A Care Robot with Ethical Sensing System for Older Adults at Home.

Many studies have explored emotional and mental services that robots can provide for older adults, such as offering them daily conversation, news, music, or health information. However, the ethical issues raised by using sensors for frail older adults to monitor their daily movements or their medication intake, for instance, are still being discussed. In this study, we develop an older adult-guided, caregiver-monitored robot, Dori, which can detect and recognize movement by sensing human poses in accordance with two factors from the human-centered artificial intelligence (HCAI) framework. To design the care robot's services based on sensing movement during daily activities, we conducted focus group interviews with two groups-caregivers and medical staff-on the topic of care robot services not for patients but for prefrail and frail elderly individuals living at home. Based on their responses, we derived the focal service areas of cognitive support, emotional support, physical activity support, medication management, and caregiver management. We also found the two groups differed in their ethical judgments in the areas of dignity, autonomy, controllability, and privacy for services utilizing sensing by care robots. Therefore, the pose recognition technology adopted in the present work uses only joint coordinate information extracted from camera images and thus is advantageous for protecting human dignity and personal information.

Transforming mutations of RAC guanosine triphosphatases in human cancers.

Members of the RAS superfamily of small guanosine triphosphatases (GTPases) transition between GDP-bound, inactive and GTP-bound, active states and thereby function as binary switches in the regulation of various cellular activities. Whereas HRAS, NRAS, and KRAS frequently acquire transforming missense mutations in human cancer, little is known of the oncogenic roles of other small GTPases, including Ras-related C3 botulinum toxin substrate (RAC) proteins. We show that the human sarcoma cell line HT1080 harbors both NRAS(Q61K) and RAC1(N92I) mutant proteins. Whereas both of these mutants were able to transform fibroblasts, knockdown experiments indicated that RAC1(N92I) may be the essential growth driver for this cell line. Screening for RAC1, RAC2, or RAC3 mutations in cell lines and public databases identified several missense mutations for RAC1 and RAC2, with some of the mutant proteins, including RAC1(P29S), RAC1(C157Y), RAC2(P29L), and RAC2(P29Q), being found to be activated and transforming. P29S, N92I, and C157Y mutants of RAC1 were shown to exist preferentially in the GTP-bound state as a result of a rapid transition from the GDP-bound state, rather than as a result of a reduced intrinsic GTPase activity. Activating mutations of RAC GTPases were thus found in a wide variety of human cancers at a low frequency; however, given their marked transforming ability, the mutant proteins are potential targets for the development of new therapeutic agents.

A prospective PCR-based screening for the EML4-ALK oncogene in non-small cell lung cancer.

PURPOSE: EML4-ALK is a lung cancer oncogene, and ALK inhibitors show marked therapeutic efficacy for tumors harboring this fusion gene. It remains unsettled, however, how the fusion gene should be detected in specimens other than formalin-fixed, paraffin-embedded tissue. We here tested whether reverse transcription PCR (RT-PCR)-based detection of EML4-ALK is a sensitive and reliable approach. EXPERIMENTAL DESIGN: We developed a multiplex RT-PCR system to capture ALK fusion transcripts and applied this technique to our prospective, nationwide cohort of non-small cell lung cancer (NSCLC) in Japan. RESULTS: During February to December 2009, we collected 916 specimens from 853 patients, quality filtering of which yielded 808 specimens of primary NSCLC from 754 individuals. Screening for EML4-ALK and KIF5B-ALK with our RT-PCR system identified EML4-ALK transcripts in 36 samples (4.46%) from 32 individuals (4.24%). The RT-PCR products were detected in specimens including bronchial washing fluid (n = 11), tumor biopsy (n = 8), resected tumor (n = 7), pleural effusion (n = 5), sputum (n = 4), and metastatic lymph node (n = 1). The results of RT-PCR were concordant with those of sensitive immunohistochemistry with ALK antibodies. CONCLUSIONS: Multiplex RT-PCR was confirmed to be a reliable technique for detection of ALK fusion transcripts. We propose that diagnostic tools for EML4-ALK should be selected in a manner dependent on the available specimen types. FISH and sensitive immunohistochemistry should be applied to formalin-fixed, paraffin-embedded tissue, but multiplex RT-PCR is appropriate for other specimen types.

Oncogenic MAP2K1 mutations in human epithelial tumors.

