Mammalian cells possess a multifaceted antioxidant enzyme system, which includes superoxide dismutases, catalase, the peroxiredoxin/thioredoxin and the glutathione peroxidase systems. The dichotomous role of reactive oxygen species and antioxidant enzymes in tumorigenesis and cancer progression complicates the use of small molecule antioxidants, pro-oxidants, and targeting of antioxidant enzymes as therapeutic approaches for cancer treatment. It also highlights the need for additional studies to investigate the role and regulation of these antioxidant enzymes in cancer. The focus of this review is on glutathione peroxidase 3 (GPx3), a selenoprotein, and the only extracellular GPx of a family of oxidoreductases that catalyze the detoxification of hydro- and soluble lipid hydroperoxides by reduced glutathione. In addition to summarizing the biochemical function, regulation, and disease associations of GPx3, we specifically discuss the role and regulation of systemic and tumor cell expressed GPx3 in cancer. From this it is evident that GPx3 has a dichotomous role in different tumor types, acting as both a tumor suppressor and pro-survival protein. Further studies are needed to examine how loss or gain of GPx3 specifically affects oxidant scavenging and redox signaling in the extracellular tumor microenvironment, and how GPx3 might be targeted for therapeutic intervention.

Our data demonstrate that race contributes significantly to variability of EGFR expression in prostate cancer. Racial background may have an impact on the design of clinical trials to test the efficacy of anti-EGFR agents.

Although personal melanoma risk factors are well established, the contribution of socioeconomic factors, including clothing styles, social norms, medical paradigms, perceptions of tanned skin, economic trends, and travel patterns, to melanoma incidence has not been fully explored. We analyzed artwork, advertisements, fashion trends, and data regarding leisure-time activities to estimate historical changes in UV skin exposure. We used data from national cancer registries to compare melanoma incidence rates with estimated skin exposure and found that they rose in parallel. Although firm conclusions about melanoma causation cannot be made in an analysis such as this, we provide a cross-disciplinary, historical framework in which to consider public health and educational measures that may ultimately help reverse melanoma incidence trends.

Purpose: Neutral endopeptidase (NEP) is a cell-surface peptidase that inactivates neuropeptide growth factors implicated in prostate cancer progression. The clinical significance of decreased NEP expression observed in prostate cancer is unclear. We investigated whether decreased NEP expression in localized prostate cancers is associated with prostate-specific antigen (PSA) relapse after radical prostatectomy.Experimental Design: NEP expression patterns were examined by immunohistochemistry in 223 men, who underwent radical prostatectomy between 1990 and 2000 at the Veterans Administration Medical Center (New York, NY) with available representative tissues and adequate follow up. We also examined whether hypermethylation of the NEP promoter contributes to down-regulation of NEP protein expression in a subset of patients that showed decreased NEP expression (n ‫؍‬ 22).Results: Three patterns of NEP expression were observed: (a) membranous expression similar to benign prostate epithelium (n ‫؍‬ 82; 37%); (b) complete loss of NEP expression in prostate cancer compared with adjacent benign prostate glands (n ‫؍‬ 105; 47%); and (c) heterogeneous NEP expression (n ‫؍‬ 36; 16%). In a multivariate analysis, complete loss of NEP expression was associated with PSA relapse after controlling for grade, stage, pretreatment PSA, and race simultaneously (hazard ratio, 1.99; 95% confidence interval, 1.13-3.52; two-sided 2 P ‫؍‬ 0.017). In addition, DNA hypermethylation of the NEP promoter was frequently (73%) identified in a subset of 22 of cases that showed decreased NEP expression.Conclusion: Our data suggest that decreased NEP expression might contribute to progression of localized prostate cancer after surgery. Data also suggest that methylation is an important mechanism of NEP protein silencing. Larger prospective studies are required for confirmation.

Psoriatic arthritis (PsA) is an inflammatory seronegative spondyloarthropathy associated with psoriasis. Although the main assessment measures for PsA are borrowed from the standard criteria used to assess rheumatoid arthritis, a number of new criteria such as the PsAJAI and CPDAI are being developed specifically for PsA. Long-term consequences of untreated PsA include persistent inflammation, progressive joint damage and, in many cases, substantial functional limitations, pain and disability. Moreover, patients with PsA have an increased mortality risk and an increased risk of developing cardiovascular disease and metabolic syndrome. Both GRAPPA and the AAD have developed treatment guidelines, which are discussed here. Psoriasis commonly precedes arthritic symptoms; thus, dermatologists are ideally placed to make the initial diagnosis of PsA and treat it appropriately, affording the opportunity to slow disease progression, improve physical function and enhance quality of life. This Review explores the management of patients with PsA, with a particular emphasis on assessment tools, long-term consequences and treatment issues from the viewpoint of the dermatologist.

