The Dietary Supplement Chondroitin-4-Sulfate Exhibits Oncogene-Specific Pro-tumor Effects on BRAF V600E Melanoma Cells.

Dietary supplements such as vitamins and minerals are widely used in the hope of improving health but may have unidentified risks and side effects. In particular, a pathogenic link between dietary supplements and specific oncogenes remains unknown. Here we report that chondroitin-4-sulfate (CHSA), a natural glycosaminoglycan approved as a dietary supplement used for osteoarthritis, selectively promotes the tumor growth potential of BRAF V600E-expressing human melanoma cells in patient- and cell line-derived xenograft mice and confers resistance to BRAF inhibitors. Mechanistically, chondroitin sulfate glucuronyltransferase (CSGlcA-T) signals through its product CHSA to enhance casein kinase 2 (CK2)-PTEN binding and consequent phosphorylation and inhibition of PTEN, which requires CHSA chains and is essential to sustain AKT activation in BRAF V600E-expressing melanoma cells. However, this CHSA-dependent PTEN inhibition is dispensable in cancer cells expressing mutant NRAS or PI3KCA, which directly activate the PI3K-AKT pathway. These results suggest that dietary supplements may exhibit oncogene-dependent pro-tumor effects.

Metabolic Rewiring by Oncogenic BRAF V600E Links Ketogenesis Pathway to BRAF-MEK1 Signaling.

Many human cancers share similar metabolic alterations, including the Warburg effect. However, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Here we demonstrate a "synthetic lethal" interaction between oncogenic BRAF V600E and a ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL). HMGCL expression is upregulated in BRAF V600E-expressing human primary melanoma and hairy cell leukemia cells. Suppression of HMGCL specifically attenuates proliferation and tumor growth potential of human melanoma cells expressing BRAF V600E. Mechanistically, active BRAF upregulates HMGCL through an octamer transcription factor Oct-1, leading to increased intracellular levels of HMGCL product, acetoacetate, which selectively enhances binding of BRAF V600E but not BRAF wild-type to MEK1 in V600E-positive cancer cells to promote activation of MEK-ERK signaling. These findings reveal a mutation-specific mechanism by which oncogenic BRAF V600E "rewires" metabolic and cell signaling networks and signals through the Oct-1-HMGCL-acetoacetate axis to selectively promote BRAF V600E-dependent tumor development.

Effect of immunotherapy time-of-day infusion on overall survival among patients with advanced melanoma in the USA (MEMOIR): a propensity score-matched analysis of a single-centre, longitudinal study.

BACKGROUND: The dependence of the adaptive immune system on circadian rhythm is an emerging field of study with potential therapeutic implications. We aimed to determine whether specific time-of-day patterns of immune checkpoint inhibitor infusions might alter melanoma treatment efficacy. METHODS: Melanoma Outcomes Following Immunotherapy (MEMOIR) is a longitudinal study of all patients with melanoma who received ipilimumab, nivolumab, or pembrolizumab, or a combination of these at a single tertiary cancer centre (Winship Cancer Institute of Emory University, Atlanta, GA, USA). For this analysis, we collected deidentified participant-level data from the MEMOIR database for adults (age ≥18 years) diagnosed with stage IV melanoma between 2012 and 2020. Those who received fewer than four infusions were excluded. Standard of care doses were used, with modifications at the treating physicians' discretion. The primary outcome was overall survival, defined as death from any cause and indexed from date of first infusion of immune checkpoint inhibitor. We calculated the association between overall survival and proportion of infusions of immune checkpoint inhibitors received after 1630 h (a composite time cutoff derived from seminal studies of the immune-circadian rhythm to represent onset of evening) using Cox regression and propensity score-matching on age, Eastern Cooperative Oncology Group performance status, serum lactate dehydrogenase concentration, and receipt of corticosteroids and radiotherapy. Treatment-related adverse events that led to change or discontinuation of immune checkpoint inhibitors were also assessed. FINDINGS: Between Jan 1, 2012, and Dec 31, 2020, 481 patients with melanoma received treatment with immune checkpoint inhibitors at the study centre, of whom 299 had stage IV disease and were included in this study; median follow-up was 27 months (IQR 14 to 47). In the complete unmatched sample, 102 (34%) patients were female and 197 (66%) were male, with a median age of 61 years (IQR 51 to 72). Every additional 20% of infusions of immune checkpoint inhibitors received after 1630 h (among all infusions received by a patient) conferred an overall survival hazard ratio (HR) of 1·31 (95% CI 1·00 to 1·71; p=0·046). A propensity score-matched analysis of patients who did (n=73) and did not (n=73) receive at least 20% of their infusions of immune checkpoint inhibitors after 1630 h (54 [37%] of 146 patients were women and 92 [63%] were men, with a median age of 58 years [IQR 48 to 68]) showed that having at least 20% of infusions in the evening was associated with shorter overall survival (median 4·8 years [95% CI 3·9 to not estimable] vs not reached; HR 2·04 [1·04 to 4·00; p=0·038]). This result remained robust to multivariable proportional hazards adjustment with (HR 1·80 [1·08 to 2·98; p=0·023]) and without (2·16 [1·10 to 4·25; p=0·025]) inclusion of the complete unmatched study sample. The most common adverse events were colitis (54 [18%] of 299 patients), hepatitis (27 [9%]), and hypophysitis (15 [5%]), and there were no treatment-related deaths. INTERPRETATION: Our findings are in line with an increasing body of evidence that adaptive immune responses are less robust when initially stimulated in the evening than if stimulated in the daytime. Although prospective studies of the timing of immune checkpoint inhibitor infusions are warranted, efforts towards scheduling infusions before mid-afternoon could be considered in the multidisciplinary management of advanced melanoma. FUNDING: National Institutes of Health, American Society for Radiation Oncology and Melanoma Research Alliance, and Winship Cancer Institute.

