Deciphering the prognostic features of bladder cancer through gemcitabine resistance and immune-related gene analysis and identifying potential small molecular drug PIK-75.

BACKGROUND: Bladder cancer (BCa) stands out as a prevalent and highly lethal malignancy worldwide. Chemoresistance significantly contributes to cancer recurrence and progression. Traditional Tumor Node Metastasis (TNM) stage and molecular subtypes often fail to promptly identify treatment preferences based on sensitivity. METHODS: In this study, we developed a prognostic signature for BCa with uni-Cox + LASSO + multi-Cox survival analysis in multiple independent cohorts. Six machine learning algorithms were adopted to screen out the hub gene, RAC3. IHC staining was used to validate the expression of RAC3 in BCa tumor tissue. RT-qPCR and Western blot were performed to detect and quantify the mRNA and protein levels of RAC3. CCK8, colony formation, wound healing, and flow cytometry analysis of apoptosis were employed to determine cell proliferation, migration, and apoptosis. Molecular docking was used to find small target drugs, PIK-75. 3D cell viability assay was applied to evaluate the ATP viability of bladder cancer organoids before and after PIK-75 treated. RESULTS: The established clinical prognostic model, GIRS, comprises 13 genes associated with gemcitabine resistance and immunology. This model has demonstrated robust predictive capabilities for survival outcomes across various independent public cohorts. Additionally, the GIRS signature shows significant correlations with responses to both immunotherapy and chemotherapy. Leveraging machine learning algorithms, the hub gene, RAC3, was identified, and potential upstream transcription factors were screened through database analysis. IHC results showed that RAC3 was higher expressed in GEM-resistant BCa patients. Employing molecular docking, the small molecule drug PIK-75, as binding to RAC3, was identified. Experiments on cell lines, organoids and animals validated the biological effects of PIK-75 in bladder cancer. CONCLUSIONS: The GIRS signature offers a valuable complement to the conventional anatomic TNM staging system and molecular subtype stratification in bladder cancer. The hub gene, RAC3, plays a crucial role in BCa and is significantly associated with resistance to gemcitabine. The small molecular drug, PIK-75 having the potential as a therapeutic agent in the context of gemcitabine-resistant and immune-related pathways.

An unprecedented endocrine target for ovarian cancer: inhibiting 17ß-HSD7 supresses cancer cell proliferation and arrests G2/M cycle.

Epithelial ovarian cancer, widely suggested as endocrine-related cancer, yields a low survival rate among patients. Despite intensive research for nearly a century, there have been no fundamental advances in treatment. The reductive 17ß-HSD7 is a special enzyme possessing a remarkable dual activity in both the biosynthesis of the most potent estrogen estradiol and the inactivation of the most active androgen dihydrotestosterone. In the present study, we observed over-expression of 17ß-HSD7 in EOC cells such as OVCAR-3 and SKOV-3, in agreement with integrative data analysis demonstrating overexpression of 17ß-HSD7 in EOC tissues. After knocking down 17ß-HSD7, SKOV-3 cell proliferation decreased by 29%, cell arrest in the G2/M phase increased by 25% with cyclin B1/Cdk1 inhibition. Inhibition of 17ß-HSD7 in EOC cells triggered negative feedback of its expression, which further decreased the estradiol level to more than 60% under the experimental condition. Such inhibition increased the dihydrotestosterone level to many times higher and suppressed cell proliferation. Thus, 17ß-HSD7 is demonstrated to be a promising target for the endeavor against the malignant ovarian cancer, a menace in human life. The targeting of such an enzyme thus provides exceptional scientific importance.

Damage to dopaminergic neurons by oxidative stress in Parkinson's disease (Review).

Oxidative stress is increasingly recognized as a central event contributing to the degeneration of dopaminergic neurons in the pathogenesis of Parkinson's disease (PD). Although reactive oxygen species (ROS) production is implicated as a causative factor in PD, the cellular and molecular mechanisms linking oxidative stress with dopaminergic neuron death are complex and not well characterized. The primary insults cause the greatest production of ROS, which contributes to oxidative damage by attacking all macromolecules, including lipids, proteins and nucleic acids, leading to defects in their physiological function. Consequently, the defects in these macromolecules result in mitochondrial dysfunction and neuroinflammation, which subsequently enhance the production of ROS and ultimately neuronal damage. The interaction between these various mechanisms forms a positive feedback loop that drives the progressive loss of dopaminergic neurons in PD, and oxidative stress­mediated neuron damage appears to serve a central role in the neurodegenerative process. Thus, understanding the cellular and molecular mechanisms by which oxidative stress contributes to the loss of dopaminergic neurons may provide a promising therapeutic approach in PD treatment.

Mitochondria-mediated damage to dopaminergic neurons in Parkinson's disease (Review).

