Anaplastic Lymphoma Kinase Antibody Research Articles

Immunohistochemical expression of anaplastic lymphoma kinase in neuroblastoma and its relations with some clinical and histopathological features.

Anaplastic lymphoma kinase (ALK) mutations have been identified as a prominent cause of some familial and sporadic neuroblastoma (NB). ALK expression in NB and its relationship with clinical and histopathological features remains controversial. This study investigated ALK expression and its potential relations with these features in NB. Ninety cases of NB at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam from 01/01/2018 to 12/31/2021, were immunohistochemically stained with ALK (D5F3) antibody. The ALK expression and its relations with some clinical and histopathological features were investigated. The rate of ALK expression in NB was 91.1%. High ALK expression (over 50% of tumor cells were positive with moderate-strong intensity) accounted for 65.6%, and low ALK expression accounted for 34.4%. All the MYCN-amplified NB patients had ALK immunohistochemistry positivity, most cases had high ALK protein expression. The undifferentiated subtype of NB had a lower ALK-positive rate than the poorly differentiated and differentiated subtype. The percentages of ALK positivity were significantly higher in more differentiated histological types of NB (p = .024). There was no relation between ALK expression and: age group, sex, primary tumor location, tumor stage, MYCN status, clinical risk, Mitotic-Karyorrhectic Index, prognostic group, necrosis, and calcification. ALK was highly expressed in NB. ALK expression was not related to several clinical and histopathological features. More studies are needed to elucidate the association between ALK expression and ALK gene status and to investigate disease progression, especially the oncogenesis of ALK-positive NB.

Abstract 2012: A humanized anaplastic lymphoma kinase (ALK)-directed antibody-drug conjugate (ADC) demonstrates potent cytotoxicity in neuroblastoma (NBL) and fusion positive rhabdomyosarcoma (FP RMS)

Abstract Introduction: ALK is a lineage restricted oncoprotein expressed on the cell surface of NBL as wild-type (WT), mutated, or amplified, and recently shown to be overexpressed in FP RMS. Small molecule inhibitors have shown potent efficacy in NBL with ALK mutations or amplifications, but is limited to a minority of the high-risk population and have demonstrated conferred resistance. We have previously shown the potential of an ADC approach for WT ALK-expressing NBL with a chimeric ALK-directed ADC CDX-0125. Methods: A highly specific humanized ALK antibody KTN0239 was developed with site-specific conjugation of an amine-azido linker conjugated to pyrrolobenzodiazepine (PBD) dimers or duocarmycin using click chemistry. ALK surface expression in ALK amplified (NB-1), WT non-amplified (IMR-32), mutant (Felix, SH-SY5Y, Kelly, NB1-643), and WT null (SK-N-AS) cell lines were quantified with flow cytometry using the primary KTN0239 antibody. Internalization kinetics of KTN0239 were measured using Incucyte® Fabflour-pH labeling. In vitro ADC IC50 values and viability rescue were assessed with a CellTiter-Glo® assay with ADC concentrations ranging from 10 fM to 10 nM. Western blot was used to elucidate cytotoxic mechanism of the ADC. Results: ALK surface protein molecule expression was 21,820 in NB-1 cells, 3,708 in Felix, and 1,426 in SK-N-AS cells. KTN0239 was internalized into NB1 cells with a logarithmic trend, with >65% of antibody internalized within 8 hours. NB-1 cell line viability was rescued to >80% when 2.5 nM of KTN0239 was in competition with the PBD-conjugated ADC at the IC50 concentration. The ADC induced activation of PARP, caspase-3, and γH2AX without attenuation of ALK signaling in NB-1 cells. Conclusions: ADCs directed to ALK-expressing cancers are a promising therapeutic approach. The efficacy of the ADCs are currently being tested in NBL and FP RMS mouse models, and will be reported. Mean IC50 values (pM) of ADCs with a drug antibody ratio (DAR) of 6 in NBL cell lines ADC: PBD-conjugated Duocarmycin-conjugated NB-1 14 71 IMR-32 12 741 Felix 51 110 NB-1643 6.6 1,196 Kelly 517 34,700 SH-SY5Y 693 3,024 SK-N-AS 533 1,420 Citation Format: Alberto D. Guerra, Annie Kennedy, Cynthia Adams, Rawan Shraim, Amber K. Weiner, Chuan Chen, Kateryna Krytska, Colleen Larmour, Smita Matkar, Dimiter Dimitrov, Dontcho V. Jelev, Yael P. Mossé. A humanized anaplastic lymphoma kinase (ALK)-directed antibody-drug conjugate (ADC) demonstrates potent cytotoxicity in neuroblastoma (NBL) and fusion positive rhabdomyosarcoma (FP RMS) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2012.

