Detection of expressing of miR-103/KLF4 in A549 lung cancer cells and A549/DDP resistant cells and validation of the targeted relationship / 中国医师杂志

Objective To study the expression and targeted relationship of miR-103/KLF4 (Krüppel like factor) in A549 and resistant cell lines of lung cancer.Methods To culture the A549 cell lines and A549/DDP (cisplatin) resistant cell lines in vitro and detect survival rates by methyl thiazolyl tetrazolium (MTT) method.Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to test the expression of miR-103/KLF4 of these cell lines.Dual-luciferase reporter gene experiment to detect the targeted relationship.Results A higher expression of miR-103 and a obvious lower expression of KLF4 were observed in A549/DDP resistant cell lines.MiR-103 target KLF4-3'UTR (3'untranslated regions) directly in lung cancer cells.Conclusions In A549/DDP resistant cells,miR-103 can regulate KLF4 at target.

Examination of the expressions of miR-221 in the human pulmonary fibrosis tissues and in A549 cells treated with TGFβ1 / 中国医师杂志

Objective To investigate the expressions of microRNA-221 (miR-221) in the human pulmonary fibrosis tissues and in adenocarcinoma(A549) cells treated with transforming growth factor beta 1 (TGFβ1).Methods Real time-PCR was used to detect the expressions of miR-221 in pathologically diag nosed as pulmonary fibrosis tissue and in A549 cells treated with TGFβ1.Results miR-221 in pulmonary fibrosis tissue was downregulated compared to normal tissues (P ＜ 0.05).The morphology of cells was changed from long spindle type to short, the number of cells was increased, and the adjacent cells were not connected closely.TGFβ1, N-cadherin, vimentin, α-smooth muscle actin (α-SMA), collagen Ⅰ, and collagen Ⅲ levels were higher, whereas E-cadherin level was lower in TGFβ1-treated group compared to the control group.miR-221 expression was downregulated in cells after TGFβ1 treatment (P ＜ 0.05).Conclusions miR-221 was downregulated in pulmonary fibrosis tissues and in A549 cells, which indicates that miR-221 may play an important role in the formation of pulmonary fibrosis.

NDRG1 suppresses TGF-β-induced epithelial-mesenchymal transition in lung cancer A549 cells / 中国医师杂志

Objective To explore the effect and molecular mechanism of N-myc downstream regulated gene 1 (NDRG1) on transforming growth factor-beta (TGF-β)-induced epithelial-mesenchymal transition (EMT) in human lung cancer cells.Methods Lung cancer A549 cells were transfected with NDRG1 overexpressed vector,and then treated with 5 μg/L TGF-β1.The abilities of invasion were detected by Transwell assay.The expressions of NDRG1 mRNA and protein were analyzed by teal-time reverse transcription polymerase chain reaction (RT-PCR) were examined with Western blot.The expressions of EMT-associated markers E-cadherin and Vimentin,and EMT-associated signaling molecules Snail,AKT and Smad were detected with Western blot.Results We found that TGF-β1 treatment could induce morphological alteration of A549 cells from epithelial morphology to mesenchymal morphology.TGF-β1 significantly increased the migration of A549 cells,and increased the expression of mesenchymal maker vimentin and decreased epithelial marker E-cadherin.More importantly,overexpression of NDRG1 significandy reversed the effects of TGF-β1 on A549 cells.Moreover,NDRG1 significandy decreased the levels of phospho-AKT,and suppressed the expression of EMT-related transcription factor Snail.Conclusions NDRG1 could reverse the effects of TGF-β1 on EMT in A549 cells,by which mechanism is related to reduction of the expressions of phospho-AKT and Snail.