Combined Nivolumab and Ipilimumab in Melanoma Metastatic to the Brain.

BACKGROUND: Brain metastases are a common cause of disabling neurologic complications and death in patients with metastatic melanoma. Previous studies of nivolumab combined with ipilimumab in metastatic melanoma have excluded patients with untreated brain metastases. We evaluated the efficacy and safety of nivolumab plus ipilimumab in patients with melanoma who had untreated brain metastases. METHODS: In this open-label, multicenter, phase 2 study, patients with metastatic melanoma and at least one measurable, nonirradiated brain metastasis (tumor diameter, 0.5 to 3 cm) and no neurologic symptoms received nivolumab (1 mg per kilogram of body weight) plus ipilimumab (3 mg per kilogram) every 3 weeks for up to four doses, followed by nivolumab (3 mg per kilogram) every 2 weeks until progression or unacceptable toxic effects. The primary end point was the rate of intracranial clinical benefit, defined as the percentage of patients who had stable disease for at least 6 months, complete response, or partial response. RESULTS: Among 94 patients with a median follow-up of 14.0 months, the rate of intracranial clinical benefit was 57% (95% confidence interval [CI], 47 to 68); the rate of complete response was 26%, the rate of partial response was 30%, and the rate of stable disease for at least 6 months was 2%. The rate of extracranial clinical benefit was 56% (95% CI, 46 to 67). Treatment-related grade 3 or 4 adverse events were reported in 55% of patients, including events involving the central nervous system in 7%. One patient died from immune-related myocarditis. The safety profile of the regimen was similar to that reported in patients with melanoma who do not have brain metastases. CONCLUSIONS: Nivolumab combined with ipilimumab had clinically meaningful intracranial efficacy, concordant with extracranial activity, in patients with melanoma who had untreated brain metastases. (Funded by Bristol-Myers Squibb and the National Cancer Institute; CheckMate 204 ClinicalTrials.gov number, NCT02320058 .).

The Impact of Obesity on Surgically Treated Locoregional Melanoma.