The scirrhous subtype of gastric cancer is a highly infiltrative tumor with a poor outcome. To identify a transforming gene in this intractable disorder, we constructed a retroviral complementary DNA (cDNA) expression library from a cell line (OCUM-1) of scirrhous gastric cancer. A focus formation assay with the library and mouse 3T3 fibroblasts led to the discovery of a transforming cDNA, encoding for MAP2K1 with a glutamine-to-proline substitution at amino acid position 56. Interestingly, treatment with a MAP2K1-specific inhibitor clearly induced cell death of OCUM-1 but not of other two cells lines of scirrhous gastric cancer that do not carry MAP2K1 mutations, revealing the essential role of MAP2K1(Q56P) in the transformation mechanism of OCUM-1 cells. By using a next-generation sequencer, we further conducted deep sequencing of the MAP2K1 cDNA among 171 human cancer specimens or cell lines, resulting in the identification of one known (D67N) and four novel (R47Q, R49L, I204T and P306H) mutations within MAP2K1. The latter four changes were further shown to confer transforming potential to MAP2K1. In our experiments, a total of six (3.5%) activating mutations in MAP2K1 were thus identified among 172 of specimens or cell lines for human epithelial tumors. Given the addiction of cancer cells to the elevated MAP2K1 activity for proliferation, human cancers with such MAP2K1 mutations are suitable targets for the treatment with MAP2K1 inhibitors.

High-throughput resequencing of target-captured cDNA in cancer cells.

The recent advent of whole exon (exome)-capture technology, coupled with second-generation sequencers, has made it possible to readily detect genomic alterations that affect encoded proteins in cancer cells. Such target resequencing of the cancer genome, however, fails to detect most clinically-relevant gene fusions, given that such oncogenic fusion genes are often generated through intron-to-intron ligation. To develop a resequencing platform that simultaneously captures point mutations, insertions-deletions (indels), and gene fusions in the cancer genome, we chose cDNA as the input for target capture and extensive resequencing, and we describe the versatility of such a cDNA-capture system. As a test case, we constructed a custom target-capture system for 913 cancer-related genes, and we purified cDNA fragments for the target gene set from five cell lines of CML. Our target gene set included Abelson murine leukemia viral oncogene homolog 1 (ABL1), but it did not include breakpoint cluster region (BCR); however, the sequence output faithfully detected reads spanning the fusion points of these two genes in all cell lines, confirming the ability of cDNA capture to detect gene fusions. Furthermore, computational analysis of the sequence dataset successfully identified non-synonymous mutations and indels, including those of tumor protein p53 (TP53). Our data might thus support the feasibility of a cDNA-capture system coupled with massively parallel sequencing as a simple platform for the detection of a variety of anomalies in protein-coding genes among hundreds of cancer specimens.

MCPIP1 ribonuclease antagonizes dicer and terminates microRNA biogenesis through precursor microRNA degradation.

MicroRNAs (miRNAs) are versatile regulators of gene expression and undergo complex maturation processes. However, the mechanism(s) stabilizing or reducing these small RNAs remains poorly understood. Here we identify mammalian immune regulator MCPIP1 (Zc3h12a) ribonuclease as a broad suppressor of miRNA activity and biogenesis, which counteracts Dicer, a central ribonuclease in miRNA processing. MCPIP1 suppresses miRNA biosynthesis via cleavage of the terminal loops of precursor miRNAs (pre-miRNAs). MCPIP1 also carries a vertebrate-specific oligomerization domain important for pre-miRNA recognition, indicating its recent evolution. Furthermore, we observed potential antagonism between MCPIP1 and Dicer function in human cancer and found a regulatory role of MCPIP1 in the signaling axis comprising miR-155 and its target c-Maf. These results collectively suggest that the balance between processing and destroying ribonucleases modulates miRNA biogenesis and potentially affects pathological miRNA dysregulation. The presence of this abortive processing machinery and diversity of MCPIP1-related genes may imply a dynamic evolutional transition of the RNA silencing system.

Overexpression of Enhancer of zeste homolog 2 with trimethylation of lysine 27 on histone H3 in adult T-cell leukemia/lymphoma as a target for epigenetic therapy.

