Nianli Sang, PhD
Co-Director of the Cell Imaging Center; Associate Professor
Office: PISB 417
Lab: PISB 401 H2
Lab Phone: 215.895.1436
Molecular, Cellular and Biochemical Bases of Major Human Diseases
- Bachelor of Medicine, Fudan University, Shanghai Medical College, China, 1982-1988
- Master of Surgery (Residency), Zhongshan Hospital, Fudan University, Shanghai Medical College, China, 1988-1992
- PhD, Genetics, Thomas Jefferson University, Kimmel Cancer Center, 1992-1997
- Post-doctoral training, University of Pennsylvania School of Medicine, Institute of Human Gene Therapy, 1997-1999
- Post-doctoral training, Thomas Jefferson University Hospital, Cardeza Foundation for Hematological Research, 2000-2003
Research in our lab focuses the regulation of cell metabolism and its relevance in major human diseases such as cancer, cardiovascular disorders and diabetes. Cell metabolism provides the molecular and biochemical bases for normal cell function. Altered metabolic processes are associated with a variety of human diseases. The basic metabolic pathways involved in the utilization of carbon source, nitrogen source and molecular oxygen have been clear for many years and their importance has become common sense. However, how cells monitor the supply levels of these critical nutrients, and relay the signals to direct a metabolic adaptation remains unclear. Our general work model is that the supply levels of these critical nutrients initiate signaling events that lead to transcription reprogramming. The transcription reprogramming in turn, results in metabolic reprogramming and other adaptive responses. Finally, the cellular level adaptive response forms the foundation of tissue level and organismal level adaptation. Specifically,
The oxygen sensing and signaling pathways have been well characterized. Molecular oxygen is an absolute requirement for the metabolism of most organisms on the earth including all animals. Hypoxia-inducible factors 1 and 2 (HIF-1, HIF-2, and collectively, HIF) are heterodimeric nuclear transcription factors regulated by oxygen and various signaling pathways. It has been generally that they are the master regulators of angiogenesis, coupled glucose-oxygen metabolism and response to biological stresses, which are triggered by a variety of biological and pathological conditions ranging from early development, tumorigenesis, ischemic disorders, diabetes, aging and infectious diseases. Following this direction, our current research focuses on four intrinsically related issues: 1) to understand the cellular, molecular and biochemical bases underlying the regulation of HIF function in normal and tumor cells; 2) to understand the biochemical and pharmacological mechanisms underlying the repressive effects of chemotherapeutics on HIF activity; 3) to investigate the roles of HIF in the physiology and pathophysiology of endothelial cells and neurons, emphasizing on molecular, biochemical and cellular bases of human diseases; and 4) To explore potential application of the HIF system in novel diagnosis and therapies for human diseases.
We also have started to dissect the signaling pathways and transcriptional reprogramming triggered by insufficient supply of carbon or nitrogen sources. Towards that direction, we are expecting to understand: 1). What are the cellular level sensing systems for carbon and nitrogen sources? 2). How is the utilization of carbon and nitrogen sources coordinately regulated? 3). How do oncogenic signaling pathways stimulate and coordinate the utilization of carbon and nitrogen sources?
Current Research Funding:
Total Award: $1,563,600
“Repressing HIF-1: targets and mechanisms”
(*As corresponding author)
Sang, N., Fang, J., Srinivas, V., Leshchinsky I., and *Caro, J. (2002) Carboxyl terminal transactivation activity of HIF-1? is governed by a VHL-independent, hydroxylation-regulated, association with p300/CBP. Mol. Cell. Biol., 22:2984-2992.
*Sang, N., Stiehl, D.P. Bohensky, J., Leshchinsky, I., Srinivas, V., and *Caro, J. (2003) MAPK Signaling Up-regulates the activity of hypoxia-inducible factors by its effects on p300. J. Biol. Chem., 278: 14013-14019.
Kong, X., Lin, Z., Liang, D., Fath, D., *Sang, N., and *Caro, J. (2006) Histone-deacetylase inhibitors induce VHL and ubiquitin-independent proteasomal degradation of HIF-1?. Mol. Cell Biol., 26:2019-2028.
Fath, D.M., Kong, X., Liang, D., Lin, Z., Chou, A., Jiang, Y., Fang, J., Caro, J. and *Sang, N. (2006) Histone deacetylase inhibitors repress the transactivation potential of hypoxia inducible factors independently of direct acetylation of HIF-??? J. Biol. Chem., 281:13612-13619.
Stiehl, D.P, Fath, D.M., Liang, D.M., Jiang, Y.B., and *Sang, N. (2007) Histone deacetylase inhibitors synergize p300 autoacetylation that regulates its transactivation activity and complex formation. Cancer Res., 67(5): 2276-2286.
Meng, M., Chen, S., Lao, T., Liang, D., and *Sang, N. (2010) Nitrogen Anabolism underlies the glutaminolysis in proliferating cells. Cell Cycle, 9(19): 3921 - 3932.