BACKGROUND: The impact of obesity on early-stage melanoma is poorly understood. We examined the impact of overweight and obesity on clinical outcomes in locoregional melanoma. METHODS: Adults who underwent surgery at Emory University Healthcare between 2010 and 2017 for clinically stage I-II cutaneous melanoma, with known stage, height, and weight at the time of presentation, were identified. The relationship between body mass index (BMI) and clinicopathologic characteristics was assessed. RESULTS: Of 1756 patients, 584 were obese (33.2%; BMI ≥ 30), 658 were overweight (37.5%; BMI ≥ 25 and < 30), and 514 were normal weight (29.3%; BMI < 25). Demographics associated with obesity included male sex (odds ratio [OR] 2.6, 95% confidence interval [CI] 2.1-3.3; p < 0.001) and lower income (OR 1.5, 95% CI 1.2-1.9; p = 0.003). Melanomas in obese patients were thicker (2.0 ± 0.2 mm) than in overweight (1.7 ± 0.1 mm) or normal-weight patients (1.4 ± 0.1 mm; p = 0.002). Ulceration, mitoses, BRAF status, and sentinel lymph node (SLN) status were not affected by obesity. In multivariable analysis, obesity independently predicted increased odds of pathologic stage II melanoma (vs. stage 0 or I; OR 1.9, 95% CI 1.4-2.7, p = 0.001), but not pathologic stage III melanoma (p > 0.05). At 33 months' median follow-up, obesity was not an independent predictor of stage-specific overall survival (p > 0.05). CONCLUSION: Obese patients are nearly twice as likely as their normal-weight peers to present with thicker melanomas, but they have similar stage-specific overall survival and SLN positivity. Obesity may promote more aggressive growth of the primary tumor, and barriers to preventive care in obese patients may exacerbate later-stage presentation.

Recent developments in the medical and surgical treatment of melanoma.

Increasing knowledge of the biology of melanoma has led to significant advances in drug development to fight this disease. Surgery is the primary treatment for localized disease and is an integral part of management in patients with more advanced disease. The last decade has become the era of targeted therapy in melanoma and has revolutionized the treatment of this disease. Since 2011, 4 new agents have been approved for the treatment of patients with metastatic melanoma: ipilimumab, vemurafenib, dabrafenib, and trametinib. Several new agents are currently in phase 3 trials with hopes of even more agents being approved for this once "untreatable" disease. How to integrate surgical options with more effective systemic therapies has become a new challenge for physicians. This review will provide an update on current surgical options, highlight the pathway to the development of the newly approved agents, and further discuss new treatments that are on the horizon.

The evolving landscape of immunotherapy in solid tumors.

While surgical resection, local and cytotoxic therapies have long formed the basis of cancer care, immunotherapy now plays a key role in supplementing and even replacing these agents in the first line. Here we review the early success of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 blockade and discuss biomarkers of therapeutic response. We next highlight a select group of novel targets in Phase III trials both as monotherapies and in combination with PD-1 inhibitors. Finally, we discuss innovations which seek to improve outcomes in therapy-resistant solid tumors.

Adiposity may predict survival in patients with advanced stage cancer treated with immunotherapy in phase 1 clinical trials.

BACKGROUND: Body mass index (BMI) is used to define obesity, but it is an imperfect measure of body composition. In the current study, the authors explored the association between types of fat and survival in patients treated with immunotherapy. METHODS: A retrospective analysis of 90 patients who were treated with immunotherapy on phase 1 clinical trials at the Winship Cancer Institute in Atlanta, Georgia, from 2009 through 2017 was performed. Overall survival (OS) and progression-free survival (PFS) were used to measure clinical outcomes. Baseline BMI and radiographic images at the middle of the third lumbar vertebrae were obtained. Fat densities were calculated and converted to indices (subcutaneous fat index [SFI], intermuscular fat index [IFI], and visceral fat index [VFI]) after dividing by height in meters squared. Risk groups were created using recursive partitioning and the regression trees method for SFI and IFI, which were selected by stepwise variable selection among all fat-related variables. The Cox proportional hazards model and Kaplan-Meier method were used for the association with OS and PFS. RESULTS: The majority of patients (59%) were male and diagnosed with melanoma (33%) or gastrointestinal cancers (22%). The median BMI was 27.4 kg/m2 , the median SFI was 62.78, the median IFI was 4.06, and the median VFI was 40.53. Low-risk patients (those with an SFI ≥73) had a significantly longer OS (hazard ratio, 0.20; 95% CI, 0.09-0.46 [P < .001]) and PFS (hazard ratio, 0.38; 95% CI, 0.20-0.72 [P = .003]) compared with patients at intermediate risk (those with an SFI <73 and IFI <3.4) and poor risk (those with an SFI <73 and IFI ≥3.4). The Uno concordance statistics were found to be higher for fat risk groups than BMI in predicting OS (0.603 vs 0.574; P = .581) and PFS (0.602 vs 0.586; P = .71). CONCLUSIONS: Increased BMI, increased SFI, and decreased IFI may be associated with prolonged survival in patients with cancer who are treated with immunotherapy. Further studies are needed to elucidate the effect of adiposity on the host immune response to immunotherapy.

