This SuperSeries is composed of the SubSeries listed below.
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesCCAR2 is a nuclear protein recently emerged as a pivotal player of the DNA damage response since it has been found involved in both apoptosis induction and DNA repair. Differently, its role in tumorigenesis and cancer progression is still elusive. In our studies we found that CCAR2 depletion impairs the proliferation of human cancer cell lines, but leaves unaffected the growth of normal immortalized cells. To better investigate this point we performed a genome wide gene expression analyses in U2OS and BJ-hTERT depleted of CCAR2 and we found that loss of this protein causes the deregulation of genes implicated in the AKT pathway specifically in U2OS cells, but not in BJ-hTERT. In accordance with these results we found a reduction in AKT activation in all the tested cancer cell lines depleted of CCAR2, but not in the normal ones. The defective activation of AKT is caused by the upregulation of TRB3 gene in cancer cells depleted of CCAR2 and finally results in the reduction of GSK3 phosphorylation, prevention of G1/S transition and inhibition of cancer cell growth.
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesCCAR2 is a nuclear protein recently emerged as a pivotal player of the DNA damage response since it has been found involved in both apoptosis induction and DNA repair. Differently, its role in tumorigenesis and cancer progression is still elusive. In our studies we found that CCAR2 depletion impairs the proliferation of human cancer cell lines, but leaves unaffected the growth of normal immortalized cells. To better investigate this point we performed a genome wide gene expression analyses in U2OS and BJ-hTERT depleted of CCAR2 and we found that loss of this protein causes the deregulation of genes implicated in the AKT pathway specifically in U2OS cells, but not in BJ-hTERT. In accordance with these results we found a reduction in AKT activation in all the tested cancer cell lines depleted of CCAR2, but not in the normal ones. The defective activation of AKT is caused by the upregulation of TRB3 gene in cancer cells depleted of CCAR2 and finally results in the reduction of GSK3 phosphorylation, prevention of G1/S transition and inhibition of cancer cell growth.
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation.
Cell line
View SamplesThe estrogen-dependence of breast cancer has long been recognized, however, the role of 17-estradiol (E2) in cancer initiation was not known until we demonstrated that it induces complete neoplastic transformation of the human breast epithelial cells MCF-10F. E2-treatment of MCF-10F cells progressively induced high colony efficiency and loss of ductulogenesis in early transformed (trMCF) cells and invasiveness in Matrigel invasion chambers. The cells that
Epithelial to mesenchymal transition in human breast epithelial cells transformed by 17beta-estradiol.
No sample metadata fields
View SamplesPTEN loss or PI3K/AKT signaling pathway activation correlates with human prostate cancer progression and metastasis. However, in preclinical murine models, deletion of Pten alone fails to mimic the significant metastatic burden that frequently accompanies the end stage of human disease. To identify additional pathway alterations that cooperate with PTEN loss in prostate cancer progression, we surveyed human prostate cancer tissue microarrays and found that the RAS/MAPK pathway is significantly elevated both in primary and metastatic lesions. In an attempt to model this event, we crossed conditional activatable K-rasG12D/WT mice with the prostate conditional Pten deletion model we previously generated. Although RAS activation alone cannot initiate prostate cancer development, it significantly accelerated progression caused by PTEN loss, accompanied by epithelial-to-mesenchymal transition (EMT) and macrometastasis with 100% penitence. A novel stem/progenitor subpopulation with mesenchymal characteristics was isolated from the compound mutant prostates, which was highly metastatic upon orthotopic transplantation. Importantly, inhibition of RAS/MAPK signaling by PD325901, a MEK inhibitor, significantly reduced the metastatic progression initiated from transplanted stem/progenitor cells. Collectively, these data indicate that activation of RAS/MAPK signaling serves as a potentiating second hit to alteration of the PTEN/PI3K/AKT axis and co-targeting both pathways is highly effective in preventing the development of metastatic prostate cancers.
