Loss of Heterozygosity in Multiple Endocrine Neoplasia- 2A Adam Greenbaum Mentor: Paul Goodfellow, Ph.D. Department of Surgery and Department of Genetics, Washington University School of Medicine, St. Louis, MO. Cancers often have chromosomal aberrations and other genomic mutations. One such mutation results in loss of heterozygosity (LOH), in which allele is totally removed from one chromosome, resulting in complete expression of the other allele. Often, tumor cells will lose tumor suppressor genes via LOH. Multiple Endocrine Neoplasia 2A (MEN2A) is an autosomal dominant cancer syndrome caused by a mutation in the RET proto-oncogene. All patients with MEN2A develop medullary thyroid carcinoma (MTC), and about 40% develop adrenal cancers known as pheochromocytoma (Pheo). Previous studies using the RET orthologue in Drosophila have shown that five other genes enhance the effect of the RET gene; among these genes are SIN3A, KIAA0308, and TNIK. In order to determine which additional acquired genetic changes are associated with MEN2A tumor development, MTC and Pheo tumors were compared to normal cells from the same patient to screen for LOH. The three markers were determined to be highly polymorphic and informative, but SIN3A and KIAA showed few or no signs of LOH in both MTC and Pheo tumors. TNIK showed no LOH in MTC; however, TNIK showed a high rate of LOH in Pheo tumors. This suggests that TNIK may be a tumor suppressor gene in MEN2A human. Scholar Index Next   Natural Sciences Learning Center Washington University - Biology All contents copyright © 2001 Email comments to nslc webmanager