Over-expression of the polycomb group gene BMI-1 is implicated in the pathogenesis of many human cancers. In this study, we investigate the role of BMI-1 as a functional oncogene in the Ewings Sarcoma Family of Tumors (ESFT), a highly aggressive group of bone and soft tissue tumors. Our data show that BMI-1 is highly expressed by the majority of primary ESFT and ESFT cell lines. However, in contrast to previous reports in other human cancer cell types, knockdown of BMI-1 in ESFT cell lines has no effect on cell survival. Instead, gain and loss of function studies in vitro and in vivo demonstrate that BMI-1 promotes the anchorage independent growth and tumorigenicity of ESFT. Importantly, we also find that modulation of BMI-1 alters the tumorigenicity of both p16-wild type and p16-null cell lines and that BMI-1-mediated effects on growth promotion are independent of CDKN2a repression. Gene expression profiling of ESFT cells following BMI-1 modulation reveals novel downstream effectors of BMI-1 function including key developmental, cell:cell and cell:matrix adhesion pathways. These data support a central role for BMI-1 in the pathogenesis of ESFT and reveal that p16-independent functions of BMI-1 are largely responsible for its oncogenic function in this tumor family.
BMI-1 promotes ewing sarcoma tumorigenicity independent of CDKN2A repression.
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View SamplesColon cancer is a major cause of cancer deaths in Western countries and is associated with diets high in red meat. Heme, the iron-porphyrin pigment of red meat, induces cytotoxicity of gut contents which injures surface cells leading to compensatory hyperproliferation of crypt cells. This hyperproliferation results in epithelial hyperplasia which increases the risk of colon cancer. In humans, a high red-meat diet increases Bacteroides spp in feces. Therefore, we simultaneously investigated the effects of dietary heme on colonic microbiota and on the host mucosa of mice. Whole genome microarrays showed that heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. Using 16S rRNA phylogenetic microarrays, we investigated whether bacteria play a role in this changed signaling. Heme increased Bacteroidetes and decreased Firmicutes in colonic contents. This shift was most likely caused by a selective susceptibility of Gram-positive bacteria to heme cytotoxic fecal water, which is not observed for Gram-negative bacteria, allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria most probably increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There was no functional change in the sensing of the bacteria by the mucosa, as changes in inflammation pathways and Toll- like receptor signaling were not detected. This unaltered host-microbe cross-talk indicates that the changes in microbiota did not play a causal role in the observed hyperproliferation and hyperplasia.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part
View SamplesPreviously, we showed that dietary heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. In this study we investigated whether bacteria play a role in this changed signaling. Dietary heme increased the Bacteroidetes and decreased the Firmicutes in colonic content. This shift was caused by a selective susceptibility of Gram-positive bacteria to the heme cytotoxic fecal waters, which is not observed for Gram-negative bacteria allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There were no signs of sensing of the bacteria by the mucosa, as changes in TLR signaling were not present. This lack of microbe-host cross talk indicated that the changes in microbiota do not play a causal role in the heme-induced hyperproliferation.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part, Treatment
View SamplesEwing sarcoma family tumors (ESFTs) are aggressive tumors of putative stem cell origin for which prognostic biomarkers and novel treatments are needed. We have previously shown that the polycomb gene BMI-1 functions as an oncogene in ESFT. In several human cancers, high expression of BMI-1 is associated with poor outcome. For the current study, we evaluated the significance of variable BMI-1 expression levels in a large cohort of primary ESFT. Immunohistochemical staining of 130 tumors revealed that BMI-1 is over-expressed by the vast majority of ESFT. However, in 20% of cases, BMI-1 levels are low to undetectable. Significantly, although clinical presentation and outcome were found to be similar between BMI-1-high and BMI-1-low tumors, gene expression profiling studies showed marked differences in their respective gene expression profiles. Gene specific enrichment analysis identified that several cancer-associated canonical biologic pathways, including IGF1, mTOR and WNT, are significantly down-regulated in BMI-1-low compared to BMI-1-high tumors. Consistent with these in vivo data, in vitro studies of IGF1-R inhibition showed that the growth inhibitory effects of IGF1-R blockade are diminished in BMI-1-low ESFT cells. ESFT that do not over-express BMI-1 represent a novel subclass with a distinct molecular profile and altered activation of cancer-associated pathways.
Ewing tumors that do not overexpress BMI-1 are a distinct molecular subclass with variant biology: a report from the Children's Oncology Group.
