Promoter CpG methylation of oestrogen receptors in leukaemia

2009 ◽  
Vol 29 (4) ◽  
pp. 211-216 ◽  
Author(s):  
Jie Yao ◽  
Qing Huang ◽  
Xiao-Bing Zhang ◽  
Wei-Ling Fu
Keyword(s):  
Cell Lines ◽  
Acute Leukaemia ◽  
Cpg Methylation ◽  
Dna Demethylation ◽  
Healthy Controls ◽  
Oestrogen Receptors ◽  
Leukaemia Cell ◽  
Direct Dna Sequencing ◽  
Reverse Transcription Pcr ◽  
Specific Pcr

Previous studies have suggested an important role of ERs (oestrogen receptors) in the pathogenesis of leukaemias. However, there is no information so far about the epigenetic characteristics of ERα isoforms and ERβ in leukaemias. In the present study, the mRNA expression and promoter CpG methylation of ERα isoforms (i.e. ERα-A, -B and -C) and ERβ in leukaemia cell lines were evaluated using RT–PCR (reverse transcription–PCR) and MSP (methylation-specific PCR) respectively. The methylation of ERs was further analysed in acute leukaemia patients by MSP and direct DNA sequencing. Although all ERα isoforms and ERβ were methylated in all leukaemia cell lines, except for ERα-C, which was unmethylated in HL-60 and K562 cell lines, only the expression of ERα-A was deficient in all cell lines and its expression could be reactivated by DNA demethylation reagents. With regard to the methylation characteristics in acute leukaemia patients, only ERα-A was inactivated and specifically methylated (95%; 38/40) in almost all patients and unmethylated in all healthy controls, whereas ERα-B, -C and ERβ were methylated in both patients and healthy controls. This result suggested that the methylated status of ERα-A might serve as an epigenetic biomarker of leukaemias. The present study is the first report that demonstrates selective inactivation of ERα isoforms through the promoter CpG methylation pathway in leukaemias.

Novel Stilbene-Based Antileukemic Agents Active in P-Glycoprotein Expressing and Apoptosis-Resistant Acute Leukaemia Cell Lines.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4436-4436
Author(s):  
Stefania Grimaudo ◽  
Antonietta Di Cristina ◽  
Vincenzo Abbadessa ◽  
Simoni Daniele ◽  
Marinella Roberti ◽  
...  
Keyword(s):  
Cell Lines ◽  
Anticancer Agents ◽  
Acute Leukaemia ◽  
Phenyl Ring ◽  
Malignant Tumors ◽  
Biologically Active ◽  
Monocytic Differentiation ◽  
Leukaemia Cell ◽  
P Glycoprotein ◽  
Induced Apoptosis

Abstract The stilbene scaffold is a basic element for a number of biologically active natural and synthetic compounds and in accordance with Evans’ definition it can be considered as a privileged structure. One of the most relevant and studied stilbenes is Resveratrol, a phytoalexin present in grapes, endowed with chemopreventive and chemotherapeutic properties and able to induce apoptosis in different cancer cell lines. Since reduced apoptosis has been implicated in the development and progression of malignant tumors and in the occurrence of chemoresistant phenotypes, resveratrol-induced apoptosis might therefore contribute to its antitumor activity. However, resveratrol is a not potent cytotoxic compound if compared with others chemotherapeutic drugs and it is scarcely active in P-glycoprotein expressing (MDR) and Bcr-Abl expressing leukaemia cells. With the aim to find new stilbene compounds active in resistant leukaemia cells we synthesized a small library of resveratrol analogs, bearing the 3,5-dimethoxy motif at the A phenyl ring and amino, methoxy and hydroxy moieties at the 3′-and/or 4′-positions. Moreover, we synthesized analogues which incorporate a phenyl ring as bioisosteric substitution of the alkenyl bridge. Among these new stilbenes we identified two compounds endowed with interesting antileukemic properties: a) a methoxylated cis derivative active at nanomolar concentrations in P-glycoprotein expressing HL60-R and CEM VBL100 acute leukaemia cell lines and in P-glycoprotein and Bcr-Abl expressing K562-ADR cell line which is resistant to apoptosis induced by most common anticancer agents, and b) a terphenyl derivative active in MDR and Bcr-Abl expressing cell lines. Both compounds induced apoptosis prevalently through the mitochondrial pathway. Differently from resveratrol and other stilbenes, the therphenyl derivative induced a block of cells in G0-G1 phase of cell cycle which was associated to the shift of the phosphorylation state of pRb from hyperphosphorylated to hypophosphorylated. Morover, low concentrations of this compound were able to induced a potent granulocytic and monocytic differentiation of HL60 cells.

