Background: Chemotherapy remains a primary treatment method for advanced pancreatic cancer. However, chemotherapy resistance can influence the therapeutic effect of pancreatic cancer. The resistance mechanism of chemotherapeutic agents such as gemcitabine, which is an agent typically used to treat pancreatic cancer, is complicated and can be influenced by genes and the environment. Oridonin is a tetracyclic diterpenoid compound extracted from the traditional Chinese herb Rabdosia labtea . Oridonin may overcome drug resistance in pancreatic cancer, but researching pancreatic cancer drug resistance of chemotherapy by oridonin is not completely understood. Purpose: The present study aimed to assess the impact of oridonin on multidrug resistance proteins, apoptosis-associated proteins and energy metabolism in gemcitabine-resistant PANC-1 (PANC-1/Gem) pancreatic cancer cells. Methods: Gemcitabine resistance in PANC-1/Gem cells was induced using a concentration gradient of gemcitabine. Cell Counting Kit-8 assays were used to detect the impact of gemcitabine and oridonin on the proliferation of PANC-1 and PANC-1/Gem cells. Western blot analysis and immunofluorescence were used to detect the expression of multidrug resistance proteins, apoptosis-associated proteins and low-density lipoprotein receptor protein 1 (LRP1) proteins in PANC-1/Gem cells. The effects of gemcitabine and oridonin on PANC-1/Gem cells apoptosis were detected using flow cytometry. Animal xenograft tumor assays were used to detect the effect of gemcitabine and oridonin on pancreatic cancer in vivo. Furthermore, the ATP Assay kit was used to determine the effects of gemcitabine and oridonin on ATP levels in PANC-1/Gem cells. Immunofluorescence assays were used to detect the effects of gemcitabine and oridonin on the expression of low-density lipoprotein receptor protein 1 (LRP1) in PANC-1/Gem cells. In addition, LRP1 expression was knocked down in PANC-1/Gem cells via lentiviral vector-mediated RNA silencing. Clone formation assays and Western blot analysis were used to detect the effect of LRP1 knockdown on the proliferation of PANC-1/Gem cells. Results: The present results demonstrate that oridonin overcomes PANC-1/Gem cells gemcitabine reistance by regulating GST pi and LRP1/ERK/JNK signaling. Conclusion: In conclusion, the present study indicated that oridonin could overcome gemcitabine resistance in PANC-1/Gem cells by regulating GST pi and LRP1/ ERK/JNK signaling, inducing cell apoptosis. Therefore, oridonin with gemcitabine may be a promising preoperative treatment for patients who suffer from pancreatic cancer.
Circulating immune complexes (CICs) are produced during the immune response. It is more clinically important to establish a general and efficient CICs dissociation technique for the detection of antigens for CICs other than the detection of free antigens in the serum. Polyethylene glycol (PEG) two-precipitation separation and glycine-HCl as a buffer system were employed to develop a general and efficient buffer dissociation technique to separate CICs from serum and dissociate antigens from CICs. The measurement value of new PEG two-precipitation separation technique was higher than traditional PEG precipitation separation technique. There were slight differences in the dissociation conditions of HCV Core-IC, HIV P24-IC, Ins-IC and TG-IC as compared to HBsAg-IC. The detection of antigens in HBsAg-IC, HCV Core-IC, HIV P24-IC, Ins-IC and TG-IC with this technique was superior to that with HCl Dissociation, Trypsin Digestion or Immune Complex Transfer technique. PEG two-precipitation dissociation technique may reduce macromolecular protein and the adhesion of free antigens during the co-precipitation, which increases the efficiency of separation and precipitation of CICs. This technique also avoids the damage of reagents to antigens, assuring the repeatability, reliability and validity. Thus, this technique is application in samples negative or positive for free antigens.
Recent studies have demonstrated that the expression of the long non-coding RNA (lncRNA) AFAP1-AS1 in pancreatic cancer is negatively correlated with survival and prognosis. However, the effects of oridonin and lncRNA AFAP1-AS1 on the epithelial-to-mesenchymal transition (EMT) and migration of pancreatic cancer cells have not been fully elucidated. Surgery is the only potentially curative method for pancreatic cancer, but postoperative recurrence and metastasis are common. The aim of the present study was to assess the effect of oridonin and lncRNA AFAP1-AS1 silencing on pancreatic cancer cells. The pancreatic cancer cell lines BxPC-3 and PANC-1 cells were transfected with siAFAP1-AS1 and its negative control (siNC). After that, oridonin was used to treat the siAFAP1-AS1-transfected cells. The expression of lncRNA AFAP1-AS1 was downregulated in the pancreatic cancer cell lines BxPC-3 and PANC-1. The apoptosis and cell cycle progression of pancreatic cancer cells were evaluated by flow cytometry and Hoechst 33258 staining. Metastasis and invasion of BxPC-3 and PANC-1 cells were detected by transwell migration assay, real-time cell analysis, and western blot analysis. Cells were transfected with the lentiviral siAFAP1-AS1 and siNC, and tumorigenesis was evaluated in BALB/C nude mice. Immunohistochemical examination was used to verify the effects of oridonin and siAFAP1-AS1 on pancreatic cancer. The results demonstrated that the combination of oridonin and siAFAP1-AS1 inhibited pancreatic cancer cell proliferation, induced apoptosis, arrested cell cycle progression, prevented the migration, regulated EMT-related protein expression in BxPC-3 and PANC-1 cells, and inhibited pancreatic cancer cell tumorigenicity and EMT in nude mice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.