All-Trans Retinoic Acid Enhances Chemosensitivity to 5-FU by Targeting miR-378c/E2F7 Axis in Colorectal Cancer. (21st July 2021)

• Record Type: Journal Article
• Authors: Li, Ji; Xiang, Qing; Wang, Mei; Zhang, Hongchang; Liang, Rong
• Other Names: Khan Muhammad Wasim Academic Editor.
• Is Part Of: Journal of oncology. Volume 2021(2021)
• Publication Date: 2021-07-21
• Subjects: Oncology -- Research -- Periodicals; Tumors -- Periodicals; Neoplasms; Oncology -- Research; Tumors; Periodicals; Periodicals; 616.994
• DOI: 10.1155/2021/5338934
• Languages: English
• ISSNs: 1687-8450

Abstract

Abstract : Colorectal carcinoma (CRC), a life-threatening malignancy, has been found to present resistance to 5-fluorouracil (5-FU) and cause a poor prognosis for patients. Previous studies have proved that all-trans retinoic acid (ATRA) could inhibit the development of CRC cells. In addition, miR-378c was discovered to exert a vital role in various cancers. In this study, we utilized MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide), transwell assay, and flow cytometry to confirm that ATRA was able to enhance the inhibitory effects of 5-FU on HCT116 cells effectively by promoting cell apoptosis. Then, ENCORI database (http://starbase.sysu.edu.cn/ ) was employed to predict that miR-378c was downregulated dramatically in CRC and E2F7 was the direct target of miR-378c. QRT-PCR (quantitative real-time polymerase chain reaction) was conducted to verify that the expression level of miR-378c was decreased while E2F7 expression was upregulated in CRC tissues compared with para-carcinoma tissues. Additionally, treatment of 5-FU combined with ATRA could increase miR-378c expression, whereas it decreased the expression of E2F7. Dual-Luciferase Reporter assay results revealed that miR-378c could regulate the load of E2F7 by binding to its 3′UTR directly. Furthermore, miR-378c inhibitor or vector with E2F7 partially counteracted the effects of 5-FU combined with ATRA on viability, migration, invasion, and apoptosis of HCT116 cells. In conclusion, our study aims to confirm that ATRA enhances chemosensitivity to 5-FU of patients with CRC and expound the potential molecular mechanisms.