Phase-separated foci of EML4-ALK facilitate signalling and depend upon an active kinase conformation.

Variants of the oncogenic EML4‐ALK fusion protein contain a similar region of ALK encompassing the kinase domain, but different portions of EML4. Here, we show that EML4‐ALK V1 and V3 proteins form cytoplasmic foci that contain components of the MAPK, PLCγ and PI3K signalling pathways. The ALK inhibitors ceritinib and lorlatinib dissolve these foci and EML4‐ALK V3 but not V1 protein re‐localises to microtubules, an effect recapitulated in a catalytically inactive EML4‐ALK mutant. Mutations that promote a constitutively active ALK stabilise the cytoplasmic foci even in the presence of these inhibitors. In contrast, the inhibitor alectinib increases foci formation of both wild‐type and catalytically inactive EML4‐ALK V3 proteins, but not a Lys‐Glu salt bridge mutant. We propose that EML4‐ALK foci formation occurs as a result of transient association of stable EML4‐ALK trimers mediated through an active conformation of the ALK kinase domain. Our results demonstrate the formation of EML4‐ALK cytoplasmic foci that orchestrate oncogenic signalling and reveal that their assembly depends upon the conformational state of the catalytic domain and can be differentially modulated by structurally divergent ALK inhibitors.

Quantitative Multiplexed Proteomics Could Assist Therapeutic Decision Making in Non-Small Cell Lung Cancer Patients with Ambiguous ALK Test Results.

Simple SummaryTherapeutic guidance in non-small cell lung cancer (NSCLC) patients with discordant anaplastic lymphoma kinase (ALK) fluorescent in situ hybridization (+) where immunohistochemistry (IHC) (−) results are challenging. Selected reaction monitoring (SRM) quantitative multiplexed proteomics could detect ALK protein in NSCLC samples with delayed fixation where a conventional IHC method failed. ALK protein detection by the SRM method was associated with good responses on ALK inhibitors. It also could detect various predictive proteins for conventional chemotherapy at the same time, and combined results were related to clinical outcomes in this population. The SRM may provide additional information for therapeutic decision making in NSCLC patients with ambiguous ALK test results.Therapeutic guidance in non-small cell lung cancer (NSCLC) tumors that are positive for anaplastic lymphoma kinase (ALK) fluorescent in situ hybridization (FISH), but negative for ALK immunohistochemistry, is still challenging. Parallel routine screening of 4588 NSCLC cases identified 22 discordant cases. We rechecked these samples using ALK antibodies and selected reaction monitoring (SRM) quantitative multiplexed proteomics screening multiple protein targets, including ALK and MET for the ALK tyrosine kinase inhibitor (TKI), and FR-alpha, hENT1, RRM1, TUBB3, ERCC1, and XRCC1 for chemotherapy. The presence of ALK (31.8%), MET (36.4%), FR-alpha (72.7%), hENT1 (18.2%), RRM1 (31.8%), TUBB3 (72.9%), ERCC1 (4.5%), and a low level of XRCC1 (54.4%) correlated with clinical outcomes. SRM was more sensitive than the ALK D5F3 assay. Among the eight cases receiving ALK TKI, four cases with ALK or MET detected by SRM had complete or partial responses, whereas four cases without ALK or MET showed progression. Twenty-seven treatment outcomes from 20 cases were assessed and cases expressing more than half of the specific predictive proteins were sensitive to matching therapeutic agents and showed longer progression-free survival than the other cases (p < 0.001). SRM showed a potential role in therapeutic decision making in NSCLC patients with ambiguous ALK test results.

