Dihydromyricetin reverses Herceptin resistance by up-regulating miR-98-5p and inhibiting IGF1R/HER2 dimer formation in SKBR3 cells / 南方医科大学学报

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.

Effects of lncRNA CDKN2B-AS1 targeting miR-98-5p on proliferation and invasion of lung cancer A549 cells / 中华内分泌外科杂志

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.

Expression and Action Mechanism of miR-98 in Colon Cancer Tissues / 中国医科大学学报

Objective To investigate the expression and action mechanism of miR-98 in colon cancer tissues. Methods Tumor tissues and adjacent tissues were collected from 40 patients with colorectal cancer. The expression of miR-98 in tumor tissues and adjacent tissues was detected by real-time PCR. miR-98 was overexpressed or silenced in cells,and the effects on proliferation,cell cycle,and apoptosis were analyzed using MTT,flow cytometry,and Hoechst 33258 assays. Results Real-time PCR showed that the expression of miR-98 in tumor tissues was lower than that in adjacent tissues (P = 0.022). The survival rate of patients with lower miR-98 expression was shorter than that of patients with higher miR-98 expression. The MTT assay showed that miR-98 overexpression inhibited the proliferation of HCT116 cells. Hoechst 33258 staining showed that the overexpression of miR-98 could inhibit the cell cycle and promote the apoptosis of HCT116 cells. Conclusion miR-98 can inhibit the proliferation and promote the apoptosis of colon cancer cells. The expression of miR-98 is closely related to the survival of patients with colon cancer.

The expression and clinical significance of miR-98 in peripheral blood mononuclear cells in asthmatic children / 中国小儿急救医学

Objective To explore the role of miR-98 in peripheral blood mononuclear cells (PBMC) in the pathogenesis and development of childhood asthma.Methods A total of 43 cases of asthmatic children and 30 cases of healthy controls were enrolled in the study.Peripheral blood mononuclear cells were isolated in both healthy subjects and asthmatic children in acute attack and remission stages.The expressions of miR-98 and interleukin-4(IL-4) and IL-13 mRNA were detected by real-time quantitative PCR.Results The miR-98 levels of asthmatic children in attack stage were significantly lower than those in remission stage and control group (P0.05).Furthermore,a negative correlation was found between the expression of miR-98 and IL-5(r=-0.794,P<0.01) and between the expression of miR-98 and IL-13 mRNA (r=-0.804,P<0.01) in asthmatic children in attack stage.A positive correlation was also found between IL-4 and IL-13 mRNA in asthmatic children in attack stage (r=0.853,P<0.01).Conclusion The expression of miR-98 decreased in asthmatic children,and miR-98 might be involved in the pathogenesis and development of asthma.

MicroRNA-98 inhibits the cell proliferation of human hypertrophic scar fibroblasts via targeting Col1A1

BACKGROUND: Hypertrophic scarring (HS) is a severe disease, and results from unusual wound healing. Col1A1 could promote the hypertrophic scar formation, and the expression of Col1A1 in HS tissue was markedly higher than that in the normal. In present study, we aimed to identify miRNAs as post-transcriptional regulators of Col1A1 in HS. METHODS: MicroRNA-98 was selected as the key miRNA comprised in HS. The mRNA levels of miR-98 in HS tissues and the matched normal skin tissues were determined by qRT-PCR. MTT and flow cytometry were used to determine the influence of miR-98 on cell proliferation and apoptosis of HSFBs, respectively. Col1A1 was found to be the target gene of miR-98 using luciferase reporter assay. Luciferase assay was performed to determine the relative luciferase activity in mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor with Col1A13'-UTR wt or Col1A13'-UTR mt reporter plasmids. The protein expression of Col1A1 in HSFBs after transfection with mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor were determined by western blotting. RESULTS: The mRNA level of miR-98 in HS tissues was much lower than that in the control. Transfection of HSFBs with a miR-98 mimic reduced the cell viability of HSFBs and increased the apoptosis portion of HSFBs, while inhibition of miR-98 increased cell viability and decreased apoptosis portion of HSFBs. miR-98 inhibitor increased the relative luciferase activity significantly when cotransfected with the Col1A1-UTR reporter plasmid, while the mutant reporter plasmid abolished the miR-98 inhibitor-mediated increase in luciferase activity. Western blotting revealed that overex-pression of miR-98 decreased the expression of Col1A1. CONCLUSIONS: Overexpression of miR-98 repressed the proliferation of HSFBs by targeting Col1A1.

CCL18 downregulates the expression of miR98 in breast cancer cells via N-Ras/c-myc/lin28 pathway / 西安交通大学学报(医学版)

Objective To explore whether CCL18 is involved in regulating the expression of miRNAs in breast cancer.Methods The expression profile of miRNAs in the breast cancer cell following CCL18 treatment was determined by miRNAs microarray analysis.Then we performed QRT-PCR and Luciferase Reporter Assay to validate the results from the miRNAs microassay.We used transient transfection to change the expression of miR98 and c-myc in breast cancer cells.We then used QRT-PCR and Western blot to analyze the mechanism by which CCL18 downregulates the expression of miR98 in breast cancer cells.Results miRNAs microarray analysis showed that cells treated with CCL18 differentially expressed 20 miRNAs genes compared with those in the control group. Our QRT-PCR and Luciferase Reporter Assay confirmed the result.The mRNA and protein expressions of C-myc and lin28 were increased after CCL18 stimulation in breast cancer cells.Transfection with c-myc siRNAs rescued the increase of lin28 and loss of miR98 expression caused by CCL18 stimulation.Our results also showed that CCL18 could upregulate the expression of N-Ras at post-transcription level.Conclusion CCL18 downregulates the expression of miR98 via N-Ras/c-myc/lin28 pathway.The downregulated miR98 increases the expression of N-Ras after transfection,which further activates c-myc/lin28 pathway and forms a positive feedback loop.