OBJECTIVETo study the effect of As2O3 induction of HeLa cell apoptosis on HPV18 E6 expression and telomerase activity.

METHODSHeLa cells were treated with As2O3 in various concentrations. The effect of As2O3 on HeLa cell survival and apoptosis was determined by MTT assay, light and electron microscopy, and flow cytometry. Telomerase activity in HeLa cells was determined by TRAP-ELISA and the expression of HPV18 E6 mRNA was assayed by RT-PCR.

RESULTSAfter being treated with 2 micromol/L As2O3 for 48 h, the survival of HeLa cells decreased, and marked apoptosis was observed in a time- and dose-dependent manner. There was a good correlation between cell apoptosis and viral E6 gene expression and inhibition of telomerase activity following As2O3 treatment.

CONCLUSIONThe molecular mechanisms of As2O3 effect on HeLa cells may be related to down-regulation of HPV18 E6 oncogene expression and inhibition of telomerase activity.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; DNA-Binding Proteins ; biosynthesis ; genetics ; Down-Regulation ; HeLa Cells ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Oxides ; pharmacology ; Telomerase ; metabolism

OBJECTIVE: To investigate the mechanism of migration phenotype change induced by EBV-LMP1 in nasopharyngeal carcinoma (NPC) cell line CNE2. METHODS: Retroviruses RV-LNSX, RV-LMP1, and RV-LMP1(TRADD) prepared previously were used to infect CNE2 cells. After selection with G418, the morphology, the ability of motion and migration in extracellular matrix, expression of LMP1 and E-Cadherin in transgenic cells were observed or detected. Meanwhile, pEcad-luc was respectively co-transfected with pLNSX, pLNSX-LMP1, and pLNSX-LMP1(TRADD), to examine the effect of LMP1 on the transcriptional activity of E-Cadherin promoter in 293 cells. RESULTS: Compared with CNE2 and CNE2-LNSX cells, CNE2-LMP1 cells morphologically changed from typical epithelial appearance to long-spindle fibroblastic morphology with the concomitant loss of cell-to-cell contact, and relative migration of CNE2-LMP1 cells obviously increased (n=3, P< 0.05), while the expression of E-Cadherin was negative in CNE2-LMP1 cells. The transcriptional activity of E-Cadherin promoter and the expression of E-Cadherin was suppressed by LMP1, and the level of suppression was correlated with the concentration of pLNSX-LMP1 (0.2,0.6 and 1.0 microg). LMP1(TRADD) didn't induce the changes of morphology and migration phenotype, nor suppress the transcriptional activity of E-Cadherin promoter and the expression of E-Cadherin in CNE2 cells. CONCLUSION EBV-LMP1 promotes the migration and down-regulates the expression of E-Cadherin in CNE2 cells. The mechanism is that EBV-LMP1 suppresses the transcriptional activity of E-Cadherin promoter. TRADD of carboxyl terminus of LMP1 may be the main active domain to promote the migration in NPC cells.
Cadherins ; biosynthesis ; genetics ; Cell Line, Tumor ; Cell Movement ; drug effects ; Humans ; Nasopharyngeal Neoplasms ; pathology ; Oncogene Proteins, Viral ; genetics ; isolation & purification ; pharmacology ; Transfection ; Viral Matrix Proteins ; genetics ; isolation & purification ; pharmacology

