Gene Expression of Hormone Receptors and Growth Factors in Intact and Neutralized Female Dogs, Both Healthy and with...

Mast cell tumors are the most common skin neoplasm in dogs and may be influenced by reproductive status. A gonadectomy modifies gonadotropin levels and may affect the expression of hormonal receptors and proliferative factors; however, the evidence for this remains limited. The objective of this study was to evaluate the expression of VEGF, IGF-1, PCNA, Ki-67, c-KIT, LHR, FSHR, and ERα in intact and neutralized female dogs with and without MCTs. Gene expression in the skin samples was quantified by a real-time PCR, and four groups were included: intact controls (n = 10), neutralized controls (n = 10), intact MCT (n = 9), and neutralized MCT (n = 10). Tumor presence was associated with increased expression of LH and FSH receptors and c-KIT, while angiogenic and proliferative factors (PCNA, Ki-67, IGF-1, VEGF, and ERα) showed lower expression. In dogs with MCTs, a gonadectomy was associated with higher c-KIT and VEGF expression but lower LHR mRNA levels. PCNA expression was lower in the neutralized MCT dogs compared to the neutralized controls, whereas no differences were observed in the intact dogs. Additionally, ERα expression was higher in the neutralized control dogs than in the intact controls, with no differences detected in the MCT dogs. These findings suggest that reproductive status is associated with differential regulation of molecular pathways involved in canine MCT biology.