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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 investigate the expression of DNA methyltransferase 2 (DNMT2) and 3a (DNMT3a) in the epidermis of patients with psoriasis vulgaris.Methods Between March 2009 and December 2010,46 patients with psoriasis vulgaris were enrolled from the Department of Dermatology,Hospital for Skin Diseases,Chinese Academy of Medical Sciences and Peking Union Medical College,and the Department of Dermatology of Yixing People's Hospital,and 28 healthy controls were enrolled from the Department of Dermatologic Surgery,Hospital for Skin Diseases,Chinese Academy of Medical Sciences and Peking Union Medical College.Real-time quantitative PCR was performed to determine the mRNA expression of DNMT2 and DNMT3a in the epidermis of the lesional and nonlesional skin of patients with psoriasis vulgaris,as well as in the epidermis of normal skin of the healthy controls.Results The mRNA expression of DNMT2 (expressed as 2-△△Ct) in the lesional skin,non-lesional skin of the patients and normal skin of the healthy controls was 0.62 ± 0.02,0.36-± 0.05 and 0.15 ± 0.11,respectively.The mRNA expression of DNMT2 was significantly higher in the lesional skin than in the non-lesional skin of the patients (t =6.23,P ＜ 0.01),and higher in the non-lesional skin of the patients than in the normal skin of the healthy controls (t =7.33,P ＜ 0.01).Additionally,the mRNA expression of DNMT3a was significantly higher in the lesional skin (0.85 ± 0.03) than in the non-lesional skin (0.43 ± 0.04) of the patients (t =5.66,P ＜ 0.01),and higher in the non-lesiona] skin of the patients than in the normal skin of healthy controls (0.18 ± 0.09,t =8.62,P ＜ 0.01).Conclusion Both DNMT2 and DNMT3a mRNA were abnormally expressed in the epidermis of patients with psoriasis vulgaris.
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Objective To evaluate the effects of lentivirus-delivered short hairpin RNA (shRNA) targeting human papillomavirus 16 (HPV16) E7 gene on the expression of 4 kinds of DNA methyltransferases (DNMTs),including DNMT1,DNMT3A,DNMT3B and DNMT3L,in HPV16-positive cervical cancer cell line SiHa.Methods The recombinant plasmid containing HPV16 E7 gene-targeting shRNA was constructed firstly.Then,the BLOCK-iTTM lentiviral RNAi expression system kit was used to package the lentiviral vector,which was transfected into 293T cells.The lentivirus-containing supernatants were collected at 48 and 72 hours after transfection.The SiHa cells were divided into 3 groups to be cultured with lentiviral supernatant containing HPV16 E7 gene-targeting shRNA recombinant plasmids mixed with complete medium at a ratio of 1:1 (shRNA group),lentiviral supernatant containing empty plasmids mixed with complete medium at a ratio of 1:1 (negative control group),and complete medium alone (blank control group),respectively.Real-time fluorescence-based quantitative PCR (qRT-PCR) was performed to measure mRNA expression of HPV16 E7 and 4 kinds of DNMTs in the above 3 groups at 0,48,96 hours after infection,and Western blot analysis to determine protein expression of the 4 DNMTs at 48,96 hours after infection.Results There were no significant differences in the mRNA expression of HPV16 E7 and the 4 DNMTs among the shRNA group,negative control group and blank control group at 0 hour after infection (all P ＞ 0.05).At 48,96 hours after infection,the mRNA expression of HPV16 E7 and the 4 DNMTs decreased significantly in the shRNA group compared with the negative control group and blank control group (all P ＜ 0.05),but did not differ between the negative control group and blank control group (all P ＞ 0.05).Additionally,E7,DNMT1,DNMT3A,DNMT3B and DNMT3L gene-silencing efficiencies in the shRNA group were 71.13％,50.53％,13.72％,46.27％ and 17.92％ at 48 hours,and 83.50％,74.2％,47.8％,64.7％ and 48.9％ at 96 hours after infection,respectively.Western blot analysis showed that the protein expression of the 4 DNMTs significantly decreased in the shRNA group compared with the negative control group and blank control group at 48,96 hours after infection (all P ＜ 0.01).Moreover,the protein expression of DNMT1,DNMT3A,DNMT3B and DNMT3L in the shRNA group gradually decreased over time,and was inhibited by 84％,37.2％,59.8％ and 49.3％ at 48 hours respectively,and by 73.1％,68.7％,55.5％ and 65.5％ at 96 hours after infection respectively.Conclusion Targeted silencing of E7 gene in HPV16-positive SiHa cells can interfere with the mRNA and protein expression of DNMT1,DNMT3A,DNMT3B and DNMT3L.