BACKGROUND: Enhancer of zeste homolog 2 is a component of the Polycomb repressive complex 2 that mediates chromatin-based gene silencing through trimethylation of lysine 27 on histone H3. This complex plays vital roles in the regulation of development-specific gene expression. DESIGN AND METHODS: In this study, a comparative microarray analysis of gene expression in primary adult T-cell leukemia/lymphoma samples was performed, and the results were evaluated for their oncogenic and clinical significance. RESULTS: Significantly higher levels of Enhancer of zeste homolog 2 and RING1 and YY1 binding protein transcripts with enhanced levels of trimethylation of lysine 27 on histone H3 were found in adult T-cell leukemia/lymphoma cells compared with those in normal CD4(+) T cells. Furthermore, there was an inverse correlation between the expression level of Enhancer of zeste homolog 2 and that of miR-101 or miR-128a, suggesting that the altered expression of the latter miRNAs accounts for the overexpression of the former. Patients with high Enhancer of zeste homolog 2 or RING1 and YY1 binding protein transcripts had a significantly worse prognosis than those without it, indicating a possible role of these genes in the oncogenesis and progression of this disease. Indeed, adult T-cell leukemia/lymphoma cells were sensitive to a histone methylation inhibitor, 3-deazaneplanocin A. Furthermore, 3-deazaneplanocin A and histone deacetylase inhibitor panobinostat showed a synergistic effect in killing the cells. CONCLUSIONS: These findings reveal that adult T-cell leukemia/lymphoma cells have deregulated Polycomb repressive complex 2 with over-expressed Enhancer of zeste homolog 2, and that there is the possibility of a new therapeutic strategy targeting histone methylation in this disease.

Differential effect of genetic variants of Na(+)-taurocholate co-transporting polypeptide (NTCP) and organic anion-transporting polypeptide 1B1 (OATP1B1) on the uptake of HMG-CoA reductase inhibitors.

The purpose of this study was to investigate the effect of genetic variations in organic anion-transporting polypeptide 1B1 (OATP1B1) and Na(+)/taurocholate co-transporting polypeptide (NTCP) on the uptake of various statins having different affinities for these transporters. The functional activities and simultaneous expression of NTCP and OATP1B1 were confirmed by the uptake of taurocholate and estrone-3-sulphate as representative substrates for NTCP and OATP1B1, respectively, and by an immunofluorescence analysis. The substrate specificities of NTCP and OATP1B1 for statins and the effects of genetic variations on the uptake of rosuvastatin, pitavastatin, and atorvastatin were measured. Based on the K(m) values and intrinsic clearances of the three statins, pitavastatin was taken up more efficiently than rosuvastatin and atorvastatin by OATP1B1. Consequently, the cellular accumulation of pitavastatin was modulated according to the genetic variation of OATP1B1 (OATP1B1*15), rather than NTCP*2. In contrast, NTCP*2 displayed greater transport of atorvastatin and rosuvastatin, compared with NTCP wild type. Thus, the measurements of decreased rosuvastatin and atorvastatin transport by OATP1B1*15 were confounded by the presence of NTCP and its genetic variant, NTCP*2. In conclusion, the functional consequences of genetic variants of NTCP and OATP1B1 may be different for various statins, depending on the substrate specificity of the OATP1B1 and NTCP transporters.

EML4-ALK mutations in lung cancer that confer resistance to ALK inhibitors.

The EML4 (echinoderm microtubule-associated protein-like 4)-ALK (anaplastic lymphoma kinase) fusion-type tyrosine kinase is an oncoprotein found in 4 to 5% of non-small-cell lung cancers, and clinical trials of specific inhibitors of ALK for the treatment of such tumors are currently under way. Here, we report the discovery of two secondary mutations within the kinase domain of EML4-ALK in tumor cells isolated from a patient during the relapse phase of treatment with an ALK inhibitor. Each mutation developed independently in subclones of the tumor and conferred marked resistance to two different ALK inhibitors. (Funded by the Ministry of Health, Labor, and Welfare of Japan, and others.).

Incidentally proven pulmonary "ALKoma".

Genetic alterations of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) inversion were recently found in lung cancer. A 39-year-old woman with multiple brain metastases and bulky mediastinal lymph node metastases was admitted. Biopsy from her supraclavicular lymph nodes was performed to differentiate the diagnosis between lymphoma and lung cancer. Pathologically, the lymph nodes had a feature of adenocarcinoma. On the other hand, the commercially available chromosomal fluorescent in situ hybridization (FISH) analysis showed split signals of ALK, which was confirmed to be the EML4-ALK inversion. The commercial-based ALK FISH is useful for screening pulmonary ALKoma.

