Heat shock proteins have essential roles in a number of pathophysiologic conditions including carcinogenesis and represent a group of novel molecular markers in cancer management. The aim of this study was to investigate heat shock protein expression in correlation with other neoplasm traits such as: histological type, differentiation grade, proliferative activity, estrogenic receptor expression, and cyclooxygenase-2 and p53 proteins. Material for the investigation comprised 133 tumors of the mammary gland collected from bitches. In total 14 adenomas, 66 complex carcinomas, 47 simple carcinomas and 6 solid carcinomas were collected. Evaluations were conducted with histopathological and immunohistochemical methods using suitable antibodies. Expression of heat shock protein 70 was observed in all types of evaluated neoplasms. A higher average number of cells undergoing expression of heat shock protein 70, which was statistically insignificant, was established in complex and simple cancers and in cancers with the 1st and the 2nd degree of histological malignancy. Expression of heat shock protein 90 was observed in all studied neoplasms; it was very insignificant in adenomas, compared to cancers, and the highest expression was established in the solid cancers, as well as in cancers with the 2nd degree of histological malignancy. This high expression of heat shock protein 90 was correlated with proliferative activity. The results suggest that heat shock protein 90 is involved in canine mammary gland carcinogenesis. The results also suggest that heat shock protein 90 may be a prognostic factor, but this requires detailed clinical confirmation.
The aim of the study was to investigate E-cadherin expression in correlation with other neoplasm traits such as: histological type, the differentiation grade and proliferative activity. Material for the investigation comprised mammary gland tumours, collected from dogs, the patients of veterinary clinics, during surgical procedures and archival samples. All together 21 adenomas, 32 complex carcinomas, 35 simple carcinomas and 13 solid carcinomas were qualified for further investigation. E-cadherin expression was higher in adenomas as compared with carcinomas but lower in solid carcinomas as compared with simple and complex carcinomas. More over, the expression of E-cadherin decreased with the increase in the neoplasm malignancy and proliferative activity (value of the mitotic index and number of cells showing Ki67). The study has shown that the expression of E-cadherin can be used as a prognostic factor.