Chemoresistance contributes to the majority of deaths in women with ovarian cancer (OC). Altered DNA repair and metabolic signaling is implicated in mediating therapeutic resistance. DNA damage checkpoint kinase 1 (CHK1) integrates cell cycle and DNA repair in replicating cells, and its inhibition causes replication stress, repair deficiency and cell cycle dysregulation. We observed elevated Poly-ADP-ribosylation (PAR) of proteins (PARylation) and subsequent decrease in cellular NAD⁺ levels in OC cells treated with the CHK1 inhibitor prexasertib, indicating activation of NAD⁺ dependent DNA repair enzymes poly-ADP-ribose polymerases (PARP1/2). While multiple PARP inhibitors are in clinical use in treating OC, tumor resistance to these drugs is highly imminent. We reasoned that inhibition of dePARylation by targeting Poly (ADP-ribose) glycohydrolase (PARG) would disrupt metabolic and DNA repair crosstalk to overcome chemoresistance. Although PARG inhibition (PARGi) trapped PARylation of the proteins and activated CHK1, it did not cause any significant OC cell death. However, OC cells deficient in CHK1 were hypersensitive to PARGi, suggesting a role for metabolic and DNA repair crosstalk in protection of OC cells. Correspondingly, OC cells treated with a combination of CHK1 and PARG inhibitors exhibited excessive replication stress-mediated DNA lesions, cell cycle dysregulation, and mitotic catastrophe compared to individual drugs. Interestingly, increased PARylation observed in combination treatment resulted in depletion of NAD⁺ levels. These decreased NAD⁺ levels were also paralleled with reduced aldehyde dehydrogenase (ALDH) activity, which requires NAD⁺ to maintain cancer stem cells. Furthermore, prexasertib and PARGi combinations exhibited synergistic cell death in OC cells, including an isogenic chemoresistant cell line and 3D organoid models of primary patient-derived OC cell lines. Collectively, our data highlight a novel crosstalk between metabolism and DNA repair involving replication stress and NAD⁺-dependent PARylation, and suggest a novel combination therapy of CHK1 and PARG inhibitors to overcome chemoresistance in OC.

Background: High-risk human papillomaviruses (HPV-HR) are implicated in more than 99% of cervical/vaginal malignancies. Despite this strong association, current guidelines recommend PET/CT imaging over HPV-HR DNA testing as the standard prognostic tool following definitive therapy. This retrospective, single-institution, proof-of-concept study evaluated HPV-HR DNA testing as a potential alternative to PET/CT imaging for posttreatment surveillance in cervical and vaginal cancers. Methods: Female patients with cervical or vaginal cancer treated between 2010 and 2023 at our institution were retrospectively analyzed. Eligible patients had complete documentation of pre- and posttreatment PET/CT imaging and HPV-HR DNA testing. Of more than 100 patients identified, only 53 met the inclusion criteria, and both radical hysterectomy and chemoradiation patients were included. Statistical analyses, including sensitivity, specificity, and predictive values, were conducted using Stata, with significance set at 0.05. Results: Posttreatment HPV-HR DNA testing demonstrated a superior sensitivity (92.31%) and negative predictive value (97.44% NPV) compared with PET/CT imaging (76.92% sensitivity and 92.31% NPV). Although PET/CT imaging maintained higher specificity over HPV-HR DNA testing (100% vs. 95%) and positive predictive value (100% vs. 85.71%), HPV-HR DNA testing offers a more sensitive and cost-effective method for identifying patients requiring further evaluation. Conclusions: HPV-HR DNA testing is a promising, cost-effective surveillance tool with higher sensitivity and NPV than PET/CT. Its clinical use may reduce PET/CT need, improve safety, and lower costs and require further validation. Impact: HPV-HR DNA testing offers a cost-effective alternative to PET/CT, reducing costs, unnecessary imaging, and improving accessibility.

The human papilloma virus (HPV) high-risk variants (HPV-HR) such as HPV16 and HPV18 are responsible for most HPV related cancers, including anogenital and head and neck cancers. Here, we present two patients with HPV-HR-associated gynecological malignancies who, after failing radiation therapy, were treated with experimental salvage immunotherapy regimen resulting in complete, durable responses in both patients. Each patient was diagnosed with recurrent, radiation-refractory, HPV-HR positive, squamous cell carcinoma of the lower genital tract. Patient A was a 90-year-old, African American, with metastatic vulvar cancer to the right inguinal-femoral triangle and pulmonary metastases. Patient B was a 41-year-old, Caucasian, with a central-recurrence of cervix cancer. Each patient received at least two intratumoral quadrivalent HPV-L1 vaccine (Gardasil™) injections and daily topical TLR-7 agonist (imiquimod) to the tumor surface 2 weeks apart. This combination of intratumoral vaccinations and topical TLR-7 agonist produced unexpected complete resolution of disease in both patients. The importance of radiation therapy, despite being considered a treatment failure by current definitions, cannot be understated. Radiation therapy appears to have offered a therapeutic immune advantage by modifying the tumor microenvironment. This immune protocol has potential to help patients with advanced HPV-HR-related malignancies previously considered incurable.

Introduction: Uterine carcinosarcoma is an aggressive gynecologic malignancy that accounts for 5% of all gynecological malignancies. There is a disproportion in its incidence and mortality among different races. This study describes demographic and clinicopathological factors and racial disparities affecting the survival of patients with uterine carcinosarcoma. Methods: Data on uterine carcinosarcoma patients were obtained from the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2020. Results: Of the 11,338 patients identified, the median age at diagnosis was 68 years, and the five-year cause-specific survival (CSS) rate was 38.7%. for all races. Compared with Asian patients (39.5%, 95% CI, 36.0–43.4%), Hispanic patients (39.4%, 95% CI, 36.5–42.5%), and White patients (37.9%, 95% CI, 36.7–39.2%), Black patients accounted for 21% of the patients and had a significantly lower 5-year CSS (95% CI, 27.2–31.2%). The CSS rates were 84.4% (95% CI, 83.3–85.6%) for localized tumors, 68.5% (95% CI, 66.9–70.1%) for regional tumors, and 39.0% (95% CI, 36.9–41.2%) for distant tumors. Multimodal treatment involving chemotherapy, surgery, and radiation improved the overall one- and five-year survival rates by 88.2% (95% CI, 87.0–89.5%) and 52.8% (95% CI, 50.7–55.1%), respectively, across all disease stages. Multivariate analysis identified age >60 years, Black race, tumor size >4 cm, and distant metastases as independent risk factors for mortality (p < 0.0001). Conclusions: This large database study presents the most up-to-date epidemiological information regarding cases of uterine carcinosarcoma. The findings suggest that a combination of surgery, chemotherapy, and radiation may be most efficacious in treating this malignancy, especially in patients with distant disease.