Anaplastic lymphoma kinase: role in cancer pathogenesis and small-molecule inhibitor development for therapy

The synthesis of a novel Crizotinib heptamethine cyanine dye conjugate that potentiates the cytostatic and cytotoxic effects of Crizotinib in patient-derived glioblastoma cell lines

We describe the synthesis of drug-dye conjugate 1 between anaplastic lymphoma kinase inhibitor Crizotinib and heptamethine cyanine dye IR-786. The drug-dye conjugate 1 was evaluated in three different patient-derived glioblastoma cell lines and showed potent cytotoxic activity with nanomolar potency (EC₅₀: 50.9 nM). We also demonstrate evidence for antiproliferative activity of 1 with single digit nanomolar potency (IC₅₀: 4.7 nM). Furthermore, the cytotoxic effects conveyed a dramatic, 110-fold improvement over Crizotinib. This improvement was even more pronounced (492-fold) when 1 was combined with Temozolomide, the standard drug for treatment for glioblastoma. This work lays the foundation for future exploration of similar tyrosine kinase inhibitor drug-dye conjugates for the treatment of glioblastoma.

Profile of alectinib for the treatment of ALK-positive non-small cell lung cancer (NSCLC): patient selection and perspectives

Discovered in 2007, anaplastic lymphoma kinase (ALK) gene rearrangements positive (ALK+) lung cancers compose a small subset of non-small cell lung cancer (NSCLC), with rapidly expanded treatments. There are currently several ALK inhibitors, including crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib which have been licensed by the US Food and Drug Administration or the European Medicines Agency for the treatment of ALK+ NSCLC patients. Along with the multiple therapies, the survival of this subtype of NSCLC has been significantly expanded, even for patients whose disease has spread in the brain. Alectinib (Alecensa), a specific ALK and rearranged during transfection tyrosine kinase inhibitor is approved as first-line therapy for metastatic ALK+ NSCLC patients. It is additionally approved for ALK+ NSCLC previously treated with crizotinib. The main aim of this review is to assemble on the efficacy of alectinib for the treatment of ALK+ NSCLC, to elaborate the activity of the drug in the central nervous system, and to debate on which is the position of this compound in the treatment course of ALK+ lung cancer patients.

Alectinib: A Review in Advanced, ALK-Positive NSCLC

Alectinib (Alecensa^®) is a potent and highly selective anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor. Oral alectinib monotherapy is approved in the EU as first-line treatment for adults with advanced ALK-positive non-small cell lung cancer (NSCLC) and for the treatment of adults with advanced ALK-positive NSCLC previously treated with crizotinib. In the USA, alectinib is indicated for the treatment of adults with ALK-positive metastatic NSCLC. The recommended dosage for alectinib in the EU and USA is 600 mg twice daily. Well-designed phase III studies in patients with ALK-positive NSCLC showed that during up to ≈ 19 months' follow-up, progression-free survival (PFS) was significantly improved with alectinib relative to crizotinib as first-line therapy (ALEX study), and relative to chemotherapy in patients previously treated with crizotinib and platinum-doublet chemotherapy (ALUR study). Central nervous system (CNS)-related outcomes were significantly improved with alectinib in both these settings. Two phase II registrational studies (NP28673 and NP28761) in patients previously treated with crizotinib also demonstrated the efficacy of alectinib, as assessed by objective response rates (ORRs), during up to 21 months' follow-up. Overall, alectinib had a manageable tolerability profile in these settings, with most adverse events (AEs) of mild or moderate severity. Current evidence indicates that alectinib is an important treatment option for patients with advanced ALK-positive NSCLC who are previously untreated or those previously treated with crizotinib. Given its efficacy and tolerability, current guidelines include alectinib as a treatment option in these settings, with the NCCN guidelines recommending it as a preferred option for first-line therapy.

Inhibition of anaplastic lymphoma kinase promotes apoptosis and suppresses proliferation in human hepatocellular carcinoma

Our study was to examine the roles of crizotinib and ceritinib in hepatocellular carcinoma (HCC) cells and explore the possible mechanisms. MTT assay was employed to examine the proliferation of five HCC cell lines treated with various concentrations of crizotinib or ceritinib. HepG2 and HCCLM3 cells were incubated with 2 nmol/l ceritinib for 1 week, followed by crystal violet staining and cell counting. Protein amounts of t-ALK, p-ALK, t-AKT, p-AKT, t-ERK, p-ERK, Mcl-1, survivin, and XIAP in HepG2 cells under different culture conditions were evaluated by western blot. HepG2 and HCCLM3 cells were treated with vehicle or ceritinib and measured by flow cytometry apoptosis analysis with Annexin-V/propidium iodide staining. MTT assay showed that both crizotinib and ceritinib suppressed the proliferation of various human HCC cells. Crystal violet staining analysis also indicated that ceritinib effectively inhibited human HCC cell proliferation. Western blot analysis indicated that both crizotinib and ceritinib inhibited ALK, AKT, and ERK phosphorylations. In addition, ceritinib reduced antiapoptotic gene expressions in HepG2 cells. Flow cytometry analysis indicated that ceritinib induced HepG2 and HCCLM3 cells apoptosis. ALK inhibitor exhibited antitumor effects by inhibiting ALK activation, repressing AKT and ERK pathways, and suppressing antiapoptotic gene expressions, which subsequently promoted apoptosis and suppressed HCC cell proliferations.

Targeting Receptor Kinases in Colorectal Cancer

Colorectal cancer is the third most common malignancy in men and the second most common cancer in women. Despite the success of screening programs and the development of adjuvant therapies, the global burden of colorectal cancer is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In recent years, a great effort has been made to demonstrate the utility of protein kinase inhibitors for cancer treatment. Considering this heterogeneous disease is defined by mutations that activate different Receptor Tyrosine Kinases (RTKs) and affect downstream components of RTK-activated transduction pathways, in this review we analyze the potential utility of different kinase inhibitors for colorectal cancer treatment.

