Frederick Singer, M.D.
Goals and Areas of Research
Sestamibi scanning (imaging based on the technetium-99m radioisotope) is used to determine the extent of surgery for primary hyperparathyroidism, but its efficacy depends on gland size and location. Investigators in the Endocrine/Bone Disease laboratory and the Molecular Oncology Department have shown that gene expression also plays a role. Hypermethylation (epigenetic mutation) of the MDR1 gene prevents the MDR1 transporter protein from clearing radioisotope, thereby allowing visualization of the abnormal gland(s) in patients with parathyroid adenomas. In a related study, JWCI investigators are analyzing patterns of protein expression in parathyroid tissue and blood from patients with sporadic or familial primary hyperparathyroidism; the goal is determine whether protein profile can distinguish patients with single parathyroid tumors from those with four-gland disease.
Prostate cancer is the most common malignancy in males. Although the serum level of PSA (prostate-specific antigen) is used for prognostic and diagnostic assessment, it is not very accurate. JWCI’s Endocrine/Bone Disease laboratory is therefore collaborating with the Molecular Oncology Department to study molecular aberrations that characterize prostate cancer. The goal is to develop a highly sensitive and specific multimarker assay to detect two types of DNA mutations (epigenetic and genetic) in the serum.
Paget's disease is the second most common bone disease, affecting one to two million Americans. This metabolic disorder reflects an imbalance between between bone formation and bone resorption; cells that absorb bone (osteoclasts) become more active than the cells that make bone (osteoblasts). The etiology of Paget’s is poortly understood. Mutations in sequestosome 1 have been implicated but it is not clear that genetic mutations alone can produce the pagetic phenotype. Recent research suggests an interaction between sequestosome 1 and measles virus. The Endocrine/Bone Disease Laboratory is collaborating with the University of Pittsburgh and the University of Texas at San Antonio to investigate genetic and viral influences in the development of Paget’s disease.
Endocrine and Bone Disease Disease Program at Saint John's Health Center ›