BACKGROUNDIt was reported that telomerase expression is closely associated with cellular immortality and cancer. This study was designed to investigate the relationship between telomerase expression and the carcinogenesis of cervical cancer, the possible use of telomerase as a marker of cervical intraepithelial neoplasia (CIN) progression or regression, and the natural history of CIN.

METHODSTelomeric repeat amplification protocol (TRAP) assay was used to measure telomerase activity in cervical scrapings and biopsy samples obtained from 105 cases affected with various cervical conditions, including chronic cervicitis (n = 20), CIN (n = 64, 16 cases of CIN I, 20 cases of CIN II, and 28 cases of CIN III), and invasive squamous cell carcinoma (n = 21).

RESULTSIn exfoliated cell samples, telomerase activity was detected in 5 of 20 (25.0%) cases of cervicitis, 10 of 16 (62.5%) cases of CIN I, 11 of 20 (55.0%) cases of CIN II, 23 of 28 (82.1%) cases of CIN III, and 13 of 21 (61.9%) cases of carcinoma. In cervical biopsy samples, telomerase activity was detected in 6 of 20 (30.0%) cases of cervicitis, 8 of 16 (50.0%) cases of CIN I, 9 of 20 (45.0%) cases of CIN II, 27 of 28 (96.4%) cases of CIN III, and 20 of 21 (95.2%) cases of carcinoma. Telomerase activation was significantly higher in CIN samples than in cervicitis samples. Telomerase activity was detected at similar frequency in samples from cervical scrapings and cervical biopsies.

CONCLUSIONThese results seem to suggest that telomerase expression may be associated with carcinogenesis of the cervix. TRAP assay of cervical scraping samples could be used to monitor and predict the development of CIN in clinical practice.

Adult ; Biomarkers, Tumor ; analysis ; Cervical Intraepithelial Neoplasia ; enzymology ; Disease Progression ; Female ; Humans ; Middle Aged ; Telomerase ; metabolism ; Uterine Cervical Neoplasms ; enzymology ; Uterine Cervicitis ; enzymology

OBJECTIVETo define a correlation between different human papillomavirus (HPV) types and telomerase activity in cervical cancer.

METHODSTelomerase activity was detected by TRAP-PCR, and different HPV type was determined by PCR in 83 cervical cancer, 47 cervical intraepithelial neoplasia (CIN) and 10 normal cervix cases.

RESULTSWith regard to positive rates of telomerase and HPV 16/18: the results were cervical cancer > CIN > normal cervix, CIN III > CIN I, II; with regard to HPV 6/11 positive rate: the results showed CIN I, II > CIN III. Positive rates of telomerase cervical cancer and HPV were bearing on grading and staging, but they did not correlate with histologic subtypes. Positive rate of HPV 6/11 had nothing to do with grading, staging and histologic patterns. On expression strength of telomerase and HPV 16/18: the results showed cervical cancer > CIN, CIN III > CIN I, II. Regard to HPV 6/11'expression strength: the results showed CIN I, II > CIN III, CIN > cervical carcinoma.

CONCLUSIONHPV 16/18 infection seemed to have played an important role in carcinogenesis of cervical lesions by activation of telomerase.

Cervical Intraepithelial Neoplasia ; enzymology ; pathology ; virology ; Female ; Humans ; Neoplasm Staging ; Papillomaviridae ; isolation & purification ; Telomerase ; metabolism ; Uterine Cervical Neoplasms ; enzymology ; pathology ; virology

OBJECTIVETo study the thymidine phosphorylase (TP) expression in different types of cancer and its correlation with tumor microvessel density (MVD).

METHODSThe expression of TP and MVD was detected by immunohistochemistry method. In a series of 251 cancer patients there were 48 patients with gastric cancer, 53 with colorectal cancer, 47 with breast cancer, 56 with cervical cancer, 47 with lung cancer. Normal gastric (n = 25), colorectal (n = 25), cervical (n = 17) and lung (n = 25) tissues around the cancer were also examined.

RESULTSThe TP expression rate was 64.6% in gastric cancer, 67.9% in colorectal cancer, 80.9% in breast cancer, 82.1% in cervical cancer, and 63.8% in lung cancer, which was significantly higher than that in normal tissues (P = 0.0000). TP expression was positively correlated with MVD in gastric, colorectal, breast, and cervical cancers. The correlation was not statistically significant in lung cancer.

