Identification of Patients with Intermediate Thickness Melanoma at Low Risk for Sentinel Lymph Node Positivity.

INTRODUCTION: Sentinel lymph node (SLN) biopsy is recommended for all patients with intermediate-thickness melanomas. We sought to identify such patients at low risk of SLN positivity. METHODS: All patients with intermediate-thickness melanomas (1.01-4 mm) undergoing SLN biopsy at a single institution from 1995-2011 were included in this retrospective cohort study. Univariate and multivariate logistic regression determined factors associated with a low risk of SLN positivity. Classification and regression tree (CART) analysis was used to stratify groups based on risk of positivity. RESULTS: Of the 952 study patients, 157 (16.5 %) had a positive SLN. In the multivariate analysis, thickness <1.5 mm (odds ratio [OR] 0.29), age ≥60 (OR 0.69), present tumor-infiltrating lymphocytes (OR 0.60), absent lymphovascular invasion (OR 0.46), and absent satellitosis (OR 0.44) were significantly associated with a low risk of SLN positivity. CART analysis identified thickness of 1.5 mm as the primary cut point for risk of SLN metastasis. Patients with a thickness of <1.5 mm represented 36 % of the total cohort and had a SLN positivity rate of 6.6 % (95 % confidence interval 3.8-9.4 %). In patients with melanomas <1.5 mm in thickness, the presence of additional low risk factors identified 257 patients (75 % of patients with <1.5 mm melanomas) in which the rate of SLN positivity was <5 %. CONCLUSIONS: Despite a SLN positivity rate of 16.5 % overall, substantial heterogeneity of risk exists among patients with intermediate-thickness melanoma. Most patients with melanoma between 1.01 and 1.5 mm have a risk of SLN positivity similar to that in patients with thin melanomas.

The immunomodulatory effects of pegylated liposomal doxorubicin are amplified in BRCA1--deficient ovarian tumors and can be exploited to improve treatment response in a mouse model.

OBJECTIVE: Women with BRCA-associated ovarian cancer demonstrate excellent responses to Pegylated Liposomal Doxorubicin (PLD). PLD has also been shown to enhance T cell recognition of tumor cells. Here we characterize immunophenotypic changes associated with BRCA1 dysfunction in ovarian cancer cells, and evaluate the T cell contribution to the therapeutic efficacy of PLD in a BRCA1- ovarian cancer model to determine whether enhanced anti-tumor immunity contributes to the improved response to PLD in BRCA1- ovarian cancers. METHODS: The immunophenotype of BRCA1- and wild-type (WT) ovarian cancer cells and their response to PLD were compared in vitro using flow cytometry. T cell recruitment to BRCA1- tumors was evaluated with flow cytometry and immunohistochemistry. The contribution of T cell populations to the therapeutic effect of PLD in a BRCA1- model was evaluated using immunodepleting antibodies with PLD in vivo. RESULTS: The cytotoxic response to PLD was similar in BRCA1- and WT cells in vitro. BRCA1- inactivation resulted in higher expression of Fas and MHC-I at baseline and after PLD exposure. PLD prolonged the survival of BRCA1- tumor bearing mice and increased intratumoral T cell recruitment. CD4+ depletion combined with PLD significantly prolonged overall survival (p=0.0204) in BRCA1- tumor-bearing mice. CONCLUSION: Differences in the immunophenotype of BRCA1- and WT cells are amplified by PLD exposure. The enhanced immunomodulatory effects of PLD in BRCA1- tumors may be exploited therapeutically by eliminating suppressive CD4+ T cells. Our results support further study of combination therapy using PLD and immune agents, particularly in women with BRCA gene mutations.

Local immune response predicts survival in patients with thick (t4) melanomas.

