AUTHOR=Qian Xiao-Lan , Zhou Fang , Xu Song , Jiang Jian , Chen Zhi-Peng , Wang Shao-Kai , Zuo Yun , Ni Chen TITLE=MiR-454-3p Promotes Oxaliplatin Resistance by Targeting PTEN in Colorectal Cancer JOURNAL=Frontiers in Oncology VOLUME=Volume 11 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2021.638537 DOI=10.3389/fonc.2021.638537 ISSN=2234-943X ABSTRACT=Colorectal cancer is one of the most common malignancies worldwide. Oxaliplatin is a first-line chemotherapeutic agent for treating advanced colorectal cancer. However, acquired resistance to oxaliplatin limits its therapeutic efficacy since the underlying mechanism remains largely unclear. In this study, we compared a panel of miRNA expression levels between oxaliplatin-sensitive and -resistant HCT-116 colorectal cancer cells, and found that miR-454-3p was the most differently expressed miRNAs and significantly up-regulated in oxaliplatin-resistant cells. Inhibition of miR-454-3p re-sensitized resistant cells to oxaliplatin and enhanced oxaliplatin-induced cellular apoptosis. Moreover, we determined that miR-454-3p promotes resistance to oxaliplatin through targeting PTEN and activating ATK signaling pathway. In vivo study revealed that overexpression miR-454-3p decrease the sensitivity of HCT-116 xenograft tumors to oxaliplatin treatment in mouse model. Clinically, high miR-454-3p expression was associated with a decreased responsiveness to oxaliplatin-based chemotherapy as well as a short progression-free survival (PFS). These data indicated that miR-434-3p might serve as a biomarker for predicting oxaliplatin sensitivity and a novel therapeutic target to overcome resistance to oxaliplatin in colorectal cancer.