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The transmembrane protein CLPTM1L is overexpressed in non--small cell lung cancer, where it protects tumor cells from genotoxic apoptosis. Here, we show that RNA interference-mediated blockade of CLPTM1L inhibits K-Ras--induced lung tumorigenesis. CLPTM1L expression was required in vitro for morphologic transformation by H-RasV12 or K-RasV12, anchorage-independent growth, and survival of anoikis of lung tumor cells. Mechanistic investigations indicated that CLPTM1L interacts with phosphoinositide 3-kinase and is essential for Ras-induced AKT phosphorylation. Furthermore that the anti-apoptotic protein Bcl-xL is regulated by CLPTM1L independently of AKT activation. Constitutive activation of AKT or Bcl-xL rescued the transformed phenotype in CLPTM1L-depleted cells. The CLPTM1L gene lies within a cancer susceptibility locus at chromosome 5p15.33 defined by genome-wide association studies. The risk genotype at the CLPTM1L locus was associated with high expression of CLPTM1L in normal lung tissue, suggesting that cis-regulation of CLPTM1L may contribute to lung cancer risk. Taken together, our results establish a protumorigenic role for CLPTM1L that is critical for Ras-driven lung cancers, with potential implications for therapy and chemosensitization. [ABSTRACT FROM AUTHOR]

The MAP Kinase pathway is a key signalling mechanism that regulates many cellular functions such as cell growth, transformation and apoptosis. One of the essential components of this pathway is the serine/threonine kinase, Raf. Raf (MAPKK kinase, MAPKKK) relays the extracellular signal from the receptor/Ras complex to a cascade of cytosolic kinases by phosphorylating and activating MAPK/ERK kinase (MEK; MAPK kinase, MAPKK) that phosphorylates and activates extracellular signal regulated kinase (ERK; mitogen-activated protein kinase, MAPK), which phosphorylates various cytoplasmic and nuclear proteins. Regulation of both Ras and Raf is crucial in the proper maintenance of cell growth as oncogenic mutations in these genes lead to high transforming activity. Ras is mutated in 30% of all human cancers and B-Raf is mutated in 60% of malignant melanomas. The mechanisms that regulate the small GTPase Ras as well as the downstream kinases MEK and extracellular signal regulated kinase (ERK) are well understood. However, the regulation of Raf is complex and involves the integration of other signalling pathways as well as intramolecular interactions, phosphorylation, dephosphorylation and protein–protein interactions. From studies using mammalian isoforms of Raf, as well as C. elegans lin45-Raf, common patterns and unique differences of regulation have emerged. This review will summarize recent findings on the regulation of Raf kinase. [Copyright &y& Elsevier]

Reports a study concerning the isolation of leukemia-associated Rho GEF (LARG) and PSD-95/DLG/ZO-1 homology (PDZ)-RhoGEF as plexin-B1-specific interacting proteins. Indication on the interaction between plexin-B1 and LARG; Role of LARG in plexin-B- signaling; Factors mediating Rho activation and cytoskeletal reorganization.

Presents a study which explored novel guanine nucleotide exchange factors of HRas and isolated small G-protein dissociation stimulator (GDS). Introduction to Ras family GRPases; Indentification of smgGDS as an HRasN17 binding protein; Materials and methods.

Explores the mechanisms of signal transduction of plexins-B1, a functional semaphorin receptor. Interaction with active Rac in a ligand-dependent manner; Role of Rac in mediating semaphorin signals resulting in the reorganization of actin cytoskeletal structure.

Focuses on a study which showed that the Rac1 guanosine triphosphatase can bind to and regulate signal transducers and activators of transcription (STAT) activity. How the guanine nucleotide exchange factors activate Rac; Interference of Rac1 with epidermal growth factor-stimulated Rac1; Recruitment of the STATs to cytokine receptors.

The axon guidance cue netrin is importantly involved in neuronal development. DCC (deleted in colorectal cancer) is a functional receptor for netrin and mediates axon outgrowth and the steering response. Here we show that different regions of the intracellular domain of DCC directly interacted with the tyrosine kinases Src and focal adhesion kinase (FAK). Netrin activated both FAK and Src and stimulated tyrosine phosphorylation of DCC. Inhibition of Src family kinases reduced DCC tyrosine phosphorylation and blocked both axon attraction and outgrowth of neurons in response to netrin. Mutation of the tyrosine phosphorylation residue in DCC abolished its function of mediating netrin-induced axon attraction. On the basis of our observations, we suggest a model in which DCC functions as a kinase-coupled receptor, and FAK and Src act immediately downstream of DCC in netrin signaling. [ABSTRACT FROM AUTHOR]

