Gao Su-Jie, Ren Sheng-Nan, Liu Yi-Ting, Yan Hong-Wei, Chen Xue-Bo
Department of Anesthesia, China-Japan Union Hospital of Jilin University, Changchun, 130033 Jilin Province, China.
Department of General Surgery, China-Japan Union Hospital of Jilin University, Changchun, 130033 Jilin Province, China.
Mol Ther Oncolytics. 2021 Jul 10;23:14-25. doi: 10.1016/j.omto.2021.06.012. eCollection 2021 Dec 17.
5-Fluorouracil (5-Fu) is a widely applied anti-cancer agent against colorectal cancer (CRC), yet a number of CRC patients have developed resistance to 5-Fu-based chemotherapy. The epidermal growth factor receptor (EGFR) is recognized as an oncogene that promotes diverse cancer progresses. In addition, long noncoding RNAs (lncRNAs) are essential regulators of cancers. Here we report that EGFR and lncRNA-FGD5-AS1 promoted 5-Fu resistance of CRC. By establishing the 5-Fu-resistant CRC cell line, we detected that EGFR, FGD5-AS1, and glucose metabolism were significantly elevated in 5-Fu-resistant CRC cells. A microRNA-microarray analysis revealed that miR-330-3p functions as a downstream effector of FGD5-AS1. FGD5-AS1 directly sponged miR-330-3p to form a competing endogenous RNA (ceRNA) network, leading to inhibition of miR-330-3p expression. Furthermore, bioinformatics analysis revealed that Hexokinase 2 (HK2) was a potential target of miR-330-3p, which was validated by luciferase assay. Rescue experiments demonstrated that FGD5-AS1 promotes glycolysis through modulating the miR-330-3p-HK2 axis, leading to 5-Fu resistance of CRC cancer cells. Finally, and xenograft experiments consistently demonstrated that inhibition of EGFR by the specific inhibitor erlotinib effectively enhanced the anti-tumor toxicity of 5-Fu by targeting the EGFR-FGD5-AS1-miR-330-3p-HK2 pathway. In summary, this study demonstrates new mechanisms of the EGFR-modulated 5-Fu resistance through modulating the noncoding RNA network, contributing to development of new approaches against chemoresistant CRC.
5-氟尿嘧啶（5-Fu）是一种广泛应用于治疗结直肠癌（CRC）的抗癌药物，但许多CRC患者对基于5-Fu的化疗产生了耐药性。表皮生长因子受体（EGFR）被认为是一种促进多种癌症进展的癌基因。此外，长链非编码RNA（lncRNA）是癌症的重要调节因子。在此我们报告，EGFR和lncRNA-FGD5-AS1促进了CRC对5-Fu的耐药性。通过建立5-Fu耐药的CRC细胞系，我们检测到EGFR、FGD5-AS1和糖代谢在5-Fu耐药的CRC细胞中显著升高。一项微小RNA微阵列分析显示，miR-330-3p作为FGD5-AS1的下游效应分子发挥作用。FGD5-AS1直接吸附miR-330-3p以形成竞争性内源RNA（ceRNA）网络，导致miR-330-3p表达受到抑制。此外，生物信息学分析显示己糖激酶2（HK2）是miR-330-3p的潜在靶标，这通过荧光素酶测定得到验证。挽救实验表明，FGD5-AS1通过调节miR-330-3p-HK2轴促进糖酵解，导致CRC癌细胞对5-Fu产生耐药性。最后，体外和体内异种移植实验一致表明，特异性抑制剂厄洛替尼对EGFR的抑制通过靶向EGFR-FGD5-AS1-miR-330-3p-HK2途径有效地增强了5-Fu的抗肿瘤毒性。总之，本研究通过调节非编码RNA网络证明了EGFR调节5-Fu耐药性的新机制，有助于开发针对化疗耐药CRC的新方法。
