Characteristics of PRIMPOL knockout А549 cell response to genоtoxic stress

Abstract

Human DNA primase/polymerase PrimPol synthesizes DNA primers de novo after replication fork stalling at damaged DNA sites, contributing to DNA damage tolerance. The contribution of PrimPol in response to the various types of DNA damage is not fully understood. We obtained the lung carcinoma cells A549 with PRIMPOL knockout and characterized its response to DNA damage caused by hydrogen peroxide, methylmethanesulfonate (MMS), cisplatin, bleomycin and ionizing radiation. Knockout of PRIMPOL reduced the number of proliferating cells and cells in G2 phase after treatment with MMS, caused a more pronounced delay of cisplatin-treated cells in S phase. A significant increase in the proportion of apoptotic cells was noted in PRIMPOL-/- cells in response to ionizing radiation at a dose of 10 Gy, while the proportion of cells prone to necroptosis increased significantly in both parental and knockout cells at any radiation dose. Under conditions of oxidative stress stimulated by hydrogen peroxide, PRIMPOL knockout increased cell viability, measured by the MTT method. The data obtained indicate the involvement of PRIMPOL in modulating stress-adaptive responses to various types of genotoxic stress.