Purpose: The protein encoded by N-myc downstreamregulated gene 1 (NDRG1) is a recently discovered protein whose transcription is induced by androgens and hypoxia. We hypothesized that NDRG1 expression patterns might reveal a biological basis for the disparity of clinical outcome of prostate cancer patients with different ethnic backgrounds.Experimental Design: Patients who underwent radical prostatectomy between 1990 and 2000 at Veterans Administration Medical Center of New York were examined. We studied 223 cases, including 157 African Americans and 66 Caucasians (T2, n ‫؍‬ 144; >T3, n ‫؍‬ 79; Gleason <7, n ‫؍‬ 122; >7, n ‫؍‬ 101). Three patterns of NDRG1 expression were identified in prostate cancer: (a) intense, predominately membranous staining similar to benign prostatic epithelium; (b) intense, nucleocytoplasmic localization; and (c) low or undetectable expression. We then examined the correlations between patients' clinicopathological parameters and different NDRG1 expression patterns.Results: In this study of patients with equal access to care, African-American ethnic origin was an independent predictor of prostate-specific antigen recurrence (P < 0.05). We also observed a significant correlation between different patterns of NDRG1 expression and ethnic origin. Pattern 2 was less frequent in African Americans (21% versus 38%), whereas the reverse was observed for pattern 3 (60% in African Americans versus 44% in Caucasians; P ‫؍‬ 0.03). This association remained significant after controlling for both grade and stage simultaneously (P ‫؍‬ 0.02).Conclusions: Our data suggest that different NDRG1 expression patterns reflect differences in the response of prostatic epithelium to hypoxia and androgens in AfricanAmerican compared with Caucasian patients. Further studies are needed to determine the contribution of NDRG1 to the disparity in clinical outcome observed between the two groups.

Our purpose was to determine the clinical relevance of the detection of circulating tumor cells (CTCs) expressing urothelial and epithelial markers in bladder cancer patients. Sixty-two patients who presented to Memorial Sloan-Kettering Cancer Center between July 2000 and September 2001 were studied. Peripheral blood was tested by nested RT-PCR assay for uroplakins (UPs) Ia, Ib, II and III as well as for epidermal growth factor receptor (EGFR). We determined the sensitivity and specificity of each individual marker and the combinations of UPIa/UPII and UPIb/UPIII. The latter strategy was based on our data, which showed that UPIa and UPIb form heterodimers with UPII and UPIII, respectively. Forty patients had clinically advanced bladder cancer and 22 had no evidence of disease at the time of assay. Eight of the 22 patients recurred during the follow-up period. All 8 patients were positive at presentation for UPIa/UPII. The combination of UPIa/UPII provided the best sensitivity (75%) of detecting CTCs, with a specificity of 50%. The combination of UPIb/UPIII was the most specific (79%) but had modest sensitivity (31%). Detection of EGFR-positive cells alone and in combination with UPs was inferior to that for UPIa/UPII. Combinations of urothelial markers are superior to single urothelial or epithelial markers in detecting CTCs in bladder cancer patients. Further efforts are under way to confirm the potential predictive value of these markers in a prospectively designed study of a larger cohort of patients.

Melanoma is the most lethal form of skin cancer and it is the second most common cancer among adolescents and young adults. The aim of this work is to determine if surgical intervals differ between four different clinics and between departments within the hospitals, and to compare these to industry standards. Surgical intervals were measured through retrospective chart review at four dermatology clinics. Of 205 melanoma cases, clinic and departmental median surgical intervals ranged 15–36.5 days and 26–48 days, respectively. There was significant association between clinic and time between biopsy and pathology report, time between pathology report and excision, and total surgical interval (P<0.0001, P=0.03, and P<0.0001 respectively). There was significant association between department and time between pathology report and excision, and surgical interval (P<0.0001, and P=0.003 respectively). Pair-wise comparisons detected significantly longer intervals between some clinics and departments (maximum difference 67.3%, P<0.0001). Hypothesis-based, informal guidelines recommend treatment within 4–6 weeks. In this study, median surgical intervals varied significantly between clinics and departments, but nearly all were within a 6-week frame.