CONCLUSIONThis study indicates that TP overexpression in cancer may be associated with tumor angiogenesis.

Adult ; Aged ; Aged, 80 and over ; Breast Neoplasms ; blood supply ; enzymology ; Colorectal Neoplasms ; blood supply ; enzymology ; Female ; Humans ; Male ; Middle Aged ; Neovascularization, Pathologic ; pathology ; Stomach Neoplasms ; blood supply ; enzymology ; Thymidine Phosphorylase ; metabolism ; Uterine Cervical Neoplasms ; blood supply ; enzymology

To investigate the relationship between the expression of cyclooxygenase-2 (COX-2) and menstrual cycle, the regulatory effects of 17-beta-estradiol (E(2)) and medroxyprogesterone acetate (MPA) on the expression of COX-2 in cervical cancer Hela cells were examined. Cervical cancer specimens were obtained from 47 pre-menopausal patients. The phase of menstrual cycle was determined by case history and HE staining of uterine endometrium. COX-2 was immunohistochemically stained by SABC staining and the staining intensity was determined with computerized image analysis system. Hela cells were incubated with alcohol, E(2), E(2)+MPA, MPA for 12, 24 and 48 h respectively. The expression of COX-2 in Hela cells was detected by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Our results showed that the expression of COX-2 was significantly higher during proliferative phase than secretory phase (P<0.05), but there was no difference in the positive rate between proliferative phase and secretory phase (P>0.05). Incubation with E(2) could significantly enhance the expression of COX-2 continually. On the contrary, E(2)+MPA and MPA alone could decrease the expression of COX-2 as compared with the control and E(2) group (P<0.05 and P<0.01 respectively). It is concluded that the expression of COX-2 in cervical cancer of pre-menopausal patients and Hela cells was regulated by estrogen/progestogen.
Cyclooxygenase 2/genetics ; Cyclooxygenase 2/*metabolism ; Estradiol/*pharmacology ; Hela Cells ; Medroxyprogesterone Acetate/*pharmacology ; Uterine Cervical Neoplasms/*enzymology

We investigated the correlation between Cyclooxygenase-2 (COX-2) expression and the tumor response in patients with cervical cancer that were treated with curative radiotherapy (RT). Fifty-seven patients with squamous cell carcinoma were treated with concurrent radiochemotherapy (CRCT, n=29) or RT alone (n=28). The response of each patient was evaluated by three serial Magnetic Resonance Imaging examinations: before the start of RT, at four weeks after the start of RT (mid-RT) and at four weeks after the completion of RT (post-RT). Forty-three patients had positive COX-2 expression. The COX-2 negative patients achieved a higher rate of complete response (CR) at mid-RT than did the COX-2 positive patients (28.6% vs. 7.0%, P=0.054), but not at post-RT (64.3% vs. 69.8%). The initial tumor volume was a significant predictor of CR at mid-RT (P=0.003) and post-RT (P=0.004). The multivariate analysis showed that the initial tumor volume (at mid-RT and post-RT) and CRCT (at post-RT) were significant predictors of CR; however, the COX-2 expression was not. In conclusion, the COX-2 expression status has no significant correlation with the tumor response. Further studies on the changes in COX-2 expression levels during RT may be helpful for determination of its role in the tumor response to treatment and patient prognosis.
*Carcinoma, Squamous Cell/enzymology/pathology/radiotherapy ; Cyclooxygenase 2/*metabolism ; Female ; Humans ; Middle Aged ; Multivariate Analysis ; Neoplasm Staging ; *Uterine Cervical Neoplasms/enzymology/pathology/radiotherapy

OBJECTIVETo study the expressions and clinical significances of p-extracellular regulated kinase(P-ERK)1/2 and matrix metalloproteinase-9(MMP-9)in cervical squamous cell carcinoma.

METHODSThe expressions of P-ERK1/2 and MMP-9 in 30 cases with chronic cervicitis, 45 cases with cervical intraepithelial neoplasia (CIN), and 58 cases with cervical squamous cell carcinoma were detected by immunohistochemical method.