Mitochondria are important organelles in virtually all eukaryotic cells, and are involved in a wide range of physiological and pathophysiological processes. Besides the generation of cellular energy in the form of adenosine triphosphate, mitochondria are also involved in calcium homeostasis, reactive oxygen species production and the activation of the intrinsic cell death pathway, thus determining cell survival and death. Mitochondrial abnormalities have been implicated in a wide range of disorders, including neurodegenerative disease such as Parkinson's disease (PD), and considered as a primary cause and central event responsible for the progressive loss of dopaminergic neurons in PD. Thus, reversion or attenuation of mitochondrial dysfunction should alleviate the severity or progression of the disease. The present review systematically summarizes the possible mechanisms associated with mitochondria­mediated dopaminergic neuron damage in PD, in an attempt to elucidate the requirement for further studies for the development of effective PD treatments.

Damage to dopaminergic neurons is mediated by proliferating cell nuclear antigen through the p53 pathway under conditions of oxidative stress in a cell model of Parkinson's disease.

Oxidative stress is widely considered as a central event in the pathogenesis of Parkinson's disease (PD). The mechanisms underlying the oxidative damage-mediated loss of dopaminergic neurons in PD are not yet fully understood. Accumulating evidence has indicated that oxidative DNA damage plays a crucial role in programmed neuronal cell death, and is considered to be at least partly responsible for the degeneration of dopaminergic neurons in PD. This process involves a number of signaling cascades and molecular proteins. Proliferating cell nuclear antigen (PCNA) is a pleiotropic protein affecting a wide range of vital cellular processes, including chromatin remodelling, DNA repair and cell cycle control, by interacting with a number of enzymes and regulatory proteins. In the present study, the exposure of PC12 cells to 1-methyl-4-phenylpyridinium (MPP+) led to the loss of cell viability and decreased the expression levels of PCNA in a dose- and time-dependent manner, indicating that this protein may be involved in the neurotoxic actions of MPP+ in dopaminergic neuronal cells. In addition, a significant upregulation in p53 expression was also observed in this cellular model of PD. p53 is an upstream inducer of PCNA and it has been recognized as a key contributor responsible for dopaminergic neuronal cell death in mouse models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD. This indicates that MPP+-induced oxidative damage is mediated by the downregulation of PCNA through the p53 pathway in a cellular model of PD. Thus, our results may provide some novel insight into the molecular mechanisms responsible for the development of PD and provide new possible therapeutic targets for the treatment of PD.

Atorvastatin protects endothelial colony­forming cells against H2O2­induced oxidative damage by regulating the expression of annexin A2.

Endothelial dysfunction and injury are central events in the pathogenesis of ischemic vascular disorders. Endothelial progenitor cells (EPCs) are mobilized from the bone marrow into the peripheral circulation, where they locate to sites of injured endothelium and are involved in endothelial repair and vascular regeneration. During these processes, EPCs are exposed to oxidative stress, a crucial pathological condition, which occurs during vascular injury and limits the efficacy of EPCs in the repair of injured endothelium. Statins are effective inhibitors of 3­hydroxy­3­methylglutaryl coenzyme A reductase, and are commonly used to manage and prevent ischemic vascular disease by reducing plasma cholesterol levels. In addition to lowering cholesterol, statins have also been reported to exert pleiotropic actions, including anti­inflammatory and anti­oxidative activities. The present study aimed to investigate the ability of atorvastatin to protect endothelial colony­forming cells (ECFCs), a homogeneous subtype of EPCs, from hydrogen peroxide (H2O2)­induced oxidative damage, and to determine the mechanism underlying this protective action. MTT assay, acridine orange/ethidium bromide staining, reactive oxygen species assay, western blot analysis and tube formation assay were employed. The results demonstrated that H2O2 induced cell death and decreased the tube­forming ability of the ECFCs, in a concentration­dependent manner; however, these effects were partially attenuated following administration of atorvastatin. The reversion of the quantitative and qualitative impairment of the H2O2­treated ECFCs appeared to be mediated by the regulation of annexin A2, as the expression levels of annexin A2 were decreased following treatment with H2O2 and increased following treatment with atorvastatin. These results indicated that annexin A2 may be involved in the H2O2­induced damage of ECFCs, and in the protective activities of atorvastatin in response to oxidative stress.

Association of glycogen synthase kinase-3ß with Parkinson's disease (review).