SUV39H1-Mediated DNMT1 is Participated in the Epigenetic Regulation of Smad3 in Cervical Cancer

2020 ◽  
Vol 20 ◽  
Author(s):  
Li Zhang ◽  
Sijuan Tian ◽  
Minyi Zhao ◽  
Ting Yang ◽  
Shimin Quan ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Lines ◽  
Epigenetic Regulation ◽  
Promoter Region ◽  
Methylation Status ◽  
Regulation Mechanism ◽  
Methylation Specific Pcr ◽  
Specific Pcr ◽  
Immune Factor ◽  
Cancer Tissues

Background: Smad3 is a pivotal intracellular mediator for participating in the activation of multiple immune signal pathway. Objective: The epigenetic regulation mechanism of the positive immune factor Smad3 in cervical cancer remains unknown. Therefore, the epigenetic regulation on Smad3 is investigated in this study. Methods: The methylation status of SMAD3 was detected by Methylation-specific PCR (MS-PCR) and Quantitative Methylation-specific PCR (MS-qPCR) in cervical cancer tissues and cell lines. The underlying molecular mechanisms of SUV39H1-DNMT1-Smad3 regulation was elucidated using cervical cancer cell lines containing siRNA or/and overexpression system. Confirmation of the regulation of DNMT1 by SUV39H1 used Chromatin immunoprecipitation-qPCR (ChIP-qPCR). The statistical methods used for comparing samples between groups were paired t tests and one-way ANOVAs. Results: H3K9me3 protein which regulated by SUV39H1 directly interacts with the DNMT1 promoter region to regulate its expression in cervical cancer cells, resulting in the reduce expression of the downstream target gene DNMT1. In addition, DNMT1 mediates the epigenetic modulation of the SMAD3 gene by directly binding to its promoter region. The depletion of DNMT1 effectively restores the expression of Smad3 in vitro. Moreover, in an in vivo assay, the expression profile of SUV39H1-DNMT1 was found to correlate with Smad3 expression in accordance with the expression at the cellular level. Notably, the promoter region of SMAD3 was hypermethylated in cervical cancer tissues, and this hypermethylation inhibits the subsequent gene expression. Conclusion: These results indicate that SUV39H1-DNMT1 is a crucial Smad3 regulatory axis in cervical cancer. SUV39H1-DNMT1 axis may provide a potential therapeutic target for the treatment of cervical cancer.

scholarly journals Differential activation of the hprt gene on the inactive X chromosome in primary and transformed Chinese hamster cells.

1989 ◽  
Vol 9 (4) ◽  
pp. 1635-1641 ◽  
Author(s):  
S G Grant ◽  
R G Worton
Keyword(s):  
Cell Lines ◽  
X Chromosome ◽  
Gene Activation ◽  
Chinese Hamster ◽  
Fibroblast Cell ◽  
Dna Demethylation ◽  
Hprt Gene ◽  
Primary Fibroblast ◽  
Chinese Hamster Cells ◽  
Inactive X Chromosome

We have investigated the genetic activation of the hprt (hypoxanthine-guanine phosphoribosyltransferase) gene located on the inactive X chromosome in primary and transformed female diploid Chinese hamster cells after treatment with the DNA methylation inhibitor 5-azacytidine (5azaCR). Mutants deficient in HPRT were first selected by growth in 6-thioguanine from two primary fibroblast cell lines and from transformed lines derived from them. These HPRT- mutants were then treated with 5azaCR and plated in HAT (hypoxanthine-methotrexate-thymidine) medium to select for cells that had reexpressed the hprt gene on the inactive X chromosome. Contrary to previous results with primary human cells, 5azaCR was effective in activating the hprt gene in primary Chinese hamster fibroblasts at a low but reproducible frequency of 2 x 10(-6) to 7 x 10(-6). In comparison, the frequency in independently derived transformed lines varied from 1 x 10(-5) to 5 x 10(-3), consistently higher than in the nontransformed cells. This increase remained significant when the difference in growth rates between the primary and transformed lines was taken into account. Treatment with 5azaCR was also found to induce transformation in the primary cell lines but at a low frequency of 4 x 10(-7) to 8 x 10(-7), inconsistent with a two-step model of transformation followed by gene activation to explain the derepression of hprt in primary cells. Thus, these results indicate that upon transformation, the hprt gene on the inactive Chinese hamster X chromosome is rendered more susceptible to action by 5azaCR, consistent with a generalized DNA demethylation associated with the transformation event or with an increase in the instability of an underlying primary mechanism of X inactivation.

