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. The primary end point was reduction in the incidence of new basal-cell carcinomas that were eligible for surgical resection (surgically eligible) with vismodegib versus placebo after 3 months; secondary end points included reduction in the size of existing basal-cell carcinomas. RESULTS In 41 patients followed for a mean of 8 months (range, 1 to 15) after enrollment, the per-patient rate of new surgically eligible basal-cell carcinomas was lower with vismodegib than with placebo (2 vs. 29 cases per group per year, P<0.001), as was the size (percent change from baseline in the sum of the longest diameter) of existing clinically significant basal-cell carcinomas (−65% vs. −11%, P = 0.003). In some patients, all basal-cell carcinomas clinically regressed. No tumors progressed during treatment with vismodegib. Patients receiving vismodegib routinely had grade 1 or 2 adverse events of loss of taste, muscle cramps, hair loss, and weight loss. Overall, 54% of patients (14 of 26) receiving vismodegib discontinued drug treatment owing to adverse events. At 1 month, vismodegib use had reduced the hedgehog target-gene expression by basal-cell carcinoma by 90% (P<0.001) and diminished tumor-cell proliferation, but apoptosis was not affected. No residual basal-cell carcinoma was detectable in 83% of biopsy samples taken from sites of clinically regressed basal-cell carcinomas. CONCLUSIONS Vismodegib reduces the basal-cell carcinoma tumor burden and blocks growth of new basal-cell carcinomas in patients with the basal-cell nevus syndrome. The adverse events associated with treatment led to discontinuation in over half of treated patients. (Funded by Genentech and others; ClinicalTrials.gov number, NCT00957229.)

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The cytochrome P-450 4A (CYP4A)-derived arachidonic acid metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) affects renal tubular and vascular functions and has been implicated in the control of arterial pressure. We examined the effect of antisense oligonucleotide (ODN) to CYP4A1, the low K(m) arachidonic acid omega-hydroxylating isoform, on vascular 20-HETE synthesis, vascular reactivity, and blood pressure in the spontaneously hypertensive rat (SHR). Administration of CYP4A1 antisense ODN decreased mean arterial blood pressure from 137 +/- 3 to 121 +/- 4 mmHg (P < 0.05) after 5 days of treatment, whereas treatment with scrambled antisense ODN had no effect. Treatment with CYP4A1 antisense ODN reduced the level of CYP4A-immunoreactive proteins along with 20-HETE synthesis in mesenteric arterial vessels. Mesenteric arteries from rats treated with antisense ODN exhibited decreased sensitivity to the constrictor action of phenylephrine (EC(50) 0.69 +/- 0.17 vs. 1.77 +/- 0.40 microM). Likewise, mesenteric arterioles from antisense ODN-treated rats revealed attenuation of myogenic constrictor responses to increases of transmural pressure. The decreased vascular reactivity and myogenic responses were reversible with the addition of 20-HETE. These data suggest that CYP4A1-derived 20-HETE facilitates myogenic constrictor responses in the mesenteric microcirculation and contributes to pressor mechanisms in SHR.

20-Hydroxyeicosatetraenoic acid (20-HETE), a potent vasoconstrictor and mediator of the myogenic response, is a major arachidonic acid metabolite in the microvasculature of the rat kidney formed primarily by the cytochrome P-450 (CYP) 4A isoforms, CYP4A1, CYP4A2, and CYP4A3. We examined CYP4A isoform expression and 20-HETE synthesis in microdissected interlobar, arcuate, and interlobular arteries; mRNA for all CYP4A isoforms was identified by RT-PCR. Western blot analysis indicated that the levels of CYP4A2/4A3-immunoreactive protein increased with decreased arterial diameter, whereas those of CYP4A1-immunoreactive protein remained unchanged. 20-HETE synthesis was the highest in the interlobular arteries (17 +/- 1.62 nmol. mg(-1). h(-1)) and, like CYP4A2/4A3-immunoreactive protein, decreased with increasing vessel diameter (4.5 +/- 1.21, 2.65 +/- 0.58, and 0.81 +/- 0.14 nmol. mg(-1). h(-1) in the arcuate, interlobar, and segmental arteries, respectively). 20-HETE synthesis in the renal artery and the abdominal aorta was undetectable. The observed decreased immunoreactivity of NADPH-cytochrome P-450 (c) oxidoreductase with increased arterial diameter provided a possible explanation for the decreased capacity to generate 20-HETE in the large arteries. The increase in CYP4A isoform expression and 20-HETE synthesis with decreasing diameter along the preglomerular arteries and the potent biological activity of 20-HETE underscore the significance of 20-HETE as a modulator of renal hemodynamics.

