Global DNA hypomethylation and DNA hypermethylation of promoter regionsincluding tumor suppressor genesare frequently detected in human cancers. Although many studies have suggested a contribution to carcinogenesis, it is still unclear whether the aberrant DNA hypomethylation observed in tumors is a consequence or a cause of cancer. We found that overexpression of Stella (also known as PGC7, Dppa3), a maternal factor required for the maintenance of DNA methylation in early embryos, induced global DNA hypomethylation and transformation in NIH3T3 cells. This hypomethylation was due to the binding of Stella to Np95 (also known as Uhrf1, ICBP90) and the subsequent impairment of Dnmt1 localization. In addition, enforced expression of Stella enhanced the metastatic ability of B16 melanoma cells through the induction of metastasis-related genes by inducing DNA hypomethylation of their promoter regions. Such DNA hypomethylation itself causes cellular transformation and metastatic ability. These data provide new insight into the function of global DNA hypomethylation in carcinogenesis.
Global DNA hypomethylation coupled to cellular transformation and metastatic ability.
Cell line
View SamplesWnt/-catenin is involved in every aspect of embryonic development and in the pathogenesis of many human diseases, and is also implicated in organ fibrosis. However, the role of -catenin-mediated signaling on liver fibrosis remains unclear. To explore this issue, the effects of PRI-724, a selective inhibitor of the cAMP-response element-binding protein-binding protein (CBP)/-catenin interaction, on liver fibrosis were examined using carbon tetrachloride (CCl4)- or bile duct ligation (BDL)-induced mouse liver fibrosis models. Following repetitive CCl4 administrations, the nuclear translocation of -catenin was observed only in the non-parenchymal cells in the liver. PRI-724 treatment reduced the fibrosis induced by CCl4 or BDL, accompanied by the suppression of S100A4 expression, a CBP/-catenin transcript. C-82, an active form of PRI-724, inhibited the activation of isolated primary mouse quiescent hepatic stellate cells (HSCs) and promoted cell death in culture-activated HSCs. During the fibrosis resolution period, an increase in F4/80+ CD11b+ and Ly6Clow CD11b+ macrophages was induced by CCl4 and was sustained for two weeks thereafter, even after having stopped CCl4 treatment. PRI-724 accelerated the resolution of CCl4-induced liver fibrosis, and this was accompanied by increased matrix metalloproteinase (MMP)-9, MMP-2, and MMP-8 expression in intrahepatic leukocytes. These results suggest that the inhibition of CBP/-catenin suppresses liver fibrosis through the inhibition of HSCs activation, the induction of activated HSC death, and the production of MMPs from macrophages. Thus, targeting the CBP/-catenin interaction may become a new therapeutic strategy in treating liver fibrosis.
No associated publication
Treatment
View SamplesDe novo lipogenesis is activated in most cancers. Several lipogenic enzymes are implicated in oncogenesis and represent potential cancer therapeutic targets. RNA interference-mediated depletion of ATP citrate lyase (ACLY), the enzyme that catalyzes the first step of de novo lipogenesis, leads to growth suppression in a subset of human cancer cells. Here we demonstrate the molecular basis and potential biomarkers for ACLY-targeting therapy. First, suppression of cancer cell growth by ACLY depletion involves down-regulation of fatty acid elongase ELOVL6 at the transcriptional level. Lipid profiling revealed that ACLY depletion alters fatty acid composition in triglyceride; increased palmitate and decreased longer fatty acids, in accordance with ELOVL6 down-regulation. Second, ACLY depletion increases reactive oxygen species (ROS), whereas addition of antioxidant reduces ROS and attenuates the growth suppression. Third, ACLY depletion or ROS stimulation induce phosphorylation of AMP-activated protein kinase (AMPK), a sensor of energy and lipid metabolism. Analysis of various cancer cell lines revealed that the levels of AMPK phosphorylation (p-AMPK) correlate with the basal ROS levels, and that cancer cells with low basal p-AMPK (i.e., low basal ROS) levels are highly susceptible to ACLY depletion-mediated growth suppression. Finally, in clinical colon cancer tissues, p-AMPK levels are significantly decreased in aggressive tumors and correlate with the levels of 8-hydroxydeoxyguanosine, a hallmark of ROS stimulation. Together, these data suggest that ACLY inhibition suppresses cancer growth via palmitate-mediated lipotoxicity, and p-AMPK could be a predictive biomarker for its therapeutic outcome.
No associated publication
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
TET2 repression by androgen hormone regulates global hydroxymethylation status and prostate cancer progression.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Androgen-induced Long Noncoding RNA (lncRNA) SOCS2-AS1 Promotes Cell Growth and Inhibits Apoptosis in Prostate Cancer Cells.
Specimen part, Cell line
View SamplesProstate cancer is the most common cancer in men and Androgen receptor (AR) downstream signalings promote prostate cancer cell proliferation. We identified androgen-regulated long non-coding RNA, CTBP1-AS, located in the antisese region of CTBP1 gene. CTBP1-AS activate AR signaling by epigenetically repress AR-associated cofactors such as CTBP1 by interactign with RNA-binding protein PSF and recruiting HDAC complex to the target promoters.
No associated publication
Specimen part, Cell line
View SamplesProstate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. Oct1 is an AR interacting partner and regulates the transcriptional activity of AR.
No associated publication
Cell line
View SamplesProstate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified a novel androgen-regulated long non-coding (lnc) RNA, SOCS2-AS1.
Androgen-induced Long Noncoding RNA (lncRNA) SOCS2-AS1 Promotes Cell Growth and Inhibits Apoptosis in Prostate Cancer Cells.
Specimen part, Cell line
View SamplesProstate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified androgen-regulated genes, CTBP2, FOXP1 and RUNX1. These factors interact with AR ligand dependently.
CtBP2 modulates the androgen receptor to promote prostate cancer progression.
Cell line, Treatment
View Samples