RESUMEN
Introduction: Drugs that target reactive oxygen species (ROS) metabolism have progressed the treatment of pancreatic cancer treatment, yet their efficacy remains poor because of the adaptation of cancer cells to high concentration of ROS. Cells cope with ROS by recognizing 8-oxoguanine residues and processing severely oxidized RNA, which make it feasible to improve the efficacy of ROS-modulating drugs in pancreatic cancer by targeting 8-oxoguanine regulators. Methods: Poly(rC)-binding protein 1 (PCBP1) was identified as a potential oncogene in pancreatic cancer through datasets of The Cancer Genome Atlas (TCGA) project and Gene Expression Omnibus (GEO). High-throughput virtual screening was used to screen out potential inhibitors for PCBP1. Computational molecular dynamics simulations was used to verify the stable interaction between the two compounds and PCBP1 and their structure-activity relationships. In vitro experiments were performed for functional validation of silychristin. Results: In this study, we identified PCBP1 as a potential oncogene in pancreatic cancer. By applying high-throughput virtual screening, we identified Compound 102 and Compound 934 (silychristin) as potential PCBP1 inhibitors. Computational molecular dynamics simulations and virtual alanine mutagenesis verified the structure-activity correlation between PCBP1 and the two identified compounds. These two compounds interfere with the PCBP1-RNA interaction and impair the ability of PCBP1 to process RNA, leading to intracellular R loop accumulation. Compound 934 synergized with ROS agent hydrogen peroxide to strongly improve induced cell death in pancreatic cancer cells. Discussion: Our results provide valuable insights into the development of drugs that target PCBP1 and identified promising synergistic agents for ROS-modulating drugs in pancreatic cancer.
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NF-κB signaling is active in more than 50% of patients with pancreatic cancer and plays an important role in promoting the progression of pancreatic cancer. Revealing the activation mechanism of NF-κB signaling is important for the treatment of pancreatic cancer. In this study, the regulation of TNFα/NF-κB signaling by VRK2 (vaccinia-related kinase 2) was investigated. The levels of VRK2 protein were examined by immunohistochemistry (IHC). The functions of VRK2 in the progression of pancreatic cancer were examined using CCK8 assay, anchorage-independent assay, EdU assay and tumorigenesis assay. The regulation of VRK2 on the NF-κB signaling was investigated by immunoprecipitation and invitro kinase assay. It was discovered in this study that the expression of VRK2 was upregulated in pancreatic cancer and that the VRK2 expression level was significantly correlated with the pathological characteristics and the survival time of patients. VRK2 promoted the growth, sphere formation and subcutaneous tumorigenesis of pancreatic carcinoma cells as well as the organoid growth derived from the pancreatic cancer mouse model. Investigation of the molecular mechanism indicated that VRK2 interacts with IKKß, phosphorylating its Ser177 and Ser181 residues and thus activating the TNFα/NF-κB signaling pathway. An IKKß inhibitors abolished the promotive effect of VRK2 on the growth of organoids. The findings of this study indicate that VRK2 promotes the progression of pancreatic cancer by activating the TNFα/NF-κB signaling pathway, suggesting that VRK2 is a potential therapeutic target for pancreatic cancer.
Asunto(s)
Quinasa I-kappa B , Neoplasias Pancreáticas , Animales , Carcinogénesis , Humanos , Quinasa I-kappa B/genética , Quinasa I-kappa B/metabolismo , Ratones , FN-kappa B/metabolismo , Neoplasias Pancreáticas/genética , Fosforilación , Proteínas Serina-Treonina Quinasas , Transducción de Señal/genética , Factor de Necrosis Tumoral alfa/metabolismo , Neoplasias PancreáticasRESUMEN
This study investigated the inhibition mechanism of root growth in wheat seedlings when exposed to different zinc (Zn) concentrations. All applied Zn concentration did not affect seed germination, but reduced root length; in contrast, only Zn at 3mM inhibited significantly the growth of shoot. The loss of cell viability and the significant increases of lignification as well as the increases of hydrogen peroxide (H(2)O(2)), superoxide radical (O(2)(-)) and malondialdehyde levels were observed in the root tissue exposed to Zn treatment. And also, Zn stress led to the inhibition of cell-wall bound peroxidase. Moreover, NADPH oxidase inhibitor diphenylene iodonium could block greatly the elevation of O(2)(-) generation in Zn-treated roots. Therefore, the increased H(2)O(2) generation was dependent on the extracellular O(2)(-) production derived from plasma membrane NADPH oxidase. In addition, the loss of cell viability and the significant increases of lignification in response to the highest Zn concentration may be associated with the remarkable reduction of root growth in wheat seedlings.