Detection of the expression of c-myc mRNA by in situ hybridization in canine lymphoma

Lymphoma malignum called also lymphosarcoma most frequently occur as neopla sm in dogs' haematopietic system. The aim of the present study was to demon strate the occurance of c-myc protooncogene expression lymphoma cells in do gs. Expression of mRNA c-myc oncogene appeared only in 3 out of 12 examined cases. The presence of hybrid particles was detected in lymphocytoma cells with partially maintained lobule structure of low malignance state, centro blastic lymphoma of medium malignance state, and lymphoblastic lymphoma of high malignance state. In the rest of the lymphoma specimens no specific si gnal after hybridization with v-myc probe, meaning the accumulation in neop lasma cells of mRNA transcribed on c-myc oncogene, matrix, was noticed. The detection of oncogene expression in neoplasma of low, medium and high mali gnance state makes suppose that its activation occurs in early stages of ly mphoma development. No associations among an expression of examined oncogen e, a type of neoplasma process, race, sex and dog age were observed.