Skip to Main Content

Chih-Chi Andrew Hu, Ph.D.

Chih-Chi Andrew Hu, Ph.D.

Laboratory

The Hu Laboratory

Contact

215-495-6976
chu@wistar.org

Associate Professor, Immunology, Microenvironment & Metastasis Program

About the Scientist

Hu's research interests include the analysis of the mechanisms of B cell development and B cell cancer formation. He investigates endoplasmic reticulum-associated stress signaling molecules, which play important roles in the quality control of secretory and integral membrane proteins. Hu is especially interested in knowing how B cell cancers employ these signaling molecules to work in favor of their survival, spreading and chemoresistance in response to therapies. These signaling molecules may also play a role in tumor development in other organs, and are being evaluated in melanoma and other tumor types. Hu and his lab take biochemical, cell biological, and immunological approaches to study these questions in mouse tumor models and human cancer cells.

Hu received his M.S. in cancer biology at National Sun Yat-Sen University in Taiwan and his M.S. and Ph.D. at New York University School of Medicine. Prior to joining Wistar, he was an Assistant Member at H. Lee Moffitt Cancer Center and Research Institute in Tampa.

View Publications

The Hu Laboratory

The Hu laboratory studies endoplasmic reticulum (ER), which has critical functions in lipid synthesis, calcium storage and drug metabolism. The ER also contains complex machineries to fold, assemble, transport or – as the need arises - destruct many vital integral membrane growth receptors and secretory proteins. The Hu lab strives to better understand he complexity of the ER functions.

Staff

Postdoctoral Fellows

Andong Shao, Ph.D.
Anthony Tang, M.D., Ph.D.

Research Assistants

Shiun Chang
Judy Chen

Research

The Hu lab studied the ER functions in B cells because differentiated B cells produce a dramatically expanded ER for the production and secretion of antibodies to fight infections. Misfolded antibodies are unavoidable byproducts in the ER upon massive production of antibodies, and they were believed to activate the XBP-1 transcription factor, which was arguably one of the most important factors in correcting protein misfolding problems and expanding the size of the ER. Thus, Hu's lab chose XBP-1 to peek into the biology of the ER. Our initial pursuit of the function of XBP-1 led to surprising conclusions that XBP-1 is not activated by misfolded antibodies and XBP-1 plays minimal role in correcting misfolded proteins in B cells. These conclusions were reached by disabling B cells of their capability in making antibodies and by deleting the XBP-1 gene from the B cells. Further investigation by the lab suggested that XBP-1 is activated by differentiation cues. This work revealed new roles for XBP-1 in regulating signal transduction through the B cell receptor; in regulating the expression of important transcription factors in B cells; in maintaining proper lipid synthesis and protein glycosylation in B cells; and in colonization of stimulated B cells into the bone marrow for sustention of antibody production.

Inspired by XBP-1’s roles in maintaining a homeostatic ER, the lab began to examine the role of XBP-1 in B-cell leukemia whose progression does not require dramatic ER expansion like that in multiple myeloma. The lab chose to use the TCL1 mouse model to study B-cell leukemia because ~90 percent of human chronic lymphocytic leukemia (CLL) patients express the TCL1 protein, and the overexpression of TCL1 in B cells leads to the development of CLL in mice. We showed that TCL1 oncoprotein associates with XBP-1 and turns on vital ER proteins to support leukemic growth. When the function of XBP-1 is genetically deleted in TCL1 mice, significantly slower leukemic progression is observed. The lab further developed inhibitors to target the expression of XBP-1 and established that blocking the expression of XBP-1 by specific small-molecule chemical inhibitors can stall malignant progression of leukemia in mice and induce apoptosis in primary human leukemic cells. Currently, the Hu lab continues to analyze the functions of ER proteins in malignant progression of leukemia using novel mouse models, in which we selectively deleted genes that encode critical ER-resident proteins that support the growth and survival of leukemia. The Hu lab is also generating new mouse models to expand the breadth of our investigation. The ultimate goal of this work is to contribute to the design of effective therapeutic approaches that target dysregulated ER functions for patients with leukemia and other malignancies.

Specific laboratory projects:

  • Investigate IRE-1-interacting proteins to further understand how targeting the IRE-1/XBP-1 pathway can lead to stalled progression of CLL
  • Investigate the roles of protein antigen and Toll-like receptor ligands in activating the ER stress response to promote leukemic progression
  • Investigate the roles of protein misfolding in B-cell leukemia