Abstract 3191: Detection of molecular drivers in inflammatory myofibroblastic tumor: study on archival tissue from EORTC 90101 “CREATE” phase II clinical trial

Abstract Background. Inflammatory myofibroblastic tumor (IMFT) is a rare mesenchymal neoplasm, mainly driven by anaplastic lymphoma kinase (ALK) rearrangement, which is present in 50% of cases and target for ALK inhibition. For the current project we used tumor material from IMFT patients treated with the ALK/ROS1/MET inhibitor crizotinib in the frame of EORTC 90101, where IMFT patients were attributed to ALK+/- sub-cohorts based on the presence (&amp;gt;15% of cells) or absence (&amp;lt;15%) of ALK rearrangement by fluorescence in situ hybridization (FISH) and/or immunohistochemistry (IHC) [Schöffski at al. Lancet Respir Med. 2018]. The aim of the project was to evaluate the frequency of ALK rearrangement, compare different methods of ALK detection, perform a detailed characterization of ALK rearrangement partners, and to identify other potential molecular drivers with potential pharmacodynamic relevance. Material and Methods. Archival material from 24 IMFT cases, both primary or metastatic samples, was analyzed by IHC using ALK antibodies: ALK1 (DAKO) and ALK-D5F3 (Cell Signalling), and pan-NTRK (Ventana, clone EPR17341). ALK and ROS1 rearrangement were studied by FISH and fusion genes were detected using the Archer CTL Fusion Panel. Results. ALK immunopositivity by ALK1 and ALK-D5F3 was observed in 14 out of 24 cases and 11/21, respectively. ALK rearrangement by FISH was found in 13/23 samples. With Archer, fusion transcripts were identified in 13/20 specimens, all but one involving ALK with 11 different fusion partners. In one case we detected an ETV6-NTRK3 fusion; NTRK positivity was confirmed by IHC. Interestingly, the NTRK fusion case responded to crizotinib, which shows cone anti-NTRK activity [Okamura et al. JCO Precis Oncol 2019]. We did not detect ROS1 rearrangement by FISH in any sample. Two samples with ALK rearrangement by Archer were negative by FISH, with 11% and 0% of cells with ALK split signal, but both showed protein expression with both antibodies used. They responded to crizotinib with either a RECIST 1.1 complete response or stable disease, for 43 and 9 months, respectively. All but one case with ALK rearrangement by Archer were positive by ALK IHC with ALK1 antibody. The only immunonegative sample had an EML4-ALK1 fusion. Two cases were positive with ALK-D5F3 antibody but no ALK positivity was detected using ALK1, and no ALK rearrangement was detected by FISH or Archer panel, suggesting false positive results. Conclusions. ALK rearrangement is the most common driver in IMFT and the fusion can involve multiple partners. ALK1 but not the ALK-D5F3 antibody shows high ALK specificity in IMFT. The Archer CTL Fusion panel is a reliable and sensitive method for detecting fusion transcripts in IMFT, also allowing to detect alternative fusion genes, which may be responsible for the sensitivity to kinase inhibitors. Citation Format: Agnieszka Wozniak, Che-Jui Lee, Tom van Wezel, Jozef Sufliarsky, Hans Gelderblom, Jean-Yves Blay, Maria Debiec-Rychter, Raf Sciot, Judith V.M.G. Bovee, Patrick Schöffski. Detection of molecular drivers in inflammatory myofibroblastic tumor: study on archival tissue from EORTC 90101 “CREATE” phase II clinical trial [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3191.

Anaplastic Lymphoma Kinase (ALK) Overexpression in Lung Cancer Biopsies - An 18 month study in north western Romania

Lung cancer is the first cause of death worldwide of oncological patients. Most of them are non-small cell lung cancer (NSCLC) and many of them are characterized by different molecular markers that allow the development of personalized treatments. Epithelial growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) are the most frequently tested genes in lung adenocarcinoma and other lung carcinomas with glandular component. The aim of our study is to evaluate the distribution of ALK gene mutation in lung cancer patient from North West part of Romania. We analysed a number of 289 lung biopsies along 18 months. The samples have been incubated with monoclonal ALK antibodies (clone D5F3), according to the manufacturer�s instruction. The interpretation guide provided by manufacturer was used to distinguish the positives vs negative cases. In our study from a total number of 289 lung biopsies, 196 cases were carcinomas. 57.65 % from the total number of lung cancers were adenocarcinomas. A total number of 79 cases have been analysed for ALK gene supra expression. 5.08 % of adenocarcinomas were positive for ALK, but the mean age for this population is higher comparing with the data from other studies.

Anaplastic lymphoma kinase 5A4 immunohistochemistry as a diagnostic assay in lung cancer: A Canadian reference testing center's results in population-based reflex testing.

