The Molecular Detection and Clinical Significance of ALK Rearrangement in Selected Advanced Non-Small Cell Lung Cancer: ALK Expression Provides Insights into ALK Targeted Therapy

Background

This study aimed to elucidate clinical significance of anaplastic lymphoma kinase (ALK) rearrangement in selected advanced non-small cell lung cancer (NSCLC), to compare the application of different ALK detection methods, and especially evaluate a possible association between ALK expression and clinical outcomes in crizotinib-treated patients.

Methods

ALK status was assessed by fluorescent in situ hybridization (FISH), immunohistochemistry (IHC) and quantitative RT-PCR (qRT-PCR) in 173 selected advanced NSCLC patients. Clinicopathologic data, genotype status and survival outcomes were analyzed. Moreover, the association of ALK expression with clinical outcomes was evaluated in ALK FISH-positive crizotinib-treated patients including two patients with concurrent epidermal growth factor receptor (EGFR) mutation.

Results

The positivity detection rate of ALK rearrangement by FISH, IHC and qRT-PCR was 35.5% (59/166), 35.7% (61/171), and 27.9% (34/122), respectively. ALK rearrangement was observed predominantly in young patients, never or light smokers, and adenocarcinomas, especially with signet ring cell features and poor differentiation. Median progression-free survival (PFS) of crizotinib-treated patients was 7.6 months. The overall survival (OS) of these patients was longer compared with that of crizotinib-naive or wild-type cohorts, but there was no significant difference in OS compared with patients with EGFR mutation. ALK expression did not associate with PFS; but, when ALK expression was analyzed as a dichotomous variable, moderate and strong ALK expression had a decreased risk of death (P = 0.026). The two patients with concomitant EGFR and ALK alterations showed difference in ALK expression, response to EGFR and ALK inhibitors, and overall survival.

Conclusions

Selective enrichment according to clinicopathologic features in NSCLC patients could highly improve the positivity detection rate of ALK rearrangement for ALK-targeted therapy. IHC could provide more clues for clinical trial design and therapeutic strategies for ALK-positive NSCLC patients including patients with double genetic aberration of ALK and EGFR.     

An exploration of solvent-front region high affinity moiety leading to novel potent ALK & ROS1 dual inhibitors with mutant-combating effects

The pyrimidine-2,4-diamine analogs exerted excellent activities in down-regulation of ALK phosphorylation. However, the prevalent drug-resistant site-mutation has gradually prevented the agents from being widely used. Herein, we conducted an exploration of high affinity moiety that bound to the solvent-front region (G1202R located) within the ATP binding site of ALK leading to the synthesis of thirty-five pyrimidine-2,4-diamine derivatives. Among these compounds, urea group was extensively derivatized which finally resulted in the identification of the ‘semi-free urea’ compound 39. All compounds were assayed cytotoxicity and enzymatic activities and 39 turned out to be the most potent one with IC₅₀ values of 2.1, 0.91, 4.3 and 0.73 nM towards ALK^wt, ALK^L1196M, ALK^G1202R and ROS1, respectively. The performances of 39 on ALK- & ROS1-dependent cell lines were in good accordance with enzymatic activities with IC₅₀ values below 0.06 µM. Besides, 39 induced cell apoptosis in a dose-dependent manner in H2228 cells. Finally, the binding models of 39 with ALK^wt, ROS1, ALK^L1196M and ALK^G1202R were ideally established which further clearly elucidated their mode of action within the active site.     

Virtual screening and further development of novel ALK inhibitors

Anaplastic lymphoma kinase (ALK) has been in the spotlight in recent years as a promising new target for therapy of non-small-cell lung cancer (NSCLC). Since the identification of the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene in some NSCLC patients was reported in 2007, various research groups have been seeking ALK inhibitors. Above all, crizotinib (PF-02341066) has been under clinical trial, and its therapeutic efficacy of inhibiting ALK in NSCLC has been reported. Among anticancer drugs, drug resistance appears frequently necessitating various kinds of inhibitors. We identified novel ALK inhibitors by virtual screening from the public chemical library collected by the Chemical Biology Research Initiative (CBRI) at the University of Tokyo, and inhibitors that are more potent were developed.     

