Anaplastic Lymphoma Kinase Receptor Tyrosine Kinase Research Articles

Anaplastic Lymphoma Kinase signaling stabilizes SLC3A2 expression via MARCH11 to promote neuroblastoma cell growth

Solute Carrier Family 3, Member 2 (SLC3A2 or 4F2hc) is a multifunctional glycoprotein that mediates integrin-dependent signaling, acts as a trafficking chaperone for amino acid transporters, and is involved in polyamine transportation. We identified SLC3A2 as a potential Anaplastic Lymphoma Kinase (ALK) interacting partner in a BioID-proximity labeling screen in neuroblastoma (NB) cells. In this work we show that endogenous SLC3A2 and ALK interact in NB cells and that this SLC3A2:ALK interaction was abrogated upon treatment with the ALK inhibitor lorlatinib. We show here that loss of ALK activity leads to decreased SLC3A2 expression and reduced SLC3A2 protein stability in a panel of NB cell lines, while stimulation of ALK with ALKAL2 ligand resulted in increased SLC3A2 protein levels. We further identified MARCH11, an E3 ligase, as a regulator of SLC3A2 ubiquitination downstream of ALK. Further, knockdown of SLC3A2 resulted in inhibition of NB cell growth. To investigate the therapeutic potential of SLC3A2 targeting, we performed monotreatment of NB cells with AMXT-1501 (a polyamine transport inhibitor), which showed only moderate effects in NB cells. In contrast, a combination lorlatinib/AMXT-1501 treatment resulted in synergistic inhibition of cell growth in ALK-driven NB cell lines. Taken together, our results identify a novel role for the ALK receptor tyrosine kinase (RTK), working in concert with the MARCH11 E3 ligase, in regulating SLC3A2 protein stability and function in NB cells. The synergistic effect of combined ALK and polyamine transport inhibition shows that ALK/MARCH11/SLC3A2 regulation of amino acid transport is important for oncogenic growth and survival in NB cells.

NGPF2 triggers synaptic scaling up through ALK-LIMK-cofilin-mediated mechanisms.

Synaptic scaling is an extensively studied form of homeostatic plasticity critically involved in various brain functions. Although it is accepted that synaptic scaling is expressed through the postsynaptic accumulation of AMPA receptors (AMPARs), the induction mechanism remains elusive. In this study, we show that TTX treatment induces rapid but transient release of the neurite growth-promoting factor 2 (NGPF2), and this release is necessary and sufficient for TTX-induced scaling up. In addition, we show that inhibition of the anaplastic lymphoma kinase (ALK)-LIMK-cofilin signaling pathway blocks TTX- and NGPF2-induced synaptic scaling up. Furthermore, we show that TTX-induced release of NGPF2 is protein synthesis dependent and requires fragile X mental retardation protein 1 (FMRP1). These results indicate that activity blockade induces NGPF2 synthesis and release to trigger synaptic scaling up through LIMK-cofilin-dependent actin reorganization, spine enlargement, and stabilization of AMPARs at the synapse.

Abstract A36: Targeting anaplastic lymphoma kinase in neuroblastoma

Abstract Over the last decade Anaplastic Lymphoma Kinase (ALK), a receptor tyrosine kinase (RTK), has been identified as a fusion partner in a diverse variety of translocation events resulting in oncogenic signaling in many different cancer types. In tumors where full-length ALK RTK itself is mutated, such as neuroblastoma, the picture regarding the role of ALK as an oncogenic driver is less clear. Neuroblastoma is a complex and heterogeneous tumor that arises from the neural crest-derived peripheral nervous system. Although high-risk neuroblastoma is rare, it often relapses and becomes refractory to treatment. Thus, neuroblastoma accounts for 10-15% of all childhood cancer deaths. Since most cases are in children under the age of two, understanding the role and regulation of ALK during neural crest development is an important goal in addressing neuroblastoma tumorigenesis. An impressive array of tyrosine kinase inhibitors (TKIs) that act to inhibit ALK have been FDA approved for using in ALK-driven cancers. ALK TKIs bind differently within the ATP-binding pocket of the ALK kinase domain and have been associated with different resistance mutations within ALK itself that arise in response to therapeutic use, particularly in ALK fusion-positive NSCLC. This patient population has highlighted the importance of considering the relevant ALK TKI to be used for a given ALK mutant variant. In this poster we discuss ALK in neuroblastoma, as well as the use of ALK TKIs and other strategies to inhibit tumor growth. Current efforts combining novel approaches and increasing our understanding of the oncogenic role of ALK in neuroblastoma are aimed at improving efficacy of ALK TKIs as precision medicine options in the clinic. Citation Format: Jikui Guan, Diana Cervantes-Madrid, Joachim Siaw, Wasi Alam, Ganesh Umapathy, Marcus Borenäs, Dan Lind, Joanna Szydzik, Kathrin Pfeifer, Patricia Mendoza-Garcia, Ruth Palmer, Bengt Hallberg. Targeting anaplastic lymphoma kinase in neuroblastoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A36.

