scholarly journals Genome-scale CRISPR-Cas9 screen of Wnt/β-catenin signaling identifies therapeutic targets for colorectal cancer

2021 ◽  
Vol 7 (21) ◽  
pp. eabf2567
Author(s):  
Chunhua Wan ◽  
Sylvia Mahara ◽  
Claire Sun ◽  
Anh Doan ◽  
Hui Kheng Chua ◽  
...  

Aberrant activation of Wnt/β-catenin pathway is a key driver of colorectal cancer (CRC) growth and of great therapeutic importance. In this study, we performed comprehensive CRISPR screens to interrogate the regulatory network of Wnt/β-catenin signaling in CRC cells. We found marked discrepancies between the artificial TOP reporter activity and β-catenin–mediated endogenous transcription and redundant roles of T cell factor/lymphoid enhancer factor transcription factors in transducing β-catenin signaling. Compiled functional genomic screens and network analysis revealed unique epigenetic regulators of β-catenin transcriptional output, including the histone lysine methyltransferase 2A oncoprotein (KMT2A/Mll1). Using an integrative epigenomic and transcriptional profiling approach, we show that KMT2A loss diminishes the binding of β-catenin to consensus DNA motifs and the transcription of β-catenin targets in CRC. These results suggest that KMT2A may be a promising target for CRCs and highlight the broader potential for exploiting epigenetic modulation as a therapeutic strategy for β-catenin–driven malignancies.

Metabolites ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 456
Author(s):  
Pejman Salahshouri ◽  
Modjtaba Emadi-Baygi ◽  
Mahdi Jalili ◽  
Faiz M. Khan ◽  
Olaf Wolkenhauer ◽  
...  

The human gut microbiota plays a dual key role in maintaining human health or inducing disorders, for example, obesity, type 2 diabetes, and cancers such as colorectal cancer (CRC). High-throughput data analysis, such as metagenomics and metabolomics, have shown the diverse effects of alterations in dynamic bacterial populations on the initiation and progression of colorectal cancer. However, it is well established that microbiome and human cells constantly influence each other, so it is not appropriate to study them independently. Genome-scale metabolic modeling is a well-established mathematical framework that describes the dynamic behavior of these two axes at the system level. In this study, we created community microbiome models of three conditions during colorectal cancer progression, including carcinoma, adenoma and health status, and showed how changes in the microbial population influence intestinal secretions. Conclusively, our findings showed that alterations in the gut microbiome might provoke mutations and transform adenomas into carcinomas. These alterations include the secretion of mutagenic metabolites such as H2S, NO compounds, spermidine and TMA, as well as the reduction of butyrate. Furthermore, we found that the colorectal cancer microbiome can promote inflammation, cancer progression (e.g., angiogenesis) and cancer prevention (e.g., apoptosis) by increasing and decreasing certain metabolites such as histamine, glutamine and pyruvate. Thus, modulating the gut microbiome could be a promising strategy for the prevention and treatment of CRC.


2013 ◽  
Vol 56 (21) ◽  
pp. 8616-8625 ◽  
Author(s):  
Fanny L. Cherblanc ◽  
Kathryn L. Chapman ◽  
Jim Reid ◽  
Aaron J. Borg ◽  
Sandeep Sundriyal ◽  
...  

2004 ◽  
Vol 24 (12) ◽  
pp. 5184-5196 ◽  
Author(s):  
Anders Lade Nielsen ◽  
Poul Jørgensen ◽  
Thierry Lerouge ◽  
Margarita Cerviño ◽  
Pierre Chambon ◽  
...  

ABSTRACT Haploinsufficiency of the NSD1 gene is a hallmark of Sotos syndrome, and rearrangements of this gene by translocation can cause acute myeloid leukemia. The NSD1 gene product is a SET-domain histone lysine methyltransferase that has previously been shown to interact with nuclear receptors. We describe here a novel NSD1-interacting protein, Nizp1, that contains a SCAN box, a KRAB-A domain, and four consensus C2H2-type zinc fingers preceded by a unique finger derivative, referred to herein as the C2HR motif. The C2HR motif functions to mediate protein-protein interaction with the cysteine-rich (C5HCH) domain of NSD1 in a Zn(II)-dependent fashion, and when tethered to RNA polymerase II promoters, represses transcription in an NSD1-dependent manner. Mutations of the cysteine or histidine residues in the C2HR motif abolish the interaction of Nizp1 with NSD1 and compromise the ability of Nizp1 to repress transcription. Interestingly, converting the C2HR motif into a canonical C2H2 zinc finger has a similar effect. Thus, Nizp1 contains a novel type of zinc finger motif that functions as a docking site for NSD1 and is more than just a degenerate evolutionary remnant of a C2H2 motif.


2016 ◽  
Vol 10 (1) ◽  
pp. 114-131 ◽  
Author(s):  
Tao Huang ◽  
Chengyuan Lin ◽  
Linda L. D. Zhong ◽  
Ling Zhao ◽  
Ge Zhang ◽  
...  

As a leading cause of cancer deaths worldwide, colorectal cancer (CRC) results from accumulation of both genetic and epigenetic alterations. Disruption of epigenetic regulation in CRC, particularly aberrant histone methylation mediated by histone methyltransferases (HMTs) and demethylases (HDMs), have drawn increasing interest in recent years. In this paper, we aim to review the roles of histone methylation and associated enzymes in the pathogenesis of CRC, and the development of small-molecule modulators to regulate histone methylation for treating CRC. Multiple levels of evidence suggest that aberrant histone methylations play important roles in CRC. More than 20 histone-methylation enzymes are found to be clinically relevant to CRC, including 17 oncoproteins and 8 tumor suppressors. Inhibitors of EZH2 and DOT1L have demonstrated promising therapeutic effects in preclinical CRC treatment. Potent and selective chemical probes of histone-methylation enzymes are required for validation of their functional roles in carcinogenesis and clinical translations as CRC therapies. With EZH2 inhibitor EPZ-6438 entering into phase I/II trials for advanced solid tumors, histone methylation is emerging as a promising target for CRC.


Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 42
Author(s):  
Omeima Abdullah ◽  
Mahmoud Alhosin

HAUSP (herpes virus-associated ubiquitin-specific protease), also known as Ubiquitin Specific Protease 7, plays critical roles in cellular processes, such as chromatin biology and epigenetics, through the regulation of different signaling pathways. HAUSP is a main partner of the “Epigenetic Code Replication Machinery,” ECREM, a large protein complex that includes several epigenetic players, such as the ubiquitin-like containing plant homeodomain (PHD) and an interesting new gene (RING), finger domains 1 (UHRF1), as well as DNA methyltransferase 1 (DNMT1), histone deacetylase 1 (HDAC1), histone methyltransferase G9a, and histone acetyltransferase TIP60. Due to its deubiquitinase activity and its ability to team up through direct interactions with several epigenetic regulators, mainly UHRF1, DNMT1, TIP60, the histone lysine methyltransferase EZH2, and the lysine-specific histone demethylase LSD1, HAUSP positions itself at the top of the regulatory hierarchies involved in epigenetic silencing of tumor suppressor genes in cancer. This review highlights the increasing role of HAUSP as an epigenetic master regulator that governs a set of epigenetic players involved in both the maintenance of DNA methylation and histone post-translational modifications.


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