Member, Cancer Immunology, Inflammation and Tolerance Program
GRU Cancer Center
Assistant Professor of Biochemistry and Molecular Biology
1120 15th Street, CN 1162
Phone: (706) 721-6238
Dr. Singh earned his Ph.D. (1998) from National Institute of Immunology, New Delhi, India. Dr. Singh is a Assistant Professor in the Department of Biochemistry and Molecular Biology in the Medical College of Georgia at GRU. His research focuses on intestinal inflammation and its role in the development of intestinal cancers and obesity, and leukemias.
Dr. Singh is studying how dietary fibers and good bacteria in the gut suppress intestinal inflammation and cancers such as colorectal cancers. Consumption of dietary fibers is associated with decreased inflammation and carcinogenesis in the intestine and suppression of obesity. How do dietary fibers exert their beneficial effect on health? In the intestine, dietary fibers are fermented by intestinal bacteria into short chain fatty acids (SCFAs), mainly acetate, propionate and butyrate. Among the SCFAs, butyrate has received more attention for its anti-inflammatory and anti-tumorigenic properties. Butyrate enemas are one of the treatments for colitis, a risk factor for development of colorectal cancers. The intestine expresses butyrate receptors GPR41, GPR43 and GPR109A. Dr. Singh is currently examining the role of these butyrate receptors in development of intestinal inflammation and colorectal cancers. In addition, he is also interested in studying the role of these receptors and other butyrate targets in suppression of obesity.
Nucleosides are used as chemotherapeutic drugs to treat several forms of cancer including leukemias. For nucleosides to induce regression of cells, they need to be transported inside the tumor cells. Concentrative nucleoside transporters (CNTs) and equilibrative nucleoside transporters (ENTs) play an essential role in the transport of nucleosides across the cell membrane. Dr. Singh’s laboratory also studies the role of CNTs and ENTs in development and treatment of leukemia and other cancers.
Singh N, Pacholczyk R, Iwashima M, Ignatowicz L. Generation of T Cell Hybridomas from Naturally Occurring FoxP3(+) Regulatory T Cells. Methods Mol Biol. 2011;707:39-44.
Zimmerman M, Yang D, Hu X, Liu F, Singh N, Browning D, Ganapathy V, Chandler P, Choubey D, Abrams SI, Liu K. IFN-γ upregulates survivin and Ifi202 expression to induce survival and proliferation of tumor-specific T cells. PLoS One. 2010 Nov 22;5(11)
Sukumari-Ramesh S, Laird MD, Singh N, Vender JR, Alleyne CH Jr, Dhandapani KM. Astrocyte-derived glutathione attenuates hemin-induced apoptosis in cerebral microvascular cells. Glia. 2010 Aug 24. [Epub ahead of print]
Singh N, Thangaraju M, Prasad PD, Martin PM, Lambert NA, Boettger T, Offermanns S, Ganapathy V. Blockade of dendritic cell development by bacterial fermentation products butyrate and propionate through a transporter (Slc5a8)-dependent inhibition of histone deacetylases. J Biol Chem. 2010 Sep 3;285(36):27601-8.
Singh N, Huang L, Qin H. Defective T-cell receptor-induced apoptosis of T cells and rejection of transplanted immunogenic tumors in p53(-/-) mice. Eur J Immunol. 2010 Feb;40(2):559-68.
Singh N, Yamamoto M, Takami M, Seki Y, Takezaki M, Mellor AL, Iwashima M.CD4(+)CD25(+) regulatory T cells resist a novel form of CD28- and Fas-dependent p53-induced T cell apoptosis. J Immunol. 2010 Jan 1;184(1):94-104.
Sangeetha SR, Singh N, Vender JR, Dhandapani KM. Suberoylanilide hydroxamic acid (SAHA) induces growth arrest and apoptosis in pituitary adenoma cells. Endocrine. 2009 Jun;35(3):389-96.
Publications are updated quarterly. For a complete listing, see Dr. Singh’s work on PubMed.