Translating cyclooxygenase signaling in patch heterozygote mice into a randomized clinical trial in basal cell carcinoma

Shh and p50/Bcl3 signaling crosstalk drives pathogenesis of BCCs in Gorlin syndrome

Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disorder that is due, in large measure, to aberrant Shh signaling driven by mutations in the tumor suppressor gene Ptch1. Here, we describe the development of Ptch1+/-/ SKH-1 mice as a novel model of this disease. These animals manifest many features of NBCCS, including developmental anomalies and are remarkably sensitive to both ultraviolet (UVB) and ionizing radiation that drive the development of multiple BCCs. Just as in patients with NBCCS, Ptch1+/-/SKH-1 also spontaneously develops BCCs and other neoplasms such as rhabdomyomas/rhabdomyosarcomas. Administration of smoothened inhibitors (vismodegib/itraconazole/cyclopamine) or non-steroidal anti-inflammatory drug (sulindac/sulfasalazine) each result in partial resolution of BCCs in these animals. However, combined administration of these agents inhibits the growth of UVB-induced BCCs by >90%. Employing small molecule- and decoy-peptide-based approaches we further affirm that complete remission of BCCs could only be achieved by combined inhibition of p50-NFκB/Bcl3 and Shh signaling. We posit that Ptch1+/-/SKH-1 mice are a novel and relevant animal model for NBCCS. Understanding mechanisms that govern genetic predisposition to BCCs should facilitate our ability to identify and treat NBCCS gene carriers, including those at risk for sporadic BCCs while accelerating development of novel therapeutic modalities for these patients.

Vitamin D deficiency among northern Native Peoples: a real or apparent problem?

Vitamin D deficiency seems to be common among northern Native peoples, notably Inuit and Amerindians. It has usually been attributed to: (1) higher latitudes that prevent vitamin D synthesis most of the year; (2) darker skin that blocks solar UVB; and (3) fewer dietary sources of vitamin D. Although vitamin D levels are clearly lower among northern Natives, it is less clear that these lower levels indicate a deficiency. The above factors predate European contact, yet pre-Columbian skeletons show few signs of rickets-the most visible sign of vitamin D deficiency. Furthermore, because northern Natives have long inhabited high latitudes, natural selection should have progressively reduced their vitamin D requirements. There is in fact evidence that the Inuit have compensated for decreased production of vitamin D through increased conversion to its most active form and through receptors that bind more effectively. Thus, when diagnosing vitamin D deficiency in these populations, we should not use norms that were originally developed for European-descended populations who produce this vitamin more easily and have adapted accordingly.

New agents for prevention of ultraviolet-induced nonmelanoma skin cancer

With the incidence of nonmelanoma skin cancer on the rise, current prevention methods, such as the use of sunscreens, have yet to prove adequate to reverse this trend. There has been considerable interest in identifying compounds that will inhibit or reverse the biochemical changes required for skin cancers to develop, either by pharmacologic intervention or by dietary manipulation. By targeting different pathways identified as important in the pathogenesis of nonmelanoma skin cancers, a combination approach with multiple agents or the addition of chemopreventative agents to topical sunscreens may offer the potential for novel and synergistic therapies in treating nonmelanoma skin cancer.

Sulfonamide derivatives of styrylheterocycles as a potent inhibitor of COX-2-mediated prostaglandin E2 production

The overproduction of prostaglandin E(2) (PGE(2)) plays an important role in a variety of pathophysiological processes including inflammation and carcinogenesis. Therefore, the modulation of PGE(2) production is a promising target in the design of chemotherapeutic agents. In the present study, the inhibitory effects of a series of styrylheterocycles having either a p-SO(2)NH(2) or p-SO(2)Me group on the production of cyclooxygenase-2-mediated PGE(2) were evaluated in lipopolysaccharide-stimulated RAW264.7 murine macrophages. Among the series of styrylheterocycle derivatives, (E)-4-(2-(thiophen-3-yl)vinyl)benzenesulfonamide exhibited a potent inhibitory activity, with an IC(50) value of 0.013 μM. The inhibitory activity against the overproduction of PGE(2) by the active compound was found to be due in part to the suppression of COX-2 mRNA expression.