A CRISPR Dropout Screen Identifies Genetic Vulnerabilities and Therapeutic Targets in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive cancer with a poor prognosis, for which mainstream treatments have not changed for decades. To identify additional therapeutic targets in AML, we optimize a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) screening platform and use it to identify genetic vulnerabilities in AML cells. We identify 492 AML-specific cell-essential genes, including several established therapeutic targets such as $\textit{DOT1L}$, $\textit{BCL2}$, and $\textit{MEN1}$, and many other genes including clinically actionable candidates. We validate selected genes using genetic and pharmacological inhibition, and chose $\textit{KAT2A}$ as a candidate for downstream study. $\textit{KAT2A}$ inhibition demonstrated anti-AML activity by inducing myeloid differentiation and apoptosis, and suppressed the growth of primary human AMLs of diverse genotypes while sparing normal hemopoietic stem-progenitor cells. Our results propose that KAT2A inhibition should be investigated as a therapeutic strategy in AML and provide a large number of genetic vulnerabilities of this leukemia that can be pursued in downstream studies.This work was funded by the Kay Kendall Leukaemia Fund (KKLF) and the Wellcome Trust (WT098051). G.S.V. is funded by a Wellcome Trust Senior Fellowship in Clinical Science (WT095663MA) and work in his laboratory is funded by Bloodwise. C.P. is funded by a Kay Kendall Leukaemia Fund Intermediate Fellowship (KKL888)

SRPK1 maintains acute myeloid leukemia through effects on isoform usage of epigenetic regulators including BRD4.

We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL-rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB, BRD4 and MED24. We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC. We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML

Autosomal recessive cerebellar ataxias

Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000), ataxia-telangiectasia (1–2.5/100,000) and early onset cerebellar ataxia with retained tendon reflexes (1/100,000). Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder), ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED), aprataxin in ataxia with oculomotor apraxia (AOA1), and senataxin in ataxia with oculomotor apraxia (AOA2). Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning), electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia

Promoter-bound METTL3 maintains myeloid leukaemia by m6A-dependent translation control.

N6-methyladenosine (m6A) is an abundant internal RNA modification in both coding and non-coding RNAs that is catalysed by the METTL3-METTL14 methyltransferase complex. However, the specific role of these enzymes in cancer is still largely unknown. Here we define a pathway that is specific for METTL3 and is implicated in the maintenance of a leukaemic state. We identify METTL3 as an essential gene for growth of acute myeloid leukaemia cells in two distinct genetic screens. Downregulation of METTL3 results in cell cycle arrest, differentiation of leukaemic cells and failure to establish leukaemia in immunodeficient mice. We show that METTL3, independently of METTL14, associates with chromatin and localizes to the transcriptional start sites of active genes. The vast majority of these genes have the CAATT-box binding protein CEBPZ present at the transcriptional start site, and this is required for recruitment of METTL3 to chromatin. Promoter-bound METTL3 induces m6A modification within the coding region of the associated mRNA transcript, and enhances its translation by relieving ribosome stalling. We show that genes regulated by METTL3 in this way are necessary for acute myeloid leukaemia. Together, these data define METTL3 as a regulator of a chromatin-based pathway that is necessary for maintenance of the leukaemic state and identify this enzyme as a potential therapeutic target for acute myeloid leukaemia

Оценка эффективности комплекса методов медицинской реабилитации пациентов с двигательной дисфункцией кисти вследствие острых нарушений мозгового кровообращения

МЕДИЦИНСКАЯ РЕАБИЛИТАЦИЯКИСТЬ РУКИКИСТЬПСИХОМОТОРНАЯ АКТИВНОСТЬДВИГАТЕЛЬНЫХ НАВЫКОВ РАССТРОЙСТВА /РЕАБИЛРЕАБИЛИТАЦИЯ /МЕТОДЫМОЗГОВОГО КРОВООБРАЩЕНИЯ РАССТРОЙСТВА /ОСЛ /РЕАБИЛЛЕЧЕБНАЯ ГИМНАСТИКАМЕЛКАЯ МОТОРИКАЦелью исследования являлось изучение эффективности комплекса медицинской реабилитации, разработанного на основе зеркальной визуальной обратной связи, элементов двигательной терапии индуцированным ограничением, метода тренировки двигательных навыков кисти с использованием латексных резинок и авторского метода тренировки мелких моторных навыков у пациентов с двигательной дисфункцией кисти вследствие острого нарушения мозгового кровообращения различной степени выраженности. В исследовании приняли участие 62 пациента, разделенные на 2 группы сравнения, сопоставимые по полу, возрасту, реабилитационному периоду и потенциалу. Для анализа результатов использовались методы оценки эффективности медицинской реабилитации пациентов с двигательной дисфункцией кисти, утвержденные министерством здравоохранения Республики Беларусь. По результатам исследования было выявлено межгрупповое различие в восстановлении мелкой моторики, показателей кистевой динамометрии, уровне самооценки пациентом утраты функции верхней конечности, степени выраженности тревожной и депрессивной симптоматики, проявляющееся в более качественном результате у пациентов клинической группы. Также выявлено преобладание увеличений показателей и при оценке качества жизни у респондентов, проходящих предложенный комплекс методов медицинской реабилитации над пациентами контрольной группы. Разработанный комплекс, в условиях применения в соответствии с алгоритмом, позволяет более качественно по сравнению с пациентами, проходящими стандартный курс медицинской реабилитации, восстановить двигательный навык, утраченный вследствие острого нарушения мозгового кровообращения, улучшить степень самообслуживания, качества жизни и приводит к снижению выраженности тревожно-депрессивной симптоматики.Objectives. To study the efficacy of the medical rehabilitation complex developed on the basis of mirror visual feedback, elements of constraint induced movement therapy, the method of hand motor skills’ training with the use of latex rubber bands and the author’s own method of fine motor skills training in patients with motor dysfunction of the hand caused by acute cerebral circulation of different severity degree. Material and methods. The study involved 62 patients, divided into 2 comparison groups, matched by sex, age, rehabilitation period, and potential. To analyze the results we used methods for assessing the effectiveness of medical rehabilitation of patients with motor dysfunction of the hand, which were approved by the Ministry of Health of the Republic of Belarus. Results. The study revealed an intergroup difference in restoring fine motor skills, hand dynamometry indices, the patient’s self-assessment of the upper limb function loss, the severity of anxiety and depression symptoms, which manifests itself in a better result in patients of the clinical group. The prevalence of the increased indicators was also revealed when assessing the life quality of respondents undergoing the proposed complex of medical rehabilitation methods over patients of the control group. Conclusions. The developed complex, in terms of application in accordance with the algorithm, allows more qualitatively compared with patients undergoing a standard course of medical rehabilitation, to restore the motor skill lost because of acute cerebral circulation disturbance, to improve the degree of self-care, quality of life and leads to a decrease in anxiety-depression symptoms