The presence of anaplastic lymphoma kinase (ALK) rearrangement predicts response to ALK tyrosine kinase inhibitor (TKI) therapy. Fluorescence in situ hybridization (FISH) was the initial reference standard to detect ALK rearrangement, but immunohistochemistry (IHC) using D5F3 has gained acceptance as an alternative diagnostic method. ALK IHC assays using other ALK antibodies have also been used as screening methods, but data supporting their utility as diagnostic tests have not been widely reported. Data from reflexive clinical ALK IHC test using the 5A4 clone concurrent with epidermal growth factor receptor (EGFR) mutation testing were analyzed. ALK IHC results were reported as negative (-), equivocal, or positive (+), with equivocal or positive staining validated by FISH break-apart probe testing. Treatment outcomes were reviewed for ALK IHC+ patients. Between 2012 and 2015, 146 (2.5%) cases were reported as ALK IHC+, 188 (3.2%) were reported as equivocal, and 5624 (94.4%) were reported as ALK IHC-. Of the ALK IHC+ cases, 131/143(91.6%) were ALK FISH+. Excluding 6 cases in which FISH was inconclusive or not performed, the positive predictive value was 95.6%, and the negative predictive value was 100%. Most specimens (n=5352 [89.6%]) were also successfully tested for EGFR. Clinical responses to ALK TKIs were noted in 49 ALK IHC+ patients, with a median progression-free survival of 9.9months. ALK 5A4 IHC can serve as a robust diagnostic test for ALK-rearranged lung cancer and is associated with treatment response and survival. Optimized tissue allocation resulted in high success rates of combined reflex EGFR and ALK testing.

Epidermal growth factor receptor and anaplastic lymphoma kinase mutation in adenocarcinoma lung: Their incidence and correlation with histologic patterns.

Epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutational analysis in adenocarcinoma lung are growing in importance as these tests are essential in guiding the use of targeted therapy. However, the prevalence of these mutations in various populations in India has not been studied. Furthermore, the correlation of histologic pattern with the mutation is not clear. A total of 64 biopsy-proven lung adenocarcinomas were selected. In 51 of these, EGFR mutational analysis was performed using Qiagen EGFR pyrosequencing kit and in 56 cases of these ALK1 immunohistochemistry (IHC) was done using ALK (D5F3) antibody and the Ventana Benchmark® XT automated IHC slide staining system for the detection of overexpression. The adenocarcinomas were classified into well, moderate, and poorly differentiated, and the histological pattern was recorded according to the WHO 2014 classification. EGFR mutation was positive in 23 cases (45.10%) and positive ALK1 expression by IHC in 12 cases (21.43%). Both mutations were positive in two cases. Both mutations were seen in well-differentiated and moderately differentiated adenocarcinoma, and the expression was highest in tumors with a predominant acinar pattern. The incidence of both EGFR and ALK1 mutations is higher in the population studied and seem to correlate with a well differentiated, acinar pattern on morphology.

ALK (D5F3) CDx: an immunohistochemistry assay to identify ALK-positive NSCLC patients.

Screening for anaplastic lymphoma kinase (ALK) rearrangements is a very important process in treatment decision making for advanced non-small-cell lung cancer (NSCLC). Although fluorescent in situ hybridization (FISH) is considered the universally accepted reference standard, it is associated with technical difficulties and high costs that have made global implementation of this assay challenging. Conversely, ALK immunohistochemistry has shown high sensitivity and specificity compared to FISH and other molecular assays and is more cost-effective. In fact, the ALK (D5F3) CDx immunohistochemistry assay was approved by the US Food and Drug Administration as a standalone test for ALK rearrangements in lung cancer in 2015. In this review, we will discuss the overview of ALK rearrangements in NSCLC, various testing methods for ALK rearrangements, and the details of immunohistochemistry for ALK, in particular one with the ALK antibody clone D5F3.

Epitope mapping of anti-ALK antibodies in children with anaplastic large cell lymphoma

Patients with Nucleophosmin (NPM)-Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) mount ALK autoantibodies. The titer of these autoantibodies inversely correlates with the risk of relapse.The epitopes recognized by these autoantibodies in NPM-ALK might be associated with different ALK-antibody levels. We used overlapping peptide microarray technology to analyze epitope-binding to NPM-ALK by plasma or serum from 129 ALK-positive ALCL patients and 21 controls. Antibodies present in sera from ALCL patients bound to epitopes mainly in the C-terminal region of the ALK portion of NPM-ALK (amino acid positions 469–496, 561–588, 617–644). Patients with higher ALK antibody titers detected the epitope 561–588 more frequently as well as three further epitopes at the N-terminus of the kinase domain compared to patients with intermediate and low titers.These results identify new potential target epitopes for immunotherapy in ALK-positive ALCL. The methodology can be adapted for more reproducible analyses of tumor antigen detection.