BACKGROUND: Tumor infiltrating lymphocytes (TIL) and histological regression in primary melanoma are generally considered indicators of the local immune response but their roles as prognostic factors have been variably reported. We examined the prognostic role of these variables in patients with high risk (T4) primary melanomas in a large series of patients with long-term follow-up. METHODS: From a prospectively maintained cohort of patients diagnosed between 1971 and 2004, 161 patients were retrospectively identified with primary thick melanomas (>4 mm), no clinical evidence of regional nodal disease (RND) at diagnosis and complete histopathologic data. Univariate and multivariate Cox regression models were performed to identify clinical and histopathologic predictors of disease-specific survival (DSS) and to identify subgroups with differential survival. RESULTS: Factors significantly associated with decreased DSS by univariate analysis included male gender, age ≥ 60 years, axial anatomic location, presence of ulceration, RND, absence of TIL, and presence of regression. In the final multivariate model, TIL and regression, as interacting variables, and RND status remained significantly associated with DSS. In the presence of TIL, concomitant regression was associated with significantly worse survival (p ≤ 0.0001). In the absence of TIL, there was no effect of regression on survival (p = 0.324). CONCLUSIONS: Primary TIL and regression status and RND status are independently associated with melanoma-specific survival in patients with T4 melanomas; presence of TIL in the primary melanoma with concomitant radial growth phase regression is associated with a poor prognosis and may reflect an ineffective local regional immune response.

The transcriptomic responses of the eastern oyster, Crassostrea virginica, to environmental conditions.

Understanding the mechanisms by which organisms adapt to environmental conditions is a fundamental question for ecology and evolution. In this study, we evaluate changes in gene expression of a marine mollusc, the eastern oyster Crassostrea virginica, associated with the physico-chemical conditions and the levels of metals and other contaminants in their environment. The results indicate that transcript signatures can effectively disentangle the complex interactive gene expression responses to the environment and are also capable of disentangling the complex dynamic effects of environmental factors on gene expression. In this context, the mapping of environment to gene and gene to environment is reciprocal and mutually reinforcing. In general, the response of transcripts to the environment is driven by major factors known to affect oyster physiology such as temperature, pH, salinity, and dissolved oxygen, with pollutant levels playing a relatively small role, at least within the range of concentrations found in the studied oyster habitats. Further, the two environmental factors that dominate these effects (temperature and pH) interact in a dynamic and nonlinear fashion to impact gene expression. Transcriptomic data obtained in our study provide insights into the mechanisms of physiological responses to temperature and pH in oysters that are consistent with the known effects of these factors on physiological functions of ectotherms and indicate important linkages between transcriptomics and physiological outcomes. Should these linkages hold in further studies and in other organisms, they may provide a novel integrated approach for assessing the impacts of climate change, ocean acidification and anthropogenic contaminants on aquatic organisms via relatively inexpensive microarray platforms.

A transcriptomic analysis of land-use impacts on the oyster, Crassostrea virginica, in the South Atlantic bight.

Increasing utilization and human population density in the coastal zone is widely believed to place increasing stresses on the resident biota, but confirmation of this belief is somewhat lacking. While we have solid evidence that highly disturbed estuarine systems have dramatic changes in the resident biota (black and white if you will), we lack tools that distinguish the shades of grey. In part, this lack of ability to distinguish shades of grey stems from the analytical tools that have been applied to studies of estuarine systems, and perhaps more important, is the insensitivity of the biological end points that we have used to assess these impacts. In this study, we will present data on the phenotypic adjustments as measured by transcriptomic signatures of a resilient organism (oysters) to land-use practices in the surrounding watershed using advanced machine-learning algorithms. We will demonstrate that such an approach can reveal subtle and meaningful shifts in oyster gene expression in response to land use. Further, the data show that gill tissues are far more responsive and provide superior discrimination of land-use classes than hepatopancreas and that transcripts encoding proteins involved in energy production, protein synthesis and basic metabolism are more robust indicators of land use than classic biomarkers such as metallothioneins, GST and cytochrome P-450.

Revascularization strategies and in-hospital management in acute coronary syndromes complicated by hemophilia A or hemophilia B.

: Among adult patients with hemophilia A and hemophilia B the emergent management of acute coronary syndromes (ACSs) is challenging, and exposure to antithrombotic agents and/or revascularization procedures may confer an enhanced risk of bleeding. We sought to identify clinical characteristics and in-hospital outcomes among ACS patients with hemophilia A/hemophilia B, compared with matched noncoagulopathic ACS controls. Case discharges from the Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality (1998-2011) had International Classification of Diseases, 9th Revision codes for hemophilia A/hemophilia B and ACS. Control discharges were matched to cases by year of discharge and hospital. Discharges in both groups were assessed for cardiovascular risk factors, type of ACS, use of coronary artery bypass grafting, percutaneous coronary intervention (PCI), bare-metal stent and/or drug-eluting stent, bleeding, and death. In total, 237 cases and 148 848 matched controls were identified. Among cases, HIV/Hepatitis C positivity was more common and obesity/hyperlipidemia less common. ST-elevation myocardial infarction (STEMI) occurred less frequently among hemophilia A cases than controls. hemophilia A and hemophilia B cases were more likely to be managed medically. Cases treated with coronary stent placement were more likely to receive a bare-metal stent than controls. Among PCI, bleeding was more common among hemophilia A cases. The death rates were comparable between groups. ACS-hemophilia A/hemophilia B cases were more often treated noninvasively compared with controls, suggesting an avoidance of PCI/coronary artery bypass grafting in this population, and bleeding (among hemophilia A) was more common. These findings support further study of the management of ACS and in-hospital outcomes among individuals with hemophilia.