Carcinoma of Unknown Primary with EML4-ALK Fusion Response to ALK Inhibitors

With the advent of next-generation sequencing (NGS) and precision medicine, investigators have determined that tumors from different tissue sources that have the same types of genetic mutations will have a positive response to the same targeted therapy. This finding has prompted us to seek potential therapeutic targets for patients with carcinoma of unknown primary (CUP) using NGS technology. Here, we reported a case of a woman with CUP resistance to chemotherapy. We detected 450 cancer-related gene alterations using three metastatic tumor specimens and found the presence of EML4 exon13 and ALK exon20 fusion. The tumor did respond to crizotinib, a first-generation ALK inhibitor. When her tumor progressed, circulating tumor DNA detection revealed ALK L1196 M and G1269A mutation resistance to crizotinib, but she had a response to brigatinib. This case revealed that NGS technology used to detect the genetic alterations in patients with CUP might be a reliable method to find potential therapeutic targets, although the primary lesion could not always be confirmed. KEY POINTS: This case exemplifies responsiveness to ALK inhibitor in carcinoma of unknown primary (CUP) with EML4-ALK fusion.Next-generation sequencing is an important diagnostic tool to find potential therapeutic targets in CUP.Liquid biopsy may be useful to provide critical information about resistance mechanisms in CUP to guide sequential treatment decision with targeted therapy.

A comprehensive review on Brigatinib - A wonder drug for targeted cancer therapy in non-small cell lung cancer

The mortality rate in patients suffering from non-small cell lung cancer (NSCLC) is quite high. This type of cancer mainly occurs due to rearrangements in the anaplastic lymphoma kinase (ALK) gene which leads to form an oncogene of fused gene NPM-ALK. Brigatinib is recently approved by FDA in April 2017 as a potent tyrosine kinase inhibitor (TKI) for the NSCLC therapy. In the present scenario, it is no less than a wonder drug because it is indicated for the treatment of advanced stages of metastatic ALK positive NSCLC, a fatal disease to overcome the resistance of various other ALK inhibitors such as crizotinib, ceritinib and alectinib. In addition to ALK, it is also active against multiple types of kinases such as ROS1, Insulin like growth factor-1Receptor and EGFR. It can be synthesized by using N-[2-methoxy-4-[4-(dimethylamino) piperidin-1-yl] aniline] guanidine and 2,4,5-trichloropyrimidine respectively in two different ways. Its structure consists of mainly dimethylphosphine oxide group which is responsible for its pharmacological activity. It is active against various cell lines such as HCC78, H2228, H23, H358, H838, U937, HepG2 and Karpas- 299. Results of ALTA (ALK in Lung Cancer Trial of AP26113) phase ½ trial shows that 90 mg of brigatinib for 7 days and then 180 mg for next days is effective in the treatment of NSCLC. Brigatinib has been shown to have favorable risk benefit profile and is a safer drug than the available cytotoxic chemotherapeutic agents. In comparison to other FDA approved drugs for the same condition, it causes fewer minor adverse reactions which can be easily managed either by changing the dose or by providing good supportive care. This article is intended to provide readers with an overview of chemistry, pharmacokinetic, pharmacodynamic and safety profile of brigatinib, which addresses an unmet medical need.

Crizotinib induces apoptosis and gene expression changes in ALK+ anaplastic large cell lymphoma cell lines; brentuximab synergizes and doxorubicin antagonizes

BACKGROUND

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) shows 60-70% event free survival with standard treatments. Targeted therapies are being tested for increased benefit and/or reduced toxicity, but interactions with standard agents are not well known.

METHODS

We exposed four ALCL cell lines to two targeted agents, crizotinib and brentuximab vedotin, and to two standard agents, doxorubicin and vinblastine. For each agent and combination, we measured apoptosis and expression of approximately 300 previously annotated genes of interest using targeted RNA-sequencing. An aurora kinase inhibitor, alisertib, was similarly tested for gene expression effects.

RESULTS

Only crizotinib, alone or in combination, showed significant effects (adjusted P < 0.05) on expression and apoptosis. One hundred and nine of 277 gene expressions showed crizotinib-associated differential expression, mostly downregulation, 62 associated with apoptosis, and 28 associated with both crizotinib and apoptosis. Doxorubicin was antagonistic with crizotinib on gene expression and apoptosis. Brentuximab was synergistic with crizotinib in apoptosis, and not antagonistic in gene expression. Vinblastine also appeared synergistic with crizotinib but did not achieve statistical significance. Alisertib did not show significant expression changes.

CONCLUSIONS

Our data suggest that crizotinib induces apoptosis through orderly changes in cell signaling associated with ALK inhibition. Expression effects of crizotinib and associated apoptosis are antagonized by doxorubicin, but apoptosis is synergized by brentuximab vedotin and possibly vinblastine. These findings suggest that concurrent use of crizotinib and doxorubicin may be counterproductive, while the pairing of crizotinib with brentuximab (or vinblastine) may increase efficacy. Alisertib did not induce expression changes at cytotoxic dosage.

Inflammatory myofibroblastic tumors-A retrospective analysis of the Cooperative Weichteilsarkom Studiengruppe

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) are a rare subgroup of soft tissue tumors. The outcome of patients with IMT has been reported as favorable when the tumor is completely resected. If surgical resection is not possible, systemic therapy has to be considered. However, the best systemic treatment and response rates are currently unclear.

METHODS

Thirty-eight patients under the age of 21, who were registered between 2000 and 2014 with a primary diagnosis of IMT, were analyzed.

