LAUSR

The N6‐methyladenosine (m6A) modification is one of the most prevalent methylations in eukaryotic messenger RNA (mRNA), and it is essential for the development of many important biological processes such as multiple types of tumors. One of the most important enzymes catalyzing generation of m6A on mRNA is Wilms' tumor 1‐associating protein (WTAP); however, the potential role of WTAP in endometrial cancer (EC) still remains unknown. Here, we investigated WTAP expression level in cancer tissue and paracancerous tissue from an EC patient. Subsequently, WTAP was knocked down by small interfering RNA in EC cell line of Ishikawa and HEC‐1A, respectively. Cell proliferation, migration, and invasion were studied. The expression of caveolin‐1 (CAV‐1) was detected by quantitative polymerase chain reaction (qPCR). The enrichments of m6A and METTL3 on CAV‐1 were detected using RNA immunoprecipitation‐qPCR. The activity of nuclear factor‐κB (NF‐κB) was studied using Western blot. We observed that WTAP was dramatically upregulated in the cancer tissue, and there was an enhancement in cell proliferation, migration, and invasion and a decrease in EC apoptosis in vivo and in vitro, which indicated higher tumor malignancy and worse survival outcome. After WTAP was knocked down in EC cells, CAV‐1 was significantly upregulated and the enrichments of m6A and METTL3 at 3′‐untranslated region (UTR) region of CAV‐1 were decreased. Moreover, the activity of NF‐κB signaling pathway was inhibited by its regulator CAV‐1. Taken together, we concluded that WTAP could methylate 3′‐UTR of CAV‐1 and downregulate CAV‐1 expression to activate NF‐κB signaling pathway in EC, which promoted EC progression.