长链非编码RNA SEMA6A-AS1在胃肠道间质瘤伊马替尼继发耐药中的作用及机制研究

Tyrosine kinase receptor inhibitor imatinib can effectively control gastrointestinal stromal tumor (GIST), however, imatinib resistance and tumor recurrence have become serious problems in the clinical treatment of GIST, partial mechanisms remains unknown. We have successfully constructed secondary imatinib resistant GIST cell lines, RNA-seq combined with in vitro experiments were used to screen out differential expressed long non-coding RNA (lncRNA) correlated to imatinib resistance. We firstly found that the expression of lncRNA SEMA6A-AS1 was up-regulated in recurrent GIST after imatinib treatment, which correlated with clinically poor imatinib response. Modulating the expression of lncRNA SEMA6A-AS1 could significantly affect the imatinib resistance in GIST cells. Further study found that lncRNA SEMA6A-AS1 could regulate the transcription of nearby gene SEMA6A. This study aims to use the above findings, further explore the clinical value of lncRNA SEMA6A-AS1 and SEMA6A in the prognosis of GIST after imatinib therapy. Through in vitro and in vivo experiments and CHIRP-seq, we are going to further study the biological function of lncRNA SEMA6A-AS1 in GIST, and the underlying mechanisms that induced imatinib resistance in GIST, to reverse the resistance to imatinib in clinical treatment of GIST and provide new predictor and potential therapeutic target.

受体酪氨酸激酶抑制剂伊马替尼能够有效治疗胃肠道间质瘤(GIST)，然而肿瘤继发耐药复发已成为目前临床GIST治疗的难题，部分机制仍待研究。我们在前期的工作中构建了伊马替尼继发耐药细胞株，通过RNA-seq及体外功能实验初步结果筛选与伊马替尼耐药相关的差异表达长链非编码RNA(lncRNA)，首次发现lncRNA SEMA6A-AS1在耐药复发的GIST组织中表达上调，并与伊马替尼治疗预后相关，改变其表达能够影响GIST细胞对伊马替尼药物的耐受性，并影响其近程基因SEMA6A的表达，本研究拟利用上述发现，进一步探讨lncRNA SEMA6A-AS1及SEMA6A对GIST预后的临床评估价值，通过体外细胞实验、体内动物实验以及CHIRP-seq，深入探讨lncRNA SEMA6A-AS1在GIST中的生物学功能及其导致伊马替尼耐药的机制，为逆转GIST靶向治疗耐药提供新的标志物及治疗靶点。

胃肠道间质瘤（GIST）是胃肠道最常见的间叶源性肿瘤，受体酪氨酸激酶抑制剂伊马替尼能够有效治疗GIST，然而肿瘤继发耐药复发已成为目前临床GIST治疗的难题，目前尚无能准确评估GIST耐药复发的可靠指标，其部分耐药机制仍待研究。我们通过体外药物诱导成功构建了伊马替尼耐药的GIST细胞株，通过RNA-seq及体外药物实验初步结果筛选与伊马替尼耐药相关的差异表达长链非编码RNA(lncRNA)，首次发现lncRNA SEMA6A-AS1在耐药的GIST细胞株中表达显著上调，干扰其表达能够促进GIST耐药细胞株对伊马替尼的敏感性，同时发现lncRNA SEMA6A-AS1在复发耐药的gist组织中表达上调，并与伊马替尼治疗预后相关；后续的体外及体内实验证实了改变lncRNA SEMA6A-AS1的表达能够显著影响GIST细胞对伊马替尼的耐受，并影响下游的相关信号通路。进一步机制研究发现lncRNA SEMA6A-AS1能够顺式调控近程基因SEMA6A的表达，两者又同时受到转录因子E2F1的调控，以上研究结果为临床伊马替尼耐药的棘手问题提供了可能的解决思路。本研究以长链非编码RNA在耐药细胞及组织中的差异表达作为出发点，部分揭示了GIST耐药复发的潜在调控机制之一，为找到抑制GIST肿瘤进展及解决伊马替尼耐药提供了崭新的实验数据与理论基础。