The oncogenic proteins expressed in human cancer cells are exceedingly difficult targets for drug discovery due to intrinsic properties of the Ras GTPase switch. As a result, recent efforts have largely focused on inhibiting Ras-regulated kinase effector cascades, particularly the Raf/MEK/ERK and PI3 kinase/Akt/mTOR pathways. We constructed murine stem cell leukemia virus (MSCV) vectors encoding oncogenic K-RasD12 with additional second site amino acid substitutions that that impair PI3 kinase/Akt or Raf/MEK/ERK activation and performed bone marrow transduction/transplantation experiments in mice. In spite of attenuated signaling properties, defective K-Ras oncoproteins induced aggressive clonal T lineage acute lymphoblastic leukemia (T-ALL). These leukemias exhibited a high frequency of somatic Notch1 mutations, which is also true of human T-ALL. Multiple independent T-ALLs restored full oncogenic Ras activity by acquiring third site mutations within the viral KrasD12 transgenes. Other leukemias with undetectable PTEN and elevated phosphoryated Akt levels showed a similar gene expression profile to human early T progenitor (ETP) T-ALL. Expressing oncoproteins that are defective for specific functions is a general strategy for assessing requirements for tumor maintenance and uncovering potential mechanisms of drug resistance in vivo. In addition, our observation that defective Kras oncogenes regain potent cancer initiating activity strongly supports simultaneously targeting distinct components of Ras signaling networks in the substantial fraction of cancers with RAS mutations.
Defective K-Ras oncoproteins overcome impaired effector activation to initiate leukemia in vivo.
Specimen part, Cell line
View SamplesHere we explored how the human macrophage response to tumor necrosis factor (TNF) is regulated by human synovial fibroblasts, the representative stromal cell type in the synovial lining of joints that become activated during inflammatory arthritis. Genome-wide transcriptome analysis (RNAseq) showed that co-cultured synovial fibroblasts modulate the expression of approximately one third of TNF-inducible genes in macrophages, including expression of target genes in pathways important for macrophage survival and polarization towards an alternatively activated phenotype. This work furthers our understanding of the interplay between innate immune and stromal cells during an inflammatory response, one that is particularly relevant to inflammatory arthritis. Our findings also identify modulation of macrophage phenotype as a new function for synovial fibroblasts that may prove to be a contributing factor in arthritis pathogenesis. Overall design: Human CD14+ MCSF-differentiated macrophages were cultured with or without synovial fibroblasts in transwell chambers. TNF was added at Day 0, macrophages were harvested at Day 2. Total of 4 samples: (1) macrophages alone (2) macrophages with fibroblasts (3) macrophages with TNF (4) macrophages with fibroblasts and TNF. Macrophage RNA was purified using RNeasy mini kit (Qiagen). Tru-seq sample preparation kits (Illumina) were used to purify poly-A transcripts and generate libraries with multiplexed barcode adaptors. All samples passed quality control on a Bioanalyzer 2100 (Agilent). Paired-end reads (50 x 2 cycles, ~75x106 reads per sample) were obtained on an Illumina HiSeq 2500. The TopHat program was used to align the reads to the UCSC Hg19 human reference genome, while the Cufflinks program allowed for measurements of transcript abundance (represented by Fragments Per Kilobase of exon model per Million mapped reads (FPKM)).
Modulation of TNF-induced macrophage polarization by synovial fibroblasts.
No sample metadata fields
View SamplesCoinhibitory receptor blockade is a promising strategy to boost immunity against a variety of human cancers. However, many patients still do not benefit from this treatment, and responders often experience immune-related toxicities. These issues highlight the need for improved understanding of checkpoint blockade, but the T cell-intrinsic signaling pathways and gene expression profiles engaged during treatment are not well defined, particularly for combination approaches. We utilized a murine model of CD8+ T cell tolerance to address these issues.
Checkpoint blockade immunotherapy relies on T-bet but not Eomes to induce effector function in tumor-infiltrating CD8+ T cells.
Specimen part
View SamplesWe utilized whole genome sequencing of mRNA (RNA-seq) to understand the extent to which the senescence-associated secretory phenotype is regulated by p38MAPK Overall design: Examination of replicates of young, senescent or p38MAPK-inhibited senescent BJ human foreskin fibroblasts.
p38MAPK plays a crucial role in stromal-mediated tumorigenesis.
No sample metadata fields
View SamplesKLF5 is a basic transcription factor that regulates multiple biological processes, but its function in tumorigenesis appears contradictory in the current literature, with some studies showing tumor suppressor activity and others showing tumor promoting activity. In this study, we examined the function of Klf5 in prostatic tumorigenesis using mice with prostate specific deletion of Klf5 and Pten, both of which are frequently deleted in human prostate cancer. Histological and molecular analyses demonstrated that when one Pten allele was deleted, which causes mouse intraepithelial neoplasia (mPIN), Klf5 deletion accelerated the emergence and progression of mPIN. When both Pten alleles were deleted, which causes prostate cancer, Klf5 deletion promoted tumor growth and caused more severe morphological and molecular alterations, and homozygous deletion of Klf5 was more effective than hemizygous deletion. Unexpectedly, while Klf5 deletion clearly promoted tumorigenesis in luminal cells, it actually diminished the numbers of Ck5-positive basal cells in the Pten-null tumors. Klf5 deletion also increased the cell proliferation rate in tumors with Pten deletion, which involved extensive activation of the PI3K/AKT and MAPK mitogenic signaling pathways and inactivation of the p15 cell cycle inhibitor. Global gene expression and pathway analyses demonstrated that multiple mechanisms could be responsible for the tumor promoting effect of Klf5 deletion,
Klf5 deletion promotes Pten deletion-initiated luminal-type mouse prostate tumors through multiple oncogenic signaling pathways.
