scholarly journals In vivo CRISPR/Cas9 knockout screen: TCEAL1 silencing enhances docetaxel efficacy in prostate cancer

2020 ◽  
Vol 3 (12) ◽  
pp. e202000770 ◽  
Author(s):  
Linda K Rushworth ◽  
Victoria Harle ◽  
Peter Repiscak ◽  
William Clark ◽  
Robin Shaw ◽  
...  

Docetaxel chemotherapy in metastatic prostate cancer offers only a modest survival benefit because of emerging resistance. To identify candidate therapeutic gene targets, we applied a murine prostate cancer orthograft model that recapitulates clinical invasive prostate cancer in a genome-wide CRISPR/Cas9 screen under docetaxel treatment pressure. We identified 17 candidate genes whose suppression may enhance the efficacy of docetaxel, with transcription elongation factor A–like 1 (Tceal1) as the top candidate. TCEAL1 function is not fully characterised; it may modulate transcription in a promoter dependent fashion. Suppressed TCEAL1 expression in multiple human prostate cancer cell lines enhanced therapeutic response to docetaxel. Based on gene set enrichment analysis from transcriptomic data and flow cytometry, we confirmed that loss of TCEAL1 in combination with docetaxel leads to an altered cell cycle profile compared with docetaxel alone, with increased subG1 cell death and increased polyploidy. Here, we report the first in vivo genome-wide treatment sensitisation CRISPR screen in prostate cancer, and present proof of concept data on TCEAL1 as a candidate for a combinational strategy with the use of docetaxel.

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2619-2619
Author(s):  
Katherine Dormon ◽  
Elda S Latif ◽  
Matthew Bashton ◽  
Deepali Pal ◽  
Matthew Selby ◽  
...  

Abstract Although paediatric acute lymphoblastic leukaemia (ALL) has a favourable prognosis, a number of cases will invariably relapse. One of the major problems associated with relapse is drug resistance, in particular to glucocorticoids, the mainstay of ALL treatment. Examining the underlying mechanisms is complicated by clonal heterogeneity within a patient and the potential impact of the leukaemic niche. To address mechanisms of drug resistance in a patient-relevant setting, we performed a genome-wide in vivo CRISPR screen in primary ALL material. To that end, we took advantage of primografted material from patient L707, who initially presented with a Dexamethasone (DEX) sensitive t(17;19) ALL, but relapsed 5 months after initial diagnosis. We transduced DEX sensitive presentation cells with the full genome GeCKOv2 CRISPR library, before transplantation into immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice. Mice were subsequently treated with DEX by oral gavage (15mg/kg for 5 weeks, 10mg/kg thereafter). DNA from several engrafted sites in the mouse was extracted and PCR amplified before being sequenced on the Illumina HiSeq2500. Changes in pool complexity were analysed using MaGEcK software to determine which sgRNAs were significantly enriched or depleted. By far the most significantly enriched sgRNAs were those targeting NR3C1, the gene encoding the glucocorticoid receptor. In addition, two of the top five significantly depleted sgRNAs targeted the Plexins, PLXNA1 and PLXND1. Whilst PLXNA1 is expressed at low levels, PLXND1 is highly expressed and has been linked to dexamethasone resistance. Notably, the matched relapsed material from L707 was highly DEX resistant both in tissue culture and when transplanted into NSG mice. SNP 6.0 analysis revealed a 5q deletion in the relapse, spanning 5 genes including NR3C1. Whole genome sequencing showed this was comprised of 2 deletions both targeting NR3C1, with different breakpoints for each allele. The differential gene expression between the L707 presentation and relapse established that NR3C1 was the most significant of all the genes lost at relapse, based on gene set enrichment analysis (GSEA). This contrasts with many ALL cases, where one of the downstream effectors of apoptosis is lost as opposed to NR3C1. Growth of the relapse material in vivo and in vitro was slower than the presentation in a competitive situation, but with DEX treatment the relapse phenotype began to emerge with a small percentage of cells showing a heterozygous deletion of NR3C1. These combined data strongly suggest that the NR3C1 deletion is the main driver of DEX resistance in the L707 relapse. Moreover, it proves that our in vivo CRISPR screen predicted the leukaemic relapse. These results confirm NR3C1 deletion as a driver in glucocorticoid resistance and demonstrate the power of in vivo CRISPR screens to predict mechanisms of gain of drug resistance and subsequent relapse. The parallels that can be drawn between the relapse and the CRISPR screen are striking, giving the indication that the progression from presentation to relapse may follow the same path in a patient derived xenograft setting as it did in the patient. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Marc Rickenbacher ◽  
Céline S Reinbold ◽  
Stefan Herms ◽  
Per Hoffmann ◽  
Sven Cichon ◽  
...  