Discovery of novel tetrahydroisoquinoline-containing pyrimidines as ALK inhibitors

Exploration of the two-position side chain of pyrimidine in LDK378 with tetrahydroisoquinolines (THIQs) led to discovery of 8 and 17 as highly potent ALK inhibitors. THIQs 8 and 17 showed encouraging in vitro and in vivo xenograft efficacies, comparable with those of LDK378. Although THIQ analogs (8a–o and 17a–i) prepared were not as active as their parent compounds, both 8 and 17 have significant inhibitory activities against various ALK mutant enzymes including G1202R, indicating that this series of compounds could be further optimized as useful ALK inhibitors overcoming the resistance issues found from crizotinib and LDK378.     

Insight into drug resistance mechanisms and discovery of potential inhibitors against wild-type and L1196M mutant ALK from FDA-approved drugs

Anaplastic lymphoma kinase (ALK) plays a crucial role in multiple malignant cancers. It is known as a well-established target for the treatment of ALK-dependent cancers. Even though substantial efforts have been made to develop ALK inhibitors, only crizotinib, ceritinib, and alectinib had been approved by the U.S. Food and Drug Administration for patients with ALK-positive non-small cell lung cancer (NSCLC). The secondary mutations with drug-resistance bring up difficulties to develop effective drugs for ALK-positive cancers. To give a comprehensive understanding of molecular mechanism underlying inhibitor response to ALK tyrosine kinase mutations, we established an accurate assessment for the extensive profile of drug against ALK mutations by means of computational approaches. The molecular mechanics-generalized Born surface area (MM-GBSA) method based on molecular dynamics (MD) simulation was carried out to calculate relative binding free energies for receptor-drug systems. In addition, the structure-based virtual screening was utilized to screen effective inhibitors targeting wild-type ALK and the gatekeeper mutation L1196M from 3180 approved drugs. Finally, the mechanism of drug resistance was discussed, several novel potential wild-type and L1196M mutant ALK inhibitors were successfully identified.     

Will the clinical development of 4th-generation “double mutant active” ALK TKIs (TPX-0131 and NVL-655) change the future treatment paradigm of ALK+ NSCLC?

Our current treatment paradigm of advanced anaplastic lymphoma kinase fusion (ALK+) non-small cell lung cancer (NSCLC) classifies the six currently approved ALK tyrosine kinase inhibitors (TKIs) into three generations. The 2nd-generation (2G) and 3rd-generation (3G) ALK TKIs are all “single mutant active” with varying potencies across a wide spectrum of acquired single ALK resistance mutations. There is a vigorous debate among clinicians which is the best upfront ALK TKI is for the first-line (1L) treatment of ALK+ NSCLC and the subsequent sequencing strategies whether it should be based on the presence of specific on-target ALK resistance mutations or not. Regardless, sequential use of “single mutant active” ALK TKIs will eventually lead to double ALK resistance mutations in cis. This has led to the creation of fourth generation (4G) “double mutant active” ALK TKIs such as TPX-0131 and NVL-655. We discuss the critical properties 4G ALK TKIs must possess to be clinically successful. We proposed conceptual first-line, second-line, and molecularly-based third-line registrational randomized clinical trials designed for these 4G ALK TKIs. How these 4G ALK TKIs would be used in the future will depend on which line of treatment the clinical trial design(s) is adopted provided the trial is positive. If approved, 4G ALK TKIs may usher in a new treatment paradigm for advanced ALK+ NSCLC that is based on classifying ALK TKIs based on the intrinsic functional capabilities (“singe mutant active” versus “double mutant active”) rather than the loosely-defined “generational” (first-, second-,third-,fourth-) classification and avoid the current clinical approaches of seemingly random sequential use of 2G and 3G ALK TKIs.     

Pulmonary Sarcomatoid Carcinoma with ALK Rearrangement: Frequency,Clinical-Pathologic Characteristics,and Response to ALK Inhibitor