Epitope mapping of spontaneous autoantibodies to anaplastic lymphoma kinase (ALK) in non-small cell lung cancer.

The anaplastic lymphoma kinase (ALK) is recognized by the immune system as a tumor antigen, and preclinical evidence suggests that ALK-rearranged NSCLCs can also be successfully targeted immunologically using vaccine-based approaches. In contrast to ALK-rearranged lymphomas, the frequency and clinical significance of spontaneous ALK immune responses in patients with ALK-rearranged NSCLCs are largely unknown. We developed an enzyme-linked immunosorbent assay (ELISA) to measure anti-ALK antibody levels and mapped specific peptide epitope sequences within the ALK cytoplasmic domain in patients with non-small cell lung cancer. The ELISA method showed good correlation with ALK antibody titers measured with a standard immunocytochemical approach. Strong anti-ALK antibody responses were detected in 9 of 53 (17.0%) ALK-positive NSCLC patients and in 0 of 38 (0%) ALK-negative NSCLC patients (P<0.01), and the mean antibody levels were significantly higher in ALK-positive than in ALK-negative NSCLC patients (P=0.02). Across individual patients, autoantibodies recognized different epitopes in the ALK cytoplasmic domain, most of which clustered outside the tyrosine kinase domain. Whether the presence of high ALK autoantibody levels confers a more favorable prognosis in this patient population warrants further investigation.

ALK immunohistochemistry for ALK gene rearrangement screening in non-small cell lung cancer: a systematic review and meta-analysis.

The aim of this study was to investigate the diagnostic accuracy of anaplastic lymphoma kinase (ALK) immunohistochemistry (IHC) for ALK gene rearrangement in non-small cell lung cancer (NSCLC) through systematic review, meta-analysis and diagnostic test accuracy review. The current study included 11,806 NSCLC cases in 42 eligible studies. We performed concordance analyses between ALK IHC and fluorescence in situ hybridization (FISH). The diagnostic accuracy of ALK IHC was analyzed based on ALK IHC criteria and antibodies. The overall ALK IHC results were positive in 13.2%. The overall concordance rate between ALK IHC and FISH was 0.950 (95% confidence interval [CI], 0.927-0.966). In the ALK IHC-positive and negative groups, the concordance rates were 0.805 (95% CI 0.733-0.861) and 0.985 (95% CI 0.978-0.990), respectively. The ALK FISH-positive rates were 0.009 (95% CI 0.004-0.023), 0.378 (95% CI 0.217-0.572), 0.628 (95% CI 0.420-0.796) and 0.900 (95% CI 0.840-0.939) in the ALK IHC 0, 1+, 2+ and 3+ groups, respectively. In diagnostic test accuracy review for ALK IHC, the pooled sensitivity and specificity were 0.92 (95% CI 0.89-0.94) and 0.91 (95% CI 0.90-0.91), respectively. The diagnostic odds ratio and the area under the curve on the summary receiver operating characteristic curve were 266.56 (95% CI 110.83-641.14) and 0.983, respectively. Our results suggested that ALK IHC equivocal (score 1+ and 2+) cases should not be considered as IHC-negative in screening for ALK gene rearrangement. Additional detailed criteria for ALK IHC equivocal cases are necessary to determine how to best apply this approach in daily practice.

Abstract 415: A new, highly sensitive ALK antibody improves the screening of rearranged-ALK by IHC

