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Objective:To construct human immortalized keratinocytes stably expressing human papillomavirus type 16 (HPV16) E6/E7 gene, and provide a cell model for studying mechanisms underlying HPV16 E6/E7-induced cell immortalization and malignant transformation.Methods:Primary human foreskin keratinocytes (HFKs) were isolated by sequential two-step enzymatic digestion. Cultured HFKs were stably transfected with a HPV16 E6/E7 gene-overexpressing lentiviral vector LV5-HPV16 E6/E7, and consecutively cultured for more than 30 passages. Then, immortalized keratinocytes were screened out and divided into 3 groups: (1) blank control group: second-passage primary HFKs; (2) experimental group: HFKs transfected with LV5-HPV16 E6/E7 at different passages, and the second-passage primary HFKs transfected with LV5-HPV16 E6/E7 were referred to as A0 cells, thereafter, the transfected HFKs were named according to their passage number, such as A1, A2, ... A30; (3) positive control group: the HPV16-positive cervical cancer cell line SiHa. Real-time fluorescence-based quantitative PCR (qRT-PCR) and Western blot analysis were performed to determine the mRNA expression of HPV16 E6/E7 and protein expression of HPV16 E6/E7 and CK14, respectively, in the blank control group, experimental group and positive control group. Cell counting kit-8 (CCK8) assay and Transwell insert invasion assay were conducted to assess the cellular proliferative and invasive activity. In vivo tumor formation experiment in nude mice was conducted to investigate the tumorigenicity of A30 cells in the experimental group and SiHa cells in the positive control group. Results:Primary HFKs were successfully isolated. After the primary HFKs were transfected with the recombinant plasmid LV5-HPV16 E6/E7, the blank control group showed no fluorescence in the cells, but showed senescent phenotypes after serial passages, while in the experimental group, the volume and morphology of A30 cells were similar to those of the primary HFKs with the proportion of fluorescence-positive cells being 100%. Compared with the blank control group, the experimental group showed significantly increased mRNA expression levels of HPV16 E6 and E7 in A1, A10, A20 and A30 cells (HPV16 E6: t = 7.12, 8.07, 6.53, 5.66, P < 0.001, < 0.001, = 0.001, = 0.005, respectively; HPV16 E7: t = 3.20, 4.29, 3.75, 4.22; P = 0.024, 0.008, 0.013, 0.014, respectively) . The protein expression of HPV16 E6/E7 was absent in the blank control group, but was observed in A30 and SiHa cells. CCK8 assay showed that the proliferative activity of A10, A20 and A30 cells was significantly higher than that of the blank control group ( t = 6.49, 7.55, 9.43, P = 0.003, 0.002, 0.001, respectively) , while there was no significant difference in the proliferative activity between A1 cells and the blank control group ( t = 2.40, P = 0.074) . Transwell insert invasion assay showed that A30 cells could not cross the basement membrane, but SiHa cells could pass through the basement membrane and were stained blue. Two months after the inoculation with A30 cells in the nude mice, no visible tumors were found, which was confirmed by a histological study. Subcutaneous tumors were formed in the nude mice after the inoculation with SiHa cells. Conclusion:Human immortalized keratinocytes were successfully established by lentivirus-mediated transfection with HPV16 E6/E7 gene, and can serve as an ideal cell model for HPV-related research.
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Objective To explore the effect of tea polyphenols on the growth of human papillomavirus 16 (HPV16) subgenes-immortalized human cervical epithelial cells (H8 cells).Methods Cultured H8 cells were divided into 5 groups to be treated with 0 (control group),6.25,12.5,25 and 50 mg/L tea polyphenols respectively for 24,36,and 48 hours,and then cell counting kit-8 (CCK8)assay was performed to detect cell proliferation.After 24 hours of incubation,flow cytometry was conducted to detect cell apoptosis and cell cycle,and fluorescence microscopy to observe the morphology of apoptotic cells.Results After incubation with tea polyphenols at different concentrations for 24,36 and 48 hours,the proliferation of H8 cells was inhibited,and 12.5 mg/L tea polyphenols could inhibit the relative growth rate of H8 cells in a time-dependent manner.Flow cytometry showed that there was a significant difference in cell apoptosis rate among the 6.25-,12.5-,25-,50-mg/L tea polyphenols groups and the control group (52.62％ ± 0.62％,52.22％ ± 0.72％,42.52％ ± 0.90％,45.96％ ± 2.11％,29.96％ ± 0.70％ respectively,F =272.0,P ＜ 0.05).Moreover,all the tea polyphenol groups showed significantly increased cell apoptosis rate compared with the control group (all P ＜ 0.05).Fluorescence microscopy showed karyopyknosis,nuclear fragmentation and other typical apoptotic morphological changes in H8 cells in tea polyphenols groups.There were significant differences in the percentage of cells in G1,G2 phase and cell proliferation index among the 5 groups (all P ＜ 0.05).Compared with the control group,the 6.25-,12.5-,25-mg/L tea polyphenols groups showed significantly increased percentage of cells in G1 phase (55.96％ ± 0.72％,54.12％ ± 3.20％,65.30％ ± 1.51％ respectively,all P ＜ 0.05),but significantly decreased percentage of cells in G2 phase (3.17 ± 1.82％,4.94 ± 1.46％,4.65 ± 4.26％ respectively,all P ＜ 0.05) and lower cell proliferation index(0.44 ± 0.01,0.46 ± 0.02,0.36 ± 0.01 respectively,all P ＜ 0.05).Conclusion Tea polyphenols can inhibit the proliferation of H8 cells,induce cell apoptosis,and block cell cycle progression.