PURPOSE: The incidence of anaplastic lymphoma kinase (ALK) rearrangement in pulmonary sarcomatoid carcinoma (PSC) is controversial. In this study, we aimed to reveal the reliable frequency and the clinical-pathologic characteristics of pulmonary sarcomatoid carcinoma (PSC) with ALK rearrangement in Chinese population, and to provide insight into the translatability of anti-ALK treatment in this treatment-refractory disease. METHODS: Immunohistochemistry (IHC) using a Ventana anti-ALK (D5F3) rabbit monoclonal antibody was performed in 141 PSC specimens collected from multiple medical centers. IHC-positive cases were then confirmed using ALK fluorescent in situ hybridization (FISH). The incidence rates and clinical-pathologic characteristics of ALK-rearranged PSC were then analyzed. Response to ALK inhibitor crizotinib in a patient with ALK-rearranged PSC was evaluated according to the response evaluation criteria for solid tumors (RECIST) version 1.1. RESULTS: Five of 141 (3.5%) of PSCs showed ALK rearrangement-positive by IHC and then were confirmed by FISH. Two were carcinosarcomas and the other three were pulmonary pleomorphic carcinoma (PPC). Strong positive ALK rearrangement was observed in both the epithelioid and sarcomatoid components. The median age of ALK-positive patients was younger than that of ALK-negative patients. PSCs in never-smokers were more likely to harbor ALK rearrangement than those in former or current smokers (P < .05). A 40-year-old woman diagnosed with ALK-rearranged PPC experienced a partial response (?32%) to the ALK inhibitor crizotinib. CONCLUSIONS: The incidence rates of ALK rearrangement in PSC in the Chinese population are similar to those of other subtypes of NSCLC. PSCs in younger never-smokers are more often to harbor ALK rearrangement. ALK inhibitors may serve as an effective treatment for ALK-rearranged PSC.     

A novel mutation of ALK2, L196P, found in the most benign case of fibrodysplasia ossificans progressiva activates BMP-specific intracellular signaling equivalent to a typical mutation, R206H

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant congenital disorder characterized by progressive heterotopic ossification in muscle tissues. Constitutively activated mutants of a bone morphogenetic protein (BMP) receptor, ALK2, have been identified in patients with FOP. Recently, a novel ALK2 mutation, L196P, was found in the most benign case of FOP reported thus far. In the present study, we examined the biological activities of ALK2(L196P) in vitro. Over-expression of ALK2(L196P) induced BMP-specific activities, including the suppression of myogenesis, the induction of alkaline phosphatase activity, increased BMP-specific luciferase reporter activity, and increased phosphorylation of Smad1/5 but not Erk1/2 or p38. The activities of ALK2(L196P) were higher than those of ALK2(G356D), another mutant ALK2 allele found in patients with FOP and were equivalent to those of ALK2(R206H), a typical mutation found in patients with FOP. ALK2(L196P) was equally or more resistant to inhibitors in comparison to ALK2(R206H). These findings suggest that ALK2(L196P) is an activated BMP receptor equivalent to ALK2(R206H) and that ALK2(L196P) activity may be suppressed in vivo by a novel molecular mechanism in patients with this mutation.     

mTOR inhibitors radiosensitize PTEN‐deficient non‐small‐cell lung cancer cells harboring an EGFR activating mutation by inducing autophagy

Clinical resistance to gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), in patients with lung cancer has been linked to acquisition of the T790M resistance mutation in activated EGFR or amplification of MET. Phosphatase and tensin homolog (PTEN) loss has been recently reported as a gefitinib resistance mechanism in lung cancer. The aim of this study was to evaluate the efficacy of radiotherapy in non‐small‐cell lung cancer (NSCLC) with acquired gefitinib resistance caused by PTEN deficiency to suggest radiotherapy as an alternative to EGFR TKIs. PTEN deficient‐mediated gefitinib resistance was generated in HCC827 cells, an EGFR TKI sensitive NSCLC cell line, by PTEN knockdown with a lentiviral vector expressing short hairpin RNA‐targeting PTEN. The impact of PTEN knockdown on sensitivity to radiation in the presence or absence of PTEN downstream signaling inhibitors was investigated. PTEN knockdown conferred acquired resistance not only to gefitinib but also to radiation on HCC827 cells. mTOR inhibitors alone failed to reduce HCC827 cell viability, regardless of PTEN expression, but ameliorated PTEN knockdown‐induced radioresistance. PTEN knockdown‐mediated radioresistance was accompanied by repression of radiation‐induced cytotoxic autophagy, and treatment with mTOR inhibitors released the repression of cytotoxic autophagy to overcome PTEN knockdown‐induced radioresistance in HCC827 cells. These results suggest that inhibiting mTOR signaling could be an effective strategy to radiosensitize NSCLC harboring the EGFR activating mutation that acquires resistance to both TKIs and radiotherapy due to PTEN loss or inactivation mutations. J. Cell. Biochem. 114: 1248–1256, 2013. © 2012 Wiley Periodicals, Inc.     