Hypertension is a leading cause of cardiovascular, cerebral, and renal disease morbidity and mortality, and epidemiological evidence suggests a role for sex-dependent mechanisms in the pathophysiology of hypertension. We show here that treatment of rats with 5␣-dihydrotestosterone increases the activity of the kidney arachidonate /-1 hydroxylase and the biosynthesis of 20-HETE (165 and 177% of control untreated male and female rats, respectively) and raises the systolic blood pressures of male and females rats by 46 and 57 mmHg, respectively. These androgen effects are associated with an upregulation in the kidney levels of CYP 4A8 mRNA and a decrease in CYP 4A1 transcripts. Dissected renal microvessels, the target tissue for most of the prohypertensive actions of 20-HETE, show an androgen-dependent upregulation of vascular CYP 4A8 mRNA and a fourfold increase in 20-HETE synthase activity. We propose that androgens regulate renal function and systemic blood pressure through a combination of transcriptional and hemodynamic mechanisms that are ultimately responsible for the regulation of renovascular tone and function. P-450 eicosanoids; androgens; CYP 4A8A NOW CONSIDERABLE BODY of evidence shows that microsomal P-450s (CYPs) participate in the in vivo metabolism of arachidonic acid (AA) and that products of this P-450-catalyzed pathway are in vitro modulators of renal ion transport and vascular reactivity and may be involved in the regulation of systemic blood pressure (3, 4,22,29). During catalytic turnover, the P-450 monooxygenase(s) metabolize AA via /-1 hydroxylation (AA /-1 hydroxylase) to 19-and 20-HETE and/or epoxidation (AA epoxygenase) to 5,8,11,or 14,5). Recombinant CYPs 4A1, 4A2, 4A8, and to a lesser extent 4A3, support the hydroxylation of AA to either 20-HETE or to mixtures of 16,19,31). All four CYP 4A isoforms are expressed in the male rat kidney (4,16,19,31), with CYPs 4A1 and 4A2/4A3 characterized as the predominant microsomal AA /-1 hydroxylases (16). The transcriptional regulation of rat CYPs P-450 4A1 and 4A2/4A3 by the peroxisomal proliferator activated receptor-␣ (45), as well as the sexually dimorphic, testosterone-sensitive expression of rat CYPs 4A2 and 4A8 and of murine Cyp 4a12, has been reported (18,20,40,42).Studies with the spontaneously hypertensive-Wistar Kyoto (SHR/WKY) rat model of spontaneous hypertension, an extensively characterized model of genetic hypertension (29), suggest a role for renal CYP 4As in the pathophysiology of the disease (3, 29). Thus based on 1) temporal associations between the increases in blood pressure, renal CYP 4A expression and 20-HETE formation (3, 29), 2) experimental manipulations of CYP 4A activity and/or expression (29,32,43), and 3)

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare premature aging disorder caused by a de novo heterozygous point mutation G608G (GGC>GGT) within exon 11 of LMNA gene encoding A-type nuclear lamins. This mutation elicits an internal deletion of 50 amino acids in the carboxyl-terminus of prelamin A. The truncated protein, progerin, retains a farnesylated cysteine at its carboxyl terminus, a modification involved in HGPS pathogenesis. Inhibition of protein farnesylation has been shown to improve abnormal nuclear morphology and phenotype in cellular and animal models of HGPS. We analyzed global gene expression changes in fibroblasts from human subjects with HGPS and found that a lamin A-Rb signaling network is a major defective regulatory axis. Treatment of fibroblasts with a protein farnesyltransferase inhibitor reversed the gene expression defects. Our study identifies Rb as a key factor in HGPS pathogenesis and suggests that its modulation could ameliorate premature aging and possibly complications of physiological aging.

