TGM2 Regulates Radiosensitivity via POGZ ‐Mediated Repair of DNA Double‐Strand Breaks in Cervical Cancer

ABSTRACT

The high capacity of cancer cells for DNA damage repair constitutes a critical factor contributing to their radioresistance. Previous studies have demonstrated that aberrant expression of transglutaminase 2 (TGM2) is linked to treatment resistance. However, the role of TGM2 in cervical cancer radiosensitivity and its underlying mechanisms remain unclear. In this study, we found that TGM2 was significantly upregulated in radioresistant cervical cancer cells and tissues. TGM2 knockdown significantly enhanced the radiosensitivity of cervical cancer cells, while TGM2 overexpression conferred radioresistance. TGM2 depletion exacerbated ionizing radiation (IR)‐induced DNA double‐strand breaks (DSBs). Mechanistically, IR triggered the nuclear translocation of TGM2, where it physically interacted with POGO transposable element derived with ZNF domain protein (POGZ) and upregulated POGZ protein levels. TGM2 knockdown impaired BRCA1 recruitment to DSB sites, phenocopying POGZ depletion effects. Rescue experiments demonstrated that POGZ knockdown reversed the radioresistance and reduction in DNA DSBs caused by TGM2 overexpression. Subcutaneous xenograft mouse models further verified these findings and the regulatory role of TGM2 in cervical cancer radiosensitivity in vivo. Together, our results demonstrated that TGM2 regulates radiosensitivity by POGZ‐mediated DNA DSBs repair, providing a novel strategy for increasing cervical cancer radiosensitivity.