Coordination Among Multiple Receptor Tyrosine Kinase Signals Controls <i>Drosophila</i> Developmental Timing and Body Size

SummaryBody size and the timing of metamorphosis are two important interlinked life-history traits that define holometabolous insect development. Metamorphic timing is largely controlled by a neuroendocrine signaling axis composed of the prothoracic gland (PG) and its presynaptic neurons (PGNs). The PGNs produce prothoracicotropic hormone (PTTH) that stimulates the PG to produce the metamorphosis inducing hormone ecdysone (E) through activation of Torso a Receptor Tyrosine Kinase (RTK) and its downstream Ras/Erk signal transducers. Here we identify two additional timing signals produced by the RTKs Anaplastic lymphoma kinase (Alk) and the PDGF/VEGF-receptor related (PvR). Similar to Torso, both Alk and PvR trigger Ras/Erk signaling in the PG to up-regulate expression of E biosynthetic enzymes, while Alk also suppresses autophagy induction after critical weight by activating Pi3K/Akt. When overexpressed, both RTKs hyperactivate an endogenous low-level Jak/Stat signal in the PG resulting in developmental delay or arrest. The Alk ligand Jelly belly (Jeb) is produced by the PGNs and, together with PTTH, serves as a second PGN derived tropic factor that stimulates E production by the PG. In addition, we find that Pvf3, a PvR ligand, is also produced by the PGNs, but we show that the activation of PvR primarily relies on autocrine signaling by PG-derived Pvf2 and Pvf3. These findings illustrate that a multitude of juxtacrine and autocrine signaling systems have evolved to regulate the timing of metamorphosis, the defining event of holometabolous development.

Anaplastic Lymphoma Kinase Regulates Internalization of the Dopamine D2 Receptor.

The dopamine D2 receptor (D2R) is a G protein-coupled receptor (GPCR) expressed in regions of the brain that control motor function, cognition, and motivation. As a result, D2R is involved in the pathophysiology of disorders such as schizophrenia and drug addiction. Understanding the signaling pathways activated by D2R is crucial to finding new therapeutic targets for these disorders. D2R stimulation by its agonist, dopamine, causes desensitization and internalization of the receptor. A previous study found that inhibitors of the receptor tyrosine kinase anaplastic lymphoma kinase (ALK) blocked D2R desensitization in neurons in the ventral tegmental area of the brain. In the present study, using a cell-based system, we investigated whether ALK regulates D2R internalization. The ALK inhibitor alectinib completely inhibited dopamine-induced D2R internalization. Since GPCRs can transactivate receptor tyrosine kinases, we also examined if D2R stimulation activated ALK signaling. ALK phosphorylation increased by almost 2-fold after dopamine treatment and ALK coimmunoprecipitated with D2R. To identify the signaling pathways downstream of ALK that might regulate D2R internalization, we used pharmacological inhibitors of proteins activated by ALK signaling. Protein kinase Cγ was activated by dopamine in an ALK-dependent manner, and a protein kinase C inhibitor completely blocked dopamine-induced D2R internalization. Taken together, these results identify ALK as a receptor tyrosine kinase transactivated by D2R that promotes its internalization, possibly through activation of protein kinase C. ALK inhibitors could be useful in enhancing D2R signaling. SIGNIFICANCE STATEMENT: Receptor internalization is a mechanism by which receptors are desensitized. In this study we found that agonist-induced internalization of the dopamine D2 receptor is regulated by the receptor tyrosine kinase ALK. ALK was also transactivated by and associated with dopamine D2 receptor. Dopamine activated protein kinase C in an ALK-dependent manner and a PKC inhibitor blocked dopamine D2 receptor internalization. These results indicate that ALK regulates dopamine D2 receptor trafficking, which has implications for psychiatric disorders involving dysregulated dopamine signaling.

