Whole genome sequence analysis suggests intratumoral heterogeneity in dissemination of breast cancer to lymph nodes.

BACKGROUND: Intratumoral heterogeneity may help drive resistance to targeted therapies in cancer. In breast cancer, the presence of nodal metastases is a key indicator of poorer overall survival. The aim of this study was to identify somatic genetic alterations in early dissemination of breast cancer by whole genome next generation sequencing (NGS) of a primary breast tumor, a matched locally-involved axillary lymph node and healthy normal DNA from blood. METHODS: Whole genome NGS was performed on 12 µg (range 11.1-13.3 µg) of DNA isolated from fresh-frozen primary breast tumor, axillary lymph node and peripheral blood following the DNA nanoball sequencing protocol. Single nucleotide variants, insertions, deletions, and substitutions were identified through a bioinformatic pipeline and compared to CIN25, a key set of genes associated with tumor metastasis. RESULTS: Whole genome sequencing revealed overlapping variants between the tumor and node, but also variants that were unique to each. Novel mutations unique to the node included those found in two CIN25 targets, TGIF2 and CCNB2, which are related to transcription cyclin activity and chromosomal stability, respectively, and a unique frameshift in PDS5B, which is required for accurate sister chromatid segregation during cell division. We also identified dominant clonal variants that progressed from tumor to node, including SNVs in TP53 and ARAP3, which mediates rearrangements to the cytoskeleton and cell shape, and an insertion in TOP2A, the expression of which is significantly associated with tumor proliferation and can segregate breast cancers by outcome. CONCLUSION: This case study provides preliminary evidence that primary tumor and early nodal metastasis have largely overlapping somatic genetic alterations. There were very few mutations unique to the involved node. However, significant conclusions regarding early dissemination needs analysis of a larger number of patient samples

Global Gene Expression Profiling Of Human Pleural Mesotheliomas: Identification of Matrix Metalloproteinase 14 (MMP-14) as Potential Tumour Target

BACKGROUND:The goal of our study was to molecularly dissect mesothelioma tumour pathways by mean of microarray technologies in order to identify new tumour biomarkers that could be used as early diagnostic markers and possibly as specific molecular therapeutic targets. METHODOLOGY:We performed Affymetrix HGU133A plus 2.0 microarray analysis, containing probes for about 39,000 human transcripts, comparing 9 human pleural mesotheliomas with 4 normal pleural specimens. Stringent statistical feature selection detected a set of differentially expressed genes that have been further evaluated to identify potential biomarkers to be used in early diagnostics. Selected genes were confirmed by RT-PCR. As reported by other mesothelioma profiling studies, most of genes are involved in G2/M transition. Our list contains several genes previously described as prognostic classifier. Furthermore, we found novel genes, never associated before to mesotheliom that could be involved in tumour progression. Notable is the identification of MMP-14, a member of matrix metalloproteinase family. In a cohort of 70 mesothelioma patients, we found by a multivariate Cox regression analysis, that the only parameter influencing overall survival was expression of MMP14. The calculated relative risk of death in MM patients with low MMP14 expression was significantly lower than patients with high MMp14 expression (P = 0.002). CONCLUSIONS:Based on the results provided, this molecule could be viewed as a new and effective therapeutic target to test for the cure of mesothelioma

Characteristics of an autogenous single pass electron beam weld in thick gage CA6NM steel

CA6NM is a low carbon martensitic stainless steel that is widely applied in hydroelectric turbine manufacturing. Using conventional fusion welding techniques, the fabrication of a thick section in CA6NM requires a V-groove joint design and multiple passes to achieve the required penetration. However, exposure to a substantial heat input through this process renders large fusion and heat-affected zones, microstructural variations, as well as distortion of the assembly, which pose difficulties for the manufacture and performance of the component. The application of a high energy density technique, namely electron beam (EB) welding, was used in the present work to penetrate a 60-mm-thick section in CA6NM with a single pass without filler metal. To prevent cracking in the weldment, the CA6NM was heated to 100\u2013170 \ub0C before EB welding using a zonal preheat treatment, which was applied in situ using a defocused beam. The as-welded CA6NM exhibited a narrow fusion zone (FZ) and a series of distinct yet very small heat-affected zones (HAZ) with different microstructural characteristics. As compared to the base metal (BM) hardness of 289 \ub1 4 HV, the EB weldment exhibited a hardness maximum of 425 HV in the HAZs and an average hardness of 395 \ub1 6 HV in the FZ. Post-weld heat treatment (PWHT) was effective in lowering the hardness in the FZ of the EB weldment to a mean value of 346 \ub1 13 HV.Peer reviewed: YesNRC publication: Ye

Impact of EGFRA289T/V mutation on relapse pattern in glioblastoma

International audienceMolecular factors influence relapse patterns in glioblastoma. The hotspot mutation located at position 289 of the extracellular domain of the epidermal growth factor receptor (EGFRA289mut) is associated with a more infiltrative phenotype. The primary objective of this study was to explore the impact of the EGFRA289 mutation on the pattern of relapse after chemoradiotherapy-based treatment of patients suffering from newly diagnosed glioblastoma