Combined Effect of Sarcopenia and Systemic Inflammation on Survival in Patients with Advanced Stage Cancer Treated with Immunotherapy.

BACKGROUND: Sarcopenia and inflammation have been associated with poor survival in patients with cancer. We explored the combined effects of these variables on survival in patients with cancer treated with immunotherapy. METHODS: We performed a retrospective review of 90 patients enrolled on immunotherapy-based phase I clinical trials at Emory University from 2009 to 2017. Baseline neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and platelet-to-lymphocyte ratio (PLR) were used as surrogates of inflammation. The skeletal muscle index (SMI) was derived from the skeletal muscle density calculated from baseline abdominal computed tomography images. Optimal cutoffs for continuous inflammation biomarkers and SMI were determined by bias-adjusted log-rank test. A four-level risk stratification was used to create low-risk (PLR <242 and nonsarcopenic), intermediate-risk (PLR <242 and sarcopenic), high-risk (PLR ≥242 and nonsarcopenic), and very-high-risk (PLR ≥242 and sarcopenic) groups with subsequent association with survival. RESULTS: Most patients (59%) were male, and the most common cancers were melanoma (33%) and gastrointestinal (22%). Very high-risk, high-risk, and intermediate-risk patients had significantly shorter overall survival (hazard ratio [HR], 8.46; 95% confidence interval [CI], 2.65-27.01; p < .001; HR, 5.32; CI, 1.96-14.43; p = .001; and HR, 4.01; CI, 1.66-9.68; p = .002, respectively) and progression-free survival (HR, 12.29; CI, 5.15-29.32; p < .001; HR, 3.51; CI, 1.37-9.02; p = .009; and HR, 2.14; CI, 1.12-4.10; p = .022, respectively) compared with low-risk patients. CONCLUSION: Baseline sarcopenia and elevated inflammatory biomarkers may have a combined effect on decreasing survival in immunotherapy-treated patients in phase I trials. These data may be immediately applicable for medical oncologists for the risk stratification of patients beginning immunotherapeutic agents. IMPLICATIONS FOR PRACTICE: Sarcopenia and inflammation have been associated with poor survival in patients with cancer, but it is unclear how to apply this information to patient care. The authors created a risk-stratification system that combined sarcopenia and platelet-to-lymphocyte ratio as a marker of systemic inflammation. The presence of sarcopenia and systemic inflammation decreased progression-free survival and overall survival in our cohort of 90 patients who received immunotherapy in phase I clinical trials. The data presented in this study may be immediately applicable for medical oncologists as a way to risk-stratify patients who are beginning treatment with immunotherapy.

Adjuvant Nivolumab versus Ipilimumab in Resected Stage III or IV Melanoma.

BACKGROUND: Nivolumab and ipilimumab are immune checkpoint inhibitors that have been approved for the treatment of advanced melanoma. In the United States, ipilimumab has also been approved as adjuvant therapy for melanoma on the basis of recurrence-free and overall survival rates that were higher than those with placebo in a phase 3 trial. We wanted to determine the efficacy of nivolumab versus ipilimumab for adjuvant therapy in patients with resected advanced melanoma. METHODS: In this randomized, double-blind, phase 3 trial, we randomly assigned 906 patients (≥15 years of age) who were undergoing complete resection of stage IIIB, IIIC, or IV melanoma to receive an intravenous infusion of either nivolumab at a dose of 3 mg per kilogram of body weight every 2 weeks (453 patients) or ipilimumab at a dose of 10 mg per kilogram every 3 weeks for four doses and then every 12 weeks (453 patients). The patients were treated for a period of up to 1 year or until disease recurrence, a report of unacceptable toxic effects, or withdrawal of consent. The primary end point was recurrence-free survival in the intention-to-treat population. RESULTS: At a minimum follow-up of 18 months, the 12-month rate of recurrence-free survival was 70.5% (95% confidence interval [CI], 66.1 to 74.5) in the nivolumab group and 60.8% (95% CI, 56.0 to 65.2) in the ipilimumab group (hazard ratio for disease recurrence or death, 0.65; 97.56% CI, 0.51 to 0.83; P<0.001). Treatment-related grade 3 or 4 adverse events were reported in 14.4% of the patients in the nivolumab group and in 45.9% of those in the ipilimumab group; treatment was discontinued because of any adverse event in 9.7% and 42.6% of the patients, respectively. Two deaths (0.4%) related to toxic effects were reported in the ipilimumab group more than 100 days after treatment. CONCLUSIONS: Among patients undergoing resection of stage IIIB, IIIC, or IV melanoma, adjuvant therapy with nivolumab resulted in significantly longer recurrence-free survival and a lower rate of grade 3 or 4 adverse events than adjuvant therapy with ipilimumab. (Funded by Bristol-Myers Squibb and Ono Pharmaceutical; CheckMate 238 ClinicalTrials.gov number, NCT02388906 ; Eudra-CT number, 2014-002351-26 .).

