ABSTRACT
Interstitial lung diseases such as idiopathic pulmonary fibrosis (IPF) are caused by persistent micro-injuries to alveolar epithelial tissues accompanied by aberrant repair processes. IPF is currently treated with pirfenidone and nintedanib, compounds which slow the rate of disease progression but fail to target underlying pathophysiological mechanisms. The DNA repair protein 8-oxoguanine DNA glycosylase-1 (OGG1) has significant roles in the modulation of inflammation and metabolic syndromes. Currently, no pharmaceutical solutions targeting OGG1 have been utilized in the treatment of IPF. In this study we show Ogg1-targeting siRNA mitigates bleomycin-induced pulmonary fibrosis in male mice, highlighting OGG1 as a tractable target in lung fibrosis. The small molecule OGG1 inhibitor, TH5487, decreases myofibroblast transition and associated pro-fibrotic gene expressions in fibroblast cells. In addition, TH5487 decreases levels of pro-inflammatory mediators, inflammatory cell infiltration, and lung remodeling in a murine model of bleomycin-induced pulmonary fibrosis conducted in male C57BL6/J mice. OGG1 and SMAD7 interact to induce fibroblast proliferation and differentiation and display roles in fibrotic murine and IPF patient lung tissue. Taken together, these data suggest that TH5487 is a potentially clinically relevant treatment for IPF but further study in human trials is required.
Subject(s)
DNA Glycosylases , Idiopathic Pulmonary Fibrosis , Pneumonia , Male , Mice , Humans , Animals , Lung/pathology , Idiopathic Pulmonary Fibrosis/chemically induced , Idiopathic Pulmonary Fibrosis/drug therapy , Idiopathic Pulmonary Fibrosis/metabolism , Fibrosis , Pneumonia/metabolism , Bleomycin/toxicity , DNA Glycosylases/genetics , DNA Glycosylases/metabolismABSTRACT
BACKGROUND: Previously, we showed cancer cells rely on the MTH1 protein to prevent incorporation of otherwise deadly oxidised nucleotides into DNA and we developed MTH1 inhibitors which selectively kill cancer cells. Recently, several new and potent inhibitors of MTH1 were demonstrated to be non-toxic to cancer cells, challenging the utility of MTH1 inhibition as a target for cancer treatment. MATERIAL AND METHODS: Human cancer cell lines were exposed in vitro to MTH1 inhibitors or depleted of MTH1 by siRNA or shRNA. 8-oxodG was measured by immunostaining and modified comet assay. Thermal Proteome profiling, proteomics, cellular thermal shift assays, kinase and CEREP panel were used for target engagement, mode of action and selectivity investigations of MTH1 inhibitors. Effect of MTH1 inhibition on tumour growth was explored in BRAF V600E-mutated malignant melanoma patient derived xenograft and human colon cancer SW480 and HCT116 xenograft models. RESULTS: Here, we demonstrate that recently described MTH1 inhibitors, which fail to kill cancer cells, also fail to introduce the toxic oxidized nucleotides into DNA. We also describe a new MTH1 inhibitor TH1579, (Karonudib), an analogue of TH588, which is a potent, selective MTH1 inhibitor with good oral availability and demonstrates excellent pharmacokinetic and anti-cancer properties in vivo. CONCLUSION: We demonstrate that in order to kill cancer cells MTH1 inhibitors must also introduce oxidized nucleotides into DNA. Furthermore, we describe TH1579 as a best-in-class MTH1 inhibitor, which we expect to be useful in order to further validate the MTH1 inhibitor concept.
Subject(s)
DNA Repair Enzymes/antagonists & inhibitors , Enzyme Inhibitors/therapeutic use , Neoplasms/drug therapy , Phosphoric Monoester Hydrolases/antagonists & inhibitors , Pyrimidines/administration & dosage , 8-Hydroxy-2'-Deoxyguanosine , Animals , Cell Line, Tumor , DNA/genetics , DNA/metabolism , DNA Repair Enzymes/genetics , DNA Repair Enzymes/metabolism , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/isolation & purification , Deoxyguanosine/metabolism , Humans , Mice , Neoplasms/genetics , Neoplasms/pathology , Nucleotides/metabolism , Oxidation-Reduction , Phosphoric Monoester Hydrolases/genetics , Phosphoric Monoester Hydrolases/metabolism , Proto-Oncogene Proteins B-raf/genetics , RNA, Small Interfering/genetics , Xenograft Model Antitumor AssaysABSTRACT
Although balloon dilatation is the primary treatment for benign dysphagia, information about the optimal inflation time is lacking. The aim of the current pilot study was to compare 10 seconds inflation time with 2 minutes inflation time, regarding the efficacy. Twenty patients with symptomatic strictures were prospectively studied in a randomized fashion. The 10-second group required an average of 1.4 dilations per patient; the 2-minute group required an average of 1.5 dilations per patient. This pilot study indicates that 10 seconds inflation time is as effective as 2 minutes. Because the treatment is both painful and unpleasant, this is an important finding.
Subject(s)
Deglutition Disorders/surgery , Dilatation/methods , Esophageal Stenosis/surgery , Gastroscopy/methods , Deglutition Disorders/etiology , Esophageal Stenosis/complications , Female , Humans , Male , Middle Aged , Pilot Projects , Treatment OutcomeABSTRACT
Localization of the acid-stable proteinase inhibitor of human cervical mucus within the epithelium of the upper cervix was possible by indirect immunofluorescence.
