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Anaplastic lymphoma kinase (ALK) fusion variants in non-small-cell-lung cancer (NSCLC) consist of numerous dimerising fusion partners, with the most common being EML4. Clinical data suggests that the degree of treatment benefit in response to ALK tyrosine kinase inhibitors (TKIs) differs among the variant present in the patient tumor. Therefore, a better understanding the oncogenic signaling networks driven by different ALK-fusion variants is important. Here, we developed highly controlled doxycycline-inducible cell models bearing four different ALK fusion proteins, namely EML4-ALK-V1, EML4-ALK-V3, KIF5B-ALK, and TFG-ALK, in the context of non-tumorigenic NL20 human bronchial epithelial cells. These were complimented by patient-derived NSCLC cell lines harboring either EML4-ALK-V1 or EML4-ALK-V3 fusions. RNA-seq and phosphoproteomics analysis were employed to identify dysregulated genes and hyper/hypo-phosphorylated proteins associated with ALK fusion expression. Among ALK fusion induced responses, we noted a robust inflammatory signature that included up-regulation of the Serpin B4 serine protease inhibitor in both NL20-inducible cell models and ALK-positive NSCLC patient-derived cell lines. We show that STAT3 is a major transcriptional regulator of SERPINB4 downstream of ALK fusions, along with NF-kB and AP1. The upregulation of SERPINB4 promotes survival of ALK fusion expressing cells and inhibits natural killer (NK) cell-mediated cytotoxicity. In conclusion, our study reveals a novel ALK downstream survival axis that regulates Serpin B4 expression and identifies a molecular target that has potential for therapeutic impact targeting the immune response together with ALK TKIs in NSCLC. Citation Format: Tzu-Po Chuang, Wei-Yun Lai, Jonatan L. Gabre, Dan E. Lind, Ganesh Umapathy, Abdulmalik A. Bokhari, Bengt Bergman, Linnea Kristenson, Fredrik B. Thorén, Anh Le, Robert Doebele, Jimmy V. Eynden, Ruth H. Palmer, Bengt Hallberg. ALK fusion oncogene driven SERPINB4 expression enhances tumor survival in NSCLC. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3936.

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

The RAS-RAF-MEK-ERK pathway is a major player in initiation and progression of multiple cancers where it can be hyperactivated by upstream regulatory proteins, such as tyrosine kinases, phosphatases, and GTPases. Several inhibitors targeting the RAS-MAPK pathway exhibit anticancer activity and are approved as single agent in specific cancers. One such is the MEK inhibitor trametinib, which is included as a rational polytherapy strategy for treating EML4-ALK, EGFR, and K-RAS mutant lung cancer and neuroblastoma containing hyperactivating RAS-MAPK pathway mutations. In neuroblastoma, a heterogeneous disease, relapse cases display an increased rate of mutations of ALK, NRAS, and NF1 genes, leading to hyperactivation of RAS-MAPK signaling. Targeting the RAS-MAPK pathways offers attractive options for combinatorial treatment together with ALK inhibitors, since monotreatment has not yet produced strong clinical results in ALK-positive neuroblastoma patients. Here we investigate the response of ALK-positive neuroblastoma cell lines to MEK inhibition, employing trametinib. We show that pharmacologic inhibition of the MEK-ERK pathway in ALK-positive neuroblastoma cells results in increased levels of activation/phosphorylation of AKT and ERK5. This feedback response is regulated by the mTORC2 complex protein SIN1. Taken together, our results indicate that blocking MEK-ERK leads to increased activation of AKT signaling core in ALK-positive neuroblastoma, intensifying survival signals in these cells. Our results contraindicate use of MEK inhibitors as an effective single- and polytherapeutic strategy in ALK-positive neuroblastoma. Citation Format: Bengt Hallberg, Ganseh Umapathy, Jikui Guan, Dan Gustafsson, Niloufar Javanmardi, Diana Cervantes-Madrid, Anna Djoos, Tommy Martinsson, Ruth Palmer. Anaplastic lymphoma kinase addicted neuroblastoma cell lines are associated with growth upon treatment with MEK inhibitor trametinib [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr B27.

