Mutations in components of the Hedgehog (Hh) signal transduction pathway underlie a number of human developmental disorders, and contribute to a diverse array of tumors. Gorlin's syndrome is one example of the role this pathway plays in both development and cancer. Besides numerous developmental abnormalities, individuals afflicted with this disorder have an inherited predisposition to basal cell carcinoma as well as to a variety of primitive neuroectodermal tumors, such as medulloblastoma. Similar components are also found mutated in sporadic forms of these same malignancies, or highly amplified in glioblastoma. Our long-term goals are to elucidate how this signal transduction pathway is usurped in these different human pathologies. Hedgehog signal transduction occurs through a large multi-component microtubule-bound protein complex, that when disrupted blocks signaling. This Hedgehog signaling complex (HSC) is an approximately 1000 kDa multi-protein complex with three known members, the protein kinase Fused (Fu), the transcription factor Cubitus Interuptus (Ci), and the kinesin-like protein Costal2 (Cos2). In addition to Fu, Ci, and Cos2, we hypothesize that the HSC contains a number of as yet unknown, but functionally important protein components. The goals of this project are to identify these components, and evaluate their role in HSC function and organization.
The specific aims of our studies are: 1) Develop an in vitro reconstitution system for members of the HSC using a baculovirus expression system, this will allow us to isolate modified forms of the various HSC components in large amounts for various in vitro studies; 2) Identify additional members of a Hh dependent signaling complex. This will be done through a combination of both affinity and conventional chromatography, as well as using a candidate gene approach. Identifying these other components will provide insight into the role this large protein machine plays in Hh signal transduction. It will also provide the framework necessary to identify the human orthologs of the HSC, and elucidate their role in oncogenesis (in future work).

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Human Embryology and Development Subcommittee 1 (HED)
Program Officer
Gallahan, Daniel L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Cincinnati
Schools of Medicine
United States
Zip Code
Li, Bin; Orton, Darren; Neitzel, Leif R et al. (2017) Differential abundance of CK1? provides selectivity for pharmacological CK1? activators to target WNT-dependent tumors. Sci Signal 10:
Long, Jun; Li, Bin; Rodriguez-Blanco, Jezabel et al. (2014) The BET bromodomain inhibitor I-BET151 acts downstream of smoothened protein to abrogate the growth of hedgehog protein-driven cancers. J Biol Chem 289:35494-502
Li, Bin; Fei, Dennis Liang; Flaveny, Colin A et al. (2014) Pyrvinium attenuates Hedgehog signaling downstream of smoothened. Cancer Res 74:4811-21
Li, Bin; Flaveny, Colin A; Giambelli, Camilla et al. (2014) Repurposing the FDA-approved pinworm drug pyrvinium as a novel chemotherapeutic agent for intestinal polyposis. PLoS One 9:e101969
Robbins, David J; Fei, Dennis Liang; Riobo, Natalia A (2012) The Hedgehog signal transduction network. Sci Signal 5:re6
Singh, Samer; Wang, Zhiqiang; Liang Fei, Dennis et al. (2011) Hedgehog-producing cancer cells respond to and require autocrine Hedgehog activity. Cancer Res 71:4454-63
Farzan, Shohreh F; Stegman, Melanie A; Ogden, Stacey K et al. (2009) A quantification of pathway components supports a novel model of Hedgehog signal transduction. J Biol Chem 284:28874-84
Ogden, Stacey K; Fei, Dennis Liang; Schilling, Neal S et al. (2008) G protein Galphai functions immediately downstream of Smoothened in Hedgehog signalling. Nature 456:967-70
Farzan, Shohreh F; Singh, Samer; Schilling, Neal S et al. (2008) The adventures of sonic hedgehog in development and repair. III. Hedgehog processing and biological activity. Am J Physiol Gastrointest Liver Physiol 294:G844-9
Farzan, Shohreh F; Ascano Jr, Manuel; Ogden, Stacey K et al. (2008) Costal2 functions as a kinesin-like protein in the hedgehog signal transduction pathway. Curr Biol 18:1215-20

Showing the most recent 10 out of 18 publications