miR-887-3p Inhibits the Progression of Colorectal Cancer via Downregulating DNMT1 Expression and Regulating P53 Expression

• Published in: Computational intelligence and neuroscience 2022-06, Vol.2022, p.7179733-13
• Main Authors: Teng, Da, Xia, Shaoyou, Hu, Shidong, Yan, Yang, Liu, Boyan, Yang, Yu, Du, Xiaohui
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Assaying; Biomarkers; Cancer therapies; Cell migration; Cell Movement - genetics; Cell proliferation; Cholecystokinin; Colon; Colon cancer; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - genetics; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; Development and progression; Diagnosis; DNA (Cytosine-5-)-Methyltransferase 1 - biosynthesis; DNA (Cytosine-5-)-Methyltransferase 1 - genetics; DNA methylation; DNMT1 protein; Down-Regulation; Epithelial cells; Epithelium; Flow cytometry; Health aspects; Heterografts; Humans; Immunohistochemistry; In vivo methods and tests; Ki-67 Antigen - metabolism; Liver cancer; Medical research; Mesenchyme; Methyltransferases; Mice; MicroRNA; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; p53 Protein; Patients; Plasmids; Proteins; Ribonucleic acid; RNA; Therapeutic targets; Transfection; Tumor cell lines; Tumor proteins; Tumor Suppressor Protein p53 - biosynthesis; Tumor Suppressor Protein p53 - genetics; Tumors; Websites; Xenografts; Xenotransplantation
• ISSN: 1687-5265; 1687-5273
• DOI: 10.1155/2022/7179733

Colorectal cancer (CRC) is the third most diagnosed cancer worldwide and the second leading cause of cancer-related deaths. Many researchers have reported that abnormal microRNAs (miRs) were expressed in CRC and participated in the occurrence and progression of CRC. However, there are few reports of miR-887-3p regulating CRC development. In the current study, we investigated the abnormal expression of miR-887-3p and also demonstrated its regulatory role and detailed molecular mechanism in CRC. Initially, miRNA expression data were obtained from TCGA-COAD that consisted of 453 CRC samples and 8 normal tissue samples. These were downloaded and analyzed to compare the expression level of miR-887-3p in CRC tissues to that in normal tissues. Moreover, 32 pairs of surgically resected CRC tumors and para-cancer tissues from our hospital were collected. Quantitative real-time PCR (qRT-PCR) was performed to detect miR-887-3p expression levels in CRC tissues, para-cancer tissues, several CRC cell lines, and an intestinal epithelial cell line. Following miR-887-3p mimic transfection in colon cancer SW480 cell line, the regulatory roles of miR-887-3p on cell proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) were detected through CCK-8, flow cytometry, transwell assay, and Western blot. After potential targeting protein was predicted by bioinformatic websites, the luciferase reporter assay and Western blot were used to confirm the target of miR-887-3p. The targeting protein expressions were detected by Western blot and qRT-PCR. The relationship between miR-887-3p level and the effect of miR-887-3p on P53 expression was evaluated by Western blot and qRT-PCR. The effects of miR-887-3p on CRC cell growth in vivo by xenograft tumor experiments were investigated, and Ki-67 in tumor tissue was determined by immunohistochemistry. Results. The COAD data demonstrated that the expression levels of miR-887-3p in CRC clinical sample tissues and cell line cultures were remarkably lower than para-cancer normal tissues and NCM460 cells (normal colonic epithelial cell line). Functional experiments demonstrated that overexpression of miR-887-3p in SW480 cells significantly reduced proliferation, migration, invasion, and EMT, and promoted cancer cell apoptosis. Additionally, Western blot, qRT-PCR, and luciferase reporter assays confirmed that DNMT1 was a downstream target of miR-887-3p. Moreover, the blocking of DNMT1 by miR-887-3p mimics also pr