Phase 2 Trial of Topical Application of the Hedgehog Inhibitor Patidegib in Patients With Gorlin Syndrome.

Background: Patients with Gorlin (basal cell nevus) syndrome (GS) have numerous phenotypic abnormalities due to over-activity of the hedgehog (HH) signaling pathway, most commonly due to a heritable mutation in the PTCH1 gene, which encodes a major inhibitor of this pathway. HH inhibitors (HHi) taken orally can reverse some of the manifestations, most prominent of which is the development of numerous cutaneous basal cell carcinomas (BCCs). In order to improve the benefit:risk ratio, we have developed a gel containing a small cyclopamine-derived molecule that can be applied topically in expectation that this mode of delivery can reduce the burden of BCCs without producing the systemic adverse effects that cause patients to stop treatment with oral HHis.

Ultraviolet Radiation Inhibits Mammary Carcinogenesis in an ER-Negative Murine Model by a Mechanism Independent of Vitamin D.

Three decades ago, the Garlands postulated that vitamin D produced in the skin by ultraviolet radiation (UVR)-induced conversion of 7-dehydrocholesterol to pre-D has anticancer effects, thus triggering more than 9,500 publications on D and cancer. Here, we report that UVR treatment of transgenic mice of the well-established C3(1)/SV40 Tag mammary cancer model significantly inhibits both autochthonous carcinogenesis and allograft tumor growth, but in contrast neither dietary nor topical D influences mammary carcinogenesis in this specific mouse model. Furthermore, UVR's inhibitory effects occur irrespective of whether or not the treatment increases circulating D in the mice.

Noncanonical hedgehog pathway activation through SRF-MKL1 promotes drug resistance in basal cell carcinomas.

Hedgehog pathway-dependent cancers can escape Smoothened (SMO) inhibition through mutations in genes encoding canonical hedgehog pathway components; however, around 50% of drug-resistant basal cell carcinomas (BCCs) lack additional variants of these genes. Here we use multidimensional genomics analysis of human and mouse drug-resistant BCCs to identify a noncanonical hedgehog activation pathway driven by the transcription factor serum response factor (SRF). Active SRF along with its coactivator megakaryoblastic leukemia 1 (MKL1) binds DNA near hedgehog target genes and forms a previously unknown protein complex with the hedgehog transcription factor glioma-associated oncogene family zinc finger-1 (GLI1), causing amplification of GLI1 transcriptional activity.

Genomic Stability in Syndromic Basal Cell Carcinoma.

Basal cell cancers (BCCs) are characterized by upregulation of Hedgehog pathway through loss of PTCH1 or activation of SMO, and SMO inhibitors, such as vismodegib, are effective therapies for advanced BCCs. Although most BCCs are sporadic, rare individuals with basal cell nevus syndrome (BCNS) harbor germline defects in PTCH1 and develop up to hundreds of tumors that are histopathologically indistinguishable from sporadic BCCs. Interestingly, BCNS-BCCs are more responsive to SMO inhibitors than sporadic BCCs, with minimal development of resistance.

Combined inhibition of atypical PKC and histone deacetylase 1 is cooperative in basal cell carcinoma treatment.

Advanced basal cell carcinomas (BCCs) circumvent Smoothened (SMO) inhibition by activating GLI transcription factors to sustain the high levels of Hedgehog (HH) signaling required for their survival. Unfortunately, there is a lack of efficacious therapies. We performed a gene expression-based drug repositioning screen in silico and identified the FDA-approved histone deacetylase (HDAC) inhibitor, vorinostat, as a top therapeutic candidate.

Vitamin D Produced by Skin Exposure to UVR Inhibits Murine Basal Cell Carcinoma Carcinogenesis.

The effect of UVR on human basal cell carcinoma (BCC) epidemiology is complex-the incidence rises until approximately 30,000 hours of lifetime sunlight exposure and then plateaus. We hypothesize that UVR has opposing effects on BCC carcinogenesis-stimulatory via mutagenesis and inhibitory via production of hedgehog-inhibiting vitamin D (D). We find that UVR exposure of ionizing radiation-treated Ptch1 mice accelerates BCC carcinogenesis in male mice, in which UVR does not produce D.

Attenuation of UVR-induced vitamin D synthesis in a mouse model deleted for keratinocyte lathosterol 5-desaturase.

The lower risk of some internal cancers at lower latitudes has been linked to greater sun exposure and consequent higher levels of ultraviolet radiation (UVR)-produced vitamin D (D). To separate the experimental effects of sunlight and of all forms of D, a mouse in which UVR does not produce D would be useful. To this end we have generated mice carrying a modified allele of sterol C5-desaturase (Sc5d), the gene encoding the enzyme that converts lathosterol to 7-dehydrocholesterol (7-DHC), such that Sc5d expression can be inactivated using the Cre/lox site-specific recombination system.

Risk Factors for Basal Cell Carcinoma Among Patients With Basal Cell Nevus Syndrome: Development of a Basal Cell Nevus Syndrome Patient Registry.

Importance: Patients with basal cell nevus syndrome (BCNS) have a greater risk of developing numerous basal cell carcinomas (BCCs). Risk factors influencing the wide variation in tumor burden are poorly understood.

Objective: To describe the burden of BCCs in patients with BCNS in the United States and identify potential risk factors for BCCs.

Inhibition of the hedgehog pathway in patients with basal-cell nevus syndrome: final results from the multicentre, randomised, double-blind, placebo-controlled, phase 2 trial.

Background: Aberrant hedgehog signalling underlies the development of basal-cell carcinomas. We previously reported the interim analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial in patients with the basal-cell nevus (Gorlin) syndrome indicating that the smoothened inhibitor vismodegib reduces basal-cell carcinoma tumour burden and prevents new basal-cell carcinoma growth in patients with basal-cell nevus syndrome. We report the final results of this 36 month trial.

