Project description:Treatment of established lines and primary ovarian cancer cultures with Src and MEK inhibitors, saracatinib and selumetinib, respectively, showed target kinase inhibition and synergistic induction of apoptosis and cell cycle arrest in vitro and tumor inhibition in xenografts.
Project description:We identified IGF2BP1 as a marker of the C5 molecular subtype of high-grade ovarian carcinoma (HG-SOC). IGF2BP1 promotes SRC activity and ERK2 expression enhancing the tolerance towards SRC- and MEK-directed inhibitors saracatinib and selumetib. Combination treatment overcomes IGF2BP1-promoted resistance.
Project description:A major component of the cardiac stress response is the simultaneous activation of several gene regulatory networks. Interestingly, the transcriptional regulator steroid receptor coactivator-2, SRC-2 is often decreased during cardiac failure in humans. We postulated that SRC-2 suppression plays a mechanistic role in the stress response and that SRC-2 activity is an important regulator of the adult heart gene expression profile. Genome-wide microarray analysis, confirmed with targeted gene expression analyses revealed that genetic ablation of SRC-2 activates the “fetal gene program” in adult mice as manifested by shifts in expression of a) metabolic and b) sarcomeric genes, as well as associated modulating transcription factors. While these gene expression changes were not accompanied by changes in left ventricular weight or cardiac function, imposition of transverse aortic constriction (TAC) predisposed SRC-2 knockout (KO) mice to stress-induced cardiac dysfunction. In addition, SRC-2 KO mice lacked the normal ventricular hypertrophic response as indicated through heart weight, left ventricular wall thickness, and blunted molecular signaling known to activate hypertrophy. Our results indicate that SRC-2 is involved in maintenance of the steady-state adult heart transcriptional profile, with its ablation inducing transcriptional changes that mimic a stressed heart. These results further suggest that SRC-2 deletion interferes with the timing and integration needed to respond efficiently to stress through disruption of metabolic and sarcomeric gene expression and hypertrophic signaling, the three key stress responsive pathways.
Project description:A major component of the cardiac stress response is the simultaneous activation of several gene regulatory networks. Interestingly, the transcriptional regulator steroid receptor coactivator-2, SRC-2 is often decreased during cardiac failure in humans. We postulated that SRC-2 suppression plays a mechanistic role in the stress response and that SRC-2 activity is an important regulator of the adult heart gene expression profile. Genome-wide microarray analysis, confirmed with targeted gene expression analyses revealed that genetic ablation of SRC-2 activates the M-bM-^@M-^\fetal gene programM-bM-^@M-^] in adult mice as manifested by shifts in expression of a) metabolic and b) sarcomeric genes, as well as associated modulating transcription factors. While these gene expression changes were not accompanied by changes in left ventricular weight or cardiac function, imposition of transverse aortic constriction (TAC) predisposed SRC-2 knockout (KO) mice to stress-induced cardiac dysfunction. In addition, SRC-2 KO mice lacked the normal ventricular hypertrophic response as indicated through heart weight, left ventricular wall thickness, and blunted molecular signaling known to activate hypertrophy. Our results indicate that SRC-2 is involved in maintenance of the steady-state adult heart transcriptional profile, with its ablation inducing transcriptional changes that mimic a stressed heart. These results further suggest that SRC-2 deletion interferes with the timing and integration needed to respond efficiently to stress through disruption of metabolic and sarcomeric gene expression and hypertrophic signaling, the three key stress responsive pathways. For microarray analysis, 250ng of RNA isolated from total heart (RNeasy kit, Qiagen) for each sample was labeled using the new standard Affymetrix linear amplification protocol using the 3' IVT Express Kit. This was reverse-transcribed and cRNA was produced and biotinylated via in vitro transcription. A hybridization cocktail containing Affymetrix spike-in controls and 15 M-NM-<g fragmented, labeled cRNA was loaded onto a GeneChipM-BM-. Mouse 430 2.0 array. The array was hybridized for 16 hours at 45M-BM-0C with rotation at 60 rpm then washed and stained with a strepavidin, R-phycoerythrin conjugate stain using the FS 450_0001 Fluidics protocol setting. Signal amplification was done using biotinylated antistreptavidin. The stained array was scanned on the Affymetrix GeneChipM-BM-. Scanner 3000. The images were analyzed and quality control metrics recorded using Affymetrix Command Console v3. Experiments were run using Affymetrix MG 430 2.0 chip with 45,101 probesets representing 20,757 unique genes. There were 8 experiments in 2 groups: WT-unstressed M-bM-^@M-^S 4 experiments, and KO-unstressed M-bM-^@M-^S 4 experiments. QC parameters for all experiments were within the acceptable limits. We used the following software packages for data QC, statistical analysis and presentation of the results: Affymetrix Expression Console (www.affymetrix.com), Partek (www.partek.com), BRB Array Tools (linus.nci.nih.gov/BRB-ArrayTools.html), and dChip (biosun1.harvard.edu/complab/dchip). Expressions were estimated using the RMA (Multi-Array Analysis) method [38] with Partek software. Differentially expressed genes were found using the RVM (Random Variance Model) t-test, which is designed for small sample size experiments [39]. We used BRB Array Tools software, developed by Dr. Richard Simon and the BRB-ArrayTools Development Team. All genes were included in the comparison. For the genes represented by more than one probeset, we used the most highly expressed probeset. The cutoffs for differentially expressed genes were False Discovery Rate (FDR) = 0.05 [40].
