Project description:MEL02-1 and MEL02-2 are melanoma cell lines derived from a melanoma patient. MEL02-1 was established from a pre-treatment metastatic lesion. MEL02-2 was established from post-treatment regressing lesion.
Project description:Blocking the PD-1/PD-L1 immunosuppressive pathway has shown promise in the treatment of certain cancers including melanoma. This study investigates differences in the gene expression profiles of human melanomas that do or do not display the immunosuppressive protein PD-L1. Further understanding of genes expressed within the tumor microenvironment of PD-L1+ tumors may lead to improved rationally designed treatments. Gene expression profiling was performed on total RNA extracted by laser capture microdissection from 11 archived formalin-fixed paraffin-embedded (FFPE) melanoma specimens, 5 of which were PD-L1 positive and 6 PD-L1 negative. Details of the design, and the gene signatures found are given in the paper associated with this GEO Series: Janis M. Taube, Geoffrey D. Young, Tracee L. McMiller, Shuming Chen, January T. Salas, Theresa S. Pritchard, Haiying Xu, Alan K. Meeker, Jinshui Fan, Chris Cheadle, Alan E. Berger, Drew M. Pardoll, and Suzanne L. Topalian, Differential expression of immune-regulatory genes associated with PD-L1 display in melanoma: implications for PD-1 pathway blockade, Clin Cancer Res 2015, in press.
Project description:Treatment of advanced V600BRAF mutant melanoma using a BRAF inhibitor (BRAFi) or its combination with a MEKi typically elicits partial responses. We compared the transcriptomes of patient-derived tumors regressing on MAPKi therapy against MAPKi-induced temporal transcriptomic states in human melanoma cell lines or murine melanoma in immune-competent mice. Despite heterogeneous dynamics of clinical tumor regression, residual tumors displayed highly recurrent transcriptomic alterations and enriched processes, which were also observed in MAPKi-selected cell lines (implying tumor cell-intrinsic reprogramming) or in bulk mouse tumors (and the CD45-negative or -positive fractions,, implying tumor cell-intrinsic or stromal/immune alterations, respectively). Tumor cell-intrinsic reprogramming attenuated MAPK-dependency, while enhancing mesenchymal, angiogenic and IFN-inflammatory features and growth/survival dependence on multi-RTKs and PD-L2. In the immune compartment, PD-L2 upregulation in CD11c+ immunocytes drove the loss of T-cell inflammation and promoted BRAFi resistance. Thus, residual melanoma early on MAPKi therapy already displays potentially exploitable adaptive transcriptomic, epigenomic, immune-regulomic alterations.
Project description:Lack of a standard method for stratifying advanced-stage NSCLC patients receiving platinum combination therapy often results in a number of patients that do not derive benefit yet are still exposed to treatment toxicity. We hypothesized that miRNAs in pre-treatment serum and/or plasma could be used to differentiate non-small cell lung cancer (NSCLC) patients who would have disease progression to first-line carboplatin and gemcitabine chemotherapy at first response assessment. miRNA profiling of mature and precursor miRNAs was performed on total RNA isolated from the pre-treatment serum and plasma of 24 NSCLC patients. Single validated candidates or combinations thereof were selected based on specificity and sensitivity to segregate patients with disease progression at first radiologic response (PD) vs. those without progressed disease (nonPD). Two precursor miRNA were significantly over-expressed in serum (but not plasma) of PD patients: pre-miR-518b and pre-miR-598. Serum miRNAs may serve as a screening tool in predicting chemoresistance to platinum-based combination chemotherapy. miRNA microarray was performed on RNA extracted from matched human serum or plasma obtained from NSCLC patients
Project description:Thirty-eight tumors from 17 patients treated with BRAF inhibitor (n=12) or combination BRAF/MEK inhibitors (n=5) with known PD-L1 expression were analyzed. RNA expression arrays were performed on all pre-treatment (PRE, n=17), early during treatment (EDT, n=8) and progression (PROG, n=13) biopsies. HLA-A/HLA-DPB1 expression was assessed by immunohistochemistry (IHC). Gene set enrichment analysis (GSEA) of PRE, EDT and PROG melanomas revealed that transcriptome signatures indicative of immune cell activation were strongly positively correlated with PD-L1 staining. In contrast, MAPK signaling and canonical Wnt/-ß-catenin activity were negatively associated with PD-L1 melanoma expression. The expression of PD-L1 and immune activation signatures did not simply reflect the degree or type of immune cell infiltration, and was not sufficient for tumor response to MAPK inhibition.