scholarly journals Yunnan orbivirus, a new orbivirus species isolated from Culex tritaeniorhynchus mosquitoes in China

2005 ◽  
Vol 86 (12) ◽  
pp. 3409-3417 ◽  
Author(s):  
Houssam Attoui ◽  
Fauziah Mohd Jaafar ◽  
Mourad Belhouchet ◽  
Nicolas Aldrovandi ◽  
Sanju Tao ◽  
...  
Keyword(s):  
Cell Lines ◽  
Neutralizing Antibodies ◽  
Yunnan Province ◽  
Coat Proteins ◽  
Outer Coat ◽  
Culex Tritaeniorhynchus ◽  
Specific Pcr ◽  
Mammalian Cell Lines ◽  
Mosquito Cell Lines ◽  
A New Species

An orbivirus designated Yunnan orbivirus (YUOV) was isolated from Culex tritaeniorhynchus mosquitoes collected in the Yunnan province of China. Electron microscopy showed particles with typical orbivirus morphology. The YUOV genome was sequenced completely and compared with previously characterized orbivirus genomes. Significant identity scores were detected between proteins encoded by the segments (Seg-1 to Seg-10) of YUOV and those encoded by their homologues in insect-borne and tick-borne orbiviruses. Analysis of VP1 (Pol) and VP2 (T2, which correlates with the virus serogroup) indicated that YUOV is a new species of the genus Orbivirus that is unrelated to the other insect-borne orbiviruses. The replication of YUOV in mosquito cell lines was restricted to Aedes albopictus cells and the virus failed to replicate in mammalian cell lines. However, intraperitoneal injection of virus into naïve mice resulted in productive, non-lethal virus replication and viraemia. Infected mice developed serum neutralizing antibodies and were protected against a new infection challenge. Sequence analysis of clones from the segments encoding outer coat proteins (Seg-3 and Seg-6) of YUOV recovered from mouse blood did not show significant changes in the sequences. The availability of the complete genome sequence will facilitate the development of sequence-specific PCR assays for the study of YUOV epidemiology in the field.

Aquaporins can facilitate Nox-produced hydrogen peroxide transport through plasma membrane in leukaemia cell lines

2012 ◽  
Vol 53 ◽  
pp. S158-S159
Author(s):  
F. Vieceli Dalla Sega⁎ ◽  
L. Zambonin ◽  
D. Fiorentini ◽  
B. Rizzo ◽  
L. Landi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Plasma Membrane ◽  
Cell Lines ◽  
Leukaemia Cell

scholarly journals Promoter Methylation of RASSF1A Associates to Adult Secondary Glioblastomas and Pediatric Glioblastomas

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jorge Muñoz ◽  
María del Mar Inda ◽  
Paula Lázcoz ◽  
Idoya Zazpe ◽  
Xing Fan ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Cell Lines ◽  
Tumor Suppressor Genes ◽  
Promoter Hypermethylation ◽  
Suppressor Genes ◽  
Primary Tumors ◽  
Specific Pcr ◽  
Inactivation Mechanism ◽  
Altered Gene ◽  
Homozygous Deletions

While allelic losses and mutations of tumor suppressor genes implicated in the etiology of astrocytoma have been widely assessed, the role of epigenetics is still a matter of study. We analyzed the frequency of promoter hypermethylation by methylation-specific PCR (MSP) in five tumor suppressor genes (PTEN, MGMT, RASSF1A, p14ARF, and p16INK4A), in astrocytoma samples and cell lines. RASSF1A was the most frequently hypermethylated gene in all grades of astrocytoma samples, in cell lines, and in adult secondary GBM. It was followed by MGMT. PTEN showed a slight methylation signal in only one GBM and one pilocytic astrocytoma, and in two cell lines; while p14ARF and p16INK4A did not show any evidence of methylation in primary tumors or cell lines. In pediatric GBM, RASSF1A was again the most frequently altered gene, followed by MGMT; PTEN, p14 and p16 showed no alterations. Lack or reduced expression of RASSF1A in cell lines was correlated with the presence of methylation. RASSF1A promoter hypermethylation might be used as a diagnostic marker for secondary GBM and pediatric GBM. Promoter hypermethylation might not be an important inactivation mechanism in other genes like PTEN, p14ARF and p16INK4A, in which other alterations (mutations, homozygous deletions) are prevalent.

