Carnitine palmitoyltransferase 1 A expression profile in canine mammary tumors

Genetic alterations and/or epigenetic modifications occur frequently in the majority of cancer cells. In addition to playing a crucial role as promoters of tumorigenesis, these processes can also generate metabolic pathways that are different from those in normal cells. Besides the Warburg effect, an alteration in lipid metabolism is also found in cancer cells. Thus, elucidation of the regulators involved in this metabolic reprogramming might provide tools for diagnosis, prognosis, and ultimately treatment of canine mammary tumours (CMTs) in particular. One such regulator is carnitine palmitoyltransferase 1A (CPT1A), which is involved in transportation of long-chain fatty acids into the mitochondrial matrix for beta-oxidation, thereby providing an alternative pathway for the generation of energy for tumour growth and development. In this study, the canine cell lines MDCK, CMT-U309, CMT-U27, and P114 were used as in vitro models for western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. Furthermore, western blot and immunohistochemistry were carried out to evaluate CPT1A protein expression in the CMT specimens. The CPT1A protein and mRNA expression levels were increased in the CMT cell lines relative to their levels in normal epithelial cells. Moreover, increased CPT1A expression levels were found in the CMT tissues, being inversely correlated with the tumour differentiation grade. However, additional studies are required to further specify the role of CPT1A in CMTs.