Identification of the transforming activity of Indian hedgehog by retroviral expression screening.

To identify novel cancer-promoting genes in biliary tract cancer (BTC), we constructed a retroviral cDNA expression library from a clinical specimen of BTC with anomalous pancreaticobiliary duct junction (APBDJ), and used the library for a focus formation assay with 3T3 fibroblasts. One of the cDNAs rescued from transformed foci was found to encode Indian hedgehog homolog (IHH). The oncogenic potential of IHH was confirmed both in vitro with the focus formation assay and in vivo with a tumorigenicity assay in nude mice. The isolated IHH cDNA had no sequence alterations, suggesting that upregulation of IHH expression may contribute to malignant transformation. Quantitation of IHH mRNA among clinical specimens has revealed that the expression level of IHH in BTC with APBDJ is higher than that in BTC without APBDJ and than in non-cancerous biliary tissues. Our data thus implicate a direct role of IHH in the carcinogenesis of BTC with APBDJ.

Identification of transforming activity of free fatty acid receptor 2 by retroviral expression screening.

Gallbladder cancer (GBC) is a highly fatal malignancy in humans. Genetic alterations in KRAS or TP53 as well as overexpression of ERBB2 have been shown to contribute to the development of certain types of GBC. However, many cases of GBC do not harbor such genetic changes, with other transforming events awaiting discovery. We here tried to identify novel cancer-promoting genes in GBC, with the use of a retroviral cDNA expression library. A retroviral cDNA expression library was constructed from a surgically resected clinical specimen of GBC, and was used to infect 3T3 fibroblasts in a focus formation assay. cDNA incorporated into the transformed foci was rescued by PCR. One such cDNA was found to encode free fatty acid receptor 2 (FFAR2), a G protein-coupled receptor for short-chain fatty acids. The oncogenic potential of FFAR2 was confirmed both in vitro with the focus formation assay and by evaluation of cell growth in soft agar as well as in vivo with a tumorigenicity assay in nude mice. The isolated FFAR2 cDNA had no sequence alterations, suggesting that upregulation of FFAR2 expression may contribute to malignant transformation. Indeed, all of quantitative RT-PCR, in situ hybridization, and immunohistochemical analyses showed that the amount of FFAR2 mRNA and its protein product was increased in digestive tract cancer specimens. Furthermore, short-chain fatty acids potentiated the mitogenic action of FFAR2 in 3T3 cells. Our data thus, for the first time, implicate FFAR2 in carcinogenesis of the digestive tract.

Screening for genetic abnormalities involved in ovarian carcinogenesis using retroviral expression libraries.

The purpose of this study was to screen for genes involved in ovarian carcinogenesis in an attempt to develop an effective molecular-targeted therapy for ovarian cancer. We constructed retroviral expression libraries for the human ovarian cancer cell lines SHIN-3 and TYK-CPr, and performed a focus formation assay with 3T3 cells. As a result, proteasome subunit beta-type 2 (PSMB2), ubiquitin-specific protease 14 (USP14), and keratin 8 (KRT8) were identified from SHIN-3, and polymerase II RNA subunit (POLR2E), chaperonin containing T-complex polypeptide 1 subunit 4 (CCT4), glia maturation factor beta (GMFB), and neuroblastoma ras viral oncogene homolog (NRAS) from TYK-CPr. NRAS gene analysis revealed a CAA --> AAA substitution at codon 61, resulting in a Glu --> Lys change at position 61. When the mutant NRAS was introduced into fibroblasts for its expression, many transformed foci were generated, confirming the transforming ability of the mutant NRAS.

Potential role of miR-29b in modulation of Dnmt3a and Dnmt3b expression in primordial germ cells of female mouse embryos.

