Synaptic vesicle protein isoforms (SV2A, SV2B, SV2C): Expression in breast cancer and their association with risk factors and metastasis in Mexican women

Breast Cancer (BCa) is a global public health problem in that is one of the main causes of deaths due to cancer in women. Synaptic Vesicle Protein (SV2) is a neuronal protein with three isoforms. Recent research on tumor cells has identified Synaptic Vesicle SV2 receptor isoform A (SV2A) in different types of cancer, such as colon, prostate, and the BCa cell line. The aim of this research was to identify the protein expression of isoforms A (SVA), B (SV2B), and C (SV2C) of the SV2 receptor in the tissues of patients with a diagnosis of BCa, and its relation with clinicopathological factors. Tissues were obtained from patients treated with radical mastectomy, while control tissue was obtained by cosmetic mastoplasty. The technique used to determine the protein expression of SV2 isoforms in these tissues was immunohistochemistry. We found significant SV2A, SV2B, and SV2C overexpression in BCa tissues in comparison with normal breast tissue. A significant association among protein expression with smoking, biomass exposure, and comorbidities was found. Additionally, we observed differences in the expression of these proteins with regard to metastasis. SV2A, SV2B, and SV2C proteins are overexpressed in BCa tissues, and their expression is related with different clinicopathological features in patients with BCa.