Comprehensive analysis of the expression of the metastasis-associated gene 1 in human neoplastic tissue

Context.-The metastasis-associated gene 1 (MTA1) is overexpressed in several human cancers. Recent reports suggest that MTA1 may play a role in cancer progression either through transcription repression and/or hormone receptor interactions. Objective.-To analyze MTA1 expression levels in a wide variety of human tumors. Design.-We used Oncomine, an Internet-based compendium of expression array data, to query more than 90 expression array studies, and we evaluated tissue microarrays composed of more than 3200 samples representing 138 different localized neoplasms. Results.-Both analyses show that MTA1 is ubiquitously expressed in benign and malignant tumors. The highest levels of MTA1 expression were observed in diffuse B-cell lymphoma (mean staining intensity, 3.9/4), basal cell carcinomas (3.7/4), and consistently in tumors of neuroendocrine descent such as paraganglioma (3.7/4) and carcinoid tumor (3.1/4). Conclusions.-This study characterizes MTA1 expression for the first time across a broad spectrum of primary tumors, demonstrating expression in both benign and malignant neoplasms in addition to showing an association with neuroendocrine differentiation. We also found evidence that MTA1 expression is associated with tissue invasion but may not be sufficient for the progression to metastatic stages.