The Discovery of N-(1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-5-((6- ((methylamino)methyl)pyrimidin-4-yl)oxy)-1H-indole-1-carboxamide (Acrizanib), a VEGFR-2 Inhibitor Specifically Designed for Topical Ocular Delivery, as a Therapy for Neovascular Age-Related Macular Degeneration

A noninvasive topical ocular therapy for the treatment of neovascular or "wet" age-related macular degeneration would provide a patient administered alternative to the current standard of care, which requires physician administered intravitreal injections. This manuscript describes a novel strategy for the use of in vivo models of choroidal neovascularization (CNV) as the primary means of developing SAR related to efficacy from topical administration. Ultimately, this effort led to the discovery of acrizanib (LHA510), a small-molecule VEGFR-2 inhibitor with potency and efficacy in rodent CNV models, limited systemic exposure after topical ocular administration, multiple formulation options, and an acceptable rabbit ocular PK profile.

Discovery of Oral VEGFR-2 Inhibitors with Prolonged Ocular Retention That Are Efficacious in Models of Wet Age-Related Macular Degeneration

The benefit of intravitreal anti-VEGF therapy in treating wet age-related macular degeneration (AMD) is well established. Identification of VEGFR-2 inhibitors with optimal ADME properties for an ocular indication provides opportunities for dosing routes beyond intravitreal injection. We employed a high-throughput in vivo screening strategy with rodent models of choroidal neovascularization and iterative compound design to identify VEGFR-2 inhibitors with potential to benefit wet AMD patients. These compounds demonstrate preferential ocular tissue distribution and efficacy after oral administration while minimizing systemic exposure.

Lack of involvement of CEP adducts in TLR activation and in angiogenesis

Proteins that are post-translationally adducted with 2-(ω-carboxyethyl)pyrrole (CEP) have been proposed to play a pathogenic role in age-related macular degeneration, by inducing angiogenesis in a Toll Like Receptor 2 (TLR2)-dependent manner. We have investigated the involvement of CEP adducts in angiogenesis and TLR activation, to assess the therapeutic potential of inhibiting CEP adducts and TLR2 for ocular angiogenesis. As tool reagents, several CEP-adducted proteins and peptides were synthetically generated by published methodology and adduction was confirmed by NMR and LC-MS/MS analyses. Structural studies showed significant changes in secondary structure in CEP-adducted proteins but not the untreated proteins. Similar structural changes were also observed in the treated unadducted proteins, which were treated by the same adduction method except for one critical step required to form the CEP group. Thus some structural changes were unrelated to CEP groups and were artificially induced by the synthesis method. In biological studies, the CEP-adducted proteins and peptides failed to activate TLR2 in cell-based assays and in an in vivo TLR2-mediated retinal leukocyte infiltration model. Neither CEP adducts nor TLR agonists were able to induce angiogenesis in a tube formation assay. In vivo, treatment of animals with CEP-adducted protein had no effect on laser-induced choroidal neovascularization. Furthermore, in vivo inactivation of TLR2 by deficiency in Myeloid Differentiation factor 88 (Myd88) had no effect on abrasion-induced corneal neovascularization. Thus the CEP-TLR2 axis, which is implicated in other wound angiogenesis models, does not appear to play a pathological role in a corneal wound angiogenesis model. Collectively, our data do not support the mechanism of action of CEP adducts in TLR2-mediated angiogenesis proposed by others.

Reliability of the mouse model of choroidal neovascularization induced by laser photocoagulation

PURPOSE

We attempted to reproduce published studies that evaluated whether the following factors influence choroidal neovascularization (CNV) induced by laser photocoagulation in murine retinas: small interfering RNA (siRNA), cobra venom factor, complement factors C3 and C5, and complement receptor C5aR. In addition, we explored whether laser-induced CNV in mice was influenced by the vendor of origin of the animals.

METHODS

Reagents or genotypes reported by others to influence CNV in this model were assessed using our standard procedures. Retrospective analyses of control or placebo mice in many experiments were done to evaluate whether the CNV area induced by laser photocoagulation varied according to vendor.