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ObjectiveTo explore the effect of JNK-c-Jun signal pathwayon connexin 43 (Cx43) expression and its role in renal tubular epithelial-myofibroblast transition (TEMT) induced by TGF-β1.Methods Normal rat kidney tubular epithelial cells(NRK-52E) were cultured in Dulbecco's modified eagle medium(DMEM) with 10％ fetal bovine serum,then were randomly divided into 3 groups: control group,TGF-β1 group (treated with TGF-β1 10 μg/L),and TGF-β1+SP600125 (selective JNK inhibitor,50 μmol/L) group. The protein expressions of JNK,c-Jun,α-SMA,Cx43 and E-cadherin were assayed by immunocytochemistry and Western blotting.The Cx43mRNA was assayed by RT-PCR.Gap junction intercellular communication(CJIC) was measured by fluorescence recovery after photobleaching assay(FRAP).Results TGF-β1increased the expressions of JNK,c-Jun and α-SMA(P＜0.05),reduced the expressions of Cx43 and E-cadherin (P＜0.05),and inhibited GJIC of NRK-52E(P ＜0.05).SP600125 could alleviate the above expressions changes and enhanced GJIC induced by TGF-β1.Conclusion JNK-c-Jun signal pathway induces TEMT ofNRK-52E treated with TGF-β1 viadown-regulation of connexin 43expression and inhibition of GJIC.
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Objective To examine the expression of response gene to complement 32 (RGC-32) in renal tissue of children with IgA nephropathy (IgAN), and to explore its significance. Methods The subjects were 45 children diagnosed as IgAN by renal biopsy. The expression of RGC-32, α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGF-β1) was examined by immunohistochemistry staining. The correlation of RGC-32 expression with α-SMA,TGF-β1, degree of renal pathological lesions and clinical index in IgAN was assessed by Spearman correlation analysis. Results RGC-32 protein located in renal tubular epithelial cells in normal and IgAN renal tissues. The positive expression index of RGC-32 in nomal group, IgAN mild group, moderate group and severe group was (18.29±6.22)%, (23.90±9.65)%, (31.23±9.86)%,and (34.52±10.63)% respectively. With more severity of renal pathological lesions, the expression of RGC-32 in IgAN was enhanced. The RGC-32 expression was positively correlated with the score of glomerulus and renal interstitium in children with IgAN (r=0.385, 0.347, P＜0.05), as well as α-SMA, TGF-β1 (r=0.594, 0.521, P＜0.01), but was not correlated with Scr, urinary NAG/Cr,Alb/Cr, IgG/Cr, and α1-M/Cr (r =0.117, -0.115, -0.138, -0.176, -0.028, all P ＞0.05).Conclusions RGC-32 protein locates in renal tubular epithelial cells in normal and IgAN renal tissues. RGC-32 may participate in the course of renal tubulointerstitial lesions in children with IgAN, especially in the course of epithelial-mesenchymal transition (EMT) induced by TGF-β1.
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Objective To investigate the influence of ?-interferon (?-IFN) on liver cancer cell line (Hep-G2). Methods Observing the expression of Fas and Bcl-2 by ?-IFN-pretreated Hep-G2 cells via immunohistochemical stain; subsequently treating these cells with adrimysin, and observing the cell death rate and apoptosis of these cell by MTT and electroscopy. Results (1) ?-IFN up-regulating the expression of Fas protein and down-regulating Bcl-2 protein (P
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Objective To construct the RNA interference (RNAi) eukaryotic expression vectors of galectin-1, and establish the LST-R1 cell lines stably transfected by RNAi vectors. Methods Two pairs of small interfering RNAs (siRNA) targeting to galectin-1 mRNA (GenBank: NM002305) were designed. The corresponding single-strand short hairpin interfering RNAs (shRNA), containing BamH Ⅰ, Hind Ⅲ sites and a 9nt hairpin structure, was synthesized and annealed. The annealed product and the linear eukaryotic expression plasmid pSuperior-puro, which were digested with Bgl Ⅱ and Hind Ⅲ, were ligated by T4 ligase to set up the interfering system. The recombined plasmid was identified with EcoR Ⅰand Hind Ⅲ enzyme digestion and sequencing, and co-transfected to LST-R1 cells with pcDNA6/TR with Lipofectamine2000. Positive clones were selected with 0.8?g/ml puromycin. After incubated with 4?g/ml tetracyclin for 48 hours, RT-PCR, Western blotting and immunochemistry were employed to determine galectin-1 mRNA and protein levels. Results Sequencing results suggested that the nucleotide sequence and read frame of RNAi eukaryotic exprssion vector of galectin-1, p-shRNA1 and p-shRNA2 were perfect. Stably transfected LST-R1 cell lines of p-shRNA1-LST and p-shRNA2-LST were established. The relative values of galectin-1 expression in LST-R1 cells, p-shRNA1-LST cells, p-shRNA2-LST cells and p-LST cells by RT-PCR were 0.616, 0.298, 0.373 and 0.641, respectively, and 1.00, 0.07, 0.38 and 0.97 by Western blotting. The p-shRNA1 gave the best interfering effect, which was in conformity with the results of immunochemistry measurement. Conclusions RNAi eukaryotic expression vector of galectin-1 mRNA has been successfully constructed. Establishment of the stably transfected LST-R1 cell lines may lay a foundation to explore the roles of galectin-1 in laterally spreading tumor.