RESULTS

IMT was typically localized intra-abdominally or in the pelvis. In 20 patients, the tumor was resected without further therapy; 17 patients were in complete remission at last evaluation and two patients were in partial remission. Eighteen patients received systemic therapy, 15 of whom had macroscopically incomplete resection. Systemic therapy most commonly consisted of regimens with dactinomycin, ifosfamide or cyclophosphamide, and vincristine, with or without doxorubicin, and it seemed to reduce tumor extension in individual cases. Five-year event-free survival was 74 ± 14% and 5-year overall survival was 91 ± 10% for all patients. The patients who died due to the disease were those with incomplete resection (n = 3).

CONCLUSIONS

Surgery without further systemic therapy was a feasible and acceptable therapeutic option for every second patient with IMT. Standard chemotherapy for pediatric soft tissue sarcoma produced favorable results in individual cases and was able to shrink the tumor enough to enable resection. Superior efficacy of new targeted therapies such as anaplastic lymphoma kinase-inhibitors compared to standard chemotherapy has to be proven in the future.

Phosphoproteomics reveals ALK promote cell progress via RAS/ JNK pathway in neuroblastoma

Emerging evidence suggests receptor tyrosine kinase ALK as a promising therapeutic target in neuroblastoma. However, clinical trials reveal that a limited proportion of ALK-positive neuroblastoma patients experience clinical benefits from Crizotinib, a clinically approved specific inhibitor of ALK. The precise molecular mechanisms of aberrant ALK activity in neuroblastoma remain elusive, limiting the clinical application of ALK as a therapeutic target in neuroblastoma. Here, we describe a deep quantitative phosphoproteomic approach in which Crizotinib-treated neuroblastoma cell lines bearing aberrant ALK are used to investigate downstream regulated phosphoproteins. We identified more than 19,500-and quantitatively analyzed approximately 10,000-phosphorylation sites from each cell line, ultimately detecting 450-790 significantly-regulated phosphorylation sites. Multiple layers of bioinformatic analysis of the significantly-regulated phosphoproteins identified RAS/JNK as a downstream signaling pathway of ALK, independent of the ALK variant present. Further experiments demonstrated that ALK/JNK signaling could be inactivated by either ALK- or JNK-specific inhibitors, resulting in cell growth inhibition by induction of cell cycle arrest and cell apoptosis. Our study broadly defines the phosphoproteome in response to ALK inhibition and provides a resource for further clinical investigation of ALK as therapeutic target for the treatment of neuroblastoma.

TKI sensitivity patterns of novel kinase-domain mutations suggest therapeutic opportunities for patients with resistant ALK+ tumors

The anaplastic lymphoma kinase (ALK) protein drives tumorigenesis in subsets of several tumors through chromosomal rearrangements that express and activate its C-terminal kinase domain. In addition, germline predisposition alleles and acquired mutations are found in the full-length protein in the pediatric tumor neuroblastoma. ALK-specific tyrosine kinase inhibitors (TKIs) have become important new drugs for ALK-driven lung cancer, but acquired resistance via multiple mechanisms including kinase-domain mutations eventually develops, limiting median progression-free survival to less than a year. Here we assess the impact of several kinase-domain mutations that arose during TKI resistance selections of ALK+ anaplastic large-cell lymphoma (ALCL) cell lines. These include novel variants with respect to ALK-fusion cancers, R1192P and T1151M, and with respect to ALCL, F1174L and I1171S. We assess the effects of these mutations on the activity of six clinical inhibitors in independent systems engineered to depend on either the ALCL fusion kinase NPM-ALK or the lung-cancer fusion kinase EML4-ALK. Our results inform treatment strategies with a likelihood of bypassing mutations when detected in resistant patient samples and highlight differences between the effects of particular mutations on the two ALK fusions.

Oncogene addiction and radiation oncology: effect of radiotherapy with photons and carbon ions in ALK-EML4 translocated NSCLC

Background

Patients with Echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) positive lung cancer are sensitive to ALK-kinase inhibitors. TAE684 is a potent second generation ALK inhibitor that overcomes Crizotinib resistance. Radiotherapy is an integral therapeutic component of locally advanced lung cancer. Therefore, we sought to investigate the effects of combined radiotherapy and ALK-inhibition via TAE684 in ALK-positive vs. wild type lung cancer cells.

Methods

Human non-small cell lung cancer (NSCLC) cell lines harboring wild-type ALK (A549), EML4-ALK translocation (H3122) and murine Lewis Lung Cancer (LLC) cells were investigated. Cells were irradiated with 1–4 Gy X-Rays (320 keV) and carbon ions (Spread-out Bragg Peak, SOBP (245.4–257.0 MeV/u)) at Heidelberg Ion Therapy center. TAE684 was administered at the dose range 0–100 nM. Clonogenic survival, proliferation and apoptosis via caspase 3/7 expression level were assessed in all three cell lines using time-lapse live microscopy.

Results

TAE684 inhibited the proliferation of H3122 cells in a dose-dependent manner with a half maximal inhibitory concentration (IC₅₀) of ~ 8.2 nM. However, A549 and LLC cells were relatively resistant to TAE684 and IC₅₀ was not reached at concentrations tested (up to 100 nM) in proliferation assay. The antiproliferative effect of TAE684 was augmented by radiotherapy in H3122 cells. TAE684 significantly sensitized H3122 cells to particle therapy with carbon ions (sensitizer enhancement ratio ~1.61, p < 0.05). Caspase 3/7 activity was evidently enhanced after combination therapy in H3122 cells.

Conclusions

This is the first report demonstrating synergistic effects of combined TAE684 and radiotherapy in EML4-ALK positive lung cancer cells. In addition to conventional photon radiotherapy, ALK-inhibition also enhanced the effects of particle irradiation using carbon ions. Our data indicate beneficial effects of combined ALK-inhibition and radiotherapy in treatment of this distinct subpopulation of NSCLC that warrant further evaluation.

