Primary Immunodeficiencies (PID) are genetically inherited disorders characterized by defects of the immune system, leading to increased susceptibility to infection. Due to the variety of clinical ...symptoms and the complexity of current diagnostic procedures, accurate diagnosis of PID is often difficult in daily clinical practice. Thanks to the advent of "next generation" sequencing technologies and target enrichment methods, the development of multiplex diagnostic assays is now possible. In this study, we applied a selector-based target enrichment assay to detect disease-causing mutations in 179 known PID genes. The usefulness of this assay for molecular diagnosis of PID was investigated by sequencing DNA from 33 patients, 18 of which had at least one known causal mutation at the onset of the experiment. We were able to identify the disease causing mutations in 60% of the investigated patients, indicating that the majority of PID cases could be resolved using a targeted sequencing approach. Causal mutations identified in the unknown patient samples were located in STAT3, IGLL1, RNF168 and PGM3. Based on our results, we propose a stepwise approach for PID diagnostics, involving targeted resequencing, followed by whole transcriptome and/or whole genome sequencing if causative variants are not found in the targeted exons.
•NTRK fusions are extremely rare in non-small cell lung cancer.•High NTRK RNA and protein expression is present in a subgroup of NTRK fusion negative lung cancer cases.•A positive immunohistochemical ...assay should be confirmed by an independent molecular analysis.
The small molecule inhibitors larotrectinib and entrectinib have recently been approved as cancer agnostic drugs in patients with tumours harbouring a rearrangement of the neurotrophic tropomyosin receptor kinase (NTRK). These oncogenic fusions are estimated to occur in 0.1–3 % of non-small cell lung cancers (NSCLC). Although molecular techniques are most reliable for fusion detection, immunohistochemical analysis is considered valuable for screening. Therefore, we evaluated the newly introduced diagnostic immunohistochemical assay (clone EPR17341) on a representative NSCLC cohort.
Cancer tissue from 688 clinically and molecularly extensively annotated NSCLC patients were comprised on tissue microarrays and stained with the pan-TRK antibody clone EPR17341. Positive cases were further analysed with the TruSight Tumor 170 RNA assay (Illumina). Selected cases were also tested with a NanoString NTRK fusion assay. For 199 cases, NTRK RNA expression data were available from previous RNA sequencing analysis.
Altogether, staining patterns for 617 NSCLC cases were evaluable. Of these, four cases (0.6 %) demonstrated a strong diffuse cytoplasmic and membranous staining, and seven cases a moderate staining (1.1 %). NanoString or TST170-analysis could not confirm an NTRK fusion in any of the IHC positive cases, or any of the cases with high mRNA levels. In the four cases with strong staining intensity in the tissue microarray, whole section staining revealed marked heterogeneity of NTRK protein expression.
The presence of NTRK fusion genes in non-small cell lung cancer is exceedingly rare. The use of the immunohistochemical NTRK assay will result in a small number of false positive cases. This should be considered when the assay is applied as a screening tool in clinical diagnostics.
•No technical bias between fresh frozen and FFPE samples.•A high fraction of adenocarcinoma patients with activating KRAS mutations.•Mutations in TP53, STK11 and SMARCA4 linked to poor prognosis in ...adenocarcinoma.•Mutations in CSMD3 linked to better prognosis in squamous cell carcinoma.•Co-mutations in TP53 or STK11 confer poor prognosis in KRAS positive patients.
Non-small cell lung cancer (NSCLC) is a heterogeneous disease with unique combinations of somatic molecular alterations in individual patients, as well as significant differences in populations across the world with regard to mutation spectra and mutation frequencies. Here we aim to describe mutational patterns and linked clinical parameters in a population-based NSCLC cohort.
Using targeted resequencing the mutational status of 82 genes was evaluated in a consecutive Swedish surgical NSCLC cohort, consisting of 352 patient samples from either fresh frozen or formalin fixed paraffin embedded (FFPE) tissues. The panel covers all exons of the 82 genes and utilizes reduced target fragment length and two-strand capture making it compatible with degraded FFPE samples.
We obtained a uniform sequencing coverage and mutation load across the fresh frozen and FFPE samples by adaption of sequencing depth and bioinformatic pipeline, thereby avoiding a technical bias between these two sample types. At large, the mutation frequencies resembled the frequencies seen in other western populations, except for a high frequency of KRAS hotspot mutations (43%) in adenocarcinoma patients. Worse overall survival was observed for adenocarcinoma patients with a mutation in either TP53, STK11 or SMARCA4. In the adenocarcinoma KRAS-mutated group poor survival appeared to be linked to concomitant TP53 or STK11 mutations, and not to KRAS mutation as a single aberration. Similar results were seen in the analysis of publicly available data from the cBioPortal. In squamous cell carcinoma a worse prognosis could be observed for patients with MLL2 mutations, while CSMD3 mutations were linked to a better prognosis.
Here we have evaluated the mutational status of a NSCLC cohort. We could not confirm any survival impact of isolated driver mutations. Instead, concurrent mutations in TP53 and STK11 were shown to confer poor survival in the KRAS-positive adenocarcinoma subgroup.
