Melanoma resistant to MAPK inhibitors (MAPKi) displays loss of fitness upon experimental MAPKi withdrawal and, clinically, may be resensitized to MAPKi therapy after a drug holiday. Here, we uncovered and therapeutically exploited the mechanisms of MAPKi addiction in MAPKi-resistant BRAF MUT or NRAS MUT melanoma. MAPKi-addiction phenotypes evident upon drug withdrawal spanned transient cell-cycle slowdown to cell-death responses, the latter of which required a robust phosphorylated ERK (pERK) rebound. Generally, drug withdrawal–induced pERK rebound upregulated p38–FRA1–JUNB–CDKN1A and downregulated proliferation, but only a robust pERK rebound resulted in DNA damage and parthanatos-related cell death. Importantly, pharmacologically impairing DNA damage repair during MAPKi withdrawal augmented MAPKi addiction across the board by converting a cell-cycle deceleration to a caspase-dependent cell-death response or by furthering parthanatos related cell death. Specifically in MEKi-resistant NRAS MUT or atypical BRAF MUT melanoma, treatment with a type I RAF inhibitor intensified pERK rebound elicited by MEKi withdrawal, thereby promoting a cell death–predominant MAPKi-addiction phenotype. Thus, MAPKi discontinuation upon disease progression should be coupled with specific strategies that augment MAPKi addiction. Overall design: BRAF/MEK inhibitors resistant cell lines M249DDR5 and SKMEL28DDR1 were assayed for their responses after 6 hr of BRAF/MEK inhibitor treatment and after inhibitors withdrawal (by washin) for 6 and 24 hours
Exploiting Drug Addiction Mechanisms to Select against MAPKi-Resistant Melanoma.
Cell line, Subject
View SamplesTo determine how aging impacts gene expression in hematopoietic stem cells (HSCs), human CD34+ cells from bone marrow (34BM) and mobilized stem cell products (34P38NPBSC) were examined using microarray-based expression profiling. Differential expression changes were confirmed by microarray comparisons of younger and older expanded T-cell populations.
Decreased IRF8 expression found in aging hematopoietic progenitor/stem cells.
No sample metadata fields
View SamplesRNAseq to determine baseline expression of kinome in MDA-MB-231 claudin-low breast cancer cell line
Dynamic reprogramming of the kinome in response to targeted MEK inhibition in triple-negative breast cancer.
No sample metadata fields
View SamplesRNAseq of SUM159PT claudin-low breast cancer cell line to determine baseline kinome expression
Dynamic reprogramming of the kinome in response to targeted MEK inhibition in triple-negative breast cancer.
No sample metadata fields
View SamplesImmune checkpoint blockade has shown tremendous anti-tumor potential in the clinic. However, these therapies are only effective in a subset of patients, so identification of additional immunomodulatory molecules that enhance the anti-tumor activity of these treatments may expand their clinical utility. In particular, identifying small molecules that complement existing immunotherapies has been relatively unexplored, so we performed a small molecule screen to identify compounds that can enhance co-inhibitory molecule blockade, to improve the anti-tumor adaptive immune response. Our unbiased screen identified inhibitors of cyclin-dependent kinase 4 and 6 (CDK4/6), including the FDA-approved palbociclib, as a class of small molecule compounds that exhibited significant immunostimulatory activity in vitro. In accordance with our in vitro finding of enhanced NFAT signaling, single-cell RNA-sequencing confirmed that in vivo exposure to CDK4/6 inhibitors enhanced NFAT signaling in tumor infiltrating T cells. Moreover, our results revealed that CDK4/6 inhibition up-regulated activation molecules and down-regulated suppressive molecules in these cells. CDK4/6 inhibition also increased the number of T cells with activated TCR (T cell receptor) signaling, as well as factors that are important for signal transduction downstream of TCR signaling. In summary, the impact of CDK4/6i on cell cycle progression and T cell proliferation are balanced favorably towards increased T cell recruitment and enhanced effector cell function, mediated in part by activation of the NFAT family of transcription factors. Further, our results demonstrate that CDK4/6i enhances PD-1 blockade through increased T-cell effector function and inhibition of immune suppressive cytokine production. While prolonged CDK4/6i treatment could be immunosuppressive due to adverse effects on lymphocyte proliferation, properly timed/sequenced CDK4/6i may potentiate the clinical impact of anti-PD-1/PD-L1 antibodies. As palbociclib is FDA-approved and multiple other CDK4/6 inhibitors are in clinical trials, we expect that this hypothesis will undergo rapid testing in humans. Overall design: Single-cell comparison of control and CDK4/6 inhibitor treated tumor infiltrating T cells
CDK4/6 Inhibition Augments Antitumor Immunity by Enhancing T-cell Activation.
Specimen part, Cell line, Subject
View SamplesPURPOSE: To examine if a parental high fat diet (HFD) influences metabolic health in two generations of offspring, and alters the germ cell (GC) transcriptome. PROCEDURE: GC-eGFP Sprague Dawley rats were weaned onto HFD (45% fat) or Control Diet (CD; 10% fat). After metabolic testing, founders (F0) were bred with controls, establishing the F1 generation. Germ cells from F0 males were isolated and their RNA sequenced. F1 rats were bred with control rats at 17 weeks to generate F2 offspring. FINDINGS: HFD resulted in 9.7% and 14.7% increased weight in male and female F0 respectively. F1 offspring of HFD mothers were heavier than controls. F1 daughters of HFD-fed males were also heavier. F2 male offspring derived from HFD-fed maternal grandfathers were 7.2% heavier, and exhibited increases of 31% in adiposity, 97% in plasma leptin and 300% in luteinising hormone to testosterone ratio. HFD exposure did not alter the F0 GC transcriptome. CONTROLS: Matched CD was consumed by all animals not consuming the HFD. Animals were compared to a parallel cohort of CD rats. CONCLUSIONS: HFD consumption by maternal grandfathers results in a disrupted metabolic phenotype in grandsons. This effect is not mediated by alterations to the GC transcriptome. Overall design: Male rats high fat diet vs. control diet. 4 replicates per condition. SmallRNA seq and mRNAseq for each replicate and condition
High-fat diet disrupts metabolism in two generations of rats in a parent-of-origin specific manner.
No sample metadata fields
View SamplesSince normal brain function depends upon continuous oxygen delivery and short periods of hypoxia can precondition against subsequent ischemia, this study examined the effects of brief hypoxia on the whole genome transcriptional response in adult mouse brain.
Regional genome transcriptional response of adult mouse brain to hypoxia.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesThe overall goal of this project is to investigate the contribution of the inferior alveolar nerve (IAN) towards cellular mechanisms required for regeneration of the murine incisor. Here, we conducted gene expression profiling of adult murine incisor dental mesenchyme tissue following two weeks after unilateral resection of the IAN from both the denerved and contralateral incisor of five wild-type mice.
Secretion of shh by a neurovascular bundle niche supports mesenchymal stem cell homeostasis in the adult mouse incisor.
Sex, Specimen part
View SamplesResponse of A549 cells treated with Aspergillus fumigatus wild type germinating conidia (WT_GC) or PrtT protease deficient mutant conidia (PrtT-GC) or inert acrylic 2-4 micron beads (Beads) for 8h
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View Samples