The prognostic and predictive impact of inflammatory biomarkers in patients who have advanced-stage cancer treated with immunotherapy.

BACKGROUND: Optimal prognostic and predictive biomarkers for patients with advanced-stage cancer patients who received immunotherapy (IO) are lacking. Inflammatory markers, such as the neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR), and the platelet-to-lymphocyte ratio (PLR), are readily available. The authors investigated the association between these markers and clinical outcomes of patients with advanced-stage cancer who received IO. METHODS: A retrospective review was conducted of 90 patients with advanced cancer who received treatment on phase 1 clinical trials of IO-based treatment regimens. NLR, MLR, and PLR values were log-transformed and treated as continuous variables for each patient. Overall survival (OS), progression-free survival (PFS), and clinical benefit were used to measure clinical outcomes. For univariate associations and multivariable analyses, Cox proportional-hazards models or logistic regression models were used. RESULTS: The median patient age was 63 years, and most were men (59%). The most common histologies were melanoma (33%) and gastrointestinal cancers (22%). High baseline NLR, MLR, and PLR values were associated significantly with worse OS and PFS (P < .05) and a lower chance of benefit (NLR and PLR; P < .05). Increased NLR, MLR, and PLR values 6 weeks after baseline were associated with shorter OS and PFS (P ≤ .052). CONCLUSIONS: Baseline and early changes in NLR, MLR, and PLR values were strongly associated with clinical outcomes in patients who received IO-based treatment regimens on phase 1 trials. Confirmation in a homogenous patient population treated on late-stage trials or outside of trial settings is warranted. These values may warrant consideration for inclusion when risk stratifying patients enrolled onto phase 1 clinical trials of IO agents.

PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma.

BACKGROUND: Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1. METHODS: In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti-PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing. RESULTS: A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients. CONCLUSIONS: In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors and those with virus-negative tumors. (Funded by the National Cancer Institute and Merck; ClinicalTrials.gov number, NCT02267603.).

Clinical outcomes of advanced stage cancer patients treated with sequential immunotherapy in phase 1 clinical trials.

Background Given the increasing number of available immunotherapeutic agents, more patients are presenting after failing immunotherapy in need of new treatment options. In this study, we investigated the clinical outcomes of patients treated with sequential immunotherapy. Methods We performed a retrospective review of 90 advanced stage cancer patients treated on immunotherapy-based phase 1 clinical trials at Winship Cancer Institute from 2009 to 2017. We included 49 patients with an immune checkpoint inhibitor (ICI)-indicated histology. Patients were analyzed based on whether they had received prior ICI. Clinical outcomes were overall survival (OS), progression-free survival (PFS), and clinical benefit (best response of complete response, partial response, or stable disease). Univariate analysis (UVA) and multivariate analysis (MVA) were performed using Cox proportional hazard or logistic regression model. Covariates included age, liver metastases, number of prior lines of therapy, histology, and Royal Marsden Hospital (RMH) risk group. Results The most common histologies were melanoma (61%) and lung/head and neck cancers (37%). More than half of patients (n = 27, 55%) received at least one ICI prior to trial enrollment: ten received anti-PD-1, two received anti-CTLA-4, five received anti-PD-1/CTLA-4 combination, and ten received multiple ICI. In MVA, ICI-naïve patients had significantly longer OS (HR: 0.22, CI: 0.07-0.70, p = 0.010) and trended towards higher chance of CB (HR: 2.52, CI: 0.49-12.97, p = 0.268). Patients who received prior ICI had substantially shorter median OS (10.9 vs 24.3 months, p = 0.046) and PFS (2.8 vs. 5.1 months, p = 0.380) than ICI-naïve patients per Kaplan-Meier estimation. Within the ICI-naïve group, 78% (7 of 9) of patients who received prior interleukin (IL-2) or interferon gamma (IFNγ) experienced disease control for at least 6 months, compared to a disease control rate of 15% (2 of 13) in patients who had received chemotherapy, targeted therapy, or no prior treatment. Conclusions ICI-naïve patients may experience improved clinical outcomes on immunotherapy-based phase 1 clinical trials than patients who have received prior ICI. This may be particularly true for patients who received prior IL-2 or IFNγ. Further development of immunotherapy combination therapies is needed to improve clinical outcomes of these patients. These results should be validated in a larger study.

