HUMAN ACHAETE-SCUTE HOMOLOG-1 IS HIGHLY EXPRESSED IN A SUBSET OF NEUROENDOCRINE TUMORS

Human achaete-scute homolog-1 (hASH1) is critical for establishing the neuroendocrine (NE) phenotype of small cell lung cancer. To define it s role in other neoplasms, we analyzed 33 tumors for hASH1 by Northern blotting. Significant levels of hASH1 mRNA were detected in 4 pheochr omocytomas, 2 medullary thyroid cancers, and 1 thymic carcinoid. hASH1 transcripts were undetectable in 8 parathyroid lesions, 6 gastrinomas , 4 insulinomas, and 7 thyroid neoplasms, as well as in normal thyroid , adrenal, or pancreas tissue. Therefore, hASH1 mRNA is highly abundan t in a subset of human tumors and may play a role in dictating their N E phenotype.