Study Identifies DNA Polymerase Kappa's Role in Cisplatin Resistance in Cancer Cells
Researchers found that DNA polymerase kappa (Pol κ) helps cancer cells resist cisplatin, a common chemotherapy drug, by stabilizing stalled DNA replication forks through protein interactions rather than direct drug bypass. The study, conducted in head and neck squamous carcinoma cells, identified two critical molecular axes involving Pol κ that protect cells from cisplatin-induced damage. This discovery could lead to new therapeutic strategies by targeting Pol κ to improve cisplatin effectiveness against advanced head and neck cancers.
A new study published on bioRxiv reveals that DNA polymerase kappa (Pol κ) plays a previously underappreciated role in cisplatin resistance in cancer cells. Rather than directly bypassing cisplatin-induced DNA damage, Pol κ functions through two distinct protein interaction networks: one involving PCNA and Pol δ that facilitates cell proliferation, and another involving PCNA and USP18 that stabilizes DNA repair pathways and protects replication forks. The research demonstrates that in cisplatin-resistant cells, Pol κ recruits a deubiquitinase enzyme (USP18) that reduces protein degradation, allowing cancer cells to maintain cellular stability under chemotherapy stress. The findings suggest that Pol κ is non-essential for normal cell function, making it an attractive therapeutic target. The authors propose that blocking Pol κ could enhance cisplatin's effectiveness against advanced head and neck squamous carcinoma.
What's missing
The study's limitations are not detailed in the abstract provided, including whether findings were validated in animal models or clinical samples beyond cell culture, the generalizability to other cancer types, and potential off-target effects of targeting Pol κ in normal tissues.
What different sources said
- bioRxivCenter
PCNA-Pol κ-Polδ /USP18 axes stabilize replication fork and restart to reduce cisplatin cytotoxicity
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