LncRNA GAS8-AS inhibits colorectal cancer (CRC) cell proliferation by downregulating lncRNA AFAP1-AS1.

LncRNA GAS8-AS1 inhibits thyroid carcinoma, while its role in colorectal cancer (CRC) is unknown. In the present study we found that plasma GAS8-AS1 was upregulated in early stage CRC patients, and downregulation of GAS8-AS1 effectively distinguished CRC patients from healthy controls. LncRNA AFAP1-AS1 was upregulated in CRC patients and was inversely correlated with GAS8-AS1 only in CRC patients but not in healthy controls. GAS8-AS1 overexpression mediated the downregulation of AFAP1-AS1 in colon cancer cells, while AFAP1-AS1 overexpression did not significantly affect GAS8-AS1 expression. Expression level of GAS8-AS1 decreased, while expression level of AFAP1-AS1 increased with the increase of primary tumor diameters. GAS8-AS1 overexpression led to inhibited, while AFAP1-AS1 overexpression led to promoted proliferation of CRC cells, and AFAP1-AS1 overexpression reduced the inhibitory effects of GAS8-AS1 overexpression on cancer cell proliferation. Therefore, GAS8-AS may inhibit CRC cell proliferation by downregulating AFAP1-AS1.