The clinical efficacy of EGFR kinase inhibitors gefitinib and erlotinib is limited by the development of drug resistance. The most common mechanism of drug resistance is the secondary EGFR T790M mutation. Strategies to overcome EGFR T790M mediated drug resistance include the use of mutant selective EGFR inhibitors, including WZ4002, or by the use of high concentrations of irreversible quinazoline EGFR inhibitors such as PF299804. In the current study we develop drug resistant versions of the EGFR mutant PC9 cell line which reproducibly develops EGFR T790M as a mechanism of drug resistance to gefitinib. Neither PF299804 resistant (PFR) or WZ4002 resistant (WZR) clones of PC9 harbor EGFR T790M. Instead, they demonstrate activated IGF1R signaling as a result of loss of expression of IGFBP3 and the IGF1R inhibitor, BMS 536924, restores EGFR inhibitor sensitivity. Intriguingly, prolonged exposure to either PF299804 or WZ4002 results in the emergence of a more drug resistant subclone which contains ERK activation. A MEK inhibitor, CI-1040, partially restores sensitivity to EGFR/IGF1R inhibitor combination. Moreover, an IGF1R or MEK inhibitor used in combination with either PF299804 or WZ4002 completely prevents the emergence of drug resistant clones in this model system. Our studies suggest that more effective means of inhibiting EGFR T790M will prevent the emergence of this common drug resistance mechanism in EGFR mutant NSCLC. However, multiple drug resistance mechanisms can still emerge. Preventing the emergence of drug resistance, by targeting pathways activated in resistant cancers before they emerge, may be a more effective clinical strategy.
Resistance to irreversible EGF receptor tyrosine kinase inhibitors through a multistep mechanism involving the IGF1R pathway.
Specimen part
View SamplesTo understand which genes acts downstream AtHB1 affecting hypocotyl growth in Arabidopsis thaliana, we performed transcriptional profiles of 4-day-old seedlings grown in a short-day regime comparing wild-type with athb1-1 mutant plants. These results show that some of the AtHB1-regulated genes modulate cell elongation, particularly cell wall composition and elongation, or encode proteins that serve as a source of carbon, nitrogen, and sulfur for early seedling growth. Overall design: RNA-Seq data for 4-day-old wild-type (Col-0) and athb1-1 mutant seedlings grown under short-day conditions. Biological triplicates were performed for each genotype analyzed.
Arabidopsis thaliana HomeoBox 1 (AtHB1), a Homedomain-Leucine Zipper I (HD-Zip I) transcription factor, is regulated by PHYTOCHROME-INTERACTING FACTOR 1 to promote hypocotyl elongation.
Subject
View SamplesHost defense by the innate immune system requires the establishment of antimicrobial states allowing cells to cope with microorganisms before the onset of the adaptive immune response. Interferons (IFN) are of vital importance in the establishment of cell-autonomous antimicrobial immunity. Speed is therefore an important attribute of the cellular response to IFN. With much of the antimicrobial response being installed de novo, this pertains foremost to gene expression, the rapid switch between resting-state and active-state transcription of host defense genes. Our results show how mRNA expression changes upon IFNb or IFNg treatment in wild typ and Irf9-/- bone marrow derived macrophages. Overall design: Methods: Bone marrow derived macrophage mRNA of wild-type (WT) and Irf9 knock out mice (IRF9-/-) untreated, as well as 2h IFNb and IFNg treated were generated by deep sequencing, in triplicate, using Illumina sequencing.
A molecular switch from STAT2-IRF9 to ISGF3 underlies interferon-induced gene transcription.
Specimen part, Cell line, Treatment, Subject
View SamplesHost defense by the innate immune system requires the establishment of antimicrobial states allowing cells to cope with microorganisms before the onset of the adaptive immune response. Interferons (IFN) are of vital importance in the establishment of cell-autonomous antimicrobial immunity. Speed is therefore an important attribute of the cellular response to IFN. With much of the antimicrobial response being installed de novo, this pertains foremost to gene expression, the rapid switch between resting-state and active-state transcription of host defense genes. Our results show how mRNA expression changes upon IFNb treatment in wild type and Irf9-/- mouse embryonic fibroblasts. Overall design: Methods: Mouse embryonic fibroblast (MEF) mRNA of wild-type (WT) and Irf9 knock out mice (IRF9-/-) untreated, as well as 2h IFNb treated were generated by deep sequencing, in triplicate, using Illumina sequencing.