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Objective To evaluate effects of human papilloma virus(HPV)16E7 on expressions of six tumor suppressor genes(including MT1G, NMES1, RRAD, SFRP1, SPARC and TFPI2)in a cell line SiHa, as well as on its proliferation and apoptosis. Methods SiHa cells were divided into two groups to be transfected with a small interfering RNA targeting HPV16E7(E7SiRNA, experimental group)and an empty vehicle(negative control group) respectively, with SiHa cells receiving no treatment serving as the blank control group. After 48 hours, qPCR was performed to measure the mRNA expressions of E7 and six tumor suppressor genes, CCK?8 assay to evaluate cellular proliferative activity, and flow cytometry to assess apoptosis of SiHa cells. Results At 48 hours after the transfection, the experimental group showed significantly decreased E7 mRNA expression(0.25 ± 0.036, P0.05). Conclusion E7 may participate in HPV16?induced cellular malignant transformation by suppressing the mRNA expressions of 6 tumor suppressor genes, including MT1G, NMES1, RRAD, SFRP1, SPAR and TFPI2.
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Objective To investigate the role of tissue-resident memory T lymphocytes in the pathogenesis of psoriasis.Methods Clinical information was collected from 32 patients with progressive plaque psoriasis.Tissue specimens were obtained from both lesional and nonlesional psoriatic skin of all the patients,as well as from faded lesions in 9 of these patients.Tissue specimens from the normal skin of 10 healthy individuals served as the controls.Immunohistochemical staining was performed to detect the two characteristic surface markers CD69 and CDI03 on tissue-resident memory T lymphocytes and to analyze the status of these T lymphocytes at different stages of psoriasis.The results of immunohistochemical staining were compared by t test.Results The mean number of CD69+CD103+ T lymphocytes per high-power field was significantly higher in lesional skin than in nonlesional skin of the 32 patients (11.34 ± 7.60 vs.2.72 ± 4.20,t =8.46,P ＜ 0.01),but similar between psoriatic lesions in the 9 patients before and after subsidence (14.33 ± 2.21 vs.12.00 ± 4.58,t =1.98,P =0.08).There was no significant difference in the mean number of CD69+CD103+ T lymphocytes between nonlesional psoriatic skin and normal control skin (2.72 ± 4.20 vs.1.70 ± 2.98,t =0.71,P ＞ 0.05).Conclusion Tissue-resident memory T lymphocytes may play a role in the formation and recurrence of psoriatic lesions in patients.
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Objective To investigate the expression of CXCR7 in several cutaneous malignant tumors including cutaneous squamous cell carcinoma (SCC),basal cell carcinoma (BCC) and invasive cutaneous malignant melanoma and their cell lines,as well as its significance.Methods Tissue specimens were obtained from the lesions of 30 patients with cutaneous squamous cell carcinoma,25 patients with basal cell carcinoma and 30 patients with cutaneous malignant melanoma.Immunohistochemistry was performed to detect the expression of CXCR7 protein in these tissue specimens and several cell lines (A375 human melanoma cells,M14 human melanoma cells,A431 human epidermoid carcinoma cells,HaCaT human keratinocytes).The mRNA expression of CXCR7 in these cell lines was measured by reverse transcription PCR.Results CXCR7 protein was apparently expressed in invasive cutaneous malignant melanoma.The high expression rate of CXCR7 protein was significantly elevated in cutaneous malignant melanoma tissue specimens compared with SCC and BCC tissue specimens [80％ (24/30) vs.26.67％ (8/30) and 8％ (2/25),x2 =17.16,28.36,both P ＜ 0.05].CXCR7 mRNA was expressed in A375,M14 and A431 cells,but not in HaCaT cells,with the strongest expression observed in A375 cells.Immunohistochemistry revealed the expression of CXCR7 protein only in A375 cells.Conclusions CXCR7 is highly expressed in cutaneous malignant melanoma and A375 cells,which may be involved in the malignant invasion and metastasis of melanoma.