Alectinib

Alectinib is an ATP-competitive small molecule and a second-generation inhibitor of ALK. EML4-ALK rearrangement is found in 3-5% of patients with NSCLC. The first-generation inhibitor crizotinib has changed the treatment dramatically, though most of the patients show disease progression within one year. Extra-thoracic progress, i.e., CNS metastases is common. The second-generation inhibitor alectinib has shown significant improvement in PFS and a remarkable prolongation of time to CNS progression. Alectinib has received approval as first-line therapy as well as second-line therapy after crizotinib failure. The toxicity profile is favorable compared to crizotinib and chemotherapy.

Heterogeneous distribution of alectinib in neuroblastoma xenografts revealed by matrix-assisted laser desorption ionization mass spectrometry imaging: a pilot study

BACKGROUND AND PURPOSE

The penetration of the anaplastic lymphoma kinase (ALK) inhibitor alectinib in neuroblastomas and the relationship between alectinib and ALK expression are unknown. The aim of this study was to perform a quantitative investigation of the inter- and intra-tumoural distribution of alectinib in different neuroblastoma xenograft models using matrix-assisted laser desorption ionization MS imaging (MALDI-MSI).

EXPERIMENTAL APPROACH

The distribution of alectinib in NB1 (ALK amplification) and SK-N-FI (ALK wild-type) xenograft tissues was analysed using MALDI-MSI. The abundance of alectinib in tumours and intra-tumoural areas was quantified using ion signal intensities from MALDI-MSI after normalization by correlation with LC-MS/MS.

KEY RESULTS

The distribution of alectinib was heterogeneous in neuroblastomas. The penetration of alectinib was not significantly different between ALK amplification and ALK wide-type tissues using both LC-MS/MS concentrations and MSI intensities. Normalization with an internal standard increased the quantitative property of MSI by adjusting for the ion suppression effect. The distribution of alectinib in different intra-tumoural areas can alternatively be quantified from MS images by correlation with LC-MS/MS.

CONCLUSION AND IMPLICATIONS

The penetration of alectinib into tumour tissues may not be homogenous or influenced by ALK expression in the early period after single-dose administration. MALDI-MSI may prove to be a valuable pharmaceutical method for elucidating the mechanism of action of drugs by clarifying their microscopic distribution in heterogeneous tissues.

A genome-wide microRNA profiling indicates miR-424-5p and miR-503-5p as regulators of ALK expression in neuroblastoma

The discovery of missense mutations of ALK gene identified this receptor tyrosine kinase as a therapeutic target in neuroblastoma (NB). Moreover, a high level of ALK protein has been associated with metastatic NB cases and with a worse prognosis, suggesting that also ALK overexpression is involved in NB tumorigenesis. Since miRNAs play key roles in the regulation of gene expression we aimed at identifying those miRNAs that can regulate ALK in NB. We therefore analyzed the genome-wide expression profile of miRNAs in two sample sets of 16 NB cell lines and 22 NB samples by using miRNA microarrays. Both sample sets were then divided into two subgroups showing high (ALK+) or low/absent (ALK-) expression of ALK. Results showed a down-regulation of 30 and 23 miRNAs (p-value <0.05) in the ALK+ group in NB cell lines and samples, respectively. Validation analysis indicated that miR-424-5p and miR-503-5p, belonging to the same cluster, were differentially expressed in both NB cell lines and tumor samples. Although only miR-424-5p showed a direct binding to ALK 3′-UTR, both miRNAs led to a remarkable decreasing of ALK protein as well as to the inhibition of cell viability in ALK+ NB cell lines. In conclusion, our data indicate that both miR-424-5p and miR-503-5p are involved in regulating ALK expression in NB, either by directly targeting ALK receptor or indirectly, and may thus serve as potential therapeutic tools in ALK dependent NBs.

Lymphoma classification update: T-cell lymphomas, Hodgkin lymphomas, and histiocytic/dendritic cell neoplasms

INTRODUCTION

Lymphomas are classified based on the normal counterpart, or cell of origin, from which they arise. Because lymphocytes have physiologic immune functions that vary both by lineage and by stage of differentiation, the classification of lymphomas arising from these normal lymphoid populations is complex. Recent genomic data have contributed additional depth to this complexity. Areas covered: Lymphoma classification follows the World Health Organization (WHO) system, which reflects international consensus and is based on pathological, genetic, and clinical factors. The present review focuses on the classification of T-cell lymphomas, Hodgkin lymphomas, and histiocytic and dendritic cell neoplasms, summarizing changes reflected in the 2016 revision to the WHO classification. These changes are critical to hematologists and other clinicians who care for patients with these disorders. Expert commentary: Lymphoma classification is a continually evolving field that needs to be responsive to new clinical, pathological, and molecular understanding of lymphoid neoplasia. Among the entities covered in this review, the 2016 revisions in the WHO classification particularly impact T-cell lymphomas, including a new umbrella category of T-follicular helper cell-derived lymphomas and evolving recognition of indolent T-cell lymphomas and lymphoproliferative disorders.

Treating patients with ALK-rearranged non-small-cell lung cancer: mechanisms of resistance and strategies to overcome it

Anaplastic lymphoma kinase (ALK) rearrangement is detected in 3-7% of patients with non-small-cell lung cancer. Crizotinib is an ALK inhibitor, which was approved in 2011 for the treatment of ALK-positive lung cancer. Despite the initial enthusiasm, most of the patients develop resistance within the first year of treatment. The main mechanisms are secondary mutations and bypass track activation. Moreover, crizotinib has low penetration into the central nervous system. The need to overcome these limitations has led to the development of second-generation inhibitors that have better effectiveness against crizotinib-resistant mutations and brain metastases. Ceritinib and alectinib are the only approved drugs of this group. Many ongoing trials try to define the most appropriate agent for the treatment of ALK-positive lung cancer depending on the responsible mechanism. This review focuses on the current data regarding the potential mechanisms of resistance to ALK inhibitors and the strategies to overcome it.

