Project description:To explore the mechanisms downstream of NOTCH1 and PTEN in the control of leukemia cell growth, we performed expression profiling on NOTCH1 induced and Pten-positive T-ALL tumor cells infected with constitutively active AKT (myristoylated-AKT). Constitutive activation of AKT rescues the transcriptional programs induced by NOTCH1 inhibition in Pten-positive T-ALL cells We performed microarray gene expression analysis of GSI treatment in Pten WT NOTCH1 induced leukemias infected with constitutively active AKT (myristoylated-AKT) or empty vector.
Project description:To investigate the underlying mechanisms mediating resistance to NOTCH inhibition in Pten-null T-ALL tumor cells we performed gene expression profiling of isogenic Pten-positive and Pten-deleted leukemia lymphoblasts after acute treatment with DBZ in vivo. This analysis revealed that, while direct NOTCH1 target genes (such as Hes1, Dtx1, PtcrA, HeyL and Notch3) are effectively downregulated in both Pten-positive and Pten-deleted tumors, genetic ablation of Pten elicits a global reversal of much of the transcriptional effects of NOTCH inhibition. We performed microarray gene expression analysis of GSI treatment in isogenic Pten KO or WT NOTCH1 induced leukemias
Project description:To formally address the tumor suppressor activity of Sh2b3 in vivo, we tested the interaction between oncogenic NOTCH1 and Sh2b3 loss in a retroviral- transduction bone marrow transplantation model of NOTCH-induced T-ALL Forced expression of activated NOTCH1 in this model typically results in full leukemia transformation 5-10 weeks later. We performed microarray gene expression analysis of Sh2b3 wild type and Sh2b3–/– NOTCH1 induced leukemias
Project description:U87-EV human glioblastoma xenograft tumours is therapeutically treated by bevacizumab, a humanized anti-human VEGF mAb, or dibenzazepine (DBZ) when tumour is established in BALB/c SCID mice. At the end point, collect tumour samples and extracted total RNA for microarray to investigate the gene profile changes compared to control. These include the genes from human tumour cells and mouse host stroma cells. 5 control, 5 dibenzazepine-treated, and 4 bevacizumab-treated samples
Project description:To model the effect of Pten loss on breast cancer, we deleted Pten using a floxed allele and the deleter lines MMTV-Cre(NLST), which targets stem/bi-potent progenitor cells, and WAP-Cre, which targets CD24-positive, pregnancy-identified stem cells/alveolar progenitors. Mammary tumors were detected in WAP-Cre:Ptenf/f females with a latency of 15.2 months. By 18 months, nearly all mice had succumbed to cancer. MMTV-Cre:Ptenf/f mice developed mammary tumors after a longer latency of 26.4 months and reduced penetrance (70%) compared to WAP-Cre:Ptenf/f mice. Tumors from both models were heterogeneous, consisting primarily of differentiated adenocarcinoma (adenomyoepithelioma; ~70%) and adenosquamous carcinoma (20-25%). In addition, a small fraction of tumors was classified as acinar and poorly differentiated adenocarcinoma (4-7%) and adenosarcoma (3-4%). To test the consequences of combined Pten and p53 gene mutation on breast cancer, we deleted both genes via MMTV-Cre or WAP-Cre. Kaplan-Meier tumor free survival curves revealed that WAP-Cre:Ptenf/f:p53f/f and MMTV-Cre:Ptenf/f:p53f/f females developed tumors with reduced latency of 11.3 and 9.8 months, compared with 15.2, 26.4, and 16.9 months for single-mutant WAP-Cre:Ptenf/f, MMTV-Cre:Ptenf/f or MMTV-Cre:p53f/f mice, respectively. In contrast to the heterogeneity of Pten tumors and small percentage of adenosarcomas in these mice, ~70% of Pten:p53 lesions were histologically classified as adeno-sacrcomatoid-like or mesenchymal-like breast cancer, with the rest exhibiting mixed mesenchymal plus adenocarcinomas and differentiated adenocarcinomas. The adeno-sacrcomatoid-like tumors expressed the mesenchymal markers vimentin, K5, SMA, N-cadherin and desmin but not ER, as well as islands of luminal-like K18 expressing cells surrounded by a layer of K14-positive cells. We used microarrays to detect differentially expressed genes in the Pten:p53 double-knock-out vs Pten or p53 single deletions Total RNA was extracted from tumors developed by double Trizol method and hybridized on Affymetrix microarrays.
