# Mebendazole inhibits PELI3-mediated ubiquitination of TRADD in non-small cell lung cancer cells

## TL;DR

This study shows that Mebendazole, a drug, can inhibit PELI3 from breaking down TRADD, a protein linked to cancer cell death in non-small cell lung cancer.

## Contribution

The study identifies PELI3 as a new E3 ubiquitin ligase for TRADD and shows Mebendazole's potential as a therapeutic in NSCLC.

## Key findings

- PELI3 reduces TRADD protein levels by ubiquitination without affecting its mRNA.
- Mebendazole inhibits PELI3 and increases TRADD expression in cancer cells.
- Mebendazole reduces cancer cell viability by modulating PELI3 and TRADD.

## Abstract

Tumor necrosis factor receptor 1-associated death domain protein (TRADD) can trigger proapoptotic autophagy in non-small cell lung cancer (NSCLC). While the potential ubiquitin-protein ligase (E3) against TRADD is not well deciphered.

UbiBrowser was used to predict the potential E3 ubiquitin ligase to bind with TRADD. Co-immunoprecipitation was performed in HEK293T cells co-transfected with Myc-PELI3, Flag-TRADD, or HA-Ub plasmids. Increasing doses of Myc-PELI3 were transfected into HCC827 and A549 cells, and the relative expression of TRADD was detected. Cycloheximide chase assay was performed in A549 cells transfected with Myc-PELI3 plasmids, and the stability of TRADD was revealed. CCK-8 assay was performed in A549 and HCC827 cells incubated with increasing doses of Mebendazole. The expression of TRADD and PELI3 after Mebendazole incubation was assayed with Western Blot and RT-PCR. The potential E3 ubiquitin ligase of PELI3 was predicted by the UbiBrowser platform, and the binding of PELI3 with TRADD was testified in HEK293T cells co-transfected with Myc-PELI3 and Flag-TRADD plasmids.

PELI3 overexpression diminished the relative protein expression of TRADD, while not affecting the relative mRNA expression in both A549 and HCC827 cells. Cycloheximide assay and following HA-Ub detection demonstrated that PELI3 decreased the protein stability of TRADD by inducing polyubiquitination. Mebendazole inhibited the viability of HCC827 and A549 cells with diminished expression of PELI3 and increased expression of TRADD.

PELI3 can function as an E3 ubiquitin ligase to ubiquitinate TRADD, and Mebendazole might be a promising drug to affect PELI3 expression in NSCLC.