Triptolide reverses epithelial-mesenchymal transition in glioma cells via inducing autophagy

Abstract

Background: To observe the effects of triptolide (TP) on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of glioma cells, and to explore the possible mechanisms of phenotypic changes in EMT.Methods: The U87 and U251 glioma cell lines were treated TP. The Cell Counting Kit-8 (CCK-8) method was used to detect the half-maximal inhibitory concentration (IC 50 ) of TP in these two cell lines and the inhibition of cell proliferation at the IC 50 concentration. The wound-healing experiment and Transwell invasion assay were used to detect the cells' migration and invasion abilities, respectively. Using western blot protocol, the expression levels of the EMT markers were analyzed, and the levels of the autophagy markers were also detected. The pEGFP-C2-LC3B plasmid was transfected into glioma cells, and the effect of TP on autophagy was detected by immunofluorescence. A subcutaneous tumor model in nude mice was established to observe the effect of TP on cell proliferation in vivo, and immunohistochemistry (IHC) was used to detect the expression levels of EMT markers in mouse tumor tissues.Results: TP significantly inhibited the proliferation of U87 and U251 cells in a dose-and time-dependent manner. TP had a significant inhibitory effect on the migration and invasion of U87 and U251 cells. Western blot showed that TP reversed the process of EMT in glioma cells, which was evidenced by the upregulated expression of the epithelial marker E-cadherin, and the downregulated expression of the mesenchymal markers N-cadherin, Vimentin, ZEB1, Snail, and Slug. TP increased autophagy in glioma cells, increased the LC3B II/I ratio, and upregulated Beclin-1 and Atg-7 expression. Immunofluorescence showed that the number of autophagosomes increased significantly after TP was applied to cells. In the nude mouse subcutaneous tumor model, experiments revealed an inhibitory effect of TP on glioma cell proliferation in vivo. IHC confirmed that the expression of E-cadherin was upregulated in mouse tumor tissues, while the expression levels of N-Cadherin and Vimentin were downregulated.Conclusions: TP can inhibit glioma cell proliferation, migration, and invasion, and reverse EMT progression. The possible mechanism of EMT reversal in glioma cells is that TP induces autophagy.

Gut Microbiome Alterations Affect Glioma Development and Foxp3 Expression in Tumor Microenvironment in Mice

“…At present, the main treatment for glioma is surgery combined with high-precision chemoradiotherapy and tumor treatment field (TTF) ( 3 ). Glioma has made advances in chemotherapy and surgery, but overall survival (OS) has not increased significantly, and the challenges of rapid spread, molecular heterogeneity, and drug delivery across the blood–brain barrier limit the therapy effectiveness ( 4 , 5 ). As immunotherapy is gradually applied to malignant tumors, the study of the tumor microenvironment and tumor–host interaction is helpful to develop new therapeutic strategies, which is an important direction to explore potential therapies for glioma ( 6 ).…”

Larotrectinib induces autophagic cell death through AMPK/mTOR signalling in colon cancer

“…Autophagy is a major process that contributes to the maintenance of intracellular energy metabolism and self‐survival 18 . Recently, it has been demonstrated that autophagy and EMT are tightly correlated in regulating tumorigenesis and tumour progression 19,20 . During the initial stage of tumour, autophagy suppresses cancer invasion and metastasis by selectively degrading important signalling molecules in the EMT process 19 .…”

“…18 Recently, it has been demonstrated that autophagy and EMT are tightly correlated in regulating tumorigenesis and tumour progression. 19,20 During the initial stage of tumour, autophagy suppresses cancer invasion and metastasis by selectively degrading important signalling molecules in the EMT process. 19 In contrast, during the process of tumour metastasis and diffusion, cancer cells need to activate autophagy to obtain sufficient energy and promote EMT.…”

Xiaotan Sanjie Decoction Inhibits Gastric Cancer Cell Proliferation, Migration, and Invasion through lncRNA-ATB and miR-200A

“…The tumor tissues were dissected and collected. Pathological examination and SABER-FISH were used to assess the expression of EMT related antibodies and the location of lncRNA-ATB in tissues [ 13 , 14 ].…”