Regulation of Colorectal Carcinoma Stemness, Growth, and Metastasis by an miR-200c-Sox2-Negative Feedback Loop Mechanism

• Published in: Clinical cancer research 2014-05, Vol.20 (10), p.2631-2642
• Main Authors: LU, Yan-Xia, LI YUAN, XUE, Xiao-Lei, MIN ZHOU, YAN LIU, CHAO ZHANG, LI, Jing-Ping, LIN ZHENG, MIN HONG, LI, Xue-Nong
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms - genetics; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; Feedback, Physiological; Gastroenterology. Liver. Pancreas. Abdomen; Gene Expression Regulation, Neoplastic; HCT116 Cells; HEK293 Cells; HT29 Cells; Humans; Medical sciences; Mice, Inbred BALB C; Mice, Nude; MicroRNAs - genetics; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Neoplasm Metastasis; Neoplastic Stem Cells - metabolism; Neoplastic Stem Cells - pathology; Phosphatidylinositol 3-Kinases - metabolism; Proto-Oncogene Proteins c-akt - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; SOXB1 Transcription Factors - genetics; SOXB1 Transcription Factors - metabolism; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Transplantation, Heterologous; Tumor Burden - genetics; Tumors
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.ccr-13-2348

To elucidate a novel mechanism of miR-200c in the regulation of stemness, growth, and metastasis in colorectal carcinoma (CRC). Quantitative reverse transcription PCR was used to quantify miR-200c expression in CRC cell lines and tissues. A luciferase assay was adopted for the target evaluation. The functional effects of miR-200c in CRC cells were assessed by its forced or inhibited expression using lentiviruses. MiR-200c was statistically lower in CRC clinical specimens and highly metastatic CRC cell lines compared with their counterparts. Sox2 was validated as a target for miR-200c. The knockdown of miR-200c significantly enhanced proliferation, migration, and invasion in CRC cell lines, whereas the upregulation of miR-200c exhibited an inverse effect. Moreover, rescue of Sox2 expression could abolish the effect of the upregulation of miR-200c. In addition, the reduction of miR-200c increased the expression of CRC stem cell markers and the sphere-forming capacity of CRC cell lines. Further study has shown that miR-200c and Sox2 reciprocally control their expression through a feedback loop. MiR-200c suppresses the expression of Sox2 to block the activity of the phosphoinositide 3-kinase (PI3K)-AKT pathway. Our findings indicate that miR-200c regulates Sox2 expression through a feedback loop and is associated with CRC stemness, growth, and metastasis.