MicroRNAs (miRNAs) are a recently discovered class of small noncoding RNAs and are implicated in an increasing number of biological processes. To examine whether miRNAs might contribute to sexual differentiation, we performed expression profiling of miRNAs in mouse embryonic gonads with the use of a highly sensitive cloning method, mRAP. Our profiling data revealed substantial differences in the miRNA repertoire between male and female gonads at embryonic (E) day 13.5 (E13.5), suggesting that such differentially expressed miRNAs may function in sexual differentiation. Female-specific miRNAs included miR-29b, which also has been known to be expressed in a similar sex-dependent manner in the gonads of chicken embryos, suggestive of a conserved role in gonadogenesis. Transcripts of the human genes for the de novo methyltransferases DNMT3A and DNMT3B have been identified as targets of miR-29b, and we found that mouse miR-29b also negatively regulates Dnmt3a and Dnmt3b expression in luciferase reporter assays. We also found that miR-29b is expressed in mouse primordial germ cells (PGCs) at E13.5 and that its expression is up-regulated in a female-specific manner between E13.5 and E17.5, when male-specific de novo methylation of the PGC genome is known to occur. Our data thus suggest that miR-29b may play an important role in female gonadal development by targeting Dnmt3a and Dnmt3b and thereby modulating methylation of genomic DNA in PGCs.

KIF5B-ALK, a novel fusion oncokinase identified by an immunohistochemistry-based diagnostic system for ALK-positive lung cancer.

PURPOSE: 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. EXPERIMENTAL DESIGN: 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. RESULTS: 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. CONCLUSIONS: 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.

EML4-ALK lung cancers are characterized by rare other mutations, a TTF-1 cell lineage, an acinar histology, and young onset.

A subset of lung cancers harbors a small inversion within chromosome 2p, giving rise to a transforming fusion gene, EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene), which encodes an activated tyrosine kinase. We have earlier examined the presence of EML4-ALK by multiplex reverse transcription-polymerase chain reaction in 363 specimens of lung cancer, identifying 11 adenocarcinoma cases featuring the fusion gene. In this study, we clinicopathologically examined the characteristics of the EML4-ALK-positive cases, including the mutation status of EGFR, KRAS, and TP53, and whether they were of thyroid transcription factor-1 (TTF-1) cell lineage or not. Of 11 patients, 4 (36%) with EML4-ALK-positive lung adenocarcinomas who were below 50 years of age were affected by these diseases, as compared with 12 of 242 patients (5.0%) with EML4-ALK-negative lung adenocarcinomas (P=0.00038). EML4-ALK-positive lung adenocarcinomas were characterized by less-differentiated grade (P=0.0082) and acinar-predominant structure (P<0.0001) in histology. Furthermore, the presence of EML4-ALK appears to be mutually exclusive for EGFR and KRAS mutations (P=0.00018), whereas coexisting with TP53 mutations at a low frequency (1/11=9.1%), and correlating with non- or light smoking (P=0.040), in line with the TTF-1 immunoreactivity. Thus, EML4-ALK-positive tumors may form a distinct entity among lung adenocarcinomas, characterized by young onset, acinar histology, no or rare mutations in EGFR, KRAS, and TP53, and a TTF-1 cell lineage, all in agreement with the prevalence in non- or light smokers.

Genome-wide histone methylation profile for heart failure.

Epigenetic alterations are implicated in the development of cardiac hypertrophy and heart failure, but little is known of which epigenetic changes in which regions of the genome play such a role. We now show that trimethylation of histone H3 on lysine-4 (K4TM) or lysine-9 (K9TM) is markedly affected in cardiomyocytes in association with the development of heart failure in a rat disease model. High-throughput pyrosequencing performed with ChIP products for K4TM or K9TM prepared from human left ventricular tissue with retained or damaged function also revealed that protein-coding genes located in the vicinity of K4TM marks differ between functional and disabled myocytes, yet both sets of genes encode proteins that function in the same signal transduction pathways for cardiac function, indicative of differential K4TM marking during the development of heart failure. However, K9TM mark-profile was less dependent on the disease status compared to that of K4TM. Our data collectively reveal global epigenetic changes in cardiac myocytes associated with heart failure.

A mouse model for EML4-ALK-positive lung cancer.

