Faculty Bibliography

Background: Cell surface glycans, oligosaccharides present on proteins and lipids, play important roles in a range of biological processes. Our group recently reported on the role of aberrant glycosylation in promoting melanoma cell invasion and immunosuppression (Cancer Cell, 2011). In this study, we further exploit the ability of glycomic profiling of melanoma, using lectin microarrays, to identify differences in melanoma-associated glycosylation for new melanoma biomarkers and/or targets of treatment. Methods: We utilized a ratiometric dual colored 90-lectin microarray to examine differences in glycosylation between 13 primary and 14 metastatic melanoma cell lines, 5 human melanoma tissues and 4 human epidermal melanocytes (HEM). One HEM was used as a biological reference for hybridization. A subset of melanoma cell lines (n=4) was used for comparison with the glycomic profiles of the NCI-60 lines using a mixed reference. Hierarchical clustering of lectins with significant differences in binding to the sample sets (t-tests, p<0.05) was used to visualize and infer differences in glycosylation patterns. Results: A shift in the glycome related to reduction in expression of high mannose and core fucosylated complex N-glycans was seen in melanoma cell lines and tissues compared to HEMs. Glycomic profiles of primary and metastatic melanoma were similar. Interestingly, enrichment of high mannose and potentially a-2,3 sialic acid was seen in BRAF mutant (n=19) compared to BRAF wild type (n=8) cell lines. Our tested melanoma cell lines showed similar glycosylation patterns compared to melanoma lines of the NCI-60 panel, which all show higher expression of high mannose and complex N-glycans compared to other cancers. Comparison of melanoma cell lines to tissues shows similar glycomic profiles, suggesting that glycosylation of melanoma cells is not significantly altered (or blunted) due to culture. Conclusions: Our data suggest that alterations in cell surface glycosylation may be an early event in the!

ABSTRACT: BACKGROUND: Identification of melanoma patients at high risk for recurrence and monitoring for recurrence are critical for informed management decisions. We hypothesized that serum microRNAs (miRNAs) could provide prognostic information at the time of diagnosis unaccounted for by the current staging system and could be useful in detecting recurrence after resection. METHODS: We screened 355 miRNAs in sera from 80 melanoma patients at primary diagnosis (discovery cohort) using a unique quantitative reverse transcription-PCR (qRT-PCR) panel. Cox proportional hazard models and Kaplan-Meier recurrence-free survival (RFS) curves were used to identify a miRNA signature with prognostic potential adjusting for stage. We then tested the miRNA signature in an independent cohort of 50 primary melanoma patients (validation cohort). Logistic regression analysis was performed to determine if the miRNA signature can determine risk of recurrence in both cohorts. Selected miRNAs were measured longitudinally in subsets of patients pre-/post-operatively and pre-/post-recurrence. RESULTS: A signature of 5 miRNAs successfully classified melanoma patients into high and low recurrence risk groups with significant separation of RFS in both discovery and validation cohorts (p = 0.0036, p = 0.0093, respectively). Significant separation of RFS was maintained when a logistic model containing the same signature set was used to predict recurrence risk in both discovery and validation cohorts (p < 0.0001, p = 0.033, respectively). Longitudinal expression of 4 miRNAs in a subset of patients was dynamic, suggesting miRNAs can be associated with tumor burden. CONCLUSION: Our data demonstrate that serum miRNAs can improve accuracy in identifying primary melanoma patients with high recurrence risk and in monitoring melanoma tumor burden over time.