ALK: a tyrosine kinase target for cancer therapy

The anaplastic lymphoma kinase (ALK) gene plays an important physiologic role in the development of the brain and can be oncogenically altered in several malignancies, including non-small-cell lung cancer (NSCLC) and anaplastic large cell lymphomas (ALCL). Most prevalent ALK alterations are chromosomal rearrangements resulting in fusion genes, as seen in ALCL and NSCLC. In other tumors, ALK copy-number gains and activating ALK mutations have been described. Dramatic and often prolonged responses are seen in patients with ALK alterations when treated with ALK inhibitors. Three of these—crizotinib, ceritinib, and alectinib—are now FDA approved for the treatment of metastatic NSCLC positive for ALK fusions. However, the emergence of resistance is universal. Newer ALK inhibitors and other targeting strategies are being developed to counteract the newly emergent mechanism(s) of ALK inhibitor resistance. This review outlines the recent developments in our understanding and treatment of tumors with ALK alterations.

Mutation L1196M-induced conformational changes and the drug resistant mechanism of anaplastic lymphoma kinase studied by free energy perturbation and umbrella sampling

Anaplastic lymphoma kinase (ALK) has been regarded as a promising drug target in the treatment of tumors and the mutation L1196M induces different levels of drug resistance toward the existing inhibitors.

Anaplastic lymphoma kinase: Role in cancer and therapy perspective

Anaplastic lymphoma kinase (ALK) is correlated with oncogenesis in different types of cancers, such as anaplastic large cell lymphoma, lung cancer, neuroblastoma, and even breast cancer, by abnormal fusion of ALK or non-fusion ALK activation. ALK is a receptor tyrosine kinase, with a single transmembrane domain, that plays an important role in development. Upon ligand binding to the extracellular domain, the receptor undergoes dimerization and subsequent autophosphorylation of the intracellular kinase domain. In recent years, ALK inhibitors have been developed for cancer treatment. These inhibitors target ALK activity and show effectiveness in ALK-positive non-small cell lung cancer. However, acquired treatment resistance makes the future of this therapy unclear; new strategies are underway to overcome the limitations of current ALK inhibitors.

Brain Metastases from NSCLC: Radiation Therapy in the Era of Targeted Therapies

Brain metastases (BMs) will develop in a large proportion of patients with NSCLC throughout the course of their disease. Among patients with NSCLC with oncogenic drivers, mainly EGFR activating mutations and anaplastic lymphoma receptor tyrosine kinase gene (ALK) rearrangements, the presence of BM is a common secondary localization of disease both at the time of diagnosis and at relapse. Because of the limited penetration of a wide range of drugs across the blood-brain barrier, radiotherapy is considered the cornerstone of treatment of BMs. However, evidence of dramatic intracranial response rates has been reported in recent years with targeted therapies such as tyrosine kinase inhibitors and has been supported by new insights into pharmacokinetics to increase rates of tyrosine kinase inhibitors' penetration of the cerebrospinal fluid (CSF). In this context, the combination of brain radiotherapy and targeted therapies seems relevant, and there is a strong radiobiological rationale to harness the radiosentizing effect of the drugs. Nevertheless, to date, there is a paucity of high-level clinical evidence supporting the combination of brain radiotherapy and targeted therapies in patients with NSCLC and BMs, and there are often methodological biases in reported studies, such as the lack of stratification by mutation status. Moreover, among asymptomatic patients not suitable for ablative treatment, this strategy is challenged by the promising results associated with the administration of targeted therapies alone. Herein, we review the biological rationale to combine targeted therapies and brain radiotherapy for patients with NSCLC and BMs, report the clinical data available to date, and discuss future directions to improve outcome in this group of patients.

[Radiotherapy and targeted therapy/immunotherapy]

Thanks to recent advances achieved in oncologic systemic and local ablative treatment, the treatments become more and more efficient in term of local control and overall survival. Thus, the targeted therapies, immunotherapy or stereotactic radiotherapy have modified the management of patients, especially in case of oligometastatic disease. Many questions are raised by these innovations, particularly the diagnosis and management of new side effects or that of the combination of these different treatments, depending on the type of primary tumor. Fundamental data are available, while clinical data are still limited. Ongoing trials should help to clarify the clinical management protocols. This manuscript is a review of the combination of radiotherapy and targeted therapy/immunotherapy.

Atractylodin Inhibits Interleukin-6 by Blocking NPM-ALK Activation and MAPKs in HMC-1

Atractylodin is one of the major constituents of the rhizome of Atractylodes lancea, which is widely used in Korean traditional medicine as a remedy for the treatment of gastritis and gastric ulcers. Despite of a major constituent of widely used botanical to treat inflammatory responses little is known about anti-inflammatory effect of atractylodin in the human mast cell (HMC-1). Hence, we evaluated the effect of atractylodin on the release of IL-6, the involvement of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) and mitogen-activated protein kinases (MAPKs) in phorbol-12-myristate-13-acetate and A23187-induced HMC-1. In addition, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), phospholipase C (PLC) gamma 1, and AKT phosphorylation relevant to NPM-ALK signal pathway were assessed. IL-6 levels in the HMC-1 stimulated by phorbol-12-myristate-13-acetate and A23187 were apparently decreased by the treatment of atractylodin. Concurrently, atractylodin not only inhibited the phosphorylation of NPM-ALK, but also suppressed the phosphorylation of JAK2, STAT3, PLC gamma 1, and AKT. Furthermore, the activated mitogen-activated protein kinases (MAPKs) by phorbol-12-myristate-13-acetate and A23187 were inhibited by atractylodin. These results suggested that atractylodin might have a potential regulatory effect on inflammatory mediator expression through blockade of both the phosphorylation of MAPKs and the NPM-ALK signaling pathway.

