scholarly journals Decitabine treatment demethylates vast majority of high-confidence differentially methylated regions in HCT-116 colorectal cancer cells

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 886
Author(s):  
Anna Sandler ◽  
Jonathan Anderson ◽  
Ariane Balaram ◽  
Yoan Ganev ◽  
Samuel Gascoigne ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cpg Island ◽  
Promoter Hypermethylation ◽  
Clonogenic Survival ◽  
Causal Link ◽  
Cancer Drug ◽  
Transcriptional Enhancer ◽  
Differentially Methylated Regions ◽  
High Confidence ◽  
Hct 116

Background: Gene silencing by CpG island hypermethylation often plays a role in colorectal cancer (CRC) progression. Certain regions of the genome, called high confidence differentially-methylated regions (DMRs), are consistently hypermethylated across numerous patient samples. Methods: In this study, we used bioinformatics and bisulfite PCR sequencing of HCT-116 cells to investigate methylation levels at DMRs in the promoters of six genes: DKK3, EN1, MiR34b, SDC2, SPG20, and TLX1. We then investigated whether the anti-cancer drug decitabine, had a demethylating effect at these promoter regions. Results: We found that hypermethylation correlated with lack of transcriptional enhancer binding in these six regions. Importantly, we observed that for all DMRs, decitabine significantly reduced CpG methylation. Decitabine also reduced clonogenic survival, suggesting that there is a correlation between lower CpG island methylation levels and reduced cancerous properties. Conclusions: Our study provided single-nucleotide resolution and revealed hypermethylated CpG sites not shown by previous genome-wide methylation studies. In the future, we plan to perform experiments that demonstrate a causal link between promoter hypermethylation and carcinogenesis and that more accurately model treatments in CRC patients.

Bioactive Peptides Sensitize Cells to Anticancer Effects of Oxaliplatin in Human Colorectal Cancer Xenografts in Nude Mice

2019 ◽  
Vol 26 (7) ◽  
pp. 512-522
Author(s):  
Xian Li ◽  
Long Xia ◽  
Xiaohui Ouyang ◽  
Qimuge Suyila ◽  
Liya Su ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Colorectal Cancer ◽  
Nude Mice ◽  
Low Dose ◽  
Bioactive Peptides ◽  
Human Colorectal Cancer ◽  
Short Term ◽  
Hct 116

<P>Background: Despite new agent development and short-term benefits in patients with Colorectal Cancer (CRC), metastatic CRC cure rates have not improved due to high rates of oxaliplatin resistance and toxicity. There is an urgent need for effective tools to prevent and treat CRC and reduce morbidity and mortality of CRC patients. Exploring the effects of bioactive peptides on the antitumor to CRC was of vital importance to the clinical application. </P><P> Objective: This study aimed to investigate the therapeutic impact of Anticancer Bioactive Peptides (ACBP) on anticancer effect of oxaliplatin (LOHP) in human colorectal cancer xenografts models in nude mice. </P><P> Methods: HCT-116 cells were cultured in vitro via CCK-8 assays and the absorbance was measured at 450 nm. Apoptosis and cell cycle were assessed by Flow Cytometry (FCM) in vitro. HCT-116 human colorectal cancer cells inoculated subcutaneously in nude mice of treatment with PBS (GG), ACBP, LOHP, ACBP+LOHP (A+L) in vivo. The quality of life was assessed by dietary amount of nude mice, the weight of nude mice, inhibition rates, tumor weight and tumor volume. Immunohistochemistry and RT-qPCR method was conducted to determine the levels of apoptosisregulating proteins/genes in transplanted tumors. </P><P> Results: ACBP induced substantial reductions in viable cell numbers and apoptosis of HCT116 cells in combined with LOHP in vitro. Compared with the control GG group, ACBP combined low dose oxaliplatin (U) group demonstrated significantly different tumor volume, the rate of apoptosis, the expression levels of Cyt-C, caspase-3,8,9 proteins and corresponding RNAs (P<0.05). The expression of pro-apoptotic proteins in the cytoplasm around the nucleus was significantly enhanced by ACBP. Short term intermittent use of ACBP alone indicted a certain inhibitory effect on tumor growth, and improve the quality of life of tumor bearing nude mice. </P><P> Conclusion: ACBP significantly increased the anti-cancer responses of low dose oxaliplatin (L-LOHP), thus, significantly improving the quality of life of tumor-bearing nude mice.</P>

scholarly journals The Role of the CpG Island Methylator Phenotype in Colorectal Cancer Prognosis Depends on Microsatellite Instability Screening Status

