Evaluation of chemotherapy with nanosomal paclitaxel and gene therapy expressing apoptosis-inducing proteins in the management of spontaneous canine mammary neoplasm

Abstract

Mammary gland tumours are the second most common neoplasm representing about 40-50% of all neoplasm after skin tumour, but the majority of these tumours occur in intact/ non spaying female dogs. Surgical excision of the benign tumour is the standard treatment of canine mammary tumours. Chemotherapy is the choice of treatment if the tumour is malignant or shows evidence of invasion into lymph or blood vessels, however, they showed different side effects and their success rate is varied. Taxanes are now the most promising anti-cancer drugs with little side effects. Gene therapy expressing apoptosis-inducing proteins have ability to kill cancer cells while sparing normal cells. The present study was conducted for exploring the oncolytic effect of viral gene therapy expressing apoptosis-inducing proteins construct (ns1 +vp3), nanosomal paclitaxel as chemotherapeutic agent and surgical therapy in the management of spontaneous canine mammary tumours. Chemotherapy (nanosomal paclitaxel) (n=10), viral gene construct (ns1 +vp3) (n=10) and surgical therapy (n=10) were used in 30 female dogs of different breeds having different types of spontaneous mammary tumours. Chemotherapeutic drug and viral gene construct (ns1 +vp3) induced apoptosis in canine mammary neoplasms were studied using fluorescent activated cell sorting analysis. However, apoptotic percentage was significantly higher in chemotherapeutic group than viral gene construct therapy. No major side effects were observed in any groups. Matrix metalloproteinase-2 was found as an important prognostic tool in the management of canine mammary tumours. In conclusion, chemotherapy with nanosomal paclitaxel proved better than viral gene construct (ns1 +vp3) in the treatment of canine mammary neoplasm.