20.109(F09):TR Purple

Engineering an Adenovirus Selectively Targeting Pancreatic Cancer Cells

Rachael Holmes & Sylvie Polsky

Research Problem and Goals

Engineer a non-replicating adenovirus vector that uses phage display to selectively infect cancerous pancreatic cells. The virus will encode an immunotoxin or a protein that will inhibit proliferation and cause apoptosis in cancer cells. The virus will also encode a reporter gene such as EGFP to enable visualization of cells that the virus is infecting, and determine if the virus is successfully targeting pancreatic cancer cells.

References

• Bausch D et al. Plectin-1 is a Biomarker of Malignant Pancreatic Intraductal Papillary Mucinous Neoplasms. Journal of Gastrointestinal Surgery 2009; 13:1948-1954 Abstract Full Text PDF

• Bischoff JR et al. An adenovirus mutant that replicates selectively in p53-deficient human tumor cells. Science 1996; 274:373-376 Abstract Full Text PDF

The human adenovirus E1B gene encodes a protein that deactivates p53, the tumor suppressor protein. The study shows that an adenovirus mutant lacking a functional E1B was able to selectively replicate in and destroy tumor cells that had a defective p53 without affecting normal cells with a normally functioning p53.

• Ghosh D, Barry MA. Selection of Muscle-Binding Peptides from Context-Specific Peptide-Presenting Phage Libraries for Adenoviral Vector Targeting. Journal of Virology 2005; 79:13667–13672 Abstract Full Text PDF

• Hezel AF et al. Genetics and biology of pancreatic ductal adenocarcinoma. Genes & Developement 2006; 20:1218-1249 Abstract Full Text PDF

• Kelly KA et al. Targeted Nanoparticles for Imaging Incipient Pancreatic Ductal Adenocarcinoma. PLoS Med 2008; 5:e85 Abstract Full Text PDF

• Liu X et al. Novel strategies to augment genetically delivered immunotoxin molecular therapy for cancer therapy. Cancer Gene Therapy 2009; 16:861–872 Abstract Full Text PDF

Immunotoxin therapy enables selective targeting of cytotoxins to tumor cells with minimal effect of normal cells. The tumor cells were targeted by their expression of a receptor (Her-1/neu)not expressed on normal cells. A conditionally replicative adenovirus vector along with a virus encoding an immunotoxin were used to express an immunotoxin gene in cancerous cells. The study demonstrated significant tumor growth suppression.

• Michelfeldera S, Trepela M. Adeno-Associated Viral Vectors and Their Redirection to Cell-Type Specific Receptors. Advances in Genetics 2009; 67:29-60 Abstract Figures/Tables

Adeno-associated virus (AAV) has been discovered to be a useful platform for vector design because of its low frequency of random integration into the genome and the moderate illicited immune response. These AAV vectors selectively target cells of interest by identifying peptides mediating binding to the desired cell type through random phage display library screening and subsequently introducing these peptides into an AAV capsid region critical for receptor binding.

• Nicol CG et al. Use of in vivo phage display to engineer novel adenoviruses for targeted delivery to the cardiac vasculature. FEBS Letters 2009; 583:2100-2107 Abstract Full Text PDF

• Pereboev A, Pereboeva L, Curiel DT. Phage Display of Adenovirus Type 5 Fiber Knob as a Tool for Specific Ligand Selection and Validation. Journal of Virology 2001; 75:7107-7113 Abstract Full Text PDF

• Ravet E et al. Using lentiviral vectors for efficient pancreatic cancer gene therapy. Cancer Gene Therapy 2009 Abstract Full Text PDF

• Wang W et al. Selective targeting of HPV-16 E6/E7 in cervical cancer cells with a potent oncolytic adenovirus and its enhanced effect with radiotherapy in vitro and vivo. Cancer Letters 2009 Abstract Full Text PDF

A novel E1A-mutant adenovirus (M6) with antisense HPV16 E6 E7 DNA inserted into the deleted 6.7 K/gp19 K region of E3 was discovered. It was found that M6 was competent to selectively replicate in cervical cancer cells. In addition, infection of M6 was able to inhibit the expression of HPV16 E6 and E7 oncogenes and induce apoptosis of HPV16-positive cervical cancer cells. Experiments showed that treatment with M6 in combination with radiotherapy was superior to treatment by Adv5/dE1A plus radiation or M6 alone.