Posaconazole, a Second-Generation Triazole Antifungal Drug, Inhibits the Hedgehog Signaling Pathway and Progression of Basal Cell Carcinoma.

Deregulation of Hedgehog (Hh) pathway signaling has been associated with the pathogenesis of various malignancies, including basal cell carcinomas (BCC). Inhibitors of the Hh pathway currently available or under clinical investigation all bind and antagonize Smoothened (SMO), inducing a marked but transient clinical response. Tumor regrowth and therapy failure were attributed to mutations in the binding site of these small-molecule SMO antagonists.

The use of vismodegib to shrink keratocystic odontogenic tumors in patients with basal cell nevus syndrome.

Importance: Keratocystic odontogenic tumors (KCOTs) of the jaw affect more than 65% of patients with basal cell nevus syndrome (BCNS). Surgery frequently causes facial disfigurement and is not always curative. Most BCNS-related and some sporadic KCOTs have malignant activation of the Hedgehog signaling pathway.

PI3K-AKT signaling is a downstream effector of retinoid prevention of murine basal cell carcinogenesis.

Basal cell carcinoma (BCC) is the most common human cancer. We have demonstrated previously that topical application of the retinoid prodrug tazarotene profoundly inhibits murine BCC carcinogenesis via retinoic acid receptor γ-mediated regulation of tumor cell transcription. Because topical retinoids can cause adverse cutaneous effects and because tumors can develop resistance to retinoids, we have investigated mechanisms downstream of tazarotene's antitumor effect in this model.

Tazarotene: randomized, double-blind, vehicle-controlled, and open-label concurrent trials for basal cell carcinoma prevention and therapy in patients with basal cell nevus syndrome.

Sporadic human basal cell carcinomas (BCC) are generally well managed with current surgical modalities. However, in the subset of high-risk patients predisposed to developing large numbers of BCCs, there is an unmet need for effective, low-morbidity chemoprevention. This population includes fair-skinned patients with extensive sun exposure and those with genodermatoses such as the basal cell nevus (Gorlin) syndrome (BCNS).

First-in-human trial of nanoelectroablation therapy for basal cell carcinoma: proof of method.

This nanoelectroablation therapy effectively treats subdermal murine allograft tumors, autochthonous basal cell carcinoma (BCC) tumors in Ptch1+/-K14-Cre-ER p53 fl/fl mice, and UV-induced melanomas in C57/BL6 HGF/SF mice. Here, we described the first human trial of this modality. We treated 10 BCCs on three subjects with 100-1000 electric pulses 100 ns in duration, 30 kV/cm in amplitude, applied at 2 pulses per second.

Skin cancer: Basal cell carcinoma--pay your money, take your choice.

Superficial basal cell carcinomas are a common challenge in clinical dermatology because they are frequent and surgical approaches tend to scar. A large randomized trial comparing three nonsurgical approaches has shown that all had similar clinical outcomes - so, you pay your money and take your choice.

Itraconazole and arsenic trioxide inhibit Hedgehog pathway activation and tumor growth associated with acquired resistance to smoothened antagonists.

Recognition of the multiple roles of Hedgehog signaling in cancer has prompted intensive efforts to develop targeted pathway inhibitors. Leading inhibitors in clinical development act by binding to a common site within Smoothened, a critical pathway component. Acquired Smoothened mutations, including SMO(D477G), confer resistance to these inhibitors.

Nanoelectroablation therapy for murine basal cell carcinoma.

When skin tumors are exposed to non-thermal, low energy, nanosecond pulsed electric fields (nsPEF), apoptosis is initiated both in vitro and in vivo. This nanoelectroablation therapy has already been proven effective in treating subdermal murine allograft tumors. We wanted to determine if this therapy would be equally effective in the treatment of autochthonous BCC tumors in Ptch1(+/-)K14-Cre-ER p53 fl/fl mice.

Inhibiting the hedgehog pathway in patients with the basal-cell nevus syndrome.

Background: Dysregulated hedgehog signaling is the pivotal molecular abnormality underlying basal-cell carcinomas. Vismodegib is a new orally administered hedgehog-pathway inhibitor that produces objective responses in locally advanced and metastatic basal-cell carcinomas.

Methods: We tested the anti-basal-cell carcinoma efficacy of vismodegib in a randomized, double-blind, placebo-controlled trial in patients with the basal-cell nevus syndrome at three clinical centers from September 2009 through January 2011.

Establishment of murine basal cell carcinoma allografts: a potential model for preclinical drug testing and for molecular analysis.

Dysregulated hedgehog (HH) signaling has been found in numerous cancers, suggesting that therapeutic targeting of this pathway may be useful versus a wide range of cancers. Basal cell carcinoma (BCC) is an excellent model system for studying the influence of the HH pathway on carcinogenesis because aberrant activation of HH signaling is crucial not only for the development of but also the maintenance of BCC. Genetically engineered BCC mouse models provide one important tool for the study of the biology of human BCCs and for evaluating therapeutic interventions, as these mice produce multiple genetically defined tumors within a relatively short period of time.

Targeting superficial or nodular Basal cell carcinoma with topically formulated small molecule inhibitor of smoothened.

Purpose: Inappropriate activation of the Hedgehog (Hh) signaling pathway in skin is critical for the development of basal cell carcinomas (BCC). We have investigated the anti-BCC efficacy of topically-applied CUR61414, an inhibitor of the Hh signal transduction molecule Smoothened.

Experimental Design: In preclinical studies, we used a depilatory model to evaluate the ability of topical formulations of CUR61414 to repress Hh responsive cells found at the base of hair follicles in normal skin.