Cytogenetic and tumour suppressor gene studies on feline soft tissue tumours

Soft tissue tumours represent a heterogeneous group of mesenchymal tumours including e.g. fibrosarcomas, malignant fibrous histiocytomas (MFH) lipomas and neurofibrosarcomas. Our cytogenetic analyses of such tumour types have led to the observation of recurrent types of numerical and structural chromosomal alterations including rearrangements like translocations. Despite the apparently nonrandom and recurrent observation of several anomalies, the detection of a strictly specific anomaly in fibrosarcomas and malignant fibrous histiocytomas remains often problematic and the karyotypic appearance is very heterogeneous. Lipomas tended to the occurence of recurrent simple rearrangements. The same patients were subjected to tumour suppressor gene analyses in the genes coding for p53, p21 WAF1, p27 kip1 and p16 MTS1/INK4. We observed mutations in p53, but not in p21 WAF1, p27 kip1 and p16 MTS1/INK4. The p53 mutations were five point mutations (two in exon 5, two in exon 7 and one in exon 8) in thirty investigated fibrosarcomas and one point mutation (in exon 7) in fifteen MFHs.