Nucleophosmin-anaplastic Lymphoma Kinase Research Articles

Abstract 7015: Crosstalk between histone and DNA methylation in the development and progression of ALK+ ALCL

Abstract ALK-positive anaplastic large cell lymphoma (ALK+ ALCL) is a T-cell non-Hodgkin lymphoma characterized by the presence of the fusion oncogene nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). Tumor cells control the expression of key genes in different manners: mutations, translocations or epigenetically. Our group have shown that in this tumor a plethora of genes are silenced by NPM-ALK through DNA methylation. However, recent evidence showed that some of the genes downregulated by DNA methylation might have already been silenced prior to the appearance of DNA methylation. Herein, we investigate the possible role of histone methylation in the silencing of genes and its relationship to DNA methylation. To better understand the possible players in the silencing of genes in ALK+ ALCL we used T-cell transformed with NPM-ALK and recorded over time the changing in gene expression, DNA methylation and histone marks. Using RNAseq comparing transformed cells at different time points, we noticed that downregulated genes in ALK+ ALCL became gradually silenced also in our system. Next, we investigated the DNA methylation (meDNA) on their promoters, and we confirmed a progressive increase of meDNA but clearly slower compared to the silencing of the genes, or if compared to the meDNA status of established ALK+ ALCL cell lines. Finally, we explored the presence of silencing histone marks on the promoter of the silenced genes using qPCR-ChIP. Among the repressive histone marks evaluated, H3K27me3 stood up as possible candidate for the gene silencing. Therefore, we look at the different gene expression changes after the inhibition of either meDNA, using a DNMT1 inhibitor (GSK3685032), or histone methylation, by EZH2 inhibitor (EPZ6438). RNAseq data showed the re-expression of downregulated genes after EZH2 and/or DNMT1 inhibition providing clear insights on their epigenetic regulation. The co-presence of H3K27me3 and meDNA on the promoters of those genes points towards a crosstalk between DNA and histone methylation machineries. Despite it is clear how NPM-ALK regulates DNA methylation, nothing is known about NPM-ALK and EZH2. To investigate their relationship, we treated ALK+ cells with ALK inhibitor, and we observed a decrease of EZH2 expression at protein and mRNA level. STAT3 inhibition, through napabucasin or by STAT3 silencing using Crispr-cas9 technology, resulted, likewise, in the downregulation of EZH2. Moreover, ChIPseq showed STAT3 presence on EZH2 promoter, further confirming this mechanism. Altogether, those data showed that NPM-ALK regulates EZH2 expression through STAT3. In conclusion, we provide, not only novel information on the mechanism in the downregulation of genes in ALK+ ALCL, but also new insight on the understanding of the epigenetics machinery and the crosstalk between histone and DNA methylation, for long time considered two mutually exclusive mechanisms, or even antagonist. Citation Format: Cosimo Lobello, Shengchun Wang, Shilpa Rao, Jan Pawlicki, Nashwa Mansoor, James L. Riley, Reza Nejati, Wasik A. Mariusz. Crosstalk between histone and DNA methylation in the development and progression of ALK+ ALCL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7015.

Distinct Subtypes of Chemotherapy-Resistant Systemic ALK-Positive Anaplastic Large Cell Lymphoma Demonstrate Long-Term Complete Remissions to Imatinib