Analysis of ALK, MYCN, and the ALK ligand ALKAL2 (FAM150B/AUGα) in neuroblastoma patient samples with chromosome arm 2p rearrangements.

Gain of chromosome arm 2p is a previously described entity in neuroblastoma (NB). This genomic address is home to two important oncogenes in NB-MYCN and anaplastic lymphoma kinase (ALK). MYCN amplification is a critical prognostic factor coupled with poor prognosis in NB. Mutation of the ALK receptor tyrosine kinase has been described in both somatic and familial NB. Here, ALK activation occurs in the context of the full-length receptor, exemplified by activating point mutations in NB. ALK overexpression and activation, in the absence of genetic mutation has also been described in NB. In addition, the recently identified ALK ligand ALKAL2 (previously described as FAM150B and AUGα) is also found on the distal portion of 2p, at 2p25. Here we analyze 356 NB tumor samples and discuss observations indicating that gain of 2p has implications for the development of NB. Finally, we put forward the hypothesis that the effect of 2p gain may result from a combination of MYCN, ALK, and the ALK ligand ALKAL2.

Targeting anaplastic lymphoma kinase in neuroblastoma.

Over the last decade, anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase (RTK), has been identified as a fusion partner in a diverse variety of translocation events resulting in oncogenic signaling in many different cancer types. In tumors where the full‐length ALK RTK itself is mutated, such as neuroblastoma, the picture regarding the role of ALK as an oncogenic driver is less clear. Neuroblastoma is a complex and heterogeneous tumor that arises from the neural crest derived peripheral nervous system. Although high‐risk neuroblastoma is rare, it often relapses and becomes refractory to treatment. Thus, neuroblastoma accounts for 10–15% of all childhood cancer deaths. Since most cases are in children under the age of 2, understanding the role and regulation of ALK during neural crest development is an important goal in addressing neuroblastoma tumorigenesis. An impressive array of tyrosine kinase inhibitors (TKIs) that act to inhibit ALK have been FDA approved for use in ALK‐driven cancers. ALK TKIs bind differently within the ATP‐binding pocket of the ALK kinase domain and have been associated with different resistance mutations within ALK itself that arise in response to therapeutic use, particularly in ALK‐fusion positive non‐small cell lung cancer (NSCLC). This patient population has highlighted the importance of considering the relevant ALK TKI to be used for a given ALK mutant variant. In this review, we discuss ALK in neuroblastoma, as well as the use of ALK TKIs and other strategies to inhibit tumor growth. Current efforts combining novel approaches and increasing our understanding of the oncogenic role of ALK in neuroblastoma are aimed at improving the efficacy of ALK TKIs as precision medicine options in the clinic.

CUX1-ALK, a Novel ALK Rearrangement That Responds to Crizotinib in Non–Small Cell Lung Cancer

IntroductionLung cancer is the leading cause of cancer-related deaths worldwide. ALK receptor tyrosine kinase gene (ALK) rearrangement has been identified in 3% to 5% of patients with NSCLC. The most common ALK rearrangement is echinoderm microtubule associated protein like 4 (EML4)-ALK, with several variants that can be targeted by the tyrosine kinase inhibitor crizotinib. MethodsIn this study using comprehensive next-generation sequencing targeting 416 pan-cancer genes and introns of 16 genes frequently rearranged in cancer, we identified a novel cut-like homeobox 1 gene (CUX1)-ALK fusion gene in a patient with lung adenocarcinoma. The exact CUX1-ALK fusion transcript was determined by RNA sequencing and confirmed by reverse-transcriptase polymerase chain reaction. The oncogenic ability of CUX1-ALK fusion gene was further validated in cells of the line 293T for the activation of anaplastic lymphoma kinase (ALK) self-phosphorylation and downstream signaling pathways. ResultsAfter detection of the CUX1-ALK fusion gene, RNA sequencing analysis of formalin-fixed paraffin-embedded sections from the primary tumor specimen was applied to reveal a 97-nucleotide fragment from CUX1 intron 8 inserted before the nucleotide 53 position in ALK exon 20. Expression of the cut-like homeobox 1–ALK fusion protein in 293T cells confirmed the self-phosphorylation of the fusion protein and the activation of ALK downstream signaling pathways, including the mitogen-activated protein kinase, Janus kinase–signal transducer and activator of transcription, and phosphoinositide 3-kinase/AKT signaling pathways, which could all be inhibited by the addition of crizotinib. Furthermore, the patient showed a superior response to crizotinib, with a progression-free survival of 20 months. ConclusionsThis study provides the novel finding of a CUX1-ALK fusion gene from a patient with NSCLC that could provide personalized treatment solutions for the maximum benefit to patients with NSCLC.

