Project description:To compare the cell signaling events between PC-3 cells and MDA-MB-468 cells, we performed a Reverse Phase of Protein Array (RPPA) profiling on 468 and PC-3 Cells that treated with DMSO, AZD5363, MS21 at 1µM for 24hr respectively.
Project description:11 BRAF inhibitor resistance melanoma cells were treated with PAK inhibitor PF3758309 for 48 hr, the cell lysis were analyzed by RPPA profiling by protein array (RPPA)
Project description:3 BRAF/MEK inhibitor resistance melanoma cells were treated with PAK inhibitor PF3758309 for 48 hr, the cell lysis were analyzed by RPPA profiling by protein array (RPPA)
Project description:Aberrant activation of PI3K pathway is frequently observed in triple negative breast cancer (TNBC). However single agent PI3K inhibitors have shown limited anti-tumor activity. To investigate biomarkers of response and resistance mechanisms, we tested 17 TNBC patient-derived xenograft (PDX) models representing diverse genomic backgrounds and varying degrees of PI3K pathway signaling activities for their tumor growth response to the pan-PI3K inhibitor BKM120. Baseline and post-treatment PDX tumors harvested following 3 days of BKM120 or vehicle administration were subjected to reverse phase protein array (RPPA) to identify protein markers associated with tumor growth response. While BKM120 consistently reduced PI3K pathway activity, as demonstrated by reduced levels of phosphorylated AKT, percentage tumor growth inhibition (%TGI) ranged from 35% in the least sensitive to 84% in the most sensitive PDX model at the completion of approximately 3-4 weeks of treatment. Several biomarkers showed significant association with resistance, including elevated baseline levels of growth factor receptors (EGFR, pHER3 Y1197), PI3Kp85 regulatory subunit, anti-apoptotic protein BclXL, EMT (Vimentin, MMP9, IntegrinaV), NFKB pathway (IkappaB, RANKL), and intracellular signaling molecules including Caveolin, CBP, and KLF4, as well as treatment-induced increase in the levels of phosphorylated forms of Aurora kinases. Sensitivity to BKM120 was associated with higher baseline levels of proapoptotic markers (Bak and Caspase 3) and a greater number of markers differentially changed following BKM120 therapy. Interestingly, markers indicating PI3K pathway signaling activation or PTEN loss at baseline were not significantly correlated to %TGI. These results provide important insights into biomarker development for PI3K inhibitors in TNBC.
Project description:The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only examine efficacy of a therapy across a population, but also study crucial aspects of cancer biology in response to treatment. Herein we describe the development and characterization of an ovarian-PDX model in order to study the development of chemoresistance. We demonstrate that PDX tumors are not simply composed of tumor-initiating cells, but recapitulate the original tumor’s heterogeneity, oncogene expression profiles, and clinical response to chemotherapy. Combined carboplatin/paclitaxel treatment of PDX tumors enriches the cancer stem cell populations, but persistent tumors are not entirely composed of these populations. RNA-Seq analysis of treated PDX tumors compared to untreated tumors demonstrates a consistently contrasting genetic profile after therapy, suggesting similar, but few, pathways are mediating chemoresistance. The pathways most significantly altered included Protein Kinase A signaling, GNRH signaling, and sphingosine-1-phosphate signaling. Pathways and genes identified by this methodology represent novel approaches to targeting the chemoresistant population in ovarian cancer 6 pairs of Patient-Derived Xenografts (PDX) were ananlyzed using RNA-seq for a total of 12 samples. Each pair consists of a treated and untreated PDX of ovarian cancer. Treated Ovarian cancer PDXs were treated with 4 weeks of a combination of carboplatin and taxol. RNA was isolated and converted to cDNA. RNA-seq was conductred on the Illumina HiSeq 2000 with 50 bp paired end sequencing
Project description:To investigate the novel functions of PTEN-L, we performed a Reverse Phase of Protein Array (RPPA) profiling on 468.Ctrl, 468.PTEN, and 468.PTEN-L sublines to compare cell signaling events between PTEN expression
Project description:Phosphoinositide 3-kinase (PI3K) signaling activation is frequently observed in triple negative breast cancer, however, PI3K inhibitors have shown limited clinical activity. To investigate resistance mechanisms, we performed global transcriptome, proteome, phosphoproteome and kinome analysis of a panel of triple negative breast cancer patient derived xenograft models with varying responsiveness to buparlisib, a pan-PI3K inhibitor, for differentially expressed baseline and post-treatment biomarkers. Resistance was associated with incomplete inhibition of PI3K and upregulated MAPK/MEK signaling in response to buparlisib. Outlier phosphoproteome and kinome analyses identified additional candidates in association with buparlisib resistance, including NEK9 and MAP2K4. Knockdown of NEK9 or MAPK2K4 reduced both baseline and feedback MAPK/MEK signaling and enhanced buparlisib efficacy in vitro. Interestingly, we show that a complex ins/del in PIK3CA led to a change in buparlisib response in a NEK9/MAP2K4 dependent manner. In summary, our study indicates a role for NEK9 and MAP2K4 in mediating buparlisib resistance and demonstrates the value of unbiased global analyses in uncovering resistance mechanisms to targeted therapy.
Project description:We have generated a collection of patient-derived xenograft (PDX) tumor models and characterized them at the molecular level to facilitate precision oncology. Surgically resected HCC specimens were subcutaneously implanted in immunodeficient mice. Resulting xenografts were serially implanted to establish transplantable PDX models, which were sequentially subject to whole exome sequencing (WES), gene expression array, genome-wide human single nucleotide polymorphism (SNP) array 6.0, and serum a–fetoprotein (AFP) detection assay. The feasibility as a preclinical model was validated by efficacy studies using a standard-of-care (SOC) and a targeted agent, respectively.