Abstract All non-small cell lung cancer (NSCLC) patients are recommended to be screened for anaplastic lymphoma kinase (ALK)-rearrangement despite its low occurrence (&amp;lt; 7%). This is due to recent advances in treatment for patients with ALK-positive NSCLC with receptor tyrosine kinase inhibitors Crizotinib and Ceritini. Current rearranged-ALK testing includes fluorescence in situ hybridization (FISH), reverse transcription polymerase chain reaction (RT-PCR), and immunohistochemistry (IHC). Despite the high sensitivities and specificities, the limitations of the first two assays include time-consuming, infeasible, and specialized techniques that make them unsuitable for the routine screening for which IHC has been proposed. However, the biggest obstacle to detecting rearranged-ALK in lung cancer patients by IHC is the lack of highly sensitive ALK antibodies that detect the extremely low abundance of ALK in patients. To overcome this limitation, we have developed an ALK mouse monoclonal antibody (clone OTI1A4) with higher sensitivity in comparison to a rabbit ALK antibody (clone D5F3). Moreover, OTI1A4 identified ALK-positive NSCLC samples (16/16 cases) and showed negative staining for ALK-negative samples (11/11 cases) previously validated by FISH (10/16 ALK-positive cases) or qPCR (10/16 ALK-positive cases). This indicated the potential advantage of using clone OTI1A4 over FISH or qPCR to detect ALK rearrangements. Lastly, there was 100% concordance between OTI1A4 and D5F3 in detecting ALK-rearranged NSCLC samples previously confirmed by FISH (76 ALK-positive and 438 ALK-negative samples). These results support the possibility that ALK clone OTI1A4 could be used for routine screening of patients with ALK-positive NSCLC by IHC. Citation Format: Hsiangmin Lu, Rachel Gonzalez, Yi Shen, Mu-lan Jin, Yipan Wu, Yungang Zhang, Kehu Yuan, Boyang Chu, Lili Qi, Huibo Liu, Chenlin Wang, Guangli Wang, Youmin Shu, Julie McDowell, Donghui Ma, Wei-wu He, Jian Chen, Ray Lin. A new, highly sensitive ALK antibody improves the screening of rearranged-ALK by IHC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 415.

NPM-ALK Mediated Tyrosine Phosphorylation of ATP Citrate Lyase Regulates Lipid Metabolism and Promotes Oncogenesis of Anaplastic Large Cell Lymphoma

Introduction: Anaplastic large cell lymphoma (ALCL) is characterized by recurrent translocations involving anaplastic lymphoma kinase (ALK) and resulting in oncogenic chimeric fusion tyrosine kinases such as NPM-ALK. We integrated mass-spectrometry-driven phosphoproteomics and metabolomics of ALK+ ALCL and discovered that ATP citrate lyase (ACLY) is a candidate substrate of NPM-ALK at residue Y682. ACLY is a critical enzyme responsible for synthesis of acetyl-CoA and connects vital biosynthetic pathways such as carbohydrate and lipid metabolism. Functional regulation of ACLY by tyrosine phosphorylation is unknown and the significance of tyrosine phosphorylation of ACLY on cancer cell growth and metabolism have never been described.Methods: To identify novel substrates of NPM-ALK, we performed phospho-proteomic analyses of 3 ALK+ALCL derived cell lines. The MS-phosphoproteomic data were subjected to custom bioinformatic algorithms to identify highly statistically correlated phosphotyrosine proteins and phosphosites regulated by ALK kinase activity. We generated a phosphospecific antibody against a highly-ranked candidate (pACLY Y682) and utilized it in western blot analyses on ALK+ and ALK- ALCL lymphoma cell lines. Immunohistochemistry (IHC) on well-characterized primary human ALK+ (n=20) and ALK-ALCL biopsies (n=28) were performed. Co-immunoprecipitations (Co-IP) with HA-tagged ACLY-WT and ACLY-Y682F and ALK antibodies were performed and analyzed by western blot using the pACLY Y682 antibody. In vitro kinase assays were performed to investigate the direct role of NPM-ALK in phosphorylation of ACLY at Y682 using GST-tagged ACLY-WT or ACLY-Y682F peptides in the presence or absence of immunocomplexes containing active NPM-ALK or the kinase-defective K210R mutant. To study the impact of Y682F mutant on lipid metabolism, we generated ALCL-derived cell lines stably transduced to express GFP-tagged ACLY-WT or ACLY-Y682F and subjected them to metabolomic analysis for flux, β-oxidation or lipid synthesis using liquid chromatography/tandem mass spectrometry or gas chromatography platforms. The Seahorse XF24 Flux analyzer was used to measure oxygen consumption rates (OCR) in DEL stably expressing ACLY-WT and ACLY-Y682F. Cells stably expressing ACLY-WT and ACLY-Y682F were evaluated for cell proliferation, colony formation and tumor formation in SCID-BEIGE mouse xenograft models.Results: Phosphoproteomic analyses yielded a dataset containing a total of 626 tyrosine phosphoproteins. Bioinformatic analysis identified pACLY Y682 as a novel candidate substrate of NPM-ALK. Western blot analysis corroborated phosphoproteomic studies and demonstrated that phosphorylation of ALCY at Y682 is regulated by NPM-ALK activity. Expression of active NPM-ALK increased the phosphorylation of ACLY at Y682 in HEK293T cells compared to the K210R mutant. In vitro kinase assays demonstrated that NPM-ALK phosphorylates ACLY at Y682. Immunoprecipitation (IP) of ALK and co-IP (HA) demonstrated interaction of NPM-ALK and ACLY in co-transfected HEK293T cell lysates. Stable expression of ACLY-Y682F or pharmacologic antagonism of ALK with crizotinib resulted in decreased ACLY activity, decreased lipid synthesis and increased fatty acid β-oxidation when compared to ACLY-WT. β-oxidation of 13 C-oleic acid-labeled fatty acid demonstrated increased labeling of +2-citrate (p<0.01) and +18-Oleyol carnitine (p<0.001) in ACLY-Y682F cells when compared to ACLY-WT. Similarly, the OCR was significantly increased in cells expressing ACLY-Y682F (p<0.001). IHC studies of ALCL biopsies (ALK+ and ALK-) demonstrated significant correlation between NPM-ALK and ACLY pY682- expression (p<0.01). Expression of ACLY-Y682F in the DEL cell line resulted in dramatically decreased cell proliferation, impaired clonogenic potential as observed by small colony size in colony formation assay and abrogated tumor growth in in vivo xenograft model when compared to ACLY-WT.Conclusion: We identify for the first time a direct tyrosine kinase-mediated mechanism for ACLY regulation. In this regard, our studies demonstrate a novel oncogenic mechanism whereby NPM-ALK controls lipid synthesis and b-oxidation by phosphorylation of ACLY at Y682 and this mechanism contributes to ALCL pathogenesis. Our findings have significant implications for novel therapies targeting tumor metabolism in ALCLs. DisclosuresNo relevant conflicts of interest to declare.