Although the ras genes have long been established as proto-oncogenes, the dominant role of activated ras in cell transformation has been questioned. Previous studies have shown frequent loss of the wildtype Kras2 allele in both mouse and human lung adenocarcinomas. To address the possible tumor suppressor role of wildtype Kras2 in lung tumorigenesis, we have carried out a lung tumor bioassay in heterozygous Kras2-deficient mice. Mice with a heterozygous Kras2 deficiency were highly susceptible to the chemical induction of lung tumors when compared to wildtype mice. Activating Kras2 mutations were detected in all chemically induced lung tumors obtained from both wildtype and heterozygous Kras2-deficient mice. Furthermore, wildtype Kras2 inhibited colony formation and tumor development by transformed NIH/3T3 cells and a mouse lung tumor cell line containing an activated Kras2 allele. Allelic loss of wildtype Kras2 was found in 67% to 100% of chemically induced mouse lung adenocarcinomas that harbor a mutant Kras2 allele. Finally, an inverse correlation between the level of wildtype Kras2 expression and extracellular signal-regulated kinase (ERK) activity was observed in these cells. These data strongly suggest that wildtype Kras2 has tumor suppressor activity and is frequently lost during lung tumor progression. [ABSTRACT FROM AUTHOR]

Objectives: The treatment paradigm in newly diagnosed multiple myeloma (NDMM) is evolving toward individualized, risk‐directed, and longer duration of therapy (DOT). The objective of this study was to describe treatment patterns and outcomes in non‐transplant NDMM in four European countries. Methods: This retrospective chart review included adults with NDMM diagnosed between January 1, 2012, and December 31, 2013 (early cohort), or April 1, 2016, and March 31, 2017 (recent cohort). Results: Among 836 patients, molecular testing was performed in 21% and 35% patients of early vs recent cohorts; proteasome inhibitor (PI)/alkylator combinations were the principal first‐line (1 L) therapy (39% vs 43%). Use of immunomodulatory drug (IMID)/alkylator combinations declined from early to recent cohort (26% vs 13%) but IMID (7% vs 16%) use increased. Few patients (5%) received 1 L maintenance therapy. Two‐thirds of patients were treated with a fixed duration intent, with a median 7‐month 1 L DOT and progression‐free survival (PFS) of 32.8 months in the early cohort. Both 1 L DOT and PFS were longer with oral compared to injectable regimens. Conclusions: Although frontline treatment patterns changed significantly, 1 L DOT is short. The uptake of molecular testing and 1 L maintenance is low. These results highlight areas of unmet need in NDMM. [ABSTRACT FROM AUTHOR]

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting. [ABSTRACT FROM AUTHOR]

Non--small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide and results from a complex interaction between carcinogen exposure and inherent susceptibility. Despite its prevalence, genetic factors that predispose to the development of lung cancer remain elusive. Inbred mouse models offer a unique and clinically relevant tool to study genetic factors that contribute to lung carcinogenesis due to the development of tumors that resemble human adenocarcinoma and broad strain-specific variation in cancer incidence after carcinogen administration. Here, we set out to investigate whether strain-specific variability in tumor immunosurveillance contributes to differences in lung cancer. Using bone marrow transplantation, we determined that hematopoietic cells from lung cancer--resistant mice could significantly impede the development of cancer in a susceptible strain. Furthermore, we show that this is not due to differences in tumor-promoting inflammatory changes or variability in immunosurveillance by the adaptive immune system but results from strain-specific differences in natural killer (NK) cell cytotoxicity. Using a newly discovered congenic strain of mice, we show a previously unrecognized role for strain-specific polymorphisms in the natural killer gene complex (NKC) in immunosurveillance for carcinogen-induced lung cancer. Because polymorphisms in the NKC are highly prevalent in man, our data may explain why certain individuals without obvious risk factors develop lung cancer whereas others remain resistant to the disease despite heavy environmental carcinogen exposure. [ABSTRACT FROM AUTHOR]

In this article, the authors discuss the principles on genome wide association studies (GWAS) on the functional characterization of cancer risk loci. The authors suggest a systematic strategy for understanding the mechanism of cancer-associated variants as well as common genetic or epigenetic variation. The authors highlight appropriate models and assays to test the functional effects of genes mapping and single nucleotide polymorphisms (SNPs) to cancer predisposition loci.