Abstract Background: Postoperative cognitive dysfunction (POCD) is a common neurocognitive complication after surgery and anesthesia, particularly in elderly patients. Various studies have suggested genetic risk factors for POCD. The study aimed to detect genome-wide associations of POCD in older patients.Methods: In this prospective observational cohort study, participants aged ≥65 years completed a set of neuropsychological tests before, at 1 week, and 3 months after major noncardiac surgery. Test variables were converted into standard scores (z-scores) based on demographic characteristics. POCD was diagnosed if the decline was >1 standard deviation in ≥2 of the 15 variables in the assessment battery. A genome-wide association study (GWAS) was performed to determine potential alleles that are linked to the POCD phenotype. In addition, candidate genes for POCD were identified in a literature search for further analysis.Results: Sixty-three patients with blood samples were included in the study. POCD was diagnosed in 47.6% of patients at 1 week and in 34.2% of patients at 3 months after surgery. Insufficient sample quality led to exclusion of 26 patients. In the remaining 37 patients, a GWAS was performed, but no association (P < 5*10-8) with POCD was found. The subsequent gene set enrichment analysis of 34 candidate genes did not reveal any significant associations.Conclusion: In this patient cohort, a GWAS did not reveal an association between specific genetic alleles and POCD at 1 week and 3 months after surgery. Future genetic analysis should focus on specific candidate genes for POCD.Trial registration: ClinicalTrials.gov (NCT02864173)


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wandong Yu ◽  
Hangbin Ma ◽  
Junhong Li ◽  
Jinchao Ge ◽  
Pengyu Wang ◽  
...  

Abstract Background DDX52 is a type of DEAD/H box RNA helicase that was identified as a novel prostate cancer (PCa) genetic locus and possible causal gene in a European large-scale transcriptome-wide association study. However, the functions of DDX52 in PCa remain undetermined. The c-Myc oncogene plays a crucial role in the development of PCa, but the factors that regulate the activity of c-Myc in PCa are still unknown. Methods We determined DDX52 protein levels in PCa tissues using immunohistochemistry (IHC). DDX52 expression and survival outcomes in other PCa cohorts were examined using bioinformatics analysis. The inhibition of DDX52 via RNA interference with shRNA was used to clarify the effects of DDX52 on PCa cell growth in vitro and in vivo. Gene set enrichment analysis and RNA sequencing were used to explore the signaling regulated by DDX52 in PCa. Western blotting and IHC were used to determine the possible DDX52 signaling mechanism in PCa. Results DDX52 expression was upregulated in PCa tissues. Bioinformatics analysis showed that the level of DDX52 further increased in advanced PCa, with a high DDX52 level indicating a poor outcome. In vitro and in vivo experiments showed that downregulating DDX52 impeded the growth of PCa cells. High DDX52 levels contributed to activating c-Myc signaling in PCa patients and PCa cells. Furthermore, DDX52 expression was regulated by c-Myc and positively correlated with c-Myc expression in PCa. Conclusion DDX52 was overexpressed in PCa tissues in contrast to normal prostate tissues. DDX52 knockdown repressed the growth of PCa cells in vitro and in vivo. Deleting c-Myc inhibited DDX52 expression, which affected the activation of c-Myc signaling.


2021 ◽  
Author(s):  
Hans M. Dalton ◽  
Raghuvir Viswanatha ◽  
Ricky Brathwaite ◽  
Jae Sophia Zuno ◽  
Stephanie E. Mohr ◽  
...  