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ObjectiveTo investigate the correlation between the methylation status of HLA class Ⅰ genes(HLA-A, -B and -C) in psoriatic epidermis and disease severity in patients with psoriasis vulgaris. MethodsDNA specimens were obtained from the lesional and nonlesional epidermis of 46 patients with psoriasis vulgaris and from the normal skin of 28 human controls. Methylation specific PCR (MSP) was conducted to detect the methylation status of CpG islands in the promoter region of HLA-A, -B and -C genes. The severity of psoriasis was evaluated by psoriasis area and severity index(PASI) scores. ResultsThe percentage of promoter methylation of HLA-B and HLA-C genes was 4.35％(2/46) and 21.74％(10/46), respectively in nonlesional epidermis, 4.35％ (2/46) and 4.35％ (2/46), respectively in lesional epidermis from these patients. No methylation was observed for the promoter of HLA-A, -B or -C gene in the normal control epidermis or for that of HLA-A gene in the nonlesional or lesional epidermis from the patients. The frequency of HLA-C gene promoter methylation in the nonlesional epidermis was significantly higher than that in the lesional epidermis and control epidermis, but was uncorrelated to the disease severity. No significant difference was observed for the methylation frequency of HLA-A or -B gene promoter among the three groups of specimens. Conclusion Abnormal methylation of HLA-C gene promoter is observed in patients with psoriasis vulgaris.
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Objective To study LI gene sequence of HPV cp6108 from 5 cases of condyloma acuminata. Methods T-A cloning and direct sequencing of PCR product were used. Results The LI gene sequences of HPV cp6108 from 5 specimens were presented with the homology of 99% to reference sequence in GenBank. A total of 3 gene mutations were found, including a nonsense mutation of G70A, a missense mutation of D77N, and a missense mutation of Tl16P. Conclusions In comparison with the sequence in GenBank, at least 3 gene mutations of HPV CP6108, i.e. one nonsense mutation of G70A and missense mutations of D77N and Tl 16P, are found in the present study.
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Objective To develop a gene chip for the detection of common pathogens causing urogenital sexually transmitted infections. Methods The target pathogens were divided into three groups: viruses, bacteria, and lower eukaryotes. Three pairs of universal primers were designed and applied to amplify the target genes of these different pathogens in one PCR reaction system. The gene chips were then prepared via immobilization of the specific probes onto specially treated glass slides. Finally, the labeled amplicons were hybridized with the gene chips, scanned and analyzed using computer software. Results Amplicons were detected by agarose gel electrophoresis. The fluorescence signals for specific pathogens could be recognized in the gene chips, and were identical with the positions of the specific probes. Conclusions Gene chip is a specific, sensitive and rapid method for simultaneous detection of multiple sexually transmitted infections.
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Objective To systematically investigate the molecular epidemiological profiles of human papillomavirus (HPV) in patients with condyloma acuminata(CA). Methods Two hundred and one samples of HPV DNA isolated from CA were PCR amplified by the PGMY09/11 primer system. The PCR products were simultaneously hybridized to 37 specific HPV probes immobilized on a nylon strip and then genotyped. All DNA templates were further PCR amplified using HPV 6 and 11 type specific primers for verification. Results All samples were HPV DNA positive consisting of totally 31 genotypes, the types of which were type 11(53.7%, 108/201), 6(43.8%, 88/201), 16(6.5%, 13/201), 52(6.0%, 12/201), 33(5.5%, 11/201), cp6108 (5.5%, 11/201) and 42 (5.0%, 10/201). The samples infected with a single and mixed types of HPV accounted for 60.2% (121/201) and 39.8% (80/201) respectively. Consistent results were found with the detection of HPV6 and 11 between hybridization assay and type-specific PCR. Conclusions At least 31 HPV genotypes are associated with CA. HPV 11 predominates while 68, 40, 54, 67, 73, 82, 35, 64 and 83 are rare in CA. Type cp6108 is detected in CA for the first time with a high prevalence. HPV26, 69, 70, 71,72 and IS39 might be not associated with CA. CA infected with a single and mixed HPV types accounts for 60.2% and 39.8%, respectively.
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Objective To clone and express immunodominant fragment of glycoprotein G of HSV-2 (FgG-2). Methods The target gene was amplified by polymerase chain reaction (PCR). The PCR products were ligated into directional TOPO expression vector. After identification, the recombinant expression vector was transferred into BL21 StarTM cell for expression. Finally, recombinant protein of FgG-2 (rFgG-2) was detected by Western Blot (WB). Results A 616 bp DNA fragment was obtained with PCR and then confirmed in recombinant vector by PCR and sequencing, bearing 99.5% consistent sequence with target gene. Highest recombinant protein production was obtained at the time point of 3 hours. Expression of target protein was confirmed by WB with anti-gG monoclonal antibody. Conclusions The immunodominant fragment of gG-2 has been successfully cloned and expressed in E.coli, which might be used for the development of serum diagnostics assay kits for HSV-2 infection.