Faculty Bibliography

BACKGROUND: Different Insulin-like Growth Factor Binding Proteins (IGFBPs) have been investigated as potential biomarkers in several types of tumors. In this study, we examined both IGFBP-3 and -4 levels in tissues and sera of melanoma patients representing different stages of melanoma progression. METHODS: The study cohort consisted of 132 melanoma patients (primary, n = 72; metastatic, n = 60; 64 Male, 68 Female; Median Age = 56) prospectively enrolled in the New York University School of Medicine Interdisciplinary Melanoma Cooperative Group (NYU IMCG) between August 2002 and December 2006. We assessed tumor-expression and circulating sera levels of IGFBP-3 and -4 using immunohistochemistry and ELISA assays. Correlations with clinicopathologic parameters were examined using Wilcoxon rank-sum tests and Spearman-rank correlation coefficients. RESULTS: Median IGFBP-4 tumor expression was significantly greater in primary versus metastatic patients (70% versus 10%, p = 0.01) A trend for greater median IGFBP-3 sera concentration was observed in metastatic versus primary patients (4.9 microg/ml vs. 3.4 microg/ml, respectively, p = 0.09). However, sera levels fell within a normal range for IGFBP-3. Neither IGFBP-3 nor -4 correlated with survival in this subset of patients. CONCLUSION: Decreased IGFBP-4 tumor expression might be a step in the progression from primary to metastatic melanoma. Our data lend support to a recently-described novel tumor suppressor role of secreting IGFBPs in melanoma. However, data do not support the clinical utility of measuring levels of IGFBP-3 and -4 in sera of melanoma patients

PURPOSE: Extracellular matrix remodeling during tumor growth plays an important role in angiogenesis. Our preclinical data suggest that a newly identified cryptic epitope (HU177) within collagen type IV regulates endothelial and melanoma cell adhesion in vitro and angiogenesis in vivo. In this study, we investigated the clinical relevance of HUI77 shedding in melanoma patient sera. EXPERIMENTAL DESIGN: Serum samples from 291 melanoma patients prospectively enrolled at the New York University Medical Center and 106 control subjects were analyzed for HU177 epitope concentration by a newly developed sandwich ELISA assay. HU177 serum levels were then correlated with clinical and pathologic parameters. RESULTS: Mean HU177 epitope concentration was 5.8 ng/mL (range, 0-139.8 ng/mL). A significant correlation was observed between HU177 concentration and nodular melanoma histologic subtype [nodular, 10.3 +/- 1.6 ng/mL (mean +/- SE); superficial spreading melanoma, 4.5 +/- 1.1 ng/mL; all others, 6.1 +/- 2.1 ng/mL; P = 0.01 by ANOVA test]. Increased HU177 shedding also correlated with tumor thickness (< or =1.00 mm, 3.8 +/- 1.1 ng/mL; 1.01-3.99 mm, 8.7 +/- 1.3 ng/mL; > or =4.00 mm, 10.3 +/- 2.4 ng/mL; P = 0.003 by ANOVA). After multivariate analysis controlling for thickness, the correlation between higher HU177 concentration and nodular subtype remained significant (P = 0.03). The mean HU177 epitope concentration in control subjects was 2.4 ng/mL. CONCLUSIONS: We report that primary melanoma can induce detectable changes in systemic levels of cryptic epitope shedding. Our data also support that nodular melanoma might be biologically distinct compared with superficial spreading type melanoma. As targeted interventions against cryptic collagen epitopes are currently undergoing phase I clinical trial testing, these findings indicate that patients with nodular melanoma may be more susceptible to such targeted therapies

BACKGROUND: The tumor suppressors p14(ARF) (ARF) and p16(INK4A) (p16) are encoded by overlapping reading frames at the CDKN2A/INK4A locus on chromosome 9p21. In human melanoma, the accumulated evidence has suggested that the predominant tumor suppressor at 9p21 is p16, not ARF. However, recent observations from melanoma-prone families and murine melanoma models suggest a p16-independent tumor suppressor role for ARF. We analyzed a group of melanoma metastases and cell lines to investigate directly whether somatic alterations to the ARF gene support its role as a p16-independent tumor suppressor in human melanoma, assuming that two alterations (genetic and/or epigenetic) would be required to inactivate a gene. METHODS: We examined the p16/ARF locus in 60 melanoma metastases from 58 patients and in 9 human melanoma cell lines using multiplex ligation-dependent probe amplification and multiplex polymerase chain reaction (PCR) to detect deletions, methylation-specific PCR to detect promoter methylation, direct sequencing to detect mutations affecting ARF and p16, and, in a subset of 20 tumors, immunohistochemistry to determine the effect of these alterations on p16 protein expression. All statistical tests were two-sided. RESULTS: We observed two or more alterations to the ARF gene in 26/60 (43%) metastases. The p16 gene sustained two or more alterations in 13/60 (22%) metastases (P = .03). Inactivation of ARF in the presence of wild-type p16 was seen in 18/60 (30%) metastases. CONCLUSION: Genetic and epigenetic analyses of the human 9p21 locus indicate that modifications of ARF occur independently of p16 inactivation in human melanoma and suggest that ARF is more frequently inactivated than p16