Comparing four different ALK antibodies with manual immunohistochemistry (IHC) to screen for ALK -rearranged non-small cell lung cancer (NSCLC)

Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) screening is essential to its treatment such as crizotinib. Different assays have been developed to detect ALK rearrangements, such as fluorescence in situ hybridization (FISH), reverse transcriptase-PCR (RT-PCR), and immunohistochemistry (IHC). However, ALK detection has not been applied widely in all hospitals. Moreover, IHC has been proposed to be a pre-screening tool because of its wide application in clinics. Since the low expression of ALK protein, the sensitivity and specificity of ALK antibody are the keys to the success of IHC screening. Therefore, we compared different antibodies to find the best one for IHC detection. We evaluated ALK expression by four different ALK antibodies: clone D5F3 (Ventana), clone D5F3 (CST), clone 1A4/1H7 (OriGene Tech.), and clone 5A4 (Abcam) based on manual IHC in a cohort of 60 NSCLCs. The results were compared with those from automated IHC (clone D5F3, Ventana). All cases were evaluated independently by ALK FISH. 32 ALK-positive and 28 ALK-negative NSCLCs were identified by automated IHC (D5F3, Ventana) and FISH analysis. Based on conventional manual IHC, the sensitivity of four antibodies-D5F3 (Ventana), D5F3 (CST), 1A4/1H7 (OriGene Tech.), and 5A4 (Abcam)-was 93.8%, 84.4%, 93.8%, and 56.3%, respectively. Their specificities and positive predictive values were 100%. The percentage of strong-moderate staining was 65.6%, 62.5%, 68.8%, and 21.9%, respectively. Compared with automated IHC (D5F3, Ventana), each staining concordance was 96.7%, 91.7%, 96.7%, and 76.7%, respectively, and each presented staining heterogeneity (weak-moderate-strong intensity). These data indicated that manual IHC with a more reliable ALK antibody might provide an effective strategy for screening ALK gene rearrangements in all NSCLC patients, followed by confirmatory FISH analysis in IHC-positive cases.

Comparison of Methods in the Detection of ALK and ROS1 Rearrangements in Lung Cancer

The use of targeted therapies toward specific oncogenic driver mutations has become a critical factor in the treatment of patients with lung cancer. It is therefore essential to utilize tests with high performance characteristics. Fluorescence in situ hybridization (FISH) is the standard method for detecting anaplastic lymphoma kinase (ALK) and ROS1 rearrangements in non-small-cell lung cancer but the utility of other methods such as immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) is unclear. Three hundred and sixty-two lung cancer patients were tested with FISH, CISH, and IHC using three ALK antibodies (ALK1, 5A4, D5F3) and one ROS1 antibody in the detection of ALK and ROS1 rearrangements. There was a 97.4% concordance (298 of 306) between FISH and CISH for detection of ALK rearrangements. The ROS1 rearrangement status had a 97% (291 of 300) concordance between CISH and FISH. ALK protein expression was observed in 6 of 341 samples with the ALK1 and 5A4 antibodies and 5 of 341 samples with D5F3. All three antibodies stained each of the ALK FISH-positive samples (100% sensitivity). ROS1 protein expression was observed in 2 of 322 samples. One of three samples with a ROS1 rearrangement by FISH showed ROS1 protein expression (33.3% sensitivity). Our findings show good correlation between FISH versus CISH in the detection of ALK and ROS1 rearrangements. FISH versus IHC showed good correlation in the detection of ALK rearrangements but showed weak correlation in the detection of ROS1 rearrangements. These results suggest CISH and IHC could be complimentary detection methods to FISH in the detection of ALK and ROS1 rearrangements.

