TONSL Promotes Hepatocellular Carcinoma Progression by Inhibiting Apoptosis Through Homologous Recombination Repair.

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Hepatocellular carcinoma (HCC) is aggressive with poor outcomes, often linked to chromosome 8q amplification.
• The Tonsoku-like DNA repair protein (TONSL) gene on 8q repairs DNA double-strand breaks, but its role in HCC is unclear.

Purpose of the Study:

• Investigate the biological significance of TONSL in HCC progression.
• Determine TONSL's role in DNA repair, apoptosis, and response to therapy in HCC.

Main Methods:

• Analysis of public datasets and clinical HCC specimens.
• Functional assays including gene knockout and cell growth/apoptosis assessments.
• Xenograft mouse models to evaluate tumor growth in vivo.

Main Results:

• TONSL expression is elevated in HCC tumors and correlates with copy number variations and poor patient outcomes.
• TONSL knockout reduces HCC cell growth, increases apoptosis, and impairs RAD51 recruitment for homologous recombination repair.
• TONSL-knockout HCC cells exhibit increased sensitivity to PARP inhibitors, and tumors show reduced growth in vivo.

Conclusions:

• TONSL promotes HCC development by supporting DNA repair and inhibiting apoptosis.
• Elevated TONSL expression is a marker of HCC aggressiveness and poor prognosis.
• TONSL is a potential therapeutic target and biomarker for HCC.