Abstract | OBJECTIVE: We propose that metastatic epithelial ovarian cancer (EOC) is a potential therapeutic target for the oncolytic agent, Myxoma virus (MYXV). METHODS: Primary EOC cells were isolated from patient ascites and cultured as adherent cells or in suspension using Ultra Low-Attachment dishes. MYXV expressing green fluorescent protein was used to infect cells and spheroids. Infection was monitored by fluorescence microscopy, viral titering and immunoblotting for M-T7 and M130 virus protein expression, and cell viability by alamarBlue assay. Akti-1/2 (5 μM) and rapamycin (20 nM) were used to assay the role of PI3K-AKT signaling in mediating MYXV infection. RESULTS:
Ascites-derived EOC cells grown in adherent culture are effectively killed by MYXV infection. EOC cells grown in suspension to form three-dimensional EOC spheroids readily permit MYXV entry into cells, yet are protected from the cytopathic effects of late MYXV infection. Upon reattachment (to model secondary metastasis), EOC spheroids are re-sensitized to MYXV-mediated oncolysis. The critical determinant that facilitates efficient MYXV infection is the presence of an activated PI3K-AKT signaling pathway. Treatment with the specific AKT inhibitor Akti-1/2 reduces infection of monolayer EOC cells and spheroids. Direct infection of freshly-collected ascites demonstrated that 54.5% of patient samples were sensitive to MYXV-mediated oncolytic cell killing. We also demonstrate that factor(s) present in ascites may negatively impact MYXV infection and oncolysis of EOC cells, which may be due to a down-regulation in endogenous AKT activity. CONCLUSIONS: Differential activity of AKT serves as the mechanistic basis for regulating MYXV-mediated oncolysis of EOC spheroids during key steps of the metastatic program. In addition, we provide the first evidence that MYXV oncolytic therapy may be efficacious for a significant proportion of ovarian cancer patients with metastatic disease.
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Authors | Rohann J M Correa, Monica Komar, Jessica G K Tong, Milani Sivapragasam, Masmudur M Rahman, Grant McFadden, Gabriel E Dimattia, Trevor G Shepherd |
Journal | Gynecologic oncology
(Gynecol Oncol)
Vol. 125
Issue 2
Pg. 441-50
(May 2012)
ISSN: 1095-6859 [Electronic] United States |
PMID | 22306204
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2012 Elsevier Inc. All rights reserved. |
Chemical References |
- Green Fluorescent Proteins
- Phosphatidylinositol 3-Kinases
- Oncogene Protein v-akt
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Topics |
- Ascites
(pathology)
- Carcinoma, Ovarian Epithelial
- Female
- Green Fluorescent Proteins
(biosynthesis, genetics)
- Humans
- Microscopy, Fluorescence
(methods)
- Myxoma virus
(genetics, metabolism, physiology)
- Neoplasms, Glandular and Epithelial
(enzymology, therapy, virology)
- Oncogene Protein v-akt
(metabolism)
- Oncolytic Virotherapy
(methods)
- Ovarian Neoplasms
(enzymology, therapy, virology)
- Phosphatidylinositol 3-Kinases
(metabolism)
- Spheroids, Cellular
(pathology)
- Tumor Cells, Cultured
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