Project description:Diffuse large B-cell lymphoma (DLBCL) represents a heterogeneous diagnostic category with distinct molecular subtypes that can be deM-oM-,M-^Aned by gene expression proM-oM-,M-^Aling. However, even within these deM-oM-,M-^Aned subtypes, heterogeneity prevails. To further elucidate the pathogenesis of these entities, we determined the expression of the tumor suppressor phosphatase and tensin homolog (PTEN) in 248 primary DLBCL patient samples. These analyses revealed that loss of PTEN was detectable in 55% of germinal center B-cell-like (GCB) DLBCLs, whereas this abnormality was found in only 14% of non-GCB DLBCL patient samples. In GCB DLBCL, the PTEN status was inversely correlated with activation of the oncogenic PI3K/ protein kinase B (AKT) pathway in both DLBCL cell lines and primary patient samples. Reexpression of PTEN induced cytotox- icity in PTEN-deM-oM-,M-^Acient GCB DLBCL cell line models by inhibiting PI3K/AKT signaling, indicating an addiction to this pathway in this subset of GCB DLBCLs. PI3K/AKT inhibition induced down-regulation of the transcription factor MYC. Reexpression of MYC rescued GCB DLBCL cells from PTEN-induced toxicity, identifying a regulatory mechanism of MYC expression in DLBCL. Finally, pharmacologic PI3K inhibition resulted in toxicity selectively in PTEN-deM-oM-,M-^Acient GCB DLBCL lines. Collectively, our results indicate that PTEN loss deM-oM-,M-^Anes a PI3K/ AKT-dependent GCB DLBCL subtype that is addicted to PI3K and MYC signaling and suggest that pharmacologic inhibition of PI3K might represent a promising therapeutic approach in these lymphomas. This GEO dataset is comprised of a) GEP measurements for 34 primary DLBCL patient samples plus two reference samples, b) 8 paired GEP measurements of the HT DLBCL cell line and c) aCGH measurements for two DLBCL cell lines in addition to previously published cell lines in GSE43272 (i.e., Sample GSM1059798). All of these data were used in the paper cited below.
Project description:NOTCH1 is a transcription factor involved in T-cell development and mutations that occur in NOTCH1 gene affects more than 60% of patients affected by T-cell acute lymphoblastic leukemia (T-ALL). In order to identify genes and pathways regulated following NOTCH1 inhibition in T-ALL, murine NOTCH1-induced T-cell leukemia were treated with a NOTCH1 inhibitor (DBZ, Dibenzazepine). Tumors were established in irradiated C57BL/6 mice injected with lineage negative progenitors cells transduced with a mutated NOTCH1 allele (HD-ΔPEST NOTCH1). Mice were treated three times, 8 hours apart, with vehicle only (DMSO) or DBZ (5mg/Kg). Total RNA was extracted from tumor samples (spleens of sick mice) and hybridized on Agilent SurePrint G3 Mouse GE 8x60K arrays. Each sample was derived from a different mouse (n=3 mice/group). Raw microarray data and results of differential expression analysis are available together with the applied protocols.
Project description:U87-EV human glioblastoma xenograft tumours is therapeutically treated by bevacizumab, a humanized anti-human VEGF mAb, or dibenzazepine (DBZ), when tumour is established in BALB/c SCID mice. At the end point, collect tumour samples and extracted total RNA for microarray to investigate the gene profile changes compared to control. These include the genes from human tumour cells and mouse host stroma cells. 3 control samples, 3 dibenzazepine-treated samples, 3 bevacizumab-treated samples
Project description:WAP-Cre:Ptenf/f:p53lox.stop.lox_R270H composite mice were generated by genetic crossing. In these mice, Pten is deleted and a R270H p53 mutation in the DNA binding domain is induced upon expression of Cre recombinase in pregnancy-identified alveolar progenitors. Tumors were characterized by histology, marker analysis, various bioinformatics methods, high-throughput (HTP) FDA-drug screen as well as orthotopic injection to quantify tumor initiating cells (TICs) and tail-vein injection to identify lung-metastasis. Expression data comparing 2 types of Pten-deficient tumors (spindle and poorly differentiated) with other modles of mouse mammary tumors 2 types of Pten deletion plus p53-R270H mutation tumors (spindle and poorly differentiated) was compared with MMTV-Neu, Spindle Pten-p53-deficient tumors, and wild-type mammary gland cells.
Project description:1. Comparison of gene expression profiles of normal prostates, hyperplastic prostates (4-5 month old mice) and prostate tumors (>10 month old mice) isolated from PSA-Cre;Pten-loxP/loxP mice 2.Comparison of the gene expression profiles and molecular subtyping of prostate tumors isolated from targeted Pten knockout mice