OBJECTIVE: To investigate the effect of human papillomavirus types 16E6 on the sensitivity of chemotherapy for cervical carcinoma in different p53 genotype cell lines. METHODS: The apoptosis rates of each group were detected by AO/EB, immunofluorescence and Annexin V/PI stained methods. The expressions of protein HPV16E6 and p53(mt) after the treatments of different concentration of DDP were detected by Western blot. HPV16E6 mRNA in C33A, C33A-E6, C33A-P, and CaSki cell lines under different DDP treatments were detected by RT-PCR. RESULTS: AO/EB and Annexin V/PI stained tests showed that the apoptosis rates of C33A, C33A-E6, C33A-P, and CaSki cells were significantly increased when DDP concentration increased. Western blot showed that the HPV16E6 protein could be detected only in C33A-E6 and CaSki cell lines. The expression of HPV16E6 protein in C33A-E6 and CaSki cell lines gradually decreased and was hardly detected with increased dosage of DDP and the prolonged treatment time (P<0.01), and slightly increased in C33A-E6 and Caski cell lines without the treatment, but there was no significant difference between them (P>0.05). Protein p53(mt) persistently expressed in C33A-E6, C33A, and C33A-P cell lines following the increased dosage of DDP and the prolonged treatment time(P>0.05), while it couldn't be found in CaSki cell line. RT-PCR showed that without DDP intervention, there was no significant difference of HPV16E6 mRNA in C33A-E6 and CaSki cell lines within 24 h.The HPV16E6 mRNA in C33A-E6 cell line expressed much higher than that in CaSki (P<0.05), and HPV16E6 mRNA of 2 cell lines expressed much higher at 48 h than at 24 h (P<0.05).The expression of HPV16E6 mRNA in C33A-E6 and CaSki cell lines gradually decreased with the increased DDP and prolonged treatment time (P<0.01), while there was no significant difference between C33A-E6 and CaSki cell lines under the same DDP concentration (P>0.05). CONCLUSION Effect of HPV16E6 on the sensitivity of chemotherapy for cervical carcinoma cell lines is not markedly related with the different p53 genotype forms(p53(mt)/p53wt ). HPV16E6 may affect the proliferation and sensitivity of chemotherapy in C33A cell line through other mechanism.
Antineoplastic Agents ; pharmacology ; Apoptosis ; genetics ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Female ; Genotype ; Human papillomavirus 16 ; genetics ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Papillomavirus Infections ; virology ; Repressor Proteins ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Uterine Cervical Neoplasms ; pathology ; virology

Hydrogen peroxide is considered to be a dose- and time-dependent mediator in apoptotic and necrotic death. In this study, we examined the signaling of the E6 and E7 proteins with respect to apoptosis or necrosis after H2O2 injury using an in vitro model with overexpressed E6 or E7 genes. For this purpose, the E6 and E7 gene expressing astrocytes were exposed to 0.01 mM and 0.2 mM H2 O2 solutions. Twenty- four hours after treatment with the lower dosage(0.01 mM H2O2), control, E6-expressing cells suffered about 45% injury and LXSN-expressi ng cells decreased by 67% as assessed by LDH release. However, E7-expressing cells showed less injury, resulting in 20-30% of LDH release. Astrocytes expressing E6, E7, LXSN and mock-infected cells showed a typical apoptotic death patter n on the DNA gel after treatment with a low-dose of H2O2 (0.01 mM), however the y died from necrotic death after a high-dose (0.2 mM) H2O2. Overexpression of HPV-E7 genes protected the cells from apoptotic death after a low-dose of H2O2 and from necrotic death after a high-dose of H2O2, while the overexpression of E 6 genes from the necrotic death. E7 expressing astrocytes showed higher catalas e activity and the levels of E2F protein surged more than 100-folds compared with the control astrocytes. We believe that the activity of E7 protein to protect astrocytes from H2O2 injury was at least partly due to increased catalase, a scavenger protein.
Animal ; Apoptosis/*physiology ; Astrocytes/*drug effects/pathology/*physiology ; Cells, Cultured ; Hydrogen Peroxide/*pharmacology ; Mice ; Necrosis ; Oncogene Proteins, Viral/*genetics/*physiology ; Oxidants/*pharmacology ; Signal Transduction/physiology

OBJECTIVETo study the growth-inhibitory and apoptosis-inducing effects of realgar nanometer suspension in human carcinoma cervical cell Siha line, and the effect on HPV16E6/E7 oncogene expression.

METHODA " micro-jet efflux" strategy was used for the preparation of realgar nanometer suspension. Siha cells were treated with various concentrations (6.25, 12.5, 25, 50 mg x L(-1)) of realgar nanometer suspension for different hours (12, 24, 48, 72 h). The effect of realgar nanometer suspension on Siha cell growth suppression was detected by MTT method. Special morphological changes of apoptosis were observed by light and transmission electron microscopy (TEM) and DNA fragments electrophoresis. The apoptotic rates were quantified by flow cytometry (FCM). The expression of HPV16E6/E7 mRNA was assayed by RT-PCR.

RESULTAfter being treated with 25-50 mg x L(-1) realgar nanometer suspension for 48, 72 h, the survival of Siha cells decreased, and the rate of apoptosis markedly increased. With TEM and DNA electrophoresis, the special morphological changes were found. The apoptotic rates of Siha cells treated with realgar nanometer suspension were significantly higher than those in the control group (P < 0.01). G0-G1 phase arrest appeared following the treatment with realgar nanometer suspension in 25 and 50 mg x L(-1) 48 h. RT-PCR assay revealed that realgar nanometer suspension reduced HPV16E6/E7 gene expression.

