HMGB1在氯喹增强胃癌顺铂化疗敏感性的作用研究

Chemotherapy is a very importent method for the treatment of gastric cancer, but lots of patients suffer from tumor relapse or disease progression due to resistance to chemotheraputics.Recently, more and more reports have demonstrated that autophagy is closely associated with drug resistance, and it would be a promising therapeutic target for cancer treatment. In our previous studies, it's found that cisplatin could induce the activation of autophagy in gastric cancer cell SGC7901. After combination with choloquine, it's showed that autophagy was suppressed, the expression of MDR1 was down-regulated, and the anti-tumor activity of cispaltin was strengthened. Newly survey confirmed that the translocation of HMGB1 from nucleus to cytoplasm could cause the up-regualtion of autophagy. In our preliminary experiment, we also observed that positive expression of nucleus HMGB1 was a poor prognosis factor for patients with gastric cancer after operation. In addition, cisplatin could trigger the translocation of HMGB1 in SGC7901 cells, and the level of cytoplasm HMGB1 was decreased after pretreated with choloquine. Consequently, we speculate that the autophagy mediated by the release of HMGB1 play a key role in choloquine sensitizing gastric cancer cells to cisplatin. In this study, we will explore the effects of choloquine on gastric cancer cell autophagy, cisplatin sensitivity and cisplatin-related resistance protein in vitro and vivo experiments, and investigate the potential molecular mechanism by CRISPR/Cas9. We also evalute the value of HMGB1 in peripheral blood mononuclear cells for the dynamic monitoring of autophagy, and confirm its value in predicting of objective response to chemotherapy in gastric cancer. Ultimately, we would provide scientific and theoretical basis to the combined use of choloquine and cisplatin for the treatment of gastric cancer in clinic, and find a marker help to select patients who may be benefited from this method.

众多胃癌患者因化疗耐药导致疾病复发或进展。文献报道自噬可以促进肿瘤细胞耐药，而氯喹基于改变溶酶体pH值抑制自噬。新近证实HMGB1核-浆转移介导了骨肉瘤细胞自噬上调。我们的前期研究表明：核HMGB1是胃癌术后患者的不良预后因素，顺铂可导致胃癌胞浆HMGB1升高和自噬活性增强；联合氯喹后，自噬被抑制，且HMGB1和耐药基因MDR1表达下降，提高了顺铂的抗癌能力。因此我们推测：HMGB1释放介导的自噬在氯喹增强胃癌细胞对顺铂的化疗敏感性中起作用。本项目拟通过体内外实验明确氯喹对胃癌细胞自噬、顺铂化疗敏感性和铂耐药蛋白的影响，采用CRISPR/Cas9等技术初步探讨其分子机制；体内实验评价外周血单核细胞HMGB1动态监测自噬活性的价值；临床病例研究探讨监测外周血单核细胞HMGB1水平与变化预测晚期胃癌患者化疗客观疗效的作用，旨在为临床应用氯喹联合顺铂治疗胃癌以及患者的选择提供科学依据和理论基础。

众多胃癌患者因化疗耐药导致疾病复发或进展。文献报道自噬可以促进肿瘤细胞耐药，而氯喹基于改变溶酶体 pH 值抑制自噬。新近证实 HMGB1 核-浆转移介导了骨肉瘤细胞自噬上调。我们的前期研究表明：核 HMGB1 是胃癌术后患者的不良预后因素，顺铂可导致 胃癌胞浆 HMGB1 升高和自噬活性增强；联合氯喹后，自噬被抑制，且 HMGB1 和耐药基因 MDR1 表达下降，提高了顺铂的抗癌能力。因此我们推测：HMGB1 释放介导的自噬在氯喹增强胃癌 细胞对顺铂的化疗敏感性中起作用。本项目探讨了胃癌脑转移和胃癌骨转移患者的临床病理特征，分析了血清CEA和CA199变化对晚期胃癌一线姑息化疗的预测作用，采用免疫组化检测胃癌术后患者肿瘤组织HMGB1，为核表达，阳性率57.1%(24/42)；随访无病生存时间(DFS)，HMGB1(+)组、HMGB1(-)组DFS分别为29±3.3月和41±4.8月(P=0.006)。通过体内外实验明确了氯喹对胃癌细胞自噬、顺铂化疗敏感性和铂耐药蛋白的影响，采用CRISPR/Cas9 等技术初步探讨其分子机制，探讨了腹水脱落癌细胞Beclin-1 mRNA表达变化对顺铂腹腔化疗治疗胃癌恶性腹水疗效的预测作用。在国内外杂志发表学术论文4篇，有一定他人引用；获批中国实用新型专利1项；相关成果在省内多家医院推广应用，获2017年江西省科技进步奖二等奖(J-17-2-18-R01)，项目负责人获2017年江西省百千万人才工程，2016年江西省杰出青年人才基金，培养研究生2名。