Long non-coding RNA LINC00997 silencing inhibits the progression and metastasis of colorectal cancer by sponging miR-512-3p

We aimed to study the role of LINC00997 in the metastasis of colorectal cancer (CRC). LINC00997 and miR-512-3p expression in the primary colorectal cancer (NCRC) tissues and metastatic colorectal cancer (MCRC) tissues were detected using RT-qPCR. The Cancer Genome Atlas database was used to evaluate LINC00997 levels in the NCRC and MCRC tissues, and the correlations of LINC00997 expression with distant metastasis (M), regional lymph node metastasis (N), age and tumor stage were analyzed. Subsequently, RT-qPCR was performed to determine the expression of metastasis-related genes in MCRC tissues and analyze the correlation of LINC00997 or miR-512-3p level with the protein expression of metastasis-related genes. In vitro, LINC00997 expression in several CRC cell lines was examined. After LINC00997 silencing, cell invasion and migration were evaluated with Transwell and wound healing assays, respectively. The expression of metastasis- and EMT-related proteins was measured. Additionally, the potential interaction between LINC00997 and miR-512-3p was verified using a luciferase reporter assay. Rescue assays were conducted to clarify the regulatory effects of LINC00997 and miR-512-3p on CRC development. Results revealed that LINC00997 was frequently overexpressed in MCRC tissues, which was positively related to the tumor metastasis and stage. Additionally, LINC00997 was significantly elevated in CRC cells and LINC00997 silencing inhibited the invasion, migration and EMT of CRC cells, which was restored by miR-512-3p inhibitor. Luciferase reporter assay confirmed that LINC00997 could target miR-512-3p. In conclusion, LINC00997 regulated the metastasis of CRC by targeting miR-512-3p, providing some insights into the regulatory mechanism of CRC.