title: MicroRNA-23a antisense enhances 5-fluorouracil chemosensitivity through APAF-1/caspase-9 apoptotic pathway in colorectal cancer cells.
abstract: Current literature provided information that alteration in microRNA expression impacted sensitivity or resistance of certain tumor types to anticancer treatment, including the possible intracellular pathways. The microRNA-23a (miR-23a)-regulated apoptosis in response to the 5-fluorouracil (5-FU)-induced mitochondria-mediated apoptotic pathway was determined in this study. The miR-23a expression in 5-FU-treated and untreated colon cancer cells and tissues was assessed using real-time PCR analysis. To determine the function of miR-23a in the regulation of 5-FU-induced apoptosis, cell-proliferation, cytotoxicity, and apoptosis analyses were performed. Dual luciferase reporter assay was used to identify the apoptosis-related target gene for miR-23a. The activity of caspases-3, -7, and -9 were also assessed in miR-23a antisense and 5-FU treated tumor cells. A xenograft tumor model was established to evaluate the biological relevance of altered miR-23a expression to the 5-FU-based chemotherapy in vivo. We found that the expression of miR-23a was increased and the level of apoptosis-activating factor-1 (APAF-1) was decreased in 5-FU-treated colon cancer cells compared to untreated cells. The activation of the caspases-3 and 7 was increased in miR-23a antisense and 5-FU-treated colon cancer cells compared to negative control. APAF-1, as a target gene of miR-23a, was identified and miR-23a antisense-induced increase in the activation of caspase-9 was observed. The overexpression of miR-23a antisense up-regulated the 5-FU induced apoptosis in colon cancer cells. However, the miR-23a knockdown did not increase the antitumor effect of 5-FU in xenograft model of colon cancer. This study shows that miR-23a antisense enhanced 5-FU-induced apoptosis in colorectal cancer cells through the APAF-1/caspase-9 apoptotic pathway.
authors.affiliation: Department of Medical Genetics, Institute of Genetics, Second Military Medical University, Shanghai, China.
authors.forename: Jingli
authors.initials: J
authors.lastname: Shang
authors.forename: Fu
authors.initials: F
authors.lastname: Yang
authors.forename: Yuzhao
authors.initials: Y
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Geng
authors.initials: G
authors.lastname: Xue
authors.forename: Qian
authors.initials: Q
authors.lastname: Mei
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Shuhan
authors.initials: S
authors.lastname: Sun
mesh_terms: D000368:Aged; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D053477:Apoptotic Protease-Activating Factor 1 / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology* / Q000627:therapeutic use; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells / Q000187:drug effects; D019073:HT29 Cells / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: C506592:APAF1 protein, human; D000964:Antimetabolites, Antineoplastic; D053477:Apoptotic Protease-Activating Factor 1; C552430:MIRN23a microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D053453:Caspase 9; D005472:Fluorouracil
keywords: 5-FLUOROURACIL (5-FU); APOPTOSIS; Apoptosis-Activating Factor-1(APAF-1); COLORECTAL CANCER (CRC); microRNA-23a (miR-23a)