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Anticancer therapies have been limited by the emergence of mutations and other adaptations. In bacteria, antibiotics activate the SOS response, which mobilizes error-prone factors that allow for continuous replication at the cost of mutagenesis. We investigated whether the treatment of lung cancer with EGFR inhibitors (EGFRi) similarly engages hypermutators. In cycling drug-tolerant persister (DTP) cells and in EGFRi-treated patients presenting residual disease, we observed upregulation of GAS6, whereas ablation of GAS6's receptor, AXL, eradicated resistance. Reciprocally, AXL overexpression enhanced DTP survival and accelerated the emergence of T790M, an EGFR mutation typical to resistant cells. Mechanistically, AXL induces low-fidelity DNA polymerases and activates their organizer, RAD18, by promoting neddylation. Metabolomics uncovered another hypermutator, AXL-driven activation of MYC, and increased purine synthesis that is unbalanced by pyrimidines. Aligning anti-AXL combination treatments with the transition from DTPs to resistant cells cured patient-derived xenografts. Hence, similar to bacteria, tumors tolerate therapy by engaging pharmacologically targetable endogenous mutators. Significance: EGFR-mutant lung cancers treated with kinase inhibitors often evolve resistance due to secondary mutations. We report that in similarity to the bacterial SOS response stimulated by antibiotics, endogenous mutators are activated in drug-treated cells, and this heralds tolerance. Blocking the process prevented resistance in xenograft models, which offers new treatment strategies. This article is highlighted in the In This Issue feature, p. 2483

ShcA is a protein that is recruited to receptor-protein tyrosine kinases, where it is phosphorylated on several tyrosine residues. These phosphotyrosine residues act as binding sites for Grb2. Interestingly, some receptors also bind Grb2 directly, which would suggest a redundant role for ShcA. Recently, we demonstrated that cells expressing receptors engineered to bind ShcA display enhanced rates of cell division compared to cells expressing versions of the receptor designed to bind Grb2 directly. In this dissertation, I describe our efforts to identify and characterize novel ShcA-binding proteins that may play a role in this phenomenon.Chapter 1 is an introductory chapter that describes the field of receptor protein-tyrosine kinase signaling.Chapter 2 describes the use of ShcA-derived phosphopeptides as reagents to purify proteins that bind ShcA in a phosphorylation-dependent manner. This led to the identification of STS-1 as a protein that associates with the phosphorylated Tyr317 region of ShcA. In cell-based experiments, we demonstrate that the association between STS-1 and ShcA is enhanced following growth factor stimulation.In chapter 3, we demonstrate that STS-1 binds directly to the phosphorylated Tyr317 ShcA-derived peptide. To determine which region of STS-1 directly binds the peptide, two complementary approached were undertaken. In the first, purified STS-1 was subjected to limited proteolysis with thermolysin and the resulting fragments were incubated with the phosphorylated Tyr317 ShcA-derived peptide. A fragment that includes the region of STS-1 with homology to 2H phosphoesterases retained the ability to bind the peptide. In the second approach, mammalian cell lysates expressing STS-1 constructs with point mutations intended to disable individual domains of STS-1 were incubated the phosphorylated Tyr317 ShcA-derived peptide. STS-1 constructs with mutations in the domain with homology to 2HPEs failed to associate with the peptide.Chapter 4 describes the ability of STS-1 to dephosphorylate (or regulate dephosphorylation) of ShcA. We show that STS-1 can dephosphorylate tyrosine residues of ShcA in vitro. Additionally, we show that depletion of STS-1 results in enhanced ShcA tyrosine phosphorylation and enhanced Akt activation in mammalian cells.In summary, my results demonstrate that STS-1 binds directly to ShcA in a phosphotyrosine-dependent manner and that STS-1 may also be a physiologically relevant ShcA-phosphatase.

