This SuperSeries is composed of the SubSeries listed below.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Specimen part, Cell line, Treatment
View SamplesAcquired resistance to cancer drug therapies almost always occurs in advanced-stage patients even following a significant response to treatment. In addition to mutational mechanisms, various non-mutational resistance mechanisms have now been recognized. We previously described a chromatin-mediated subpopulation of reversibly drug-tolerant persisters (DTPs) that is dynamically maintained within a wide variety of tumor cell populations. Here, we explored a potential role for microRNAs in such transient drug tolerance. Functional screening of 879 human microRNAs revealed miR-371-3p as a potent suppressor of drug tolerance. PRDX6 (peroxiredoxin 6) was identified as a key target of miR-371-3p in establishing drug tolerance by regulating PLA2/PKC activity and reactive oxygen species. PRDX6 expression is associated with poor prognosis in cancers of multiple tissue origins. These findings implicate miR-371-3p as a suppressor of PRDX6 and suggest that co-targeting of PRDX6 or modulating miR-371-3p expression together with targeted cancer therapies may delay or prevent acquired drug resistance.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Cell line, Treatment
View SamplesAcquired resistance to cancer drug therapies almost always occurs in advanced-stage patients even following a significant response to treatment. In addition to mutational mechanisms, various non-mutational resistance mechanisms have now been recognized. We previously described a chromatin-mediated subpopulation of reversibly drug-tolerant persisters (DTPs) that is dynamically maintained within a wide variety of tumor cell populations. Here, we explored a potential role for microRNAs in such transient drug tolerance. Functional screening of 879 human microRNAs revealed miR-371-3p as a potent suppressor of drug tolerance. PRDX6 (peroxiredoxin 6) was identified as a key target of miR-371-3p in establishing drug tolerance by regulating PLA2/PKC activity and reactive oxygen species. PRDX6 expression is associated with poor prognosis in cancers of multiple tissue origins. These findings implicate miR-371-3p as a suppressor of PRDX6 and suggest that co-targeting of PRDX6 or modulating miR-371-3p expression together with targeted cancer therapies may delay or prevent acquired drug resistance.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Specimen part, Cell line, Treatment
View SamplesEphB receptors regulate the proliferation and positioning of intestinal stem and progenitor cells. In addition, they can act as tumor promoters for adenoma development, but suppress progression to invasive carcinoma. Here we used imatinib to abrogate Abl kinase activity in ApcMin/+ mice and in mice with LGR5+ stem cells genetically targeted for APC. This treatment inhibited the tumor-promoting effects of EphB signaling without attenuating EphB-mediated tumor suppression, demonstrating the role of EphB signaling in intestinal tumor initiation. The investigated treatment regimen extended the lifespan of ApcMin/+ mice, and reduced cell proliferation in cultured slices of adenomas from FAP patients. These findings connect the EphB signaling pathway to the regulation of intestinal adenoma initiation via Abl kinase. Our findings may have clinical implications for pharmacological therapy against adenoma formation and cancer progression in patients predisposed to develop colon cancer.
An EphB-Abl signaling pathway is associated with intestinal tumor initiation and growth.
Specimen part
View SamplesMicroRNAs predominantly decrease gene expression; however, specific mRNAs are translationally upregulated in quiescent (G0) mammalian cells and immature Xenopus laevis oocytes by an FXR1a-associated microRNP (microRNA-protein complex) that lacks the microRNP repressor, GW182. We conducted global proteomic analysis in THP1 cells depleted of FXR1 to globally identify activation targets of more than one microRNA, since FXR1 is required for microRNAmediated translation activation in THP1 G0 cells by FXR1-microRNPs.Since proteomic data changes could also be due to changes at the RNA level, total RNA levels in FXR1knockdown compared to control shRNA cells were examined in parallel by microarray analysis using Affymetrix Human GeneChip 2.0 ST.
A Specialized Mechanism of Translation Mediated by FXR1a-Associated MicroRNP in Cellular Quiescence.