Cytology specimens offer an effective alternative to formalin‐fixed tissue as demonstrated by novel automated detection for ALK break‐apart FISH testing and immunohistochemistry in lung adenocarcinoma

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC). ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases). The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH. The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC.

Anaplastic Lymphoma Kinase (ALK1) Immunohistochemistry in Diagnostic Dermatopathology; An Update

The use of anaplastic lymphoma kinase antibodies (ALK1) as a diagnostic aid has expanded since becoming a routinely available immunohistochemical stain. Because the skin may be the site of a wide variety of hematolymphoid and fibroblastic proliferations, dermatopathologists commonly use ALK1 as part of a broader staining panel in diagnosing soft tissue and cutaneous hematolymphoid neoplasms. Furthermore, new entities and differential diagnostic contexts are emerging, which broaden the utility of ALK1 immunohistochemistry. We review the expanding role of ALK1 immunohistochemistry in contemporary dermatopathology.

Antibody targeting of anaplastic lymphoma kinase induces cytotoxicity of human neuroblastoma

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in neuroblastoma, a devastating pediatric cancer of the sympathetic nervous system. Germline and somatically acquired ALK aberrations induce increased autophosphorylation, constitutive ALK activation and increased downstream signaling. Thus, ALK is a tractable therapeutic target in neuroblastoma, likely to be susceptible to both small-molecule tyrosine kinase inhibitors and therapeutic antibodies-as has been shown for other receptor tyrosine kinases in malignancies such as breast and lung cancer. Small-molecule inhibitors of ALK are currently being studied in the clinic, but common ALK mutations in neuroblastoma appear to show de novo insensitivity, arguing that complementary therapeutic approaches must be developed. We therefore hypothesized that antibody targeting of ALK may be a relevant strategy for the majority of neuroblastoma patients likely to have ALK-positive tumors. We show here that an antagonistic ALK antibody inhibits cell growth and induces in vitro antibody-dependent cellular cytotoxicity of human neuroblastoma-derived cell lines. Cytotoxicity was induced in cell lines harboring either wild type or mutated forms of ALK. Treatment of neuroblastoma cells with the dual Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth inhibition by promoting cell surface accumulation of ALK and thus increasing the accessibility of antigen for antibody binding. These data support the concept of ALK-targeted immunotherapy as a highly promising therapeutic strategy for neuroblastomas with mutated or wild-type ALK.

Testing for anaplastic lymphoma kinase (ALK) rearrangement in lung adenocarcinomas: a multicentre study

Aims Non-small cell lung cancer (NSCLC) has the highest cancer-related mortality globally. Rearrangements of ALK in NSCLCs define a subgroup of patients with specific clinical, pathological and molecular characteristics and are associated with sensitivity to an ALK/MET inhibitor, with promising response rates. We aimed to assess the clinical utility of ALK translocation screening and to identify the frequency and clinicopathological features of lung adenocarcinomas harbouring ALK translocations, using immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH). Methods NSCLC tissue was obtained from patients treated at the Royal Prince Alfred Hospital and Concord Repatriation Hospital, Sydney, and St Vincent’s Hospital and Peter MacCallum Cancer Centre, Melbourne, with a total of 666 cases evaluated. Tissue microarrays were screened using ALK IHC (Clone ALK-1, Dako; Clone 5A4, Novocastra) and ALK break-apart translocation FISH (Abbott Molecular). Results ALK rearrangements were found in six cases (1%) by FISH, which is comparatively lower than other reported frequencies. The 5A4 ALK antibody identified all six ALK positive cases (100% sensitivity). One false negative resulted from the ALK-1 antibody (86% sensitivity). Conclusions We believe ALK IHC represents an effective means of routinely screening selected NSCLC patients for ALK rearrangement testing using FISH.