Merkel cell carcinoma is a rare and aggressive primary neuroendocrine carcinoma of the skin, whose pathogenesis can be traced back to UV radiation damage or Merkel cell polyomavirus (MCPyV) infection. Despite some improvements on the characterization of the disease partly due to its increased incidence, crucial pathogenetic and prognostic factors still need to be refined. A consecutive series of 228 MCC from three hospitals in Turin was collected with the aim of both analyzing the apparent increase in MCC incidence in our area and investigating the distribution and prognostic role of clinical-pathological parameters, with a focus on MCPyV status, ALK tumor expression and tumor infiltrating lymphocytes (TILs). Review of morphology and conventional immunohistochemical staining was possible in 191 cases. In 50 cases, the expression of the novel neuroendocrine marker INSM1 was additionally assessed. Fourteen cases of MCC of unknown primary skin lesion were identified and separately analyzed. While confirming an exponential trend in MCC incidence in the last decades and providing a description of histological and cytological features of a large series of MCC, the present study concludes that 1) INSM1 is a highly sensitive marker in both skin and lymph node primary MCC; 2) positive MCPyV status, brisk TILs and lower tumor size and thickness are independent positive prognostic parameters, and the combination of the former two may provide a novel tool for prognostic stratification; 3) ALK is expressed 87% of MCC and associated with positive viral status, and could represent a prognostic biomarker, if validated in larger series.

Gastrointestinal stromal tumors; MiRNAs; MicroRNAs Tumores del estroma gastrointestinal; MiARN; MicroARN Tumors de l'estroma gastrointestinal; MiARN; MicroARN Gastrointestinal stromal tumors (GISTs) harboring mutations in the PDGFRA gene occur in only about 5–7% of patients. The most common PDGFRA mutation is exon 18 D842V, which is correlated with specific clinico-pathological features compared to the other PDGFRA mutated GISTs. Herein, we present a miRNA expression profile comparison of PDGFRA D842V mutant GISTs and PDGFRA with mutations other than D842V (non-D842V). miRNA expression profiling was carried out on 10 patients using a TLDA miRNA array. Then, miRNA expression was followed by bioinformatic analysis aimed at evaluating differential expression, pathway enrichment, and miRNA-mRNA networks. We highlighted 24 differentially expressed miRNAs between D842V and non-D842V GIST patients. Pathway enrichment analysis showed that deregulated miRNAs targeted genes that are mainly involved in the immune response pathways. The miRNA-mRNA networks highlighted a signature of miRNAs/mRNA that could explain the indolent behavior of the D842V mutated GIST. The results highlighted a different miRNA fingerprint in PDGFRA D842V GISTs compared to non-D842Vmutated patients, which could explain the different biological behavior of this GIST subset. The study was supported by a financial contribution of the Department of Pharmacy and Biotechnology (RFO) to SA and of the AIG (Associazione Italiana GIST) to MA.

© The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/., Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.

Patients diagnosed with anaplastic large cell lymphoma (ALCL) are still treated with toxic multi-agent chemotherapy and as many as 25-50% of patients relapse. To understand disease pathology and to uncover novel targets for therapy, we performed whole-exome sequencing of anaplastic lymphoma kinase (ALK)+ ALCL, as well as gene-set enrichment analysis. This revealed that the T-cell receptor and Notch pathways were the most enriched in mutations. In particular, variant T349P of NOTCH1, which confers a growth advantage to cells in which it is expressed, was detected in 12% of ALK+ and ALK– ALCL patients’ samples. Furthermore, we demonstrated that NPM-ALK promotes NOTCH1 expression through binding of STAT3 upstream of NOTCH1. Moreover, inhibition of NOTCH1 with γ- secretase inhibitors or silencing by short hairpin RNA leads to apoptosis; cotreatment in vitro with the ALK inhibitor crizotinib led to additive/synergistic antitumor activity suggesting that this may be an appropriate combination therapy for future use in the circumvention of ALK inhibitor resistance. Indeed, crizotinib-resistant and -sensitive ALCL were equally sensitive to γ-secretase inhibitors. In conclusion, we show a variant in the extracellular domain of NOTCH1 that provides a growth advantage to cells and confirm the suitability of the Notch pathway as a second-line druggable target in ALK+ ALCL.

In the scenario of systemic treatment for advanced non-small cell lung cancer (NSCLC) patients, one of the most relevant breakthroughs is represented by targeted therapies. Throughout the last years, inhibitors of the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-Ros oncogene 1 (ROS1), and V-raf murine sarcoma viral oncogene homolog B (BRAF) have been approved and are currently used in clinical practice. However, other promising molecular drivers are rapidly emerging as therapeutic targets. This review aims to cover the molecular alterations with a potential clinical impact in NSCLC, including amplifications or mutations of the mesenchymal–epithelial transition factor (MET), fusions of rearranged during transfection (RET), rearrangements of the neurotrophic tyrosine kinase (NTRK) genes, mutations of the Kirsten rat sarcoma viral oncogene (KRAS) and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA), as well as amplifications or mutations of human epidermal growth factor receptor 2 (HER2). Additionally, we summarized the current status of targeted agents under investigation for such alterations. This revision of the current literature on emerging molecular targets is needed as the evolving knowledge on novel actionable oncogenic drivers and targeted agents is expected to increase the proportion of patients who will benefit from tailored therapeutic approaches.

