Analysis Of Microrna Expression In Colorectal Cancer With Or Without Lymph Node Metastasis And Its Possible Mechanism In The Metastasis

Colorectal cancer is the most common gastrointestinal cancer worldwide.In recent20years, the incidence of colorectal cancer is increasing in most contries of the world. In our country colerectal cancer has the same status,the incidence rate of which ranks third place among all kinds of malignant neoplasm. Metastasis is the most important cause of death for malignant tumors, including colorectal cancer.Ninety percent deaths of cancer are due to metastatic disease. Lymph node metastasis is the main metastasis rount of colorectal cancer,yet the molecular mechanism of which remains unclear.MicroRNAs are19-24nt in length,highly conserved noncoding RNAs that control gene expression post-transpriptionally.MicroRNAs play important roles in cell proliferation,differentiation,and apoptosis. Recent investigations confirmed that microRNAs play important part in human tumors. It has potential to be oncogene or anti-tumor gene. More and more evidence indicate that microRNA and metastasis has close ralation.Our microarray analysis demonstrated the difference of the expression of miR-29b,miR-95,miR-100,miR-125b,miR-152,miR-199b,miR-376c and miR-145in colorectal cancer with or without lymph node metastasis. We found that the downregution of miR-29b and miR-95, as well as the upregulation of miR-100, miR-125,miR-152,miR-199b,miR-376c and miR-145is significantly corelated with lymph node metastasis in CRC patients. We detected the expression levels of these microRNAs by real time PCR assay in198CRC patients and found the upregulation of miR-29b,miR-100,miR-125b,miR-152,miR-199b,miR-376c and miR-145. Deregulated expression of miR-145modulates the motility and invasion but not proliferation of CRC cells in vitro.In conclusion,we describe novel findings of miR-29b,miR-100,miR-125b, miR-152,miR-199b,miR-376c and miR-145related with colorectal cancer lymph node metastasis.This study suggested that the upregulation of miR-29b,miR-100,miR-125b, miR-152,miR-376c and miR-145exerts potential metastasis-promoting effect in CRC.