Inhibition of REV3 expression induces persistent DNA damage and growth arrest in cancer cells

Area of Science:

• Molecular Biology
• Cancer Research
• DNA Repair Mechanisms

Background:

• REV3 is the catalytic subunit of DNA translesion synthesis polymerase ζ.
• REV3 inhibition enhances sensitivity to DNA-damaging agents and reduces resistance.
• The role of REV3 in cancer cell proliferation and DNA damage response requires further elucidation.

Purpose of the Study:

• To investigate the effect of REV3 depletion on the proliferation of various cancer cell lines.
• To explore the underlying mechanisms of REV3 inhibition-induced growth suppression.
• To assess the potential of REV3 as a therapeutic target in cancer treatment.

Main Methods:

• Short hairpin RNA (shRNA)-mediated depletion of REV3 expression in multiple cancer cell lines (lung, breast, mesothelioma, colon) and control cell lines.
• Assessment of colony formation, DNA damage markers (phospho-ATM, 53BP1, phospho-H2AX foci), cell cycle distribution (G1, G2/M), and senescence markers (p21, β-galactosidase activity).
• Comparison of REV3 depletion effects in p53-proficient versus p53-deficient cancer cells.

Main Results:

• REV3 depletion significantly suppressed colony formation in lung, breast, mesothelioma, and colon cancer cell lines, with minimal impact on control and normal cells.
• Inhibition of REV3 led to accumulation of persistent DNA damage and activation of the ATM-dependent DNA damage response cascade.
• p53-proficient cells exhibited G1 arrest and senescence, while p53-deficient cells showed G2/M arrest, growth inhibition, mitotic slippage, and aneuploidy.

Conclusions:

• REV3 depletion per se suppresses the growth of diverse cancer cell lines, indicating its critical role in cancer cell proliferation.
• REV3 inhibition triggers significant DNA damage and distinct cell cycle responses depending on p53 status.
• REV3 represents a promising therapeutic target for cancer, potentially as an adjunct to chemotherapy or as a monotherapy.