The role of the globular heads of the C1q receptor in HPV-16 E2-induced human cervical squamous carcinoma cell apoptosis via a mitochondria-dependent pathway.

BACKGROUND: Human papillomavirus type-16 (HPV-16) E2 protein acts as a transcriptional modulator and plays a key role in regulating many biological responses. The purpose of this study was to investigate the relationship between HPV-16 E2, the receptor for the globular heads of human C1q (gC1qR) gene expression, mitochondrial dysfunction and apoptosis regulation in human cervical squamous carcinoma cells (C33a and SiHa). METHODS: HPV-16 E2 and gC1qR expression was examined using real-time PCR and western blot analysis. Apoptosis in C33a and SiHa cells was assessed by flow cytometry. Mitochondrial function was detected via ROS generation, the amount of cytosolic Ca2+, and changes in the mitochondrial membrane potential (Δψm). RESULTS: The expression of the HPV-16 E2 and gC1qR gene significantly decreased in human cervical squamous carcinoma samples relative to the non-cancerous cervix samples. C33a and SiHa cells that were transfected with a vector encoding HPV-16 E2 displayed significantly increased gC1qR gene expression and mitochondrial dysfunction as well as an up-regulation of cellular apoptosis, which was abrogated by the addition of gC1qR small-interfering RNA (siRNA). CONCLUSIONS: These data support a mechanism whereby gC1qR plays an important role in HPV-16 E2-induced human cervical squamous carcinoma cell apoptosis via a mitochondria-dependent pathway.

The role of the globular heads of C1q receptor (gC1qR) gene in regulating apoptosis of human cervical squamous cell carcinoma.

BACKGROUND: The globular heads of the human C1q receptor (gC1qR) are multi-compartmental and multi-functional cellular proteins. The list of biological responses mediated by the gC1qR includes growth perturbation and morphological abnormalities, along with the initiation of apoptosis. However, the effects of the gC1qR on the apoptosis of cervical squamous carcinoma cells (C33a and SiHa) have not been demonstrated. METHODS: Here, human cervical tissues were examined for the expression of the gC1qR using real-time PCR and Western blot analysis. Apoptotic death of C33a and SiHa cells was assessed by flow cytometric analysis to detect the subG1 population. Viability, migration and proliferation of C33a and SiHa cells were detected via the water-soluble tetrazolium salt (WST-1) assay, the Transwell assay and the (3)H-thymidine incorporation into DNA assay ((3)H-TdR), respectively. RESULTS: These data showed that expression of the gC1qR protein was significantly decreased in human cervical squamous cell carcinoma tissues relative to normal cervix tissues. C33a and SiHa cells transfected with a GFP-gC1qR vector resulted in the up-regulation of cellular apoptosis and an apparent increase in the expression of the p38 mitogen-activated protein kinase (p38 MAPK). Further, the changes in C33a and SiHa cells viability, migration and proliferation observed upon overexpression of gC1qR could be abrogated using the p38 MAPK inhibitor SB202190. CONCLUSION: These data indicate that gC1qR inhibits viability, migration and proliferation of cervical squamous cells carcinoma via the p38 MAPK signalling pathway.

The globular heads of the C1q receptor regulate apoptosis in human cervical squamous carcinoma cells via a p53-dependent pathway.

BACKGROUND: The globular heads of the human C1q receptor (gC1qR) localize predominantly to the mitochondrial matrix. gC1qR mediates many biological responses, including growth perturbation, morphological abnormalities and the initiation of apoptosis. The purpose of this study was to investigate the relationship between mitochondrial dysfunction, p53 status and gC1qR expression and the regulation of apoptosis in human cervical squamous carcinoma cells (C33a and SiHa). METHODS: Here, gC1qR expression was examined in human cervical tissues using real-time PCR and Western blot analysis. Apoptotic death of C33a and SiHa cells was assessed by flow cytometric analysis that detected the subG1 population. Mitochondrial function was assessed via ROS generation, the content of cytosolic Ca2+, and the change in mitochondrial membrane potential (Δψm). The viability and migration of C33a and SiHa cells were detected via the water-soluble tetrazolium salt (WST-1) assay and the transwell assay, respectively. RESULTS: gC1qR expression was decreased in cervical squamous cell carcinoma tissues compared with normal tissues. C33a and SiHa cells transfected with a vector encoding gC1qR displayed mitochondrial dysfunction and apoptosis, which was abrogated by the addition of a mutant form of p53 or p53 small interference RNA (siRNA). Furthermore, upon overexpression of gC1qR, cell viability and migration were significantly enhanced, and the apoptosis of C33a and SiHa cells were decreased when cells were treated with mutant p53 or p53 siRNA. CONCLUSIONS: These data support a mechanism whereby gC1qR induces apoptosis through the mitochondrial and p53-dependent pathways in cervical squamous cell carcinoma.

Human telomerase RNA gene amplification detection increases the specificity of cervical intraepithelial neoplasia screening.

