scholarly journals PLAUR Confers Resistance to Gefitinib Through EGFR/P-AKT/Survivin Signaling Pathway

2018 ◽  
Vol 47 (5) ◽  
pp. 1909-1924 ◽  
Author(s):  
Jian Zhou ◽  
Kwang Joo Kwak ◽  
Zuoren Wu ◽  
Dawei Yang ◽  
Jing Li ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Membrane Potential ◽  
Tyrosine Kinase ◽  
Lung Adenocarcinoma ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
Human Lung ◽  
Nsclc Patients ◽  
Gefitinib Resistance

Background/Aims: Tyrosine kinase inhibitor gefitinib significantly improves the survival of patients with non-small-cell lung cancer (NSCLC) by inhibiting epidermal growth factor receptor (EGFR) tyrosine kinase. However, patients eventually develop resistance to gefitinib through uncharacterized mechanisms. It is known that plasminogen activator urokinase receptor (PLAUR) plays an important role in cell proliferation, migration and apoptosis. However, the role of PLAUR, particularly exosomal PLAUR in gefitinib resistance in NSCLC has not been reported. The aim of this study is to determine the relationship between PLAUR and gefitinib resistance. Methods: In this study, a tethered cationic lipoplex nanoparticle (TCLN) biochip containing molecular beacons was used as probes to detect PLAUR mRNA in plasma exosomes from patients with gefitinib-sensitive and -resistant NSCLC. In vitro, Real-time PCR was used to examine the expression of PLAUR mRNA and Western blot was applied to examine the expression of related proteins. The gene knockdown was achieved by Lentivirus based RNA silence technique. The cell counting kit-8 assay and EdU incorporation were used to examine cell proliferation. The flow cytometry was applied to determine cell apoptosis and cell cycle, while the mitochondrial membrane potential was measured by JC-1 dye assay. Signaling pathway affected by PLAUR knockdown was identified by cDNA Microarray. The effect of PLAUR knockdown on tumorigenesis was analyzed in vivo. Results: We found that the exosomal PLAUR mRNA in the plasma of gefitinib-resistant NSCLC patients was significantly increased compared to that of gefitinib-sensitive NSCLC patients. The PLAUR mRNA and soluble PLAUR protein were also significantly increased in gefitinib-resistant human lung adenocarcinoma PC9R cells compared to gefitinib-sensitive PC9 cells. Silencing PLAUR in PC9R cells impaired mitochondrial membrane potential and increased cell apoptosis via EGFR/p-AKT/survivin signaling pathway. Furthermore, EGFR was upregulated in the geftinib-resistant PC9R cells, and knockdown of EGFR significantly increased cell apoptosis. Conclusions: Taken together, our results demonstrated that PLAUR induces geftinib-resistance through EGFR/p-AKT/survivin signaling pathway in gefitinib-resistant human lung adenocarcinoma cells. PLAUR could be a novel therapeutic target for gefitinib-resistant NSCLC patients.

Effect and Mechanism of Interferon-Gamma Combined with Pembrolizumab on Chemoresistance of Lung Adenocarcinoma

2020 ◽  
Vol 10 (1) ◽  
pp. 105-109
Author(s):  
Chunling Peng ◽  
Chunqian Feng ◽  
Sha Feng ◽  
Daiqiang Li
Keyword(s):  
Lung Cancer ◽  
Cell Proliferation ◽  
Western Blot ◽  
Lung Adenocarcinoma ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Drug Resistant ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Resistant Cells

Tumor microenvironment can lead to chemotherapy resistance in lung cancer. PD-1 and PD-L1 are core regulatory molecules of immune checkpoint. Our study intends to assess IFN-γ combined with Pembrolizumab’s effect on chemoresistance of lung adenocarcinoma. Human A549/DDP lung adenocarcinoma resistant strains were cultured in vitro and randomly divided into control group, IFN-γ group and Pembrolizumab+IFN-γ group followed by analysis of cell proliferation by MTT assay, cell apoptosis by flow cytometry, the levels of PD-L1 and Bcl-2 by Western Blot, the level of interleukin-10 (IL-10) and IL-17 by ELISA, as well as the expression of JAK/STAT3 signaling pathway by Western Blot. IFN-γ-treated A549/DDP cells showed significantly inhibited cell apoptosis, promoted cell proliferation, increased level of IL-10, IL-17, and elevated expression of PD-L1 and Bcl-2, as well as increased phosphorylation of JAK and STAT3 (P < 0.05). However, Pembrolizumab combined with IFN-γ treatment significantly inhibited cell proliferation, increased cell apoptosis, decreased IL-10 and IL-17 level, PD-L1 and Bcl-2 expression as well as JAK and STAT3 phosphorylation with significant difference compared to IFN-γ treatment alone (P < 0.05). IFN-γ up-regulates PD-L1 expression by up-regulating the JAK/STAT3 pathway, inhibits the apoptosis of drug-resistant cells in lung adenocarcinoma, and promotes cell proliferation. Pembrolizumab can reverse IFN-γ’s effect on drug-resistant cells of lung adenocarcinoma, down-regulate JAK/STAT3 signaling pathway and, promote the apoptosis of drug-resistant lung cancer cells, and inhibit cell proliferation.