This study determined the frequency and the clinicopathologic and genetic features of colorectal carcinomas driven by oncogenic fusions of the anaplastic lymphoma kinase gene (ALK). Of the 8150 screened tumors, 12 (0.15%) were immunohistochemically ALK-positive with D5F3 antibody. These cancers harbored CAD-ALK (n=1), DIAPH2-ALK (n=2), EML4-ALK (n=2), LOC101929227-ALK (n=1), SLMAP-ALK (n=1), SPTBN1-ALK (n=4), and STRN-ALK (n=1) fusions, as detected by an RNA-based next-generation sequencing assay. ALK fusion carcinomas were diagnosed mostly in older patients with a 9:3 female predominance (median age: 72 y). All tumors, except a rectal one, occurred in the right colon. Most tumors were stage T3 (n=7) or T4 (n=3). Local lymph node and distant metastases were seen at presentation in 9 and 2 patients. These tumors showed moderate (n=6) or poor (n=3) glandular differentiation, solid medullary growth pattern (n=2), and pure mucinous morphology (n=1). DNA mismatch repair-deficient phenotype was identified in 10 cases. Tumor-infiltrating lymphocytes were prominent in 9 carcinomas. In 4 carcinomas, tumor cells showed strong, focal (n=3), or diffuse programmed death-ligand 1 immunoreactivity. CDX2 expression and loss of CK20 and MUC2 expression were frequent. CK7 was expressed in 5 tumors. Four patients died of disease within 3 years, and 7 were alive with follow-up ranging from 1 to 8 years. No mutations in BRAF, RAS, and in genes encoding components of PI3K-AKT/MTOR pathway were identified. However, 1 tumor had a loss-of-function PTEN mutation. Aberration of p53 signaling, TP53 mutations, and/or nuclear accumulation of p53 protein was seen in 9 cases. ALK fusion colorectal carcinomas are a distinct and rare subtype of colorectal cancers displaying some features of mismatch repair-deficient tumors.

Anaplastic large-cell lymphoma (ALCL) is a clinical and biological heterogeneous disease that includes systemic anaplastic lymphoma kinase (ALK)-positive and ALK-negative entities. To discover biomarkers and/or genes involved in ALK-negative ALCL pathogenesis, we applied the cancer outlier profile analysis algorithm to a gene expression profiling data set including 249 cases of T-cell non-Hodgkin lymphoma and normal T cells. Ectopic coexpression of ERBB4 and COL29A1 genes was detected in 24% of ALK-negative ALCL patients. RNA sequencing and 5' RNA ligase-mediated rapid amplification of complementary DNA ends identified 2 novel ERBB4-truncated transcripts displaying intronic transcription start sites. By luciferase assays, we defined that the expression of ERBB4-aberrant transcripts is promoted by endogenous intronic long terminal repeats. ERBB4 expression was confirmed at the protein level by western blot analysis and immunohistochemistry. Lastly, we demonstrated that ERBB4-truncated forms show oncogenic potentials and that ERBB4 pharmacologic inhibition partially controls ALCL cell growth and disease progression in an ERBB4-positive patient-derived tumorgraft model. In conclusion, we identified a new subclass of ALK-negative ALCL characterized by aberrant expression of ERBB4-truncated transcripts carrying intronic 5' untranslated regions. © 2016 by The American Society of Hematology.

ZNF224 is a KRAB-zinc finger transcription factor that exerts a key tumor suppressive role in chronic myelogenous leukemia. In this study, we identify the receptor tyrosine kinase Axl as a novel target of ZNF224 transcriptional repression activity. Axl overexpression is found in many types of cancer and is frequently associated with drug resistance. Interestingly, we also found that sensitivity to imatinib can be partly restored in imatinib-resistant chronic myelogenous leukemia cells by ZNF224 overexpression and the resulting suppression of Axl expression. These results, in accordance with our previous findings, support the role of ZNF224 in imatinib responsiveness and shed new insights into potential therapeutic use of ZNF224 in imatinib-resistant chronic myelogenous leukemia.

