The molecular events at the basis of prion diseases are characterized by the involvement of several genes which are differentially regulated during the onset and the progression of the infection. Gene expression profiling studies are a powerful tool for the development of preclinical diagnostic tests. Most of the studies performed up to date utilized tissues which are not suitable for a future perspective of a rapid analysis of the infected animals and patients.
Whole Blood Gene Expression Profiling in Preclinical and Clinical Cattle Infected with Atypical Bovine Spongiform Encephalopathy.
Sex, Specimen part
View SamplesMutations in Hedgehog (Hh) pathway genes, leading to constitutive activation of Smoothened (Smo), occur in sporadic medulloblastoma, the most common brain cancer in children. Antagonists of Smo induce tumor regression in mouse models of medulloblastoma and hold great promise for targeted therapy for this tumor. However, acquired resistance has emerged as one of the major challenges of targeted cancer therapy. Here, we describe novel mechanisms of acquired resistance to Smo antagonists in medulloblastoma. NVP-LDE225, a potent and selective Smo antagonist, inhibits Hh signaling and induces tumor regressions in allograft models of medulloblastoma that are driven by mutations of Patched (Ptch), a tumor suppressor in the Hh pathway. However, after long-term treatment, evidence of acquired resistance was observed. Genome-wide profiling of resistant tumors revealed distinct mechanisms to evade the inhibitory effects of Smo antagonists. Chromosomal amplification of Gli2, a downstream effector of Hh signaling, reactivated Hh signaling and restored tumor growth. Analysis of pathway gene-expression signatures selectively deregulated in resistant tumors identified increased phosphoinosite-3-kinase (PI3K) signaling as another potential resistance mechanism. Probing the functional relevance of increased PI3K signaling, we showed that the combination of NVP-LDE225 with the dual PI3K/mTOR inhibitor NVP-BEZ235 markedly delayed the development of resistance. Our findings have important clinical implications for future treatment strategies in medulloblastoma.
Interfering with resistance to smoothened antagonists by inhibition of the PI3K pathway in medulloblastoma.
Treatment
View Sampleswe report additional phenotypes of mHtt mice that are modified in Pin1 knock-out mice Overall design: RNAs from the striatum of three mice of 12 months of age were purified for each of the genotypes (PinWT/HttWT; PinKO/HttWT; PinWT/HttKI; PinKO/HttKi) to carry out gene expression profiling
Effects of Pin1 Loss in Hdh(Q111) Knock-in Mice.
No sample metadata fields
View SamplesWe have carried out transcriptional profile analysis in macroH2A knockdown cells (Namalwa B cells and HeLa cells) and demonstrated that this histone variant plays positive and negative roles in transcription. We also demonstrated the role of macroH2A in regulating the response to Sendai Virus infection.
Composite macroH2A/NRF-1 Nucleosomes Suppress Noise and Generate Robustness in Gene Expression.
Cell line, Treatment
View SamplesIschemic preconditioning represents the most powerful mechanism of cardioprotection. The mechanisms mediating the second window of preconditioning (SWOP) differ from those mediating first window preconditioning. We hypothesized that chronic ischemia induced by repetitive ischemic stimuli would be mediated by yet different molecular mechanisms. Accordingly, conscious, chronically instrumented pigs (n=5/group) were submitted to a protocol of classical SWOP (two 10-min episodes of coronary artery occlusion followed by 24 hr reperfusion) and compared to pigs submitted to repetitive occlusion/reperfusion (RCO) by repeating 6 episodes of SWOP 12 hrs apart, and to a model of repetitive coronary stenosis (RCS), in which 6 episodes of 90 min coronary stenosis were performed 12 hrs apart. Microarray analysis was performed on the three models. There was an 85% homology in gene response between both models of RCO and RCS, whereas SWOP was qualitatively different. Both models of RCO and RCS but not SWOP showed a down-regulation of genes encoding proteins involved in oxidative metabolism, and an up-regulation of genes involved in protein synthesis and unfolded protein response, autophagy, heat shock response, protein secretion, and a strong activation of the NF-B signaling pathway. Two thirds of the genes regulated in the three models showed a gradual pattern of up- or down-regulation, in which RCO was quantitatively intermediary between RCS and SWOP. Therefore, the regulated genes in response to chronic, repetitive episodes of ischemia differ radically from classical first or second window preconditioning.