Background: The protein kinase B (PKB/AKT) and RAF/MEK/ERK signaling pathways are activated in a wide range of human cancer types. In many cases, concomitant inhibition of both pathways is necessary to block proliferation and induce cell death and tumor shrinkage. Several feedback mechanisms have been described in which inhibition of one pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of targeted monotherapies. Materials and Methods: In order to determine which signalling core should be blocked for combinatorial treatment, we treated a panel of EML4-ALK positive lung cancer cell lines using MEK-ERK inhibitors. Resazurin assay was performed to evaluate cell viability. Protein levels were determined using western blotting. Results: In this study, we describe a feedback mechanism in which MEK-ERK inhibition leads to increased activation of AKT signaling in EML4-ALK variant (E6a/b;A20) positive NSCLC cell lines. Interestingly, EML4-ALK variant (E13;A20) NSCLC cell lines responds to MEK-ERK inhibitors and shows synergism when combined with ALK tyrosine kinase inhibitors. We found that feedback response in EML4-ALK variant (E6a/b;A20) positive NSCLC cells was mediated by the mammalian target of rapamycin complex 2-associated protein SIN1, resulting in increased survival and proliferation that depended on AKT signaling. Conclusions: Taken together, these results elucidate an important feedback network and contraindicate the use of MEK inhibitors as effective therapeutic strategy in EML4-ALK variant (E6a/b;A20) positive NSCLC. Citation Format: Bengt Hallberg, Ruth H. Palmer, Ganesh Umapathy, Dan E. Gustafsson, Joachim T. Siaw, Wasi Alam, Jikui Guan, Robert Doebele, Anh T. Le, Andrea Doak. EML4-ALK variant E6a/b;A20 positive NSCLC cell lines are associated with growth upon blocking MEK-ERK pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5785.

Mutations in the kinase domain of Anaplastic Lymphoma Kinase (ALK) have been suggested to be important players in the genetics and progression of the childhood tumor neuroblastoma. Here we report the appearance of a novel ALK mutation in neuroblastoma together with other chromosomal aberrations that mediate neuroblastoma initiation and progression. Analyses of genomic tumor DNA from biopsy samples initially showed an 11q minus, 17q gain with a mutation of the ALK gene at protein position 1171, which mediate an amino acid change from isoleucine to threonine. We show that mutation of I1171 to threonine generates a potent gain-of-function mutant, as observed in two independent systems. Firstly, in PC12 cell lines expressing ALKI1171T display ligand independent activation of ALK, neurite outgrowth and further downstream signaling activation. Secondly, ALKI1171T meditate foci formation in a NIH3T3 transformation analysis. Finally, pharmacological inhibition of ALKI1171T employing ceritinib, an FDA approved ALK inhibitor show 14-fold better ability to abrogate ALKI1171T compared with crizotinib. Citation Format: Joachim T. Siaw, Jikui Guan, Tommy Martinsson, Magnus Hansson, Per Kogner, Ruth Palmer. A novel activating I1171T ALK mutation in neuroblastoma responds better to ceritinib compare to the first generation inhibitor crizotinib [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr B40.

ALK inhibitors such as the ALK/MET/ROS1 inhibitor crizotinib (Xalkori) have shown clinical efficacy in a number of tumour types. However, in ALK positive neuroblastoma treatment with the ALK inhibitor crizotinib has proved more difficult, highlighting the exploration of new drugs as a clinical priority. A recent report of an increased percentage of ALK positive cases in the relapsed neuroblastoma patient population, together with the increased repertoire of ALK inhibitors now available, led to the investigation of alternative ALK inhibitors with potential for use in treatment of neuroblastoma. Here we report an investigation of the activity of a next generation ALK inhibitor in a range of in vitro and pre-clinical ALK driven neuroblastoma models. Initially PF-06463922 was tested in various neuroblastoma cell lines and a range of gain-of-function ALK neuroblastoma mutations were subsequently analyzed in more detail in engineered Ba/F3 and PC12 cell models and by in vitro kinase assays, comparing the effect of PF-06463922 in abrogating cell growth and induced pharmacodynamics markers of response with the ALK inhibitor crizotinib. These results clearly show PF-06463922 to be a superior inhibitor of ALK kinase activity inhibiting all neuroblastoma mutant ALK forms assayed. Finally, single agent oral administration of PF-06463922 lead to induction of apoptosis and a dramatic reduction in tumour volume in a genetically engineered mouse model of treatment-resistant high-risk neuroblastoma driven by aberrant expression of MYCN and activated ALK. Taken together, our results suggest that PF-06463922 represents an important potential step forward in the treatment of relapsed neuroblastoma with mutated ALK. Statement of significance: Our results together with PK/PD analysis of PF-06463922 suggest future clinical trial investigation of ALK positive neuroblastoma Citation Format: J. Guan, L. Danielson, D. Chand, Y. Jamin, K. Ruuth, E. Tucker, G. Umapathy, A. El Wakil, B. Witek, T. W. Johnson, T. Smeal, L. Chesler, R. H. Palmer, B. Hallberg. The ALK inhibitor PF-06463922 shows significant response as a single agent in ALK/MYCN driven models of neuroblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B12.