Background Platelet-derived growth factor receptor (PDGFR) is expressed in nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) positive anaplastic large cell lymphomas (ALCL ALK+). Our previous preclinical research suggested that PDGFR blockade by the Abl/c-Kit/PDGFR kinase inhibitor imatinib could be an effective treatment strategy for ALCL ALK+. An indicator patient whose ALCL cells expressed PDGFR and who failed three treatment lines (including autologous stem cell transplantation) achieved complete remission (CR) with imatinib. Methods We treated 6 relapsed/refractory (r/r) ALK+ ALCL patients with imatinib, 4 of which within the prospective clinical trial, EudraCT No.: 2013-003505-26. Median follow-up was 40 months (160 weeks, range 4 - 428). Patients were characterized by whole exome sequencing, bisulfite sequencing, RNA-sequencing and immunological profiling. Whole exome sequencing data were integrated and compared to 32 additional ALK+ ALCL patients (Larose et. al., Haematologica, 2021; Creszenzo et al., Cancer Cell 2015; Mologni et al. (unpublished). Results 5-year progression-free survival (PFS) was 67%. 4 out of 6 patients achieved a CR that was maintained throughout the follow-up of 3.3 - 8.9 years. Lymphoma cells of the non-responding patients did not express PDGFRA/B as confirmed by immunohistochemistry and RNA-scope (panel figure A). Cytoplasmic co-expression of both, ALK and PDGFRA/B, in ALCL tumor cells was associated with complete response to imatinib in ALK+ ALCL patients. Methylation profiling confirmed a differentially activated PDGFR axis between responders and non-responders and identified a specific protein kinase profile that included a significant inflammatory upregulation of HGFAC, VEGFa, and TNFa in serum cytokine profiling. The transcriptional differential gene expression includes an upregulation of genes of GO:0045859 (regulation of protein kinase activity) in non-resonders. Ident pathologic variants resulting in amino-acid changes were detected in non-responders in mutated genes linked to kinase activity ( TBC1D28 E56A), protein processing ( EMC1 S323T: cosmicV64345386 and EMC1S325N: cosmicV100916421; and GOLGA8S) and cytokine signaling ( IFNL2, ZFYVE19). The imatinib-resitance profile involving mutations in EMC1 and GOLGA8S could be detected at a frequency of 6/32 (19%) in an independent reference cohort of r/r ALK+ALCL (panel figure B). Exclusive mutations in PPP1R13B linked to p53-pathway were found in all responders. PDGFRA mutations with low allele frequencies (2-5%) were identified soley in imatinib-responders. Additionally, non-responders were characterized by an exclusive mutational signature linked to vesicular endocytosis and cytokine signaling as a resistance mechanism to pan-kinase inhibitor imatinib. Conclusion PDGFRA/B expression in tumour cells of therapy-resistant ALK-positive ALCL patients can discriminate genetically and functionally distinct lymphoma subgroups that are directly related to long-term treatment response to kinase inhibitor imatinib. Our data suggests that significant imatinib responses may be achieved in more than 80% of chemotherapy-resistant ALK+ ALCL cases.

The acetylation of STAT3 at K685 attenuates NPM-ALK-induced tumorigenesis

Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), a fusion protein generated by a chromosomal translocation, is a causative gene product of anaplastic large cell lymphoma (ALCL). It induces cell proliferation and tumorigenesis by activating the transcription factor, signal transducer and activator of transcription factor 3 (STAT3). We herein demonstrated that STAT3 underwent acetylation at K685 in a manner that was dependent on the kinase activity of NPM-ALK. To investigate the role of STAT3 acetylation in NPM-ALK-induced oncogenesis, we generated Ba/F3 cells expressing NPM-ALK in which STAT3 was silenced by shRNA, named STAT3-KD cells, and then reconstituted wild-type STAT3 or the STAT3 K685R mutant into these cells. The phosphorylation level of the K685R mutant at Y705 and S727 was significantly higher than that of wild-type STAT3 in STAT3-KD cells. The expression of STAT3 target genes, such as IL-6, Pim1, Pim2, and Socs3, was more strongly induced by the reconstitution of the K685R mutant than wild-type STAT3. In addition, the proliferative ability of STAT3-KD cells reconstituted with the K685R mutant was slightly higher than that of STAT3-KD cells reconstituted with wild-type STAT3. In comparisons with the inoculation of STAT3-KD cells reconstituted with wild-type STAT3, the inoculation of STAT3-KD cells reconstituted with the K685R mutant significantly enhanced tumorigenesis and hepatosplenomegaly in nude mice. Collectively, these results revealed for the first time that the acetylation of STAT3 at K685 attenuated NPM-ALK-induced oncogenesis.

BRG1 and NPM-ALK Are Co-Regulated in Anaplastic Large-Cell Lymphoma; BRG1 Is a Potential Therapeutic Target in ALCL.

