Compound EGFR mutations, defined as double or multiple mutations in the EGFR tyrosine kinase domain, are frequently detected with advances in sequencing technology but its clinical significance is unclear. This study analyzed 61 cases of EGFR mutation positive lung adenocarcinoma using next-generation sequencing (NGS) based repeated deep sequencing panel of 16 genes that contain actionable mutations and investigated clinical implication of compound EGFR mutations. Compound EGFR mutation was detected in 15 (24.6%) of 61 cases of EGFR mutation-positive lung adenocarcinoma. The majority (12/15) of compound mutations are combination of the atypical mutation and typical mutations such as exon19 deletion, L858R or G719X substitutions, or exon 20 insertion whereas 3 were combinations of rare atypical mutations. The patients with compound mutation showed shorter overall survival than those with simple mutations (83.7 vs. 72.8 mo; P = 0.020, Breslow test). Among the 115 missense mutations discovered in the tested genes, a few number of actionable mutations were detected irrelevant to the subtype of EGFR mutations, including ALK rearrangement, BCL2L11 intron 2 deletion, KRAS c.35G>A, PIK3CA c.1633G>A which are possible target of crizotinib, BH3 mimetics, MEK inhibitors, and PI3K-tyrosine kinase inhibitors, respectively. 31 missense mutations were detected in the cases with simple mutations whereas 84 in those with compound mutation, showing that the cases with compound missense mutation have higher burden of missense mutations (P = 0.001, independent sample t-test). Compound EGFR mutations are detected at a high frequency using NGS-based repeated deep sequencing. Because patients with compound EGFR mutations showed poor clinical outcomes, they should be closely monitored during follow-up.

BackgroundBiopsy for lung cancer diagnosis is usually done at a single site. But it is unclear that genetic information at one biopsy site represents that of other lesions and is sufficient for therapeutic decision making.MethodsNon-synonymous mutations and insertions/deletions of 16 genes containing actionable mutations, and intron 2 deletion polymorphism of Bcl2-like11 were analyzed in 41 primary tumor and metastatic lymph node (L/N) matched, pStage IIA ~ IIIA non-small cell lung cancer (NSCLC) samples using a next generation sequencing based technique.ResultsA total of 249 mutations, including 213 non-synonymous mutations, 32 deletions, and four insertions were discovered. There was a higher chance of discovering non-synonymous mutations in the primary tumors than in the metastatic L/N (138 (64.8%) vs. 75 (35.2%)). In the primary tumors, 106 G > A:C > T transitions (76.8%) of 138 non-synonymous mutations were detected, whereas in the metastatic L/N, 44 (58.7%) of 75 were discovered. A total 24 (11.3%) out of 213 non-synonymous mutations were developed in the context of APOBEC signature. Of those, 21 (87.5%) was detected in the primary tumors and 4 (16.7%) was detected in the metastatic L/N. When the mutation profiles between primary tumor and metastatic L/N were compared, 13 (31.7%) of 41 cases showed discrepant mutation profile. There were no statistically significant differences in disease free survival and overall survival between groups showing identical mutation profiles and those with discrepancy between primary and metastatic L/N.ConclusionsGenetic heterogeneity between the primary and L/N metastatic lesions is not infrequent finding to consider when interpreting genomic data based on the result of one site inspection. A large prospective study may be needed to evaluate the impact of genetic heterogeneity on the clinical outcomes of NSCLC patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2049-z) contains supplementary material, which is available to authorized users.

Asthma is a complex inflammatory disease and its prevalence has increased worldwide, especially in young children. In this study, we used a '24-hour recall method' to identify differences between children with and without asthma in energy intake and energy-adjusted nutrition intake. We also performed reverse transcription-polymerase chain reaction (RT-PCR) with pathway-targeted arrays (RT2 Profiler TM PCR Array) to investigate the expression profiles of chemokines and cytokines in children with asthma. The intake of vitamin C in mild and moderate asthma was significantly higher than that in healthy controls. Vitamin E intake in the mild asthma group was also significantly higher. Twenty-three genes were expressed at higher levels in severe asthma compared with healthy controls. Using the human Th1-Th2-Th3 PCR Array, we found 17 genes were upregulated in severe asthma, including the Th2-related genes CCL7, IL13, and CCL-11 (eotaxin). These PCR Array results revealed that the genes that were most profoundly increased in asthma encoded for key proinflammatory and chemotactic molecules. Our observations lead us to speculate that the interaction between gene expression and dietary intake is important for the development of asthma.

Human genomic short tandem repeats (STRs) are specific gene sequences containing base pairs that are repeatedly arranged. From the various methods available for identifying individuals, STR analysis is the method most widely used in forensic science. Conventional polymerase chain reaction (PCR) was used for STR typing, and the PCR products, consisting of amplified STR loci (amplicons) were electrophoresed with a DNA analysis device. About ten STR markers were used as standards for STR characterization and analysis of size. Extensive efforts are currently being made to explore the STR sequence diversity by analyzing multiple chromosomal loci using next generation sequencing (NGS). NGS greatly facilitates STR marker analysis for individual identification and the complete sequencing of any given sample through concurrent high-throughput sequencing of multiple loci. As a result, NGS data are more accurate and comprehensive compared to that in a conventional database. In order to overcome the limitations of the currently used size-based STR analysis method, we have typed the DNA of 13 combined DNA index system (CODIS) STR markers using Ion PGM. This kit, developed by Ion Torrent, enables the analysis of STR alleles and the sequencing of corresponding genes. We then analyzed the alleles using the HID_STR_Genotyper plugin. Through this, we determined the sequence of the allele type 15 at the D3S1358 locus in all NIST SRM 2391b samples. This allowed for the verification of the exact type of allele, which the conventional size-based STR typing methods could not resolve.

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