Co-targeting ALK and EGFR parallel signaling in oral squamous cell carcinoma

Squamous cell carcinoma (SCC) comprises 90% of all head and neck cancers and has a poor survival rate due to late-stage disease that is refractive to traditional therapies. Epidermal growth factor receptor (EGFR) is over-expressed in greater than 80% of head and neck SCC (HNSCC). However, EGFR targeted therapies yielded little to no efficacy in clinical trials. This study investigated the efficacy of co-targeting EGFR and the anaplastic lymphoma kinase (ALK) whose promoter is hypomethylated in late-stage oral SCC (OSCC). We observed increased ALK activity in late-stage human OSCC tumors and invasive OSCC cell lines. We also found that while ALK inhibition alone had little effect on proliferation, co-targeting ALK and EGFR significantly reduced OSCC cell proliferation in vitro. Further analysis showed significant efficacy of combined treatment in HSC3-derived xenografts resulting in a 30% decrease in tumor volumes by 14days (p<0.001). Western blot analysis showed that co-targeting ALK and EGFR significantly reduced EGFR phosphorylation (Y1148) in HSC3 cells but not Cal27 cells. ALK and EGFR downstream signaling interactions are also demonstrated by Western blot analysis in which lone EGFR and ALK inhibitors attenuated AKT activity whereas co-targeting ALK and EGFR completely abolished AKT activation. No effects were observed on ERK1/2 activation. STAT3 activity was significantly induced by lone ALK inhibition in HSC3 cells and to a lower extent in Cal27 cells. Together, these data illustrate that ALK inhibitors enhance anti-tumor activity of EGFR inhibitors in susceptible tumors that display increased ALK expression, most likely through abolition of AKT activation.

Acquired Resistance to Clinical Cancer Therapy: A Twist in Physiological Signaling

Although modern therapeutic strategies have brought significant progress to cancer care in the last 30 years, drug resistance to targeted monotherapies has emerged as a major challenge. Aberrant regulation of multiple physiological signaling pathways indispensable for developmental and metabolic homeostasis, such as hyperactivation of pro-survival signaling axes, loss of suppressive regulations, and impaired functionalities of the immune system, have been extensively investigated aiming to understand the diversity of molecular mechanisms that underlie cancer development and progression. In this review, we intend to discuss the molecular mechanisms of how conventional physiological signal transduction confers to acquired drug resistance in cancer patients. We will particularly focus on protooncogenic receptor kinase inhibition-elicited tumor cell adaptation through two major core downstream signaling cascades, the PI3K/Akt and MAPK pathways. These pathways are crucial for cell growth and differentiation and are frequently hyperactivated during tumorigenesis. In addition, we also emphasize the emerging roles of the deregulated host immune system that may actively promote cancer progression and attenuate immunosurveillance in cancer therapies. Understanding these mechanisms may help to develop more effective therapeutic strategies that are able to keep the tumor in check and even possibly turn cancer into a chronic disease.

Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase

In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

Second- and third-generation ALK inhibitors for non-small cell lung cancer

Crizotinib as the first-generation ALK inhibitor has shown significant activity in ALK-mutated non-small cell lung cancer (NSCLC). Second- and third-generation ALK inhibitors are entering clinical applications for ALK+ NSCLC. In addition, a third-generation ALK inhibitor, lorlatinib (PF-06463922), was reported to resensitize NSCLC to crizotinib. This review provided a summary of clinical development of alectinib, ceritinib, brigatinib (AP26113), and lorlatinib.

Targeted immunotherapy for pediatric solid tumors

Metastatic and refractory pediatric solid tumor malignancies continue to have a poor outcome despite the > 80% cure rates appreciated in many pediatric cancers. Targeted immunotherapy is impacting treatment and survival in these aggressive tumors. We review current promising immunotherapeutic approaches in the pediatric oncology solid tumor setting.

Anaplastic lymphoma kinase protein expression predicts micrometastases and prognosis for patients with hepatocellular carcinoma

The present study aimed to investigate anaplastic lymphoma kinase (ALK) status in hepatocellular carcinoma (HCC) and to evaluate whether abnormalities in expression were associated with patient prognosis. ALK status was investigated using immunohistochemistry (IHC), reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and fluorescence in situ hybridization (FISH) assays in 342 HCC patients. In addition, rapid amplification of complementary DNA ends-coupled PCR sequencing was performed, in order to confirm the presence of ALK abnormalities in patients exhibiting ALK messenger RNA (mRNA) overexpression. The correlation between ALK expression and the clinicopathological features and prognosis of the HCC patients was statistically analyzed. The results of the present study revealed overexpression of ALK protein and mRNA; furthermore, ALK gene copy number gains were observed via IHC (44.7%; 153/342), RT-qPCR (47.4%; 162/342) and FISH (32.7%; 112/342) analyses, although ALK rearrangement or mutation was not demonstrated in the results of any of these assays. ALK protein expression levels were significantly associated with hepatitis C virus (HCV) status (P<0.001) and the presence of micrometastases (P=0.011). Within the entire patient cohort, ALK expression was associated with poor progression-free survival (PFS; P=0.041). Subsequent analysis in patient subgroups that demonstrated hepatitis B surface antigen positivity, HCV negativity, stage III-IV disease, recurrence and micrometastasis positivity revealed that overall survival (OS) and PFS were significantly reduced in those patients exhibiting ALK expression compared with those patients who were negative for ALK expression. Multivariate analysis revealed that ALK expression was an independent risk factor for OS (P=0.042) and PFS (P=0.033), particularly for patients with stage III-IV tumors. Thus, ALK may serve as a novel indicator for the metastatic behavior and prognosis of HCC.

