# Hypoxia-induced USP13 expression drives ferroptosis resistance and tumor immune evasion in hepatocellular carcinoma through the stabilization of ACLY

## TL;DR

This study shows that high USP13 levels in liver cancer help tumors resist treatment and avoid immune attacks, suggesting USP13 could be a new target for therapy.

## Contribution

The study identifies USP13 as a novel driver of ferroptosis resistance and immune evasion in hepatocellular carcinoma.

## Key findings

- High USP13 expression correlates with poor prognosis and reduced CD8+ T cell infiltration in hepatocellular carcinoma.
- Pharmacological inhibition of USP13 reduces tumor growth, promotes ferroptosis, and enhances T cell-mediated cytotoxicity.
- USP13 stabilizes ACLY protein under hypoxia via HIF-1α, contributing to tumor progression.

## Abstract

Hepatocellular carcinoma (HCC) is an aggressive liver cancer with high recurrence and poor prognosis. This study aims to explore USP13’s role in HCC progression and assess its potential as a therapeutic target to induce ferroptosis and enhance immune response. HCC patient-derived organoids (PDOs), HCC cell lines and animal models were utilized to evaluate the anti-cancer responses of USP13 inhibition. We analyzed the correlation of USP13 expression and immune cell infiltration using single-cell RNA sequencing, flow cytometry analysis. A USP13 inhibitor, 2-Methoxyestradiol (2-Met), was used to evaluate its therapeutic efficacy. USP13 was found to be highly expressed in HCC tissues and was correlated with poor prognosis. Single-cell RNA sequencing analysis indicated that high expression of USP13 in HCC cells was associated with decreased enrichment of CD8 + T cells in the tumor microenvironment (TME). Targeting USP13 reduced HCC cell proliferation, stemness, and cholesterol metabolism while promoting ferroptosis and enhancing T cell-mediated cytotoxicity. Mechanistically, USP13 stabilized ACLY via inhibiting the K48-specific poly-ubiquitination process on ACLY protein at the K726 site. Under hypoxia condition, HIF-1α upregulates the transcription of USP13 by binding to its promoter region, which stabilizes ACLY protein. Overall, this research reveals that hypoxia-induced USP13 expression drives ferroptosis resistance and tumor immune evasion in hepatocellular carcinoma through the stabilization of ACLY. Pharmacological inhibition or knockdown of USP13 impedes HCC progression, induces ferroptosis, and enhances T cell-mediated cytotoxic effects. These results highlight that USP13 could be a promising therapeutic target for HCC.