EXPRESSION OF BCL2, P53 AND KI67 IN SPONTANEOUS CANINE OSTEOBLASTIC OSTEOSARCOMA: A PRELIMINARY STUDY

Osteosarcoma is the most primary malignancy of bone. A comprehensive understanding of biomolecular mechanisms of osteosarcoma is essential to improve the early diagnoses and prognosis of patients especially through tumor-targeted therapies. Autophagy is a self-degradative process that is important for balancing the cellular energy levels in development and in response to nutrient stress and to removed proteins, damaged organelles, eliminating intracellular pathogens and to promotes cellular senescence and many other processes like preventing diseases such as cancer. The present preliminary study was to evaluate the expression of different biomarkers of cell proliferation and autophagy including bcl2, p53 and Ki-67 by immunohistochemistry. Bcl2 is an intracellular membrane protein which prevents apoptotic cell death. Overexpression of bcl2 can block p53 activity and then induced apoptosis. Bcl2 overexpression was described in many different premalignant and malignant lesions but never in primary canine osteosarcoma. We investigated first 10 cases of primitive canine osteosarcoma from the last four year retrieved from our Departments. In this preliminary study we consider only cases of canine osteoblastic osteosarcoma classified on the basis of WHO international classification of bone and joint tumors. Bcl2 immunostaining showed an increasing expression in all cases investigated, not always associated with increasing of p53 and Ki67 and no statistical association was seen between p53, bcl2 and Ki67. In conclusion we believe that evaluation of Bcl2 expression may be used as a diagnostic marker but its role as a prognostic marker needs to be further investigate.