Faculty Bibliography

While the role of genetic risk factors in the etiology of uveal melanoma (UM) has been strongly suggested, the genetic susceptibility to UM is currently vastly unexplored. Due to shared epidemiological risk factors between cutaneous melanoma (CM) and UM, in this study we have selected 28 SNPs identified as risk variants in previous genome-wide association studies on CM or CM-related host phenotypes (such as pigmentation and eye color) and tested them for association with UM risk. By logistic regression analysis of 272 UM cases and 1782 controls using an additive model, we identified five variants significantly associated with UM risk, all passing adjustment for multiple testing. The three most significantly associated variants rs12913832 (OR = 0.529, 95% CI 0.415-0.673; p = 8.47E-08), rs1129038 (OR = 0.533, 95% CI 0.419-0.678; p = 1.19E-07) and rs916977 (OR = 0.465, 95% CI 0.339-0.637; p = 3.04E-07) are correlated (r(2) > 0.5) and map at 15q12 in the region of HERC2/OCA2, which determines eye-color in the human population. Our data provides first evidence that the genetic factors associated with pigmentation traits are risk loci of UM susceptibility.

Tumor infiltrating lymphocytes (TILs) in primary melanomas are thought to represent the host anti-tumor immune response, but controversy exists over whether TILs offer independent prognostication of survival. We studied a cohort of 1241 primary melanoma patients to assess the association of absent, non-brisk, and brisk TIL grade with survival outcomes. We tested whether quantitative TIL counts using immunohistochemical lymphocyte markers CD3, CD45, and FOXP3 add prognostic value to TIL grading compared to histology alone in 15% of the cohort. To assess for inter-group immunologic heterogeneity among TIL grades, we investigated differential expression of 594 immunoregulatory genes in 67 primary melanomas. On histologic evaluation of 1241 primary melanomas, TILs were graded as absent (n=388, 31%), non-brisk (n=330, 27%), and brisk (n=523, 42%). Patients with brisk TILs had improved recurrence-free survival (RFS) (P=.025) and overall survival (OS) (P=.006) compared to patients with non-brisk and absent TILs, for which there were no differences in RFS (P=.40) or OS (P=.41). TIL quantitation by immunohistochemistry did not improve prognostication compared to TIL grading on hematoxylin and eosin stained sections. Melanomas with non-brisk and absent TILs share similar immunoregulatory gene expression profiles. In contrast, melanomas with brisk TILs demonstrate upregulation of T-cell activation pathways and inhibition of upstream immune checkpoint regulators. The presence of TILs in primary melanomas represents a heterogeneous group and caution in prognostic interpretation is warranted. Melanomas with brisk TILs are defined by an immunostimulatory gene expression profile and improved prognosis compared to melanomas with non-brisk or absent TILs.

Despite significant advances in melanoma therapy, melanoma remains the deadliest form of skin cancer, with a 5-year survival rate of only 15%. Thus, novel treatments are required to address this disease. Notch and ERBB are evolutionarily conserved signaling cascades required for the maintenance of melanocyte precursors. We show that active Notch1 (Notch1(NIC)) and active (phosphorylated) ERBB3 and ERBB2 correlate significantly and are similarly expressed in both mutated and wild-type BRAF melanomas, suggesting these receptors are co-reactivated in melanoma to promote survival. Whereas blocking either pathway triggers modest effects, combining a ?-secretase inhibitor to block Notch activation and a tyrosine kinase inhibitor to inhibit ERBB3/2 elicits synergistic effects, reducing cell viability by 90% and hampering melanoma tumor growth. Specific inhibition of Notch1 and ERBB3 mimics these results, suggesting these are the critical factors triggering melanoma tumor expansion. Notch and ERBB inhibition blunts AKT and NF?B signaling. Constitutive expression of NF?B partially rescues cell death. Blockade of both Notch and ERBB signaling inhibits the slow cycling JARID1B-positive cell population, which is critical for long-term maintenance of melanoma growth. We propose that blocking these pathways is an effective approach to treatment of melanoma patients regardless of whether they carry mutated or wild-type BRAF.