RAS-MAPK in ALK targeted therapy resistance

The clinical success of ALK targeted therapy is limited by resistance. To identify rational co-targeting strategies to enhance clinical outcomes, we explored the molecular basis of ALK oncogene dependence in ALK gene rearrangement positive (ALK+) lung adenocarcinoma. We discovered that the RAS-RAF-MEK-ERK pathway is the critical downstream pathway necessary for ALK+ tumor cell survival. Upfront co-targeting of ALK plus MEK enhanced response and forestalled resistance in preclinical ALK+ tumor models, providing rationale for a new approach the treatment of ALK+ patients.     

A molecular dynamics investigation on the crizotinib resistance mechanism of C1156Y mutation in ALK

Crizotinib is an anaplastic lymphoma kinase (ALK) inhibitor that has recently been approved in the US for the treatment of non-small cell lung carcinoma (NSCLC). Despite its outstanding safety and efficacy, several resistant mutations against crizotinib have been detected in the treatment of NSCLC. However, in contrast to the widely accepted mechanism of steric hindrance by mutations at the active site, the mechanism by which the C1156Y non-active site mutation confers resistance against crizotinib remains unclear. In the present study, the resistance mechanism of C1156Y in ALK was investigated using molecular dynamics simulations. The results suggest that despite the non-active site mutation, C1156Y causes the dislocation of crizotinib as well as the indirect conformational changes in the binding cavity, which results in a marked decrease in the van der Waals and electrostatic interactions between crizotinib and ALK. The obtained results provide a detailed explanation of the resistance caused by C1156Y and may give a vital clue for the design of drugs to combat crizotinib resistance.     

Licarin A induces cell death by activation of autophagy and apoptosis in non-small cell lung cancer cells

Lung cancer has a relatively poor prognosis with a low survival rate and drugs that target other cell death mechanism like autophagy may help improving current therapeutic strategy. This study investigated the anti-proliferative effect of Licarin A (LCA) from Myristica fragrans in non-small cell lung cancer cell lines—A549, NCI-H23, NCI-H520 and NCI-H460. LCA inhibited proliferation of all the four cell lines in a dose and time dependent manner with minimum IC50 of 20.03?±?3.12, 22.19?±?1.37 µM in NCI-H23 and A549 cells respectively. Hence NCI-H23 and A549 cells were used to assess the ability LCA to induce autophagy and apoptosis. LCA treatment caused G1 arrest, increase in Beclin 1, LC3II levels and degradation of p62 indicating activation of autophagy in both NCI-H23 and A549 cells. In addition, LCA mediated apoptotic cell death was confirmed by MMP loss, increased ROS, cleaved PARP and decreased pro-caspase3. To understand the role of LCA induced autophagy and its association with apoptosis, cells were analysed following treatment with a late autophagy inhibitor-chloroquine and also after Beclin 1 siRNA transfection. Data indicated that inhibition of autophagy resulted in reduced anti-proliferative as well as pro-apoptotic ability of LCA. These findings confirmed that LCA brought about autophagy dependent apoptosis in non-small cell lung cancer cells and hence it may serve as a potential drug candidate for non-small cell lung cancer therapy.     

KRAS G12V mutation upregulates PD-L1 expression via TGF-β/EMT signaling pathway in human non-small-cell lung cancer

Although clinical data suggest remarkable promise for targeting programmed cell death protein-1 (PD-1) and ligand (PD-L1) signaling in non-small-cell lung cancer (NSCLC), it is still largely undetermined which subtype of patients will be responsive to checkpoint blockade. In the present study, we explored whether PD-L1 was regulated by mutant Kirsten rat sarcoma viral oncogene homolog (KRAS), which is frequently mutated in NSCLC and results in poor prognosis and low survival rates. We verified that PD-L1 levels were dramatically increased in KRAS mutant cell lines, particularly in NCI-H441 cells with KRAS G12V mutation. Overexpression of KRAS G12V remarkably elevated PD-L1 messenger RNA and protein levels, while suppression of KRAS G12V led to decreased PD-L1 levels in NCI-H441 cells. Consistently, higher levels of PD-L1 were observed in KRAS-mutated tissues as well as tumor tissues-derived CD4⁺ and CD8⁺ T cells using a tumor xenograft in B-NDG mice. Mechanically, both in vitro and in vivo assays found that KRAS G12V upregulated PD-L1 via regulating the progression of epithelial-to-mesenchymal transition (EMT). Moreover, pembrolizumab activated the antitumor activity and decreased tumor growth with KRAS G12V mutated NSCLC. This study demonstrates that KRAS G12V mutation could induce PD-L1 expression and promote immune escape via transforming growth factor-β/EMT signaling pathway in KRAS-mutant NSCLC, providing a potential therapeutic approach for NSCLC harboring KRAS mutations.     

