Cuproptosis-related genes score and its hub gene GCSH: A novel predictor for cholangiocarcinomas prognosis based on RNA seq and experimental analyses.

Background: Recent researches have demonstrated that cuproptosis, a copper-dependent cell death mechanism, is related to tumorigenesis, progression, clinical prognosis, tumor microenvironment, and drug sensitivity. Nevertheless, the function and impact of cuproptosis in cholangiocarcinoma (CCA), remain elusive. Methods: Utilizing data obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA-CHOL) datasets, we conducted subgroup typing of CCA according to cuproptosis-related genes (CRGs) and explored functional differences and prognostic value between groups. A CRG score was established considering clinical prognosis and gene expression. Furthermore, differences in the immune microenvironment, response to immunotherapy, metabolic patterns, and cancer progression characteristics between high- and low-risk groups were examined on the basis of these scores. In vitro experiments validated the function of the key gene glycine cleavage system protein H (GCSH) in cellular and tissues, respectively. Results: Prognostic models established on the basis of subgroup genetic differences achieved satisfactory results in validation. Metabolic-related gene expression levels and tumor microenvironment distribution were significantly different between the high and low CRG groups. GCSH was revealed as the singular prognostic CRG in CCA (HR =6.04; 95% CI: 1.15-31.80). Moreover, inhibition of the cupcoptosis key gene GCSH attenuated the malignant ability of CCA cell lines in vitro, including cell proliferation, migration and invasion, and this function of GCSH may be achieved via JAK-STAT signaling in CCA. Conclusion: The CRG scoring system accurately predicts prognosis and opens up new possibilities for cuproptosis-related therapy for CCA. The cuproptosis key gene GCSH has been preliminarily confirmed as a reliable therapeutic target or prognostic marker for CCA patients.

Population pharmacokinetics of polymyxin B in patients with liver dysfunction.

AIMS: Polymyxin B (PMB) is widely used to treat infections caused by multidrug-resistant Gram-negative pathogens. Currently, the pharmacokinetic data of PMB in patients with liver dysfunction are limited. This study aimed to develop a population pharmacokinetic (PopPK) model of PMB in patients with liver dysfunction and identify the factors affecting PMB pharmacokinetics. METHODS: We conducted a retrospective pharmacokinetic study involving 136 adults with different levels of liver function. Nonlinear mixed effects modelling was used to develop a PopPK model of PMB. Monte Carlo simulation was used to design PMB dosage schedules across various liver and renal functions. RESULTS: PMB pharmacokinetic analyses included 401 steady-state concentrations in 136 adult patients. A one-compartment pharmacokinetic model with first-order absorption and elimination was used to describe the data. The typical population value of PMB clearance was 2.43 L/h and the volume of distribution was 23.11 L. This study revealed that creatinine clearance (CrCL) and Child-Pugh class were significantly associated with PMB pharmacokinetic parameters; however, clinically relevant variations of dose-normalized drug exposure were not significant. For patients with a minimum inhibitory concentration of ≤0.5 mg/L, the appropriate dose was 40-75 mg/12-h. When the dose exceeded 100 mg/12-h, the risk of nephrotoxicity increased significantly. CONCLUSIONS: This study provided PMB pharmacokinetic information for patients with liver dysfunction. Patients with renal and liver dysfunctions may not require an initial dose adjustment. Rather than PopPK-guided dose adjustment, therapeutic drug monitoring of PMB plays a more direct role in optimizing dosing regimens based on its therapeutic window.

A self-assembling CXCR4-targeted pyroptosis nanotoxin for melanoma therapy.

While immunotherapy has emerged as a promising strategy to treat melanoma, the limited availability of immunotherapeutic agents in tumors due to the immunosuppressive tumor microenvironment dampens its efficacy. Pyroptosis is a gasdermin-mediated programmed necrosis that triggers the inflammatory tumor microenvironment and enhances the efficacy of tumor immunotherapy. Here, we prove that the CXCR4 antagonist T22 peptide specially targeted and became internalized into CXCR4+ melanoma cells. Then we report a self-assembling nanotoxin that can be used to spatiotemporally target CXCR4-expression melanoma cells and enable tunable cellular pyroptosis. Specific activation of caspase 3 signal transduction triggers gasdermin-E-mediated pyroptosis. This nanotoxin induces pyroptotic cell death resulting in enhanced antitumor efficacy and minimized systemic side effects toward melanoma in vivo. This study offers new insights into how to engineer nanotoxins with tunable pyroptosis activity through specifically targeting CXCR4 for biomedical applications.

MicroRNA-26a targets the mdm2/p53 loop directly in response to liver regeneration.

Liver regeneration (LR) is the result of a dynamic balance between the increased proliferation and decreased apoptosis of hepatocytes. However, the role of microRNA (miR)­26a in regulating complex signalling networks involving E3 ubiquitin­protein ligase Mdm2 (mdm2), p53, p21 and p27 in the process of LR is currently unclear. In the present study, it was hypothesized that miR­26a may negatively regulate the mdm2/p53 signalling loop in response to LR. In vitro experiments were performed, whereby mouse liver cells were transfected with an miR­26a vector or an anti/miR­26a vector. Cell proliferation was analysed using an MTS assay and cell apoptosis, and cell cycle progression were analysed by flow cytometry. In addition, the expression of mdm2, p53, p21 and p27 were assessed using western blotting and reverse transcription­quantitative polymerase chain reaction analyses. Dual­luciferase reporter assays were also used to examine the association between mdm2 and miR­26a. A 70% partial hepatectomy in C57BL/6J mice was then performed, which was followed by injection with an mdm2­cDNA vector or an mdm2­small interfering RNA vector. The liver­to­body weight ratio and liver function of mice were measured at 72 h following vector administration. The results demonstrated an increase in hepatocyte proliferation accompanied by decreased hepatocyte apoptosis levels. In addition, inhibition of miR­26a expression was associated with a marked increase in mdm2 expression, while the expression of p53, p21 and p27 was decreased when compared with negative controls. The opposite effects were observed when miR­26a was overexpressed. Notably, miR­26a was demonstrated to target the 3'­untranslated region of mdm2 directly. The results of the present study are the first to demonstrate as far as the authors are aware that the mdm2/p53 negative feedback loop may be targeted by miR­26a directly in response to LR, and that mdm2 negatively regulates p53, p21 and p27 but not miR­26a. miR­26a may therefore function as an important factor that regulates the interaction between mdm2 and p53.

Inhibition of microRNA-16 facilitates the paclitaxel resistance by targeting IKBKB via NF-κB signaling pathway in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common malignant tumor usually resistant to chemotherapy. MicroRNAs play important roles in modulation of carcinogenesis and chemoresistance, which miR-16 has been reported to mediate chemoresistance in many types of cancers. However, the role of miR-16 in HCC remains unknown. The aim of this study was to investigate whether miR-16 is participated in chemoresistance in HCC and shed light on the underlying molecular mechanisms. The findings of the current study discover that miR-16 is down-regulated in HCC tissue and cell lines. The results demonstrate that the inhibition of miR-16 renders resistance to paclitaxel in vitro and in vivo by targeting IKBKB via NF-κB signaling pathway, suggesting that miR-16 may be a meaningful therapeutic potential to overcome drug resistance in HCC.