scholarly journals The Case for GNMT as a Biomarker and a Therapeutic Target in Pancreatic Cancer

2021 ◽  
Vol 14 (3) ◽  
pp. 209
Author(s):  
Zachary Heinzman ◽  
Connor Schmidt ◽  
Marek K. Sliwinski ◽  
Nalin C. W. Goonesekere
Keyword(s):  
Pancreatic Cancer ◽  
Cell Lines ◽  
Therapeutic Target ◽  
Early Stage ◽  
Dependent Manner ◽  
Strong Inhibitor ◽  
Tissue Samples ◽  
Reverse Transcription Pcr ◽  
Tumor Stages ◽  
Early Tumor

The high mortality rate for pancreatic cancer (PC) is due to the lack of specific symptoms at early tumor stages and a high biological aggressiveness. Reliable biomarkers and new therapeutic targets would help to improve outlook in PC. In this study, we analyzed the expression of GNMT in a panel of pancreatic cancer cell lines and in early-stage paired patient tissue samples (normal and diseased) by quantitative reverse transcription-PCR (qRT-PCR). We also investigated the effect of 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranoside (PGG) as a therapeutic agent for PC. We find that GNMT is markedly downregulated (p < 0.05), in a majority of PC cell lines. Similar results are observed in early-stage patient tissue samples, where GNMT expression can be reduced by a 100-fold or more. We also show that PGG is a strong inhibitor of PC cell proliferation, with an IC50 value of 12 ng/mL, and PGG upregulates GNMT expression in a dose-dependent manner. In conclusion, our data show that GNMT has promise as a biomarker and as a therapeutic target for PC.

scholarly journals IFT80 Improves Invasion Ability in Gastric Cancer Cell Line via ift80/p75NGFR/MMP9 Signaling

2018 ◽  
Vol 19 (11) ◽  
pp. 3616 ◽  
Author(s):  
Rui Wang ◽  
Xiaoyan Deng ◽  
Chengfu Yuan ◽  
Hongmei Xin ◽  
Geli Liu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Reverse Transcription ◽  
Gastric Cancer Cell ◽  
Gastric Cancer Cells ◽  
Quantitative Reverse Transcription Pcr ◽  
Reverse Transcription Pcr ◽  
Gastric Cancer Cell Lines

The assembly and maintenance of cilia depend on intraflagellar transport (IFT) proteins, which play an important role in development and homeostasis. IFT80 is a newly defined IFT protein and partial mutation of IFT80 in humans causes diseases such as Jeune asphyxiating thoracic dystrophy (JATD) and short rib polydactyly (SRP) type III, both characterized by abnormal skeletal development. However, the role and mechanism of IFT80 in the invasion of gastric cancer is unknown. We established SGC-7901 and MKN-45 gastric cancer cell lines that stably overexpressed IFT80, as verified by quantitative reverse transcription-PCR, Western blot, and immunofluorescence. Matrix metalloproteinase-9 (MMP9) plays an important role in tumor invasion, and its expression was assessed by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence. The invasion ability of IFT80 on SGC-7901 and MKN-45 cells was examined by the Matrigel invasion assay. The relationship between p75NGFR, and the p75NGFR antagonists, PD90780 and IFT80, were detected by quantitative reverse transcription-PCR and Western blotting. We first detected an IFT80 expression pattern, and found that IFT80 was highly expressed in gastric cancer clinical samples. Overexpression of IFT80 in the gastric cancer cell lines, SGC-7901 and MKN-45, led to lengthening cilia. Additionally, overexpression of IFT80 significantly improved proliferation and invasion, but inhibited apoptosis, in gastric cancer cells. We further found that overexpression of IFT80 increased p75NGFR and MMP9 mRNA and protein expression. Treatment with the p75NGFR antagonist PD90780 inhibited the increased invasion ability resulting from overexpression of IFT80 in SGC-7901 and MKN-45 gastric cancer cells. Thus, these results suggest that IFT80 plays an important role in invasion of gastric cancer through regulating the ift80/p75NGFR/MMP9 signal pathways.

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