RESULTSThe positive rates of P-ERK1/2 and MMP-9 in chronic cervicitis, CIN, and cervical squamous cell carcinoma were 0 and 0, 28.9% and 24.4%, 77.6% and 65.5%, respectively, showing significant differences among these three groups (χ(2)= 54.393,p=0.003;χ(2)=40.968,p=0.005). The positive rates of P-ERK1/2 and MMP-9 in patients at clinical stages 2-3, at G3, with lymphatic metastasis, or with a tumor diameter greater than 4 cm were significantly higher than those at clinical stage 1(p=0.015,p=0.002), at G1-G2(p=0.013,p=0.017), without lymphatic metastasis (p=0.017,p=0.021), or with a tumor diameter less or equal than 4 cm in cervical squamous cell carcinoma(p=0.008,p=0.004). There was a positive correlation between P-ERK1/2 and MMP-9 in cervical squamous cell carcinoma (χ(2)=8.955,p=0.006).

CONCLUSIONSThe expressions of P-ERK1/2 and MMP-9 increase gradually with the progression of cervical squamous cell carcinoma. The over expressions of P-ERK1/2 and MMP-9 may promote the infiltration of cervical squamous cell carcinoma and lymphatic metastasis, druing which these two enzymes may exert their effects in a synergistic manner.

Carcinoma, Squamous Cell ; enzymology ; pathology ; Female ; Humans ; Matrix Metalloproteinase 9 ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Uterine Cervical Neoplasms ; enzymology ; pathology

BACKGROUNDHistone deacetylase (HDAC) inhibitors are a group of small chemical molecules that inhibit histone deacetylase. At cell level, HDAC inhibitors have multiple biological effects such as cell cycle arrest, apoptosis, cell differentiation and auotophagy. At molecular level, HDAC inhibitors cause histone and nonhistone acetylation and induce gene expression. HDAC inhibitors are widely used in cancer therapy because of its function of inducing apoptosis. However, the mechanisms of apoptosis effect are not fully understood. TSA is a classical HDAC inhibitor and widely used in epigenetic and anti-cancer research. In this study, we selected Trichostatin A (TSA) to investigate the mechanisms of HDAC inhibitors apoptotic effect on cancer cells.

METHODSCervical cancer cell lines such as Hela, Caski and normal human keratinocyte line HaCaT were treated with various concentrations of TSA. Crystal violent assay and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were performed to determine cell number. PARP cleavage and FITC-AnexinV were performed to determine apoptosis. DNA-methyltransferase (DNMT)1, DNMT3A and DNMT3B were determined by regular PCR, qPCR and Western Blotting. Small interfering RNA (SiRNAi) was used to knock down DNMT3B.

RESULTSHDAC inhibitors only induce cervical cancer cell apoptosis. At 1 µmol/L of TSA, 86% of Hela cell and 76% of Caski went apoptosis. For normal cells, HDAC inhibitors have no cytotoxic effect at therapeutic dosage, (90.0 ± 8.4)% of normal cell survive after treated with 1 µmol/L of TSA. We compared 1 µmol/L group with untreated control with t-test. There was no significance between 1 µmol/L group and untreated control for normal cell (P > 0.05). HDAC inhibitors decreased DNMT3B in cancer cell but not in normal cell. Manually knock-down of DNMT3B induced Hela and Caski cell apoptosis. More than 99% of Hela and Caski cell went apoptosis after deprived of DNMT3B.

CONCLUSIONSDNMT3B was essential to cervical cancer cell survival. Down-regulated DNMT3B by HDAC inhibitors may play an important role in the toxicity of HDAC inhibitors on cervical cancer cells.

Apoptosis ; drug effects ; genetics ; Cell Line ; Cell Line, Tumor ; DNA (Cytosine-5-)-Methyltransferases ; genetics ; metabolism ; Female ; HeLa Cells ; Histone Deacetylase Inhibitors ; pharmacology ; Humans ; Hydroxamic Acids ; pharmacology ; Uterine Cervical Neoplasms ; enzymology ; genetics

OBJECTIVETo investigate enhancement of the bystander effect by tanshinone IIA (Tan) in HSV-tK/GCV system and the correlation with expression of connexin 43 mRNA.

