Long non-coding RNA LINC00858 inhibits colon cancer cell apoptosis, autophagy, and senescence by activating WNK2 promoter methylation

Exp Cell Res. 2020 Nov 1;396(1):112214. doi: 10.1016/j.yexcr.2020.112214. Epub 2020 Aug 6.

Abstract

Accumulating evidence shows the involvement of long non-coding RNAs (lncRNAs) in tumorigenesis of many types of human cancers. However, the role of LINC00858 in colon cancer has not been fully elucidated. Therefore, we investigated the involvement of LINC00858 in the progression of colon cancer and identified its downstream targets. After examining the expression of LINC00858 in colon cancer tissues and cell lines, we then identified the possible interaction between LINC00858 and WNK lysine deficient protein kinase 2 (WNK2) by fluorescence in situ hybridization, RNA immunoprecipitation, chromatin immunoprecipitation, and RNA pull-down assays. Next, the role of the LINC00858/WNK2 axis was explored by evaluating the apoptosis, autophagy, and senescence of colon cancer cells in vitro after ectopic expression and depletion experiments in HCT116 cells. Moreover, a mouse xenograft model of HCT116 cells was established to verify the function of the LINC00858/WNK2 axis in vivo. There was high expression of LINC00858 and low expression of WNK2 in colon cancer tissues and cell lines. Silencing of LINC00858 promoted apoptosis, senescence, and autophagy in colon cancer cells. Additionally, the enrichment of WNK2 was promoted when LINC00858 bound to DNA methyltransferases. Furthermore, in vivo assays demonstrated that silencing of LINC00858 resulted in inhibited tumor growth by upregulating WNK2. In summary, LINC00858 acts as a tumor-promoting lncRNA in colon cancer by downregulating WNK2. Our results may provide novel targets for the treatment for colon cancer.

Keywords: Colon cancer; DNA methyltransferase; Long non-coding RNA LINC00858; WNK lysine deficient protein kinase 2.