As the technique increases the visibility of the cancer cells and makes it more accessible to treatment, it might allow precise monitoring of how certain anti-cancer agents work. 'In tumor-bearing mice, we show that this hybrid virus can target tumors systemically to deliver an imaging or therapeutic gene. The signal is specific only to tumors, so one can monitor drug effectiveness at the molecular level,' said Renata Pasqualini, the co-leader of the study.
The hybrid virus was created by a culmination of the biological characteristics and genetic components of an animal virus. The new hybrid virus named as AAV phage or AAVP can be used as a vehicle for delivery of specific genes targeted at tumors in mice produced through appropriate techniques.
This technique of genetically marking a tumor could eventually lead to a strategy for detection on a clinic-ready body scanner. The unique ability of the hybrid virus to deliver genes or other agents into the cells in addition to targeting specific tissues represents a distinct advantage. What surprised the researchers is that the hybrid viruses retained the properties of the parental viruses, from which they were derived.
'This is only a proof-of-concept, and although we have yet to translate these hybrid viruses for use in humans, we hope that this new system will have future clinical applications. In addition to the obvious biological interest, when the vector is refined for patient use, it could perhaps help us diagnose, monitor and treat human tumors more accurately,' said Wadih Arap, co-leader of the study.
As the next step, the researchers intend to design studies to evaluate the safety and efficacy of the hybrid vectors in animal models designed to mimic human models of cancer. If successful results are obtained, the research would concentrate on ways and means to adapt and optimize the AAVP-based tumor targeting for use in cancer patients.
The researchers referred to the new technique as a 'theragnostic' approach. In other words, it is a combination of the diagnostic and therapeutic modalities. With research such as this offering endless hope in the diagnosis and treatment of cancer, a cure for the disease is not very far.