DataSheet_1_N6-Methyladenosine Modification of PTTG3P Contributes to Colorectal Cancer Proliferation via YAP1.doc

BackgroundLong noncoding RNAs (lncRNAs) have emerged to have irreplaceable roles in the epigenetic regulation of cancer progression, but their biological functions in colorectal cancer (CRC) remain unclear.
MethodsLncRNA expression profiles in CRC tissue and their normal counterpart were explored. Through gain and loss of function approaches, the role of lncRNA PTTG3P was validated in relevant CRC cells and subcutaneous tumor model. The correlations of PTTG3P expression with clinical outcomes were assessed.
ResultsPTTG3P was upregulated in CRC tissues and was closely correlated with unsatisfactory prognosis. PTTG3P facilitated glycolysis and proliferation, and the transcriptional regulator YAP1 was necessary for PTTG3P-induced proliferation. Mechanistically, the N6-methyladenosine (m6A) subunit METTL3 increased PTTG3P expression by influencing its stability, while insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) could identify PTTG3P m6A methylation status and bind to it. IGF2BP2 knockdown partly recovered PTTG3P expression induced by METTL3, indicating that METTL3-regulated PTTG3P expression depended on the presence of IGF2BP2. Finally, rescue assays validated the critical role of the METTL3/PTTG3P/YAP1 axis on CRC proliferation.
ConclusionsPTTG3P is an independent prognostic biomarker for CRC. The METTL3/PTTG3P/YAP1 axis promotes the progression of CRC and is a promising treatment target.

背景：长链非编码RNA（long noncoding RNAs，lncRNAs）已被证实于癌症进展的表观遗传调控中发挥不可替代的作用，但其在结直肠癌（colorectal cancer，CRC）中的生物学功能仍未明确。
方法：本研究分析了结直肠癌组织及其正常对照组织中的lncRNA表达谱。通过功能获得与功能缺失实验，验证了lncRNA PTTG3P在相关结直肠癌细胞及皮下移植瘤模型中的作用，并评估了PTTG3P表达与临床预后的相关性。
结果：PTTG3P在结直肠癌组织中呈高表达，且与不良预后密切相关。PTTG3P可促进糖酵解与细胞增殖，转录调控因子YAP1是PTTG3P诱导细胞增殖所必需的分子。机制层面，N6-甲基腺苷（N6-methyladenosine，m6A）修饰酶亚基METTL3通过影响PTTG3P的稳定性上调其表达；而胰岛素样生长因子2 mRNA结合蛋白2（insulin-like growth factor 2 mRNA binding protein 2，IGF2BP2）可识别PTTG3P的m6A修饰位点并与之结合。敲低IGF2BP2可部分逆转METTL3诱导的PTTG3P表达上调，提示METTL3对PTTG3P的调控依赖于IGF2BP2的存在。最后，挽救实验验证了METTL3/PTTG3P/YAP1轴在结直肠癌细胞增殖中的关键作用。
结论：PTTG3P是结直肠癌的独立预后生物标志物。METTL3/PTTG3P/YAP1轴可促进结直肠癌进展，是颇具前景的治疗靶点。