Activating ALK mutations found in neuroblastoma are inhibited by Crizotinib and NVP-TAE684

Mutations in the kinase domain of ALK (anaplastic lymphoma kinase) have recently been shown to be important for the progression of the childhood tumour neuroblastoma. In the present study we investigate six of the putative reported constitutively active ALK mutations, in positions G1128A, I1171N, F1174L, R1192P, F1245C and R1275Q. Our analyses were performed in cell-culture-based systems with both mouse and human ALK mutant variants and subsequently in a Drosophila melanogaster model system. Our investigation addressed the transforming potential of the putative gain-of-function ALK mutations as well as their signalling potential and the ability of two ATP-competitive inhibitors, Crizotinib (PF-02341066) and NVP-TAE684, to abrogate the activity of ALK. The results of the present study indicate that all mutations tested are of an activating nature and thus are implicated in tumour initiation or progression of neuroblastoma. Importantly for neuroblastoma patients, all ALK mutations used in the present study can be blocked by the inhibitors, although some mutants exhibited higher levels of drug sensitivity than others.     

ALK Kinase Domain Mutations in Primary Anaplastic Large Cell Lymphoma: Consequences on NPM-ALK Activity and Sensitivity to Tyrosine Kinase Inhibitors

ALK inhibitor crizotinib has shown potent antitumor activity in children with refractory Anaplastic Large Cell Lymphoma (ALCL) and the opportunity to include ALK inhibitors in first-line therapies is oncoming. However, recent studies suggest that crizotinib-resistance mutations may emerge in ALCL patients. In the present study, we analyzed ALK kinase domain mutational status of 36 paediatric ALCL patients at diagnosis to identify point mutations and gene aberrations that could impact on NPM-ALK gene expression, activity and sensitivity to small-molecule inhibitors. Amplicon ultra-deep sequencing of ALK kinase domain detected 2 single point mutations, R335Q and R291Q, in 2 cases, 2 common deletions of exon 23 and 25 in all the patients, and 7 splicing-related INDELs in a variable number of them. The functional impact of missense mutations and INDELs was evaluated. Point mutations were shown to affect protein kinase activity, signalling output and drug sensitivity. INDELs, instead, generated kinase-dead variants with dominant negative effect on NPM-ALK kinase, in virtue of their capacity of forming non-functional heterocomplexes. Consistently, when co-expressed, INDELs increased crizotinib inhibitory activity on NPM-ALK signal processing, as demonstrated by the significant reduction of STAT3 phosphorylation. Functional changes in ALK kinase activity induced by both point mutations and structural rearrangements were resolved by molecular modelling and dynamic simulation analysis, providing novel insights into ALK kinase domain folding and regulation. Therefore, these data suggest that NPM-ALK pre-therapeutic mutations may be found at low frequency in ALCL patients. These mutations occur randomly within the ALK kinase domain and affect protein activity, while preserving responsiveness to crizotinib.     

YM155 sensitizes non-small cell lung cancer cells to EGFR-tyrosine kinase inhibitors through the mechanism of autophagy induction

Resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as erlotinib and gefitinib, is a major clinical problem in the treatment of patients with non-small cell lung cancer (NSCLC). YM155 is a survivin small molecule inhibitor and has been demonstrated to induce cancer cell apoptosis and autophagy. EGFR-TKIs have been known to induce cancer cell autophagy. In this study, we showed that YM155 markedly enhanced the sensitivity of erlotinib to EGFR-TKI resistant NSCLC cell lines H1650 (EGFR exon 19 deletion and PTEN loss) and A549 (EGFR wild type and KRAS mutation) through inducing autophagy-dependent apoptosis and autophagic cell death. The effects of YM155 combined with erlotinib on apoptosis and autophagy inductions were more obvious than those of YM155 in combination with survivin knockdown by siRNA transfection, suggesting that YM155 induced autophagy and apoptosis in the NSCLC cells partially depend on survivin downregulation. Meanwhile, we found that the AKT/mTOR pathway is involved in modulation of survivin downregulation and autophagy induction caused by YM155. In addition, YM155 can induce DNA damage in H1650 and A549 cell lines. Moreover, combining erlotinib further augmented DNA damage by YM155, which were retarded by autophagy inhibitor 3MA, or knockdown of autophagy-related protein Beclin 1, revealing that YM155 induced DNA damage is autophagy-dependent. Similar results were also observed in vivo xenograft experiments. Therefore, combination of YM155 and erlotinib offers a promising therapeutic strategy in NSCLC with EGFR-TKI resistant phenotype.     

