CD200 is induced by ERK and is a potential therapeutic target in melanoma.

Immune-mediated antitumor responses occur in patients with metastatic melanoma (MM), and therapies designed to augment such responses are clinically beneficial. Despite the immunogenicity of melanoma, immunomodulatory therapies fail in the majority of patients with MM. An inability of DCs to sufficiently activate effector cells may, in part, underlie this failure of the antitumor response seen in most patients. In this work, we show that mutation of N-RAS or B-RAF, signature genetic lesions present in most MMs, potently induced the expression of cell-surface CD200, a repressor of DC function. Employing 2 independent, genome-wide microarray analyses, we identified CD200 as a highly dynamic, downstream target of RAS/RAF/MEK/ERK activation in melanoma. CD200 protein was similarly overexpressed in human melanoma cell lines and primary tumors. CD200 mRNA expression correlated with progression and was higher in melanoma than in other solid tumors or acute leukemia. Melanoma cell lines expressing endogenous CD200 repressed primary T cell activation by DCs, while knockdown of CD200 by shRNA abrogated this immunosuppressive effect. These data indicate that in addition to its effects on growth, survival, and motility, ERK activation in MM attenuates a host antitumor immune response, implicating CD200 and its interaction with the CD200 receptor as a potential therapeutic target for MM.

Lack of extracellular signal-regulated kinase mitogen-activated protein kinase signaling shows a new type of melanoma.

The majority of human melanomas harbor activating mutations of either N-RAS or its downstream effector B-RAF, which cause activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase and the ERK MAPK cascade. The melanoma-relevant effectors of ERK activation, however, are largely unknown. In this work, we show that increased ERK activation correlates strongly with mutational status of N-RAS or B-RAF in 21 melanoma cell lines. Melanoma lines that were wild-type for RAS/RAF showed low levels of ERK activation comparable with primary human melanocytes. Through supervised analysis of RNA expression profiles, we identified 82 genes, including TWIST1, HIF1alpha, and IL-8, which correlated with ERK activation across the panel of cell lines and which decreased with pharmacologic inhibition of ERK activity, suggesting that they are ERK transcriptional targets in melanoma. Additionally, lines lacking mutations of N-RAS and B-RAF were molecularly distinct and characterized by p53 inactivation, reduced ERK activity, and increased expression of epithelial markers. Analysis of primary human melanomas by tissue microarray confirmed a high correlation among expression of these epithelial markers in a heterogeneous sample of 570 primary human tumors, suggesting that a significant frequency of primary melanomas is of this "epithelial-like" subtype. These results show a molecularly distinct melanoma subtype that does not require ERK activation or epithelial-mesenchymal transformation for progression.

Moderate doses of ethanol fail to increase plasma levels of neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one-like immunoreactivity in healthy men and women.

RATIONALE: The endogenous GABAergic neuroactive steroid 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP, allopregnanolone) has been proposed to contribute to ethanol actions. Humans synthesize 3alpha,5alpha-THP, but its role in response to systemic administration of ethanol is unclear. OBJECTIVE: The present study aims to determine the effect of a moderate dose of ethanol on progesterone and 3alpha,5alpha-THP concentrations in plasma samples of healthy male and female subjects and to determine if these levels are related to the subjective effects of ethanol. Females were tested in both the follicular and luteal phases of the menstrual cycle. METHODS: Healthy men (N=9) and women (N=12) aged 21-35 participated in the study. Men participated in two sessions on which they received ethanol (0.8 g/kg) or placebo. Women participated in four sessions on which they received ethanol (0.7 g/kg) or placebo during the follicular and luteal phases of their cycle. Subjective states and mood were measured by standardized self-report questionnaires and a measure of psychomotor performance. Steroid levels (progesterone, 3alpha,5alpha-THP, estradiol, and cortisol) were measured in plasma samples by radioimmunoassay. RESULTS: Ethanol significantly increased plasma levels of progesterone, but not 3alpha,5alpha-THP-like immunoreactivity, in women in the luteal phase. Ethanol had no effect on progesterone or 3alpha,5alpha-THP-like immunoreactivity levels in women in the follicular phase or in men, and it did not increase cortisol in men or women. Ethanol also did not affect estradiol in men or women. CONCLUSIONS: 3alpha,5alpha-THP-like immunoreactivity levels in human plasma are not increased following moderate ethanol consumption, suggesting that circulating levels of progesterone or its tetrahydro-reduced metabolites do not play a major role in ethanol action. However, the possibility remains that ethanol increases endogenous brain production of GABAergic neurosteroids without affecting plasma levels. Moreover, humans synthesize 5beta-reduced GABAergic steroids, and levels of these steroids may be altered in plasma or brain.