Background : Patients with non-small cell lung cancer (NSCLC) harboring a ROS proto-oncogene 1 (ROS1)-rearrangement respond to treatment with ROS1 inhibitors. To distinguish these rare cases, ...screening with immunohistochemistry (IHC) for ROS1 protein expression has been suggested. However, the reliability of such an assay and the comparability of the antibody clones has been debated. Therefore we evaluated the diagnostic performance of current detection strategies for ROS1-rearrangement in two NSCLC-patient cohorts.
Methods : Resected tissue samples, retrospectively collected from consecutive NSCLC-patients surgically treated at Uppsala University Hospital were incorporated into tissue microarrays all n=676, adenocarcinomas (AC) n=40 1, squamous cell carcinomas (SCC) n=2 13, other NSCLC n=62. ROS1rearrangements were detected using fluorescence in situ hybridization (FISH) (Abbott Molecular; ZytoVision). In parallel, ROS1 protein expression was detected using IHC with three antibody clones (D4D6, SP384, EPMGHR2) and accuracy, sensitivity, and specificity were determined. Gene expression microarray data (Affymetrix) and RNA-sequencing data were available for a subset of patients. NanoString analyses were performed for samples with positive or ambiguous results (n=21).
Results : Using FISH, 2/630 (0.3% all NSCLC; 0.5% non-squamous NSCLC) cases were positive for ROS1 fusion. Additionally, nine cases demonstrated ambiguous FISH results. Using IHC, ROS1 protein expression was detected in 24/665 (3.6% all NSCLC; 5.1% non-squamous NSCLC) cases with clone D4D6, in 18/639 (2.8% all NSCLC; 3.9% non-squamous NSCLC) cases with clone SP384, and in 1/593 (0.2% all NSCLC; 0.3% non-squamous NSCLC) case with clone EPMGHR2. Elevated RNA-levels were seen in 19/369 (5.1%) cases (Affymetrix and RNA-sequencing combined). The overlap of positive results between the assays was poor. Only one of the FISH-positive cases was positive with all antibodies and demonstrated high RNA-expression. This rearrangement was confirmed in the NanoString-assay and also in the RNA sequencing data. Other cases with high protein/RNA-expression or ambiguous FISH were negative in the NanoString-assay.
Conclusions : The occurrence of ROS1 fusions is low in our cohorts. The IHC assays detected the fusions, but the accuracy varied depending on the clone. The presumably false-positive and uncertain FISH results questions this method for detection of ROS1-rearrangements. Thus, when IHC is used for screening, transcript-based assays are preferable for validation in clinical diagnostics.
In recent years, the advent of massively parallel next-generation sequencing technologies has enabled substantial advances in the study of human diseases. Combined with targeted DNA enrichment ...methods, high sequence coverage can be obtained for different genes simultaneously at a reduced cost per sample, creating unique opportunities for clinical cancer diagnostics. However, the formalin-fixed, paraffin-embedded (FFPE) process of tissue samples, routinely used in pathology departments, results in DNA fragmentation and nucleotide modifications that introduce a number of technical challenges for downstream biomolecular analyses. We evaluated the HaloPlex target enrichment system for somatic mutation detection in 80 tissue fractions derived from 20 clinical cancer cases with paired tumor and normal tissue available in both FFPE and fresh-frozen format. Several modifications to the standard method were introduced, including a reduced target fragment length and two strand capturing. We found that FFPE material can be used for HaloPlex-based target enrichment and next-generation sequencing, even when starting from small amounts of DNA. By specifically capturing both strands for each target fragment, we were able to reduce the number of false-positive errors caused by FFPE-induced artifacts and lower the detection limit for somatic mutations. We believe that the HaloPlex method presented here will be broadly applicable as a tool for somatic mutation detection in clinical cancer settings.
Heterogeneity and low incidence comprise the biggest challenge in sarcoma diagnosis and treatment. Chemotherapy, although efficient for some sarcoma subtypes, generally results in poor clinical ...responses and is mostly recommended for advanced disease. Specific genomic aberrations have been identified in some sarcoma subtypes but few of them can be targeted with approved drugs.
We cultured and characterised patient-derived sarcoma cells and evaluated their sensitivity to 525 anti-cancer agents including both approved and non-approved drugs. In total, 14 sarcomas and 5 healthy mesenchymal primary cell cultures were studied. The sarcoma biopsies and derived cells were characterised by gene panel sequencing, cancer driver gene expression and by detecting specific fusion oncoproteins in situ in sarcomas with translocations.
Soft tissue sarcoma cultures were established from patient biopsies with a success rate of 58%. The genomic profile and drug sensitivity testing on these samples helped to identify targeted inhibitors active on sarcomas. The cSrc inhibitor Dasatinib was identified as an active drug in sarcomas carrying chromosomal translocations. The drug sensitivity of the patient sarcoma cells ex vivo correlated with the response to the former treatment of the patient.
Our results show that patient-derived sarcoma cells cultured in vitro are relevant and practical models for genotypic and phenotypic screens aiming to identify efficient drugs to treat sarcoma patients with poor treatment options.
