Sajitha I.S.RAIMON MATHEW2022-11-012022-11-012019-09-30https://krishikosh.egranth.ac.in/handle/1/5810189497Thesis submitted in partial fulfillment of the requirement for the degree of Master of Veterinary science in Veterinary PathologyThe present work was undertaken to study the expression of two proteins, critical in the cell signaling pathway namely, mechanistic target of Rapamycin (mTOR) and Dishevelled, EGL10 and Pleckstrin domain containing mTOR interacting protein (DEPTOR) in canine mammary and superficial tumours. Excision biopsy samples of mammary and skin tumour suspected growths from dogs presented to University Veterinary hospitals, Mannuthy and Kokkalai were collected for the study during the period from January 2018 to March 2019. Out of the 129 tumour suspected cases, 22 were mammary tumour growths and 17 were superficial tumour growths. Age wise analysis revealed that the mean age of the dogs affected with mammary tumours and superficial tumours was 7.85±0.41 years and 6.55±0.59 years respectively. The highest incidence of both the tumours was seen in the age group of seven to nine years. All the mammary tumours were recorded in female dogs but in case of superficial tumours male dogs (58.82 per cent) were more affected. Data on breed-wise occurrence showed the highest occurence of both the type of tumours in Labradors. Among the mammary tumours, 90 per cent were malignant and 10 per cent were benign, where as in case of superficial tumours majority (76.47 per cent) were benign in nature. Grossly CMTs varied in shape, colour and consistency with a mean size of 6.70±0.60 cm. The superficial tumours were predominantly round to oval in shape with grayish white colour having a mean size of 4.65±0.37cm. On grading of malignant CMTs, majority of the simple carcinomas, which are the most malignant type, had higher grade of II or III. Immunohistochemistry for mTOR and DEPTOR has revealed that both the proteins were significantly expressed (p0.05) with expression of these proteins. The mean expression of mTOR in mammary tumours and superficial tumours was significantly higher (p<0.01) than that of DEPTOR. Further, it was also found that there was significant positive correlation (p<0.01) between the expression of mTOR and DEPTOR in both these type of tumours. Thus, the present study identified that the two key proteins in cell signaling pathway, the mTOR and DEPTOR, were significantly expressed in canine mammary and superficial tumours. Further it was shown that their expression was positively correlated. Hence the oncogene role of DEPTOR in CMTs and CSTs was established through the study.EnglishThesis