ABSTRACT
Objective To investigate the regulation of miR-939-5p on USP22 gene expression and its effect on liver cancer migration and proliferation.Methods The expression of miR-939-5p in hepatoma cell lines (HepG2,MHCC-97H,SMMC-7721,BEL-7404 and Huh7) and normal liver cell line LO2 was detected by realtime PCR (qPCR).The liver cancer cells with the lowest expression were used as experimental subjects,and transfected with miR-939-5p (Experimental group) or miR-NC (Control group).qPCR was used to detect the transfection efficiency of miR-939-5p.Transwell migration assay and MTT proliferation assay were used to detect the migration and proliferation of hepatoma cells after transfected miR-939-5p.Bioinformatics software predicted target genes for miR-939-5p.The dual luciferase reporter gene verified the interaction of miR-939-5p with the target gene.qPCR and Western blotting were used to detect the expression of target genes at mRNA and protein levels after over-expression of miR-939-5p.Measurement data were expressed as (Mean ± SD),and t test was used for comparison between groups.Results The expression of miR-939-5p was significantly lower in hepatoma cell lines than in normal hepatocytes (P ＜0.01),and the expression of miR-939-5p was the lowest in SMMC-7721 cells (P＜0.01).miR-939-5p was efficiently transfected into SMMC-7721 cells [(1.01 ±0.07) vs (20.12 ± 1.27),P ＜0.01].High expression of miR-939-5p inhibited the migration ability (P ＜ 0.01) and proliferative capacity of liver cancer SMMC-7721 cells (P ＜0.05).The USP22 gene may be a target gene of miR-939-5p.The luciferase reporter gene confirmed that miR-939-5p specifically binds to the 3'-UTR of USP22 mRNA (P ＜ 0.01).USP22 expression was decreased at mRNA and protein levels after high expression of miR-939-5p (P ＜ 0.01).Conclusions The expression of miR-939-5p was down-regulated in hepatocellular carcinoma cell lines,and miR-939-5p inhibited the migration and proliferation of liver cancer SMMC-7721 cells.The molecular mechanism was to interfere with the expression of USP22 gene.
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Objective To investigate the expression of USP22 in cervical cancer cells,and the effects of USP22 on cell proliferation and chemosensitivity to cisplatin in cervical cancer cells. Methods Quantitative real-time polymerase chain reaction(qRT-PCR)was conducted to detect the expression of USP22 mRNA in cervical cancer cells.Cell count kit-8,flow cytometry,and tumorigenesis were performed to detect the effects of USP22 on the proliferation,apoptosis,cycle cycle,and chemosensitivity of cervical cancer cells to cisplatin in vitro and in vivo. Results USP22 was upregulated in cervical cancer cells compared to human immortalized epidermal cells. Cell proliferation was inhibited,cell apoptosis was promoted,cell cycle was arrested in G1 stage and chemosensi-tivity to cisplatin was enhanced in cervical cancer cells transfected with USP22-siRNAs.Furthermore,tumorigene-sis assays proved tumor growth was inhibited and chemosensitivity to cisplatin was enhanced when USP22 was silenced in HeLa cells. Conclusion USP22 expression is upregulated in cervical cancer cells,and USP22 could promote cell proliferation and inhibit chemosensitivity to cisplatin in cervical cancer cells.
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Objective To investigate the effect and underlying mechanism of micro ribonucleic acid (miR)-101 on the epithelial-mesenchymal transition in human hepatocellular carcinoma MHCC97H cells. Methods MHCC97H cell lines were transfected with miR-101 mimics (M101 group) and negative control mimic (NCM group), and the cell lines without transfection were used as the control group. The expression levels of miR-101 in cells of 3 groups were quantitatively measured using reverse transcription polymerase chain reaction (RT-PCR). Transwell assay was performed to evaluate the cell migration and invasion ability of 3 groups. The expression levels of vimentin, α-catenin, E-cadherin and USP22 proteins in cells of 3 groups were measured by Western blot. The relationship between miR-101 and USP22 was analyzed by dual-luciferase assay. Results In the M101 group, the expression level of miR-101 was significantly up-regulated, which was approximately 761 times of that in the control group (P<0.05). In the M101 group, the quantity of migrating cells was 15.7±1.6, significantly lower than 94.1± 1.8 in the control group (P<0.05). In the M101 group, the quantity of invasive cells was 9.1±0.4, significantly lower compared with 51.6±0.9 in the control group (P<0.05). In the M101 group, the expression levels of vimentin and USP22 protein were significantly down-regulated, whereas the expression levels of α-catenin and E-cadherin protein were significantly up-regulated. Dual-luciferase assay revealed that USP22 was the target gene of the downstream miR-101 signaling pathway. Conclusions miR-101 regulates the expression of epithelial-mesenchymal transition-related proteins and suppresses the epithelial-mesenchymal transition of hepatocellular carcinoma MHCC97H cells probably through down-regulating the expression level of USP22.
ABSTRACT
Deubiquitylases remove ubiquitin moieties from different substrates to regulate protein activity and cell homeostasis .Since this posttranslational modification plays a role in several different cellular functions ,its deregulation has been associated with different pathologies .Aberrant expression of Ubiquitin -Specific Peptidase 22(USP22)has been associated with poor cancer prognosis .This article reviews the research status of USP 22.