Citations

Abstract Bladder cancer is the fifth most commonly diagnosed malignancy in the United States and one of the most prevalent worldwide. It harbors a probability of recurrence of >50%; thus, rigorous, long-term surveillance of patients is advocated. Flexible cystoscopy coupled with voided urine cytology is the primary diagnostic approach, but cystoscopy is an uncomfortable, invasive procedure and the sensitivity of voided urine cytology is poor in all but high-grade tumors. Thus, improvements in noninvasive urinalysis assessment strategies would benefit patients. We applied gene expression microarray analysis to exfoliated urothelia recovered from bladder washes obtained prospectively from 46 patients with subsequently confirmed presence or absence of bladder cancer. Data from microarrays containing 56,000 targets was subjected to a panel of statistical analyses to identify bladder cancer-associated gene signatures. Hierarchical clustering and supervised learning algorithms were used to classify samples on the basis of tumor burden. A differentially expressed geneset of 319 gene probes was associated with the presence of bladder cancer (P < 0.01), and visualization of protein interaction networks revealed vascular endothelial growth factor and angiotensinogen as pivotal factors in tumor cells. Supervised machine learning and a cross-validation approach were used to build a 14-gene molecular classifier that was able to classify patients with and without bladder cancer with an overall accuracy of 76%. Our results show that it is possible to achieve the detection of bladder cancer using molecular signatures present in exfoliated tumor urothelia. Further investigation and validation of the cancer-associated profiles may reveal important biomarkers for the noninvasive detection and surveillance of bladder cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(2):444–53)

Mutation in leucine-rich repeat kinase-2 ( LRRK2 ) is the most common cause of late-onset Parkinson's disease (PD). Although most cases of PD are sporadic, some are inherited, including those caused by LRRK2 mutations. Because these mutations may be associated with a toxic gain of function, controlling the expression of LRRK2 may decrease its cytotoxicity. Here we show that the carboxyl terminus of HSP70-interacting protein (CHIP) binds, ubiquitinates, and promotes the ubiquitin proteasomal degradation of LRRK2. Overexpression of CHIP protects against and knockdown of CHIP exacerbates toxicity mediated by mutant LRRK2. Moreover, HSP90 forms a complex with LRRK2, and inhibition of HSP90 chaperone activity by 17AAG leads to proteasomal degradation of LRRK2, resulting in increased cell viability. Thus, increasing CHIP E3 ligase activity and blocking HSP90 chaperone activity can prevent the deleterious effects of LRRK2. These findings point to potential treatment options for LRRK2-associated PD.

Abstract Rationale Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea, impaired gas exchange, and ultimate mortality. Objectives To test the hypothesis that maximal oxygen uptake during cardiopulmonary exercise testing at baseline and with short-term longitudinal measures would predict mortality in patients with idiopathic pulmonary fibrosis. Methods Data from 117 patients with IPF and longitudinal cardiopulmonary exercise tests were examined retrospectively. Survival was calculated from the date of the first cardiopulmonary exercise test. Measurements and Main Results Patients with baseline maximal oxygen uptake less than 8.3 ml/kg/min had an increased risk of death (n = 8; hazard ratio, 3.24; 95% confidence interval, 1.10–9.56; P = 0.03) after adjusting for age, gender, smoking status, baseline forced vital capacity, and baseline diffusion capacity for carbon monoxide. We were unable to define a unit change in maximal oxygen uptake that predicted survival in our cohort. Conclusions We conclude that a threshold maximal oxygen uptake of 8.3 ml/kg/min during cardiopulmonary exercise testing at baseline adds prognostic information for patients with IPF.

Abstract Purpose: 17-Allylamino-17-demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic with antiproliferative activity in several mouse xenograft models, including prostate cancer models. A two-stage phase II study was conducted to assess the activity and toxicity profile of 17-AAG administered to patients with metastatic, hormone-refractory prostate cancer. Experimental Design: Patients with at least one prior systemic therapy and a rising prostate-specific antigen (PSA) were eligible. Patients received 17-AAG at a dose of 300 mg/m2 i.v. weekly for 3 of 4 weeks. The primary objective was to assess the PSA response. Secondary objectives were to determine overall survival, to assess toxicity, and to measure interleukin-6, interleukin-8, and maspin levels and quality of life. Results: Fifteen eligible patients were enrolled. The median age was 68 years and the median PSA was 261 ng/mL. Patients received 17-AAG for a median number of two cycles. Severe adverse events included grade 3 fatigue (four patients), grade 3 lymphopenia (two patients), and grade 3 back pain (two patients). The median PSA progression-free survival was 1.8 months (95% confidence interval, 1.3-3.4 months). The 6-month overall survival was 71% (95% confidence interval, 52-100%). Conclusions: 17-AAG did not show any activity with regard to PSA response. Due to insufficient PSA response, enrollment was stopped at the end of first stage per study design. The most significant severe toxicity was grade 3 fatigue. Further evaluation of 17-AAG at a dose of 300 mg/m2 i.v. weekly as a single agent in patients with metastatic, hormone-refractory prostate cancer who received at least one prior systemic therapy is not warranted.

