scholarly journals TET-catalyzed 5-hydroxymethylcytosine regulates gene expression in differentiating colonocytes and colon cancer

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Christopher G. Chapman ◽  
Christopher J. Mariani ◽  
Feng Wu ◽  
Katherine Meckel ◽  
Fatma Butun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colon Cancer ◽  
Regulation Of Gene Expression ◽  
Human Colon ◽  
Cell Types ◽  
Enzymatic Oxidation ◽  
Dna Hydroxymethylation ◽  
Differentiated Cells ◽  
Colon Cancers

Abstract The formation of differentiated cell types from pluripotent progenitors involves epigenetic regulation of gene expression. DNA hydroxymethylation results from the enzymatic oxidation of 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) 5-mC dioxygenase enzymes. Previous work has mapped changes in 5-mC during differentiation of intestinal stem cells. However, whether or not 5-hmC regulates colonocyte differentiation is unknown. Here we show that 5-hmC regulates gene expression during colonocyte differentiation and controls gene expression in human colon cancers. Genome-wide profiling of 5-hmC during in vitro colonic differentiation demonstrated that 5-hmC is gained at highly expressed and induced genes and is associated with intestinal transcription factor binding sites, including those for HNF4A and CDX2. TET1 induction occurred during differentiation and TET1 knockdown altered gene expression and inhibited barrier formation of colonocytes. We find that the 5-hmC distribution in primary human colonocytes parallels the distribution found in differentiated cells in vitro and that gene-specific 5-hmC changes in human colon cancers are directly correlated with changes in gene expression. Our results support a model in which 5-hmC regulates differentiation of adult human intestine and 5-hmC alterations contribute to the disrupted gene expression in colon cancer.

scholarly journals Lemongrass Extract Possesses Potent Anticancer Activity Against Human Colon Cancers, Inhibits Tumorigenesis, Enhances Efficacy of FOLFOX, and Reduces Its Adverse Effects

2019 ◽  
Vol 18 ◽  
pp. 153473541988915 ◽  
Author(s):  
Ivan Ruvinov ◽  
Christopher Nguyen ◽  
Benjamin Scaria ◽  
Caleb Vegh ◽  
Ola Zaitoon ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Anticancer Activity ◽  
Cancer Cells ◽  
Human Colon ◽  
Dependent Manner ◽  
Anticancer Efficacy ◽  
Colon Cancers ◽  
Induced Apoptosis

Current chemotherapeutics for metastatic colorectal cancers have limited success and are extremely toxic due to nonselective targeting. Some natural extracts have been traditionally taken and have shown anticancer activity. These extracts have multiple phytochemicals that can target different pathways selectively in cancer cells. We have shown previously that lemongrass ( Cymbopogon citratus) extract is effective at inducing cell death in human lymphomas. However, the efficacy of lemongrass extract on human colorectal cancer has not been investigated. Furthermore, its interactions with current chemotherapies for colon cancer is unknown. In this article, we report the anticancer effects of ethanolic lemongrass extract in colorectal cancer models, and importantly, its interactions with FOLFOX and Taxol. Lemongrass extract induced apoptosis in colon cancer cells in a time and dose-dependent manner without harming healthy cells in vitro. Oral administration of lemongrass extract was well tolerated and effective at inhibiting colon cancer xenograft growth in mice. It enhanced the anticancer efficacy of FOLFOX and, interestingly, inhibited FOLFOX-related weight loss in animals given the combination treatment. Furthermore, feeding lemongrass extract to APCmin/+ transgenic mice led to the reduction of intestinal tumors, indicating its preventative potential. Therefore, this natural extract has potential to be developed as a supplemental treatment for colorectal cancer.

scholarly journals Engineering improved Cas13 effectors for targeted post-transcriptional regulation of gene expression

2021 ◽  
Author(s):  
Emeric J Charles ◽  
Shin Eui Kim ◽  
Gavin J Knott ◽  
Dylan Smock ◽  
Jennifer Doudna ◽  
...  
Keyword(s):  
Gene Expression ◽  
Directed Evolution ◽  
Regulation Of Gene Expression ◽  
Exon Skipping ◽  
Cell Types ◽  
Human Cells ◽  
Translational Repression ◽  
E Coli ◽  
Rna Targeting

Cas13 is a family of unique RNA-targeting CRISPR-Cas effectors, making it an appealing tool for probing and perturbing RNA function. However only a few Cas13 homologs have been shown to mediate robust RNA targeting in human cells, suggesting that unknown elements may be limiting their efficacy. Furthermore, many Cas13 enzymes show high degrees of toxicity upon targeting and have not been shown to mediate specific knockdown in other cell types such as E. coli. Here, we show that catalytically inactive Cas13 enzymes can be repurposed for efficient translational repression in bacteria with no associated growth defects. To achieve this advance, we carried out a directed evolution screen to engineer functional Cas13a variants, and identified a number of stabilizing mutations, which enabled efficient post transcriptional knockdown of gene expression. In vitro characterization of the resulting engineered Lbu Cas13a mutant, termed eLbu, revealed both stabilization and altered cleavage kinetics. Finally, we show that eLbu can be used for efficient exon skipping in human cells. This work represents the first demonstration of targeted translational repression in E. coli using a CRISPR enzyme, as well as the first directed evolution of a Cas13a enzyme. Such a platform could allow for engineering other aspects of this protein family to obtain more robust RNA targeting tools.

scholarly journals PSIV-5 Developmental and hormonal regulation of gene expression of fibrillin-1 (FBN1) and the asprosin receptor, olfactory receptor family 4 subfamily M member 1 (OR4M1), in bovine ovarian cells