In recent years, DISC1 has emerged as one of the most credible and best supported candidate genes for schizophrenia and related neuropsychiatric disorders. Furthermore, increasing evidence--both ...genetic and functional--indicates that many of its protein interaction partners are also involved in the development of these diseases. In this study, we applied a pooled sample 454 sequencing strategy, to explore the contribution of genetic variation in DISC1 and 10 of its interaction partners (ATF5, Grb2, FEZ1, LIS-1, PDE4B, NDE1, NDEL1, TRAF3IP1, YWHAE, and ZNF365) to schizophrenia susceptibility in an isolated northern Swedish population. Mutation burden analysis of the identified variants in a population of 486 SZ patients and 514 control individuals, revealed that non-synonymous rare variants with a MAF<0.01 were significantly more present in patients compared to controls (8.64% versus 4.7%, P = 0.018), providing further evidence for the involvement of DISC1 and some of its interaction partners in psychiatric disorders. This increased burden of rare missense variants was even more striking in a subgroup of early onset patients (12.9% versus 4.7%, P = 0.0004), highlighting the importance of studying subgroups of patients and identifying endophenotypes. Upon investigation of the potential functional effects associated with the identified missense variants, we found that ∼90% of these variants reside in intrinsically disordered protein regions. The observed increase in mutation burden in patients provides further support for the role of the DISC1 pathway in schizophrenia. Furthermore, this study presents the first evidence supporting the involvement of mutations within intrinsically disordered protein regions in the pathogenesis of psychiatric disorders. As many important biological functions depend directly on the disordered state, alteration of this disorder in key pathways may represent an intriguing new disease mechanism for schizophrenia and related neuropsychiatric diseases. Further research into this unexplored domain will be required to elucidate the role of the identified variants in schizophrenia etiology.
The contribution of somatic mutations to metastasis of colorectal cancers is currently unknown. To find mutations involved in the colorectal cancer metastatic process, we performed deep mutational ...analysis of 676 genes in 107 stages II to IV primary colorectal cancer, of which half had metastasized. The mutation prevalence in the ephrin (EPH) family of tyrosine kinase receptors was 10-fold higher in primary tumors of metastatic colorectal than in nonmetastatic cases and preferentially occurred in stage III and IV tumors. Mutational analyses
confirmed expression of mutant EPH receptors. To enable functional studies of EPHB1 mutations, we demonstrated that DLD-1 colorectal cancer cells expressing EPHB1 form aggregates upon coculture with ephrin B1 expressing cells. When mutations in the fibronectin type III and kinase domains of EPHB1 were compared with wild-type EPHB1 in DLD-1 colorectal cancer cells, they decreased ephrin B1-induced compartmentalization. These observations provide a mechanistic link between EPHB receptor mutations and metastasis in colorectal cancer.
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In the present study, the existing life stage-specific cDNA library was extended with energy- and molting-related genes using Suppression Subtractive Hybridization PCR and a microarray for the ...aquatic test organism
Daphnia magna was created. A gene set of 2455 fragments was produced belonging to different pathways such as carbohydrate and lipid metabolism, O
2 transport and heme metabolism, immune response, embryo development, cuticula metabolism and visual perception pathways. Using this custom microarray, gene expression profiles were generated from neonates exposed to three concentrations of the anti-ecdysteroidal fungicide fenarimol (0.5, 0.75, 1
μg/ml) during 48
h and 96
h. In total, 59 non-redundant genes were differentially expressed, of which more genes were down- than up-regulated. The gene expression data indicated a main effect on molting specific pathways. At the highest concentration, a set of proteolytic enzymes – including different serine proteases and carboxypeptidases – were induced whereas different cuticula proteins were down-regulated (48
h). Moreover, effects on embryo development were demonstrated at the gene expression as well as at the organismal level. The embryo development related gene vitellogenin was differentially expressed after 96
h of exposure together with a significant increase in embryo abnormalities in the offspring. This study suggests that this
Daphnia magna microarray is of great further value for the elucidation of molecular mechanisms of toxicity and for the future development of specific biomarkers for hazard characterization.
We evaluated multiplex PCR amplification as a front-end for high-throughput sequencing, to widen the applicability of massive parallel sequencers for the detailed analysis of complex genomes. Using ...multiplex PCR reactions, we sequenced the complete coding regions of seven genes implicated in peripheral neuropathies in 40 individuals on a GS-FLX genome sequencer (Roche). The resulting dataset showed highly specific and uniform amplification. Comparison of the GS-FLX sequencing data with the dataset generated by Sanger sequencing confirmed the detection of all variants present and proved the sensitivity of the method for mutation detection. In addition, we showed that we could exploit the multiplexed PCR amplicons to determine individual copy number variation (CNV), increasing the spectrum of detected variations to both genetic and genomic variants. We conclude that our straightforward procedure substantially expands the applicability of the massive parallel sequencers for sequencing projects of a moderate number of amplicons (50-500) with typical applications in resequencing exons in positional or functional candidate regions and molecular genetic diagnostics. Hum Mutat 0,1-6, 2008.
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