EML4-ALK is a fusion-type protein tyrosine kinase that is generated in human non-small-cell lung cancer (NSCLC) as a result of a recurrent chromosome inversion, inv (2)(p21p23). Although mouse 3T3 fibroblasts expressing human EML4-ALK form transformed foci in culture and s.c. tumors in nude mice, it has remained unclear whether this fusion protein plays an essential role in the carcinogenesis of NSCLC. To address this issue, we have now established transgenic mouse lines that express EML4-ALK specifically in lung alveolar epithelial cells. All of the transgenic mice examined developed hundreds of adenocarcinoma nodules in both lungs within a few weeks after birth, confirming the potent oncogenic activity of the fusion kinase. Although such tumors underwent progressive enlargement in control animals, oral administration of a small-molecule inhibitor of the kinase activity of ALK resulted in their rapid disappearance. Similarly, whereas i.v. injection of 3T3 cells expressing EML4-ALK induced lethal respiratory failure in recipient nude mice, administration of the ALK inhibitor effectively cleared the tumor burden and improved the survival of such animals. These data together reinforce the pivotal role of EML4-ALK in the pathogenesis of NSCLC in humans, and they provide experimental support for the treatment of this intractable cancer with ALK inhibitors.

Oncogenic mutations of ALK kinase in neuroblastoma.

Neuroblastoma in advanced stages is one of the most intractable paediatric cancers, even with recent therapeutic advances. Neuroblastoma harbours a variety of genetic changes, including a high frequency of MYCN amplification, loss of heterozygosity at 1p36 and 11q, and gain of genetic material from 17q, all of which have been implicated in the pathogenesis of neuroblastoma. However, the scarcity of reliable molecular targets has hampered the development of effective therapeutic agents targeting neuroblastoma. Here we show that the anaplastic lymphoma kinase (ALK), originally identified as a fusion kinase in a subtype of non-Hodgkin's lymphoma (NPM-ALK) and more recently in adenocarcinoma of lung (EML4-ALK), is also a frequent target of genetic alteration in advanced neuroblastoma. According to our genome-wide scans of genetic lesions in 215 primary neuroblastoma samples using high-density single-nucleotide polymorphism genotyping microarrays, the ALK locus, centromeric to the MYCN locus, was identified as a recurrent target of copy number gain and gene amplification. Furthermore, DNA sequencing of ALK revealed eight novel missense mutations in 13 out of 215 (6.1%) fresh tumours and 8 out of 24 (33%) neuroblastoma-derived cell lines. All but one mutation in the primary samples (12 out of 13) were found in stages 3-4 of the disease and were harboured in the kinase domain. The mutated kinases were autophosphorylated and displayed increased kinase activity compared with the wild-type kinase. They were able to transform NIH3T3 fibroblasts as shown by their colony formation ability in soft agar and their capacity to form tumours in nude mice. Furthermore, we demonstrate that downregulation of ALK through RNA interference suppresses proliferation of neuroblastoma cells harbouring mutated ALK. We anticipate that our findings will provide new insights into the pathogenesis of advanced neuroblastoma and that ALK-specific kinase inhibitors might improve its clinical outcome.

Multiplex reverse transcription-PCR screening for EML4-ALK fusion transcripts.

PURPOSE: EML4-ALK is a fusion-type protein tyrosine kinase that is generated by inv(2)(p21p23) in the genome of non-small cell lung cancer (NSCLC). To allow sensitive detection of EML4-ALK fusion transcripts, we have now developed a multiplex reverse transcription-PCR (RT-PCR) system that captures all in-frame fusions between the two genes. EXPERIMENTAL DESIGN: Primers were designed to detect all possible in-frame fusions of EML4 to exon 20 of ALK, and a single-tube multiplex RT-PCR assay was done with total RNA from 656 solid tumors of the lung (n = 364) and 10 other organs. RESULTS: From consecutive lung adenocarcinoma cases (n = 253), we identified 11 specimens (4.35%) positive for fusion transcripts, 9 of which were positive for the previously identified variants 1, 2, and 3. The remaining two specimens harbored novel transcript isoforms in which exon 14 (variant 4) or exon 2 (variant 5) of EML4 was connected to exon 20 of ALK. No fusion transcripts were detected for other types of lung cancer (n = 111) or for tumors from 10 other organs (n = 292). Genomic rearrangements responsible for the fusion events in NSCLC cells were confirmed by genomic PCR analysis and fluorescence in situ hybridization. The novel isoforms of EML4-ALK manifested marked oncogenic activity, and they yielded a pattern of cytoplasmic staining with fine granular foci in immunohistochemical analysis of NSCLC specimens. CONCLUSIONS: These data reinforce the importance of accurate diagnosis of EML4-ALK-positive tumors for the optimization of treatment strategies.