Introduction: Receptor tyrosine kinases (RTKs) and their signaling pathways, control normal cellular processes; however, their deregulation play important roles in malignant transformation. In advanced non-small cell lung cancer (NSCLC), the recognition of oncogenic activation of specific RTKs, has led to the development of molecularly targeted agents that only benefit roughly 20% of patients. Entrectinib is a pan-TRK, ROS1 and ALK inhibitor that has shown potent anti-neoplastic activity and tolerability in various neoplastic conditions, particularly NSCLC. Areas covered: This review outlines the pharmacokinetics, pharmacodynamics, mechanism of action, safety, tolerability, pre-clinical studies and clinical trials of entrectinib, a promising novel agent for the treatment of advanced solid tumors with molecular alterations of Trk-A, B and C, ROS1 or ALK. Expert opinion: Among the several experimental drugs under clinical development, entrectinib is emerging as an innovative and promising targeted agent. The encouraging antitumor activity reported in the Phase 1 studies, together with the acceptable toxicity profile, suggest that entrectinib, thanks to its peculiar mechanism of action, could play an important role in the treatment-strategies of multiple TRK-A, B, C, ROS1, and ALK-dependent solid tumors, including NSCLC and colorectal cancer. That being said, further evidence for its clinical use is still needed.

Introduction: ALK rearranged Non Small Cell Lung Cancers (NSCLCs) represent a distinct subgroup of patients with peculiar clinic-pathological features. These patients exhibit dramatic responses when treated with the ALK tyrosine kinase inhibitor Crizotinib, albeit Central Nervous System (CNS) activity is much less impressive than that observed against extracranial lesions. CNS involvement has become increasingly observed in these patients, given their prolonged survival. Several novel generation ALK inhibitors have been developing to increase CNS penetration and to provide more complete ALK inhibition. Areas covered: The CNS activity of Crizotinib and novel generation ALK inhibitors will be summarized in this review, evaluating the strengths and weaknesses of the therapeutic strategies developed to date in this specific subgroup of NSCLCs with a look towards the future. Expert commentary: In the next few years, the results of ongoing comparative head-to-head trials will provide the definitive conclusions on the optimal treatment sequence in ALK-rearranged NSCLCs. Moreover, ongoing clinical trials with novel-generation ALK inhibitors will produce more evidences on the best approach in the growing number of ALK-positive NSCLCs with CNS involvement.

Background The identification of ALK and ROS1 rearrangements and the availability of an effective target therapy, such as crizotinib, represent a new option in the treatment of advanced non-small cell lung cancer (NSCLC) patients. In light of recent advances in non-invasive diagnostic procedures, we aimed to demonstrate that direct cytological smears are suitable for assessing ALK and ROS1 rearrangements in patients with NSCLC. Methods Fifty-five patients with a cytological diagnosis of lung adenocarcinoma (ADC) were evaluated for ALK rearrangements by fluorescence in situ hybridization (FISH) and 12 patients for ROS1 FISH rearrangements. Seventeen of the 55 cytological samples tested for ALK were obtained from the primary tumor and 38 from metastatic lesions. Ten of 12 samples evaluated for ROS1 were obtained from metastatic sites and two from the primary tumor. Results ALK FISH was successful in 49/55 (89%) cytological ADC samples and ROS1 FISH in all 12 cytological samples. ALK rearrangements were found in 3/13 (23%) primary tumors and 7/36 (19%) metastatic sites. ROS1 rearrangements were found in one of the two primary tumors and in two of the 10 metastases. Two of the three rearranged cases were tested on cytology after knowing that they were rearranged on histology in order to increase representativeness of ROS1 rearranged cases in this study. Conclusion Whenever cytology represents the only available material for diagnosis and biological characterization of NSCLC, minimally invasive procedures may provide an additional important source of cellular material for FISH assessment of ALK and ROS1 rearrangements.

Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kappa B (NF kappa B) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NF kappa B gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NF kappa B signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies.