AbstractPartial loss-of-function mutations in glycosylation pathways underlie a set of rare diseases called Congenital Disorders of Glycosylation (CDGs). In particular, DPAGT1-CDG is caused by mutations in the gene encoding the first step in N-glycosylation, DPAGT1, and this disorder currently lacks effective therapies. To identify potential therapeutic targets for DPAGT1-CDG, we performed CRISPR knockout screens in Drosophila cells for genes associated with better survival and glycoprotein levels under DPAGT1 inhibition. We identified hundreds of candidate genes that may be of therapeutic benefit. Intriguingly, inhibition of the mannosyltransferase Dpm1, or its downstream glycosylation pathways, could rescue two in vivo models of DPAGT1 inhibition and ER stress, even though impairment of these pathways alone usually cause CDGs. While both in vivo models ostensibly cause ER stress (through DPAGT1 inhibition or a misfolded protein), we found a novel difference in fructose metabolism that may indicate glycolysis as a modulator of DPAGT1-CDG. Our results provide new therapeutic targets for DPAGT1-CDG, include the unique finding of Dpm1-related pathways rescuing DPAGT1 inhibition, and reveal a novel interaction between fructose metabolism and ER stress.


2017 ◽  
Vol 46 (2) ◽  
pp. 596-611 ◽  
Author(s):  
Yin Ni ◽  
Caiyun Song ◽  
Shuqing Jin ◽  
Zhoufeng Chen ◽  
Ming Ni ◽  
...  

Objective To explore stable and functional microRNA (miRNA)–disease relationships using a genome-wide expression profile pattern matching strategy. Methods We applied the ranked microarray pattern matching strategy Gene Set Enrichment Analysis to identify miRNA permutations with similar expression patterns to diseases. We also used quantitative reverse transcription PCR to validate the predicted expression levels of miRNAs in three diseases: inflammatory bowel disease (IBD), oesophageal cancer, and colorectal cancer. Results We found that hsa-miR-200 c was upregulated more than 40-fold in oesophageal cancer. The expression of miR-16 and miR-124 was not consistently upregulated in IBD or colorectal cancer. Conclusions Our results suggest that this expression profile matching strategy can be used to identify functional miRNA–disease relationships.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jianguo Huang ◽  
Mark Chen ◽  
Eric S. Xu ◽  
Lixia Luo ◽  
Yan Ma ◽  
...  

AbstractCooperating gene mutations are typically required to transform normal cells enabling growth in soft agar or in immunodeficient mice. For example, mutations in Kras and transformation-related protein 53 (Trp53) are known to transform a variety of mesenchymal and epithelial cells in vitro and in vivo. Identifying other genes that can cooperate with oncogenic Kras and substitute for Trp53 mutation has the potential to lead to new insights into mechanisms of carcinogenesis. Here, we applied a genome-wide CRISPR/Cas9 knockout screen in KrasG12D immortalized mouse embryonic fibroblasts (MEFs) to search for genes that when mutated cooperate with oncogenic Kras to induce transformation. We also tested if mutation of the identified candidate genes could cooperate with KrasG12D to generate primary sarcomas in mice. In addition to identifying the well-known tumor suppressor cyclin dependent kinase inhibitor 2A (Cdkn2a), whose alternative reading frame product p19 activates Trp53, we also identified other putative tumor suppressors, such as F-box/WD repeat-containing protein 7 (Fbxw7) and solute carrier family 9 member 3 (Slc9a3). Remarkably, the TCGA database indicates that both FBXW7 and SLC9A3 are commonly co-mutated with KRAS in human cancers. However, we found that only mutation of Trp53 or Cdkn2a, but not Fbxw7 or Slc9a3 can cooperate with KrasG12D to generate primary sarcomas in mice. These results show that mutations in oncogenic Kras and either Fbxw7 or Slc9a3 are sufficient for transformation in vitro, but not for in vivo sarcomagenesis.


2018 ◽  
Author(s):  
Carolien G.F. de Kovel ◽  
Clyde Francks

AbstractHand preference is a prominent behavioural trait linked to human brain asymmetry. A handful of genetic variants have been reported to associate with hand preference or quantitative measures related to it. Most of these reports were on the basis of limited sample sizes, by current standards for genetic analysis of complex traits. Here we performed a genome-wide association analysis of hand preference in the large, population-based UK Biobank cohort (N=331,037). We used gene-set enrichment analysis to investigate whether genes involved in visceral asymmetry are particularly relevant to hand preference, following one previous report. We found no evidence implicating any specific candidate variants previously reported. We also found no evidence that genes involved in visceral laterality play a role in hand preference. It remains possible that some of the previously reported genes or pathways are relevant to hand preference as assessed in other ways, or else are relevant within specific disorder populations. However, some or all of the earlier findings are likely to be false positives, and none of them appear relevant to hand preference as defined categorically in the general population. Within the UK Biobank itself, a significant association implicates the gene MAP2 in handedness.


