scholarly journals Downregulated adaptor protein p66Shcmitigates autophagy process by low nutrient and enhances apoptotic resistance in human lung adenocarcinoma A549 cells

FEBS Journal ◽  
2013 ◽  
Vol 280 (18) ◽  
pp. 4522-4530 ◽  
Author(s):  
Zhichao Zheng ◽  
Jie Yang ◽  
Dan Zhao ◽  
Dan Gao ◽  
Xiaojie Yan ◽  
...  
Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1190 ◽  
Author(s):  
Hiroaki Eguchi ◽  
Toshiyuki Matsunaga ◽  
Satoshi Endo ◽  
Kenji Ichihara ◽  
Akira Ikari

Claudins (CLDNs) play crucial roles in the formation of tight junctions. We have reported that abnormal expression of CLDN2 confers chemoresistance in the spheroids of human lung adenocarcinoma A549 cells. A food composition, which can reduce CLDN2 expression, may function to prevent the malignant progression. Here, we found that ethanol extract of Brazilian green propolis (EBGP) and kaempferide, a major component of EBGP, decrease CLDN2 expression. In the two-dimensional culture model, EBGP decreased the tight junctional localization of CLDN2 without affecting that of zonula occludens-1, an adaptor protein, and enhanced paracellular permeability to doxorubicin, a cytotoxic anticancer drug. EBGP reduced hypoxic stress, and enhanced the accumulation and sensitivity of doxorubicin in the spheroid of A549 cells. Kaempferide dose-dependently decreased CLDN2 expression, although dihydrokaempferide and pinocembrin did not. The phosphorylation of Akt, a regulatory factor of CLDN2 expression, was inhibited by kaempferide but not by dihydrokaempferide. The 2,3-double bond in the C ring may be important to inhibit Akt. Kaempferide decreased the mRNA level and promoter activity of CLDN2, indicating that it inhibits the transcription of CLDN2. In accordance with EBGP, kaempferide decreased the tight junctional localization of CLDN2 and increased a paracellular permeability to doxorubicin, suggesting that it diminished the paracellular barrier to small molecules. In addition, kaempferide reduced hypoxic stress, and enhanced the accumulation and sensitivity of doxorubicin in the spheroids. In contrast, dihydrokaempferide did not improve the sensitivity to doxorubicin. Further study is needed using an animal model, but we suggest that natural foods abundantly containing kaempferide are candidates for the prevention of the chemoresistance of lung adenocarcinoma.


BioChem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 107-121
Author(s):  
Nghia Trong Vo ◽  
Eiichi Kusagawa ◽  
Kaori Nakano ◽  
Chihiro Moriwaki ◽  
Yasunobu Miyake ◽  
...  

Ostruthin (6-geranyl-7-hydroxycoumarin) is one of the constituents isolated from Paramignya trimera and has been classified as a simple coumarin. We recently reported the synthesis of alkyl triphenylphosphonium (TPP) derivatives from ostruthin and evaluated their anticancer activities. In the present study, we demonstrated that alkyl TPP ostruthin derivatives inhibited the up-regulation of cell-surface intercellular adhesion molecule-1 (ICAM-1) in human lung adenocarcinoma A549 cells stimulated with tumor necrosis factor-α (TNF-α) without affecting cell viability, while ostruthin itself exerted cytotoxicity against A549 cells. The heptyl TPP ostruthin derivative (termed OS8) attenuated the up-regulation of ICAM-1 mRNA expression at concentrations higher than 40 µM in TNF-α-stimulated A549 cells. OS8 inhibited TNF-α-induced nuclear factor κB (NF-κB)-responsive luciferase reporter activity at concentrations higher than 40 µM, but did not affect the translocation of the NF-κB subunit RelA in response to the TNF-α stimulation at concentrations up to 100 µM. A chromatin immunoprecipitation assay showed that OS8 at 100 µM prevented the binding of RelA to the ICAM-1 promoter. We also showed that OS8 at 100 µM inhibited the TNF-α-induced phosphorylation of RelA at Ser 536. Moreover, the TNF-α-induced phosphorylation of an inhibitor of NF-κB α and extracellular signal-regulated kinase was reduced by OS8. These results indicate that OS8 has potential as an anti-inflammatory agent that targets the NF-κB signaling pathway.


2007 ◽  
Vol 6 (1) ◽  
pp. 75 ◽  
Author(s):  
Dong-Cheol Seo ◽  
Ji-Min Sung ◽  
Hee-Jung Cho ◽  
Hee Yi ◽  
Kun-Ho Seo ◽  
...  

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