scholarly journals Artemisinin attenuated oxidative stress and apoptosis by inhibiting autophagy in MPP+-treated SH-SY5Y cells

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Protein Expression ◽  
Mitochondrial Membrane Potential ◽  
Western Blotting ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Neuroprotective Effect ◽  
Neuroprotective Effects

Abstract Background Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. The oxidative stress is an important component of the pathogenesis of PD. Artemisinin (ART) has antioxidant and neuroprotective effects. The purpose of this study is to explore the neuroprotective effect of ART on 1-methyl-4-phenyliodine iodide (MPP +)-treated SH-SY5Y cells and underlying mechanism. Methods We used MPP+-treated SH-SY5Y cells to study the neuroprotective effect of ART. Cell viability was measured by MTT assay after incubating the cells with MPP+ and/or ART for 24 h. DCFH-DA was used to detect the level of intracellular reactive oxygen species (ROS), and WST-8 was used to detect the level of superoxide dismutase (SOD). The level of intracellular reduced glutathione (GSH) was detected with 5,5΄-dithiobis-(2-nitrobenzoic acid), and the level of malondialdehyde (MDA) was assessed based on the reaction of MDA and thiobarbituric acid. A mitochondrial membrane potential detection kit (JC-1) was used to detect changes in the mitochondrial membrane potential (MMP), and an Annexin V-FITC cell apoptosis kit was used to detect cell apoptosis. The expression levels of caspase-3, cleaved caspase-3 and the autophagy-related proteins LC3, beclin-1, and p62 were detected by Western blotting. In addition, to verify the change in autophagy, we used immunofluorescence to detect the expression of LC3 and p62. Results No significant cytotoxicity was observed at ART concentrations up to 40 μM. ART could significantly increase the viability of SH-SY5Y cells treated with MPP+ and reduce oxidative stress damage and apoptosis. In addition, the Western blotting and immunofluorescence results showed that MPP+ treatment could increase the protein expression of beclin1 and LC3II/LC3I and decrease the protein expression of p62, indicating that MPP+ treatment could induce autophagy. Simultaneous treatment with ART and MPP+ could decrease the protein expression of beclin1 and LC3II/LC3I and increase the protein expression of p62, indicating that ART could decrease the level of autophagy induced by MPP+. Conclusion Our results indicate that ART has a protective effect on MPP+-treated SH-SY5Y cells by the antioxidant, antiapoptotic activities and inhibition of autophagy. Our findings may provide new hope for the prevention and treatment of PD.

scholarly journals Kaempferol inhibits proliferation, migration, and invasion of liver cancer HepG2 cells by down-regulation of microRNA-21

2018 ◽  
Vol 32 ◽  
pp. 205873841881434 ◽  
Author(s):  
Genglong Zhu ◽  
Xialei Liu ◽  
Haijing Li ◽  
Yang Yan ◽  
Xiaopeng Hong ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Liver Cancer ◽  
Signaling Pathway ◽  
Hepg2 Cell ◽  
Cell Apoptosis ◽  
Hepg2 Cells ◽  
Mtor Signaling ◽  
Brdu Incorporation ◽  
Migration And Invasion ◽  
Mtor Signaling Pathway

Liver cancer is one of the most common and lethal cancers in human digestive system, which kills more than half a million people every year worldwide. This study aimed to investigate the effects of kaempferol, a flavonoid compound isolated from vegetables and fruits, on hepatic cancer HepG2 cell proliferation, migration, invasion, and apoptosis, as well as microRNA-21 (miR-21) expression. Cell viability was detected using cell counting kit-8 (CCK-8) assay. Cell proliferation was measured using 5-bromo-2′-deoxyuridine (BrdU) incorporation assay. Cell apoptosis was assessed using Guava Nexin assay. Cell migration and invasion were determined using two-chamber migration (invasion) assay. Cell transfection was used to change the expression of miR-21. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyze the expressions of miR-21 and phosphatase and tensin homologue (PTEN). Expression of key proteins involved in proliferation, apoptosis, migration, invasion, and phosphatidylinositol 3-kinase/protein kinase 3/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway were evaluated using western blotting. Results showed that kaempferol significantly inhibited HepG2 cell proliferation, migration, and invasion, and induced cell apoptosis. Kaempferol remarkably reduce the expression of miR-21 in HepG2 cells. Overexpression of miR-21 obviously reversed the effects of kaempferol on HepG2 cell proliferation, migration, invasion, and apoptosis. Moreover, miR-21 negatively regulated the expression of PTEN in HepG2 cells. Kaempferol enhanced the expression of PTEN and inactivated PI3K/AKT/mTOR signaling pathway in HepG2 cells. In conclusion, kaempferol inhibited proliferation, migration, and invasion of HepG2 cells by down-regulating miR-21 and up-regulating PTEN, as well as inactivating PI3K/AKT/mTOR signaling pathway.

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