Simple SummaryT-cell lymphoma is a cancer of the immune system. One specific sub-type of T-cell lymphoma is a malignancy called anaplastic large cell lymphoma (ALCL), which is distinct from the other forms, as in general, it has a better prognosis. Research conducted to understand why ALCL develops has shown that a specific genetic event occurs, whereby a new protein is created that drives tumour growth. This protein is called nucleophosmin–anaplastic lymphoma kinase (NPM-ALK). Our research, described here, shows that NPM-ALK regulates another protein, called BRG1, to drive proliferation of tumour cells. In turn, when the gene that leads to expression of BRG1 is inactivated, the tumour cells die. These data suggest that therapeutic targeting of BRG1 might be a novel therapy for this form of cancer.Anaplastic large-cell lymphoma (ALCL) is a T-cell malignancy driven in many cases by the product of a chromosomal translocation, nucleophosmin–anaplastic lymphoma kinase (NPM-ALK). NPM-ALK activates a plethora of pathways that drive the hallmarks of cancer, largely signalling pathways normally associated with cytokine and/or T-cell receptor-induced signalling. However, NPM-ALK is also located in the nucleus and its functions in this cellular compartment for the most part remain to be determined. We show that ALCL cell lines and primary patient tumours express the transcriptional activator BRG1 in a NPM-ALK-dependent manner. NPM-ALK regulates expression of BRG1 by post-translational mechanisms dependent on its kinase activity, protecting it from proteasomal degradation. Furthermore, we show that BRG1 drives a transcriptional programme associated with cell cycle progression. In turn, inhibition of BRG1 expression with specific shRNA decreases cell viability, suggesting that it may represent a key therapeutic target for the treatment of ALCL.

Nucleophosmin-anaplastic lymphoma kinase of anaplastic large-cell lymphoma recruits, activates, and uses pp60c-src to mediate its mitogenicity

Anaplastic large-cell lymphomas (ALCLs) are lymphomas of T or null phenotype often associated with a chromosomal translocation, t(2;5)(p23;q35). This translocation leads to the expression of a hybrid protein consisting of the N-terminal portion of nucleophosmin (NPM) and the intracellular domain of the anaplastic lymphoma kinase (ALK). NPM-ALK possesses a constitutive tyrosine kinase activity responsible for its oncogenic property through activation of downstream effectors such as phospholipase C gamma (PLC-gamma) and the type IA phosphoinositide 3-kinase. Here, we show that the Src-kinases, particularly pp60(c-src), associate with and are activated by NPM-ALK expression in various cells, and in cell lines established from patients with ALCL. The kinase activity and the tyrosine 418 of NPM-ALK are required for its association with Src-kinases. Y418F mutation of NPM-ALK impaired its association with Src-kinases and strongly reduced the proliferation rate of Ba/F3 cells. In agreement, Src-kinase inhibitors or pp60(c-src) siRNA significantly decreased the proliferation rate of NPM-ALK-positive ALCL cell lines. Moreover, using active or inactive forms of pp60(c-src) and NPM-ALK, we provide evidence that NPM-ALK is a potential substrate of pp60(c-src). Overall, our data place Src-kinases as new important downstream effectors of NPM-ALK and as attractive potential therapeutic targets for new ALCL treatment.

Requirement of DNMT1 to orchestrate epigenomic reprogramming for NPM-ALK-driven lymphomagenesis.

Malignant transformation depends on genetic and epigenetic events that result in a burst of deregulated gene expression and chromatin changes. To dissect the sequence of events in this process, we used a T-cell-specific lymphoma model based on the human oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) translocation. We find that transformation of T cells shifts thymic cell populations to an undifferentiated immunophenotype, which occurs only after a period of latency, accompanied by induction of the MYC-NOTCH1 axis and deregulation of key epigenetic enzymes. We discover aberrant DNA methylation patterns, overlapping with regulatory regions, plus a high degree of epigenetic heterogeneity between individual tumors. In addition, ALK-positive tumors show a loss of associated methylation patterns of neighboring CpG sites. Notably, deletion of the maintenance DNA methyltransferase DNMT1 completely abrogates lymphomagenesis in this model, despite oncogenic signaling through NPM-ALK, suggesting that faithful maintenance of tumor-specific methylation through DNMT1 is essential for sustained proliferation and tumorigenesis.

EBP2, a novel NPM-ALK-interacting protein in the nucleolus, contributes to the proliferation of ALCL cells by regulating tumor suppressor p53.