Autophagy Protects from Trastuzumab-Induced Cytotoxicity in HER2 Overexpressing Breast Tumor Spheroids

Multicellular tumor spheroids represent a 3D in vitro model that mimics solid tumor essential properties including assembly and development of extracellular matrix and nutrient, oxygen and proliferation gradients. In the present study, we analyze the impact of 3D spatial organization of HER2-overexpressing breast cancer cells on the response to Trastuzumab. We cultured human mammary adenocarcinoma cell lines as spheroids with the hanging drop method and we observed a gradient of proliferating, quiescent, hypoxic, apoptotic and autophagic cells towards the inner core. This 3D organization decreased Trastuzumab sensitivity of HER2 over-expressing cells compared to monolayer cell cultures. We did not observe apoptosis induced by Trastuzumab but found cell arrest in G0/G1 phase. Moreover, the treatment downregulated the basal apoptosis only found in tumor spheroids, by eliciting protective autophagy. We were able to increase sensitivity to Trastuzumab by autophagy inhibition, thus exposing the interaction between apoptosis and autophagy. We confirmed this result by developing a resistant cell line that was more sensitive to autophagy inhibition than the parental BT474 cells. In summary, the development of Trastuzumab resistance relies on the balance between death and survival mechanisms, characteristic of 3D cell organization. We propose the use of spheroids to further improve the understanding of Trastuzumab antitumor activity and overcome resistance.     

Molecular inhibitory mechanism study on the potent inhibitor brigatinib against four crizotinib-resistant ALK mutations

As a potent and selective drug, brigatinib exhibits high efficacy against wild-type and mutant anaplastic lymphoma kinase (ALK) proteins to treat non–small cell lung cancer. In this work, the mechanisms of brigatinib binding to wild type and four mutant ALKs were investigated to gain insight into the dynamic energetic and structural information with respect to the design of novel inhibitors. Comparison between ALK-brigatinib and ALK-crizotinib suggests that the scaffold of brigatinib is well anchored to the residue Met1199 of hinge region by two hydrogen bonds, and the residue Lys1150 has the strong electrostatic interaction with the dimethylphosphine oxide moiety in brigatinib. These ALK mutations have significant influences on the flexibility of P-loop region and DFG sequences, but do not impair the hydrogen bonds between brigatinib and the residue Met1199 of hinge region. And mutations (L1196M, G1269A, F1174L, and R1275Q) induce diverse conformational changes of brigatinib and the obvious energy variation of residues Glu1167, Arg1209, Asp1270, and Asp1203. Together, the detailed explanation of mechanisms of those mutations with brigatinib further provide several guidelines for the development of more effective ALK inhibitors.     

Stimulation of ALK by the growth factor midkine renders glioma cells resistant to autophagy-mediated cell death

Δ?-tetrahydrocannabinol (THC), the main active component of marijuana, promotes cancer cell death via autophagy stimulation. We find that activation of the tyrosine kinase receptor ALK by its ligand midkine interferes with the signaling mechanism by which THC promotes autophagy-mediated glioma cell death.     

Detection of anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer and related issues in ALK inhibitor therapy: a literature review

Anaplastic lymphoma kinase (ALK) encodes a receptor tyrosine kinase, and ALK gene rearrangement (ALK+) is implicated in the oncogenesis of non-small cell lung carcinomas (NSCLCs), especially adenocarcinomas. The ALK inhibitor crizotinib was approved in August 2011 by the US Food and Drug Administration (FDA) for treating late-stage NSCLCs that are ALK+, with a companion fluorescent in situ hybridization (FISH) test using the Vysis ALK Break Apart FISH Probe Kit. This review covers pertinent issues in ALK testing, including approaches to select target patients for the test, pros and cons of different detection methods, and mechanisms as well as monitoring of acquired crizotinib resistance in ALK+ NSCLCs.