化的风险升高1.65倍（RR=1.65，95% CI=1.07~2.55，P=0.023）。ROC分析结果表明，循环miR-183作为标志物预测T2D-CHB患者肝硬化发生风险的曲线下面积可达到0.75，灵敏度和特异度可达0.67和0.79。对miR-183-SC区是否变异与肝硬化发生风险的研究结果显示，在调整了混杂因素后，发生miR-183-SC区变异的T2D-CHB患者发生肝硬化的风险是未发生miR-183-SC区变异的2.47倍（RR=2.47，95%CI=1.15~5.50，P=0.027），miR-183-SC区变异的位点主要发生在nt561位且主要表现为G/C突变（94.8%）。但是ROC分析结果显示，miR-183-SC区变异结合传统危险因素构建的风险模型预测T2D-CHB患者肝硬化发生风险的曲线下面积仅为0.592，灵敏度和特异度仅为0.571和0.594。与野生型毒株相比，miR-183-SC区发生G/C突变的HBV毒株的复制和增殖能力约增加1.35倍，但是该突变对于肿瘤细胞浸润和侵袭能力无明显影响。综上所述，T2D-CHB患者体内HBV/S基因核苷酸水平突变较非糖尿病CHB患者频繁，HBV/S基因miR-183-SC区变异毒株的复制增殖能力增强且与T2D-CHB患者发生肝硬化风险关联；此外，T2D-CHB患者循环miR-183水平升高预示肝硬化发生风险增加。研究结果为T2D-CHB肝硬化/肝癌的预防和控制提供了新的重要的公共卫生学依据。