Purpose: GDC-0449 (Genentech) is a new hedgehog pathway inhibitor that has been shown in a Phase I trial to reduce locally advanced/metastatic BCCs. We tested the efficacy of GDC-0449 for BCC prevention in a randomized, double-blind, placebo-controlled trial in patients with Basal Cell Nevus Syndrome (BCNS). Methods: We enrolled 41 BCNS patients from 3 clinical centers from September 2009 to January 2011. Subjects were randomized 2:1 to receive once daily oral GDC-0449 (150 mg) or placebo. The primary endpoint was to assess the number of new surgically eligible BCCs per month after 3 months; secondary endpoints included assessment of the change in size of existing BCCs and safety/tolerability. Results: 36 subjects (24 GDC-0449, 12 placebo) have been enrolled for greater than 1 month. Upon review of results at the interim analysis, the DSMB ended the placebo arm of the trial due to statistically significant differences between the 2 groups. Subjects treated with GDC-0449 developed 0.07 new BCCs per month vs. 1.74 BCCs per month for those receiving placebo (p&lt;0.0001). The change from baseline in the aggregate size of existing BCCs was −24 cm vs. −3 cm for GDC-0449 and placebo, respectively (p=0.006). Some subjects achieved near complete remission with no BCC developing resistance. Common grade 1–2 adverse events (GDC-0449 vs. placebo) included taste loss (83% vs. 8%), muscle cramps (67% vs. 8%), and weight loss (50% vs. 8%). Two GDC-0449 subjects experienced grade 3–4 adverse events (muscle cramp, suicide attempt). Overall 20% of GDC-0449 subjects discontinued drug participation due to adverse events. BCC samples from 23 subjects treated with GDC-0449 or placebo were available for molecular analysis. The anti-BCC efficacy of GDC-0449 was associated with on-target reduction of the Hedgehog pathway as Gli1 mRNA levels were decreased by 200-fold (p&lt;0.001) after 1month in BCCs. Gli1 mRNA levels were not changed in BCCs from placebo subjects. GDC-0449 also decreased tumor proliferation (Ki67) but had no effect on apoptosis (CC3). Biopsies of lesions taken after 3 months of GDC-0449 showed histologic clearance in 7 out of 11 samples. Conclusion: GDC-0449 has anti-BCC efficacy in BCNS patients and may be a potential new drug for BCC prevention and treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-1. doi:10.1158/1538-7445.AM2011-LB-1

The propagation of HIV-1 is driven in part by cell-to-cell transmission most frequently observed in dendritic cells (DC) and their subsets-one of the earliest immune cells likely to encounter HIV-1 during acute infection at mucosal surfaces. DCs are capable of highly effective viral transfer to target CD4+ T-cells across the virological synapse, a specialised virus-induced cell junction, which enables widespread viral dissemination and accelerated disease progression. Our previous findings have implicated a major role for cytokines and chemokines in the infection and transmission of HIV-1 from DC subsets, though a global study of their molecular functions has yet to be completed. In this study, we screened 319 individual genes using the Human ON-TARGET plus SMARTpool cytokine & chemokine siRNA library to investigate the differential effects on HIV-1 transfer from monocyte-derived DCs (MDDC) to a CD4+ SupT1 T-lymphoblastic cell line. Using integrative, data-driven approaches we successfully identified several cytokine superfamilies with potent restrictive properties against HIV-1 trans-infection from MDDC to SupT1. The activities of these candidates were validated using three key loss-of-function assays including genetic downregulation, neutralisation by biologics and pharmacological inhibition in trans-to both SupT1 and autologous CD4+ T-cells. Disruption of specific cytokine-driven mechanisms in MDDC results in dramatic changes in the capacity for cell-to-cell transfer to CD4+ T-cells. These findings add to a growing body of evidence linking the cytokine network which will inform novel therapeutic strategies against early-stage HIV-1 infection and transmission