Assessing Autophagy Activation in Advanced Ovarian Cancer Using Ascitic Fluid: A Feasibility Study.

Introduction: Autophagy plays a role in chemotherapy resistance by facilitating cell survival under stress conditions in many malignancies, including ovarian cancers. The use of ascitic fluid to study autophagy biomarkers is an emerging approach, with potential advantages over tissue-based studies in cancer research. This study aimed to standardize reproducible laboratory methods for detecting and quantifying autophagy biomarkers in the ascitic fluid of ovarian cancer patients.

Methods: Ascitic fluid samples were analyzed using three techniques in 30 ovarian cancer patients: (1) enzyme-linked immunosorbent assay (ELISA) for Beclin 1, p62/sequestosome 1 (p62/sqstm1), and synaptosomal associated protein 23 (SNAP 23); (2) immunocytochemistry (ICC) for Syntaxin 17 and vesicle-associated membrane protein 8 (VAMP 8) localization; and (3) flow cytometry for epithelial cell identification and Annexin V expression assessment.

Results: We standardized autophagy marker expression in ascitic fluid from ovarian cancer patients. Although the sample size was small, preliminary differences in biomarker expression were observed across disease phases. Beclin 1 levels were elevated in relapsed patients compared to newly diagnosed patients, suggesting potential autophagy activation. Further validation with larger cohorts is needed. ICC revealed heterogeneous expression of Syntaxin 17 and VAMP 8, with variations observed across patient samples. Flow cytometry identified tumor epithelial cells and Annexin V (pro-apoptotic marker) expression in these cells.

Conclusion: Techniques for analyzing autophagy markers in ascitic fluid were successfully standardized. The ascitic fluid analysis offers a non-invasive, accessible method for studying ovarian cancer biology, potentially enhancing understanding and management. Further research with larger cohorts and integration of traditional biomarkers could improve clinical utility in ovarian cancer.