Testosterone/bicalutamide antagonism at the predicted extracellular androgen binding site of ZIP9.

ZIP9 is a Zn2+ transporter, testosterone receptor, and mediator of signaling events through G-proteins. Despite these pivotal properties, however, its physiological and pathophysiological significance has not yet been comprehensively addressed. Using a cell line that lacks the classical androgen receptor we show that ZIP9-mediated phosphorylation of Erk1/2, CREB, or ATF-1 and expression of claudin-5 and zonula occludens-1 by testosterone can be completely antagonized by bicalutamide (Casodex), an anti-androgen of significant clinical impact. Computational modeling and docking experiments with ZIP9 reveal typical characteristics of ZIP transporters and an extracellular binding site for testosterone capable of accommodating bicalutamide. The presence of this site is verified by our demonstration that the membrane-impermeable testosterone analogue T-BSA-FITC labels the membrane only when ZIP9 is expressed and that this labeling is completely prevented by bicalutamide. The study connects structural features of ZIP9 to its functions and indicates a possible relevance of ZIP9 as a pharmacological target.

Hedgehog Pathway Inhibition for Locally Advanced Periocular Basal Cell Carcinoma and Basal Cell Nevus Syndrome.

PURPOSE: To review our experience treating patients with the Hedgehog pathway inhibitor, vismodegib, in patients with orbital or periocular locally advanced or metastatic basal cell carcinoma (BCC) or basal cell nevus syndrome. DESIGN: Retrospective interventional case series. METHODS: We reviewed all patients with locally advanced or metastatic orbital or periocular BCC or basal cell nevus syndrome treated with the Hedgehog pathway inhibitor, vismodegib, at a comprehensive cancer center from 2009 through 2015. Reviewed data included age; sex; American Joint Commission on Cancer tumor, node, metastasis staging system designation; type and grade of drug-related side effects; response to treatment; duration of follow-up, and status at last follow-up. RESULTS: The study included 10 white men and 2 white women; the median age was 64.5 years. Ten patients had locally advanced BCC; 2 had basal cell nevus syndrome. Among the patients with locally advanced BCC, 5 had T3bN0M0 disease at presentation; 1 each had T3aN0M0, T3bN1M0, T2N1M1, T4N1M1, and T4N2cM1 disease. Overall, 3 patients had a complete response, 6 had a partial response, and 3 had stable disease at last follow-up. Two patients developed progressive disease after a complete response for 38 months and stable disease for 16 months, respectively. All patients developed grade I drug-related adverse effects, most commonly muscle spasms (12 patients), weight loss (10), dysgeusia (9), alopecia (9), decreased appetite (5), and fatigue (4). Five patients developed grade II adverse effects. At last follow-up, none of the 5 patients presenting with T3bN0M0, nor the patient with T3bN1M0 disease, had required orbital exenteration. CONCLUSION: Hedgehog pathway inhibition produces a significant clinical response in most patients with locally advanced or metastatic orbital or periocular BCC or basal cell nevus syndrome and can obviate orbital exenteration in some patients. Drug-related adverse effects are manageable in most patients.

Interaction between AR signalling and CRKL bypasses casodex inhibition in prostate cancer.

The underlying mechanism of failed androgen ablation therapy is unknown. It is recognised that under therapeutic conditions the androgen receptor (AR) remains functionally active independent of hormone stimulation and may function through an alternative pathway. We report a novel cooperative interaction between CRKL (an intracellular signalling adaptor protein) and the AR. We demonstrate by biochemical and genetic approaches that CRKL is associated with the AR complex and is localised in the nucleus of prostate cancer cells and patient tissue biopsies. The interaction between CRKL and the AR is functionally relevant as demonstrated by its presence on the enhancer region of an androgen regulated gene (human Kallikrein-2), its upregulation of PSA, and reduction in AR transactivation following its disruption by siRNA knockdown. In the presence of the AR inhibitor casodex, the expression of CRKL co-stimulated by growth factors is able to rescue AR activity independent of hormone. Our data provides insight on how a non-nuclear factor such as CRKL may interact with the AR complex to bypass hormone dependency by using an alternative growth factor signalling pathway in advanced prostate cancer.

Bicalutamide 80 mg combined with a luteinizing hormone-releasing hormone agonist (LHRH-A) versus LHRH-A monotherapy in advanced prostate cancer: findings from a phase III randomized, double-blind, multicenter trial in Japanese patients.

To compare combination therapy with bicalutamide 80 mg and a luteinizing hormone-releasing hormone agonist (LHRH-A) versus LHRH-A alone in Japanese men with untreated advanced prostate cancer. A total of 205 patients with stage C/D prostate cancer were randomized to either LHRH-A+once-daily oral bicalutamide 80 mg or placebo. Primary study variables have been reported previously. Secondary variables included: time to achieve prostate-specific antigen < or = 4 ng/ml, time-to-treatment failure (TTTF), time-to-disease progression (TTP), overall survival (OS), adverse events and adverse drug reactions. Following combination therapy with bicalutamide 80 mg, there were significant (P<0.001) advantages over LHRH-A alone in terms of TTTF and TTP, but the difference in the interim OS was not statistically significant. First-line combination therapy with bicalutamide 80 mg in Japanese patients with advanced prostate cancer offers significant benefits over LHRH-A alone, with respect to TTTF and TTP. Follow-up for OS continues.