2010 ◽  
Vol 16 (6) ◽  
pp. 1845-1855 ◽  
Author(s):  
Anna M. Dahlin ◽  
Richard Palmqvist ◽  
Maria L. Henriksson ◽  
Maria Jacobsson ◽  
Vincy Eklöf ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Cpg Island ◽  
Cancer Prognosis ◽  
Cpg Island Methylator Phenotype ◽  
Methylator Phenotype

scholarly journals Hemistepsin A suppresses colorectal cancer growth through inhibiting pyruvate dehydrogenase kinase activity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ling Jin ◽  
Eun-Yeong Kim ◽  
Tae-Wook Chung ◽  
Chang Woo Han ◽  
So Young Park ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Pyruvate Dehydrogenase ◽  
Cancer Metabolism ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Pyruvate Dehydrogenase Kinase ◽  
Cancer Drug ◽  
Potential Candidate ◽  
Mitochondrial Ros

AbstractMost cancer cells primarily produce their energy through a high rate of glycolysis followed by lactic acid fermentation even in the presence of abundant oxygen. Pyruvate dehydrogenase kinase (PDK) 1, an enzyme responsible for aerobic glycolysis via phosphorylating and inactivating pyruvate dehydrogenase (PDH) complex, is commonly overexpressed in tumors and recognized as a therapeutic target in colorectal cancer. Hemistepsin A (HsA) is a sesquiterpene lactone isolated from Hemistepta lyrata Bunge (Compositae). Here, we report that HsA is a PDK1 inhibitor can reduce the growth of colorectal cancer and consequent activation of mitochondrial ROS-dependent apoptotic pathway both in vivo and in vitro. Computational simulation and biochemical assays showed that HsA directly binds to the lipoamide-binding site of PDK1, and subsequently inhibits the interaction of PDK1 with the E2 subunit of PDH complex. As a result of PDK1 inhibition, lactate production was decreased, but oxygen consumption was increased. Mitochondrial ROS levels and mitochondrial damage were also increased. Consistent with these observations, the apoptosis of colorectal cancer cells was promoted by HsA with enhanced activation of caspase-3 and -9. These results suggested that HsA might be a potential candidate for developing a novel anti-cancer drug through suppressing cancer metabolism.

scholarly journals Abnormal promoter DNA hypermethylation of the integrin, nidogen, and dystroglycan genes in breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vladimir V. Strelnikov ◽  
Ekaterina B. Kuznetsova ◽  
Alexander S. Tanas ◽  
Viktoria V. Rudenko ◽  
Alexey I. Kalinkin ◽  
...  
Keyword(s):  
Cpg Island ◽  
Strong Association ◽  
Cell Activity ◽  
Promoter Hypermethylation ◽  
Normal Breast ◽  
Breast Carcinomas ◽  
Her2 Positive ◽  
A Genome ◽  
Extracellular Matrix Components ◽  
Integrin Α4

AbstractCell transmembrane receptors and extracellular matrix components play a pivotal role in regulating cell activity and providing for the concerted integration of cells in the tissue structures. We have assessed DNA methylation in the promoter regions of eight integrin genes, two nidogen genes, and the dystroglycan gene in normal breast tissues and breast carcinomas (BC). The protein products of these genes interact with the basement membrane proteins LAMA1, LAMA2, and LAMB1; abnormal hypermethylation of the LAMA1, LAMA2, and LAMB1 promoters in BC has been described in our previous publications. In the present study, the frequencies of abnormal promoter hypermethylation in BC were 13% for ITGA1, 31% for ITGA4, 4% for ITGA7, 39% for ITGA9, 38% for NID1, and 41% for NID2. ITGA2, ITGA3, ITGA6, ITGB1, and DAG1 promoters were nonmethylated in normal and BC samples. ITGA4, ITGA9, and NID1 promoter hypermethylation was associated with the HER2 positive tumors, and promoter hypermethylation of ITGA1, ITGA9, NID1 and NID2 was associated with a genome-wide CpG island hypermethylated BC subtype. Given that ITGA4 is not expressed in normal breast, one might suggest that its abnormal promoter hypermethylation in cancer is non-functional and is thus merely a passenger epimutation. Yet, this assumption is not supported by our finding that it is not associated with a hypermethylated BC subtype. ITGA4 acquires expression in a subset of breast carcinomas, and methylation of its promoter may be preventive against expression in some tumors. Strong association of abnormal ITGA4 hypermethylation with the HER2 positive tumors (p = 0.0025) suggests that simultaneous presence of both HER2 and integrin α4 receptors is not beneficial for tumor cells. This may imply HER2 and integrin α4 signaling pathways interactions that are yet to be discovered.

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