CONCLUSIONRealgar nanometer suspension can inhibit the proliferation of human carcinoma cervical cell Siha line and induce the cell apoptosis. The mechanism may be related to the down-regulation of HPV16E6/E7 oncogene expression.

Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Line, Tumor ; Flow Cytometry ; Gene Expression ; drug effects ; Humans ; Microscopy, Electron, Transmission ; Oncogene Proteins, Viral ; genetics ; Papillomavirus E7 Proteins ; Repressor Proteins ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sulfides ; pharmacology

OBJECTIVETo elucidate the expression of tanscription factor Ets-1 mediated by EB virus encoded latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma (NPC) cells.

METHODSLMP1-expressing NPC HNE2 cells regulated by Tet-on system (pTet-on-LMP1 HNE2) were used. Expression of LMP1 and Ets-1 was observed after induction with Doxycycline (Dox). Expression of Ets-1 mRNA and protein was detected by RT-PCR and Western blot, respectively. The phosphorylation level of Ets-1 protein was examined by co-immunoprecipitation. The DNA binding activity of Ets-1 was detected by electrophoretic-mobility shift assay (EMSA).

RESULTSAfter induction with Dox in pTet-on-LMP1 HNE2 cells, to some extent, the expression of Ets-1 mRNA and protein, its phosphorylation level and DNA binding activity were increased with enhancement of LMP1 expression.

CONCLUSIONLMP1 induces transcriptional activation and expression of Ets-1 which may contribute to the development of NPC.

Carcinoma, Squamous Cell ; metabolism ; pathology ; virology ; Cell Line, Tumor ; Doxycycline ; pharmacology ; Herpesvirus 4, Human ; Humans ; Nasopharyngeal Neoplasms ; metabolism ; pathology ; virology ; Phosphorylation ; Proto-Oncogene Protein c-ets-1 ; Proto-Oncogene Proteins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-ets ; RNA, Messenger ; biosynthesis ; genetics ; Transcription Factors ; biosynthesis ; genetics ; Viral Matrix Proteins ; biosynthesis ; genetics ; physiology

PURPOSE: To establish the immortalized human corneal endothelial cell line (IHCEn) by transducing human papilloma virus (HPV) 16 E6/E7 oncogenes, and to identify their characteristics when cultivated on a lyophilized human amniotic membrane (LAM). METHODS: Primary human corneal endothelial cells (PHCEn) were infected using a retroviral vector with HPV 16 E6/E7, and transformed cells were clonally selected by G418. Growth properties and characteristics of IHCEn were compared with PHCEn by cell counting and RT-PCR of VDAC3, SLC4A4, CLCN3, FGF-1, Col IV, and Na+/K+ ATPase. IHCEn were cultured on LAM. Messenger RNA expressions of VDAC3, CLCN3, and Na+/K+ ATPase, and protein expressions of Na+/K+ ATPase and Col IV in IHCEn cultivated on LAM were investigated by RT-PCR, immunofluorescence, and immunohistochemical staining, respectively. RESULTS: Successful immortalization was confirmed by stable expression of HPV 16 E6/E7 mRNA by RT-PCR, and IHCEn exhibited typical corneal endothelial morphology. Doubling time of IHCEn was 30.15+/-10.96 hrs. Both IHCEn and PHCEn expressed VDAC3, CLCN3, SLC4A4, FGF-1, Col IV, and Na+/K+ ATPase. IHCEn cultivated on LAM showed stronger expression of VDAC3, CLCN4, and Na+/K+ ATPase mRNA than on plastic culture dish. Immunohistochemical staining and immunofluorescence revealed the positive expression of Na+/K+ ATPase and Col IV. CONCLUSIONS: IHCEn were successfully established, and LAM is a good substrate for the culture of human corneal endothelial cells.
Transfection ; Reverse Transcriptase Polymerase Chain Reaction ; Repressor Proteins/genetics/*pharmacology ; RNA, Messenger/genetics ; Protein-Tyrosine Kinases ; Oncogene Proteins, Viral/genetics/*pharmacology ; Immunohistochemistry ; Humans ; Gene Expression Regulation, Viral ; Freeze Drying ; Endothelium, Corneal/*cytology/drug effects/metabolism ; Cell Line, Transformed ; Cell Count ; Amnion

BACKGROUNDTo study the effect of human papillomavirus (HPV) 16 E6/E7 and TPA (12-O-tetradecanog-1-phorbol-13-acetate) on malignant transformation of human embryo oral tissue.

