High Accuracy Mutation Detection in Leukemia on a Selected Panel of Cancer Genes

<div><p>With the advent of whole-genome and whole-exome sequencing, high-quality catalogs of recurrently mutated cancer genes are becoming available for many cancer types. Increasing access to sequencing technology, including bench-top sequencers, provide the opportunity to re-sequence a limited set of cancer genes across a patient cohort with limited processing time. Here, we re-sequenced a set of cancer genes in T-cell acute lymphoblastic leukemia (T-ALL) using Nimblegen sequence capture coupled with Roche/454 technology. First, we investigated how a maximal sensitivity and specificity of mutation detection can be achieved through a benchmark study. We tested nine combinations of different mapping and variant-calling methods, varied the variant calling parameters, and compared the predicted mutations with a large independent validation set obtained by capillary re-sequencing. We found that the combination of two mapping algorithms, namely <em>BWA-SW</em> and <em>SSAHA2</em>, coupled with the variant calling algorithm <em>Atlas-SNP2</em> yields the highest sensitivity (95%) and the highest specificity (93%). Next, we applied this analysis pipeline to identify mutations in a set of 58 cancer genes, in a panel of 18 T-ALL cell lines and 15 T-ALL patient samples. We confirmed mutations in known T-ALL drivers, including PHF6, NF1, FBXW7, NOTCH1, KRAS, NRAS, PIK3CA, and PTEN. Interestingly, we also found mutations in several cancer genes that had not been linked to T-ALL before, including JAK3. Finally, we re-sequenced a small set of 39 candidate genes and identified recurrent mutations in TET1, SPRY3 and SPRY4. In conclusion, we established an optimized analysis pipeline for Roche/454 data that can be applied to accurately detect gene mutations in cancer, which led to the identification of several new candidate T-ALL driver mutations.</p> </div

Early deprivation as a risk factor for narcissistic identity pathologies in adolescence with regard to international adoption

The current study is a psychoanalytic reading of the clinical material arising from ongoing developmental research into international adoption within the framework of the Attachment Adoption Research Network (AAARN). The primary objective of the study is to verify whether the severity of deprivation experienced preadoption is a risk factor for narcissistic identity pathologies in adolescence with regard to international adoption. A grounded theory approach is used to identify a set of qualitative variables, which are later quantitatively assessed. The findings are discussed in terms of both qualitative and quantitative results and suggest the greater presence of chronic somatic troubles and observable signs of primary trauma in the adoption population compared to the control group. Future areas for research are suggested in the conclusion

DUTCH DENTISTS DECISIONS TO TAKE BITEWING RADIOGRAPHS

A postal questionnaire was sent to a 10% (n = 444) national random sample of Dutch dental practitioners. The response was 77% (n = 344). The practitioners prescribed bitewings on average for 57% of “new” 25‐yr‐old patients. Five significant (P < 0.05) variables explained 24% of the variation in bitewing prescribing for these “new” patients. These were, in declining level of importance: the initial dental condition of the patient, the proportion of restorative treatment decisions based solely on radiographs, the level of urbanization of the practice location, the technical level of the practice equipment and the importance attached by dentists to the diagnostic use of dental floss for imerproximal caries diagnosis. The low power of the regression model in explaining variation in the decision to take bitewings indicates an idiosyncratic use of bitewing radiographs for caries diagnosis. A weak tendency to adopt different diagnostic sets of procedures was demonstrated

Malt1 self-cleavage is critical for regulatory T cell homeostasis and anti-tumor immunity in mice

Mucosa-associated lymphoid tissue 1 (Malt1) regulates immune cell function by mediating the activation of nuclear factor κB (NF-κB) signaling through both its adaptor and proteolytic function. Malt1 is also a target of its own protease activity and this self-cleavage further contributes to NF-κB activity. Until now, the functional distinction between Malt1 self-cleavage and its general protease function in regulating NF-κB signaling and immune activation remained unclear. Here we demonstrate, using a new mouse model, the importance of Malt1 self-cleavage in regulating expression of NF-κB target genes and subsequent T cell activation. Significantly, we further establish that Treg homeostasis is critically linked to Malt1 function via a Treg intrinsic and extrinsic mechanism. TCR-mediated Malt1 proteolytic activity and self-cleavage was found to drive Il2 expression in conventional CD4 + T cells, thereby regulating Il2 availability for Treg homeostasis. Remarkably, the loss of Malt1-mediated self-cleavage alone was sufficient to cause a significant Treg deficit resulting in increased anti-tumor immune reactivity without associated autoimmunity complications. These results establish for the first time that inhibition of MALT1 proteolytic activity could be a viable therapeutic strategy to augment anti-tumor immunity

Hedgehog pathway activation in T-cell acute lymphoblastic leukemia predicts response to SMO and GLI1 inhibitors

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive childhood leukemia that is caused by the accumulation of multiple genomic lesions resulting in transcriptional deregulation and increased cell proliferation and survival. Through analysis of gene expression data, we provide evidence that the hedgehog pathway is activated in 20% of T-ALL samples. Hedgehog pathway activation is associated with ectopic expression of the hedgehog ligands Sonic hedgehog (SHH) or Indian hedgehog (IHH), and with upregulation of the transcription factor GLI1 Ectopic expression of SHH or IHH in mouse T cells in vivo caused hedgehog pathway activation in both lymphoid and epithelial cells in the thymus and resulted in increased expression of important T-cell stimulatory ligands (Dll4, Il7, and Vegf) by thymic epithelial cells. In T-ALL cell lines, pharmacological inhibition or short interfering RNA-mediated knockdown of SMO or GLI1 led to decreased cell proliferation. Moreover, primary T-ALL cases with high GLI1 messenger RNA levels, but not those with low or undetectable GLI1 expression, were sensitive to hedgehog pathway inhibition by GANT61 or GDC-0449 (vismodegib) using ex vivo cultures and in vivo xenograft models. We identify the hedgehog pathway as a novel therapeutic target in T-ALL and demonstrate that hedgehog inhibitors approved by the US Food and Drug Administration could be used for the treatment of this rare leukemia.status: publishe