Copy number variation in ACHE/EPHB4 (7q22) and in BCHE/MME (3q26) genes in sporadic breast cancer

Gene amplifications and deletions are common changes in human cancer cells. Previous studies indicate that the regions, where the ACHE (7q22) and BCHE (3q26.1-q26.2) genes are localized, are suffering such structural modifications in breast cancer. Therefore, the products of these genes, acetylcholinesterase and butyrylcholinesterase, respectively, are related to the process of cell differentiation and proliferation, as well as apoptosis. This study also included two other genes involved in tumorigenesis, the EPHB4 (7q22.1) and MME (3q21-27). The aim of this study was to verify amplification and/or deletion in the ACHE, BCHE, EPHB4 and MME genes in 32 samples of sporadic breast cancer. The gene alterations were detected using real-time PCR and determined by relative quantification with the standard curve method. All samples presented genetic alterations, showing a higher tendency for amplification of the ACHE (62.5% vs. 37.5%; p > 0.1) and EPHB4 (53.13% vs. 46.88%; p > 0.5) genes, and for deletions of the BCHE and MME genes (56.25% vs. 43.75% for both; p > 0.5). A positive correlation was found between alterations in ACHE-EPHB4 and BCHE-MME pairs (rs = 0.5948; p = 0.0004; rs = 0.3581; p = 0.0478, respectively) indicating that these changes comprise a wide region. In conclusion, the results suggest that these genomic regions may contain important genes for this pathology, such as the oncogenes MET (7q31) and PIK3CA (3q26), and thus being interesting targets for future studies in breast cancer research.

► A positive correlation was found between alterations in BCHE-MME pair. ► A positive correlation was found between alterations in ACHE-EPHB4 pair. ► We obtained a tendency to deletion of MME and BCHE genes.