lncRNA-SSR通过自噬促进肾癌舒尼替尼敏感性的作用和机制研究

Limited clinical benefit of sunitinib is a clinical challenge of metastatic renal cell carcinoma (mRCC) treatment that needs to be solved urgently. Latest studies have revealed that long noncoding RNA (lncRNA) was of great significance in drug sensitivity of targeted therapy. Meanwhile, autophagy also played a quite important role in the tumor response to drug therapy. Our previous investigation discovered a new sunitinib-sensitivity related lncRNA by RNA microarray and named it lncRNA-SSR (lncRNA represented Sunitinib Sensitivity in RCC). We also found that lncRNA-SSR could promote the sunitinib-sensitivity in vivo and vitro experiment. Furthermore, lncRNA-SSR could suppress the activity of autophagy at the same time. Therefore, we hypothesized that lncRNA-SSR may enhance the sunitinib-sensitivity by inhibiting autophagy in renal cell carcinoma treatment. To validate it, we intend to perform RACE、RNA-pulldown、RIP、CHIRP and PDX to identify the binding factor and elucidate the specific mechanism of sunitinib-sensitivity in RCC treatment from different levels. This study will lie the theoretically basis for optimization of management strategy and improvement of precise treatment of RCC patients receiving sunitinib therapy.

较低的临床获益率是舒尼替尼治疗晚期肾癌的一大难题。最新研究发现lncRNA可参与肿瘤靶向药物敏感性调控。自噬在调节肿瘤药物敏感性中也发挥重要作用。我们前期通过lncRNA芯片筛选得到一条舒尼替尼敏感性相关的新lncRNA，命名为lncRNA-SSR(lncRNA represented Sunitinib Sensitivity in RCC)，体内外实验也验证了lncRNA-SSR可增加肾癌舒尼替尼敏感性。进一步研究发现lncRNA-SSR可降低自噬通路活性。由此，我们提出“lncRNA-SSR通过抑制自噬增加肾癌舒尼替尼敏感性”的假说。本课题下一步拟采用RACE、RNA-pulldown、RIP、CHIRP、PDX模型等实验，从细胞、动物、临床样本等多个层面探讨lncRNA-SSR通过自噬促进肾癌舒尼替尼敏感性的分子机制，为优化肾癌靶向药物治疗策略，提高肾癌精准治疗水平提供理论基础。

舒尼替尼是晚期肾癌的一线治疗药物，但药物耐药的频繁出现限制了其临床应用和疗效，使得晚期肾癌患者预后不佳。阐述某些新基因在舒尼替尼敏感过程中所扮演的角色对优化舒尼替尼治疗有着重要意义。最新研究发现lncRNA可参与肿瘤靶向药物敏感性调控。自噬在调节肿瘤药物敏感性中也发挥重要作用。我们前期通过lncRNA芯片筛选得到一条舒尼替尼敏感性相关的新lncRNA，命名为lncRNA-SSR(lncRNA represented Sunitinib Sensitivity in RCC)，肾癌标本中验证发现lncRNA-SSR在肾癌舒尼替尼敏感组中明显高表达，且lncRNA-SSR的表达与舒尼替尼治疗肾癌患者预后存在相关性。高表达lncRNA-SSR的肾癌患者相较于低表达lncRNA-SSR的肾癌患者具有更好的舒尼替尼治疗效果。体外实验发现，抑制lncRNA-SSR的表达可以降低肾癌细胞系舒尼替尼敏感性，而过表达lncRNA-SSR可以增加肾癌细胞系是舒尼替尼敏感性。体内实验同样发现lncRNA-SSR 可增加肾癌舒尼替尼敏感性。进一步机制实验发现，lncRNA-SSR对自噬抑制作用，而且lncRNA-SSR可能通过自噬途径影响肾癌是舒尼替尼敏感性。机制方面我们通过RNA-pulldown证实lncRNA-SSR与ACOX1存在结合，并进一步通过功能实验证实AOCX1参与lncRNA-SSR对肾癌舒尼替尼敏感性的调节。且RT-PCR和western blot实验发现，AOCX1的表达量改变会影响肾癌细胞自噬活性。以上结果提示，lncRNA通过于AOCX1的结合影响肾癌细胞自噬活性，并进一步影响肾癌细胞舒尼替尼敏感性。本研究从细胞、动物、临床样本等多个层面探讨lncRNA-SSR通过自噬促进肾癌舒尼替尼敏感性的分子机制，为优化肾癌靶向药物治疗策略，提高肾癌精准治疗水平提供理论基础。