Expression of the Anti-apoptotic Factors Bcl-2 and Survivin in Canine Vascular Tumours

SummaryTo investigate whether anti-apoptotic factors play a role in the malignant growth of canine haemangiosarcomas (HSAs), 83 HSAs and 22 haemangiomas were examined immunohistochemically for bcl-2 and survivin expression. Additionally, bcl-2 and survivin mRNA expression was quantified by semiquantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunolabelling for bcl-2 was observed in 50 of the 83 HSA samples (60.2%) but in none of the haemangiomas. The average survivin positive index was 24.7% in the HSAs and 0.6% in the haemangiomas. In contrast to the high average value for survivin mRNA expression, which was approximately six times that for the haemangiomas, no significant difference was observed between HSAs and haemangiomas for the average bcl-2 mRNA expression level. The discrepancy between bcl-2 mRNA and bcl-2 protein expression requires further investigation, but the results suggest that malignant proliferation in canine HSAs is associated with bcl-2 and survivin expression.