Specimen part
View SamplesMycosis fungoides (MF), the most common cutaneous T-cell lymphoma (CTCL), is a malignancy of mature, skin-homing T cells. Szary syndrome (Sz) is often considered to represent a leukemic phase of MF. In this study the pattern of numerical chromosomal alterations in MF tumor samples was defined using array-based CGH; simultaneously gene expression was analyzed using microarrays. Highly recurrent chromosomal alterations in MF include copy number gain of 7q36, 7q21-7q22 and loss of 5q13 and 9p21. This pattern characteristic of MF differs markedly from chromosomal alterations observed in Sz. Integration of data from array-based CGH and gene expression analysis yielded several candidate genes with potential relevance in the pathogenesis of MF. We confirmed that the FASTK and SKAP1 genes, residing in loci with recurrent gain, demonstrated increased expression. The RB1 and DLEU1 tumor suppressor genes showed diminished expression associated with loss. In addition, it was found that presence of chromosomal alterations on 9p21, 8q24 and 1q21-1q22 was associated with poor prognosis in patients with MF. This study provides novel insight into genetic alterations underlying MF. Furthermore, our analysis uncovered genomic differences between MF and Sz, which suggest that the molecular pathogenesis and therefore therapeutic requirements of these CTCLs may be distinct.
Oncogenomic analysis of mycosis fungoides reveals major differences with Sezary syndrome.
Specimen part
View SamplesWe recently reported an oncogenomics-guided screening approach designed to identify genetic drivers of early stage melanoma metastasis, and in this study we functionally validate the top-scoring candidate, homeobox transcription factor A1 (HOXA1), by demonstrating HOXA1s robust effects on melanoma cell invasion, metastasis and tumorigenicity. Transcriptome and pathway profiling analyses of cells expressing HOXA1 reveal up-regulation of factors involved in diverse cytokine pathways that include the TGF signaling axis, which we further demonstrate to be required for HOXA1-mediated cell invasion. Transcriptome profiling also informed HOXA1s ability to potently down-regulate expression of microphthalmia-associated transcription factor (MITF) and other genes required for melanocyte differentiation, suggesting a mechanism by which HOXA1 expression de-differentiates cells into a pro-invasive precursor cell state concomitant with TGF activation. Our analysis of publicly available datasets indicate that the HOXA1-induced gene signature successfully categorizes melanoma specimens based on their metastatic potential and, importantly, is capable of stratifying melanoma patient risk for metastasis based on expression in primary tumors.
HOXA1 drives melanoma tumor growth and metastasis and elicits an invasion gene expression signature that prognosticates clinical outcome.
Cell line
View SamplesWe recently reported an oncogenomics-guided screening approach designed to identify genetic drivers of early stage melanoma metastasis, and in this study we functionally validate the top-scoring candidate, homeobox transcription factor A1 (HOXA1), by demonstrating HOXA1s robust effects on melanoma cell invasion, metastasis and tumorigenicity. Transcriptome and pathway profiling analyses of cells expressing HOXA1 reveal up-regulation of factors involved in diverse cytokine pathways that include the TGF signaling axis, which we further demonstrate to be required for HOXA1-mediated cell invasion. Transcriptome profiling also informed HOXA1s ability to potently down-regulate expression of microphthalmia-associated transcription factor (MITF) and other genes required for melanocyte differentiation, suggesting a mechanism by which HOXA1 expression de-differentiates cells into a pro-invasive precursor cell state concomitant with TGF activation. Our analysis of publicly available datasets indicate that the HOXA1-induced gene signature successfully categorizes melanoma specimens based on their metastatic potential and, importantly, is capable of stratifying melanoma patient risk for metastasis based on expression in primary tumors.
HOXA1 drives melanoma tumor growth and metastasis and elicits an invasion gene expression signature that prognosticates clinical outcome.
Cell line
View SamplesClinical and genomic evidence support the view that the metastatic potential of a primary tumor may be dictated by transforming events acquired early in the tumorigenic process. It has been proposed that the presence of such pro-metastatic events in early-stage tumors reflects their additional capability to function as oncogenes. Here, to test this deterministic hypothesis and identify potential pro-metastasis oncogenes, we adopted a comparative oncogenomics-guided functional genetic screening strategy involving (i) global transcriptomic data from two genetically engineered mouse models of melanoma with contrasting metastatic potential, (ii) genomic and transcriptomic profiles of human primary and metastatic melanoma and (iii) an invasion screen in TERT-immortalized human melanocytes and melanoma cells in vitro as well as (iv) evidence of expression selection in human melanoma tissues. This integrated effort led to the identification of 6 genes that are both potently pro-invasive and oncogenic. Further, we show that one such pro-invasion oncogene, ACP5, can confer spontaneous metastasis in vivo, engages a key pathway governing metastasis and is prognostic in human primary melanomas.
Proinvasion metastasis drivers in early-stage melanoma are oncogenes.
Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Host Transcription Profile in Nasal Epithelium and Whole Blood of Hospitalized Children Under 2 Years of Age With Respiratory Syncytial Virus Infection.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThe goal of this experiment was to determine gene expresssion differences between neutrophils from either K14cre;CdhF/F;Trp53F/F mammary tumor-bearing mice or wild-type mice. Overall design: Neturophil expression profiles were compared between four wild-type mice and five K14cre;CdhF/F;Trp53F/F mice.
IL-17-producing γδ T cells and neutrophils conspire to promote breast cancer metastasis.
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