The evening session began with a Skype presentation by Dr Luigi Auriscchio. He spoke about the novel immunotherapeutic approaches for canine lymphoma his companies, Evvivax and Takis Biotech, have developed. Evvivax uses a genetic vaccine targeting dog telomerase reverse transcriptase (dTERT) based on adenovirus DNA electro-gene-transfer technology that induces a strong cell-mediated immune response against tumour antigen. It increases overall survival in dogs with B cell lymphoma when used in conjunction with COP chemotherapy. Owing to similarities between canine and human gene expression, he went on to conclude that this could be a possible area to explore in the human arena.
Dr Imelda McGonnell of the RVC continued the evening session by presenting work conducted by her PhD student, Lisa Pritchard. The talk focused on the role of the myoepithelium in canine mammary carcinomas. The function of myoepithelial (ME) cells is to maintain epithelial cell polarity, elicit contractility during lactation, and produce basement membranes. Human tumours tend not to have ME cells, whereas in dogs they are still present – and interestingly, unlike human mammary tumours, 60% of mammary tumours in canines are benign. In rare adenoid cyst carcinomas occurring in humans, ME cells are still intact and the cancer rarely metastasises. Dr McGonnell suggested that ME cells could play a role as a metastatic inhibitor and a tumour suppressor. Ms Pritchard’s research went on to ascertain whether, when present in dogs, malignant tumours lose their ME cells. P63 was used as a marker for ME cells and it was discovered that as malignancy increased, the number of ME cells decreased. This begs the question, where do they go? Further research found that they were not undergoing apoptosis, not undertaking mesenchymal to epithelial transition, and not changing into fully differentiated epithelia. This question has not yet been answered, but the lack of ME cells in more malignant tumours further aids the theory that they act as tumour suppressors. Dr McGonnell emphasised the importance of looking at the differences between canine and human cancers as opposed to simply using them as models. If key differences can be found, there is a possibility that treatment in the human arena could be enhanced.
Picture: © Professor Oliver Garden