A molecular switch from STAT2-IRF9 to ISGF3 underlies interferon-induced gene transcription.
Subject
View SamplesHost defense by the innate immune system requires the establishment of antimicrobial states allowing cells to cope with microorganisms before the onset of the adaptive immune response. Interferons (IFN) are of vital importance in the establishment of cell-autonomous antimicrobial immunity. Speed is therefore an important attribute of the cellular response to IFN. With much of the antimicrobial response being installed de novo, this pertains foremost to gene expression, the rapid switch between resting-state and active-state transcription of host defense genes. Our results show how mRNA expression changes upon IFNb treatment in wild type and Irf9-/- THP1 cells. Overall design: Methods: mRNA of untreated and IFNb treated wild-type (WT) and Irf9 knock out (IRF9-/-) human monocytic THP1 cells were analyzed by deep sequencing, in triplicate, using Illumina sequencing.
A molecular switch from STAT2-IRF9 to ISGF3 underlies interferon-induced gene transcription.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reactivation of ERK signaling causes resistance to EGFR kinase inhibitors.
Cell line
View SamplesThe clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials.
Reactivation of ERK signaling causes resistance to EGFR kinase inhibitors.
Cell line
View SamplesOBJECTIVE: Systemic sclerosis (SSc)-related interstitial lung disease (ILD) is one of the leading causes of mortality. We undertook this study to analyze the gene expression of lung tissue in a prospective cohort of patients with SSc-related ILD and to compare it with that in control lungs and with 2 prospective clinical parameters in order to understand the molecular pathways implicated in progressive lung disease. METHODS: Lung tissue was obtained by open lung biopsy in 28 consecutive patients with SSc-related ILD and in 4 controls. High-resolution computed tomography (HRCT) and pulmonary function testing (PFT) were performed at baseline and 2-3 years after treatment based on lung histologic classification. Microarray analysis was performed, and the results were correlated with changes in the HRCT score (FibMax) and PFT values. Quantitative polymerase chain reaction (qPCR) and immunohistochemistry were used to confirm differential levels of messenger RNA and protein. RESULTS: Lung microarray data distinguished patients with SSc-related ILD from healthy controls. In the lungs of patients with SSc-related ILD who had nonspecific interstitial pneumonia (NSIP), expressed genes included macrophage markers, chemokines, collagen, and transforming growth factor (TGF)- and interferon (IFN)-regulated genes. Expression of these genes correlated with progressive lung fibrosis defined by the change in FibMax. Immunohistochemistry confirmed increased markers of collagen (COL1A1), IFN (OAS1 and IFI44), and macrophages (CCL18 and CD163), and the positive correlation with the change in FibMax was confirmed by qPCR in a larger group of SSc patients with NSIP. Several genes correlated with both the change in FibMax (r > 0.4) and the change in % predicted forced vital capacity (r < -0.1), including IFN and macrophage markers, chemokines, and heat-shock proteins. CONCLUSION: These results highlight major pathogenic pathways relevant to progressive pulmonary fibrosis in SSc-related ILD: macrophage emigration and activation, and up-regulated expression of TGF- and IFN-regulated genes
Association of Interferon- and transforming growth factor β-regulated genes and macrophage activation with systemic sclerosis-related progressive lung fibrosis.
Specimen part, Disease, Disease stage, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Lamin B1 depletion in senescent cells triggers large-scale changes in gene expression and the chromatin landscape.
Specimen part, Cell line
View SamplesIn almost every countries the proportion of people over 60 years is growing faster that any other age group. Increased life expectancy is leading to the characterization of specific aspects of aging for the various physiological systems. The study of healthy aging is important to design strategies capable to maximize the health and to prevent chronic diseases in older people. Immunosenscence reflects the age-related changes of the immune system and the reduced capacity of elderly people to cope with new infections. To elucidate changes in gene expression related to systemic aging and immunosenescence in an unbiased manner we performed comparative microarray analysis on whole blood cell from healthy middle-aged versus elderly men, and correlated results with functional measurements of aerobic capacity. Blood cells from elderly subjects showed age-related changes in the expression of several markers of immunosenescence, inflammation and oxidative stress, and showed impairments in metabolic and biosynthetic capacities.
Aging: a portrait from gene expression profile in blood cells.
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