We verified the hypothesis that changes in the endogenous GM1 ganglioside density in the environment of TrkB, receptor of brain-derived neurotrophic factor, can affect receptor activity, and focused on rat cerebellar granule cells expressing both GM1 and TrkB. Changes of the amount of GM1 associated to immunoprecipitated TrkB and of receptor tyrosine phosphorylation were evaluated after treatment with phorbol-12-myristate-13-acetate (1 μM, 7 min), reported to affect the plasma membrane distribution of endogenous gangliosides in the same cells. After treatment, the amount of GM1 associated to receptor and TrkB phosphorylation decreased by about 40%. The amount of associated GM1 decreased by about 33% also after concomitant treatment with phorbol ester and brain-derived neurotrophic factor, but in this case the neurotrophin was unable to enhance receptor tyrosine phosphorylation. These results for the first time suggest that changes in the amount of endogenous GM1 in the environment of TrkB can modulate receptor activity, and offer new clues for a better understanding of physiological and pathological events of the nervous system.

Introduction/Background Patients with advanced NSCLC who experience disease progression after second-line therapy might receive further active treatment. LIFE was an Italian cohort multicenter observational study composed of a cross-sectional and a longitudinal phase. Patients and Methods In the longitudinal phase, described here, the primary aim was to determine the proportion of patients receiving third-line therapy among those who received second-line active treatment according to clinical practice. The proportion of patients receiving further treatment lines was also estimated. Results The longitudinal phase was conducted between January and August 2012. Of 464 patients who began second-line therapy outside of clinical trials within the baseline evaluation, 56 (12.1%) were still receiving second-line therapy at the end of the observation period and 17 (3.7%) withdrew during or after second-line therapy. Of the remaining 391 patients, 158 (40.4%) received third-line treatment outside of clinical trials: 93 received a third-line chemotherapy and 65 a targeted agent. The main reason for interrupting third-line treatment was disease progression or death. During the same observation period, 25 of 113 patients who completed a third-line therapy received a fourth line of treatment. From diagnosis of NSCLC to the end of observation, biomarkers were tested in 323 patients (59.7%): epidermal growth factor receptor mutations in 315 (58.2%), Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutations in 83 (15.3%) and Anaplastic lymphoma kinase (ALK) translocation in 84 (15.5%). Conclusion In Italian clinical practice, the proportion of patients with advanced NSCLC receiving more than 2 treatment lines of therapy is not negligible.

PURPOSE: LIFE (non-small cell Lung cancer management In patients progressing after First-linE of treatment in the metastatic setting) is a multicentre Italian observational study, including a cross-sectional and a longitudinal phase, with the aim of describing the therapeutic approach in clinical practice for advanced non-small cell lung cancer (NSCLC) patients, progressing after first-line treatment. METHODS: In this paper, the cross-sectional phase is outlined, with the primary endpoint of describing the proportion of patients receiving second-line treatment among those progressed during or after first-line treatment according to clinical practice. RESULTS: From July 2011 to January 2012, 603 patients were enrolled and 541 (90 %) were evaluable. A total of 464 (86 %) patients received a second-line therapy outside clinical trials. Chemotherapy and targeted therapies were administered to 65 and 34 % of patients, respectively (1 % both). No tissue collection was required within the observational trial, and biomarkers analysis was performed at diagnosis or later in 314 patients (58 %). In details, activating epidermal growth factor receptor mutations were detected in 21 % of 311 evaluable patients, Kirsten rat sarcoma 2 viral oncogene homolog mutation in 22 % of the 77 evaluable patients and anaplastic lymphoma kinase translocations analysis was performed in 74 patients and resulted positive in 23 % of cases. These high proportions were probably due to enriched patient population tested. CONCLUSIONS: These results showed a pattern of care for NSCLC second-line therapy which reflects international guidelines recommendations and current expected clinical practice. Interestingly, biomarkers analyses were performed in a higher percentage than expected.

INTRODUCTION: Recent clinical trials led to the approval of crizotinib (PF-02341066; Pfizer) by the U.S. Food and Drug Administration for the treatment of locally advanced or metastatic non-small-cell lung cancer (NSCLC) patients whose tumors are positive for anaplastic lymphoma kinase (ALK) alterations. The European Medicines Agency accepted the regulatory submission of crizotinib for the treatment of these patients. Therefore, ALK gene testing has become mandatory to choose the most appropriate therapy. METHODS: To help physicians, involved in the management of NSCLC patients to be treated with ALK inhibitors in Italy, the Italian Association of Medical Oncology and the Italian Society of Pathology and Cytopathology identified a large panel of Italian medical oncologists and pathologists that outlined recommendations for ALK testing in NSCLC patients. RESULTS: The guidelines produced include specific information on the target patient population, the biological material for molecular analysis, a section dedicated to the histocytopathologic diagnosis of NSCLC, and the methods for the assessment of ALK alterations that are summarized in this article. CONCLUSIONS: Clinicopathologic recommendations were produced to guide the management of NSCLC patients who need to be tested for ALK rearrangements before treatment with ALK inhibitors. Copyright © 2013 by the International Association for the Study of Lung Cancer.