RESULTS

Administration of the following agents did not have a substantial impact on the CNV induced by laser burns in mice: siRNA, low-molecular-weight inhibitor of the C5a receptor (PMX53), or cobra venom factor. Jackson Laboratory (JAX) mice lacking either C3 or C5 had increased neovascularization compared to non-littermate JAX wild-type controls. Taconic mice lacking C3 had reduced CNV compared to non-littermate Taconic wild-type control mice. A retrospective analysis of vehicle-treated wild-type C57BL/6 mice used as controls across 132 experiments conducted from 2007 to 2010 revealed that mice purchased from JAX or from Charles River produced less neovascularization than mice from Taconic.

CONCLUSIONS

We present our recommended methods for conducting experiments with the mouse laser-induced CNV model to enhance reproducibility and minimize investigator bias.

Pharmacologic uncoupling of angiogenesis and inflammation during initiation of pathological corneal neovascularization

Pathological neovascularization occurs when a balance of pro- and anti-angiogenic factors is disrupted, accompanied by an amplifying inflammatory cascade. However, the interdependence of these responses and the mechanism triggering the initial angiogenic switch have remained unclear. We present data from an epithelial debridement model of corneal neovascularization describing an initial 3-day period when a substantial component of neovascular growth occurs. Administration of selective inhibitors shows that this initial growth requires signaling through VEGFR-2 (vascular endothelial growth factor receptor-2), independent of the accompanying inflammatory response. Instead, increased VEGF production is found prominently in repair epithelial cells and is increased prior to recruitment of neutrophil/granulocytes and macrophage/monocytes. Consequently, early granulocyte and monocyte depletion has little effect on corneal neovascularization outgrowth. These data indicate that it is possible to pharmacologically uncouple these mechanisms during early injury-driven neovascularization in the cornea and suggest that initial tissue responses are coordinated by repair epithelial cells.

Coping with bladder exstrophy: diverse results from early attempts at functional urinary tract surgery

OBJECTIVES

To report the long-term surgical outcome in a group of patients with bladder exstrophy treated from 1960 to 1982, and to assess physical health, social integration and sexual function, as attempts at functional closure during the development of this surgery resulted in patients with differing surgical status of the genitourinary organs.

PATIENTS AND METHODS

A review of medical record archives revealed 36 patients; of these, seven had died, six were untraceable and six declined to participate, leaving 15 evaluable subjects (seven men and eight women, mean age at follow-up, 35 years). Data were collected from medical records and direct interviews were conducted using a semi-structured questionnaire, after obtaining informed consent. The Short Form-36 (SF-36) v2 Health Survey instrument was used to assess health and well-being.

RESULTS

Three patients have retained the use of their bladder, and 11 had initial bladder closure but required (at a mean age of 3.1 years) various urinary diversions. Eight patients had a pelvic osteotomy. Of 27 functioning renal units, 25 are in reasonable to good condition. Six men and six women had genital reconstruction. Four men are capable of penetrative intercourse and ejaculate; six women manage penetrative intercourse and five have orgasms. All patients attended mainstream school and 13 achieved examination success. Nine patients took vocational training and 11 work full-time. Five patients are married and five are in long-term relationships. Two men have achieved three pregnancies and one women has had a child. The mean total SF-36 score (maximum 3600) was 2763 in men and 2235 in women.

CONCLUSIONS

Surgery for bladder exstrophy has been developing for more than 40 years and the legacy of early attempts at functional closure is a population of adults who have a diversity of lower urinary tracts, good preservation of renal function overall and acceptable sexual function. They are usually robust, healthy and well-adjusted individuals functioning well in society, often in full-time employment and long-term relationships. Adolescent follow-up must be clearly focused, incorporating a multidisciplinary team approach to facilitate a seamless transition into adulthood.

