The role of miRNA-21 and epithelial mesenchymal transition (EMT) process in colorectal cancer

Aims The study was conducted to assess the expression levels of epithelial mesenchymal transition (EMT) proteins (E-cadherin, N-cadherin, snail-1 and vimentin) and miRNA-21. In addition, we correlated these data with clinicopathological features in Colorectal cancer. Methods H&E slides from a total of 59 formalin fixed paraffin embedded tissue blocks were examined by a pathologist to demarcate normal and tumour regions. Immunohistochemical analysis of mismatch repair proteins (MLH1, MSH2 and MSH6) and EMT markers (E-cadherin, N-cadherin, snail-1 and vimentin) was performed. The miRNA-21 expression levels were determined using qRT-PCR and the data was analysed using the relative quantification method. The Fisher's exact and Pearson's chi(2) tests were used to correlate snail-1, E-cadherin, miRNA-21 and clinicopathological data. Results Our results showed a statistically significant correlation between high miRNA-21 expression levels and E-cadherin positive cases. There was also an association between high miRNA-21 expression levels and negative snail-1 expression. No significant correlation was seen between miRNA-21 expression levels and clinicopathological features. Moreover, high expression levels of miRNA-21 were significantly associated with the sporadic cases. Conclusions Our data suggest that miRNA-21 in association with E-cadherin and snail-1 does not play a significant role in the development and progression of this disease.