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 283-284
Author(s):  
Excel Rio Maylem ◽  
Leon Spicer ◽  
Isadora Batalha ◽  
Luis Schutz
Keyword(s):  
Gene Expression ◽  
Hormonal Regulation ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
Mrna Abundance ◽  
Hormone Regulation ◽  
Polycystic Ovaries ◽  
Fbn1 Gene ◽  
Fibrillin 1

Abstract Asprosin is a novel fasting-induced protein associated with insulin resistance and polycystic ovaries in humans. It is encoded by FBN1 gene and produced when FBN1 is cleaved by the enzyme furin. In cattle, the role of asprosin is unknown. To characterize mRNA abundance of FBN1, furin, and the asprosin receptor, OR4M1, in granulosa (GC) and theca cells (TC), and identify hormones regulating FBN1 mRNA expression, GC and TC from small (< 6 mm; SM) and large (>5 mm; LG) follicles were collected from heifers at an abattoir and used for real-time gene expression analysis or in vitro evaluation of hormone regulation. SMTC had 151-fold greater (P < 0.05) FBN1 mRNA abundance than SMGC, and LGTC had 50-fold greater (P < 0.05) FBN1 mRNA than LGGC. In contrast, OR4M1 mRNA abundance was significantly greater (by 81-fold) in SMGC than LGGC and did not differ from SMTC, but LGTC had 9-fold greater (P < 0.05) OR4M1 mRNA abundance than LGGC. Furin mRNA was significantly greater (by 2.6-fold) in SMGC than SMTC but did not differ between LGTC and LGGC. In SMGC, leptin, insulin, GH, FSH, EGF, and steroids had no effect (P >0.10) on FBN1 mRNA abundance. In contrast, TGFB1, WNT3A and FGF9 increased (P < 0.05) and IGF1 significantly decreased SMGC FBN1 mRNA abundance. In LGTC, leptin, insulin, LH, IGF1 and steroids did not significantly affect FBN1 mRNA, but TGFB1, WNT3A, EGF, FGF2 and FGF9 increased (P< 0.05) FBN1 mRNA abundance. Altogether, FBN1 mRNA was more highly expressed in TC than GC and was stimulated by TGFB1, WNT3A and FGF9 in both cell types. Developmental and hormonal regulation of FBN1, furin and OR4M1 along with a greater expression of OR4M1 mRNA in GC than TC suggests that asprosin may be acting as a paracrine regulator of ovarian follicular function in cattle.

Control of Transcription of tRNA Genes

1981 ◽  
Vol 39 ◽  
pp. 480-481
Author(s):  
K.U. Sprague ◽  
D. Morton ◽  
D. Larson
Keyword(s):  
Gene Expression ◽  
Bombyx Mori ◽  
Genomic Dna ◽  
Molecular Mechanisms ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
The Other ◽  
Trna Genes ◽  
Trna Species

Our laboratory is interested in the regulation of gene expression during eukaryotic development. Among the genes we are currently studying are those coding for alanine tRNA in the silkworm, Bombyx mori. These genes are particularly interesting because one Bombyx alanine tRNA species is constitutive -- that is, it is found in a variety of cell types -- while the other major alanine tRNA appears only in the silkgland. The silkgland-specific tRNA predominates when the highly specialized cells of this tissue are synthesizing large amounts of the alanine-rich silk protein, fibroin. The nucleotide sequences of the two alanine tRNAs indicates that they are encoded by different genes.Our goal is to understand the molecular mechanisms governing the differential expression of Bombyx tRNAAla genes. Our approach is to isolate the genes with molecular cloning techniques, and to transcribe and process them in vitro. We have cloned 14 different genomic DNA fragments containing tRNAAla genes, and have developed faithful transcription systems from several different Bombyx tissues, including silkgland.

scholarly journals P-0193 Transgelin Promotes The Invasiveness of Human Colon Cancer Cells in Vitro

2012 ◽  
Vol 23 ◽  
pp. iv85-iv86
Author(s):  
Ying Lin ◽  
Yuan-yuan Fang ◽  
Hong Su ◽  
Zhou Hui-Min ◽  
Qi-Kui Chen
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Human Colon ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Human Colon Cancer Cells

In vitro antiproliferative activity against human colon cancer cell lines of representative 4-thiazolidinones. Part I

2005 ◽  
Vol 15 (17) ◽  
pp. 3930-3933 ◽  
Author(s):  
Rosaria Ottanà ◽  
Stefania Carotti ◽  
Rosanna Maccari ◽  
Ida Landini ◽  
Giuseppa Chiricosta ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Antiproliferative Activity ◽  
Human Colon ◽  
Colon Cancer Cell ◽  
Human Colon Cancer Cell ◽  
Human Colon Cancer ◽  
Colon Cancer Cell Lines

scholarly journals Fos and jun cooperate in transcriptional regulation via heterologous activation domains.

1990 ◽  
Vol 10 (10) ◽  
pp. 5532-5535 ◽  
Author(s):  
C Abate ◽  
D Luk ◽  
E Gagne ◽  
R G Roeder ◽  
T Curran
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Regulation Of Gene Expression ◽  
Negative Influence ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Transcriptional Stimulation

The products of c-fos and c-jun (Fos and Jun) function in gene regulation by interacting with the AP-1 binding site. Here we have examined the contribution of Fos and Jun toward transcriptional activity by using Fos and Jun polypeptides purified from Escherichia coli. Fos contained a transcriptional activation domain as well as a region which exerted a negative influence on transcriptional activity in vitro. Moreover, distinct activation domains in both Fos and Jun functioned cooperatively in transcriptional stimulation. Thus, regulation of gene expression by Fos and Jun results from an integration of several functional domains in a bimolecular complex.

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