Constitutive activation of GSK3 down-regulates glycogen synthase abundance and glycogen deposition in rat skeletal muscle cells.

The effects of inhibition or constitutive activation of glycogen synthase kinase-3 (GSK3) on glycogen synthase (GS) activity, abundance, and glycogen deposition in L6 rat skeletal muscle cells were investigated. GS protein expression increased approximately 5-fold during differentiation of L6 cells (comparing cells at the end of day 5 with those at the beginning of day 3). However, exposure of undifferentiated myoblasts (day 3) to 50 microM SB-415286, a GSK3 inhibitor, led to a significant elevation in GS protein that was not accompanied by changes in the abundance of GLUT4, another late differentiation marker. In contrast, stable expression of a constitutively active form of GSK3beta (GSK3S9A) led to a significant reduction (approximately 80%) in GS protein that was antagonized by SB-415286. Inhibition of GSK3 or expression of the constitutively active GSK3S9A did not result in any detectable changes in GS mRNA abundance. However, the increase in GS protein in undifferentiated myoblasts or that seen following incubation of cells expressing GSK3S9A with GSK3 inhibitors was blocked by cycloheximide suggesting that GSK3 influences GS abundance possibly via control of mRNA translation. Consistent with the reduction in GS protein, cells expressing GSK3S9A were severely glycogen depleted as judged using a specific glycogen-staining antibody. Inhibiting GSK3 in wild-type or GSK3S9A-expressing cells using SB-415286 resulted in an attendant activation of GS, but not that of glucose transport. However, GS activation alone was insufficient for stimulating glycogen deposition. Only when muscle cells were incubated simultaneously with insulin and SB-415286 or with lithium (which stimulates GS and glucose transport) was an increase in glycogen accretion observed. Our findings suggest that GSK3 activity is an important determinant of GS protein expression and that while glycogen deposition in muscle cells is inherently dependent upon the activity/expression of GS, glucose transport is a key rate-determining step in this process.

Use of lithium and SB-415286 to explore the role of glycogen synthase kinase-3 in the regulation of glucose transport and glycogen synthase.

Glycogen synthase kinase 3 (GSK3) is inactivated by insulin and lithium and, like insulin, Li also activates glycogen synthase (GS) via inhibition of GSK3. Li also mimics insulin's ability to stimulate glucose transport (GT), an observation that has led to the suggestion that GSK3 may coordinate hormonal increases in GT and glycogen synthesis. Here we have used Li and SB-415286, a selective GSK3 inhibitor, to establish the importance of GSK3 in the hormonal activation of GT in terms of its effect on GS in L6 myotubes and 3T3-L1 adipocytes. Insulin, Li and SB-415286 all induced a significant inhibition of GSK3, which was associated with a marked dephosphorylation and activation of GS. In L6 myotubes, SB-415286 induced a much greater activation of GS (6.8-fold) compared to that elicited by insulin (4.2-fold) or Li (4-fold). In adipocytes, insulin, Li and SB-415286 all caused a comparable activation of GS despite a substantial differentiation-linked reduction in GSK3 expression ( approximately 85%) indicating that GSK3 remains an important determinant of GS activation in fat cells. Whilst Li and SB-415286 both inhibit GSK3 in muscle and fat cells, only Li stimulated GT. This increase in GT was not sensitive to inhibitors of PI3-kinase, MAP kinase or mTOR, but was suppressed by the p38 MAP kinase inhibitor, SB-203580. Consistent with this, phosphorylation of p38 MAP kinase induced by Li correlated with its stimulatory effect on GT. Our findings support a crucial role for GSK3 in the regulation of GS, but based on the differential effects of Li and SB-415286, it is unlikely that acute inhibition of GSK3 contributes towards the rapid stimulation of GT by insulin in muscle and fat cells.