Evaluation of NGS and RT-PCR Methods for ALK Rearrangement in European NSCLC Patients: Results from the European Thoracic Oncology Platform Lungscape Project.

The reported prevalence of ALK receptor tyrosine kinase gene (ALK) rearrangement in NSCLC ranges from 2% to 7%. The primary standard diagnostic method isfluorescence in situ hybridization (FISH). Recently, immunohistochemistry (IHC) has also proved to be a reproducible and sensitive technique. Reverse-transcriptase polymerase chain reaction (RT-PCR) has also been advocated, and most recently, the advent of targeted next-generation sequencing (NGS) for ALK and other fusions has become possible. This study compares anaplastic lymphoma kinase (ALK) evaluation with all four techniques in resected NSCLC from the large European Thoracic Oncology Platform Lungscape cohort. A total of 96 cases from the European Thoracic Oncology Platform Lungscape iBiobank, with any ALK immunoreactivity were examined by FISH, central RT-PCR, and NGS. An H-score higher than 120 defines IHC positivity. RNA was extracted from the same formalin-fixed, paraffin-embedded tissues. For RT-PCR, primers covered the most frequent ALK translocations. For NGS, the Oncomine Solid Tumour Fusion Transcript Kit (Thermo Fisher Scientific, Waltham, MA) was used. The concordance was assessed using the Cohen κ coefficient (two-sided α ≤ 5%). NGS provided results for 77 of the 95 cases tested (81.1%), whereas RT-PCR provided results for 77 of 96 (80.2%). Concordance occurred in 55 cases of the 60 cases tested with all four methods (43 ALK negative and 12 ALK positive). Using ALK copositivity for IHC and FISH as the criterion standard, we derived a sensitivity for RT-PCR/NGS of 70.0%/85.0%, with a specificity of 87.1%/79.0%. When either RT-PCR or NGS was combined with IHC, the sensitivity remained the same, whereas the specificity increased to 88.7% and 83.9% respectively. NGS evaluation with the Oncomine Solid Tumour Fusion transcript kit and RT-PCR proved to have high sensitivity and specificity, advocating their use in routine practice. For maximal sensitivity and specificity, ALK status should be assessed by using two techniques and a third one in discordant cases. We therefore propose a customizable testing algorithm. These findings significantly influence existing testing paradigms and have clear clinical and economic impact.

ASCEND-8: A Randomized Phase 1 Study of Ceritinib, 450 mg or 600 mg, Taken with a Low-Fat Meal versus 750 mg in Fasted State in Patients with Anaplastic Lymphoma Kinase (ALK)-Rearranged Metastatic Non–Small Cell Lung Cancer (NSCLC)

IntroductionCeritinib, 750 mg fasted, is approved for treatment of patients with ALK receptor tyrosine kinase gene (ALK)-rearranged (ALK-positive) NSCLC previously treated with crizotinib. Part 1 of the ASCEND-8 study determined whether administering ceritinib, 450 mg or 600 mg, with a low-fat meal may enhance gastrointestinal (GI) tolerability versus 750 mg fasted in patients with ALK-positive NSCLC while maintaining similar exposure. MethodsASCEND-8 is a multicenter, randomized, open-label, phase 1 study. Part 1 investigated the steady-state pharmacokinetics (PK) and safety of ceritinib, 450 mg or 600 mg, taken with a low-fat meal versus 750 mg fasted in patients with advanced ALK-positive NSCLC who were either treatment naive or pretreated with chemotherapy and/or crizotinib. Part 2 will assess efficacy and safety of ceritinib in treatment-naive patients. ResultsAs of June 16, 2016, 137 patients were randomized (450 mg fed [n = 44], 600 mg fed [n = 47], and 750 mg fasted [n = 46]); 135 patients received ceritinib. Median follow-up duration was 4.14 months. At steady state, relative to 750 mg fasted, 450 mg with food demonstrated comparable PK as assessed by maximum (peak) concentration of drug in plasma and area under the plasma concentration–time curve from time zero to 24 hours, whereas 600 mg with food demonstrated approximately 25% higher PK. Relative to 750 mg fasted, 450 mg with food was associated with a lower proportion of patients with GI toxicities, mostly grade 1 (diarrhea [43.2%], nausea [29.5%], and vomiting [18.2%]); there were no grade 3 or 4 events, study drug discontinuations, or serious AEs due to GI toxicities. ConclusionCeritinib, 450 mg with food, had similar exposure and a more favorable GI safety profile than ceritinib, 750 mg in fasted patients with ALK-positive NSCLC.

