Calcium efflux pump, PMCA2, in human breast tissue with lactational change and as a therapeutic target in breast cancer

Publication date: January 2015 Source:New Horizons in Translational Medicine, Volume 2, Issue 2 Author(s): Amelia A. Peters , Wei C. Lee , Eloise Dray , Chanel E. Smart , Lynne Reid , Leonard da Silva , Sunil R. Lakhani , Sarah J. Roberts-Thomson , Gregory R. Monteith Calcium pumps and channels modulate cell proliferation and apoptosis by regulating intracellular calcium (Ca2+). The plasma membrane Ca2+ ATPase isoform, PMCA2, is a calcium efflux mechanism that extrudes Ca2+ from the cytosol into the extracellular space. PMCA2 has a restricted expression, including expression in cochlear hair cells and cerebellar Purkinje cells. PMCA2 expression is increased in mouse mammary glands during lactation where it plays a major role in the excretion of Ca2+ into milk; however, PMCA2 expression has not been assessed in human breast tissue exhibiting lactational changes. Our previous studies have shown that PMCA2 mRNA levels are elevated in some breast cancer cell lines and that pan-PMCA antisense attenuates the proliferation of MCF-7 breast cancer cells. However, the consequences of silencing PMCA2 in breast cancer cells are still not well understood. Our study assessed PMCA2 expression in breast tissue exhibiting lactational change and in human malignant breast tissue samples. The role of PMCA2 in the proliferation of breast cancer cells was also evaluated. Immunohistochemistry using a rabbit anti-PMCA2 antibody showed membranous PMCA2 expression in the luminal epitheliu...
Source: New Horizons in Translational Medicine - Category: Research Source Type: research