Spontaneous canine transmissible venereal tumor: association between different phenotypes and the insertion LINE-1/c-myc

Objective: this study aimed to evaluate the LINE-1 transposon inserted in c-myc gene as a specific genetic alteration in cells of spontaneous canine Transmissible Venereal Tumor (TVT) with either lymphocytoid or plasmacytoid phenotypes. Methods: tumoral biopsies from 35 dogs were collected by puncture or exfoliation. Polymerase Chain Reaction (PCR) was carried out with primers myc.s and LINE. A, specific to the LINE-1 segment to detect the presence of LINE-1/c-myc molecular marker. Results: sequence alignment of DNA samples from lymphocytoid and plasmacytoid TVT cells did not show polymorphisms, and the comparison with sequences from the GenBank identified them as a LINE-1/c-myc rearrangement. Conclusions: considering the aggressive nature of the plasmacytoid phenotype, there is no apparent relation between LINE-1/c-myc and the malignancy of TVT. Further studies are needed to establish molecular differences associated with the aggressiveness of the various phenotypes of canine TVT.