Nature cell biology, 2020
Martinez-Høyer, Sergio, Deng, Yu, Parker, Jeremy, Jiang, Jihong, Mo, Angela, Docking, T Roderick, Gharaee, Nadia, Li, Jenny, Umlandt, Patricia, Fuller, Megan, Jädersten, Martin, Kulasekararaj, Austin, Malcovati, Luca, List, Alan F, Hellström-Lindberg, Eva, Platzbecker, Uwe, Karsan, Aly
Interstitial deletion of the long arm of chromosome 5 (del(5q)) is the most common structural genomic variant in myelodysplastic syndromes (MDS){{sup}}1{{/sup}}. Lenalidomide (LEN) is the treatment of choice for patients with del(5q) MDS, but half of the responding patients become resistant{{sup}}2{{/sup}} within 2 years. TP53 mutations are detected in ~20% of LEN-resistant patients{{sup}}3{{/sup}}. Here we show that patients who become resistant to LEN harbour recurrent variants of TP53 or RUNX1. LEN upregulated RUNX1 protein and function in a CRBN- and TP53-dependent manner in del(5q) cells, and mutation or downregulation of RUNX1 rendered cells resistant to LEN. LEN induced megakaryocytic differentiation of del(5q) cells followed by cell death that was dependent on calpain activation and CSNK1A1 degradation{{sup}}4,5{{/sup}}. We also identified GATA2 as a LEN-responsive gene that is required for LEN-induced megakaryocyte differentiation. Megakaryocytic gene-promoter analyses suggested that LEN-induced degradation of IKZF1 enables a RUNX1-GATA2 complex to drive megakaryocytic differentiation. Overexpression of GATA2 restored LEN sensitivity in the context of RUNX1 or TP53 mutations by enhancing LEN-induced megakaryocytic differentiation. Screening for mutations that block LEN-induced megakaryocytic differentiation should identify patients who are resistant to LEN.
Nature medicine, 2010
Starczynowski, Daniel T, Kuchenbauer, Florian, Argiropoulos, Bob, Sung, Sandy, Morin, Ryan, Muranyi, Andrew, Hirst, Martin, Hogge, Donna, Marra, Marco, Wells, Richard A, Buckstein, Rena, Lam, Wan, Humphries, R Keith, Karsan, Aly
5q- syndrome is a subtype of myelodysplastic syndrome characterized by severe anemia and variable neutropenia but normal or high platelet counts with dysplastic megakaryocytes. We examined expression of microRNAs (miRNAs) encoded on chromosome 5q as a possible cause of haploinsufficiency. We show that deletion of chromosome 5q correlates with loss of two miRNAs that are abundant in hematopoietic stem/progenitor cells (HSPCs), miR-145 and miR-146a, and we identify Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP) and tumor necrosis factor receptor-associated factor-6 (TRAF6) as respective targets of these miRNAs. TIRAP is known to lie upstream of TRAF6 in innate immune signaling. Knockdown of miR-145 and miR-146a together or enforced expression of TRAF6 in mouse HSPCs resulted in thrombocytosis, mild neutropenia and megakaryocytic dysplasia. A subset of mice transplanted with TRAF6-expressing marrow progressed either to marrow failure or acute myeloid leukemia. Thus, inappropriate activation of innate immune signals in HSPCs phenocopies several clinical features of 5q- syndrome.
The Journal of molecular diagnostics : JMD, 2019
Parker, Jeremy D K, Yap, Shyong Quin, Starks, Elizabeth, Slind, Jillian, Swanson, Lucas, Docking, T Roderick, Fuller, Megan, Zhou, Chen, Walker, Blair, Filipenko, Douglas, Xiong, Wei, Karimuddin, Ahmer A, Phang, P Terry, Raval, Manoj, Brown, Carl J, Karsan, Aly
Formalin fixation is the standard method for the preservation of tissue for diagnostic purposes, including pathologic review and molecular assays. However, this method is known to cause artifacts that can affect the accuracy of molecular genetic test results. We assessed the applicability of alternative fixatives to determine whether these perform significantly better on next-generation sequencing assays, and whether adequate morphology is retained for primary diagnosis, in a prospective study using a clinical-grade, laboratory-developed targeted resequencing assay. Several parameters relating to sequencing quality and variant calling were examined and quantified in tumor and normal colon epithelial tissues. We identified an alternative fixative that suppresses many formalin-related artifacts while retaining adequate morphology for pathologic review.
The Journal of molecular diagnostics : JMD, 2020
Moore, Richard A, Zeng, Thomas, Docking, T Roderick, Bosdet, Ian, Butterfield, Yaron S, Munro, Sarah, Li, Irene, Swanson, Lucas, Starks, Elizabeth R, Tse, Kane, Mungall, Andrew J, Holt, Robert A, Karsan, Aly
Sample tracking and identity are essential when processing multiple samples in parallel. Sequencing applications often involve high sample numbers, and the data are frequently used in a clinical setting. As such, a simple and accurate intrinsic sample tracking process through a sequencing pipeline is essential. Various solutions have been implemented to verify sample identity, including variant detection at the start and end of the pipeline using arrays or genotyping, bioinformatic comparisons, and optical barcoding of samples. None of these approaches are optimal. To establish a more effective approach using genetic barcoding, we developed a panel of unique DNA sequences cloned into a common vector. A unique DNA sequence is added to the sample when it is first received and can be detected by PCR and/or sequencing at any stage of the process. The control sequences are approximately 200 bases long with low identity to any sequence in the National Center for Biotechnology Information nonredundant database (<30 bases) and contain no long homopolymer (>7) stretches. When a spiked next-generation sequencing library is sequenced, sequence reads derived from this control sequence are generated along with the standard sequencing run and are used to confirm sample identity and determine cross-contamination levels. This approach is used in our targeted clinical diagnostic whole-genome and RNA-sequencing pipelines and is an inexpensive, flexible, and platform-agnostic solution.
