Down-regulated MiRNA 29-b as a diagnostic marker in colorectal cancer and its correlation with ETV4 and Cyclin D1 immunohistochemical expression

Abstract

BACKGROUND: Colorectal cancer (CRC) is the most common malignant tumor of the gastrointestinal tract with unfavorable prognosis. Therefore, novel biomarkers that may be used for new diagnostic strategies and drug-targeting therapy should be developed. OBJECTIVES: To investigate the expression of miR-29b in CRC and its association with ETV4 and cyclin D1 expression. Moreover, the current work aims to investigate the association between them and the clinicopathological features of CRC. METHODS: The expression of miR-29b and ETV4 (by qRT-PCR) and ETV4 and cyclin D1 (immunohistochemistry) was investigated in 65 cases of colon cancer and surrounding healthy tissues. RESULTS: MiR-29b down-regulated and ETV4 and Cyclin D1 up-regulated significantly in colon cancer tissues compared to normal nearby colonic tissues. In addition, significant associations between ETV4 and cyclin D1 expressions and progressive stage and lymph node (LN) metastasis (P< 0.001 for each) were found. Furthermore, there was a negative correlation between miR-29b gene expression and ETV4 gene expression (r=-0.298, P<0.016). CONCLUSION: Down-regulation of miR-29b and over-expression of ETV4 and cyclin D1 may be utilized as early diagnostic marker for development of colon cancer. ETV4 and cyclin D1 correlate with poor prognostic indicators and considered as a possible target for therapy in colon cancer.