Therapeutic strategies and mechanisms of drug resistance in anaplastic lymphoma kinase (ALK)-rearranged lung cancer.

Anaplastic lymphoma kinase (ALK) gene encoding the receptor tyrosine kinase ALK is expressed as a fusion gene in a variety of carcinomas. The expression of ALK is nearly undetectable in adults, and its activation is normally regulated by its ligands, FAM150A/B. However, ALK gene rearrangements result in constitutive ALK fusion proteins expression via the active promoter of fusion partner genes. ALK fusion proteins dimerize in a ligand-independent manner and lead to the dysregulation of cell proliferation via abnormal constitutive activation of ALK tyrosine kinase. Many ALK tyrosine kinase inhibitors (TKIs) have been developed to date, three of which are currently in clinical use for the treatment of ALK-rearranged non-small cell lung cancer (NSCLC). ALK TKIs often achieve marked tumor regression in NSCLC patients with ALK rearrangements; however, ALK TKI-resistant tumors inevitably emerge within a few years in most cases. In this review, we summarize diverse ALK TKI resistance mechanisms identified in NSCLC with ALK rearrangements, and review potential therapeutic strategies to overcome ALK TKI resistance in these patients.

The Truncated Isoform of the Receptor Tyrosine Kinase ALK Generated by Alternative Transcription Initiation (ALKATI) Induces Chromatin Structural Changes in the Nucleus in a Kinase Activity-Dependent Manner.

Anaplastic lymphoma kinase (ALK) is a receptor-type tyrosine kinase that promotes cell growth upon stimulation with ligands such as midkine and pleiotrophin. Recently, a truncated isoform of ALK was identified in a variety of tumors. This isoform is expressed from a novel ALK transcript initiated from a de novo alternative transcription initiation (ATI) site in ALK intron 19 (referred to as ALKATI). ALKATI, which consists of only the intracellular kinase domain, localizes to the nucleus as well as the cytoplasm. However, its nuclear role is unknown. In this study, we determined that ALKATI promoted chromatin structural changes in the nucleus in a kinase activity-dependent manner. We found that expression of ALKATI increased the level of the heterochromatin marker Lys9 tri-methylated histone H3. In addition, we demonstrated that ALKATI phosphorylated the nuclear protein A-kinase anchoring protein 8 (AKAP8) and altered its subcellular localization from the insoluble fraction to the soluble fraction. These results suggest that ALKATI induces chromatin structural changes and heterochromatinization through phosphorylation of AKAP8 in the nucleus.

Overcoming resistance to first/second generation epidermal growth factor receptor tyrosine kinase inhibitors and ALK inhibitors in oncogene-addicted advanced non-small cell lung cancer.

Epidermal growth factor receptor (EGFR) activating mutations and anaplastic lymphoma kinase (ALK) gene rearrangement in advanced non-small cell lung cancer (NSCLC) represent the two oncogenic events with an impact on current clinical practice. EGFR tyrosine kinase inhibitors (TKIs) and crizotinib are the standard of care for the treatment of EGFR mutant and ALK gene rearranged advanced NSCLC patients. Unfortunately, despite initial clinical benefit, acquired resistance to EGFR-TKIs or crizotinib usually develops after an average of 10-12 months of treatment. The aim of this review is to describe the mechanisms of resistance to first/second generation EGFR-TKIs and crizotinib. In particular, we focus on strategies to overcome resistance due to secondary EGFR T790M mutation and mutations of the ALK domain.