CD8+ T cells develop increased sensitivity following Ag experience, and differences in sensitivity exist between T cell memory subsets. How differential TCR signaling between memory subsets contributes to sensitivity differences is unclear. We show in mouse effector memory T cells (TEM) that >50% of lymphocyte-specific protein tyrosine kinase (Lck) exists in a constitutively active conformation, compared with <20% in central memory T cells (TCM). Immediately proximal to Lck signaling, we observed enhanced Zap-70 phosphorylation in TEM following TCR ligation compared with TCM Furthermore, we observed superior cytotoxic effector function in TEM compared with TCM, and we provide evidence that this results from a lower probability of TCM reaching threshold signaling owing to the decreased magnitude of TCR-proximal signaling. We provide evidence that the differences in Lck constitutive activity between CD8+ TCM and TEM are due to differential regulation by SH2 domain-containing phosphatase-1 (Shp-1) and C-terminal Src kinase, and we use modeling of early TCR signaling to reveal the significance of these differences. We show that inhibition of Shp-1 results in increased constitutive Lck activity in TCM to levels similar to TEM, as well as increased cytotoxic effector function in TCM Collectively, this work demonstrates a role for constitutive Lck activity in controlling Ag sensitivity, and it suggests that differential activities of TCR-proximal signaling components may contribute to establishing the divergent effector properties of TCM and TEM. This work also identifies Shp-1 as a potential target to improve the cytotoxic effector functions of TCM for adoptive cell therapy applications.

BACKGROUND: Although 20% to 30% of melanomas are histopathologically 'nevus associated,' the majority of melanomas arise de novo, ie, in clinically normal skin with no associated nevus. We examined whether these forms of melanoma differed in their associations with clinical and histopathologic features and patient survival. METHODS: We analyzed two prospective cohorts from our institution with protocol-driven follow-up information (NYU1, n = 1024; NYU2, n = 1125). We used univariate and multivariable analyses to examine associations between de novo vs nevus-associated melanoma classification and age, anatomic site, tumor thickness, tumor ulceration, mitotic index, histological subtype, clinical stage, and survival. We tested the associations identified in NYU1 using NYU2 as a replication cohort. All tests of statistical significance were two-sided. RESULTS: In NYU1, de novo melanomas were associated with tumor thickness greater than 1.0 mm (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.43 to 2.70, P < .001), ulceration (OR = 1.65, 95% CI = 1.10 to 2.54, P = .02), nodular subtype (OR = 3.26, 95% CI = 1.70 to 7.11, P = .001), greater than stage I (OR = 2.35, 95% CI = 1.65 to 3.40, P < .001), older age (OR = 1.64, 95% CI = 1.18 to 2.30, P = .004), and shorter overall survival (HR = 1.63, 95% CI = 1.22 to 2.18, P < .001). In NYU2, de novo melanoma was again statistically significantly associated with thickness greater than 1.0 mm (OR = 2.24, 95% CI = 1.72 to 2.93, P < .001), ulceration (OR = 2.88, 95% CI = 1.95 to 4.37, P < .001), nodular subtype (OR = 2.41, 95% CI = 1.75 to 3.37, P < .001), greater than stage I (OR = 2.42, 95% CI = 1.80 to 3.29, P < .001), older age (OR = 1.68, 95% CI = 1.31 to 2.17, P < .001), and shorter overall survival (HR = 2.52, 95% CI = 1.78 to 3.56, P < .001). In multivariable analysis, de novo classification was an independent, poor prognostic indicator in NYU2 (HR = 1.70, 95% CI = 1.19 to 2.44, P = .004). Male patients had a statistically significantly worse survival than female patients if their melanoma was de novo (NYU1, P < .001; NYU2, P < .001); unexpectedly, there was no sex difference in survival among patients with nevus-associated tumors. CONCLUSIONS: These data suggest that de novo melanomas are more aggressive than nevus-associated melanomas. This classification scheme may also provide a useful framework for investigations into sex differences in melanoma outcomes.

Despite major advances in the treatment of metastatic melanoma, treatment failure is still inevitable in most cases. Manipulation of key epigenetic regulators, including inhibition of Bromodomain and extra-terminal domain (BET) family members impairs cell proliferation in vitro and tumor growth in vivo in different cancers, including melanoma. Here, we investigated the effect of combining the BET inhibitor JQ1 with the BRAF inhibitor Vemurafenib in in vitro and in vivo models of BRAF-mutant melanoma. We performed cytotoxicity and apoptosis assays, and a xenograft mouse model to determine the in vitro and in vivo efficacy of JQ1 in combination with Vemurafenib against BRAF-mutant melanoma cell lines. Further, to investigate the molecular mechanisms underlying the effects of combined treatment, we conducted antibody arrays of in vitro drug-treated cell lines and RNA sequencing of drug-treated xenograft tumors. The combination of JQ1 and Vemurafenib acted synergistically in BRAF-mutant cell lines, resulting in marked apoptosis in vitro, with upregulation of proapoptotic proteins. In vivo, combination treatment suppressed tumor growth and significantly improved survival compared to either drug alone. RNA sequencing of tumor tissues revealed almost four thousand genes that were uniquely modulated by the combination, with several anti-apoptotic genes significantly down-regulated. Collectively, our data provide a rationale for combined BET and BRAF inhibition as a novel strategy for the treatment of melanoma.

