A Novel Assay to Assess Primary Human Cancer Infectibility by Replication-Selective Oncolytic Adenoviruses

• Published in: Clinical cancer research 2005-01, Vol.11 (1), p.351-360
• Main Authors: YAOHE WANG, THORNE, Stephen, HANOCK, Joseph, FRANCIS, Jennelle, AU, Tina, REID, Tony, LEMOINE, Nick, KIRN, David, HALLDEN, Gunnel
• Format: Article
• Language: English
• Subjects: adenocarcinoma; Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Adenoviridae - genetics; Adenovirus; Adenovirus E1A Proteins - biosynthesis; Antineoplastic agents; Biological and medical sciences; Cell Line, Tumor; Coxsackie and Adenovirus Receptor-Like Membrane Protein; Coxsackievirus; Cytopathogenic Effect, Viral; deletion mutants; ex vivo; Female; Gene Expression Regulation, Viral; gene therapy; Genetic Techniques; Humans; Immunohistochemistry; Integrin alphaV - metabolism; Male; Medical sciences; Mutation; Neoplasms - metabolism; Pharmacology. Drug treatments; preclinical models; Proliferating Cell Nuclear Antigen - metabolism; Receptors, Virus - metabolism; Time Factors; Tumor Cells, Cultured; Virus Replication
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.351.11.1

Purpose: Replication-selective oncolytic adenoviruses hold promise for cancer treatment, but the predictive use of cell lines, dissociated tumor tissue, and animal models for efficacy against primary cancers are unclear. To further evaluate cytotoxicity and the potential for efficacy of replication-competent adenoviruses we therefore developed a novel methodology using primary human cancer specimens ex vivo ; ovarian, colon, rectal, and breast carcinomas were included. Experimental Design: Tissue culture conditions were developed to maintain viability of adenocarcinomas ex vivo for 48 hours postsurgery. Explants were infected by replication-competent (wild type 5 and E1A mutant dl 922-947) and replication-defective ( dl 312) adenoviruses; early ( E1A ) and late (hexon) viral gene expression, α v integrins, coxsackievirus and adenovirus receptor (CAR) and tissue viability were assessed by immunohistochemistry and histopathology. Viral replication was verified by replication assays on selected samples. Results: Viral gene expression varied dramatically among cancer specimens ( n = 41). With Ad5 , hexon expression was high in 8 of 11 tested specimens, whereas E1A levels were detectable in 16 of 27 tumor explants. Viral gene expression, distribution, and cytopathic effects were greater postinfection with dl 922-947. Specimens that supported early gene expression ( E1A ) also supported viral replication in 13 of 14 tested cases, determined by recovery of infectious units. As predicted, the replication-defective adenovirus dl 312 was not associated with viral gene expression. Conclusions: Primary human tumor tissue remained viable when cultured ex vivo enabling evaluation of viral mutants in tissue with intact morphology. This assay may have great use in determining treatment-sensitive cancers and assess specific oncolytic mutants in individual cases.