Project description:Mesenchymal stromal cells (MSCs) hold great promise in the field of liver regenerative medicine. However, the mechanisms and reversibility of hepatogenic differentiation in MSCs are poorly understood. Here, we demonstrate that hepatogenic differentiation of MSCs is a reversible process and is modulated by the transforming growth factor beta 1- DNA methyltransferases (TGF-β1-Dnmts) axis. Dnmt1 and Dnmt3a differentially regulate hepatogenic differentiation and de-differentiation in response to the alternation of TGF-β1 concentration. Knockdown of Dnmt1 accelerates the hepatogenic differentiation in MSCs-derived hepatocyte-like cells (dHeps) whereas Knockdown of Dnmt3a represses hepatogenic differentiation. Conclusions: Our finding first demonstrates that epigenetic regulation by Dnmts in response to stimulation from the surrounding microenvironment controls the reversibility of hepatogenic differentiation in MSCs. Manipulation of Dnmts provides a rapid and efficient differentiation protocol to generate functional dHeps from MSCs that may provide clinical potential for regenerative medicine.
Project description:Advancing precision medicine in the field of cancer is still curbed by the fact that a rational basis to predict treatment outcome is missing. To unravel the mechanism behind targeted drugs (trastuzumab, pertuzumab, erlotinib), mathematical modeling employing ordinary differential equations (ODE) was combined with wet-lab experimentation. Experimentation relied on systematic perturbation experiments to monitor the signaling-response towards drugs in the context of EGF signaling in the HER2+ cell lines SKBR3 and HCC1954.
Project description:Our objective was to identify the potential autoantibody markers in meningiomas using high-density human proteome arrays (~17,000 full-length recombinant human proteins). This study revealed the dysregulation of 489 and 104 proteins in grades I and II of meningioma, respectively, along with the enrichment of signalling pathways which play a major role in the manifestation of the disease. This study revealed the dysregulation of 489 and 104 proteins in grades I and II of meningioma, respectively, along with the enrichment of signalling pathways which play a major role in the manifestation of the disease. Autoantibody targets like IGHG4, CRYM, EFCAB2, STAT6, HDAC7A and CCNB1 were dysregulated across both grades.
Project description:Purpose: Mutations in TP53 induce autoantibody immune responses in a subset of cancer patients, which have been proposed as biomarkers for early detection. Here, we investigate the association of p53 specific autoantibodies with multiple tumor subtypes and determine the association with p53 mutation status and epitope specificity. Experimental Design: IgG p53 autoantibodies (p53-AAb), were quantified in 412 serum saples using a programmable ELISA assay from patients with serous ovarian, pancreatic adenocarcinoma, and breast cancer. To determine if patients generated mutation specific autoantibodies we designed a panel of the most relevant 51 p53 point mutant proteins, to be displayed on custom programmable protein microarrays. To determine the epitope specificity we displayed 12 overlapping tiling fragments and 38 N- and C-terminal deletions spanning the length of the wild-type p53 proteins. Results: We detected p53-AAb with sensitivities of 58.8% (ovarian), 22% (pancreatic), 32% (triple negative breast cancer), and 10.2% (HER2+ breast cancer) at 94% specificity. Sera with p53-AAb contained broadly-reactive autoantibodies to 51 displayed p53 mutant proteins, demonstrating a polyclonal response to common epitopes. All p53-AAb displayed broad polyclonal immune response to both continuous and discontinuous epitopes at the N- and C-terminus as well as the DNA binding domain. Conclusion and clinical relevance: In this comprehensive analysis, mutations in tumor p53 induce strong, polyclonal autoantibodies with broadly reactive epitope specificity.
Project description:Purpose: There is evidence that therapeutic cancer vaccines can lengthen survival for some cancer patients, but responses vary widely from one person to another. Methods to predict clinical outcomes will advance the field and provide new insights into critical determinants of in vivo efficacy. This study uses a high-throughput glycan microarray to assess correlations between a subject's overall survival after receiving PROSTVAC-VF and his anti-glycan humoral responses occuring in the first months after treatment with PROSTVAC-VF. Results: Humoral responses to the terminal Forssman disaccharide (Fsdi) were found to have a statistically significant correlation with survival. Long-term survival was approximately doubled in subjects with four-fold or larger anti-Fsdi responses relative to subjects with little or no anti-Fsdi response. This survival correlation was specific to vaccine treatment, as no correlation was observed in control patients immunized with wild-type poxviruses lacking the key tumor antigen, prostate specific antigen (PSA). Moreover, anti-Fsdi humoral responses were not correlated with general measures of disease severity, such as PSA levels, Gleason score, or Halabi predicted survival. Conclusion: In addition to reporting a new biomarker for monitoring benefical responses to PROSTVAC-VF, this study highlights the potential of glycan microarray technology for personalized medicine.