Augmentor α and β (FAM150) are ligands of the receptor tyrosine kinases ALK and LTK: Hierarchy and specificity of ligand–receptor interactions

Receptor tyrosine kinases (RTKs) are a class of cell surface receptors that, upon ligand binding, stimulate a variety of critical cellular functions. The orphan receptor anaplastic lymphoma kinase (ALK) is one of very few RTKs that remain without a firmly established protein ligand. Here we present a novel cytokine, FAM150B, which we propose naming augmentor-α (AUG-α), as a ligand for ALK. AUG-α binds ALK with high affinity and activates ALK in cells with subnanomolar potency. Detailed binding experiments using cells expressing ALK or the related receptor leukocyte tyrosine kinase (LTK) demonstrate that AUG-α binds and robustly activates both ALK and LTK. We show that the previously established LTK ligand FAM150A (AUG-β) is specific for LTK and only weakly binds to ALK. Furthermore, expression of AUG-α stimulates transformation of NIH/3T3 cells expressing ALK, induces IL-3 independent growth of Ba/F3 cells expressing ALK, and is expressed in neuroblastoma, a cancer partly driven by ALK. These experiments reveal the hierarchy and specificity of two cytokines as ligands for ALK and LTK and set the stage for elucidating their roles in development and disease states.

Abstract P3-06-39: Anaplastic lymphoma kinase (ALK) protein overexpression is not a feature of inflammatory breast cancer

Abstract Recent studies suggest that anaplastic lymphoma kinase (ALK) could serve as a therapeutic target for inflammatory breast cancer (IBC) and that strategies targeting ALK should be considered for evaluation in clinical trials. Reverse phase protein arays revealed activation of the ALK receptor tyrosine kinase and biochemically-linked downstream signalling molecules in pre-clinical models of IBC. ALK genetic abnormalities have been reported in 80% (20/25) of IBC patients with a high prevalence of ALK alterations in basal-like IBC (Robertson F. et al., 2013). However, ALK protein expression has not been studied in human IBC samples. Immunohistochemical detection of the ALK protein is increasingly being used as a screening tool to test samples for ALK rearrangements. The biological premise is that the genetic abnormality of the ALK gene leads to overexpression of the ALK protein and therefore overactivity of the ALK tyrosine kinase; since this kinase is the target of crizotinib, it makes sense to assess the drug target directly. Formalin fixed paraffin embedded tissue samples from pre-treatment surgical biopsies of 79 consecutive IBC patients were immunohistochemically (IHC) tested for ALK protein over-expression using a validated IHC test (NCL-ALK, clone 5A4) with a sensitivity of 93% and a specificity of 100% when the Vysis ALK-FISH break apart test is used as a gold standard. Stained tissue sections were evaluated using the IHC histoscore proposed by Thunnissen E. et al., 2012, assessing both the proportion of tumor cells showing cytoplasmic staining and the staining intensity. Cytoplasmic staining of appendiceal ganglion cells was used as an on-slide external positive control; weak to moderate cytoplasmic staining of macrophages was used as an internal positive control. In 75 of the 79 tissue samples none of the tumor cells showed any ALK immunoreactivity. One tumor showed moderate cytoplasmic staining in a few cells (<1%, score 2+); ALK (2p23) FISH showed no rearrangement. This tumor was hormone receptor negative and HER2 negative. Three tumors showed minimal cytoplasmic staining in a few cells (<1%, score 1+). These results demonstrate that ALK protein overexpression is not a feature of IBC. Although genetic abnormalities of ALK without protein overexpression are not excluded, our results show that ALK IHC cannot be used to identify IBC patients eligible for enrollment in clinical trials evaluating ALK targeted therapeutics. Citation Format: Cecile Colpaert, Melike Marsan, Peter Vermeulen, Luc Dirix, Steven Van Laere, Inflammatory Breast Cancer International Consortium. Anaplastic lymphoma kinase (ALK) protein overexpression is not a feature of inflammatory breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-06-39.

A ligand for ALK.

The receptor tyrosine kinase ALK (anaplastic lymphoma kinase), as its name suggests, is aberrantly activated, mutated, or abundant in multiple cancers. Although widely studied in the context of cancer, the ligand that normally binds to and activates ALK in vertebrates has remained elusive. In this issue of Science Signaling, Murray and colleagues identify heparin as an ALK ligand.