Project description:Parkinson's disease (PD) is a prevalent, multifaceted neurodegenerative disease caused by mostly unknown factors. MicroRNAs (miRNAs) are small (~21 nucleotides long) RNAs that regulate up to hundreds of target genes. To study the role of miRNAs in PD and following surgical brain electrical stimulation treatment response, the expression profiling of miRNAs in peripheral blood leukocyte cells of PD patients pre- deep brain stimulation (DBS) and post-DBS both on electrical stimulation, and following a short one-hour electrical stimulation cessation, as well as of healthy control volunteers, were examined.
Project description:PD-1 immune checkpoint blockade provides significant clinical benefits for cancer patients. However, factors influencing innate sensitivity remain incompletely catalogued. We analyzed the somatic mutanomes and transcriptomes of pretreatment melanoma biopsies. Mutations in cell adhesion genes and the DNA repair gene BRCA2 were enriched in responding tumors, and a high mutational load associated with improved survival. Innately resistant tumors displayed frequent transcriptomic up-expression of genes that enriched for mesenchymal transition, cell adhesion, ECM organization, wound-healing and angiogenesis. The transcriptomes of innate resistance also enriched for signatures indicating up-regulation of these processes. Notably, MAPK-targeted therapy (MAPKi) induced similar signatures in melanoma, suggesting that a form of MAPKi resistance mediates cross-resistance to anti-PD-1 therapy. Co-enrichment of IPRIM (Innate anti-PD-1 Resistance Induced by MAPKi) signatures defined a transcriptomic subset across advanced cancers, suggesting that attenuating processes underlying these signatures may augment anti-PD1 responses. Thus, multi-factorial determinants influence anti-PD-1 patterns in melanoma.
Project description:To identify which E3 ligases ubiquitinate PD-L1, we overexpressed PD-L1-Flag in HEK293 cells and used anti-Flag magnetic beads to pull down PD-L1 from cell lysates. The interacting proteins were then analyzed by mass spectrometry, revealing that three E3 ligases interact with PD-L1.
Project description:Parkinson’s disease (PD) is the second most common neurodegenerative disease worldwide and the first involving motor symptoms. Deep brain stimulation (DBS) neurosurgery treatment through electrodes implanted to the subthalamic nucleus (STN) improves dramatically the debilitating motor symptoms of the disease due to yet unknown molecular mechanisms. Affymetrix human junction prototype microarrays (HJAY) of blood leukocytes mRNA from PD patients prior to, and following DBS neurosurgery treatment on electrical stimulation were compared to these of age- and gender-matched healthy control volunteers. About 95% of all human genes undergo alternative splicing, and alternative splicing is involved in human diseases and specifically in neurodegenerative diseases. Thus, the goal of this study was to detect alternatively spliced genes in PD patients prior to, and following DBS and to predict the effect of these on the functional level of change at the transcript level (such as exon inclusion, intron retention and nonsense-mediated decay events). Understanding the role of alternative splicing in neurodegenerative diseases will open new avenues to future novel approaches for early detection and neuroprotective treatment enabled by the development of future genetic therapeutics targeted at specific modified splice variants. A total of 11 blood leukocytes mRNA samples were analyzed: four from Parkinson's Disease (PD) patients pre-DBS treatment, three from PD patients tested again post-DBS (while being on electrical stimulation), three from age- and gender-matching healthy control (HC) volunteers, and one PD sample pre-DBS sample was re-stained and rescanned .
Project description:<p>Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by dense fibrous stroma, resistance to chemotherapy and a lack of actionable driver mutations, but is highly associated with ultraviolet light DNA damage. We analysed 60 patients with advanced DM treated with programmed cell death 1 (PD-1) or PD-1 ligand (PD-L1) blocking antibody therapy. Objective tumor responses were observed in 42 of the 60 patients (70%, 95% confidence interval 57-81%), including 19 patients (32% overall) with a complete response. Whole-exome sequencing revealed a high mutational load and frequent NF-1 mutations (14 out of 17 cases). Immunohistochemistry (IHC) analysis from 19 DM and 13 non-DM revealed a higher percentage of PD-L1 positive cells in the tumor parenchyma in DM (p = 0.04), highly associated with increased CD8 density and PD-L1 expression in the tumor invasive margin. Therefore, patients with advanced DM derive significant clinical benefit from PD-1/PD-L1 immune checkpoint blockade therapy despite being a cancer defined by its dense desmoplastic fibrous stroma. The benefit is likely derived from the high mutational burden and a frequent pre-existing adaptive immune response limited by PD-L1 expression.</p>