Project description:Pre-cancerous metaplasia progression to dysplasiasignificantlyincreases the risk of gastriccancer, and effective targeting strategies forpre-cancerouslesions are currently lacking.Weaimed to identify key signaling pathways critical for stem cell survival and function in dysplasia.Usingmouse and humanmetaplastic and dysplastic organoids, we evaluated responsestoPyrvinium, a putative anti-cancer drug.WhilePyrvinium induced growth arrest in metaplasticorganoids, itinducedcell death in dysplastic organoidsthrough a dual blockade of MEK/ERKand STAT3 signaling pathways. Pyrvinium specifically targeted stem cells andproliferating cellsin dysplastic organoids.Pyrviniumarrestedmetaplasia progression andpromoted repopulationof themousestomach mucosawith normal lineages.Furthermore, Pyrvinium exhibitedsuppressive effects on the growth and survival of human organoids with dysplastic features, through simultaneous blockingthe MEK/ERK and STAT3 signaling pathways.Therefore, ourfindings suggest that Pyrvinium is a promising therapeutic agent for reprogramming the pre-cancerous milieu to prevent of gastric cancer development.
Project description:The restoration of catalytic activity to mutant enzymes by small molecules is well-established for in vitro systems. Here we show that the protein tyrosine kinase Src R388A mutant can be rescued in live cells using the small molecule imidazole. Cellular rescue of a v-Src homolog was rapid and reversible and conferred predicted oncogenic properties. Using chemical rescue in combination with mass spectrometry, six known Src kinase substrates were confirmed, and several new protein targets identified. Chemical rescue data suggests that c-Src is active under basal conditions. Rescue of R388A c-Src also allowed contributions of Src to the MAP kinase pathway to be clarified. This chemical rescue approach is likely to be of broad utility in cell signaling. We were also interested in examining the impact of Src rescue on the kinetics of gene expression. Chronic gene expression changes in v-Src transformed colon cancer and NIH3T3 cells have been reported, but the chemical rescue method permits insights into rapid kinetic changes. We used gene microarray analysis of imidazole activated Src, 1 h after imidazole treatment of 8A7F cells as well as 6N7F control cells, a set of several genes show increases (>1.7-fold) at 1 h in the 8A7F cells and another set show decreases (>1.7-fold) at 1 h with minimal changes in 6N7F control cells. Thirteen of these genes were further analyzed using real-time RT-PCR and most of the genes tested showed similar changes using both techniques. These gene changes were not reported in cells chronically transformed with v-Src or rapidly stimulated with growth factors suggesting that rapid initiation of Src-mediated tyrosine phosphorylation may induce a specialized pattern of gene expression changes. However, these earlier experiments were done under different conditions which may also contribute to gene effects. Keywords: time course, cell type comparison
Project description:RNA sequencing was carried out to identify the signaling pathways and hallmarks that change following MEK and/or JAK/STAT3 pathway inhibition.
Project description:This study contains 4 exomes of A375, parental, BRAF resistant population, MEK resistant population and a BRAF/MEK resistant population