Glycogen synthase kinase-3 (GSK-3) is a pleiotropic serine/threonine protein kinase found in almost all eukaryotes. It is structurally highly conserved and has been identified as a multifaceted enzyme affecting a wide range of biological functions, including gene expression and cellular processes. There are two closely related isoforms of GSK-3; GSK-3α and GSK-3ß. The latter appears to play crucial roles in regulating the pathogenesis of diverse diseases, including neurodegenerative disease. The present review focuses on the involvement of this protein in Parkinson's disease (PD), a common neurodegenerative disorder characterized by the gradually progressive and selective loss of dopaminergic neurons, and by intracellular inclusions known as Lewy bodies (LBs) expressed in surviving neurons of the substantia nigra (SN). GSK-3ß is involved in multiple signaling pathways and has several phosphorylation targets. Numerous apoptotic conditions can be facilitated by the GSK-3ß signaling pathways. Studies have shown that GSK-3ß inhibition protects the dopaminergic neurons from various stress-induced injuries, indicating the involvement of GSK-3ß in PD pathogenesis. However, the underlying mechanisms of the protective effect of GSK-3ß inhibition on dopaminergic neurons in PD is not completely understood. Multiple pathological events have been recognized to be responsible for the loss of dopaminergic neurons in PD, including mitochondrial dysfunction, oxidative stress, protein aggregation and neuroinflammation. The present review stresses the regulatory roles of GSK-3ß in these events and in dopaminergic neuron degeneration, in an attempt to gain an improved understanding of the underlying mechanisms and to provide a potential effective therapeutic target for PD.

A clinical and neuropathological study of Chinese patients with diabetic peripheral neuropathy.

OBJECTIVE: To examine whether the neuropathological and metabolic changes of peripheral nerves are correlated to clinical features in diabetes mellitus type 2 patients with peripheral neuropathy. METHODS: 147 type 2 diabetic patients with signs/symptoms of diabetic peripheralneuropathy (DPN) aged 53.4 ± 12.3 years and 134 healthy volunteers aged 55.5 ± 11.7 years were investigated for fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), and red blood cell sorbitol (RBC sorbitol) in addition to nerve conduction velocity (NCV). Among the 147 diabetic patients, 10 patients underwent superficial peroneal nerve biopsy for light and electron microscopy. RESULTS: In the experimental group, the levels of HbA1c and RBC sorbitol showed significant increase compared with the controlled group, whereas motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) both showed decline and SNCV decreased at a greater extent. Morphologically, there were various degrees of nerve fiber loss, associated with axon degeneration and capillary luminal narrowing in 10 patients undergone nerve biopsy. CONCLUSION: The metabolic change of sorbitol, the consequently observed changes in NCV and histopathology of peripheral nerves are positively correlated with the duration of diabetes and overall level of blood glucose.

Guanosine exerts neuroprotective effects by reversing mitochondrial dysfunction in a cellular model of Parkinson's disease.

The mitochondria are the most important cytoplasmic organelles in determining cell survival and death. Mitochondrial dysfunction leads to a wide range of disorders, including neurodegenerative diseases. The central events in the mitochondrial­dependent cell death pathway are the activation of the mitochodrial permeability transition pore (mPTP) and the disruption of mitochondrial membrane potential, which cause the release of apoptogenic molecules and finally lead to cell death. This is thought to be at least partly responsible for the loss of dopaminergic neurons in Parkinson's disease (PD); thus, the attenuation of mitochondrial dysfunction may contribute to alleviating the severity and progression of this disease. Guanosine is a pleiotropic molecule affecting multiple cellular processes, including cellular growth, differentiation and survival. Its protective effects on the central nervous system and and on several cell types by inhibiting apoptosis have been shown in a number of pathological conditions. This study aimed to analyze the ability of guanosine to protect neuronal PC12 cells from the toxicity induced by 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which mediates selective damage to dopaminergic neurons and causes irreversible Parkinson-like symptoms in humans and primates. Our results demonstrated that the apoptosis of PC12 cells induced by MPP+ was significantly prevented by pre-treatment for 3 h with guanosine. In addition, guanosine attenuated the MPP+-induced collapse of mitochondrial transmembrane potential and prevented the sebsequent activation of caspase-3, thereby protecting dopaminergic neurons against mitochondrial stress-induced damage.

α-lipoic acid protects dopaminergic neurons against MPP+-induced apoptosis by attenuating reactive oxygen species formation.

Reactive oxygen species (ROS) elicited by oxidative stress are widely recognized as a major initiator in the dege-neration of dopaminergic neurons distinctive of Parkinson's disease (PD). The interaction of ROS with mitochondria triggers sequential events in the mitochondrial cell death pathway, which is thought to be responsible for ROS-mediated neurodegeneration in PD. α-lipoic acid (LA) is a pleiotropic compound with potential pharmacotherapeutic value against a range of pathophysiological insults. Its protective actions against oxidative damage by scavenging ROS and reducing production of free radicals have been reported in various in vitro and in vivo systems. This study analyzed the ability of LA to protect PC12 neuronal cells from toxicity of 1-methyl-4-phenylpyridinium (MPP+), the neurotoxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) which is known to kill dopaminergic neurons selectively and to cause severe parkinsonism-like symptoms in humans and primate animals. Our results demonstrate that the apoptosis of PC12 cells elicited by MPP+ could be significantly prevented by pretreatment with LA for 1 h. In addition, LA inhibits intercellular ROS levels and the mitochondrial transmembrane permeability, the key players in the pathogenesis of PD, thereby protecting dopaminergic neuronal cells against oxidative damage.