Intact or broken-apart RNA: an alternative concept for ALK fusion screening in non-small cell lung cancer (NSCLC)

Anaplastic lymphoma kinase (ALK) break-apart fluorescent in situ hybridization (FISH) is currently used in diagnostics for the selection of non-small cell lung cancer (NSCLC) patients to receive crizotinib. We evaluated ALK status in NSCLC with a novel ALK mRNA test based on the break-apart FISH concept, which we called break-apart transcript (BAT) test. ALK5' and ALK3' transcript patterns were established with qPCR for ALK-expressing controls including fusion-negative neuroblastomas, as well as fusion-positive anaplastic large cell lymphomas and NSCLC. The BAT test was evaluated on 271 RNA samples from routinely processed paraffin NSCLC tissues. Test results were compared with ALK FISH (n=121), immunohistochemical (IHC) analysis (n=86), and automated quantitative analysis (AQUA, n=83). On the basis of the nonoverlapping ALK BAT patterns in ALK-expressing controls (P<0.0001), 8/174 adenocarcinomas (4.6%) among 259 informative NSCLC were predicted as fusion positive. Overall concordance for paired method results was high (94.1% to 98.8%) but mainly concerned negative prediction because of the limited availability of positive-matched cases. Tumors with 100% cytoplasmic IHC staining of any intensity (n=3) were positive for AQUA, FISH, and BAT test; tumors with lower IHC positivity and different staining patterns were AQUA-negative. Upon multiple reevaluations, ALK gene status was considered as originally misinterpreted by FISH in 3/121 cases (2.5%). Tumors with >4 ALK gene copies were associated with longer overall survival upon first-line chemotherapy. In conclusion, application of the ALK BAT test on routinely processed NSCLC tissues yields the same fusion partner independent information as ALK break-apart FISH but is more robust and cost-effective. The BAT concept may be considered for the development of further drug-predictive translocation tests.

Chemoresistance, cancer stem cells, and miRNA influences: the case for neuroblastoma

Neuroblastoma is a type of cancer that develops most often in infants and children under the age of five years. Neuroblastoma originates within the peripheral sympathetic ganglia, with 30% of the cases developing within the adrenal medulla, although it can also occur within other regions of the body such as nerve tissue in the spinal cord, neck, chest, abdomen, and pelvis. MicroRNAs (miRNAs) regulate cellular pathways, differentiation, apoptosis, and stem cell maintenance. Such miRNAs regulate genes involved in cellular processes. Consequently, they are implicated in the regulation of a spectrum of signaling pathways within the cell. In essence, the role of miRNAs in the development of cancer is of utmost importance for the understanding of dysfunctional cellular pathways that lead to the conversion of normal cells into cancer cells. This review focuses on highlighting the recent, important implications of miRNAs within the context of neuroblastoma basic research efforts, particularly concerning miRNA influences on cancer stem cell pathology and chemoresistance pathology for this condition, together with development of translational medicine approaches for novel diagnostic tools and therapies for this neuroblastoma.

ALK and ROS1 as a joint target for the treatment of lung cancer: a review

Rearrangements of the anaplastic lymphoma kinase (ALK) have been described in multiple malignancies, including non-small cell lung cancer (NSCLC). ALK fusions have gain of function properties while activating mutations in wild-type ALK can also occur within the tyrosine kinase domain. ALK rearrangements define a new molecular subtype of NSCLC that is exquisitely sensitive to ALK inhibition. Crizotinib, an orally available small molecule ATP-mimetic compound which was originally designed as a MET inhibitor, was recognized to have "off-target" anti-ALK activity and has been approved in the USA for the treatment of patients with ALK-positive NSCLC. Chromosomal rearrangements involving the ROS1 receptor tyrosine kinase have also been recently described in NSCLC, while crizotinib is currently under clinical trial in this molecular subset of NSCLC patients. The basic approaches of any computer aided drug design work in terms of structure and ligand based drug design. Details of each of these approaches should be covered with an emphasis on utilizing both in order to develop multi-targeted small-molecule kinase inhibitors. Such multi-targeted tyrosine kinase inhibitors can have antiproliferative activity against both ROS1and ALK rearranged NSCLC. Herein, we highlight the importance of targeting these proteins and the advances in optimizing more potent and selective ALK and ROS1 kinase inhibitors.

The Clinicopathologic Features and Prognostic Impact of ALK Positivity in Patients with Resected Gastric Cancer

BACKGROUND

Rearrangement of ALK is an established driver aberration in lung cancer. Accordingly, this study attempted to determine the frequency and prognostic impact of ALK alterations in patients with surgically resected gastric cancer.

METHODS

The study evaluated ALK alterations in whole tumor sections of 455 curatively resected gastric cancers via immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). Any expression of ALK protein (1+, 2+, 3+ by IHC) was considered as evidence of ALK positivity (ALK+), and the relationship between ALK positivity and clinicopathologic parameters, including survival outcome, was analyzed.

RESULTS

Of the 455 tumors, 38 (8.4 %) were ALK positive, as measured by IHC. Among the ALK+ patients, two displayed break-apart signals of 5 and 11 % on FISH, respectively. The ALK+ patients were younger (57 vs. 61 years; P = 0.02) and more likely to exhibit a signet ring cell component. Moreover, as ALK intensity measured by IHC increased, so did the proportion of signet ring cells in tumors (defined as ≥10 % of tumor cells; P = 0.02). In terms of survival outcome, the ALK+ patients displayed worse disease-free survival (DFS) and overall survival (OS) than the ALK- patients (P = 0.010 for DFS; P = 0.023 for OS). Multivariate analysis demonstrated that ALK+ gastric cancer patients were at an increased risk of recurrence and death after adjustment for sex, age, tumor location, stage, adjuvant chemotherapy, histology, and epidermal growth factor receptor 2 (HER2) positivity (P = 0.04 for DFS; P = 0.02 for OS).

CONCLUSIONS

The findings showed ALK positivity to be an independent negative prognostic factor in surgically resected gastric cancers associated with signet ring cell histology.