Anaplastic Lymphoma Kinase (Alk) Positivity in Non Small Cell Lung Cancer (Nsclc) Has Similar or Worse Prognosis for Clinical Outcome As Alk Wild Type: a Systematic Review of Published Literature

ABSTRACT Aim: Anaplastic lymphoma kinase (ALK) positive NSCLC identifies a unique subset of patients who respond to treatment with crizotinib (Pfizer Inc, NY), an ALK receptor tyrosine kinase inhibitor. However, it is not well established whether ALK status is predictive of a better or a worse outcome for those who do not receive crizotinib. We performed a systematic review of recent literature on ALK positive NSCLC to answer this question. Methods: Ovid Medline and Embase databases were searched for publications on ALK-positive NSCLC until December 2013. Studies were included if outcomes for crizotinib naive patients were presented for either Progression-Free Survival (PFS) or Overall Survival (OS). For each study identified, 2 investigators independently extracted and tabulated relevant findings. Demographics, ALK status, type of diagnostic test, treatment received and response to treatment were noted. To determine if ALK status was prognostic, efficacy outcomes (PFS and / or OS) for ALK-positive patients were compared to ALK wild type (WT) patients. Results: Twenty one studies published between 2009 to 2013, with nearly 8000 screened NSCLC patients and 700 ALK-positive patients, met the selection criteria. All publications were retrospective in nature, majority reported single institution experiences, with a mix of completely resected early stage NSCLC and recurrent or advanced disease. The number of ALK-positive patients in studies determined by Fluorescent In Situ Hybridisation (FISH) ranged from 7 to 121 (mean = 32) and the number of ALK-positive patients in studies determined by non-FISH methods ranged from 3 - 39 (mean = 18). Enrichment strategies were commonly employed with predominantly adenocarcinomas being selected for ALK testing. PFS and / or OS for ALK-positive NSCLC patients did not demonstrate a favourable outcome and was similar or worse compared to EGFR WT/ ALK WT patients. Conclusions: This analysis of published retrospective studies in ALK-positive NSCLC, suggest that ALK-positivity is not a positive prognostic factor and does not confer a favourable outcome in absence of crizotinib therapy. Disclosure: J. Binko: Employee of Pfizer Oncology and holder of Pfizer stock; P. Delahoy: Employee of Pfizer Oncology and holder of Pfizer stock. M. Alam: Employee of Pfizer Oncology and holder of Pfizer stock.

Crizotinib in non-small cell lung cancer

Chemotherapy and targeted therapy remain the cornerstone of treatment of locally advanced and metastatic non-small cells lung cancer (NSCLC). Given the intrinsic chemoresistance of tumor cells, new treatment options have been developped. The knowledge of the molecular mechanisms of tumor biology, and signal transduction pathways activating cancer cells led to the identification of a new targeted therapy such as Crizotinib. The small molecule Crizotinib is a selective inhibitor of the receptor tyrosine kinase ALK (anaplastic lymphoma kinase) and its oncogenic variants (ALK fusion gene and some mutations of ALK). Phases I and II trials showed the efficacy of Crizotinib in the treatment of locally advanced and metastatic NSCLC expressing ALK. Thereafter, randomized Phase III trial confirmed the significant superiority of Crizotinib versus standard chemotherapy in terms of progression free survival and objective response with good tolerance; therefore, it has been approved by the Food and Drug Administration (FDA) as the standard treatment for locally advanced and metastatic ALK-positive NSCLC.

Mechanistic insight into ALK receptor tyrosine kinase in human cancer biology

The burgeoning field of anaplastic lymphoma kinase (ALK) in cancer encompasses many cancer types, from very rare cancers to the more prevalent non-small-cell lung cancer (NSCLC). The common activation of ALK has led to the use of the ALK tyrosine kinase inhibitor (TKI) crizotinib in a range of patient populations and to the rapid development of second-generation drugs targeting ALK. In this Review, we discuss our current understanding of ALK function in human cancer and the implications for tumour treatment.

Crizotinib - Molekulare Therapie des Lungenkarzinoms

The anaplastic lymphoma kinase (ALK) can act as a key oncogenic driver after activation by means of processes such as gene rearrangement. In approximately 5 % of patients with advanced non-small cell lung cancer (NSCLC), an oncogenic fusion gene of echinoderm microtubule-associated protein-like 4 (EML4) and ALK has been detected using fluorescence in situ hybridisation (FISH). Moreover, various methods including immunohistochemistry and PCR-based assays can be used for analysing ALK expression. Clinical data have been generated for crizotinib, a small molecule inhibitor of the ALK receptor tyrosine kinase, demonstrating a substantial improvement of objective response rate and prolonged progression-free survival (PFS) compared to standard chemotherapy in pretreated NSCLC patients harbouring EML4-ALK fusion genes. In the current review, recent data on the detection and inhibition of ALK in advanced NSCLC are summarised.