miR-33a抑制糖酵解途径影响黑色素瘤放射敏感性的实验研究

Radiotherapy is one of the important treatments for melanoma, and radiosensitivity is a major obstacle in clinical treatment. Our preliminary experiments revealed that miR-33a was down-regulated in melanoma cells, HIF-1α was the direct target gene of miR-33a and miR-33a significantly inhibited aerobic glycolysis and proliferation in melanoma cells. Since MicroRNA, HIF-1α and glycolysis could affect the radiosensitivity of tumor cells, we focus on the idea that miR-33a could affect the radiosensitivity of melanoma cells by inhibiting the glycolytic pathway. Our study will further confirm miR-33a inhibit the glycolysis by regulating HIF-1α and other genes, then observe the impact of miR-33a on the radiosensitivity of melanoma cells by in vitro and in vivo models. In addition, we will investigate the molecular mechanism of miR-33a affecting the radiosensitivity of melanoma cells by inhibiting glycolysis. Moreover,by using existing clinical samples, we will validate the clinical values of miR-33a and glycolytic phenotype for the prognostic assessment and recurrent prediction of melanoma patients received radiotherapy. Our study will try to identify novel targets for radiosensitivity of melanoma, which would provide scientific evidence for melanoma radiosensitivity enhancing and individualized radiotherapeutic regimen.

放射治疗为黑色素瘤重要的治疗手段之一，如何提高黑色素瘤的放射敏感性是目前亟待解决的难题。我们前期发现黑色素瘤细胞中miR-33a低表达；HIF-1α为miR-33a的直接靶基因；miR-33a明显抑制肿瘤细胞的有氧糖酵解和增殖。结合MicroRNA、HIF-1α及糖酵解均能影响肿瘤的放射敏感性，本课题以黑色素瘤细胞中miR-33a能够抑制糖酵解途径而影响肿瘤细胞放射敏感性为主轴，首先深入验证miR-33a通过调控HIF-1α等抑制糖酵解途径；再利用体内外模型观察miR-33a对黑色素瘤细胞放射敏感性的影响，并探讨miR-33a通过抑制糖酵解途径影响黑色素瘤细胞放射敏感性的分子机制；最后利用现有临床资料和标本，判定miR-33a及糖酵解表型在黑色素瘤放射治疗预后评估、复发预测中的临床价值。以求寻找黑色素瘤放射治疗新靶点，为临床上黑色素瘤的放射治疗增敏及放射治疗个体化方案提供科学依据。

本研究紧扣黑色素瘤恶性程度极高，如何提高黑色素瘤的放射敏感性是目前亟待解决的难题。本研究原创性的证实了miR-33a在黑色素瘤患者组织标本中呈低表达，发生转移的患者组织中表达量更低；对黑色素瘤细胞进行检测发现miR-33a也呈低表达，并且转移侵袭能力强的细胞表达量更低，体内外实验证实低侵袭力细胞株中下调miR-33a可显著增强黑色素瘤细胞糖酵解水平和放射抗拒性；相反地，高侵袭能力细胞株中过表达miR-33a可明显抑制黑色素瘤细胞糖酵解水平和增加放射敏感性。首次证实HIF-1a为miR-33a的直接靶基因，在黑色素瘤细胞糖酵解过程中起到关键调控作用；并对miR-33a/HIF-1a/糖酵解调控轴与黑色素瘤放射敏感性之间的关系进行深层次探索。在本项目资助下，我们的直接研究及拓展研究共发表SCI论文22篇；获得中国实用型专利9项；为临床上黑色素瘤放疗增敏剂的研发及临床应用提供了新的理论依据和新思路。该项目在理论上具有前沿性和创新性，在临床上具有一定实用性及开发潜能。