SEC31A-ALK Fusion Gene in Lung Adenocarcinoma

Anaplastic lymphoma kinase (ALK) fusion is a common mechanism underlying pathogenesis of non-small cell lung carcinoma (NSCLC) where these rearrangements represent important diagnostic and therapeutic targets. In this study, we found a new ALK fusion gene, SEC31A-ALK, in lung carcinoma from a 53-year-old Korean man. The conjoined region in the fusion transcript was generated by the fusion of SEC31A exon 21 and ALK exon 20 by genomic rearrangement, which contributed to generation of an intact, in-frame open reading frame. SEC31A-ALK encodes a predicted fusion protein of 1,438 amino acids comprising the WD40 domain of SEC31A at the N-terminus and ALK kinase domain at the C-terminus. Fluorescence in situ hybridization studies suggested that SEC31A-ALK was generated by an unbalanced genomic rearrangement associated with loss of the 3'-end of SEC31A. This is the first report of SEC31A-ALK fusion transcript in clinical NSCLC, which could be a novel diagnostic and therapeutic target for patients with NSCLC.

Advances in understanding the pathogenesis of systemic anaplastic large cell lymphomas

The currently used 2008 World Health Organization classification recognizes two types of systemic anaplastic large T cell lymphoma according to ALK protein expression in tumour cells. First, the 'anaplastic large cell lymphoma, ALK positive' (ALK(+) ALCL) that is characterized by the presence of ALK gene rearrangements and consequent ALK protein expression, and, second, the 'anaplastic large cell lymphoma, ALK negative' (ALK(-) ALCL) that is a provisional entity lacking ALK protein expression but cannot be distinguished morphologically from ALK(+) ALCL. In this review we summarize the current knowledge on the genetic lesions and biological features that underlie the pathogenesis of ALK(+) and the ALK(-) ALCL and that can lead to the use of targeted anti-cancer agents.

Anaplastic large cell lymphomas: ALK positive, ALK negative, and primary cutaneous

Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.

Micro-cost Analysis of ALK Rearrangement Testing by FISH to Determine Eligibility for Crizotinib Therapy in NSCLC: Implications for Cost Effectiveness of Testing and Treatment

Break-apart fluorescence in situ hybridization (FISH) is the gold standard test for anaplastic lymphoma kinase (ALK) gene rearrangement. However, this methodology often is assumed to be expensive and potentially cost-prohibitive given the low prevalence of ALK-positive non-small cell lung cancer (NSCLC) cases. To more accurately estimate the cost of ALK testing by FISH, we developed a micro-cost model that accounts for all cost elements of the assay, including laboratory reagents, supplies, capital equipment, technical and pathologist labor, and the acquisition cost of the commercial test and associated reagent kits and controls. By applying a set of real-world base-case parameter values, we determined that the cost of a single ALK break-apart FISH test result is $278.01. Sensitivity analysis on the parameters of batch size, testing efficiency, and the cost of the commercial diagnostic testing products revealed that the cost per result is highly sensitive to batch size, but much less so to efficiency or product cost. This implies that ALK testing by FISH will be most cost effective when performed in high-volume centers. Our results indicate that testing cost may not be the primary determinant of crizotinib (Xalkori^®) treatment cost effectiveness, and suggest that testing cost is an insufficient reason to limit the use of FISH testing for ALK rearrangement.

Identification of novel tumor-associated cell surface sialoglycoproteins in human glioblastoma tumors using quantitative proteomics

Glioblastoma multiform (GBM) remains clinical indication with significant “unmet medical need”. Innovative new therapy to eliminate residual tumor cells and prevent tumor recurrences is critically needed for this deadly disease. A major challenge of GBM research has been the identification of novel molecular therapeutic targets and accurate diagnostic/prognostic biomarkers. Many of the current clinical therapeutic targets of immunotoxins and ligand-directed toxins for high-grade glioma (HGG) cells are surface sialylated glycoproteins. Therefore, methods that systematically and quantitatively analyze cell surface sialoglycoproteins in human clinical tumor samples would be useful for the identification of potential diagnostic markers and therapeutic targets for malignant gliomas. In this study, we used the bioorthogonal chemical reporter strategy (BOCR) in combination with label-free quantitative mass spectrometry (LFQ-MS) to characterize and accurately quantify the individual cell surface sialoproteome in human GBM tissues, in fetal, adult human astrocytes, and in human neural progenitor cells (NPCs). We identified and quantified a total of 843 proteins, including 801 glycoproteins. Among the 843 proteins, 606 (72%) are known cell surface or secreted glycoproteins, including 156 CD-antigens, all major classes of cell surface receptor proteins, transporters, and adhesion proteins. Our findings identified several known as well as new cell surface antigens whose expression is predominantly restricted to human GBM tumors as confirmed by microarray transcription profiling, quantitative RT-PCR and immunohistochemical staining. This report presents the comprehensive identification of new biomarkers and therapeutic targets for the treatment of malignant gliomas using quantitative sialoglycoproteomics with clinically relevant, patient derived primary glioma cells.

Deorphanization of the human leukocyte tyrosine kinase (LTK) receptor by a signaling screen of the extracellular proteome

There are many transmembrane receptor-like proteins whose ligands have not been identified. A strategy for finding ligands when little is known about their tissue source is to screen each extracellular protein individually expressed in an array format by using a sensitive functional readout. Taking this approach, we have screened a large collection (3,191 proteins) of extracellular proteins for their ability to activate signaling of an orphan receptor, leukocyte tyrosine kinase (LTK). Only two related secreted factors, FAM150A and FAM150B (family with sequence similarity 150 member A and member B), stimulated LTK phosphorylation. FAM150A binds LTK extracellular domain with high affinity (K(D) = 28 pM). FAM150A stimulates LTK phosphorylation in a ligand-dependent manner. This strategy provides an efficient approach for identifying functional ligands for other orphan receptors.