Pten loss and RAS/MAPK activation cooperate to promote EMT and metastasis initiated from prostate cancer stem/progenitor cells.
Specimen part
View SamplesEpigenetic mechanisms contribute to deregulated gene expression of hematopoietic progenitors in Myelodysplastic Syndromes (MDS). Hypomethylating agents are able to improve peripheral cytopenias in MDS patients. To identify critical gene expression changes induced by hypomethylating agents, we analyzed gene expression profiling (GEP) of myelodysplastic and normal CD34+ hematopoietic stem cells treated in vitro with or without decitabine. Four MDS and two untreated early stage Hodgkins lymphomas were analyzed for GEP. Mock treated CD34+ stem cells segregate according to diagnosis and karyotype. After decitabine treatment, gene expression changes were more consistent on MDS CD34+ cells with abnormal kayotype. Comparing decitabine-induced genes with those found down-regulated in mock-treated MDS cells, we identified a list of candidate tumor suppressor genes in MDS. By real-time RT-PCR we confirmed expression changes for three selected genes CD9, CXCR4 and GATA2 in 12 MDS patients and 4 controls. CD9 was widely repressed in most MDS CD34+ cell samples, although similar levels of methylation were found in both normal and MDS total bone marrows. CXCR4 promoter methylation was absent in total bone marrows from 36 MDS patients. In conclusion, changes in gene expression changes induced by hypomethylating treatment are more pronounced in CD34+ cells from abnormal karyotype.
Gene expression profiling of myelodysplastic CD34+ hematopoietic stem cells treated in vitro with decitabine.
Sex, Age, Specimen part, Disease
View SamplesIt has long been known that leukemic cells disrupt normal patterns of blood cell formation, but little is understood about mechanisms. It has generally been assumed that normal hematopoietic stem and progenitor cells (HSPC) are simply out-competed for space by malignant cells. We designed a strategy to determine if leukemic cells alter intrinsic properties and functions of normal HSPCs. Chimeric mice were generated by transplantation of normal marrow and marrow from an inducible transgenic model of chronic myelogenous leukemia (CML). With induction of CML, the composition of the marrow changed dramatically, and normal HSPCs divided more readily and lost their ability to produce lymphocytes. In contrast, only modest changes were recorded in numbers of normal hematopoietic stem cells (HSCs). However, these stem cells were not unscathed, and had reduced reconstitution and self-renewal potential upon transplantation. Interestingly, the normal bystander cells acquired gene expression patterns resembling their neighboring malignant counterparts. This suggested that much of the leukemia signature is mediated by extrinsic factors in the environment.
Treatment of chronic myelogenous leukemia by blocking cytokine alterations found in normal stem and progenitor cells.
Specimen part
View SamplesPI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589. Overall design: RNA was extracted from pooled Epithelial, EMT and Mesenchymal-like tumor cells isolated by FACS sorting CD45-CD31-Ter119-EpCAM+GFP-, CD45-CD31-Ter119-EpCAM+GFP+, and CD45-CD31-Ter119-EpCAM-GFP+ cells, respectively, from the prostates of 10-12 week old Pb-Cre+/-;PtenL/L;KrasG12D/+;Vim-GFP (CPKV) mice (n=17) and separated into two technical replicates. Paired-end sequencing data with read lengths of 100 bp were generated using the Illumina HiSeq2000 system.
HDAC inhibition impedes epithelial-mesenchymal plasticity and suppresses metastatic, castration-resistant prostate cancer.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrated cross-species transcriptional network analysis of metastatic susceptibility.
Specimen part
View SamplesMouse genetic crosses were established between the PyMT model of metastatic breast cancer and AKXD strain. Tumors were harvested from the animals for gene expression analysis to identify genes and network modules associated with progression to distant metastatic disease.
Integrated cross-species transcriptional network analysis of metastatic susceptibility.
Specimen part
View Samples