Heat shock protein expression independently predicts clinical outcome in prostate cancer

Heat shock proteins (hsps) occupy a central role in the regulation of intracellular homeostasis, and differential expression of individual hsps occurs in a broad range of neoplastic processes. This study was performed to test the hypothesis that the particular patterns by which individual hsps become specifically modulated in human prostate cancers are correlated with behavioral phenotype and hence may be of value in determining the most appropriate clinical management of individual patients. Monoclonal antibodies specific for each hsp protein were used to assess expression of hsp27, hsp60, and hsp70 in formalin-fixed, paraffin wax-embedded, archival tissue specimens of early prostatic adenocarcinomas (pT1-2N0M0) removed at radical prostatectomy (n = 25) and in advanced cancers (n = 95) identified at transurethral resection of prostate (TURP). These findings were compared with similar data from control prostates (n = 10) removed at primary cystectomy for urinary bladder neoplasia not involving the prostate and also at TURP for benign prostatic hyperplasia (n = 50). Western blotting of whole cell lysates derived from established human prostatic epithelial cell lines PNT2, LNCaP, DU145, and PC3 was compared with expression of hsps by the primary human tissues. This study found that early in situ neoplastic transformation of normal prostatic epithelium was consistently associated with loss of hsp27 expression and that the level of hsp27 expression by individual prostate cancers was correlated with their Gleason grade. In advanced cancers, hsp27 expression was invariably associated with poor clinical outcome (P = 0.0001). Data from cell lines supported the primary tissue findings, with elevated hsp27 expression only in aggressive malignant cell lines and androgen-insensitive cell lines. Expression of hsp60 was significantly increased in both early and advanced prostate cancer when compared with nonneoplastic prostatic epithelium (P < 0.0001), as well as in malignant prostate cancer cell lines. Expression of hsp70 was unaltered in early prostate cancers when compared with nonneoplastic prostatic epithelium but showed a diminished expression in morphologically advanced cancers (P = 0.0029). No consistent correlation was found between levels of hsp60 or hsp70 expression and phenotypic behavior of individual primary prostatic cancers. Thus, patterns of hsp expression have been confirmed to be specifically and consistently modulated in both early and advanced human prostate cancers. Whereas absence of hsp27 is a reliable objective marker of early prostatic neoplasia, reexpression of this protein by an individual invasive prostatic carcinoma invariably heralds poor clinical prognosis. Because this protein has been shown to alter the balance between proliferation and apoptosis, understanding the mechanism(s) by which individual hsps regulate intracellular homeostasis may assist in explaining some key processes that occur during evolution of human prostate cancers. We suggest that hsp27 expression provides novel diagnostic and prognostic information on individual patient survival which, if obtained at the time of primary diagnosis, would assist in determining tumor-specific management strategies. Development of techniques to therapeutically modulate hsp27 expression raises the possibility of novel targeted approaches to regulate this homeostatic mechanism, thus allowing better control over tumor cell proliferation and hence patient survival.

Protein kinase C isoenzyme patterns characteristically modulated in early prostate cancer

Expression of protein kinase C (PKC) isoenzymes -alpha, -beta, -delta, -epsilon, -gamma, -iota, -lambda, -mu, -theta, and -zeta, and of their common receptor for activated C-kinase (RACK)-1, was determined immunohistochemically using specific antibodies in formalin-fixed and paraffin-embedded specimens of early prostatic adenocarcinomas (n = 23) obtained at radical prostatectomy. Expression of each isoenzyme by malignant tissues was compared with nonneoplastic prostate tissues removed at radical cystectomy (n = 10). The most significant findings were decreased PKC-beta expression in early neoplasia when compared to benign epithelium (P < 0.0001), together with a reciprocal increase in expression of PKC-epsilon (P < 0.0001). Detectable levels of PKC-alpha and PKC-zeta were also significantly increased in the cancers (P = 0.045 and P = 0.015 respectively) but did not correlate with either PKC-beta or PKC-epsilon for individual cases. Alterations in the levels of the four PKC isoenzymes occurred specifically and consistently during the genesis and progression of human prostate cancer. PKC-delta, -gamma, and -theta were not expressed in the epithelium of either the benign prostates or the cancers. Levels of expression for PKC-A, -iota, -mu, and RACK-1 were not significantly different between the benign and malignant groups. Although changes in PKC isoenzyme expression may assist in explaining an altered balance between proliferation and apoptosis, it is likely that changes in activity or concentrations of these isoenzymes exert important modulating influences on particular pathways regulating cellular homeostasis. The findings of this study raise an exciting possibility of novel therapeutic intervention to regulate homeostatic mechanisms controlling proliferation and/or apoptosis, including expression of the p170 drug-resistance glycoprotein, intracellular Ca2+ concentrations, and enhanced cellular mobility resulting in the metastatic dissemination of human prostate cancer cells. Attenuation of PKC-beta expression is currently being assessed as a reliable objective adjunct to morphological appearance for the diagnosis of early progressive neoplasia in human prostatic tissues.

