ABSTRACT
Disorders of polyamine metabolism may contribute to the development of hepatocellular carcinoma (HCC), but the precise mechanism remains unknown. This study reports that spermine synthase (SMS), an enzyme involved in polyamine biosynthesis, is overexpressed in HCC and not associated with hepatitis virus infection in HCC patients. The results of analyzing the clinical data of HCC patients showed that SMS level as a categorical dependent variable was related to clinicopathological features of poor prognosis. Furthermore, the Kaplan-Meier survival analysis and ROC curve indicated that increased SMS level is associated with poor survival rate in HCC and may be a potential biomarker to discriminate HCC tissues. However, SMS overexpression limited the therapeutic effect of immune checkpoint blockade (ICB), which seemed to be related to the immunosuppressive effect of the HCC immune microenvironment formed by higher mRNA transcript levels of immune checkpoints and higher infiltration levels of immunosuppressive cells. In samples with high and low SMS expression, functional enrichment analysis of the differentially expressed genes (DEGs) showed that SMS may be linked to the occurrence and development of HCC by affecting a variety of immune-related pathways, such as Intestinal immune network for IgA production, Fc gamma R-mediated phagocytosis, Antigen processing and presentation, Th1 and Th2 cell differentiation. Subsequently, analysis of the co-expression network of SMS in the liver hepatocellular carcinoma (LIHC) cohort revealed that SMS has a broad impact on multiple important immune- and metabolic-related processes in HCC. In summary, SMS is a promising biomarker to differentiate the prognosis, immune characteristics, and holds promise as a potential target for ICB therapy to improve HCC.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/genetics , Spermine Synthase , Tumor Microenvironment , Liver Neoplasms/genetics , Immunosuppression Therapy , PolyaminesABSTRACT
Prostate cancer continuously progresses following deprivation of circulating androgens originating from the testis and adrenal glands, indicating the existence of oncometabolites beyond androgens. In this study, mass-spectrometry-based screening of clinical specimens and a retrospective analysis on the clinical data of prostate cancer patients indicate the potential oncogenic effects of progesterone in patients. High doses of progesterone activate canonical and non-canonical androgen receptor (AR) target genes. Physiological levels of progesterone facilitate cell proliferation via GATA2. Inhibitors of 3ß-hydroxysteroid dehydrogenase 1 (3ßHSD1) has been discovered and shown to suppress the generation of progesterone, eliminating its transient and accumulating oncogenic effects. An increase in progesterone is associated with poor clinical outcomes in patients and may be used as a predictive biomarker. Overall, we demonstrate that progesterone acts as an oncogenic hormone in prostate cancer, and strategies to eliminate its oncogenic effects may benefit prostate cancer patients.
Subject(s)
Androgens , Prostatic Neoplasms , Carcinogenesis , Humans , Male , Progesterone/pharmacology , Prostatic Neoplasms/drug therapy , Receptors, Androgen/genetics , Retrospective StudiesABSTRACT
Alzheimer's disease (AD) is thought to be caused by amyloid-ß (Aß) accumulation in the central nervous system due to deficient clearance. The aim of the present study was to investigate the effect of ganoderic acid A (GAA) on Aß clearance in microglia and its anti-AD activity. Aß degradation in BV2 microglial cells was determined using an intracellular Aß clearance assay. GAA stimulated autophagosome formation via the Axl receptor tyrosine kinase (Axl)/RAC/CDC42-activated kinase 1 (Pak1) pathway was determined by Western blot analyses, and fluorescence-labeled Aß42 was localized in lysosomes in confocal laser microscopy images. The in vivo anti-AD activity of GAA was evaluated by object recognition and Morris water maze (MWM) tests in an AD mouse model following intracerebroventricular injection of aggregated Aß42. The autophagy level in the hippocampus was assayed by immunohistochemical assessment against microtubule-associated proteins 1A/1B light-chain 3B (LC3B). Intracellular Aß42 levels were significantly reduced by GAA treatment in microglial cells. Additionally, GAA activated autophagy according to increased LC3B-II levels, with this increased autophagy stimulated by upregulating Axl and Pak1 phosphorylation. The effect of eliminating Aß by GAA through autophagy was reversed by R428, an Axl inhibitor, or IPA-3, a Pak1 inhibitor. Consistent with the cell-based assay, GAA ameliorated cognitive deficiency and reduced Aß42 levels in an AD mouse model. Furthermore, LC3B expression in the hippocampus was up-regulated by GAA treatment, with these GAA-specific effects abolished by R428. GAA promoted Aß clearance by enhancing autophagy via the Axl/Pak1 signaling pathway in microglial cells and ameliorated cognitive deficiency in an AD mouse model.
Subject(s)
Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Autophagy/drug effects , Heptanoic Acids/pharmacology , Lanosterol/analogs & derivatives , Microglia/drug effects , Proto-Oncogene Proteins/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Animals , Autophagosomes/drug effects , Autophagosomes/metabolism , Autophagy/genetics , Cell Line , Disease Models, Animal , Hippocampus/drug effects , Hippocampus/metabolism , Hippocampus/pathology , Immunohistochemistry , Lanosterol/pharmacology , Lysosomes/metabolism , Male , Mice , Mice, Inbred C57BL , Microglia/metabolism , Microglia/pathology , Morris Water Maze Test/drug effects , Phosphorylation , Proto-Oncogene Proteins/antagonists & inhibitors , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Signal Transduction/drug effects , Signal Transduction/genetics , p21-Activated Kinases/antagonists & inhibitors , p21-Activated Kinases/metabolism , Axl Receptor Tyrosine KinaseABSTRACT
Aims: The management of myocardial ischemia has been challenged by reperfusion injury. Reactive oxygen species (ROS) production is the critical cause of reperfusion injury, but antioxidant treatment failed to gain satisfactory effects. We hypothesized that improvement of redox homeostasis by preconditioning regulation should potentiate the ability of antioxidants to protect the heart from reperfusion injury. Results: By phenotype-based screening, we identified that dihydrotanshinone I (DT) and protocatechuic aldehyde (PCA) potently protected cardiomyocytes through preconditioning regulation and antioxidant activity, respectively. DT induced transient ROS generation via reversible inhibition of mitochondrial respiratory complex I and thereby stabilizing HIF-1α, while PCA elevated the levels of reduced glutathione (GSH) by providing reducing equivalents to scavenge ROS. HIF-1α, stabilized by DT, transcriptionally upregulated Nrf2 and thereby activated antioxidant enzymes, potentiating PCA to protect cardiomyocytes from reperfusion injury by strengthening intrinsic ROS scavenging capacity. In rat ischemia/reperfusion (I/R) model, sequential administration of DT and PCA, but not in reverse, additively protected the heart from I/R injury, manifested by reduced infarct size and improved cardiac function. These results were further supported by sequential administration of metformin and vitamin E in the rat and porcine I/R models. Innovation and Conclusion: Our work demonstrates that preconditioning regulation of redox state is essential for antioxidants to protect the heart from I/R injury, providing a new direction for the treatment of myocardial injury.