Molecular mechanisms mediating preconditioning following chronic ischemia differ from those in classical second window.
Sex, Specimen part
View SamplesSome of the functions and mechanisms of PPAR?-mediated regulation of vascular homeostasis have been revealed, the potential role of PPAR? in angiogenesis is obscure. In human ECs, PPAR?-deficiency was studied using siRNA strategy and RNA sequencing was utilized to reveal angiogenesis-associated targets for PPARg. Overall design: Our aim is to reveal the possible role of PPARy in angiogenesis.
Loss of PPARγ in endothelial cells leads to impaired angiogenesis.
No sample metadata fields
View SamplesMucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare subtype of renal cell carcinoma with distinctive morphologic and cytogenetic features. Here we carry out whole exome and transcriptome sequencing of a multi-institutional cohort of MTSCC (n=22). We demonstrate the presence of either biallelic loss of Hippo pathway tumor suppressor genes (TSGs) and/or evidence of alteration of Hippo pathway genes in 85% of samples. PTPN14 (31%) and NF2 (22%) were the most commonly implicated Hippo pathway genes while other genes such as SAV1 and HIPK2 were also involved in a mutually exclusive fashion. Mutations in the context of recurrent chromosomal losses amounted to bi-allelic alterations in these TSGs. As a read-out of Hippo pathway inactivation, a majority of cases (90%) exhibited increased nuclear YAP1 protein expression. To identify transcriptional targets of the Hippo pathway in kidney we performed PTPN14 knockdown followed by RNA-seq in 2 kidney cancer cell lines (CAKI-1 and A-704) and a normal kidney epithelial cell line (HK-2). PTPN14 siRNAs were first functionally validated in a MCF-7 TEAD reporter luciferase stable cell line. Both siRNAs showed comparable knockdown efficiency and significantly increased luciferase reporter activity. In 2 of the kidney cell lines PTPN14 knockdown increased cell proliferation compared to non-target controls. While we observed excellent correlation between genes dysregulated by either PTPN14 or LATS1 knockdown within each cell line (HK2, CAKI-1 and A704), the overlap across the 3 cell lines was only 23 genes. Further, these 23 genes did not show concordant differential expression in MTSCC tumors. Overall, these results illustrate the marked tissue specificity of Hippo pathway targets.Finally, taken together, nearly all cases of MTSCC exhibit some evidence of Hippo pathway dysregulation. Overall design: Cell lines (CAKI-1, HK2 or A704) were either transfected with 2 independent siRNAs or non-target controls. Forty eight hours post transcription total RNA was isolated and subjected to RNA-seq analysis
Biallelic Alteration and Dysregulation of the Hippo Pathway in Mucinous Tubular and Spindle Cell Carcinoma of the Kidney.
Specimen part, Disease, Disease stage, Cell line, Subject
View SamplesThis study examines the sites of HIV integration in quiescent CD4 T cells and compares them to activated T cells. The expression patterns of the sites hosting integration events were determined using microarray analysis data from quiescent and activated CD4 T cells.
Human immunodeficiency virus integration efficiency and site selection in quiescent CD4+ T cells.
No sample metadata fields
View SamplesTo identify the potential ovarian cancer stem cell gene expression profile from isolated side population of fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma
Identification of a potential ovarian cancer stem cell gene expression profile from advanced stage papillary serous ovarian cancer.
Specimen part
View SamplesMicroarray data allowed detection of genes that are highly expressed in the pineal gland.
A new cis-acting regulatory element driving gene expression in the zebrafish pineal gland.
Sex
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