Anti-Mammaglobin A/MGB1: Mouse Mammaglobin A/MGB1 Antibody

The mammaglobin A gene (SCGB2A2) encodes a 93-amino acid protein with a predicted molecular mass of 10.5 kDa. In breast tissue it exists in two main forms with approximate molecular masses of 18 and 25 kDa, due to posttranslational modifications. Mammaglobin A is considered to be a highly specific breast tissue marker; initially it was found to be overexpressed in breast cancer, and its expression was restricted to normal and malignant breast tissue. Mammaglobin A was detected immunologically or by RT-PCR in 70 to 100% of the primary and metastatic breast cancer samples examined and in normal breast, but no other normal tissues. Moreover, over 10-fold higher levels of expression were detected by Northern analysis of tumor RNA than by that of patient-matched normal breast RNA. Numerous studies have demonstrated that mammaglobin A is the most specific marker for breast cancer currently available at both the protein and the RNA level.² No gene amplification or gene rearrangement was detected in tumors overexpressing mammaglobin A, suggesting changes in transcriptional regulation as the cause of overexpression.³ In contrast to other members of the secretoglobin family, its expression does not appear to be influenced by steroid hormones. Due to its tissue specificity, mammaglobin A has drawn much attention. Various studies have evaluated its role in detection of minimal residual disease in breast cancer patients, while others investigated its role as a diagnostic and prognostic marker, and its potential use as a therapeutic target. However, some studies have shown that it is also expressed in tissues other than the breast.⁴ In breast cancer mammaglobin A is overexpressed in a high proportion of primary tumors, and it is associated with estrogen receptor positive tumors, a less aggressive tumor phenotype, and relapse-free survival.