Management of unresectable stage III non-small cell lung cancer: the role of combined chemoradiation.

Until the late 1980s, thoracic radiation therapy (TRT) was considered the standard of care for patients with stage III disease despite extremely poor 5-year survival rates. Several studies evaluating TRT combined with chemotherapy showed a survival advantage. Based on these data, combined modality therapy became accepted as the standard of care in this group of patients with good performance status and made the treatment of locally advanced non-small cell lung cancer (NSCLC) a multidisciplinary endeavor. Recent studies have shown that concurrent chemoradiotherapy offers a significantly greater survival advantage than sequential chemoradiotherapy and should be considered standard of care in stage III inoperable NSCLC. Although numerous Phase III trials have clearly demonstrated a survival benefit in those patients who receive combined modality therapy, many questions remain. The most effective combination of drugs, their optimal mode of administration, the use of either induction or consolidation therapy in addition to a backbone of concurrent therapy, and the details of TRT, including total dose, fractionation, acceleration, treatment volumes, and tumor targeting remain important issues to define. Although progress has been made in treatment for locally advanced NSCLC, the majority of patients still die within 5 years either from locoregional or distant progression of disease. This article will review the current data regarding treatment of this heterogeneous group of patients. In addition, a brief summary of new molecular therapies and chemotherapeutics will be presented.

Combining anti-VEGF approaches with oxaliplatin in advanced colorectal cancer.

Angiogenesis, the formation of blood vessels, is a vital process in tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a potential target for antiangiogenic therapy because its overexpression has been associated with tumor vascularity, poor prognosis, and aggressive disease in many malignancies, including colorectal cancer (CRC). Bevacizumab is a recombinant humanized monoclonal antibody against VEGF. It is the first angiogenesis inhibitor to show significant activity in patients and, when combined with chemotherapy, leads to a significant survival benefit in CRC. This monoclonal antibody has been approved for first-line therapy in combination with intravenous 5-fluorouracil-containing regimens in patients with metastatic CRC. Vatalanib (PTK787/ZK222584) is an oral antiangiogenic tyrosine kinase inhibitor of the VEGF receptor. Currently, it is being evaluated in combination with FOLFOX (5-fluorouracil/leucovorin/oxaliplatin) in metastatic CRC. This article reviews the process of angiogenesis and the successful translation of antiangiogenic agents into the clinic. Specifically, studies evaluating VEGF-targeted agents in combination with oxaliplatin-containing regimens in CRC are discussed.

3alpha,5beta-Reduced cortisol exhibits antagonist properties on cerebral cortical GABA(A) receptors.

The tetrahydro-reduced derivatives of progesterone and deoxycorticosterone, allopregnanolone, and tetrahydrodeoxycorticosterone are potent positive modulators of GABA(A) receptors that are elevated by hypothalamic-pituitary-adrenal axis activation in rodents. In humans, 11-deoxycortisol and cortisol are important hypothalamic-pituitary-adrenal axis steroids. We hypothesized that C(3,5) reduction of 11-deoxycortisol and cortisol generates steroids with GABA(A) receptor activity. 3alpha,5beta-Reduced cortisol dose-dependently inhibited muscimol-stimulated chloride flux and tetrahydrodeoxycorticosterone potentiation of muscimol responses. Cortisol, 11-deoxycortisol, 5alpha-dihydrocortisol, 3alpha,5alpha-reduced cortisol, 3alpha,5alpha-reduced 11-deoxycortisol, and 3alpha,5beta-reduced 11-deoxycortisol had no activity at 1 muM and weaker negative modulatory activity at 10 muM. We conclude that cortisol metabolism may produce antagonistic GABAergic activity.

