转运RNA衍生片段在甲状腺癌发病机制中的作用

Role of tRNA-derived Fragments in the Mechanism of Thyroid Carcinoma

【目的】探讨tRNA衍生片段(tRFs)3'tiR_026_GlnCTG(n)在甲状腺乳头状癌(PTC)中的表达及其致癌机制。【方法】首先取2对PTC和邻近正常甲状腺组织用于高通量芯片检测,筛选差异tRFs。在芯片结果基础上,我们在10对PTC和邻近正常甲状腺组织中验证了差异明显的tRNA衍生片段的表达。接着扩大样本量,继续收集共46例患者的PTC和邻近正常甲状腺组织,通过定量聚合酶链反应(qPCR)验证3'tiR_026_GlnCTG(n)的表达量。将3'tiR_026_GlnCTG(n)的mimic转染到PTC细胞系中,通过定量反转录聚合酶链反应(qRT-PCR)检测表达水平,证实成功转染。同时,裂解转染的细胞系,提取蛋白,用包括MEK/ERK/p90RSK信号通路在内的相关抗体进行孵育,并进行蛋白免疫印迹(WB)。【结果】3'tiR_026_GlnCTG(n)是PTC组织与相邻正常甲状腺组织中表达水平差异最显著的tRFs之一(P<0.05)。过表达3'tiR_026_GlnCTG(n)促进KTC1细胞及BCPAP细胞的迁移、侵袭和增殖能力,用MEK/ERK通路抑制剂处理后降低KTC1细胞及BCPAP细胞迁移、侵袭和增殖能力。在3'tiR_026_GlnCTG(n)过表达的细胞中,MEK、ERK及其下游靶点p90RSK的磷酸化水平显著升高。【结论】3'tiR_026_GlnCTG(n)可能通过激活MEK/ERK/p90RSK通路参与PTC的发生、发展。这将对PTC的发病机制提供新的认识,并为其治疗策略提供新思路。

【Objective】To investigate the expression of tRNA-derived fragments(tRFs)3'tiR_026_GlnCTG(n)in PTC and its carcinogenic mechanism.【Methods】First,two pairs of PTC and adjacent normal thyroid tissues were used for high-throughput microarray to screen differential tRFs.Based on the microarray results,we verified the expression of sig⁃nificantly different tRFs in 10 pairs of PTC and adjacent normal thyroid tissues.Then,we increased sample sizes and veri⁃fied the expression of 3'tiR_026_GlnCTG(n)in another 46 pairs of PTC and adjacent normal thyroid tissues by Quantita⁃tive PCR(qPCR).Mimics of3'tiR_026_GlnCTG(n)were transfected into PTC cell lines.The expression level was verified by quantitative reverse transcription polymerase chain reaction(qRT-PCR)and the transfection was confirmed.Mean⁃while,the transfected cell lines were lysed,protein was extracted,incubated with relevant antibodies including the MEK/ERK/p90RSK signaling pathway and the western blotting was performed.【Results】3'tiR_026_GlnCTG(n)is one of the most significantly upregulated tRFs between PTC tissues and adjacent normal tissues.Overexpression of 3'tiR_026_GlnCTG(n)promoted migration,invasion and proliferation in KTC1 and BCPAP cells.MEK/ERK pathway inhibitors decrease the migration,invasion and proliferation in KTC1 and BCPAP cells.The phosphorylation of MEK,ERK and their downstream target p90RSK was significantly increased in 3'tiR_026_GlnCTG(n)-overexpressing cells.【Conclusions】3'tiR_026_GlnCTG(n)might play a key oncogenic role in PTC tumorigenesis and development by activating the MEK/ERK/p90RSK pathway.It will provide new insight into the pathogenesis of PTC and may lead to effective therapeutic strate⁃gies.