HMG-CoA synthase 1 is a synthetic lethal partner of BRAFV600E in human cancers.

Contributions of metabolic changes to cancer development and maintenance have received increasing attention in recent years. Although many human cancers share similar metabolic alterations, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Using an RNAi-based screen targeting the majority of the known metabolic proteins, we recently found that oncogenic BRAFV600E up-regulates HMG-CoA lyase (HMGCL), which converts HMG-CoA to acetyl-CoA and a ketone body, acetoacetate, that selectively enhances BRAFV600E-dependent MEK1 activation in human cancer. Here, we identified HMG-CoA synthase 1 (HMGCS1), the upstream ketogenic enzyme of HMGCL, as an additional "synthetic lethal" partner of BRAFV600E Although HMGCS1 expression did not correlate with BRAFV600E mutation in human melanoma cells, HMGCS1 was selectively important for proliferation of BRAFV600E-positive melanoma and colon cancer cells but not control cells harboring active N/KRAS mutants, and stable knockdown of HMGCS1 only attenuated colony formation and tumor growth potential of BRAFV600E melanoma cells. Moreover, cytosolic HMGCS1 that co-localized with HMGCL and BRAFV600E was more important than the mitochondrial HMGCS2 isoform in BRAFV600E-expressing cancer cells in terms of acetoacetate production. Interestingly, HMGCL knockdown did not affect HMGCS1 expression levels, whereas HMGCS1 knockdown caused a compensating increase in HMGCL protein level because of attenuated protein degradation. However, this increase did not reverse the reduced ketogenesis in HMGCS1 knockdown cells. Mechanistically, HMGCS1 inhibition decreased intracellular acetoacetate levels, leading to reduced BRAFV600E-MEK1 binding and consequent MEK1 activation. We conclude that the ketogenic HMGCS1-HMGCL-acetoacetate axis may represent a promising therapeutic target for managing BRAFV600E-positive human cancers.

Balancing Inflammation: The Link between Th17 and Regulatory T Cells.

CD4(+) T cell compartments in mouse and man are composed of multiple distinct subsets each possessing unique phenotypic and functional characteristics. IL-17-producing CD4(+) T cells (Th17 cells) represent a distinct subset of the CD4(+) T cell lineage. Recent evidence suggests that Th17 cells carry out effector functions similar to cytotoxic CD8(+) T cells and play an important role in the clearance of extracellular pathogens and fungi. Th17 cell differentiation and function are closely related to the development and function of regulatory T cells (TREG). The balance between these two cell populations is essential for immune homeostasis and dysregulation of this balance has been implicated in a variety of inflammatory conditions including autoimmunity, allograft rejection, and tumorigenesis. Emerging evidence reports a significant amount of plasticity between the Th17 and regulatory T cell compartments, and the mechanisms by which these cells communicate and influence each other are just beginning to be understood. In this review, we highlight recent findings detailing the mechanisms driving Th17 and TREG plasticity and discuss the biologic consequences of their unique relationship.

Phase I study of XL281 (BMS-908662), a potent oral RAF kinase inhibitor, in patients with advanced solid tumors.

Background XL281 is a potent and selective inhibitor of wild-type and mutant RAF kinases with anti-tumor activity in multiple xenograft models. Mutations in KRAS or BRAF can activate the RAF/MEK/ERK pathway in human tumors and may confer sensitivity to RAF kinase inhibitors. Methods We performed a phase I study of XL281 in patients with advanced solid tumors. Patients were enrolled in successive cohorts of XL281 orally once daily in 28-day cycles. Twice daily dosing, different formulations, and the effect of food and famotidine were also studied. At the MTD expanded cohorts with defined mutations were treated. Results In total, 160 patients were treated. The MTD on the QD schedule was 150 mg. The most common toxicities were diarrhea, nausea, and fatigue. Plasma Cmax and AUC increased with dose. Famotidine resulted in lower AUC while food had no effect. Two patients had partial responses by RECIST: One with papillary thyroid cancer with NRAS mutation and one with uveal melanoma. Another nine patients had tumor decrease of >10% but did not meet RECIST criteria for PR. Matched tumors pairs from 33 patients showed evidence of RAF inhibition with significant decreases in pERK, pMEK and pAKT. Conclusions XL281 was generally well tolerated and the MTD was established at 150 mg/day. Partial responses and clinical benefit were observed in several patients. Tumor biopsies demonstrated effective target inhibition.