Project description:Purpose: There is evidence that therapeutic cancer vaccines can lengthen survival for some cancer patients, but responses vary widely from one person to another. Methods to predict clinical outcomes will advance the field and provide new insights into critical determinants of in vivo efficacy. This study uses a high-throughput glycan microarray to assess correlations between a subject's overall survival after receiving PROSTVAC-VF and his anti-glycan humoral responses occuring in the first months after treatment with PROSTVAC-VF. Results: Humoral responses to the terminal Forssman disaccharide (Fsdi) were found to have a statistically significant correlation with survival. Long-term survival was approximately doubled in subjects with four-fold or larger anti-Fsdi responses relative to subjects with little or no anti-Fsdi response. This survival correlation was specific to vaccine treatment, as no correlation was observed in control patients immunized with wild-type poxviruses lacking the key tumor antigen, prostate specific antigen (PSA). Moreover, anti-Fsdi humoral responses were not correlated with general measures of disease severity, such as PSA levels, Gleason score, or Halabi predicted survival. Conclusion: In addition to reporting a new biomarker for monitoring benefical responses to PROSTVAC-VF, this study highlights the potential of glycan microarray technology for personalized medicine.
Project description:Purpose: There is evidence that therapeutic cancer vaccines can lengthen survival for some cancer patients, but responses vary widely from one person to another. Methods to predict clinical outcomes will advance the field and provide new insights into critical determinants of in vivo efficacy. This study uses a high-throughput glycan microarray to assess correlations between a subject's overall survival after receiving PROSTVAC-VF and his anti-glycan humoral responses occuring in the first months after treatment with PROSTVAC-VF. Results: Humoral responses to the terminal Forssman disaccharide (Fsdi) were found to have a statistically significant correlation with survival. Long-term survival was approximately doubled in subjects with four-fold or larger anti-Fsdi responses relative to subjects with little or no anti-Fsdi response. This survival correlation was specific to vaccine treatment, as no correlation was observed in control patients immunized with wild-type poxviruses lacking the key tumor antigen, prostate specific antigen (PSA). Moreover, anti-Fsdi humoral responses were not correlated with general measures of disease severity, such as PSA levels, Gleason score, or Halabi predicted survival. Conclusion: In addition to reporting a new biomarker for monitoring benefical responses to PROSTVAC-VF, this study highlights the potential of glycan microarray technology for personalized medicine.
Project description:Therapeutic neo-vasculogenesis in vivo can be achieved by the co-transplantation of human endothelial colony-forming progenitor cells (ECFCs) with mesenchymal stem/progenitor cells (MSPCs).The underlying mechanism is not completely understood thus hampering the development of novel stem cell therapies.We hypothesized that proteomic profiling could be used to retrieve the in vivo signaling signature during the initial phase of human neo-vasculogenesis. ECFCs and MSPCs were therefore either transplanted alone or co-transplanted subcutaneously into immune deficient mice. Early cell signaling, occurring within the first 24 hours in vivo, was analyzed using antibody microarray proteomic profiling.Vessel formation and persistence were verified in parallel transplants for up to 24 weeks. Proteomic analysis revealed significant alteration of regulatory components including caspases, calcium/calmodulin-dependent protein kinase, DNA protein kinase,human ErbB2 receptor-tyrosine kinase as well as mitogen-activated protein kinases.Therapeutic candidate caspase-4 was selected from array results for targeting vascular network formation in vitro as well as modulating therapeutic vasculogenesis in vivo. As a proof-of-principle, caspase-4 and general caspase-blocking led to diminished endothelial network formation in vitro and significantly decreased vasculogenesis in vivo. Proteomic profiling ex vivo thus unraveled a signaling signature which can be targeted to modulate neo-vasculogenesis in vivo.
Project description:Introduction: Autoreactivity to histones is a pervasive feature of several human autoimmune disorders including systemic lupus erythematosus (SLE). Specific post-translational modifications (PTMs) of histones within neutrophil extracellular traps (NETs) may potentially drive the process by which tolerance to these chromatin-associated proteins is broken. We hypothesized that NETs and their unique histone PTMs might be capable of inducing autoantibodies that target histones. Methods: We developed a novel and efficient method for the in vitro production, visualization, and broad profiling of histone-PTMs of human and murine NETs. We also immunized Balb/c mice with murine NETs and profiled their sera on autoantigen and histone peptide microarrays for evidence of autoantibody production to their immunogen. Results: We confirmed specificity toward acetyl-modified histone H2B as well as to other histone PTMs in sera from patients with SLE known to have autoreactivity against histones. We observed enrichment for distinctive histone marks of transcriptionally silent DNA during NETosis triggered by diverse stimuli. However, NETs derived from human and murine sources did not harbor many of the PTMs toward which autoreactivity was observed in patients with SLE or in MRL/lpr mice. Further, while murine NETs were weak autoantigens in vivo, there was only partial overlap in the IgG and IgM autoantibody profiles induced by vaccination of mice with NETs and those seen in patients with SLE. Conclusions: Isolated in vivo exposure to NETs is insufficient to break tolerance and may involve additional factors that have yet to be identified.