Exosomes are produced by cells to mediate intercellular communication, and have been shown to perpetuate diseases, including cancer. New tools are needed to understand exosome biology, detect exosomes from specific cell types in complex biological media, and to modify exosomes. Our data demonstrate a cellular pathway whereby membrane-bound scavenger receptor type B-1 (SR-B1) in parent cells becomes incorporated into exosomes. We tailored synthetic HDL-like nanoparticles (HDL NP), high-affinity ligands for SR-B1, to carry a fluorescently labeled phospholipid. Data show SR-B1-dependent transfer of the fluorescent phospholipid from HDL NPs to exosomes. Modified exosomes are stable in serum and can be directly detected using flow cytometry. As proof-of-concept, human serum exosomes were found to express SR-B1, and HDL NPs can be used to label and isolate them. Ultimately, we discovered a natural cellular pathway and nanoparticle-receptor pair that enables exosome modulation, detection, and isolation.

OBJECTIVES: The impact of ethnicity and the socioeconomic status (SES) among Caucasians is not well studied. Here, we examine the impact of income on melanoma presentation and prognosis within a Caucasian cohort, accounting for ethnicity, as some reports suggest increased melanoma incidence in Ashkenazi Jewish (AJ) BRCA mutation carriers. METHODS: We studied prospectively enrolled primary melanoma patients at New York University. SES data were estimated using United States' Census Bureau data and patient zip codes. We evaluated associations between ethnicity, SES, and baseline characteristics using the x03C7;2 test and multivariate logistic regression. We compared survival distributions using Kaplan-Meier curves, log-rank tests, and Cox proportional hazard ratios. RESULTS: Of the 1,339 enrolled patients, AJ represented 32% (n = 423). Apart from AJ being older at presentation (p < 0.001), no significant differences were observed in baseline characteristics between ethnic groups. Patients with a median household income (MHI) lower than the median of the cohort were significantly more likely to present with advanced stages (p < 0.001) compared to patients with a higher MHI. Shorter overall (p = 0.016) and post-recurrence survival (p = 0.042) was also observed in patients from lower-income households. CONCLUSION: Data suggest that disparities in melanoma presentation in Caucasians stratify according to income independent of ethnic background.

Endothelin-1 (ET-1) is a vasoactive peptide that also plays a role in the tanning response of the skin. Animal and cell culture studies have also implicated ET-1 in melanoma progression, but no association studies have been performed to link ET-1 expression and melanoma in humans. Here, we present the first in-vivo study of ET-1 expression in pigmented lesions in humans: an ET-1 immunohistochemical screen of melanocytic nevi, melanoma in situ lesions, invasive melanomas, metastatic melanomas, and blue nevi was performed. Twenty-six percent of melanocytic nevi and 44% of melanoma in situ lesions demonstrate ET-1 expression in the perilesional microenvironment, whereas expression in nevus or melanoma cells was rare to absent. In striking contrast, 100% of moderately to highly pigmented invasive melanomas contained numerous ET-1-positive cells in the tumor microenvironment, with 79% containing ET-1-positive melanoma cells, confirmed by co-staining with melanoma tumor marker HMB45. Hypopigmented invasive melanomas had reduced ET-1 expression, suggesting a correlation between ET-1 expression and pigmented melanomas. ET-1-positive perilesional cells were CD68-positive, indicating macrophage origin. Sixty-two percent of highly pigmented metastatic melanomas demonstrated ET-1 expression in melanoma cells, in contrast to 28.2% of hypopigmented specimens. Eighty-nine percent of benign nevi, known as blue nevi, which have a dermal localization, were associated with numerous ET-1-positive macrophages in the perilesional microenvironment, but no ET-1 expression was detected in the melanocytes. We conclude that ET-1 expression in the microenvironment increases with advancing stages of melanocyte transformation, implicating a critical role for ET-1 in melanoma progression, and the importance of the tumor microenvironment in the melanoma phenotype.