ALDH1A1在弥漫大B细胞淋巴瘤化疗耐药中的作用及其机制研究

Chemotherapy resistance is the main reason for the failure in the treatment of patients with diffuse large B cell lymphoma. We have identified a stem cell marker--ALDH1A1 (aldehyde dehydrogenase 1A1) associated with chemotherapy resistance of DLBCL through differential proteomic methods. Furthermore, we have observed that ALDH1A1 mediate chemotherapy resistance in diffuse large B cell lymphoma probably through the activation of NF-κB and STAT3 signaling pathway. However，the role(s) of ALDH1A1 in chemotherapy resistance of DLBCL have not been identified completely. In order to elucidate the underlying mechanism of ALDH1A1 in chemotherapy resistance of DLBCL, both the in vitro and in vivo assays will be performed through lentiviral gene transduction, immunofluorescence, Co-Immunoprecipitation, high performance liquid chromatography and microarray methods. Furthermore, the reversal function of disulfiram (an ALDH1A1 inhibitor) in chemotherapy resistance of DLBCL will be tested. Taken together, our project purpose to demonstrate that ALDH1A1 play important roles in chemotherapy resistance and suggests a promising strategy for revering chemotherapy resistance of DLBCL.

化疗耐药一直是制约弥漫大B细胞淋巴瘤(DLBCL)疗效的瓶颈。我们前期采用蛋白质组学方法筛选DLBCL对CHOP方案耐药的相关蛋白质，发现肿瘤干细胞标志——乙醛脱氢酶家族1成员A1(ALDH1A1) 与DLBCL耐药有关。为揭示ALDH1A1在DLBCL耐药中的作用及机制，项目拟从体外、体内和临床组织样本三个层面入手，分析ALDH1A1表达水平与DLBCL耐药的关系，明确ALDH1A1高表达导致DLBCL耐药；分析ALDH1A1表达改变对STAT3和NF-κB信号通路活性的影响及其与DLBCL耐药的关系，揭示ALDH1A1高表达导致DLBCL耐药的信号机制；分析ALDH1A1抑制剂——戒酒硫能否逆转ALDH1A1介导的DLBCL耐药，为其临床应用奠定实验基础。项目研究结果将为DLBCL耐药逆转和个体化化疗提供靶点和治疗方法，具有重要的理论意义和潜在的临床应用价值。

化疗耐药是弥漫大B细胞淋巴瘤（DLBCL）疗效不佳的关键。我们前期采用蛋白质组学方法比较CHOP 方案耐药及敏感DLBCL的蛋白质表达谱差异，发现乙醛脱氢酶1A1(Aldehyde dehydrogenase 1A1，ALDH1A1)在耐药DLBCL细胞中高表达。大量的研究证实ALDH1A1与化疗耐药有关。研究发现，DLBCL中存在STAT3信号通路的激活，该通路促进DLBCL的增殖。在本课题中，我们研究ALDH1A1在DLBCL化疗耐药中的地位，及其介导化疗耐药的分子机制。.为分析ALDH1A1、STAT3、p-STAT3在DLBCL组织中的表达，我们收集88例DLBCL患者病理标本，根据患者对CHOP化疗方案的治疗反应将其分为低敏感组和高敏感组。结果显示，与高敏感组DLBCL相比，低敏感组DLBCL患者的ALDH1A1、STAT3和p-STAT3呈明显高表达，且ALDH1A1与STAT3、p-STAT3的表达呈正相关。ALDH1A1表达与Ann Arbor分期、国际预后指数（International Prognostic Index, IPI）及亚型相关。高表达的ALDH1A1预示着较差的预后。IPI评分和ALDH1A1是DLBCL病人的独立预后因素。.我们检测细胞水平ALDH1A1的表达情况，发现Farage和Pfeiffer细胞的ALDH1A1表达均显著高于正常人B细胞。构建ALDH1A1过表达和ALDH1A1敲低的Pfeiffer细胞模型，发现沉默ALDH1A1可抑制DLBCL细胞的增殖，促进凋亡，增强化疗敏感性。过表达ALDH1A1可使p-JAK2 (Y931, Y1007)、STAT3及p-STAT3(Y705, S727)的表达水平升高。.进一步分析抑制JAK/STAT3信号通路能否影响DLBCL的化疗敏感性。我们在ALDH1A1过表达的Pfeiffer细胞抑制JAK2/STAT3通路，p-JAK2 (Y931, Y1007)、STAT3、p-STAT3(Y705, S727)以及JAK2/STAT3通路下游BCL-2和Cyclin D1的表达明显下调，且能部分逆转ALDH1A1介导的化疗耐药。.该项目证实ALDH1A1通过调控JAK2/STAT3信号通路介导DLBCL的化疗耐药，这为ALDH1A1在DLBCL的耐药逆转中提供了理论和实验依据。