Sex, Age, Specimen part
View SamplesAtypical teratoid/rhabdoid tumor (ATRT) is a highly malignant CNS neoplasm whichprimarily occurs in children under three years of age. Due to poor outcomes with intense and toxicmultimodality treatment, new therapies are urgently needed. Histone deacetylase inhibitors (HDIs)have been evaluated as novel agents for multiple malignancies and have been shown to function asradiosensitizers. They act as epigenetic modifiers and lead to re-expression of inappropriatelyrepressed genes, proteins, and cellular functions. Due to the underlying chromatin remodeling genemutation in ATRT, HDIs are ideal candidates for therapeutic evaluation. To evaluate the role of HDIsagainst ATRT in vitro, we assessed the effect of drug treatment on proliferation, apoptosis, and geneexpression. Additionally, we examined HDI pretreatment as a radiosensitization strategy for ATRT.MTS and clonogenic assays demonstrated that HDI treatment significantly reduces the proliferativecapacity of BT-12 and BT-16 ATRT cells. Also, the HDI SNDX-275 was able to induce apoptosis in bothcell lines and induced p21Waf1/Cip1 protein expression as measured by Western blot. Evaluation ofdifferential gene expression by microarray and pathway analysis after HDI treatment demonstratedalterations of several key ATRT cellular functions. Finally, we showed that HDI pretreatmenteffectively potentiates the effect of ionizing radiation on ATRT cells as measured by clonogenic assay.These findings suggest that the addition of HDIs to ATRT therapy may prove beneficial, especiallywhen administered in combination with current treatment modalities such as radiation.
Histone deacetylase inhibition decreases proliferation and potentiates the effect of ionizing radiation in atypical teratoid/rhabdoid tumor cells.
Specimen part, Cell line
View SamplesThe characteristics of immune cells infiltrating pediatric brain tumors is largely unexplored. A better understanding of these characteristics will provide a foundation for development of immunotherapy for pediatric brain tumors.
Characterization of distinct immunophenotypes across pediatric brain tumor types.
Specimen part, Disease, Disease stage
View SamplesCongenital glioblastoma multiforme (cGBM) historically has been considered an aggressive tumor of infancy requiring extensive chemotherapy to achieve cure. We report on 4 patients at our institution with cGBMs who were treated with surgery and chemotherapy (carboplatin and etoposide every 21 days for 2-6 cycles). Four of four patients are progression free at a median time of 27.5 months (22-103 months). To characterize the molecular biology of cGBM, we compared the gene expression profiles of 3 cGBMs to 12 pediatric and 6 primary adult glioblastomas collected at our institution. Unsupervised hierarchical clustering showed cGBMs grouped together with other high-grade gliomas. cGBMs demonstrated marked similarity to both pediatric and adult GBMs, with only a total of 31 differentially expressed genes identified (FDR < 0.05). Unique molecular features of congenital GBMs identified included over-expression of multiple genes involved in glucose metabolism and tissue hypoxia pathways. Four tyrosine kinases were also mong the up-regulated genes (RET, RASGRF2, EFNA5, ALK). Thus, at our institution congenital GBMs, while similar both histologically and molecularly to other GBMs, appear to have a good prognosis with surgery in combination with relatively moderate chemotherapy. Further study is needed to determine if the few gene expression differences that were identified may contribute to the better survival seen in these tumors compared to pediatric or adult GBMs.
Clinical and molecular characteristics of congenital glioblastoma.
Sex, Disease, Disease stage
View SamplesEpendymoma, the 3rd most common brain tumor in children, recurs in approximately 50% of patients. There is currently no robust marker that predicts for recurrence, which is a significant clinical problem
Immune gene and cell enrichment is associated with a good prognosis in ependymoma.
Specimen part
View SamplesBone marrow stromal cells (BMSCs) were isolated from the femora and tibiae of irtTA-GBD*-TAg transgenic mice. Using cellular cloning we established skeletal progenitors with distinct differentiation properties and analysed their transcriptome. Unipotent osteogenic and adipogenic cells expressed specific transcriptional programs whereas bipotent clones combined expression of those genes and did not show a unique signature. Overall design: Expression profiling (RNA-seq) of two independent clones from different mice representing skeletal progenitors with the following characteristics: tripotent clones (Osteogenic, Adipogenic, Chondrogenic = OAC1 and OAC2); bipotent clones (Osteogenic, Adipogenic = OA1 and OA2); unipotent clones (Osteogenic = O1 and O2; Adipogenic = A1 and A2). Further, we prepared and sequenced pools of several other clones from these two mice, with the following properties: tripotent clones (Osteogenic, Adipogenic, Chondrogenic = OAC3); bipotent clones (Osteogenic, Adipogenic = OA3; Osteogenic, Chondrogenic = OC3; Adipogenic, Chondrogenic = AC3); unipotent clones (Osteogenic = O3; Adipogenic = A3).
Clonal Analysis Delineates Transcriptional Programs of Osteogenic and Adipogenic Lineages of Adult Mouse Skeletal Progenitors.
Specimen part, Cell line, Subject
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