The oncogenic fusion protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), found in anaplastic large-cell lymphoma (ALCL), localizes to the cytosol, nucleoplasm, and nucleolus. However, the relationship between its localization and transforming activity remains unclear. We herein demonstrated that NPM-ALK localized to the nucleolus by binding to nucleophosmin 1 (NPM1), a nucleolar protein that exhibits shuttling activity between the nucleolus and cytoplasm, in a manner that was dependent on its kinase activity. In the nucleolus, NPM-ALK interacted with Epstein-Barr virus nuclear antigen 1-binding protein 2 (EBP2), which is involved in rRNA biosynthesis. Moreover, enforced expression of NPM-ALK induced tyrosine phosphorylation of EBP2. Knockdown of EBP2 promoted the activation of the tumor suppressor p53, leading to G0 /G1 -phase cell cycle arrest in Ba/F3 cells transformed by NPM-ALK and ALCL patient-derived Ki-JK cells, but not ALCL patient-derived SUDH-L1 cells harboring p53 gene mutation. In Ba/F3 cells transformed by NPM-ALK and Ki-JK cells, p53 activation induced by knockdown of EBP2 was significantly inhibited by Akt inhibitor GDC-0068, mTORC1 inhibitor rapamycin, and knockdown of Raptor, an essential component of mTORC1. These results suggest that the knockdown of EBP2 triggered p53 activation through the Akt-mTORC1 pathway in NPM-ALK-positive cells. Collectively, the present results revealed the critical repressive mechanism of p53 activity by EBP2 and provide a novel therapeutic strategy for the treatment of ALCL.

N-Acetyl cysteine prevents activities of STAT3 inhibitors, Stattic and BP-1-102 independently of its antioxidant properties.

Inhibitors for signal transducer and activator of transcription 3 (STAT3), Stattic, BP-1-102, and LLL12 significantly induce apoptosis in transformed Ba/F3 cells expressing an oncogenic fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) that induces the activation of STAT3. We found that the antioxidant reagent, N-acetyl cysteine (NAC) prevented the abilities of Stattic and BP-1-102, but not LLL12 to induce apoptosis in transformed cells expressing NPM-ALK, providing a novel problem in use of STAT3 inhibitors. We herein investigated the mechanisms how NAC prevented the effects of Sttatic and BP-1-102. Ba/F3 cells expressing NPM-ALK and SUDHL-1 cells were treated with antioxidants such as NAC, Trolox or edaravone in combination with STAT3 inhibitors. Phosphorylation of STAT3, cell proliferation rate, cell viability, cell cycle, internucleosomal DNA fragmentation and the intracellular accumulation of reactive oxygen species (ROS) was investigated. The binding of STAT3 inhibitors and NAC was analyzed by LC-MS. NAC but not Trolox and edaravone diminished the abilities of Stattic and BP-1-102 to induce apoptosis in cells expressing NPM-ALK. The ROS levels in cells expressing NPM-ALK were not markedly affected by the treatments with Stattic and BP-1-102 in combination with NAC, suggesting that NAC inhibited the activity of Stattic and BP-1-102 independent of its antioxidant activity. LC-MS analysis revealed that NAC directly bound to Stattic and BP-1-102. Furthermore, these NAC adducts exhibited no cytotoxicity, and failed to affect the activity of STAT3. NAC antagonizes the activities of Stattic and BP-1-102, which inhibit STAT3 activation by interacting with cysteine residues in STAT3.

Methotrexate significantly induces apoptosis by inhibiting STAT3 activation in NPM-ALK-positive ALCL cells

Anaplastic large cell lymphoma (ALCL) is associated with a characteristic chromosomal translocation that generates the oncogenic fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). Methotrexate is a commonly used chemotherapeutic drug in the treatment of multiple cancers due to its inhibition of dihydrofolate reductase (DHFR), which suppresses the synthesis of DNA. In the present study, we found that low-dose methotrexate significantly induced apoptosis in transformed Ba/F3 cells expressing NPM-ALK by inhibiting the activation of signal transducer and activator of transcription factor 3 (STAT3), a critical downstream molecule of NPM-ALK. Although methotrexate prevented the phosphorylation of STAT3, it did not affect the activity of NPM-ALK. A co-treatment with folinic acid prevented the methotrexate-induced inhibition of STAT3 activation and induction of apoptosis, suggesting that methotrexate exerts its cytotoxic effects by depleting tetrahydrofolate (THF) in transformed cells by NPM-ALK. Furthermore, methotrexate induced the down-regulation of the anti-apoptotic protein, MCL-1, DNA damage, and the activation of a p53 tumor suppressor, leading to apoptosis through the inhibition of STAT3. Methotrexate significantly induced apoptosis in ALK inhibitor-resistant cells expressing the NPM-ALK mutant harboring the point mutation, G262R, and in ALCL patient-derived NPM-ALK-positive Ki-JK cells. Collectively, these results demonstrate the potential therapeutic application of methotrexate, which inhibits the activation of STAT3, to NPM-ALK-positive ALCL.

