Topographic analysis of pancreatic cancer by TMA and digital spatial profiling reveals biological complexity with potential therapeutic implications.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal human malignancies. Tissue microarrays (TMA) are an established method of high throughput biomarker interrogation in tissues but may not capture histological features of cancer with potential biological relevance. Topographic TMAs (T-TMAs) representing pathophysiological hallmarks of cancer were constructed from representative, retrospective PDAC diagnostic material, including 72 individual core tissue samples.

Immunoglobulin/T Cell Receptor Capture Strategy for Comprehensive Immunogenetics.

In the era of genomic medicine, targeted next generation sequencing strategies (NGS) are becoming increasingly adopted by clinical molecular diagnostic laboratories to identify genetic diagnostic and prognostic biomarkers in hemato-oncology. We describe the EuroClonality-NGS DNA Capture (EuroClonality-NDC) assay, which is designed to simultaneously detect B and T cell clonal rearrangements, translocations, copy number alterations, and sequence variants. The accompanying validated bioinformatics pipeline enables production of an integrated report.

The Potential of Digital Image Analysis to Determine Tumor Cell Content in Biobanked Formalin-Fixed, Paraffin-Embedded Tissue Samples.

Best practices dictate that biobanks ensure accurate determination of tumor content before supplying formalin-fixed, paraffin-embedded (FFPE) tissue samples to researchers for nucleic acid extraction and downstream molecular testing. It is advisable that trained and competent individuals, who understand the requirements of the downstream molecular tests, perform the microscopic morphological examination. However, the special skills, time, and costs associated with these assessments can be prohibitive, especially in large case cohorts requiring extensive pathological review.

LINE retrotransposons characterize mammalian tissue-specific and evolutionarily dynamic regulatory regions.

Background: To investigate the mechanisms driving regulatory evolution across tissues, we experimentally mapped promoters, enhancers, and gene expression in the liver, brain, muscle, and testis from ten diverse mammals.

Results: The regulatory landscape around genes included both tissue-shared and tissue-specific regulatory regions, where tissue-specific promoters and enhancers evolved most rapidly. Genomic regions switching between promoters and enhancers were more common across species, and less common across tissues within a single species.

Detection of Structural Variants in Circulating Cell-Free DNA from Sarcoma Patients Using Next Generation Sequencing.

Circulating tumour DNA (ctDNA) analysis using next generation sequencing (NGS) is being implemented in clinical practice for treatment stratification and disease monitoring. However, using ctDNA to detect structural variants, a common occurrence in sarcoma, can be challenging. Here, we use a sarcoma-specific targeted NGS panel to identify translocations and copy number variants in a cohort of 12 tissue specimens and matched circulating cell-free DNA (cfDNA) from soft tissue sarcoma patients, including alveolar rhabdomyosarcoma ( = 2), Ewing's Sarcoma ( = 2), synovial sarcoma ( = 2), extraskeletal myxoid chondrosarcoma ( = 1), clear cell sarcoma ( = 1), undifferentiated round cell sarcoma ( = 1), myxoid liposarcoma ( = 1), alveolar soft part cell sarcoma ( = 1) and dedifferentiated liposarcoma ( = 1).

Proteogenomics and Hi-C reveal transcriptional dysregulation in high hyperdiploid childhood acute lymphoblastic leukemia.

Hyperdiploidy, i.e. gain of whole chromosomes, is one of the most common genetic features of childhood acute lymphoblastic leukemia (ALL), but its pathogenetic impact is poorly understood.

NF-κB-Dependent Lymphoid Enhancer Co-option Promotes Renal Carcinoma Metastasis.

Metastases, the spread of cancer cells to distant organs, cause the majority of cancer-related deaths. Few metastasis-specific driver mutations have been identified, suggesting aberrant gene regulation as a source of metastatic traits. However, how metastatic gene expression programs arise is poorly understood.

Hi-C as a tool for precise detection and characterisation of chromosomal rearrangements and copy number variation in human tumours.