METHODSRecombinant plasmid with HPV 16 E6/E7 was constructed and transfected into human embryo oral tissue. The oral tissue with HPV 16 E6/E7 gene or without the gene was inoculated into the hypophloeodal of right shoulder in scid mice, respectively. The study was conducted in four groups: the first group was the oral tissue transfected plasmid with HPV 16 E6/E7 plus TPA, which were inoculated into 8 scid mice; the second group was only oral tissue transfected with plasmid with HPV 16 E6/E7 into 6 scid mice; the third group was normal oral tissue plus TPA inoculated into 6 scid mice, and the final group was only normal oral tissue inoculated into 5 scid mice. Three days after inoculation, TPA was injected at the left shoulder of the mice once a week. Twelve weeks after inoculation, tumor was found in 7 scid mice from the first group. HPV 16 E6/E7 gene in tumor tissues was analyzed by PCR.

RESULTSThe rate of tumor formation was 7/8 in the first group; no tumor was found in the other groups. Pathological diagnosis of the tumor was fibrohistiocytoma. HPV 16 E6/E7 gene was detected by PCR in tumor tissues.

CONCLUSIONWith the cooperating action of TPA, human oral tissue containing HPV 16 E6/E7 gene could cause malignant transformation in scid mice.

Animals ; Carcinogens ; pharmacology ; Carcinoma ; pathology ; virology ; Cell Transformation, Neoplastic ; drug effects ; Cells, Cultured ; Human papillomavirus 16 ; genetics ; metabolism ; Humans ; Mice ; Mice, SCID ; Mouth Neoplasms ; pathology ; virology ; Oncogene Proteins, Viral ; genetics ; metabolism ; Papillomavirus E7 Proteins ; genetics ; metabolism ; Papillomavirus Infections ; pathology ; virology ; Repressor Proteins ; genetics ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacology

OBJECTIVETo investigate the high expression of HPV16L2N120E7E6 fusion protein by prokaryotic expression system, and evaluate its immunogenicity and antitumor efficacy in vaccinated mice.

METHODSThe HPV16L2N120E7E6 fusion gene, its codons were optimized to increase the expression of the protein, was constructed by overlap extension PCR and inserted into prokaryotic expression vector pET9a. Then the fusion protein was expressed by inducing with IPTG in E. coli strain BL21 (DE3) harboring with plasmid pETL2N120E7E6, and further detected by SDS-PAGE and Western-blot. Finally, the humoral and cellular immune responses were measured by ELISA and ELISPOT, respectively, in vaccinated mice with the purified HPV16L2N120E7E6 fusion protein, and the antitumor efficacy was assessed in mice using the TC-1 tumor challenge model.

RESULTSThe codon-optimized HPV16L2N120E7E6 fusion gene was highly expressed in E. coli strain BL21 (DE3) harboring with plasmid pETL2N120E7E6, and the amount of fusion protein was nearly 48.6% of the total bacterial protein. The purified fusion protein could induce high titer of specific antibody against L2, E7 and E6 in vaccinated mice. When accompanied with the adjuvant CpG, the fusion protein was able to elicit strong and moderate cellular immune responses in vaccinated mice against peptide HPV16E7(49-57) and peptide pools of HPV16E6, respectively. Furthermore, the tumor therapeutic experiment showed that HPV16L2N120E7E6 + CpG could prevent the tumor formation in 80.0% (8/10) vaccinated mice.

CONCLUSIONSThe data of this study suggest that HPV16L2N120E7E6 fusion protein could be a promising candidate vaccine for treatment of chronic HPV16 infection and post-operative adjuvant therapy for cervical cancer.

Adjuvants, Immunologic ; pharmacology ; Animals ; Cancer Vaccines ; immunology ; therapeutic use ; Capsid Proteins ; genetics ; immunology ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Codon ; Escherichia coli ; immunology ; metabolism ; Female ; Humans ; Immunization ; methods ; Immunotherapy ; methods ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Oligodeoxyribonucleotides ; immunology ; Oncogene Proteins, Viral ; genetics ; immunology ; metabolism ; Papillomavirus E7 Proteins ; genetics ; immunology ; metabolism ; Papillomavirus Vaccines ; immunology ; therapeutic use ; Plasmids ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism ; Repressor Proteins ; genetics ; immunology ; metabolism

OBJECTIVETo investigate the inhibitory effect of compound cantharides capsules on the proliferation of xenografts of human hepatocellular carcinoma HepG(2215) in mice and their mechanism of action.

