Related Experiment Video
Updated: Jul 17, 2025
Heterotypic Three-dimensional In Vitro Modeling of Stromal-Epithelial Interactions During Ovarian Cancer Initiation and Progression
Published on: August 28, 2012
Probing the Cytotoxic Signaling Induced by Eupenifeldin in Ovarian Cancer Models
Amanda C Maldonado1, Monica A Haughan2, Manead Khin2
1Chicago Biomedical Consortium, Northwestern University, Evanston, Illinois 60208, United States.
Abstract:
High-grade serous ovarian cancer (HGSOC) is the most common and lethal ovarian cancer histotype. Lack of early detection methods, limited therapeutic agents, and low 5-year survival rate reflect the urgent need to develop new therapies. Eupenifeldin, a bistropolone, originally isolated from Eupenicillium brefeldianum, is a cytotoxic fungal metabolite. In three HSGOC cell lines (OVCAR3, OVCAR5, OVCAR8), eupenifeldin was found to have an IC50 value less than 10 nM, while 10 times higher concentrations were required for cytotoxicity in nontumorigenic fallopian tube secretory epithelial cell lines (FTSEC). An in vivo hollow fiber assay showed significant cytotoxicity in OVCAR3. Eupenifeldin significantly increased Annexin V staining in OVCAR3 and -8, but not OVCAR5. Eupenifeldin activated caspases 3/7 in OVCAR3, OVCAR5, and OVCAR8; however, cleaved PARP was only detected in OVCAR3. Quantitative proteomics performed on OVCAR3 implicated ferroptosis as the most enriched cell death pathway. However, validation experiments did not support ferroptosis as part of the cytotoxic mechanism of eupenifeldin. Autophagic flux and LC3B puncta assays found that eupenifeldin displayed weak autophagic induction in OVCAR3. Inhibition of autophagy by cotreatment with bafilomycin reduced the toxicity of eupenifeldin, supporting the idea that induction of autophagy contributes to the cytotoxic mechanism of eupenifeldin.
Insights
Eupenifeldin, a fungal metabolite, shows potent cytotoxicity against high-grade serous ovarian cancer (HGSOC) cells. Its mechanism involves inducing autophagy, offering a promising avenue for new ovarian cancer therapies.
Area of Science:
- Biochemistry
- Pharmacology
- Oncology
Background:
- High-grade serous ovarian cancer (HGSOC) is a leading cause of cancer death with limited treatment options.
- There is an urgent need for novel therapeutic agents to improve survival rates for HGSOC patients.
Purpose of the Study:
- To investigate the cytotoxic effects and underlying mechanisms of eupenifeldin, a fungal metabolite, against HGSOC.
- To evaluate eupenifeldin's potential as a new therapeutic agent for ovarian cancer.
Main Methods:
- Cytotoxicity assays (IC50) were performed on HGSOC cell lines (OVCAR3, OVCAR5, OVCAR8) and non-tumorigenic cells (FTSEC).
- In vivo hollow fiber assay, Annexin V staining, caspase activation, and PARP cleavage assays were used to assess cell death.
- Quantitative proteomics, ferroptosis assays, and autophagy flux/LC3B puncta assays were conducted to elucidate the mechanism of action.
Main Results:
- Eupenifeldin demonstrated significant cytotoxicity against HGSOC cell lines with IC50 values < 10 nM.
- While initial proteomic data suggested ferroptosis, subsequent experiments did not support this pathway.
- Eupenifeldin induced weak autophagy, and inhibiting autophagy reduced its cytotoxic effect, indicating autophagy's contribution to its mechanism.
Conclusions:
- Eupenifeldin exhibits potent and selective cytotoxicity against HGSOC cells.
- The cytotoxic mechanism of eupenifeldin involves the induction of autophagy in ovarian cancer cells.
- Eupenifeldin represents a potential novel therapeutic candidate for high-grade serous ovarian cancer.
