Cross‑validation of genes potentially associated with neoadjuvant chemotherapy and platinum‑based chemoresistance in epithelial ovarian carcinoma

Novel players in the development of chemoresistance in ovarian cancer: ovarian cancer stem cells, non-coding RNA and nuclear receptors

Ovarian cancer (OC) ranks as the fifth leading factor for female mortality globally, with a substantial burden of new cases and mortality recorded annually. Survival rates vary significantly based on the stage of diagnosis, with advanced stages posing significant challenges to treatment. OC is primarily categorized as epithelial, constituting approximately 90% of cases, and correct staging is essential for tailored treatment. The debulking followed by chemotherapy is the prevailing treatment, involving platinum-based drugs in combination with taxanes. However, the efficacy of chemotherapy is hindered by the development of chemoresistance, both acquired during treatment (acquired chemoresistance) and intrinsic to the patient (intrinsic chemoresistance). The emergence of chemoresistance leads to increased mortality rates, with many advanced patients experiencing disease relapse shortly after initial treatment. This review delves into the multifactorial nature of chemoresistance in OC, addressing mechanisms involving transport systems, apoptosis, DNA repair, and ovarian cancer stem cells (OCSCs). While previous research has identified genes associated with these mechanisms, the regulatory roles of non-coding RNA (ncRNA) and nuclear receptors in modulating gene expression to confer chemoresistance have remained poorly understood and underexplored. This comprehensive review aims to shed light on the genes linked to different chemoresistance mechanisms in OC and their intricate regulation by ncRNA and nuclear receptors. Specifically, we examine how these molecular players influence the chemoresistance mechanism. By exploring the interplay between these factors and gene expression regulation, this review seeks to provide a comprehensive mechanism driving chemoresistance in OC.

Nuclear Factor of Activated T Cells-5 Regulates Notochord Lumenogenesis in Chordate Larval Development

Osmoregulation is essential for organisms to adapt to the exterior environment and plays an important role in embryonic organogenesis. Tubular organ formation usually involves a hyperosmotic lumen environment. The mechanisms of how the cells respond and regulate lumen formation remain largely unknown. Here, we reported that the nuclear factor of activated T cells-5 (NFAT5), the only transcription factor in the NFAT family involved in the cellular responses to hypertonic stress, regulated notochord lumen formation in chordate Ciona. Ciona NFAT5 (Ci-NFAT5) was expressed in notochord, and its expression level increased during notochord lumen formation and expansion. Knockout and expression of the dominant negative of NFAT5 in Ciona embryos resulted in the failure of notochord lumen expansion. We further demonstrated that the Ci-NFAT5 transferred from the cytoplasm into nuclei in HeLa cells under the hyperosmotic medium, indicating Ci-NFAT5 can respond the hypertonicity. To reveal the underly mechanisms, we predicted potential downstream genes of Ci-NFAT5 and further validated Ci-NFAT5-interacted genes by the luciferase assay. The results showed that Ci-NFAT5 promoted SLC26A6 expression. Furthermore, expression of a transport inactivity mutant of SLC26A6 (L421P) in notochord led to the failure of lumen expansion, phenocopying that of Ci-NFAT5 knockout. These results suggest that Ci-NFAT5 regulates notochord lumen expansion via the SLC26A6 axis. Taken together, our results reveal that the chordate NFAT5 responds to hypertonic stress and regulates lumen osmotic pressure via an ion channel pathway on luminal organ formation.

Neoadjuvant Chemotherapy Versus Primary Debulking Surgery in FIGO Stage III and IV Epithelial Ovarian, Tubal or Peritoneal Cancer: A Systematic Review and Meta-Analysis

Objective: To investigate whether neoadjuvant chemotherapy (NACT) confers superior outcomes compared to primary debulking surgery (PDS) in patients with stage III and IV epithelial ovarian, tubal or peritoneal cancer as well as in patients with high tumour load. Methods: We searched the electronic databases PubMed, Cochrane Central Register of Controlled trials, and Scopus from inception to March 2021. We considered randomised controlled trials (RCTs) comparing NACT with PDS for women with epithelial ovarian cancer (EOC) stages III and IV. The primary outcomes were overall survival and progression-free survival. Secondary outcomes were optimal cytoreduction rates, peri-operative adverse events, and quality of life. Results: Six RCTs with a total of 1901 participants were included. Meta-analysis demonstrated similar overall survival (HR = 0.96, 95% CI [0.86-1.07]) and progression-free survival (HR = 0.98, 95% CI [0.89-1.08]) between NACT and PDS. Subgroup analyses did not demonstrate higher survival for stage IV patients (HR = 0.88, 95% CI [0.71-1.09]) nor for patients with metastatic lesions >5 cm (HR = 0.86, 95% CI [0.69-1.08]) treated with NACT, albeit with some uncertainty due to imprecision. Similarly, no survival benefit was observed in the subgroup of patients with metastatic lesions >10 cm (HR = 0.94, 95% CI [0.78-1.12]). NACT was associated with significantly higher rates of complete cytoreduction (RR = 2.34, 95% CI [1.48-3.71]). Severe peri-operative adverse events were less frequent in the NACT arm (RR = 0.34, 95% CI [0.16-0.72]. Conclusion: Patients with stage III and IV epithelial ovarian cancer undergoing NACT or PDS have similar overall survival. NACT is likely associated with higher rates of complete cytoreduction and lower risk of severe adverse events and peri-operative death.