Activation of mammalian target of rapamycin (mTOR) in triple negative feline mammary carcinomas
1 University of Turin, Department of Veterinary Sciences, via L. da Vinci 44, 10095 Grugliasco, Italy
2 University of Córdoba, Department of Comparative Pathology, Faculty of Veterinary Medicine, Carretera Madrid-Cádiz km 369, 14014 Córdoba, Spain
3 Veterinary Surgery, Graduate School of Agricultural and Life Sciences, the University of Tokyo,1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan
4 University of Torino Medical School, Department of Oncological Sciences at the Institute for Cancer Research and Treatment SP 142, Km. 3.95, 10060 Candiolo, Turin, Italy
BMC Veterinary Research 2013, 9:80 doi:10.1186/1746-6148-9-80Published: 15 April 2013
Triple negative breast cancer (TNBC) in humans is defined by the absence of oestrogen receptor (ER), progesterone receptor (PR) and HER2 overexpression. Mammalian target of rapamycin (mTOR) is overexpressed in TNBC and it represents a potential target for the treatment of this aggressive tumour. Feline mammary carcinoma (FMC) is considered to be a model for hormone-independent human breast cancer. This study investigated mTOR and p-mTOR expression in FMC in relation to triple negative (TN) phenotype.
The expression of mTOR, p-mTOR, ERα, PR and HER2 was evaluated in 58 FMCs by immunohistochemistry and in six FMC cell lines by Western blot analysis. 53.5% of FMC analyzed were ER, PR, HER2 negative (TN-FMC) while 56.9% and 55.2% of cases expressed mTOR and p-mTOR respectively. In this study we found that m-TOR and p-mTOR were more frequently detected in TN-FMC and in HER2 negative samples.
In this study, we demonstrate that there is also a FMC subset defined as TN FMC, which is characterised by a statistically significant association with m-TOR and p-mTOR expression as demonstrated in human breast cancer.