假基因HMGB1P5调控PFKFB3促进糖酵解增强胆囊癌耐药的机制研究

Drug resistance is the leading cause of the poor prognosis for gallbladder cancer. Our previous study found that drug efflux protein (MDR1 and MRP1) and anti-apoptotic protein (Mcl-1 and Bcl-2), the important contributors to chemoresistance in gallbladder cancer, are also closely associated with glycolysis. Study of pseudogene in cancer has become to a focus recently. Our preliminary investigation showed for the first time that the pseudogene, HMGB1P5, through increasing PFKFB3 expression, which is the key kinase of the glycolytic pathway, promoted glycolysis and chemoresistance of gallbladder cancer. A common miR-142 binding site was found in HMGB1P5, HMGB1, and PFKFB3, suggesting that competitive endogenous RNA mechanism may be exited among HMGB1P5, HMGB1, PFKFB3 and miR-142. In this study, we will further analysis the ceRNA regulation mechanism existed among pseudogenes HMGB1P5, HMGB1, PFKFB3, and miR-142, and followed by revealing how they finally led to increased chemoresistance in gallbladder cancer cells. Elevating pseudogenes HMGB1P5 expression in gallbladder cancer cells increased PFKFB3 expression and then activated glycolysis followed by decreasing ROS levels and increasing ATP supply rate. While lower ROS levels could inhibit oxidative stress and cell apoptosis, higher ATP supply rate enhanced the drug effluxing efficiency of drug efflux proteins, which ultimately enhanced chemoresistance of gallbladder cancer. In addition, we will also investigate HMGB1P5 and PFKFB3 whether can be molecular diagnostic markers of chemosensitivity and treatment targets for gallbladder cancer.

胆囊癌细胞耐药性强是其疗效差的重要原因。我们前期研究发现药泵蛋白（MDR1及MRP1）和抗凋亡蛋白（Mcl-1及Bcl-2）高表达是胆囊癌耐药的关键因素，且与肿瘤细胞糖酵解效应增强密切相关。假基因目前已成为肿瘤研究的热点。本研究预实验首次发现胆囊癌细胞内假基因HMGB1P5能调控糖酵解关键酶PFKFB3的表达，增强糖酵解效应，进而促进胆囊癌耐药。并首次揭示HMGB1P5、HMGB1及PFKFB3之间存在共同的miR-142作用位点，提示它们之间可能存在ceRNA调控机制。本研究拟解析HMGB1P5调控PFKFB3的ceRNA机制，首次提出HMGB1P5表达↑→PFKFB3表达↑→糖酵解水平↑→ROS↓，ATP生成速率↑→氧化应激↓，药泵蛋白活力↑→抗凋亡能力↑，化疗药物泵出速度↑→胆囊癌细胞耐药的信号转导路径，并探讨HMGB1P5及PFKFB3作为胆囊癌化疗敏感性标志物及治疗靶点的可行性。

胆囊癌是胆道系统最为常见的恶性肿瘤，占同期胆道疾病的0.4%~3.8%。以吉西他滨为基础联合铂类药物化疗是晚期胆囊癌患者的标准治疗方案，但大多数患者都具有耐药性。因此，胆囊癌细胞耐药性强是其疗效差的重要原因。本研究预实验首先发现胆囊癌细胞内假基因HMGB1P5能调控糖酵解关键酶PFKFB3的表达，增强糖酵解效应来促进胆囊癌细胞耐药性的产生。我们进一步研究发现HMGB1P5通过miR-142来促进PFKFB3的表达，进而调控糖酵解及及氧化应激，最终通过药泵蛋白ABCG2来促进化疗药物泵出速度，导致胆囊癌细胞耐药的信号转导路径。本研究无论是对于鉴定新型胆囊癌耐药相关分子标志物，还是对于寻找新型靶向药物以提高胆囊癌患者的化疗敏感性，改善胆囊癌患者的预后都具有十分重要的推动作用。