Proc Natl Acad Sci U S A. 2003 Apr 15;100(:4616-21. Epub 2003 Apr 4.

Erratum in:
Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8607.

Identification of a small molecule inhibitor of the hedgehog signaling pathway: effects on basal cell carcinoma-like lesions.

Williams JA, Guicherit OM, Zaharian BI, Xu Y, Chai L, Wichterle H, Kon C, Gatchalian C, Porter JA, Rubin LL, Wang FY.

Curis Incorporated, 61 Moulton Street, Cambridge, MA 02138, USA.

The link between basal cell carcinoma (BCC) and aberrant activation of the Hedgehog (Hh) signaling pathway has been well established in humans and in mouse models. Here we report the development of assays, including two novel in vitro BCC models, which allowed us to screen for Hh inhibitors and test their validity as potential treatments for BCC. We identified a novel small molecule Hh inhibitor (CUR61414) that can block elevated Hh signaling activity resulting from oncogenic mutations in Patched-1. Moreover, CUR61414 can suppress proliferation and induce apoptosis of basaloid nests in the BCC model systems, whereas having no effect on normal skin cells. These findings directly demonstrate that the use of Hh inhibitors could be a valid therapeutic approach for treating BCC.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12679522&query_hl=10&itool=pubmed_docsum

J Biol. 2002 Nov 6;1(2):10.

Small-molecule modulators of Hedgehog signaling: identification and characterization of Smoothened agonists and antagonists.

Frank-Kamenetsky M, Zhang XM, Bottega S, Guicherit O, Wichterle H, Dudek H, Bumcrot D, Wang FY, Jones S, Shulok J, Rubin LL, Porter JA.

Curis, Inc., 61 Moulton Street, Cambridge, MA 02138, USA.

BACKGROUND: The Hedgehog (Hh) signaling pathway is vital to animal development as it mediates the differentiation of multiple cell types during embryogenesis. In adults, Hh signaling can be activated to facilitate tissue maintenance and repair. Moreover, stimulation of the Hh pathway has shown therapeutic efficacy in models of neuropathy. The underlying mechanisms of Hh signal transduction remain obscure, however: little is known about the communication between the pathway suppressor Patched (Ptc), a multipass transmembrane protein that directly binds Hh, and the pathway activator Smoothened (Smo), a protein that is related to G-protein-coupled receptors and is capable of constitutive activation in the absence of Ptc. RESULTS: We have identified and characterized a synthetic non-peptidyl small molecule, Hh-Ag, that acts as an agonist of the Hh pathway. This Hh agonist promotes cell-type-specific proliferation and concentration-dependent differentiation in vitro, while in utero it rescues aspects of the Hh-signaling defect in Sonic hedgehog-null, but not Smo-null, mouse embryos. Biochemical studies with Hh-Ag, the Hh-signaling antagonist cyclopamine, and a novel Hh-signaling inhibitor Cur61414, reveal that the action of all these compounds is independent of Hh-protein ligand and of the Hh receptor Ptc, as each binds directly to Smo. CONCLUSIONS: Smo can have its activity modulated directly by synthetic small molecules. These studies raise the possibility that Hh signaling may be regulated by endogenous small molecules in vivo and provide potent compounds with which to test the therapeutic value of activating the Hh-signaling pathway in the treatment of traumatic and chronic degenerative conditions.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12437772&query_hl=10&itool=pubmed_docsum

3809
Presentation Title:

Inhibition of the Hedgehog pathway as a therapeutic approach for the treatment of basal cell carcinomas
Presentation Start/End Time:

Tuesday, Apr 04, 2006, 8:00 AM -12:00 PM
Location:

Exhibit Hall, Washington Convention Center
Poster Section:

16Hh pathway with trough values
Poster Board Number:

