Heat Shock Protein Expression and Implications in Spontaneous Animal Tumors: Veterinary and Comparative Aspects

Heat shock proteins (HSP) play a fundamental role in the maintenance of cellular homeostasis, under both physiological and stress conditions, by acting as molecular chaperones in protein folding, intracellular transport and degradation. HSP are also implicated in the hallmarks of cancer from proliferation, impaired apoptosis and sustained angiogenesis to invasion and metastasis. Altered HSP levels have been observed in a variety of human neoplasms and such abnormal expression may contribute to poor prognosis and drug resistance. Therefore, these molecular chaperones represent attractive targets for anti-cancer therapy. A growing number of studies in veterinary medicine have also demonstrated the presence of altered HSP expression in spontaneous animal tumors, especially canine cancer, and the study of carcinogenesis and the role of HSP in animal models represent an additional source of information for clinical cancer research. This chapter briefly reviews the current knowledge on HSP expression and implications in spontaneous animal neoplasms, and the advances in understanding of the therapeutic opportunities offered by HSP-based anti-cancer therapies in veterinary and comparative oncology.