Chromosomal rearrangements occur constitutionally in the general population and somatically in the majority of cancers. Detection of balanced rearrangements, such as reciprocal translocations and inversions, is troublesome, which is particularly detrimental in oncology where rearrangements play diagnostic and prognostic roles. Here we describe the use of Hi-C as a tool for detection of both balanced and unbalanced chromosomal rearrangements in primary human tumour samples, with the potential to define chromosome breakpoints to bp resolution.

Genetic Analysis of 'PAX6-Negative' Individuals with Aniridia or Gillespie Syndrome.

We report molecular genetic analysis of 42 affected individuals referred with a diagnosis of aniridia who previously screened as negative for intragenic PAX6 mutations. Of these 42, the diagnoses were 31 individuals with aniridia and 11 individuals referred with a diagnosis of Gillespie syndrome (iris hypoplasia, ataxia and mild to moderate developmental delay). Array-based comparative genomic hybridization identified six whole gene deletions: four encompassing PAX6 and two encompassing FOXC1.

A Potential Contributory Role for Ciliary Dysfunction in the 16p11.2 600 kb BP4-BP5 Pathology.

The 16p11.2 600 kb copy-number variants (CNVs) are associated with mirror phenotypes on BMI, head circumference, and brain volume and represent frequent genetic lesions in autism spectrum disorders (ASDs) and schizophrenia. Here we interrogated the transcriptome of individuals carrying reciprocal 16p11.

The impact of chromosomal rearrangements on regulation of gene expression.

The effects that coding region single-nucleotide polymorphisms or mutations have on gene expression have been well documented, predominantly owing to their association with disease. The effects of structural chromosomal rearrangements are also receiving increasing attention with the development of new techniques that allow accurate, high-resolution data, whether genomic interaction or transcriptome data, to be generated right down to the single-cell level. Over the past 18 months, these advances in experimental techniques have been used to further confirm and delineate the substantial effects that chromosome rearrangements can have on the regulation of gene expression and provide evidence of direct links between the two.

Structural variation-associated expression changes are paralleled by chromatin architecture modifications.

Unlabelled: Copy number variants (CNVs) influence the expression of genes that map not only within the rearrangement, but also to its flanks. To assess the possible mechanism(s) underlying this "neighboring effect", we compared intrachromosomal interactions and histone modifications in cell lines of patients affected by genomic disorders and control individuals. Using chromosome conformation capture (4C-seq), we observed that a set of genes flanking the Williams-Beuren Syndrome critical region (WBSCR) were often looping together.

A 600 kb deletion syndrome at 16p11.2 leads to energy imbalance and neuropsychiatric disorders.

Background: The recurrent ~600 kb 16p11.2 BP4-BP5 deletion is among the most frequent known genetic aetiologies of autism spectrum disorder (ASD) and related neurodevelopmental disorders.

Objective: To define the medical, neuropsychological, and behavioural phenotypes in carriers of this deletion.

Multifocal epithelial tumors and field cancerization from loss of mesenchymal CSL signaling.

It is currently unclear whether tissue changes surrounding multifocal epithelial tumors are a cause or consequence of cancer. Here, we provide evidence that loss of mesenchymal Notch/CSL signaling causes tissue alterations, including stromal atrophy and inflammation, which precede and are potent triggers for epithelial tumors. Mice carrying a mesenchymal-specific deletion of CSL/RBP-Jκ, a key Notch effector, exhibit spontaneous multifocal keratinocyte tumors that develop after dermal atrophy and inflammation.

Structural variation and its effect on expression.

Structural variation, whether it is caused by copy number variants or present in a balanced form, such as reciprocal translocations and inversions, can have a profound and dramatic effect on the expression of genes mapping within and close to the rearrangement, as well as affecting others genome wide. These effects can be caused by altering the copy number of one or more genes or regulatory elements (dosage effect) or from physical disruption of links between regulatory elements and their associated gene or genes, resulting in perturbation of expression. Similarly, large-scale structural variants can result in genome-wide expression changes by altering the positions that chromosomes occupy within the nucleus, potentially disrupting not only local cis interactions, but also trans interactions that occur throughout the genome.

Esrrg functions in early branch generation of the ureteric bud and is essential for normal development of the renal papilla.