Abstract Non-Hodgkin's lymphoma (NHL) is a cancer closely associated with immune function, and the tumor necrosis factor (TNF) G-308A promoter polymorphism, which influences immune function and regulation, was recently reported by the InterLymph Consortium to be associated with NHL risk. TNF signaling activates the nuclear factor-κB (NF-κB) canonical pathway, leading to transcriptional activation of multiple genes that influence inflammation and immune response. We hypothesized that, in addition to TNF signaling, common genetic variation in genes from the NF-κB canonical pathway may affect risk of NHL. We genotyped 54 single nucleotide polymorphisms (SNP) within TNF, lymphotoxin A LTA, and nine NF-κB genes from the canonical pathway (TNFRSF1A, TRADD, TRAF2, TRAF5, RIPK1, CHUK, IKBKB, NFKB1, and REL) in a clinic-based study of 441 incident cases and 475 frequency-matched controls. Tagging SNPs were selected from HapMap supplemented by putative functional SNPs for LTA/TNF. We used principal components and haplo.stats to model gene-level associations and logistic regression to model SNP-level associations. Compared with the wild-type (GG), the AA genotype for the TNF promoter polymorphism G-308A (rs1800629) was associated with increased risk of NHL [odds ratio (OR), 2.14; 95% confidence interval (95% CI), 0.94-4.85], whereas the GA genotype was not (OR, 1.00; 95% CI, 0.74-1.34). This association was similar for follicular lymphoma and diffuse large B-cell lymphoma. A previously reported LTA/TNF haplotype was also associated with NHL risk. In gene-level analysis of the NF-κB pathway, only NFKB1 showed a statistically significant association with NHL (P = 0.049), and one NFKB1 tagSNP (rs4648022) was associated with NHL risk overall (ordinal OR, 0.59; 95% CI, 0.41-0.84; Ptrend = 0.0037) and for each of the common subtypes. In conclusion, we provide additional evidence for the role of genetic variation in TNF and LTA SNPs and haplotypes with risk of NHL and also provide some of the first preliminary evidence for an association of genetic variation in NFKB1, a downstream target of TNF signaling, with risk of NHL. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3161–9)

Abstract Aberrant activation of the androgen receptor (AR) by the ErbB2/ErbB3 heterodimer contributes to the development of hormone resistance in prostate cancer. EBP1, an ErbB3-binding protein, acts as an AR corepressor. As EBP1 is decreased in preclinical models of hormone-refractory prostate cancer, we studied the expression of EBP1 in human prostate cancer. We found that the expression of the EBP1 gene was significantly decreased in prostate cancer tissues compared with benign prostate at both mRNA and protein levels. Restoration of EBP1 expression in the hormone-refractory LNCaP C81 cell line led to an amelioration of the androgen-independent phenotype based on established biological criteria and a reduction in the expression of a cohort of AR target genes. The ability of the ErbB3 ligand heregulin (HRG) to stimulate growth and AKT phosphorylation of hormone-refractory prostate cancer cells was abolished. Abrogation of EBP1 expression by short hairpin RNA in hormone-dependent LNCaP cells, which undergo apoptosis in response to HRG, resulted in HRG-stimulated cell growth. Restoration of EBP1 expression decreased the tumorigenicity of C81 xenografts in female mice, whereas elimination of EBP1 expression enhanced the ability of LNCaP cells to grow in female mice. Our data support a role for EBP1 in the development of hormone-refractory prostate cancer via inhibition of both AR- and HRG-stimulated growth and present a novel strategy for treating androgen-refractory prostate cancer. [Mol Cancer Ther 2008;7(10):3176–86]

The Dahl salt-sensitive rat is a widely used model of human salt-sensitive forms of hypertension. The kidney plays an important role in the pathogenesis of Dahl salt-sensitive hypertension, but the molecular mechanisms involved remain a subject of intensive investigation. Gene expression profiling studies suggested that 11β-hydroxysteroid dehydrogenase type 1 might be dysregulated in the renal medulla of Dahl salt-sensitive rats. Additional analysis confirmed that renal medullary expression of 11β-hydroxysteroid dehydrogenase type 1 was downregulated by a high-salt diet in SS-13BN rats, a consomic rat strain with reduced blood pressure salt sensitivity, but not in Dahl salt-sensitive rats. 11β-Hydroxysteroid dehydrogenase type 1 is known to convert inactive 11-dehydrocorticosterone to active corticosterone. The urinary corticosterone/11-dehydrocorticosterone ratio as well as urinary excretion of corticosterone was higher in Dahl salt-sensitive rats than in SS-13BN rats. Knockdown of renal medullary 11β-hydroxysteroid dehydrogenase type 1 with small-interfering RNA attenuated the early phase of salt-induced hypertension in Dahl salt-sensitive rats and reduced urinary excretion of corticosterone. Knockdown of 11β-hydroxysteroid dehydrogenase type 1 did not affect blood pressure in SS-13BN rats. Long-term attenuation of salt-induced hypertension was achieved with small hairpin RNA targeting renal medullary 11β-hydroxysteroid dehydrogenase type 1. In summary, we have demonstrated that suppression of 11β-hydroxysteroid dehydrogenase type 1 expression in the renal medulla attenuates salt-induced hypertension in Dahl salt-sensitive rats.