Regulatory Role of Doxycycline on Expression of mi-RNA in Tumorigenesis Pathway of Colorectal Cancer

Downregulation of mir-143 and mir-145 has been demonstrated as a common feature of colon cancer. Several studies have shown that upregulation of mir-143 and mir-145 may be a good aspect for therapeutic purposes in the treatment of colon cancer. Doxycycline an anti-tumorigenic agent, was studied to determine the modulation of mir-143 and mir-145 expression in DMH-induced colon cancer in rats. We have found that doxycycline (DMH/DOX) unexpectedly increased aberrant crypt foci (ACFs) in DMH treated rats and caused progression of colonic tumor growth. Further analysis of mir-143 and mir-145 expression in control and treated rats, showed that compared to controls the expression of mir-143 and mir-145 was diminished in DMH/DOX treated rats. The data suggest that Doxycycline enhances tumorous growth in colon of DMH treated rats and does not modulate the expression of mir-143 and mir-145 in colon cancer.