KIF5B-ALK, a Novel Fusion Oncokinase Identified by an Immunohistochemistry-based Diagnostic System for ALK-positive Lung Cancer

The Cancer Institute, Japanese Foundation for Cancer Research, Japan.
Clinical Cancer Research (Impact Factor: 8.72). 05/2009; 15(9):3143-9. DOI: 10.1158/1078-0432.CCR-08-3248
Source: PubMed


EML4-ALK is a transforming fusion tyrosine kinase, several isoforms of which have been identified in lung cancer. Immunohistochemical detection of EML4-ALK has proved difficult, however, likely as a result of low transcriptional activity conferred by the promoter-enhancer region of EML4. The sensitivity of EML4-ALK detection by immunohistochemistry should be increased adequately.
We developed an intercalated antibody-enhanced polymer (iAEP) method that incorporates an intercalating antibody between the primary antibody to ALK and the dextran polymer-based detection reagents.
Our iAEP method discriminated between tumors positive or negative for EML4-ALK in a test set of specimens. Four tumors were also found to be positive for ALK in an archive of lung adenocarcinoma (n = 130) and another 4 among fresh cases analyzed in a diagnostic laboratory. These 8 tumors were found to include 1 with EML4-ALK variant 1, 1 with variant 2, 3 with variant 3, and 2 with previously unidentified variants (designated variants 6 and 7). Inverse reverse transcription-PCR analysis revealed that the remaining tumor harbored a novel fusion in which intron 24 of KIF5B was ligated to intron 19 of ALK. Multiplex reverse transcription-PCR analysis of additional archival tumor specimens identified another case of lung adenocarcinoma positive for KIF5B-ALK.
The iAEP method should prove suitable for immunohistochemical screening of tumors positive for ALK or ALK fusion proteins among pathologic archives. Coupling of PCR-based detection to the iAEP method should further facilitate the rapid identification of novel ALK fusion genes such as KIF5B-ALK.

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    • ". The intercalated antibody-enhanced polymer method was used for the sensitive detection of ALK, as described previously (Takeuchi et al., 2009). "
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    ABSTRACT: Fetal lung interstitial tumor (FLIT) is a recently reported type of congenital lung lesion comprising solid and cystic components. The pathological features include unique interstitial mesenchyme-based cell proliferation, and differ from other neoplasms represented by pleuropulmonary blastoma or congenital peribronchial myofibroblastic tumor. FLIT is extremely rare and its gene expression profile has not yet been reported. We provide the first report of a novel chromosomal rearrangement resulting in α-2-macroglobulin (A2M) and anaplastic lymphoma kinase (ALK) gene fusion in a patient with FLIT. The tumor cells contained a t(2;12)(p23;p13) and were mesenchymal in origin (e.g., inflammatory myofibroblastic tumors), suggesting the involvement of ALK in this case of FLIT. Break apart fluorescence in situ hybridization demonstrated chromosomal rearrangement at ALK 2p23. Using 5'-rapid amplification of cDNA ends, we further identified a novel transcript fusing exon 22 of A2M to exon 19 of ALK, which was confirmed by reverse-transcription polymerase chain reaction. The corresponding chimeric gene was subsequently confirmed by sequencing, including the genomic break point between intron 22 and 18 of A2M and ALK, respectively. Discovery of A2M as a novel ALK fusion partner, together with the involvement of ALK, provides new insights into the pathogenesis of FLIT, and suggests the potential for new therapeutic strategies based on ALK inhibitors. © 2014 Wiley Periodicals, Inc.
    Full-text · Article · Oct 2014 · Genes Chromosomes and Cancer
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    • "The rearrangement results from a short inversion in chromosome 2p, whereby ALK signaling is activated by the creation of oncogenic fusions of the intron 10 of ALK gene within an upstream partner intron 13 of echinoderm microtubule associated protein-like 4 (EML4)6. More recently, less than 1% of ALK rearrangements cases have different partner genes including kinesin family member 5B (KIF5B), TFG, and KLC-111,18. ALK rearrangements occur in approximately 4% of lung adenocarcinoma patients, usually young, non-smokers with clinically advanced disease6,7,8. "
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    ABSTRACT: The rapid development of targeted therapies has enormously changed the clinical management of lung cancer patients over the past decade; therefore, molecular testing, such as epidermal growth factor receptor (EGFR) gene mutations or anaplastic lymphoma kinase (ALK) gene rearrangements, is now routinely used to predict the therapeutic responses in lung cancer patients. Moreover, as technology and knowledge supporting molecular testing is rapidly evolving, the landscape of targetable genomic alterations in lung cancer is expanding as well. This article will summarize the current state of the most commonly altered and most clinically relevant genes in lung cancer along with a brief review of potential future developments in molecular testing of lung cancer.
    Full-text · Article · Aug 2014 · Tuberculosis and Respiratory Diseases
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    • "Together with dimerization through the coiled-coil domain, the RET tyrosine kinase activity of the fusion protein may be activated aberrantly, thus facilitating oncogenesis in the lung. This hypothesis corroborates the oncogenic mechanism proposed for the fusion gene KIF5B-ALK, in which the coiled-coil domain of KIF5B is always preserved, and its constitutive expression in lung is believed to activate ALK and downstream oncogenic effects [30,33]. "
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    ABSTRACT: Background Lung cancer in nonsmokers tends to be driven by a single somatic mutation or a gene fusion. KIF5B-RET fusion is an oncogene identified in non-small cell lung cancers. In this study, we verified the oncogenic activity of KIF5B-RET fusion and investigated how KIF5B-RET activates the specific signaling pathways for cellular transformation. We aimed to provide a basis for the further development of the therapy for KIF5B-RET positive lung cancer patients. Methods RT-PCR was used to screen for KIF5B-RET fusions in Chinese lung cancer patients. To verify the oncogenic activity of KIF5B-RET kinase in lung cancer cells, we manipulated its expression genetically followed by colony formation and tumor formation assays. The mechanism by which KIF5B-RET kinase induces proliferation was investigated by western blot, coimmunoprecipitation, and administration of RET, MAPK and STAT3 inhibitors. Results Our study identified a KIF5B-RET fusion in Chinese NSCLC patients and demonstrated that KIF5B-RET transfected cells showed a significantly increased proliferation rate and colony-forming ability. Furthermore, we found that KIF5B-RET fusion kinase induced multilevel activation of STAT3 at both Tyr705 and Ser727, and KIF5B-RET-STAT3 signaling related inhibitors repressed the proliferation and tumorigenicity of lung cancer cells significantly. Conclusions Our data suggest that KIF5B-RET promotes the cell growth and tumorigenicity of non-small cell lung cancers through multilevel activation of STAT3 signaling, providing possible strategies for the treatment of KIF5B-RET positive lung cancers.
    Full-text · Article · Jul 2014 · Molecular Cancer
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