RETRACTED ARTICLE: Long noncoding RNA LINC01234 promotes serine hydroxymethyltransferase 2 expression and proliferation by competitively binding miR-642a-5p in colon cancer

Long noncoding RNAs (lncRNAs) have been indicated as important regulators in various human cancers. However, the overall biological roles and clinical significance of most lncRNAs in colon carcinogenesis are not fully understood. Hence, we investigated the clinical significance, biological function and mechanism of LINC01234 in colon cancer. First, we analyzed LINC01234 alterations in colon cancer tissues and corresponding paracancerous tissues through the analysis of sequencing data obtained from The Cancer Genome Atlas and colon cancer patients. Next, we evaluated the effect of LINC01234 on colon cancer cell proliferation and its regulatory mechanism of serine hydroxymethyltransferase 2 (SHMT2) by acting as a competing endogenous RNA (ceRNA). We found that LINC01234 expression was significantly upregulated in colon cancer tissues and was associated with a shorter survival time. Furthermore, the knockdown of LINC01234 induced proliferation arrest via suppressing serine/glycine metabolism. Mechanistic investigations have indicated that LINC01234 functions as a ceRNA for miR-642a-5p, thereby leading to the derepression of its endogenous target serine hydroxymethyltransferase 2 (SHMT2). LINC01234 is significantly overexpressed in colon cancer, and the LINC01234–miR642a-5p–SHMT2 axis plays a critical role in colon cancer proliferation. Our findings may provide a potential new target for colon cancer diagnosis and therapy.