Specimen part, Cell line
View SamplesNon-tumor-reactive T cells are characterized by the inabilitzy to lyse autologous tumor cells, low to intermediate avidity TCRs and lack of NY-ESO-1 peptide tetramer binding. However most strikingly, non-tumor-reactive T cells are characterized by a molecular program associated with division arrest anergy with elevated expression of the inhibitory molecule p27kip1. This is accompanied by elevated expression of inhibitory molecules and reduced levels of transcription factors involved in T cell activation. Frequency analysis of the inhibited T cell population using the established molecular fingerprint as a novel biomarker might be applied for cancer vaccine development and optimization.
Cancer vaccine enhanced, non-tumor-reactive CD8(+) T cells exhibit a distinct molecular program associated with "division arrest anergy".
No sample metadata fields
View SamplesBased on studies in knockout mice, several inhibitory factors such as TGF-beta, IL-10, or CTLA-4 have been implicated as gate keepers of adaptive immune responses. Lack of these inhibitory molecules leads to massive inflammatory responses mainly mediated by activated T cells. In humans, the integration of these inhibitory signals for keeping T cells at a resting state is less well understood. To elucidate this regulatory network we assessed early genome-wide transcriptional changes during serum deprivation in human mature CD4+ T cells. The most striking observation was a "TGF-beta loss signature" defined by downregulation of many known TGF-beta target genes. Moreover, numerous novel TGF-beta target genes were identified that are under the suppressive control of TGF-beta. Expression of these genes was upregulated once TGF-beta signaling was lost during serum deprivation and again suppressed upon TGF-beta reconstitution. Constitutive TGF-beta signaling was corroborated by demonstrating phosphorylated SMAD2/3 in resting human CD4+ T cells in situ, which were dephosphorylated during serum deprivation and re-phosphorylated by minute amounts of TGF-beta. Loss of TGF-beta signaling was particularly important for T cell proliferation induced by low-level T cell receptor and costimulatory signals. We suggest TGF-beta to be the most prominent factor actively keeping human CD4+ T cells at a resting state.
Human resting CD4+ T cells are constitutively inhibited by TGF beta under steady-state conditions.
No sample metadata fields
View SamplesIncreased antigen cross-presentation but impaired cross-priming after activation of PPAR is mediated by up-regulation of B7H1
Increased antigen cross-presentation but impaired cross-priming after activation of peroxisome proliferator-activated receptor gamma is mediated by up-regulation of B7H1.
Specimen part
View SamplesBackground: Development of target specific therapeutics greatly benefits from simultaneous identification of biomarkers to determine aspects of bioactivity, drug safety and efficacy or even treatment outcome. This is particularly important when targeting pleiotropic factors such as the TGFbeta system. TGFbeta has become a prime target for cancer therapeutics since inhibition of TGFbeta signaling simultaneously attacks the tumor and its microenvironment. Methods: Here we introduce blood transcriptomics followed by a defined set of validation assays as a promising approach to identify novel biomarkers for monitoring TGFbeta therapy. Findings: Our initial genome-wide analysis of transcription in peripheral blood revealed 12 candidate genes specifically regulated in peripheral blood by the TGFbeta receptor I kinase inhibitor LY2109761. In subsequent in vitro and in vivo molecular and immunological analyses, the combined monitoring of gene regulation of three genes, namely TMEPAI, OCIAD2, and SMAD7 was established as novel biomarkers for anti-TGFbeta based therapies. Interpretation: Overall, the proposed algorithm of biomarker identification is easily adapted towards other drug candidates for which gene regulation can be established in peripheral blood.
Application of T cell-based transcriptomics to identify three candidate biomarkers for monitoring anti-TGFbetaR therapy.
Specimen part
View SamplesWe generated a blood-derived transcriptional signature that discriminates patients with lung cancer from non-affected smokers. When applied to blood samples from one of the largest prospective population-based cancer studies (the European Prospective Investigation into Cancer and Nutrition), this signature accurately predicted the occurrence of lung cancer in smokers within two years before the onset of clinical symptoms. Such a blood test could be used as a screening tool to enable early diagnosis of lung cancer at a curable stage.
Blood-based gene expression signatures in non-small cell lung cancer.
Specimen part
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