Cell reports, 2019
Coulombe, Patrick, Paliouras, Grigorios N, Clayton, Ashley, Hussainkhel, Angela, Fuller, Megan, Jovanovic, Vida, Dauphinee, Shauna, Umlandt, Patricia, Xiang, Ping, Kyle, Alistair H, Minchinton, Andrew I, Humphries, R Keith, Hoodless, Pamela A, Parker, Jeremy D K, Wright, Joanne L, Karsan, Aly
The sterile alpha motif (SAM) and SRC homology 3 (SH3) domain containing protein 1 (Sash1) acts as a scaffold in TLR4 signaling. We generated Sash1{{sup}}-/-{{/sup}} mice, which die in the perinatal period due to respiratory distress. Constitutive or endothelial-restricted Sash1 loss leads to a delay in maturation of alveolar epithelial cells causing reduced surfactant-associated protein synthesis. We show that Sash1 interacts with β-arrestin 1 downstream of the TLR4 pathway to activate Akt and endothelial nitric oxide synthase (eNOS) in microvascular endothelial cells. Generation of nitric oxide downstream of Sash1 in endothelial cells affects alveolar epithelial cells in a cGMP-dependent manner, inducing maturation of alveolar type 1 and 2 cells. Thus, we identify a critical cell nonautonomous function for Sash1 in embryonic development in which endothelial Sash1 regulates alveolar epithelial cell maturation and promotes pulmonary surfactant production through nitric oxide signaling. Lung immaturity is a major cause of respiratory distress and mortality in preterm infants, and these findings identify the endothelium as a potential target for therapy.
International journal of laboratory hematology, 2019
Docking, T Roderick, Karsan, Aly
Clinical genetic testing in the myeloid malignancies is undergoing a rapid transition from the era of cytogenetics and single-gene testing to an era dominated by next-generation sequencing (NGS). This transition promises to better reveal the genetic alterations underlying disease, but there are distinct risks and benefits associated with different NGS testing platforms. NGS offers the potential benefit of being able to survey alterations across a wider set of genes, but analytic and clinical challenges associated with incidental findings, germ line variation, turnaround time, and limits of detection must be addressed. Additionally, transcriptome-based testing may offer several distinct benefits beyond traditional DNA-based methods. In addition to testing at disease diagnosis, research indicates potential benefits of genetic testing both prior to disease onset and at remission. In this review, we discuss the transition from the era of cytogenetics and single-gene tests to the era of NGS panels and genome-wide sequencing-highlighting both the potential and drawbacks of these novel technologies.
Nature communications, 2018
Lam, Jeffrey, van den Bosch, Marion, Wegrzyn, Joanna, Parker, Jeremy, Ibrahim, Rawa, Slowski, Kate, Chang, Linda, Martinez-Høyer, Sergio, Condorelli, Gianluigi, Boldin, Mark, Deng, Yu, Umlandt, Patricia, Fuller, Megan, Karsan, Aly
Expression of miR-143 and miR-145 is reduced in hematopoietic stem/progenitor cells (HSPCs) of myelodysplastic syndrome patients with a deletion in the long arm of chromosome 5. Here we show that mice lacking miR-143/145 have impaired HSPC activity with depletion of functional hematopoietic stem cells (HSCs), but activation of progenitor cells (HPCs). We identify components of the transforming growth factor β (TGFβ) pathway as key targets of miR-143/145. Enforced expression of the TGFβ adaptor protein and miR-145 target, Disabled-2 (DAB2), recapitulates the HSC defect seen in miR-143/145{{sup}}-/-{{/sup}} mice. Despite reduced HSC activity, older miR-143/145{{sup}}-/-{{/sup}} and DAB2-expressing mice show elevated leukocyte counts associated with increased HPC activity. A subset of mice develop a serially transplantable myeloid malignancy, associated with expansion of HPC. Thus, miR-143/145 play a cell context-dependent role in HSPC function through regulation of TGFβ/DAB2 activation, and loss of these miRNAs creates a preleukemic state.
Scientific reports, 2018
Agrahari, Rupesh, Foroushani, Amir, Docking, T Roderick, Chang, Linda, Duns, Gerben, Hudoba, Monika, Karsan, Aly, Zare, Habil
Network analysis is the preferred approach for the detection of subtle but coordinated changes in expression of an interacting and related set of genes. We introduce a novel method based on the analyses of coexpression networks and Bayesian networks, and we use this new method to classify two types of hematological malignancies; namely, acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Our classifier has an accuracy of 93%, a precision of 98%, and a recall of 90% on the training dataset (n = 366); which outperforms the results reported by other scholars on the same dataset. Although our training dataset consists of microarray data, our model has a remarkable performance on the RNA-Seq test dataset (n = 74, accuracy = 89%, precision = 88%, recall = 98%), which confirms that eigengenes are robust with respect to expression profiling technology. These signatures are useful in classification and correctly predicting the diagnosis. They might also provide valuable information about the underlying biology of diseases. Our network analysis approach is generalizable and can be useful for classifying other diseases based on gene expression profiles. Our previously published Pigengene package is publicly available through Bioconductor, which can be used to conveniently fit a Bayesian network to gene expression data.