METHODSThe cytotoxic effect in HSV-tK/GCV in cervical carcinoma cell line ME180 (ME) and ME/TK was examined by MTT assays. Cx43 mRNA expression was detected by fluor-quantitative RT-PCR.

RESULTSTan markedly increased sensitivity of ME/TK cells for GCV in HSV-tK/GCV system. In the presence of 2 micro g/ml GCV, compared with the absence of Tan (0 mol/L), an obvious decrease in survival rate was seen at any given mixture of ME and ME/TK cells exposed to 1.3 x 10(-9) mol/L Tan. Statistics showed significant difference (P < 0.05). However, enhancement of bystander mediated cell killing occurred only in the range of Tan concentrations used (1.3 x 10(-8), 1.3 x 10(-9) mol/L). RT-PCR showed that the ratio of relative copy number of Cx43 mRNA increased by 8.83 and 8.47-fold in ME cells exposed to 1.3 x 10(-8) and 1.3 x 10(-9) mol/L Tan, respectively.

CONCLUSIONFor the first time we report that in cervical carcinoma ME180 cell line, Tan possesses a remarkable enhancing role on the bystander effect in the HSV-tK/GCV system. It is associated with up-regulation of Cx43 mRNA expression.

Antineoplastic Agents, Phytogenic ; pharmacology ; Bystander Effect ; Cell Line, Tumor ; Cell Survival ; drug effects ; Connexin 43 ; genetics ; Diterpenes, Abietane ; Female ; Ganciclovir ; pharmacology ; Genetic Therapy ; Humans ; Phenanthrenes ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Simplexvirus ; enzymology ; Thymidine Kinase ; genetics ; Uterine Cervical Neoplasms ; therapy

BACKGROUNDThe second mitochondria-derived activator of caspases (Smac) is a novel proapoptotic gene, which plays an important role in the apoptosis-inducing effects of irradiation on tumor cells. The purpose of this study was to investigate the effects of extrinsic Smac gene transfer and its over-expression in radiotherapeutic sensitivities of cervical cancer cells.

METHODSAfter the Smac gene was transferred into the cervical cancer cell line HeLa, subcloned cells were obtained by persistent G418 selection. Cellular Smac gene expression was detected by RT-PCR and Western blot, while in vitro cell viabilities were detected by trypan blue staining assay. After treatment with X-ray irradiation, cellular radiotherapeutic sensitivities were investigated by tetrazolium bromide colorimetry. Cellular apoptosis and its rate were determined by electronic microscopy, annexin V-FITC and propidium iodide staining flow cytometry. The expression and activities of cellular caspase-3 were assayed by Western blot and colorimetry.

RESULTSSmac mRNA and protein levels in HeLa/Smac cells and the selected subclone cell line of cervical cancer were significantly higher than those of HeLa (P < 0.01). There was no significant difference in cellular viabilities between them (P > 0.05). However, after irradiation with 8 Gy X-ray, growth activities of HeLa/Smac were reduced by 22.42% (P < 0.01). When compared with those of HeLa, partial HeLa/Smac cells presented characteristic morphological changes of apoptosis under electronic microscope, with higher apoptosis rates (16.4% vs. 6.2%, P < 0.01); the caspase-3 expression levels in HeLa/Smac cells were improved significantly (P < 0.01), while its activities were increased by 3.42 times (P < 0.01).

CONCLUSIONSStable transfer of the extrinsic Smac gene and its over-expression in cervical cancer cell line could significantly enhance the expression and activities of cellular caspase-3 and ameliorate apoptosis-inducing effects of irradiation on cancer cells, which was a novel strategy to improve radiotherapeutic effects on cervical cancer.

Apoptosis ; radiation effects ; Carrier Proteins ; genetics ; physiology ; Caspase 3 ; Caspases ; metabolism ; Female ; Gene Transfer, Horizontal ; HeLa Cells ; Humans ; Intracellular Signaling Peptides and Proteins ; Mitochondrial Proteins ; genetics ; physiology ; Radiation Tolerance ; Uterine Cervical Neoplasms ; drug therapy ; enzymology ; pathology