SummaryReceptor tyrosine kinases (RTK) are targets for anticancer drug development. To date, only RTK inhibitors that block orthosteric binding of ligands and substrates have been developed. Here, we report the pharmacologic characterization of the chemical SSR128129E (SSR), which inhibits fibroblast growth factor receptor (FGFR) signaling by binding to the extracellular FGFR domain without affecting orthosteric FGF binding. SSR exhibits allosteric properties, including probe dependence, signaling bias, and ceiling effects. Inhibition by SSR is highly conserved throughout the animal kingdom. Oral delivery of SSR inhibits arthritis and tumors that are relatively refractory to anti-vascular endothelial growth factor receptor-2 antibodies. Thus, orally active, extracellularly acting small-molecule modulators of RTKs with allosteric properties can be developed and may offer opportunities to improve anticancer treatment.

OBJETIVO: Descrever a metodologia para detecção de mutações nos éxons 8 e 17 do gene KIT em pacientes portadores de leucemia mieloide aguda, para implementação desse teste no laboratório clínico do Hospital Israelita Albert Einstein. MÉTODOS: Extração do DNA genômico de 54 amostras de sangue periférico ou medula óssea de pacientes com leucemia mieloide aguda para amplificação, por reação em cadeia da polimerase, sequenciamento e análise de fragmentos. RESULTADOS: Dentre as amostras analisadas, quatro apresentaram mutação no éxon 8, duas no éxon 17 e uma amostra apresentou mutação nos dois éxons. CONCLUSÃO: A pesquisa de mutação nos éxons 8 e 17 do gene KIT foi padronizada com sucesso e o teste está em processo de inclusão no menu de exames do laboratório clínico do Hospital Israelita Albert Einstein. OBJECTIVE: This study describes a new method used in the clinical laboratory at Hospital Israelita Albert Einstein to detect mutations in exons 8 and 17 of the KIT gene in patients with acute myeloid leukemia. METHODS: Genomic DNA extraction was performed on 54 samples of peripheral blood or bone marrow from patients with acute myeloid leukemia. The extracted DNA was amplified by polymerase chain reaction and sequenced, and the fragments were analyzed. RESULTS: Within the analyzed samples, we detected four mutations in exon 8, two mutations in exon 17, and mutations or a double mutation in one sample. CONCLUSION: The tests detecting mutations in exon 8 and 17 on the KIT gene were successfully standardized. The test is now included among the routine diagnostics employed for patients at Hospital Israelita Albert Einstein clinical laboratory.

Introduction: Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase normally expressed in the developing nervous tissue. Genetic alterations of ALK are associated with a number of cancers, including anaplastic large cell lymphoma (ALCL) and a subset of non-small cell lung cancer (NSCLC). Standard therapies for these diseases include surgery plus unspecific cytotoxic agents, with a low therapeutic window and significant treatment-associated systemic toxicity. A few small-molecule inhibitors of ALK kinase activity have been described in the recent years, some of which are currently undergoing clinical evaluation. Areas covered: Literature was searched for all ALK inhibitors that have entered clinical investigation, including published research articles and meeting abstracts. Data on pharmacokinetics, safety and efficacy of crizotinib, as well as preliminary clinical data for second-generation compounds, are reviewed. The issue of drug resistance is discussed. Expert opinion: Understanding the specific genetic aberration that causes cancer development and progression allows major advances in cancer therapy. Along the same way shown by imatinib in chronic myeloid leukemia, compounds that selectively target ALK are bringing a revolution in the treatment of ALK-positive tumors. Crizotinib has just been approved, and new more potent ALK inhibitors will shortly follow. These molecules represent another excellent proof-of-principle for targeted therapy. © 2012 Informa UK, Ltd