NPM-ALK-reactive T-cell responses in children and adolescents with NPM-ALK positive anaplastic large cell lymphoma

ABSTRACTThe oncoantigen nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) induces cellular and humoral immune responses in patients with NPM-ALK-positive anaplastic large cell lymphoma (ALCL). We characterize the NPM-ALK-specific T-cell responses in a cohort of pediatric and adolescent ALCL-patients in remission without Human Leucocyte Antigen (HLA)-preselection.First, we assessed NPM-ALK-reactive T-cell responses and their HLA-class I restriction in patients by using dendritic cells (DCs) transfected with in vitro transcribed (IVT) NPM-ALK-RNA for CD8 (n = 20) or CD3 (n = 9) T-cell stimulation. NPM-ALK-specific T-cells were detected in twelve of 29 patients (nine of 20 with CD8-selected and three of nine with CD3-selected cells). Recognition of NPM-ALK was restricted by HLA-C alleles in six of eight, and by HLA-B alleles in four of eight analyzed patients. No NPM-ALK-reactivity was detected in 20 healthy individuals.Second, in order to define possible immunogenic NPM-ALK-epitope regions, DCs pulsed with pools of overlapping long NPM-ALK-peptides were used to stimulate T-cells in further 22 patients and ten controls. Responsive T-cells were detected in 15 patients and in five controls. A peptide pool located in the middle of the kinase domain induced ALK-reactive T-cells in 14 of 15 responsive patients. We could narrow to single peptides between p327-p370 of NPM-ALK in four patients.In conclusion, using IVT-RNA, 40% of NPM-ALK-positive ALCL-patients in remission had detectable NPM-ALK-specific T-cell responses which were mainly restricted by HLA-B and -C alleles. Peptide stimulation of T-cells revealed responses in almost 70% of patients and allowed describing an immunogenic region located in the ALK-kinase domain.

The Transcriptional Regulator Sin3A Contributes to the Oncogenic Potential of STAT3.

Epigenetic silencing of promoter and enhancer regions is a common phenomenon in malignant cells. The transcription factor STAT3 is aberrantly activated in several tumors, where its constitutive acetylation accounts for the transcriptional repression of a number of tumor suppressor genes (TSG) via molecular mechanisms that remain to be understood. Using nucleophosmin-anaplastic lymphoma kinase-positive (NPM-ALK+) anaplastic large-cell lymphoma (ALCL) as model system, we found in cells and patient-derived tumor xenografts that STAT3 is constitutively acetylated as a result of ALK activity. STAT3 acetylation relied on intact ALK-induced PI3K- and mTORC1-dependent signaling and was sensitive to resveratrol. Resveratrol lowered STAT3 acetylation, rescued TSG expression, and induced ALCL apoptotic cell death. STAT3 constitutively bound the Sin3A transcriptional repressor complex, and both STAT3 and Sin3A bound the promoter region of silenced TSG via a resveratrol-sensitive mechanism. Silencing SIN3A caused reexpression of TSG, induced ALCL apoptotic cell death in vitro, and hindered ALCL tumorigenic potential in vivo. A constitutive STAT3-Sin3A interaction was also found in breast adenocarcinoma cells and proved critical for TSG silencing and cell survival. Collectively, these results suggest that oncogene-driven STAT3 acetylation and its constitutive association with Sin3A represent novel and concomitant events contributing to STAT3 oncogenic potential. SIGNIFICANCE: This study delineates the transcriptional regulatory complex Sin3A as a mediator of STAT3 transcriptional repressor activity and identifies the STAT3/Sin3A axis as a druggable target to antagonize STAT3-addicted tumors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/12/3076/F1.large.jpg.See related commentary by Monteleone and Poli, p. 3031.

