Breast cancer proteomics by laser capture microdissection, sample pooling, 54 cm immobilised pH gradient isoelectric focussing, and differential iodine radioisotope detection

The presence of progesterone receptor (PR) in estrogen receptor (ER)-positive breast cancer is associated with good prognosis and indicates that tumors are likely to respond to tamoxifen. However, ER+/PR- respond less well. In order to reveal the potential molecular mechanism of this phenomenon we sought to identify differential protein abundances between invasive ductal carcinoma cells from cryopreserved ER+/PR+ and ER+/PR- mammary tumor specimens. Because current proteomics methods are hampered in the examination of most primary human tumor samples by extreme tissue heterogeneity, laser capture microdissection…