The impact of neoadjuvant hedgehog inhibitor therapy on the surgical treatment of extensive basal cell carcinoma.

BACKGROUND: Although hedgehog inhibitor therapy (HHIT) is offered as isolated medical treatment for extensive basal cell carcinoma (BCC), there is little evidence on the use of HHIT before definitive surgical intervention. In order to better define the utilization of HHIT for extensive BCC, we evaluated the impact of neoadjuvant HHIT on the subsequent surgical resection and reconstruction. METHODS: An IRB-approved, retrospective chart review was performed of patients who received HHIT as initial treatment for extensive BCC. Patients who discontinued HHIT and underwent surgical resection were included. Evaluation included BCC tumor response to HHIT, operative data, pathological data, radiation requirements, and evidence of tumor recurrence. RESULTS: Six patients were identified with tumors of the face/scalp (n = 4), trunk (n = 1) and upper extremity (n = 1). Hedgehog inhibitor therapy continued until tumors became unresponsive (n = 3, mean = 71 weeks) or side effects became intolerable (n = 3, mean = 31 weeks). In each case, a less extensive surgery was performed than estimated before HHIT. In 3 cases, significant bone resection was avoided. All resected specimens contained BCC. Four specimens exhibited clear margins. Postoperative radiation was performed in cases with positive margins (n = 2), and 1 patient experienced local recurrence. Length of follow-up was 5.7 to 11.8 months (mean = 8.23 months). CONCLUSIONS: Although HHIT was not curative for extensive BCC, HHIT can decrease the morbidity of surgical treatment and increase the likelihood of curative resection. For patients with extensive BCC, a combined neoadjuvant use of HHIT and surgical treatment should be considered.

Melanoma, version 4.2014.

The NCCN Guidelines for Melanoma provide multidisciplinary recommendations for the management of patients with melanoma. These NCCN Guidelines Insights highlight notable recent updates. Dabrafenib and trametinib, either as monotherapy (category 1) or combination therapy, have been added as systemic options for patients with unresectable metastatic melanoma harboring BRAF V600 mutations. Controversy continues regarding the value of adjuvant radiation for patients at high risk of nodal relapse. This is reflected in the category 2B designation to consider adjuvant radiation following lymphadenectomy for stage III melanoma with clinically positive nodes or recurrent disease.

BRAF mutations: signaling, epidemiology, and clinical experience in multiple malignancies.

BACKGROUND: Mutations in BRAF were first reported in 2002. Since that time, the molecular basis for oncogenic signaling has been elucidated in multiple malignancies. The development of v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors has helped improve clinical outcomes in malignant melanoma and is suggested by case reports in other malignancies. METHODS: A review of pertinent articles examining the mechanisms of BRAF signaling in various cancer types and an update on clinical trials of BRAF inhibitions are presented. RESULTS: Clinical response to BRAF inhibition varies by malignancy. In melanoma, single-agent vemurafenib or dabrafenib prolongs overall survival compared with chemotherapy, but both are limited by the development of acquired resistance in many patients. Results of early-phase clinical trials and case reports demonstrate responses in V600E-mutant non-small-cell lung cancer, thyroid cancer, and hairy cell leukemia. However, no significant difference in progression-free survival was seen in colorectal cancer with single-agent vemurafenib. Overcoming resistance to BRAF inhibition with combination therapy is an active area of research. CONCLUSIONS: The detection of BRAF mutations represents an advance in delivering molecularly targeted therapies to patients with a variety of cancers. Acquired resistance limits the ability of BRAF inhibitors to produce long-term remissions; however, combining BRAF inhibitors with the mitogen-activated protein kinase pathway and/or other pathway inhibitors represents a promising method to improve long-term outcomes.