The sentinel lymph node is the initial site of metastasis. Downregulation of antitumor immunity has a role in nodal progression. Our objective was to investigate the relationship between immune modulation and sentinel lymph node positivity, correlating it with outcome in melanoma patients. Lymph node/primary tissues from melanoma patients prospectively accrued and followed at New York University Medical Center were evaluated for the presence of regulatory T cells (Foxp3(+)) and dendritic cells (conventional: CD11c(+), mature: CD86(+)) using immunohistochemistry. Primary melanoma immune cell profiles from sentinel lymph node-positive/-negative patients were compared. Logistic regression models inclusive of standard-of-care/immunological primary tumor characteristics were constructed to predict the risk of sentinel lymph node positivity. Immunological responses in the positive sentinel lymph node were also compared with those in the negative non-sentinel node from the same nodal basin and matched negative sentinel lymph node. Decreased immune response was defined as increased regulatory T cells or decreased dendritic cells. Associations between the expression of these immune modulators, clinicopathological variables, and clinical outcome were evaluated using univariate/multivariate analyses. Primary tumor conventional dendritic cells and regression were protective against sentinel lymph node metastasis (odds ratio=0.714, 0.067; P=0.0099, 0.0816, respectively). Antitumor immunity was downregulated in the positive sentinel lymph node with an increase in regulatory T cells compared with the negative non-sentinel node from the same nodal basin (P=0.0005) and matched negative sentinel lymph node (P=0.0002). The positive sentinel lymph node also had decreased numbers of conventional dendritic cells compared with the negative sentinel lymph node (P<0.0001). Adding sentinel lymph node regulatory T cell expression improved the discriminative power of a recurrence risk assessment model using clinical stage. Primary tumor regression was associated with prolonged disease-free (P=0.025) and melanoma-specific (P=0.014) survival. Our results support an assessment of local immune profiles in both the primary tumor and sentinel lymph node to help guide therapeutic decisions.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) is a proven method for weight reduction. Less is known about pregnancies in patients after LAGB. METHODS: Information was gathered, through database and survey, on women who underwent LAGB at NYU Medical Center between 2001 and 2008 then became pregnant. RESULTS: Pregnancy occurred in 133 women, resulting in 112 babies, including six sets of twins. The average pre-pregnancy body mass index (BMI) was 32.7. Average weight gain was 11.5 kg, but was higher for those with pre-pregnancy BMI <30.0 compared to BMI >30.0 (16.4 vs 8.6 kg). Of singleton pregnancies, 89% were carried to full term, with cesarean section in 45%. Those with pre-pregnancy BMI <30.0 had a lower rate of cesarean section (35.71%), but it was not statistically significant (p = 0.55). Average birth weight was 3,268.6 g. Eight percent of babies from singleton pregnancies were low birth weight (<2,500 g), and seven percent were high birth weight (>4,000 g). Average Apgar scores at 1 and 5 min were 8.89 and 9.17. Four percent of patients developed gestational diabetes, and 5% developed pre-eclampsia. Band adjustments were performed in 71% of patients. Weight gain was higher in those who had their bands loosened in the first trimester (p = 0.063). Three patients had intrapartum band slips; one required surgery during pregnancy. CONCLUSIONS: LAGB is tolerable in pregnancy with rare intrapartum band slips. Weight gain is less in those with higher pre-pregnancy BMI and those who had their bands filled or not adjusted. Babies born to these mothers are as healthy as the general population

Reconstruction of the abdominal wall to repair ventral hernias continues to pose a challenge to surgeons due to relatively high rates of recurrence and morbidity. In 1990, Ramirez pioneered a technique of components separation of the abdominal wall for ventral hernia repair. Although an effective hernia repair, the mobilization of skin and subcutaneous tissue endangers the blood supply and predisposes midline skin to necrosis. The goal of this study is to determine whether releasing incisions in the transversus abdominis fascia and posterior rectus sheath provide adequate mobilization of the abdominal wall necessary for ventral hernia repair, thus paving the way for a laparoscopic component separation technique. Ten fresh cadavers were used and one side of the abdomen underwent the conventional Ramirez components separation: midline incision, dissection of skin and subcutaneous tissue off the anterior abdominal wall, and incisions in the external oblique aponeurosis and posterior rectus sheath, while the other side received incisions in the transversus abdominis fascia and the posterior rectus sheath with no undermining of the skin. The amount of fascial translation was measured after each incision. Incising only the external oblique aponeurosis produced greater mobilization of the abdominal wall at the level of the umbilicus (P = 0.02) and anterior superior iliac spine (ASIS, P = 0.029) than releasing only transversus abdominis fascia. More importantly, there was no statistically significant difference in the amount of release produced by the complete internal-release components separation versus the conventional technique. In order to test the feasibility of performing the procedure laparoscopically, one additional cadaver underwent a laparoscopic transversus abdominis fascia release. The procedure was successful and resulted in comparable amounts of fascial release as the other 10 cadavers. From this study, it appears technically feasible to perform a laparoscopic components separation to repair a ventral hernia and the procedure produces the same amount of release as the conventional open component separation technique.