Project description:Although membrane-anchored Pd-l1 has been well-studied for its engagement with PD-1 on T cells to evade anti-tumor immunity, whether Pd-l1 regulate oncogenic signaling pathways in tumor cells remains elusive. In this experiment, to further dissect roles of the K262 residue acetylation for Pd-l1 nuclear function, we profiled RNA expression of WT or K262Q mutant mouse Pd-l1 re-expressed in CT26 KO Pd-l1 cells. Methods: Total RNA fromCT26/Vector, CT26/WT or CT26 Pd-l1 KO cells was purified using Qiagen RNeasy mini kit (Qiagen) according to the manufacturer’s instructions. Library preparation and sequenceing analysis were performed by BGI-Hong Kong Co. Ltd. Conclusions: Our study indicates that Pd-l1 acetylation modification may affect its function in nuclear.
Project description:Although membrane-anchored PD-L1 has been well-studied for its engagement with PD-1 on T cells to evade anti-tumor immunity, whether PD-L1 regulate oncogenic signaling pathways in tumor cells remains elusive. Methods: Total RNA from MDA-MB-231 wild type (WT) , MDA-MB-231 PD-L1 knock-out (KO), CT26 WT or CT26 Pd-l1 KO cells was purified using Qiagen RNeasy mini kit (Qiagen) according to the manufacturer’s instructions. Library preparation and sequenceing analysis were performed at the Molecular Genetics Core facility in Dana-Farber Cancer institute. RNA-seq data was aligned using STAR v2.5.4a. Conclusions: Our study indicates that PD-L1 may regulate genes that are involved in immune response regulating pathways.
Project description:Since both endogenous synthesis in tumor cells and bacterial sulfur reduction activities are sources of H2S in colon cancer microenvironment, in addition to using CBS -/+ mice, we also investigated the roles of reducing H2S through adopting a sulfur amino acid restriction diet (SARD) (0.15% methionine and 0% cystine) on immunotherapy (anti-PD-L1) of colon cancer. Tumor bulk sequencing was performed in cecum orthotopic CT26 tumors collected from IgG and anti-PD-L1 treated mice both receiving normal diet and SARD.
Project description:The ability to modulate immune-inhibitory pathways using checkpoint blockade antibodies such as PD-1, PD-L1, and CTLA-4 represents a significant breakthrough in cancer therapy in recent years. This has driven interest in identifying small-molecule-immunotherapy combinations to increase the proportion of responses. Murine syngeneic models, which have a functional immune system, represent an essential tool for pre-clinical evaluation of new immunotherapies. However, immune response varies widely between models and the translational relevance of each model is not fully understood, making selection of an appropriate pre-clinical model for drug target validation challenging. Utilizing RNAseq transcriptomic profiling, we have characterised the changes in gene regulatory pathways and immune populations in CT26 mice after treatment with the combination of anti-PD-L1 and anti-CTLA-4 antibodies. At day 7 post tumor implant, the pathways analysis of differentially expressed genes indicated an enrichment for migration of leukocytes in response to inflammation and communication between innate and adaptive immune cells. Similarly, analysis of upstream regulators suggested that lipopolysaccharide, IL-1B, TNF, IFNG, and NFKB1A pathways associated with inflammation were activated. At day 14, pathways related T-helper cell signalling pathways were upregulated. In addition, upstream regulators of the lipopolysaccharide and IFNG pathway, as well STAT1 and IL21 pathway were enriched, indicative of innate and adaptive immune response to inflammation.
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:Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Tumor cell lysis by CTLs was attenuated when PD-L1 on tumor cells was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. Gene expression profile of mouse CTLs caused by PD-L1-overexpressing ovarian cancer was related to human CTLs exhaustion. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination. Genome-wide transcriptional changes in OT-1 mouse CD8+ T cells that were co-incubated with OVA peptide-loaded ID8 mouse ovarian cancer cell lines. CTLs from 4 mice were devided into 2 groups, and co-incubated with PD-L1-overexpressed ID8 or PD-L1-depleted ID8.
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.
Project description:PD-L1 Inhibitor Regulates the miR-33a-5p/PTEN Signaling Pathway and Can Be Targeted to Sensitize Glioblastomas to Radiation. Glioblastoma (GBM) is the most common and lethal brain tumor in adults. Ionizing radiation (IR) is a standard treatment for GBM patients and results in DNA damage. However, the clinical efficacy of IR is limited due to therapeutic resistance. The programmed death ligand 1 (PD-L1) blockade has a shown the potential to increase the efficacy of radiotherapy by inhibiting DNA damage and repair responses. The miR-33a-5p is an essential microRNA that promotes GBM growth and self-renewal. In this study, we investigated whether a PD-L1 inhibitor (a small molecule inhibitor) exerted radio-sensitive effects to impart an anti-tumor function in GBM cells by modulating miR-33a-5p. U87 MG cells and U251 cells were pretreated with PD-L1 inhibitor. The PD-L1 inhibitor-induced radio-sensitivity in these cells was assessed by assaying cellular apoptosis, clonogenic survival assays, and migration. TargetScan and luciferase assay showed that miR-33a-5p targeted the phosphatase and tensin homolog (PTEN) 3' untranslated region. The expression level of PTEN was measured by western blotting, and was also silenced using small interfering RNAs. The levels of DNA damage following radiation was measured by the presence of γ-H2AX foci, cell cycle, and the mRNA of the DNA damage-related genes, BRCA1, NBS1, RAD50, and MRE11. Our results demonstrated that the PD-L1 inhibitor significantly decreased the expression of the target gene, miR-33a-5p. In addition, pretreatment of U87 MG and U251 cells with the PD-L1 inhibitor increased radio-sensitivity, as indicated by increased apoptosis, while decreased survival and migration of GBM cells. Mir-33a-5p overexpression or silencing PTEN in U87 MG and U251 cells significantly attenuated PD-L1 radiosensitive effect. Additionally, PD-L1 inhibitor treatment suppressed the expression of the DNA damage response-related genes, BRCA1, NBS1, RAD50, and MRE11. Our results demonstrated a novel role for the PD-L1 inhibitor in inducing radio- sensitivity in GBM cells, where inhibiting miR-33a-5p, leading to PTEN activated, and inducing DNA damage was crucial for antitumor immunotherapies to treat GBM.
Project description:Immuno-LC-PRM assay was developed to simultaneously quantify the expression levels of six immune markers (CD8A, CD4, LAG3, PD1, PD-L1 and PD-L2) using as little as 1-2 mg of fresh frozen tissue.