Objective Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all... Show moreObjective Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all forms of chemotherapy and immunotherapy, leading to a 5-year survival rate of 9%. Our study aims to add novel small molecule therapeutics for the treatment of PDAC. Design We have studied whether TAK-981, a novel highly selective and potent small molecule inhibitor of the small ubiquitin like modifier (SUMO) activating enzyme E1 could be used to treat a preclinical syngeneic PDAC mouse model and we have studied the mode of action of TAK-981. Results We found that SUMOylation, a reversible post-translational modification required for cell cycle progression, is increased in PDAC patient samples compared with normal pancreatic tissue. TAK-981 decreased SUMOylation in PDAC cells at the nanomolar range, thereby causing a G2/M cell cycle arrest, mitotic failure and chromosomal segregation defects. TAK-981 efficiently limited tumour burden in the KPC3 syngeneic mouse model without evidence of systemic toxicity. In vivo treatment with TAK-981 enhanced the proportions of activated CD8 T cells and natural killer (NK) cells but transiently decreased B cell numbers in tumour, peripheral blood, spleen and lymph nodes. Single cell RNA sequencing revealed activation of the interferon response on TAK-981 treatment in lymphocytes including T, B and NK cells. TAK-981 treatment of CD8 T cells ex vivo induced activation of STAT1 and interferon target genes. Conclusion Our findings indicate that pharmacological inhibition of the SUMO pathway represents a potential strategy to target PDAC via a dual mechanism: inhibiting cancer cell cycle progression and activating anti-tumour immunity by inducing interferon signalling. Show less
Objective Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all... Show moreObjective Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all forms of chemotherapy and immunotherapy, leading to a 5-year survival rate of 9%. Our study aims to add novel small molecule therapeutics for the treatment of PDAC.Design We have studied whether TAK-981, a novel highly selective and potent small molecule inhibitor of the small ubiquitin like modifier (SUMO) activating enzyme E1 could be used to treat a preclinical syngeneic PDAC mouse model and we have studied the mode of action of TAK-981.Results We found that SUMOylation, a reversible post-translational modification required for cell cycle progression, is increased in PDAC patient samples compared with normal pancreatic tissue. TAK-981 decreased SUMOylation in PDAC cells at the nanomolar range, thereby causing a G2/M cell cycle arrest, mitotic failure and chromosomal segregation defects. TAK-981 efficiently limited tumour burden in the KPC3 syngeneic mouse model without evidence of systemic toxicity. In vivo treatment with TAK-981 enhanced the proportions of activated CD8 T cells and natural killer (NK) cells but transiently decreased B cell numbers in tumour, peripheral blood, spleen and lymph nodes. Single cell RNA sequencing revealed activation of the interferon response on TAK-981 treatment in lymphocytes including T, B and NK cells. TAK-981 treatment of CD8 T cells ex vivo induced activation of STAT1 and interferon target genes.Conclusion Our findings indicate that pharmacological inhibition of the SUMO pathway represents a potential strategy to target PDAC via a dual mechanism: inhibiting cancer cell cycle progression and activating anti-tumour immunity by inducing interferon signalling. Show less
Burg, M. van der; Mahlaoui, N.; Gaspar, H.B.; Pai, S.Y.; IEWP-EBMT 2019
Identification of the cellular mechanisms involved in the occurrence and persistence of autoreactive lymphocytes is key for understanding T1D etiology. Comparing autoreactive T lymphocytes from... Show moreIdentification of the cellular mechanisms involved in the occurrence and persistence of autoreactive lymphocytes is key for understanding T1D etiology. Comparing autoreactive T lymphocytes from healthy individuals and T1D patients can provide clues as to what the driving force is for the destruction of β-cells and might designate potential targets for (immune) intervention. Elucidating in what way T1D associated gene variants actually contribute to disease development, i.e. understanding the functional aspects of genetic risk, and how genetic control of autoantigens influences autoimmunity may provide crucial clues to the clarification of the enigma of T1D. This thesis aims to answer several of these issues by investigating the role of transcriptional and post-transcriptional gene control in T1D. Show less
Looman, K.I.M.; Jansen, M.A.E.; Voortman, T.; Heuvel, D. van den; Jaddoe, V.W.V.; Franco, O.H.; ... ; Moll, H.A. 2017
In peripheral arterial occlusive disease (PAOD), the formation of an atherosclerotic lesion eventually results in a significant stenosis of a major artery thereby disrupting blood flow in... Show moreIn peripheral arterial occlusive disease (PAOD), the formation of an atherosclerotic lesion eventually results in a significant stenosis of a major artery thereby disrupting blood flow in peripheral arteries towards lower limb tissue. Unfortunately, there is a substantial number of patients that suffer from severe critical limb ischemia, which is associated with a poor prognosis and high rates of amputation and mortality. Despite state-of-the-art revascularization treatment options and optimal control of co-morbidities these 'no option' patients remain at high risk for limb amputation. It is these patients that require new therapeutic applications to augment neovascularization and prevent them from limb amputation. Expansion of our current knowledge is required to gain insight in cellular and molecular mechanisms that are involved in neovascularization, to optimize revascularization therapies for patients with critical limb ischemia. This thesis provides a role for multiple leukocytes in blood flow recovery, in particular Natural Killer cells and CD4+ T lymphocytes, and shows that genetic differences in the Natural Killer gene complex induce differences in vascular remodeling. It was also shown how growth factor expression, signaling and regulation of gene expression modulate revascularization. Show less
In rheumatoid arthritis, an inflammatory infiltrate accumulates and persists in the synovial membrane. Synovial T cells display a number of particular characteristics. While displaying markers of... Show moreIn rheumatoid arthritis, an inflammatory infiltrate accumulates and persists in the synovial membrane. Synovial T cells display a number of particular characteristics. While displaying markers of recent activation, synovial T lymphocytes respond poorly to mitogenic stimuli and their cytokine production appears to be suppressed both in situ and in vitro. One of the critical hallmarks from synovial T cells is that they suffer from oxidative stress. Oxidative stress in synovial fluid T lymphocytes inhibits T cell receptor (TCR)-dependent phosphorylation of pivotal signaling molecules, required for efficient T cell proliferation, and contributes to severe hyporesponsiveness of these cells. Chronic exposure of T lymphocytes to free radicals produced by activated phagocytic cells at the site of inflammation has been proposed to be the major cause of deregulated redox homeostasis in RA. In this thesis we further investigate the source of free radicals. We demonstrate that the oxidative stress found in synovial T cells is not the result from exogenous sources but originates from (an) intracellular activated oxidase(s). We demonstrate that the oxidase generating ROS in SF T cells is controlled by the small GTPases Ras and Rap1. We show that in synovial T cells Ras can be activated by a variety of cytokines. Rap1 inhibition is induced by direct cell-cell contact of T lymphocytes with antigen presenting cells (APC), and can be prevented by blocking the co-stimulatory T cell receptor CD28 with CTLA-4. Howevever, we did therapy with a nutrient supplement containing high dose anti-oxidants and poly-unsaturated fatty acids did not lead to clinical improvement of RA disease activity, nor therapy with high dose intravenously administered N-acetyl cysteine. Show less
