lncRNA DGCR5 inhibits the proliferation of colorectal cancer cells by downregulating miR‑21

Long non-coding RNA (lncRNA) DiGeorge syndrome critical region gene 5 (DGCR5) serves roles as a tumor suppressor or oncogene in different types of cancer. The current study aimed to explore the role of DGCR5 in colorectal cancer (CRC). It was revealed that the expression of DGCR5 was downregulated, while microRNA (miR)-21 was upregulated in CRC. The expression level of DGCR5 in tumor tissue decreased, while expression levels of miR-21 increased, with advancing stages of the disease. The expression levels of DGCR5 and miR-21 were inversely associated in tumor tissues. In CRC cells in vitro, miR-21 overexpression failed to significantly affect DGCR5, while DGCR5 overexpression resulted in reduced expression levels of miR-21. DGCR5 overexpression showed no significant effects on cancer cell migration and invasion, but suppressed cancer cell proliferation in vitro. miR-21 overexpression increased cancer cell proliferation and attenuated the effects of DGCR5 overexpression. Therefore, lncRNA DGCR5 may inhibit the proliferation of CRC cells by downregulating miR-21.