Most lymphoid malignancies arise by transformation of germinal center (GC) experienced B cells. In two prior funding periods we showed that the TCL1 proto-oncogene was abnormally expressed in samples from three major GC B cell lymphoma categories, including follicular (FL), Burkitt (BL), and diffuse large B cell (DLBCL) lymphomas. Two sets of Specific Aims addressed a causative role for aberrant TCL1 expression in the transformation of GC B cells and the mechanism(s) for regulating and dysregulating TCL1 expression in human B cell malignancies. Funding supported our group for 66 peer-reviewed publications. Now, we propose to logically expand the scope of prior successful work beyond TCL1 into an exciting new direction. During an immune response, B cells undergo rapid proliferation and remodeling of immunoglobulin (IG) genes within GCs to generate memory B and plasma cells. Unfortunately, DNA damage associated with this "GC reaction" also promotes most B cell malignancies. We recently discovered that ATM, activated by AID- dependent DNA double-stranded breaks (DSBs) during IG class switch recombination (CSR) in GC B cells, signals through LKB1 to inactivate CRTC2, a known transcriptional co-activator of CREB. Using genome-wide location analysis, we determined that CRTC2 inactivation unexpectedly repressed a genetic program that controls GC B cell proliferation, self-renewal, and differentiation into antibody (Ab)-secreting plasma cells while opposing lymphomagenesis (see Appendix- Sherman, et al., Molecular Cell, in press, 2010). Defects in this pathway were identified in pilot studies of human B cell lymphomas by ATM or LKB1 repression, or by a recently identified somatic mutation or genetic polymorphism in CRTC2. Much is known about CRTC2 as a regulator of glucose metabolism, and we have now shown that DSBs activate a pathway in GC B cells that inactivates CRTC2. However, no role for CRTC2 in cell differentiation or cancer has been described to date. In new preliminary studies, we discovered a set of CRTC2 bound genes from ChIP-chip in GC B cells that increase rather than decrease in expression with CRTC2 inactivation, suggesting that CRTC2 also has transcriptional repression activity beyond its CREB co-activator function. As a candidate regulator of cell differentiation and cancer, we propose Three New Specific Aims to investigate the role of CRTC2 in controlling B cell fate and function.
In Aim 1, we will determine whether CRTC2 participates in transcriptional repression.
In Aim 2, we will constitutively activate CRTC2 in GC B cells and evaluate effects on B cell differentiation and humoral immunity in vivo.
In aim 3, we will determine whether a new activating CRTC2 alteration is a somatic mutation or germline polymorphism and we will investigate the necessity for CRTC2 inactivation to avoid lymphomagenesis. Overall, our studies expand the role for CRTC2 beyond metabolism and characterize an unexpected new regulator of B cell development and function.

Public Health Relevance

Recently we identified a novel signal transduction pathway that leads from physiologic DNA DSBs in GC B lymphocytes to the inactivation of a transcriptional co-activator of CREB called CTRC2 (aka TORC2) (Sherman, et al., Molecular Cell, in press, 2010). Interestingly, we also discovered that CRTC2 has unexpected transcriptional repression activity, that there is a constitutive-activating alteration in the CRTC2 coding sequence in many human B GC cell lymphomas, and that CRTC2 seems to control B cell fate and function. Our current proposal seeks to establish key mechanistic and molecular determinants of CRTC2 function well beyond its heavily studied role in cell metabolism, to improve our understanding of natural cancer controlling mechanisms and to provide fresh insight for a new, key differentiation factor in B lymphocytes.

National Institute of Health (NIH)
Research Project (R01)
Project #
Application #
Study Section
Cancer Molecular Pathobiology Study Section (CAMP)
Program Officer
Howcroft, Thomas K
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Los Angeles
Schools of Medicine
Los Angeles
United States
Zip Code
Pate, Kira T; Stringari, Chiara; Sprowl-Tanio, Stephanie et al. (2014) Wnt signaling directs a metabolic program of glycolysis and angiogenesis in colon cancer. EMBO J 33:1454-73
Senese, S; Lo, Y C; Huang, D et al. (2014) Chemical dissection of the cell cycle: probes for cell biology and anti-cancer drug development. Cell Death Dis 5:e1462
Chen, Yue; Chung, Aram J; Wu, Ting-Hsiang et al. (2014) Pulsed laser activated cell sorting with three dimensional sheathless inertial focusing. Small 10:1746-51
TeSlaa, Tara; Teitell, Michael A (2014) Techniques to monitor glycolysis. Methods Enzymol 542:91-114
Chen, Yue; Wu, Ting-Hsiang; Kung, Yu-Chun et al. (2013) 3D pulsed laser-triggered high-speed microfluidic fluorescence-activated cell sorter. Analyst 138:7308-15
Dabir, Deepa V; Hasson, Samuel A; Setoguchi, Kiyoko et al. (2013) A small molecule inhibitor of redox-regulated protein translocation into mitochondria. Dev Cell 25:81-92
Wang, Geng; Shimada, Eriko; Zhang, Jin et al. (2012) Correcting human mitochondrial mutations with targeted RNA import. Proc Natl Acad Sci U S A 109:4840-5
Wu, Ting-Hsiang; Chen, Yue; Park, Sung-Yong et al. (2012) Pulsed laser triggered high speed microfluidic fluorescence activated cell sorter. Lab Chip 12:1378-83
Sherman, Mara H; Bassing, Craig H; Teitell, Michael A (2011) Regulation of cell differentiation by the DNA damage response. Trends Cell Biol 21:312-9
Zhang, Jin; Khvorostov, Ivan; Hong, Jason S et al. (2011) UCP2 regulates energy metabolism and differentiation potential of human pluripotent stem cells. EMBO J 30:4860-73

Showing the most recent 10 out of 52 publications