Nerve fibres in urothelium and submucosa of neuropathic urinary bladder: an immunohistochemical study with S-100 and neurofilament

Intravesical administration of drugs has been used commonly in spinal cord injury patients to suppress detrusor hyperreflexia (eg oxybutynin, verapamil, terodiline) or, to initiate a micturition reflex (eg 15S 15-methyl prostaglandin F2 alpha, protaglandin E2); however, the response has been variable and sometimes, unpredictable. This prompted us to study the presence of nerve fibres in the vesical urothelium and submucosa in mucosal biopsies taken from the dome and trigone (obtained prior to performing a therapeutic procedure eg, vesical lithotripsy, or a diagnostic cystoscopy) in 47 consecutive, unselected paraplegic/tetraplegic patients with a neuropathic urinary bladder. Nerve fibres were demonstrated by routine immunohistochemical technique using commercially available monoclonal and polyvalent antibodies against S-100 (DAKO A/S, Glostrup, Denmark) and Neurofilament (MILAB, Malmo, Sweden). Biopsy specimens were graded for the presence of nerve fibres on a 0-3 scale for urothelium, and superficial/deep submucosa separately in a blind and randomised manner. Virtually no fibre presence was found in one paraplegic patient and no superficial or single fibres were noted in a tetraplegic patient. Absence of C-fibre hyperplasia (Grade 0) was found in nine cases (paraplegic: 4; tetraplegic: 5); Grade 1 hyperplasia was observed in 17 cases (paraplegic: 4; tetraplegic: 13); Grade 2 hyperplasia was seen in 11 cases (paraplegic: 7; tetraplegic 4); and Grade 3 hyperplasia was noticed in eight cases (paraplegic 3: tetraplegic: 5). The magnitude of C-fibre hyperplasia was not significantly different between paraplegic and tetraplegic patients (chi(2) = 4.64; P = 0.3262). The relationship, if any, between the degree of C-fibre hyperplasia and duration of paralysis was studied by categorising patients as < 5 years, and > 5 years of paralysis. No evidence of single fibre or fibre bundle hyperplasia (Grade 0) was seen in five and six cases, grade 1 hyperplasia in six and 11 cases, grade 2 hyperplasia in two and nine cases, and grade 3 hyperplasia in three and five cases respectively in these two categories of patients. (chi(2) = 1.92; P = 0.58). The possible relationship between C-fibre hyperplasia in the vesical mucosa/submucosa and (i) the vesical response to intravesical drug administration; (ii) the vesical urothelial proliferation arrest; (iii) the electrical stimulation of urinary bladder by implanted electrodes (sacral anterior root stimulator); and (iv) long-term indwelling urethral Foley catheter drainage, are discussed with illustrative case reports. In conclusion, mucosal biopsy and study of nerve fibres in urothelium and submucosa of neuropathic bladder has helped to generate hypotheses on the association between C-fibre hyperplasia and response to intravesical pharmacotherapy and the predictive value of such a study in identifying those patients who are likely to respond to intravesical pharmacotherapy.