ABSTRACT
OBJECTIVE@#To explore the effect of dihydromyricetin on the expression of miR-98-5p and its mechanism in the development of Herceptin resistance in SKBR3 cells.@*METHODS@#The expression of IGF2 and miR-98-5p and their interaction relationship were analyzed by bioinformatics analysis through TargetScan online databases. SKBR3 cells and drug-resistant SKBR3-R cells were cultured in cell experiments. Xenograft tumor mice were constructed by SKBR3 and SKBR3-R cells. Proteins were detected by western blotting and immunohistochemistry. Transfected cells were constructed by shRNA lentivirus vectors. RT-QPCR was used to detect RNA. Cell proliferation was detected by MTS method. Cell jnvasion was detected by Transwell assay. Luciferase reporting assays were used to verify RNA interactions. IGF-1R/HER2 heterodimer was determined by immunocoprecipitation.@*RESULTS@#The expression of IGF2, p-IGF1R, p-Akt and p-S6K in SKBR3-R cells were significantly higher than those in SKBR3 cells, while the expression of PTEN protein was lower in SKBR3-R cells (P < 0.05). IGF1R/HER2 heterodimer in SKBR3-R cells was significantly increased (P < 0.01).The expression of IGF2 and invasion ability were significantly reduced while transfected with miR-98-5p in SKBR3-R cells (P < 0.05), but the IGF2 mRNA were no difference in both cells (P > 0.05). The expression of miR-98-5p was up-regulated and IGF2 was decreased in drug-resistant xenograft tumor mice after feeding with dihydromyricetin, and the tumor became more sensitivity to Herceptin (P < 0.05).@*CONCLUSION@#Dihydromyricetin could induce the expression of miR-98-5p, which binds to IGF2 mRNA to reduce IGF2 expression, inhibit the IGF-1R/HER2 formation, thereby reversing cell resistance to Herceptin in SKBR3-R cells.
Subject(s)
Animals , Humans , Mice , Cell Line, Tumor , Flavonols/pharmacology , MicroRNAs/metabolism , Receptor, IGF Type 1 , TrastuzumabABSTRACT
Objective:To investigate the effects of long non-coding RNA (lncRNA) CDKN2B-AS1 targeting miR-98-5p on proliferation and invasion of lung cancer A549 cells.Methods:A549 cells cultured in vitro were divided into control group, pcDNA group (transfected with pcDNA) , CDKN2B-AS1 group (transfected with pcDNA CDKN2B-AS1) and double transfection group (transfected with pcDNA CDKN2B-AS1 and pcDNA miR-98-5p) . The expression of lncRNA CDKN2B-AS1, miR-98-5p and the protein expression of PCNA, MMP-9 in A549 cells were detected. The activity, clone number, cloning efficiency, and the number of invasive cells of A549 cells were detected.Results:Compared with pcDNA group, the expression level of lncRNA CDKN2B-AS1 [ (2.14±0.14) vs (1.03±0.10) ], OD value in each time points, clone number [ (314.60±18.13) vs (220.08±12.46) ], cloning efficiency [ (85.81±3.06) % vs (60.03±2.85) %], invasive cell number [ (233.30±18.98) vs (140.84±12.30) ], expression levels of PCNA [ (0.78±0.08) vs (0.48±0.07) ] and MMP-9 [ (0.75±0.06) vs (0.38±0.06) ] proteins in A549 cells in CDKN2B-AS1 group were significantly increased ( P<0.05) ; the expression level of miR-98-5p [ (0.23±0.03) vs (0.99±0.09) ] was significantly decreased ( P<0.05) ; compared with CDKN2B-AS1 group, there was no significant difference in the expression level of lncRNA CDKN2B-AS1 in A549 cells in double transfection group ( P>0.05) , while the expression level of miR-98-5p in A549 cells was significantly increased ( P<0.05) . The OD value in each time points, clone number, cloning efficiency, invasive cell number, expression levels of PCNA and MMP-9 proteins were significantly decreased ( P<0.05) . Conclusion:LncRNA CDKN2B-AS1 can promote the proliferation and invasion of lung cancer A549 cells by targetingly inhibiting the expression of miR-98-5p.