2018 ◽  
Vol 217 (11) ◽  
pp. 3817-3828 ◽  
Author(s):  
Keigo Morita ◽  
Yutaro Hama ◽  
Tamaki Izume ◽  
Norito Tamura ◽  
Toshihide Ueno ◽  
...  

Macroautophagy is an intracellular degradation process that requires multiple autophagy-related (ATG) genes. In this study, we performed a genome-wide screen using the autophagic flux reporter GFP-LC3-RFP and identified TMEM41B as a novel ATG gene. TMEM41B is a multispanning membrane protein localized in the endoplasmic reticulum (ER). It has a conserved domain also found in vacuole membrane protein 1 (VMP1), another ER multispanning membrane protein essential for autophagy, yeast Tvp38, and the bacterial DedA family of putative half-transporters. Deletion of TMEM41B blocked the formation of autophagosomes at an early step, causing accumulation of ATG proteins and small vesicles but not elongating autophagosome-like structures. Furthermore, lipid droplets accumulated in TMEM41B-knockout (KO) cells. The phenotype of TMEM41B-KO cells resembled those of VMP1-KO cells. Indeed, TMEM41B and VMP1 formed a complex in vivo and in vitro, and overexpression of VMP1 restored autophagic flux in TMEM41B-KO cells. These results suggest that TMEM41B and VMP1 function together at an early step of autophagosome formation.


2018 ◽  
Author(s):  
Oliver H. Miller ◽  
Nils Grabole ◽  
Isabelle Wells ◽  
Benjamin J. Hall

AbstractLow-dose ketamine is an efficacious antidepressant for treatment-resistant unipolar and bipolar depressed patients. Major Depression Disorder patients receiving a single infusion report elevated mood within two hours, and ketamine’s antidepressant effects have been observed as long as seven days post-treatment. In light of this remarkable observation, efforts have been undertaken to “reverse-translate” ketamine’s effects to understand its mechanism of action. Major advances have been achieved in understanding the molecular, cellular, and circuit level changes that are initiated by low-dose ketamine. Although enhancement of protein synthesis clearly plays a role, the field lacks a comprehensive understanding of the protein synthesis program initiated after ketamine treatment. Here, using ribosome-bound mRNA footprinting and deep sequencing (RiboSeq), we uncover a genome-wide set of actively translated mRNAs (the translatome) in medial prefrontal cortex after an acute antidepressant-like dose of ketamine. Gene Ontology analysis confirmed that initiation of protein synthesis is a defining feature of antidepressant-dose ketamine in mice and Gene Set Enrichment Analysis points to a role for GPCR signaling, metabolism, vascularization, and structural plasticity in ketamine’s effects. One gene, VIPR2, whose protein product VPAC2 acts as a GPCR for the neuropeptide vasoactive intestinal peptide, was characterized in cortex and identified as a potential novel target for antidepressant action.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Carlos G. Sanchez ◽  
Christopher M. Acker ◽  
Audrey Gray ◽  
Malini Varadarajan ◽  
Cheng Song ◽  
...  

AbstractAggregates of hyperphosphorylated tau protein are a pathological hallmark of more than 20 distinct neurodegenerative diseases, including Alzheimer’s disease, progressive supranuclear palsy, and frontotemporal dementia. While the exact mechanism of tau aggregation is unknown, the accumulation of aggregates correlates with disease progression. Here we report a genome-wide CRISPR screen to identify modulators of endogenous tau protein for the first time. Primary screens performed in SH-SY5Y cells, identified positive and negative regulators of tau protein levels. Hit validation of the top 43 candidate genes was performed using Ngn2-induced human cortical excitatory neurons. Using this approach, genes and pathways involved in modulation of endogenous tau levels were identified, including chromatin modifying enzymes, neddylation and ubiquitin pathway members, and components of the mTOR pathway. TSC1, a critical component of the mTOR pathway, was further validated in vivo, demonstrating the relevance of this screening strategy. These findings may have implications for treating neurodegenerative diseases in the future.


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