Crizotinib enhances anti-CD30-LDM induced antitumor efficacy in NPM-ALK positive anaplastic large cell lymphoma

Combining antibody-drug conjugates (ADCs) with targeted small-molecule inhibitors can enhance antitumor effects beyond those attainable with monotherapy. In this study, we investigated the therapeutic combination of a CD30-targeting ADC (anti-CD30-lidamycin [LDM]) with a small-molecule inhibitor (crizotinib) of nucleophosmin-anaplastic lymphoma kinase NPM-ALK in CD30+/ALK+ anaplastic large cell lymphoma (ALCL). In vitro, anti-CD30-LDM showed strong synergistic antiproliferative activity when combined with crizotinib. Furthermore, treatment with anti-CD30-LDM plus crizotinib resulted in a stronger induction of cell apoptosis than monotherapy with either treatment. Western blot analysis revealed that ERK1/2 phosphorylation was increased in response to anti-CD30-LDM-induced DNA damage. Interestingly, the addition of crizotinib inhibited the expression of phosphorylated ERK1/2 and further augmented anti-CD30-LDM-mediated apoptosis, providing a potential synergistic mechanism for DNA-damaging agents combined with NPM-ALK inhibitors. In Karpas299 and SU-DHL-1 xenograft models, anti-CD30-LDM plus crizotinib was more effective in inhibiting tumor growth than either treatment alone. This research demonstrated for the first time that the combination of anti-CD30-LDM and crizotinib exhibits a synergistic inhibitory effect in tumor cells. These results provide scientific support for future clinical evaluations of anti-CD30-LDM, or other DNA-damaging agents, combined with NPM-ALK inhibitors.

Modulating SIRT1 activity variously affects thymic lymphoma development in mice

SIRT1 is a protein deacetylase with a broad range of biological functions, many of which are known to be important in carcinogenesis, however much of the literature regarding the role of SIRT1 in cancer remains conflicting. In this study we assessed the effect of SIRT1 on the initiation and progression of thymic T cell lymphomas. We employed mouse strains in which SIRT1 activity was absent or could be reversibly modulated in conjunction with thymic lymphoma induction using either the N-nitroso-N-methylurea (NMU) carcinogenesis or the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) transgene. Decreased SIRT1 activity reduced the development of thymic lymphomas in the NMU-treated mice but was permissive for the formation of lung adenomas. Conversely, in the NPM-ALK transgenic mice, decreased SIRT1 activity had a modest promoting effect in the development of thymic lymphomas. The results of the work presented here add to the growing body of evidence that sirt1 is neither an outright oncogene nor a tumor suppressor. These opposing results in two models of the same disease suggest that the influence of sirt1 on carcinogenesis may lie in a role in tumor surveillance.

Characterization and diagnostic application of genomic NPM-ALK fusion sequences in anaplastic large-cell lymphoma.

Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) fusion genes resulting from the translocation t(2;5)(p23;q35) are present in almost 90% of childhood ALK-positive anaplastic large-cell lymphomas (ALCL). Detection and quantification of minimal disseminated disease (MDD) by measuring NPM-ALK fusion transcript levels in the blood provide independent prognostic parameters. Characterization of the genomic breakpoints provides insights into the pathogenesis of the translocation and allows for DNA-based minimal disease monitoring.We designed a nested multiplex PCR assay for identification and characterization of genomic NPM-ALK fusion sequences in 45 pediatric ALCL-patients, and used the sequences for quantitative MDD monitoring. Breakpoint analysis indicates the involvement of inaccurate non-homologous end joining repair mechanisms in the formation of NPM-ALK fusions. Parallel quantification of RNA and DNA levels in the cellular fraction of 45 blood samples from eight patients with NPM-ALK-positive ALCL correlated, as did cell-free circulating NPM-ALK DNA copies in the plasma fraction of 37 blood samples. With genomic NPM-ALK fusion sequence quantification, plasma samples of ALCL patients become an additional source for MRD-assessment. Parallel quantification of NPM-ALK transcripts and fusion genes in ALCL cell lines treated with the ALK kinase inhibitor crizotinib illustrates the potential value of supplementary DNA-based quantification in particular clinical settings.

5-chloro-N4-(2-(isopropylsulfonyl)phenyl)-N2-(2-methoxy-4-(4-((4-methylpiperazin-1-yl)methyl)-1H-1,2,3-triazol-1-yl)phenyl)pyrimidine-2,4-diamine (WY-135), a novel ALK inhibitor, induces cell cycle arrest and apoptosis through inhibiting ALK and its downstream pathways in Karpas299 and H2228 cells

Anaplastic lymphoma kinase (ALK)-positive cancers have rising morbidity and mortality in recent years, and novel chemotherapeutic drugs with no drug resistance and high activity for treating ALK-positive cancers are needed urgently. In this study, we investigated the anti-cancer effect of 5-chloro-N4-(2-(isopropylsulfonyl)phenyl)-N2-(2-methoxy-4-(4-((4-methylpiperazin-1-yl)methyl)-1H-1,2,3-triazol-1-yl)phenyl)pyrimidine-2,4-diamine (WY-135), a novel ALK inhibitor, on nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) positive cancer cell line Karpas299 and echinoderm microtubule associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) positive cancer cell line H2228. In vitro enzyme assay showed that WY-135 had better enzyme inhibitory activity than ceritinib. MTT assay showed that WY-135 had similar inhibitory activity with ceritinib in Karpas299 and H2228 cells. The cell cycle analysis proved that WY-135 induced cell cycle arrest at G1 phase in a dose-dependent manner and subsequently progressed into apoptosis. Real-time PCR analysis revealed that the mRNA level of ALK was significantly reduced in Karpas299 and H2228 cells treatment with WY-135. Furthermore, western blot analysis showed that WY-135 significantly suppressed ALK and its downstream protein expression. Taken together, WY-135 exhibits significant anti-cancer activity through inhibiting ALK and its downstream protein expression, arresting cell cycle and eventually inducing cell apoptosis in Karpas299 and H2228 cells. WY-135 is a promising ALK inhibitor with novel structure that has tremendous potentials for therapeutic treatment of NPM-ALK or EML4-ALK positive cancers.

Alpha-tocopherol attenuates the anti-tumor activity of crizotinib against cells transformed by NPM-ALK.

Anaplastic large cell lymphomas (ALCL) are mainly characterized by harboring the fusion protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). The ALK inhibitor, crizotinib specifically induced apoptosis in Ba/F3 cells expressing NPM-ALK by inhibiting the activation of NPM-ALK and its downstream molecule, signal transducer and activator of transcription factor 3 (STAT3). We found that α-tocopherol, a major component of vitamin E, attenuated the effects of crizotinib independently of its anti-oxidant properties. Although α-tocopherol suppressed the inhibitory effects of crizotinib on the signaling axis including NPM-ALK and STAT3, it had no influence on the intake of crizotinib into cells. Crizotinib also directly inhibited the kinase activity of NPM-ALK; however, this inhibitory effect was not altered by the co-treatment with α-tocopherol. Whereas the nuclear localization of NPM-ALK was disappeared by the treatment with crizotinib, the co-treatment with α-tocopherol swept the effect of crizotinib and caused the localization of NPM-ALK in nucleus. The administration of α-tocopherol attenuated the anti-tumor activity of crizotinib against NPM-ALK-provoked tumorigenesis in vivo. Furthermore, the α-tocopherol-induced inhibition of crizotinib-caused apoptosis was also observed in NPM-ALK-positive cells derived from ALCL patients, namely, SUDHL-1 and Ki-JK. Collectively, these results not only revealed the novel mechanism underlying crizotinib-induced apoptosis in NPM-ALK-positive cells, but also suggest that the anti-tumor effects of crizotinib are attenuated when it is taken in combination with vitamin E.

Crizotinib in Combination with Everolimus Synergistically Inhibits Proliferation of Anaplastic Lymphoma Kinase‒Positive Anaplastic Large Cell Lymphoma.

