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@#Objective: To investigate the effect of long non-coding RNA CDKN2B antisense RNA 1 (CDKN2B-AS1) on malignant biological behaviors of melanoma B16-F10 cells by targeting miR-7-5p. Methods: Melanoma B16-F10 cells were chosen for this study. shRNA CDKN2B-AS1 vector was constructed and transfected into B16-F10 cells. The experimental cells were divided into control group, sh-CDKN2B-AS1 group, miR-7-5p mimic group and miR-7-5p inhibitor group. The expression level of CDKN2B-AS1 mRNA in the transfected B16-F10 cells was detected by RT-PCR; the number of clone formation and the proliferation ability of the cells were detected by Clone formation assay and MTT assay; and the migration and invasion ability of the cells were detected by Scratch-healing assay and Transwell assay. The targeting relationship between CDKN2B-AS1 and miR-7-5p was detected by Luciferase reporter gene assay. The mRNA expression of miR-7-5p and protein expressions of Ki67, cleaved caspase-3, E-cadherin, N-cadherin and Twist1 in B16-F10 cells after transfection with miR-7-5p mimics/inhibitor were detected by RT-PCR and Western blotting, respectively. Results: Compared with the control group, the expression level of CDKN2B-AS1 mRNA in B16-F10 cells of sh-CDKN2B-AS1 group was significantly decreased (P<0.01); the proliferation, migration and invasion ability of cells were significantly decreased (all P<0.01). Luciferase reporter gene assay showed that CDKN2B-AS1 directly targeted miR-7-5p. The mRNAexpression of miR-7-5p, and protein expressions of cleaved caspase-3 and E-cadherininsh-CDKN2B-AS1groupandmiR-7-5pmimic group were significantly up-regulated (all P<0.05), whiletheproteinexpressionsofKi67,N-cadherin,andTwist1weresignificantlydown-regulated (all P<0.05). Conclusion: CDKN2B-AS1 targets miR-7-5p to promote the development of melanoma, and interfering with CDKN2B-AS1 can inhibit the malignant biological behaviors of melanoma B16-F10 cells.
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Objective To investigate the effect and underlying mechanism of lncRNA MEG3 on the radiosensitivity of nasopharyngeal carcinoma cells.Methods this experiment,overexpression control group,MEG3 overexpression group,miR-NC inhibition group,miR-7-5p inhibition group,overexpression control+4 Gy group,MEG3 overexpression+4 Gygroup,miR-NC inhibition+4 Gy group,miR-7-5p inhibition+4 Gy group,MEG3 overexpression + miR-NC overexpression group,MEG3 overexpression + miR-7-Sp overexpression group were established.The expression of miR-7-5p and MEG3 was detected by qRT-PCR.The radiosensitivity of nasopharyngeal carcinoma cells was measured by clone formation assay.Cell apoptosis was assessed by flow cytometry.The fluorescence activity was evaluated by dual luciferase reporter assay.Results MEG3 was lowly expressed in nasopharyngeal carcinoma tissues and cells.Overexpression of MEG3 and inhibition of miR-7-5p expression increased the radiosensitivity of nasopharyngeal carcinoma cells and promoted radiation-induced cell apoptosis.MEG3 could targetedly regulate the miR-7-5p expression.Overexpression of miR-7-5p reversed the effect of overexpression of MEG3 on the sensitization of nasopharyngeal carcinoma cells and the promotion of apoptosis induced by radiation exposure.Conclusions Overexpression of MEG3 increases the radiosensitivity of nasopharyngeal carcinoma cells and promotes radiation-induced cell apoptosis.The mechanism may be related to the down-regulation of miR-7-5p expression.
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OBJECTIVE: To investigate the mechanism of miR-7-5p in TK6 cell damage induced by hydroquinone( HQ) by constructing stable miR-7-5p over-expressing human lymphoblastoid TK6 cell line using lentivirus. METHODS: i) The miR-7-5p over-expression lentivirus vectors were constructed,and then infected to TK6 cells. The miR-7-5p overexpression stable TK6 cell line( TK6-miR-7-5p cells) and negative control cells( TK6-NC cells) were selected with puromycin. The infection efficiency was confirmed by real-time fluorescent quantitative polymerase chain reaction assay.ii) TK6,TK6-NC and TK6-miR-7-5p cells were treated with HQ at final concentrations of 0 and 40 μmol/L for 48 hours.Cell viability was determined by CCK-8 assay. The early apoptosis rate of cells was detected by flow cytometry. The relative expression of poly( ADP-ribose) polymerase-1( PARP-1) and breast cancer susceptibility gene 1( BRCA1) proteins in 3 kinds of cells treated with HQ at the final concentration of 40 μmol/L was detected by Western blotting. RESULTS: i) The TK6 cell line with stable expression of miR-7-5p were successfully screened. Compared with normal TK6 cells,the relative expression of miR-7-5p in TK6-miR-7-5p cells increased by about 17 times( P < 0. 01) with no significant changes in cell morphology. ii) After treatment with 40 μmol/L HQ,the survival rate of TK6-miR-7-5p cells decreased compared with normal TK6 cells and TK6-NC cells( P < 0. 01),early apoptosis rate increased( P < 0. 01),the relative expression of PARP-1 and BRCA1 protein was decreased( P < 0. 05). CONCLUSION: MiR-7-5p may lead to the increase of early apoptosis in TK6 cells induced by HQ through inhibiting the DNA damage repair capacity related to PARP-1 and BRCA1.
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Epstein-Barr virus (EBV)-encoded small non-coding RNAs (EBERs) are abundantly expressed in various EBV-associated malignancies, and play critical roles in cell proliferation, tumorigenesis, and apoptosis resistance. However, the mechanism how EBERs regulate cell function awaits further clarification. In this study, we investigated the effect of EBERs on the expression of cellular microRNA (miRNA) and mRNA expression. To test the effect of EBERs while unaffected by other EBV genes, we used EBERs-deleted recombinant EBV infected Burkitt's lymphoma cell line (Akata(+)EBERs(-)) as well as EBV-infected (Akata(+)) and EBV uninfected (Akata(-)) cell lines. They all have the same genetic backgrounds. First, 15 different cellular miRNAs which have reverse complementary sequences to EBERs and have reported targets were selected by bioinformatics analysis. When RT-PCR was carried out for the 16 miRNAs using RNAs from Akata(+), Akata(-), and Akata(+)EBERs(-) cells, hsa-miR-7-5p was the only one showing down-regulated expression in Akata(+) than in Akata(-) and Akata(+)EBERs(-) cells. Bioinformatics and mRNA microarray analyses for Akata(+), Akata(-), and Akata(+)EBERs(-) cell lines were then carried out to predict putative targets of hsa-miR-7-5p. Among the 6 predicted targets of hsa-miR-7-5p, only low density lipoprotein receptor-related protein 6 (LRP6) was up-regulated in EBERs-expressing cells when tested by RT-PCR and Western blot. However, luciferase reporter assay showed that the 3'-UTR of LRP6 was not directly targeted by hsa-miR-7-5p. Our data suggest that both hsa-miR-7-5p and LRP6 are regulated by EBERs in Akata cells, and these genes may partly mediate the tumorigenic function of EBERs in Burkitt's lymphoma.