Mutations in the kinase domain of the ALK kinase have emerged recently as important players in the genetics of the childhood tumor neuroblastoma. Here, we report the appearance of a novel ALK mutation in neuroblastoma, correlating with aggressive tumor behavior. Analyses of genomic DNA from biopsy samples initially showed ALK sequence to be wild type. However, during disease progression, mutation of amino acid F1174 to a serine within the ALK kinase domain was observed, which correlated with aggressive neuroblastoma progression in the patient. We show that mutation of F1174 to serine generates a potent gain-of-function mutant, as observed in 2 independent systems. First, PC12 cell lines expressing ALKF1174S display ligand-independent activation of ALK and further downstream signaling activation. Second, analysis of ALKF1174S in Drosophila models confirms that the mutation mediates a strong, rough eye phenotype upon expression in the developing eye. Thus, we report a novel ALKF1174S mutation that displays ligand-independent activity in vivo, correlating with rapid and treatment-resistant tumor growth. The study also shows that initial screening in the first tumor biopsy of a patient may not be sufficient and that further molecular analysis, in particular in tumor progression and/or tumor relapse, is warranted for better understanding of the treatment of neuroblastoma patients. Cancer Res; 71(1); 98–105. ©2011 AACR.

Neuroblastoma (NBL) is a cancer of early childhood arising from the developing sympathetic nervous system. NBL tumors display a broad clinical and biological heterogeneity, ranging from highly aggressive tumors with fatal outcome to tumors with spontaneous regression. Recurrent mutations are mainly only observed in Anaplastic Lymphoma Kinase (ALK), which is involved in the pathogenesis of both familiar and sporadic NBL. ALK encodes a tyrosine kinase receptor with importance in neuronal development and was initially characterized in anaplastic large cell lymphoma from a translocation leading to the NPM-ALK fusion protein. Subsequent studies show that additional ALK chimeras have been generated with different fusion partners in various cancers. To date no ALK-containing rearrangement has been reported in primary NBL tumors although one study has described a NBL cell line with an ALK intragenic deletion leading to constitutive ALK kinase activity. This led us to screen for and further investigate possible ALK containing translocations in our NBL material. Genomic profiling of 350 NBL samples though SNP microarrays indicated ALK-rearrangement in four primary tumors and two cell lines (IMR32 and CLB-BAR) which were further analyzed through targeted re-sequencing of the common MYCN amplicon region (Chr2;14-18Mb) and the entire ALK gene. Briefly, detection of rearrangements was performed through solution-based enrichment followed pair-end sequencing of 400-500bp libraries. Junction sites were identified by manual sequence viewing on IGV and validated through PCR followed by Sanger sequencing. With this strategy we were able to determine translocation sites for all but one sample. In one tumor ALK was found to be translocated to GAB2 (chr11q14) causing loss of the first exon of respective gene. However, ALK and GAB2 were placed head-to-head with respect to transcription direction and this novel translocation is therefore unlikely to cause a chimeric protein. Another tumor showed translocation between ALK intron 4 and chr 4 subtelomeric region without known genes. Two NBL cell lines and one tumor had both MYCN and ALK amplification and sequencing revealed high level complexity of respective amplicon with multiple rearrangements. IMR32 show involvement of at least six different 2p-regions including MYCN and ALK exon 3-4. CLB-BAR has also multiple rearrangements including an ALK intragenic translocation causing loss of exon 4-11, ultimately resulting in an ALK protein with truncated extracellular domain. Here we show that ALK translocation sites could be deduced from targeted re-sequencing without previous knowledge about fusion partner. However, no translocations resulting in chimeric protein were detected. We were also able to detect MYCN amplicon junctions, which are highly unique for each patient and could be used for detection of minimal residual disease. Citation Format: Susanne M. Fransson, Anna Djos, Niloufar Javanmardi, Rosa Noguera, Ana Berbegall, Magnus Hansson, Per Kogner, Kristina Ruuth, Ruth Palmer, Bengt Hallberg, Tommy Martinsson. Targeted re-sequencing of neuroblastoma tumors reveals chromosomal rearrangements that involve the Anaplastic Lymphoma Kinase (ALK) gene. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4107. doi:10.1158/1538-7445.AM2013-4107