METHODSOne hundred healthy Balb/c mice (5-week old, male:female 1:1) were used in this study. Mouse models of human HepG(2215) hepatocarcinoma were established. The tumor-bearing mice were divided into five groups randomly. The control group A received daily intragastric administration of physiologic saline. The intervention groups B1, B2 and B3 were treated with compound cantharides capsule in a dose of 12.5 mg×kg(-1)×d(-1), 25 mg×kg(-1)×d(-1) and 37.5 mg×kg(-1)×d(-1), respectively, for 10 consecutive days. The group C had intraperitoneal injection of cyclophosphamide (25 mg×kg(-1)×d(-1)) for 10 consecutive days. The mice were sacrificed after the completion of administration. The tumors were taken out, the tumor volume was measured, the inhibitory rate of body weight was calculated, and the serum AFP concentration and the level of HBV DNA were determined. The survival of each group mice was analyzed. The levels of mRNA expression of apoptosis-related genes were assayed by quantitative RT-PCR. Apoptosis in the tumor cells was assayed with TUNEL staining. Flow cytometry was used to detect the levels of CD3(+), CD19(+), CD4(+) and CD8(+), and microvessel density (MVD) of the tumors was assessed by immunohistochemistry.

RESULTSAfter completion of the treatment, the inhibition rate of tumor growth of the groups B1, B2 and B3 was 29.8%, 38.7% and 48.1%, respectively, and that of the group C was 52.4%, with a significant difference among the groups (P < 0.05). The median survival time of the groups A, B1, B2, B3 and C was (30.0 ± 3.2) days, (49.0 ± 5.1) days, (50.0 ± 5.2) days, (57.5 ± 6.5) days and (49.0 ± 4.7) days, respectively. The median survival time of the group B3 was significantly longer than that of other groups (P < 0.05). The serum AFP level in the groups A, B1, B2, B3 and C was (492.7 ± 48.5) ng/ml, (281.2 ± 25.6) ng/ml, (194.3 ± 18.7) ng/ml, (170.1 ± 15.8) ng/ml and (138.7 ± 12.5) ng/ml, respectively, indicating that it was significantly inhibited in the group C. The inhibition rate of HBV DNA replication of the groups B1, B2, B3 and C was (46.0 ± 5.1)%, (65.5 ± 6.9)%, (81.3 ± 7.8)% and (19.5 ± 2.1)%, respectively, showing that compound cantharides capsules inhibited HBV DNA replication in a dose-dependent manner. The apoptosis rate of the groups A, B1, B2, B3 and C was (0.27 ± 0.03)%, (7.18 ± 2.12)%, (9.17 ± 2.42)%, (11.27 ± 3.03)% and (5.44 ± 2.45)%, respectively, and that of the group B3 was significantly higher than that of the groups A, B1, B2 and C (P < 0.05). The expression level of bax mRNA was significantly higher than that of the group C (P < 0.05). The drug could significantly decrease the bcl-2 mRNA expression level, more remarkably along with the increasing dose of cantharides, and it was significantly lower than that in the group C (P < 0.05). The levels of CD4(+), CD8(+), CD3(+) and CD19(+) were significantly higher than that in the groups A and C (P < 0.05). The value of MVD of the group B3 was significantly lower that that of groups A and C (P < 0.05).

CONCLUSIONCompound cantharides capsules may inhibit the replication of HBV DNA in HepG(2215) cells, inducing apoptosis in the tumor cells, enhancing the immune function to inhibit the growth of liver cancer cells in mice, and significantly prolong the median survival time of tumor-bearing mice.

Animals ; Antineoplastic Agents ; administration & dosage ; pharmacology ; Antiviral Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cantharidin ; administration & dosage ; pharmacology ; Capsules ; DNA Replication ; DNA, Viral ; Drug Combinations ; Female ; Hep G2 Cells ; Hepatitis B virus ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Microvessels ; pathology ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Tumor Burden ; drug effects ; Virus Replication ; Xenograft Model Antitumor Assays ; alpha-Fetoproteins ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism