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Query: UNIPROT:P43146 (
tumour suppressor
)
5,935
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Methylation of CpG islands (CGIs) in the promoter regions of
tumour suppressor
genes is common in colorectal cancer and occurs also in an age-dependent manner in the morphologically normal colorectal mucosa. In this study, we quantified the level of methylation of six genes associated with the Wnt signalling pathway (adenomatous polyposis coli, DKK1,
WIF1
, SFRP1, SFRP2 and SFRP5) together with long-interspersed nuclear element-1 as a surrogate for global methylation. DNA methylation was analysed in 260 individual colorectal crypts obtained from eight female patients with no evidence of colorectal disease and five with colorectal cancer. Significant variation in methylation levels for each of the six genes existed between crypts from the same biopsy. The variation in both global and gene-specific CGI methylation between crypts from the same individual was significantly less than that between individuals. Bisulphite sequencing provided insight into the mechanism of aberrant methylation showing that CGI methylation occurs in an 'all-or-none' manner by the directional spreading of methylation from further upstream. Univariate statistical analyses revealed that there were significant differences in crypt-specific methylation associated with both aging and disease status. A multivariate statistical modelling approach was able to distinguish both subject age and health status based on crypt-specific methylation profiles. Our results indicate that the differential methylation of genes associated with the Wnt signalling pathway affecting individual morphologically normal crypts may contribute to the age-dependent generation of the colonic field defect and, in combination with mutations, to the stepwise development of colorectal neoplasia.
...
PMID:Patterns of DNA methylation in individual colonic crypts reveal aging and cancer-related field defects in the morphologically normal mucosa. 2039 89
Wnt proteins are powerful regulators of cell proliferation and differentiation, and activation of the Wnt signalling pathway is involved in the pathogenesis of several types of human tumours.
Wnt inhibitory factor-1
(
WIF-1
) acts as a Wnt antagonist and
tumour suppressor
. Previous studies have shown that reducing expression of the
WIF-1
gene aberrantly activates Wnt signalling and induces the development of certain types of cancers. In the present study, we examined the expression of
WIF-1
in human primary glioblastoma multiforme (GBM) tumours. Studies using semiquantitative reverse transcription-polymerase chain reaction and immunohistochemical analysis revealed that
WIF-1
expression is lower in human GBM than in normal brain tissue. To clarify the role of
WIF-1
, we transfected U251 human glioblastoma-derived cells, which do not express
WIF-1
, with the pcDNA3.1-
WIF1
vector to restore
WIF-1
expression. The results of cell proliferation, colony formation and apoptosis assays, as well as flow cytometry, indicate that exogenous
WIF-1
has no effect on U251 cell apoptosis, but does arrest cells at the G(0)/G(1) phase and inhibit cell growth. Collectively, our data suggest that
WIF-1
is a potent inhibitor of GBM growth.
...
PMID:Wnt inhibitory factor-1 regulates glioblastoma cell cycle and proliferation. 2290 5
Ovarian cancer is the leading cause of death from gynaecologic tumours, but the molecular and especially epigenetic events underlying the transformation are poorly understood. Various methylation changes have been identified and show promise as potential cancer biomarkers. The aim of this study was to investigate promoter methylation of selected
tumour suppressor
genes in ovarian cancer by comparison with normal ovarian tissue. To search for epigenetic events we used methylation-specific multiplex ligation-dependent probe amplification to compare the methylation status of 44 tissue samples of ovarian cancer with 30 control samples. Using a 20% cut-off for methylation, we observed significantly higher methylation in genes NTKR1, GATA4 and
WIF1
in the ovarian cancer group compared with the control group. These findings could potentially be used in screening of ovarian cancer, and may have implications for future chemotherapy based on epigenetic changes.
...
PMID:Promoter methylation of GATA4, WIF1, NTRK1 and other selected tumour suppressor genes in ovarian cancer. 2374 74