Current strategies in previously untreated advanced colorectal cancer.

Colorectal cancer is the second most common cause of cancer-related death in the United States. Approximately 30% to 40% of patients with colorectal cancer have locoregionally advanced or metastatic disease on presentation and cannot be cured with surgical therapy. After many years without significant change, systemic therapy for colorectal cancer is rapidly evolving. The past decade has seen the introduction of new chemotherapeutic agents such as irinotecan (Camptosar), oxaliplatin (Eloxatin) and the oral 5-FU prodrug capecitabine (Xeloda). Combination studies of these new agents with the standard 5-FU/leucovorin have extended median survival in patients with advanced colorectal cancer for up to 21 months. In addition, targeted agents with activity in colorectal cancer have emerged and are promising. This article reviews the current treatment recommendations for patients who present with advanced colorectal cancer. Survival in patients with advanced colorectal cancer is on a positive trajectory. The hope that some patients with advanced disease will be long-term survivors (even without surgery) appears to be within the range of possibility.

GABAergic neurosteroid modulation of ethanol actions.

Systemic administration of ethanol elevates plasma and cerebral cortical GABAergic neuroactive steroids. The increase in neurosteroids is responsible for specific behavioural and electrophysiological actions of ethanol in rodents. This article recapitulates the current knowledge of the novel interaction between ethanol and neurosteroids and addresses the potential mechanism for ethanol-induced increase in brain neurosteroid levels. Ethanol-induced increase in the cortical neurosteroid content is modified by neurosteroid biosynthesis inhibitors and completely prevented by adrenalectomy in male rats. In line with this, adrenalectomy prevented the anticonvulsant and hypnotic effects of acute ethanol administration. It is speculated that acute ethanol administration might resemble acute stress and increase neuroactive steroids due to activation of hypothalamic-pituitary adrenal axis. Ethanol-induced increases in neuroactive steroids might be responsible for the antidepressant, anxiolytic, spatial learning deficits and drug discriminatory actions in rodents. Thus ethanol-induced increases in neuroactive steroids represent a novel mechanism of ethanol's action, responsible for several pharmacological and behavioural actions of ethanol. The development of new therapeutic strategies for alcoholism may arise based on the novel interaction between ethanol and neurosteroids in the brain.

RNA expression analysis of formalin-fixed paraffin-embedded tumors.

RNA expression analysis is an important tool in cancer research, but a limitation has been the requirement for high-quality RNA, generally derived from frozen samples. Such tumor sets are often small and lack clinical annotation, whereas formalin-fixed paraffin-embedded (FFPE) materials are abundant. Although RT-PCR-based methods from FFPE samples are finding clinical application, genome-wide microarray analysis has proven difficult. Here, we report expression profiling on RNA from 157 FFPE tumors. RNA was extracted from 2- to 8-year-old FFPE or frozen tumors of known and unknown histologies. Total RNA was analyzed, reverse-transcribed and used for the synthesis of labeled aRNA after two rounds of amplification. Labeled aRNA was hybridized to a 3'-based 22K spot oligonucleotide arrays, and compared to a labeled reference by two-color microarray analysis. After normalization, gene expression profiles were compared by unsupervised hierarchical clustering. Using this approach, at least 24% of unselected FFPE samples produced RNA of sufficient quality for microarray analysis. From our initial studies, we determined criteria based on spectrophotometric analyses and a novel TaqMan-based assay to predict which samples were of sufficient quality for microarray analysis before hybridization. These criteria were validated on an independent set of tumors with a 100% success rate (20 of 20). Unsupervised analysis of informative gene expression profiles distinguished tumor type and subtype, and identified tumor tissue of origin in three unclassified carcinomas. Although only a minority of FFPE blocks could be analyzed, we show that informative RNA expression analysis can be derived from selected FFPE samples.