12
Author Block:

Tracy T. Tang, Derek Marshall, Dongwei Li, Michael Reich, Michelle Gonzales, Rudolph Paladini, Oivin Guicherit, Stephen Gould, Karen Kotkow, Lee Rubin, Jim Marsters, Fred De Sauvage. Genentech, Inc., South San Francisco, CA, Curis, Inc., Cambridge, MA
Inappropriate activation of the Hedgehog pathway in skin causes formation of hair follicle-derived tumors, of which the most clinically significant are basal cell carcinomas (BCCs). BCCs and other hair follicle tumors have been shown to contain a variety of mutations in the Hedgehog pathway that result in target gene induction. We describe here the characterization of a small molecule antagonist of the Hedgehog pathway for the treatment of BCC. To determine the potential therapeutic effectiveness of the Hh antagonist we first used a mouse skin explant assay grown in the presence of recombinant sonic hedgehog or used skin derived from UV-irradiated Ptch heterozygous mice. In both cases, the Hh antagonist was found to inhibit the development or to induce regression of BCC-like lesions. To characterize the ability of topical applications of the antagonist to inhibit the Hedgehog pathway in vivo, a depilatory mouse model was utilized to measure the ability of the compound to repress the Hedgehog pathway in Hedgehog responsive cells present at the base of hair follicles in normal skin (StJacques et al. 1998). We found that the Hedgehog antagonist significantly represses the expression of the Hedgehog target gene Gli1 when topically applied in the in vivo depilatory mouse model. Thus, our data indicate that topical delivery of a Hedgehog pathway antagonist provides a promising therapeutic approach for the treatment of BCC.


97th AACR Annual Meeting
April 1-5, 2006
Washington, DC

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Presentation Title:

Characterization of a Hedgehog pathway antagonist in a mouse medulloblastoma allograft model
Presentation Start/End Time:

Wednesday, Apr 05, 2006, 10:40 AM -10:55 AM
Location:

Room 201, Washington Convention Center
Author Block:

Hua Tian, Derek Marshall, Christina Ahn, Zora Modrusan, Leslie Lee, Lesley Murray, Stephen Gould, Oivin Guicherit, Changgeng Qian, Hui Qu, Guang-Xin Xu, Hank Dudek, Karen Kotkow, Lee Rubin, Frederic De Sauvage. Genentech Inc., South San Francisco, CA, Curis Inc., Cambridge, MA
Constitutive activation of the Hedgehog pathway accounts for 25% of sporadic medulloblastoma, the most common childhood brain cancer. It has been demonstrated previously that treatment of a medulloblastoma mouse model (Ptch1+/- P53-/-) with a Hh pathway antagonist, leads to complete eradication of tumors. In order to further characterize the mechanism of action of Cur-691, we have established an allograft model derived from Ptch1+/- p53+/+ mice and observed total regression of established subcutaneous medulloblastoma allografts following 28 days treatment with Cur-691. Importantly, this effect was found to be durable as no tumor regrowth was noted during 60-day following cessation of treatment. In the current study, we characterized pharmacokinetic pharmacodynamic (PK/PD) profile of Cur-691 within the tumor, evaluated changes in apoptosis and cell proliferation, and performed gene expression microarray analysis to identify the molecular pathways altered by Cur-691 treatment. PK/PD analysis demonstrated that concentrations of Cur-691 found in the tumor correlated with repression of the of less than 1mM. Immuno-fluorescence analysis detected a rapid and progressive increase in cell death and inhibition of cell proliferation confined within the tumor component of the allograft following Cur-691 treatment, indicating that the drug specifically targets Ptch1+/- tumor cells, while leaving the stromal and vasculature components of the allograft intact. In addition to down-regulation of several well-characterized Hh target genes, we also observed profound changes in cell cycle regulation and DNA replication following Cur-691 treatment by microarrays. Many signature genes upregulated in desmoplastic (Hh driven) medulloblastoma are immediately modulated by Cur-691 treatment, further confirming that transcription of these signature genes are driven by Hh signaling. Together these data support targeting the Shh pathway for the treatment of desmoplastic medulloblastoma or other cancer where activation of the Hh pathway has been implicated.


97th AACR Annual Meeting
April 1-5, 2006
Washington, DC