OBJECTIVES: The purpose of this study was to evaluate the clinical significance of genomic amplification of the human telomerase RNA gene (TERC) for cervical cancer screening and explore whether it can serve as a biomarker to improve the specificity of human papillomavirus (HPV) DNA testing for cervical cancer screening. METHODS: One hundred twenty women, including 20 cases of normal (control), 14 cases of cervical intraepithelial neoplasia grade I (CIN I), 35 cases of CIN II, 36 cases of CIN III, and 15 cases of squamous cervical cancer diagnosed by histopathologic evaluation, were subjected to cytopathologic examination, TERC detection by fluorescence in situ hybridization (FISH), and HPV DNA testing by Hybrid Capture II. RESULTS: TERC amplification was significantly associated with cytopathologic diagnosis (P < 0.001) and histopathologic evaluation (P < 0.001). The positive rate of TERC gain was significantly higher in patients with CIN III or squamous cervical cancer than in patients with CIN I or those in the control group (P < 0.001). The specificity and positive predictive value of FISH for detecting CIN II or more severe cervical lesions (> or = CIN II) were obviously higher than those of HPV DNA testing (97.1% vs 52.9%, 98.7% vs 83.8%). CONCLUSIONS: TERC amplification analyzed by FISH may serve as an adjunctive test to HPV DNA testing for improving the specificity and positive predictive value of cervical cancer screening.

Cooperation of decay-accelerating factor and membrane cofactor protein in regulating survival of human cervical cancer cells.

BACKGROUND: Decay-accelerating factor (DAF) and membrane cofactor protein (MCP) are the key molecules involved in cell protection against autologus complement, which restricts the action of complement at critical stages of the cascade reaction. The cooperative effect of DAF and MCP on the survival of human cervical cancer cell (ME180) has not been demonstrated. METHODS: In this study we applied, for the first time, short hairpin RNA (shRNA) to knock down the expression of the DAF and MCP with the aim of exploiting complement more effectively for tumor cell damage. Meanwhile, we investigated the cooperative effects of DAF and MCP on the viability and migration, moreover the proliferation of ME180 cell. RESULTS: The results showed that shRNA inhibition of DAF and MCP expression enhanced complement-dependent cytolysis (CDC) up to 39% for MCP and up to 36% for DAF, and the combined inhibition of both regulators yielded further additive effects in ME180 cells. Thus, the activities of DAF and MCP, when present together, are greater than the sum of the two protein individually. CONCLUSION: These data indicated that combined DAF and MCP shRNA described in this study may offer an additional alternative to improve the efficacy of antibody-and complement-based cancer immunotherapy.

Role of decay-accelerating factor in regulating survival of human cervical cancer cells.

BACKGROUND: Decay-accelerating factor (DAF) is one of the key molecules involved in cell protection against autologous complement, which restricts the action of complement at critical stages of the cascade reaction. The effect of DAF on the survival of human cervical cancer cell (ME180) has not been demonstrated. METHODS: In this study we applied, for the first time, small interference RNA (siRNA) to knock down the expression of the DAF with the aim of exploiting complement more effectively for tumor cell damage. Meanwhile, we investigated the effects of DAF on the viability and migration, moreover the proliferation of ME180 cell. RESULTS: The results showed that the expression of DAF was significantly increased in human cervical cancer tissues. SiRNA inhibition of DAF expression enhanced complement-dependent cytolysis up to 32% in ME180 cells, which contributed to the control of C3 activation and increased the cells viability, migration and augment the number of ME180 cells. CONCLUSION: These data indicated that DAF siRNA described in this study may offer an additional alternative to improve the efficacy of antibody- and complement-based cancer immunotherapy.

Bioadsorption of methyl violet from aqueous solution onto Pu-erh tea powder.

Chinese unique Pu-erh tea powder (PTP), with leached active ingredients, was used here to adsorb methyl violet (MV), a cationic dye. The effects of several variables on the removal of methyl violet were studied at 25 degrees C, including pH value, contact time, quantity of the adsorbent, initial concentration, and particle size of the adsorbent. The results showed that the particle size of the adsorbent significantly affected the adsorption process, and the nano-sized PTP particles had the best adsorption efficiency. The equilibrium data was analyzed using Langmuir, Freundlich, and Tempkin isotherms models. The pseudo-second-order kinetics model best explained the MV adsorption by PTP of any particle size. The intra-particle diffusion model was also used to analyze the adsorption process, and it was found that smaller adsorbent particles had a bigger boundary layer effect.

[Small interfering RNA-mediated COX-2 gene silencing inhibits the proliferation and migration of human ovarian cancer cell line CAOV-3].

OBJECTIVE: To investigate the changes in the proliferation and migration of human ovarian cancer cells (CAOV-3) after knocking down COX-2 gene by RNA interference. METHODS: The recombinant plasmid of pGenesil-1-siRNA-COX-2 was constructed and transfected into CAOV-3 cells. The transcription of COX-2 gene was detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the protein expression of COX-2 was determined by Western blotting . MTT assay was used to investigate the proliferation of the transfected CAOV-3 cells, and the cell migration was evaluated using a transwell migration assay. RESULTS: COX-2 mRNA and protein levels were significantly reduced after pGenesil-1-siRNA-COX-2 transfection into CAOV-3 cells, which showed obvious reduction in the cell proliferation and migration. CONCLUSION: RNA interference allows obvious COX-2 gene knocking down in human ovarian cancer cells to result in lowered cell growth rate and migration ability. COX-2 gene may become a new therapeutic target for ovarian cancer.