WTAP Regulates TRAF6 in Experimental HCC Models

Researchers from Dongguan First Hospital affiliated to Guangdong Medical University have reported that the Wilms tumor 1-associated protein, known as WTAP, influences the expression of TNF receptor-associated factor 6, or TRAF6, in experimental models of hepatocellular carcinoma. This study, published in Frontiers in Cell and Developmental Biology, investigates the epitranscriptomic mechanisms that contribute to aggressive tumor behavior and reduced sensitivity to antiangiogenic therapy. The findings indicate that WTAP contributes to cellular and xenograft phenotypes partly through the post-transcriptional regulation of TRAF6, a process associated with altered m6A enrichment and mRNA stability.

Hepatocellular carcinoma is characterized as a highly vascular malignancy with marked tumor vascular plasticity. Phenotypes associated with vasculogenic mimicry, or VM, have been linked to aggressive tumor behavior. However, the specific epitranscriptomic mechanisms contributing to these phenotypes in HCC remained incompletely defined prior to this investigation. The study examined whether WTAP regulates cell growth and vascular plasticity-associated phenotypes through m6A-associated post-transcriptional regulation of TRAF6.

The experimental design involved measuring WTAP and TRAF6 expression in HepG2 and BEL-7402 cells, as well as a hepatocyte comparator, using RT-qPCR and Western blotting. Gain- and loss-of-function experiments were performed to assess cell viability, wound closure, invasion, and the ability of the examined cells to support vascular-like network formation in tumor cell-HUVEC co-culture. The researchers also evaluated the expression of vascular plasticity- and EMT-associated proteins.

To evaluate the specific molecular mechanisms, MeRIP-qPCR was used to assess m6A enrichment of TRAF6 transcripts, while an Actinomycin D chase assay was performed to assess TRAF6 mRNA stability. Additional aspects of TRAF6 regulation were examined using WT/MUT reporter assays, YTHDF1 RNA immunoprecipitation followed by qPCR, and YTHDF1 depletion. Subcutaneous xenograft models were utilized to evaluate tumor growth and the presence of PAS-positive/CD31-negative VM-like structures.

The results demonstrated that WTAP and TRAF6 were upregulated in the examined cells. WTAP overexpression enhanced cell viability, wound closure, invasion, and tumor cell-supported vascular-like network formation. WTAP manipulation altered TRAF6 mRNA abundance, m6A enrichment, and decay, with the effect being greater on the WT reporter than the MUT reporter.

Further experiments revealed that YTHDF1 depletion reduced the associated TRAF6 protein increase despite persistently elevated mRNA levels. TRAF6 knockdown attenuated WTAP-driven phenotypes and tumor growth, while TRAF6 overexpression partially rescued the effects of WTAP knockdown. PAS/CD31 staining provided qualitative evidence of VM-like morphology in the xenograft models. These findings support a functional link between WTAP, TRAF6, and vascular plasticity in experimental HCC models.

The authors conclude that WTAP contributes to the observed cellular and xenograft phenotypes partly through TRAF6 post-transcriptional regulation associated with altered m6A enrichment and mRNA stability. The precise m6A sites and the perfusion of VM-like structures remain unclear.

Subject of Research: Epitranscriptomic regulation of vascular plasticity in hepatocellular carcinoma

Article Title: WTAP regulates TRAF6 expression and vascular plasticity-associated phenotypes in experimental cell models

Article References: Liang, M., Wang, W., & Wang, W. (2026). WTAP regulates TRAF6 expression and vascular plasticity-associated phenotypes in experimental cell models. Frontiers in Cell and Developmental Biology, 14, Article 1773936. https://doi.org/10.3389/fcell.2026.1773936

Image Credits: AI Generated

DOI: 10.3389/fcell.2026.1773936

Keywords: Hepatocellular Carcinoma, WTAP, TRAF6, m6A Modification, Vasculogenic Mimicry, Vascular Plasticity, Epitranscriptomics, Tumor Biology, regulates, expression, vascular, plasticity-associated