Cytogenetic, ras, and p53: studies in cases of canine neoplasms (hemangiopericytoma, mastocytoma, histiocytoma, chloroma)

Abstract

Four case reports of mesenchymal neoplasms showing chromosomal abnormalities are presented. In a case of hemangiopericytoma trisomy 2 and centric fusion 19;21 were present. In a mastocytoma a deleted chromosome 35 was seen. A homogeneously staining region (HSR) on chromosome 1 was detected in a histiocytoma. Trisomy 5 and monosomy 31 were observed in a case of granulocytic sarcoma (chloroma). The lack of mutations in exons 1 and 2 of oncogenes N-ras, Kras, and H-ras and exons 5, 6, 7, and 8 of tumor suppressor gene p53 in these four patients and in a larger series of investigated dogs (25 hemangiopericytomas, 12 mastocytomas, and 8 histiocytomas) is highlighted.

Mast cells and canine mast cell tumours. A review

“…Homozygous introdeletions of the Ckit gene were significant more frequent in MCTs (49%) than in normal tissues (13%), again particularly in poorly differentiated tumours (96). A chromosomal deletion of chromosome 35 was seen in a canine MCT (73). (28).…”

Breed-Predispositions to Cancer in Pedigree Dogs

“…Alterations in the p53 tumour suppressor pathway have been identified in some canine MCTs but TP53 sequencing in a small number of cases did not reveal any mutations [137]. …”

Sequence analysis ofRASandRAFmutation hot spots in canine carcinoma

“…The high prevalence of RAS mutations in a wide variety of human cancers, along with the high homology between species, has led to a number of studies investigating RAS mutations in canine cancer as a spontaneously occurring cancer model. These studies, however, revealed that RAS mutations are infrequent in canine cancers except for several cancer types (summarized in Table ), posing a question whether the MAPK pathway plays a similar role in the carcinogenesis of canine cancer as in humans.…”