PurposeAnaplastic large cell lymphoma (ALCL) is a rare aggresive non-Hodgkin lymphoma, of which over 50% of cases have an aberrant nucleophosmin (NPM)‒anaplastic lymphoma kinase (ALK) fusion protein. Both mechanistic target of rapamycin (mTOR) inhibitor everolimus and ALK inhibitor crizotinib have shown promising antitumor activity in ALK-positive cancer cell lines. However, their combined effect has not yet been investigated.Materials and MethodsWe evaluated the anti-proliferative effects of everolimus and/or crizotinib in ALK-positive ALCL cell lines, Karpas 299 and SU-DHL-1, and lung adenocarcinoma cell line, NCI-H2228.ResultsWe found that individually, both everolimus and crizotinib potently inhibited cell growth in a dose-dependent manner in both Karpas 299 and SU-DHL-1 cells. A combination of these agents synergistically inhibited proliferation in the two cell lines. Crizotinib down-regulated aberrant AKT and ERK phosphorylation induced by everolimus. Combination treatment also significantly increased G0/G1 cell-cycle arrest, DNA damage, and apoptosis compared with everolimus or crizotinib alone in ALK-positive ALCL cells. In the Karpas 299 xenograft model, the combination treatment exerted a stronger antitumor effect than monotherapies, without significant change in body weight. The synergistic effect of everolimus and crizotinib was also reproduced in the ALK-positive lung adenocarcinoma cell line NCI-H2228. The combination treatment abrogated phosphoinositide 3-kinase/AKT and mTOR signaling pathways with little effect on the Ras/ERK pathway in NCI-H2228 cells.ConclusionCrizotinib combinedwith everolimus synergistically inhibits proliferation of ALK-positive ALCL cells. Our results suggest that this novel combination is worthy of further clinical development in patients with ALK-positive ALCL.

CD30 Induces Heat Shock Protein 90 and Signal Integration in Classic Hodgkin Lymphoma Cells

Previous studies report deregulation of multiple signaling pathways in classic Hodgkin lymphoma (cHL) cells. However, the mechanisms of how these pathways are integrated are not fully understood. Herein, we show involvement of cHL hallmark antigen CD30 in this process. CD30 facilitates phosphorylation of heat shock factor 1, activates heat shock promoter element, and induces heat shock protein (HSP) 90. CD30 repression and subsequent inhibition of HSP90 suppresses NF-κB, extracellular signal-regulated kinase, AKT, and STAT pathways in cHL cell lines. Thus, CD30-mediated induction of HSP90 appears to serve as a central hub for integration of intracellular signaling in cHL cells. We also show that CD30 induces HSP90 through phosphorylation of heat shock factor 1 via c-Jun N-terminal kinase in cHL cells. Although anaplastic large-cell lymphoma (ALCL) also is associated with CD30 overexpression, our experiments reveal that HSP90 induction in ALCL-bearing nucleophosmin-anaplastic lymphoma kinase (ALK) does not depend on CD30 but instead on ALK via c-Jun N-terminal kinase. Together, these results highlight a novel role for CD30 in mediating integration of signaling pathways of cHL cells while being replaced in this function by ALK in ALCL cells.

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.

Analysis of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-reactive CD8(+) T cell responses in children with NPM-ALK(+) anaplastic large cell lymphoma.

Cellular immune responses against the oncoantigen anaplastic lymphoma kinase (ALK) in patients with ALK-positive anaplastic large cell lymphoma (ALCL) have been detected using peptide-based approaches in individuals preselected for human leucocyte antigen (HLA)-A*02:01. In this study, we aimed to evaluate nucleophosmin (NPM)-ALK-specific CD8(+) T cell responses in ALCL patients ensuring endogenous peptide processing of ALK antigens and avoiding HLA preselection. We also examined the HLA class I restriction of ALK-specific CD8(+) T cells. Autologous dendritic cells (DCs) transfected with in-vitro-transcribed RNA (IVT-RNA) encoding NPM-ALK were used as antigen-presenting cells for T cell stimulation. Responder T lymphocytes were tested in interferon-gamma enzyme-linked immunospot (ELISPOT) assays with NPM-ALK-transfected autologous DCs as well as CV-1 in Origin with SV40 genes (COS-7) cells co-transfected with genes encoding the patients' HLA class I alleles and with NPM-ALK encoding cDNA to verify responses and define the HLA restrictions of specific T cell responses. NPM-ALK-specific CD8(+) T cell responses were detected in three of five ALK-positive ALCL patients tested between 1 and 13 years after diagnosis. The three patients had also maintained anti-ALK antibody responses. No reactivity was detected in samples from five healthy donors. The NPM-ALK-specific CD8(+) T cell responses were restricted by HLA-C-alleles (C*06:02 and C*12:02) in all three cases. This approach allowed for the detection of NPM-ALK-reactive T cells, irrespective of the individual HLA status, up to 9 years after ALCL diagnosis.