Congenital anomalies of the kidney and urinary tract (CAKUTs) are common disorders of human development affecting the renal parechyma, renal pelvis, ureter, bladder and urethra; they show evidence of shared genetic aetiology, although the molecular basis of this remains unknown in the majority of cases. Breakpoint mapping of a de novo, apparently balanced, reciprocal translocation associated with bilateral renal agenesis has implicated the gene encoding the nuclear steroid hormone receptor ESRRG as a candidate gene for CAKUT. Here we show that the Esrrg protein is detected throughout early ureteric ducts as cytoplasmic/sub-membranous staining; with nuclear localization seen in developing nephrons.

Bilateral renal agenesis/hypoplasia/dysplasia (BRAHD): postmortem analysis of 45 cases with breakpoint mapping of two de novo translocations.

Background: Bilateral renal agenesis/hypoplasia/dysplasia (BRAHD) is a relatively common, lethal malformation in humans. Established clinical risk factors include maternal insulin dependent diabetes mellitus and male sex of the fetus. In the majority of cases, no specific etiology can be established, although teratogenic, syndromal and single gene causes can be assigned to some cases.

The effect of translocation-induced nuclear reorganization on gene expression.

Translocations are known to affect the expression of genes at the breakpoints and, in the case of unbalanced translocations, alter the gene copy number. However, a comprehensive understanding of the functional impact of this class of variation is lacking. Here, we have studied the effect of balanced chromosomal rearrangements on gene expression by comparing the transcriptomes of cell lines from controls and individuals with the t(11;22)(q23;q11) translocation.

'Crommelin-type' symmetrical tetramelic reduction deformity: a new case and breakpoint mapping of a reported case with de-novo t(2;12)(p25.1;q23.3).

We report a male fetus with symmetrical peromelic reduction of the upper limbs (missing distal, mesial and proximal elements) and symmetrical phocomelic reduction of the lower limbs (missing proximal and mesial elements) without other major malformations. We identified 11 previously reported cases with very similar features and have named this entity 'Crommelin-type' symmetrical tetramelic reduction deformity. Interphase fluorescence in-situ hybridization on isolated nuclei from paraffin-embedded tissue was used to map the breakpoints in a previously reported case with a de-novo t(2;12)(p25.

Side effects of genome structural changes.

The first extensive catalog of structural human variation was recently released. It showed that large stretches of genomic DNA that vary considerably in copy number were extremely abundant. Thus it is conceivable that they play a major role in functional variation.

A diminutive chromosome 21 centromere in acute lymphoblastic leukemia.

A chance observation of a tiny constitutional variant for the centromere of chromosome 21 in two patients with acute lymphoblastic leukemia (ALL), suggested a possible correlation with the cytogenetic findings in their leukemic cells. Interphase FISH revealed three 13/21 centromeric signals and a single MLL signal in the blast cells of each patient. Metaphase FISH with dual-color application of whole-chromosome paint (wcp) and centromeric probes for chromosome 21 showed two copies of chromosome 21, one with a tiny centromeric signal which corresponded to the invisible centromere in the interphase cells.

Interphase molecular cytogenetic screening for chromosomal abnormalities of prognostic significance in childhood acute lymphoblastic leukaemia: a UK Cancer Cytogenetics Group Study.

Summary Interphase fluorescence in situ hybridization (iFISH) was used independently to reveal chromosomal abnormalities of prognostic importance in a large, consecutive series of children (n = 2367) with acute lymphoblastic leukaemia (ALL). The fusions, TEL/AML1 and BCR/ABL, and rearrangements of the MLL gene occurred at frequencies of 22% (n = 447/2027) (25% in B-lineage ALL), 2% (n = 43/2027) and 2% (n = 47/2016) respectively. There was considerable variation in iFISH signal patterns both between and within patient samples.

Translocations of 14q32 and deletions of 13q14 are common chromosomal abnormalities in systemic amyloidosis.

Systemic monoclonal immunoglobulin light chain amyloidosis (AL) is associated with clonal plasma cell dyscrasias that are often subtle and non-proliferating. AL shares numerical chromosomal changes with multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS). Illegitimate translocations involving the immunoglobulin heavy chain gene (IGH) at 14q32 and deletions of the long arm of chromosome 13, [del(13q)], commonly occur in MM, MGUS and plasma cell leukaemia.