Anti-BCAR3 (Breast Cancer Anti-estrogen Resistance Protein 3, Novel SH2-containing Protein 2, SH2 Do

In breast cancer, the antiestrogen tamoxifen has been prescribed for both primary treatment and the treatment of advanced metastatic disease. Although the drug induces remission in most patients with estrogen receptor-positive disease, all patients eventually develop resistance. van Agthoven et al. (1998) applied an insertional mutagenesis strategy to a breast cancer cell line. Infected cells were subjected to tamoxifen selection, and the resistant clones were screened for a common integration site linked with antiestrogen resistance. By screening a human testis cDNA library with the integration site-specific probe, they obtained a cDNA encoding BCAR3 (breast cancer antiestrogen resistance 3). The deduced 825aa BCAR3 protein contains a putative Src homology 2 (SH2) domain and sequences homologous to yeast CDC48. Northern blot analysis detected abundant expression of a 3.4kb BCAR3 transcript in heart, placenta, skeletal muscle, spleen, prostate, testis, ovary, small intestine, colon, fetal kidney, and several cancer cell lines, but not in nonmalignant breast tissue, a 6kb BCAR3 transcript was also detected in skeletal muscle and heart. Applications: Suitable for use in ELISA and Western Blot. Other applications not tested. Recommended Dilution: ELISA: 1:32,000, Western Blot: 0.5-2ug/ml, Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.