Despite the increasing use of gene transfer strategies in the study of cellular and molecular biology, melanoma cells have remained difficult to transfect in a safe, efficient, and reproducible manner. In the present study, we report the successful use of nucleofector technology to transfect human melanoma cell lines. This technology uses an empirically derived combination of cell line-specific solutions and nucleofector programmes to electroporate nucleic acid substrates directly into the cell nucleus. Using a colorimetric beta-galactosidase assay, we optimized nucleofection parameters for 13 melanoma cell lines, leading to maximum transfection efficiency and cell survival. The combinations of cell solutions NHEM or T and nucleofector programmes A-24 or U-20 produced the best results. We compared nucleofection with two commercially available lipid-based gene transfer systems, effectene and lipofectamine 2000 using a green fluorescent protein reporter vector. Nucleofection demonstrated a 3- to 40-fold improvement in transfection efficiency when compared with the lipid-based counterparts. Nucleofection was also superior in transfecting small-interfering RNA (siRNA) as determined by Western blot analysis. Lastly, we applied nucleofection to the simultaneous transfection of a p53-dependent luciferase plasmid and p53-siRNA. Experiments using dual transfection showed knockdown of p53 expression and silencing of the reporter plasmid. In conclusion, nucleofection is highly effective for the transfer of nucleic acid substrates, singly or in combination, into human melanoma cell lines

OBJECTIVE: To evaluate the performance of dermoscopists in diagnosing small pigmented skin lesions (diameter </= 6 mm) compared with an automatic multispectral computer-vision system. DESIGN: Blinded comparison study. SETTING: Dermatologic hospital-based clinics and private practice offices. Patients From a computerized skin imaging database of 990 small (</= 6-mm) pigmented skin lesions, all 49 melanomas from 49 patients were included in this study. Fifty randomly selected nonmelanomas from 46 patients served as a control. MAIN OUTCOME MEASURES: Ten dermoscopists independently examined dermoscopic images of 99 pigmented skin lesions and decided whether they identified the lesions as melanoma and whether they would recommend biopsy to rule out melanoma. Diagnostic and biopsy sensitivity and specificity were computed and then compared with the results of the computer-vision system. RESULTS: Dermoscopists were able to correctly identify small melanomas with an average diagnostic sensitivity of 39% and a specificity of 82% and recommended small melanomas for biopsy with a sensitivity of 71% and specificity of 49%, with only fair interobserver agreement (kappa = 0.31 for diagnosis and 0.34 for biopsy). In comparison, in recommending biopsy to rule out melanoma, the computer-vision system achieved 98% sensitivity and 44% specificity. CONCLUSIONS: Differentiation of small melanomas from small benign pigmented lesions challenges even expert physicians. Computer-vision systems can facilitate early detection of small melanomas and may limit the number of biopsies to rule out melanoma performed on benign lesions

OBJECTIVE: To determine the utility of the current diameter criterion of larger than 6 mm of the ABCDE acronym for the early diagnosis of cutaneous melanoma. DESIGN: Cohort study. SETTING: Dermatology hospital-based clinics and community practice offices. Patients A total of 1323 patients undergoing skin biopsies of 1657 pigmented lesions suggestive of melanoma. MAIN OUTCOME MEASURE: The maximum lesion dimension (diameter) of each skin lesion was calculated before biopsy using a novel computerized skin imaging system. RESULTS: Of 1657 biopsied lesions, 853 (51.5%) were 6 mm or smaller in diameter. Invasive melanomas were diagnosed in 13 of 853 lesions (1.5%) that were 6 mm or smaller in diameter and in 41 of 804 lesions (5.1%) that were larger than 6 mm in diameter. In situ melanomas were diagnosed in 22 of 853 lesions (2.6%) that were 6 mm or smaller in diameter and in 62 of 804 lesions (7.7%) that were larger than 6 mm in diameter. Conclusion The diameter guideline of larger than 6 mm provides a useful parameter for physicians and should continue to be used in combination with the A, B, C, and E criteria previously established in the selection of atypical lesions for skin biopsy

BACKGROUND: In patients with T1b-T3b cutaneous melanoma the utility of radiologic imaging at the time of diagnosis is unclear. Whether initial imaging led to a change in stage or treatment plan was investigated. METHODS: The melanoma database was searched for patients with T1b-T3b primary lesions, clinically N0, and asymptomatic for metastatic disease. Radiologic studies conducted before wide local excision +/- sentinel lymph node biopsy as well as all further imaging and investigations were analyzed. Outcome measures included upstaging, change in initial surgical management, true-positive, false-positive, true-negative, and false-negative rates of each imaging modality. RESULTS: In all, 344 preoperative imaging studies (chest x-ray [CXR], computed tomography [CT], positron emission tomography [PET]/CT) were performed on 158 patients, resulting in 49 findings suspicious for metastatic melanoma and 134 findings suggestive of nonmelanoma pathology. Only 1 of 344 (0.3%) studies, a PET/CT, correlated with confirmed metastatic melanoma. The false-positive rates were CXR 5 of 7 (71.4%), chest CT 21 of 24 (87.5%), abdomen/pelvis CT 10 of 11 (90.9%), head CT 2 of 2 (100.0%), PET/CT 3 of 5 (60.0%). No patient was upstaged or had a change in initial surgical management based on preoperative imaging. The cost of all initial imaging and imaging to follow-up abnormal findings was estimated as $555,308 for the 158 patients studied. CONCLUSIONS: Imaging at the time of initial diagnosis of T1b-T3b, clinically N0, M0 melanoma was of low yield with a high false-positive rate, and did not lead to upstaging or change in initial surgical management. These findings suggest that imaging of asymptomatic patients at the time of diagnosis may not be warranted