Associate Professor of Cell and Molecular Biology, Feinberg School of Medicine
The main focus of the Huang lab's research is to understand the nature and function of a unique nuclear structure, the perinucleolar compartment (PNC) and its relationship with the malignant phenotype. The PNC is an electron dense structure forming a reticulated mesh on the surface of the nucleolus. It is predominantly observed in transformed cells, and is rarely found in normal cells. Several small RNAs transcribed by RNA polymerase III and two hnRNP proteins have thus far been localized in this structure. The PNC intensely incorporates Br-U (a nucleotide analogue) in permeabilized cells after a short pulse labeling and a PNC-associated RNA binding protein, PTB, moves in and out of PNC rapidly. These observations suggest that the PNC is a dynamic and functional subnuclear compartment, which may be involved in transcription and/or RNA post-transcriptional processing in cancer cells. More recently, preliminary studies suggest that suppressing the function of an anti-oncogene (p53) significantly increases PNC prevalence (the percentage of cells that contain at least one PNC). These studies used cells stably transfected with a ts p53 mutant in a p53 -/- background. In addition, the integrity of the PNC is dependent upon RNA polymerase I activity, which is in part regulated by p53. These findings suggest that the high PNC prevalence in transformed cells may reflect the elevated level of rRNA synthesis in cancer cells.
Office: Ward 11-240
Email: s-huang2 [at] northwestern [dot] edu