To highlight possible similarities and differences in receptor tyrosine kinase (RTK) and downstream signalling activation profiles between clear-cell sarcomas (CCS) and metastatic melanomas (MM), frozen, and paired-matched fixed samples of six CCS with EWSR1 rearrangement (EWSR1+), five CCS without EWSR1 rearrangement (EWSR1-), and seven MM were investigated by means of biochemical, immunohistochemical, FISH, molecular analyses, and immunofluorescence confocal microscopy. Fixed samples of a further 10 CCS and 14 MM were investigated by means of sequencing for BRAF, NRAS, and KRAS mutations and FISH analyses for the gain of chromosomes 22 and 8. RTK analysis of all CCS/MM samples showed activation of short-form (sf) recepteur d'origine nantais (RON) RTK and of PDGFRB, MET, and HER3. Analysis of downstream signaling revealed consistent phosphorylation patterns of PI3K/AKT, RSK, and the mTOR targets S6 and 4EBP1. Analysis of frozen and fixed material from 21 CCS and 21 MM showed the presence of the V600E BRAF mutation in 2/12 EWSR1+ and 3/9 EWSR1- CCS and 9/21 MM and demonstrated a significant (P < 0.001) correlation between the gain of chromosomes 22 and 8 and EWSR1- CCS. Our results show that BRAF mutation can also be present in CCS and support the proposed aberration of chromosomes 22 and 8 as a possibly useful nonrandom hallmark of EWSR1- CCS. Besides, they broaden the spectrum of the similarities of RTK pathway activation between CCS and MM, thus suggesting that new drugs found to be active in melanoma and RON inhibitors could have a role in CCS treatment. © 2011 Wiley Periodicals, Inc.

In anaplastic large-cell lymphomas, chromosomal translocations involving the kinase domain of anaplastic lymphoma kinase (ALK), generally fused to the 5' part of the nucleophosmin gene, produce highly oncogenic ALK fusion proteins that deregulate cell cycle, apoptosis, and differentiation in these cells. Other fusion oncoproteins involving ALK, such as echinoderm microtubule-associated protein-like 4-ALK, were recently found in patients with non-small-cell lung, breast, and colorectal cancers. Recent research has focused on the development of inhibitors for targeted therapy of these ALK-positive tumors. Because kinase inhibitors that target the inactive conformation are thought to be more specific than ATP-targeted inhibitors, we investigated the possibility of using two known inhibitors, doramapimod and sorafenib, which target inactive kinases, to design new urea derivatives as ALK inhibitors. We generated a homology model of ALK in its inactive conformation complexed with doramapimod or sorafenib in its active site. The results elucidated why doramapimod is a weak inhibitor and why sorafenib does not inhibit ALK. Virtual screening of commercially available compounds using the homology model of ALK yielded candidate inhibitors, which were tested using biochemical assays. Herein we present the design, synthesis, biological activity, and structure-activity relationships of a novel series of urea compounds as potent ALK inhibitors. Some compounds showed inhibition of purified ALK in the high nanomolar range and selective antiproliferative activity on ALK-positive cells.

Our aim was to assess the activation profile of EGFR, PDGFRB and PDGFRA receptor tyrosine kinases (RTK) and their downstream effectors in a series of cryopreserved diffuse malignant peritoneal mesothelioma (DMPM) surgical specimens to discover the targets for drug inhibition. We also made a complementary analysis of the cytotoxic effects of some kinase inhibitors on the proliferation of the human peritoneal mesothelioma STO cell line. We found the expression/phosphorylation of EGFR and PDGFRB in most of the tumours, and PDGFRA activation in half. The expression of the cognate ligands TGF-α, PDGFB and PDGFA in the absence of RTK mutation and amplification suggested the presence of an autocrine/paracrine loop. There was also evidence of EGFR and PDGFRB co-activation. RTK downstream signalling analysis demonstrated the activation/expression of ERK1/2, AKT and mTOR, together with S6 and 4EBP1, in almost all the DMPMs. No KRAS/BRAF mutations, PI3KCA mutations/amplifications or PTEN inactivation were observed. Real-time polymerase chain reaction revealed the decreased expression of TSC1 c-DNA in half of the tumours. In vitro cytotoxicity studies showed the STO cell line to be resistant to gefitinib and sensitive to sequential treatment with RAD001 and sorafenib; these findings were consistent with the presence of the KRAS mutation G12D in these cells although it was not detectable in the original tumour. Our results highlight the ligand-dependent activation and co-activation of EGFR and PDGFRB, as well as a connection between these activated RTKs and the downstream mTOR pathway, thus supporting the role of combined treatment with RTK and mTOR inhibitors in DMPM.