ABSTRACT
OBJECTIVE@#To explore the relationship between TK gene expression regulated by enhanced suicide gene vector and telomerase activity in nasopharyngeal carcinoma cells.@*METHOD@#The reformed reconstructed enhanced vector, pGL3-basic-EGFP-TK-hTRETp-CMV enhancer, and hTERT mono-promoter vector, pGL3-basic-EGFP-TK-hTRETp(as controls), were transfected into telomerase(+) nasopharyngeal carcinoma 5-8F cell lines, telomerase(+) human breast cancer MCF-7 cell lines and telomerase(-) normal vascular endothelium cell lines respectively. TK gene green fluorescent protein was observed by fluorescence microscope. The expression of TK gene mRNA was measured by the real-time fluorescent quantified PCR and the telomerase activity was determined by the method of TRAP argentation in malignant tumour cells pre- and post-transfected by enhanced vector. Meanwhile the relationship between TK and telomerase was analyzed.@*RESULT@#(1) A strong TK gene fluorescent show and TK mRNA expression were displayed after the enhanced suicide gene vector was transfected into nasopharyngeal carcinoma 5-8F cell lines and human breast cancer MCF-7 cell line, which were more stronger than those of mono-promoter group, pGL3-basic-EGFP-TK-hTRETp, and ECV cells transfected by enhanced suicide gene vector. Meanwhile,real-time fluorescent quantified PCR showed that the A value of enhanced vector group was higher than that of controls. (2) Telomerase activity after transfection of enhanced vector and GCV was lower than those before by the method of TRAP argentation in nasopharyngeal carcinoma cell lines,but no change in normal control cells after transfection of enhanced vector and GCV. (3) After adding GCV, the obvious inhibitory effect of tumour cells growth induced by pGL3-basic-EGFP-TK-hTRETp-CMV enhancer were observed in nasopharyngeal carcinoma 5-8F cell lines and human breast cancer MCF-7 cell line, which was higher than those of mono-promoter, pGL3-basic-EGFP-TK-hTRETp, pGL3-basic-EGFP3 and blank controls, but without inhibitory effect in ECV cells transfected by enhanced vector.@*CONCLUSION@#TK gene expression is regulated by hTERT promoter and CMV enhancer, and then the telomerase activity is reduced and the cancer cells are specifically killed. But it is unclear how the telomerase are down-regulated by TK gene.
Subject(s)
Humans , Cell Death , Cell Line , Cell Line, Tumor , Gene Expression Regulation , Genes, Transgenic, Suicide , Genetic Vectors , Green Fluorescent Proteins , Genetics , Nasopharyngeal Neoplasms , Genetics , Metabolism , Promoter Regions, Genetic , Regulatory Sequences, Nucleic Acid , Telomerase , Genetics , Metabolism , Thymidine Kinase , Genetics , TransfectionABSTRACT
Objective:To explore the relationship between TK gene expression regulated by enhanced suicide gene vector and telomerase activity in nasopharyngeal carcinoma cells.Method:The reformed reconstructed enhanced vector, pGL3-basic-EGFP-TK-hTRETp-CMV enhancer, and hTERT mono-promoter vector, pGL3-basic-EGFP-TK-hTRETp(as controls), were transfected into telomerase(+) nasopharyngeal carcinoma 5-8F cell lines,telomerase(+) human breast cancer MCF-7 cell lines and telomerase(-) normal vascular endothelium cell lines respectively. TK gene green fluorescent protein was observed by fluorescence microscope. The expression of TK gene mRNA was measured by the real-time fluorescent quantified PCR and the telomerase activity was determined by the method of TRAP argentation in maligment tumour cells pre- and post-transfected by enhanced vector . Meanwhile the relationship beteewn TK and telomerase was analyzed.Result:①A strong TK gene fluorescent show and TK mRNA expression were displayed after the enhanced suicide gene vector was transfected into nasopharyngeal carcinoma 5-8F cell lines and human breast cancer MCF-7 cell line, which were more stronger than those of mono-promoter group,pGL3-basic-EGFP-TK-hTRETp,and ECV cells transfected by enhanced suicide gene vector. Meanwhile,real-time fluorescent quantified PCR showed that the A value of enhanced vector group was higher than that of controls. ②Telomerase activity after transfection of enhanced vector and GCV was lower than those before by the method of TRAP argentation in nasopharyngeal carcinoma cell lines,but no change in normal control cells after transfection of enhanced vector and GCV.③ After adding GCV, the obvious inhibitory effect of tumour cells growth induced by pGL3-basic-EGFP-TK-hTRETp-CMV enhancer were observed in nasopharyngeal carcinoma 5-8F cell lines and human breast cancer MCF-7 cell line, which was higher than those of mono-promoter, pGL3-basic-EGFP-TK-hTRETp,pGL3-basic-EGFP3 and blank controls, but without inhibitory effect in ECV cells transfected by enhanced vector. Conclusion:TK gene expression is regulated by hTERT promoter and CMV enhancer, and then the telomerase activity is reduced and the cancer cells are specifically killed.But it is unclear how the telomerase are down-regulated by TK gene.
ABSTRACT
1.Conclusion ABR can evaluate the function of brainstem of patients with severe traumatic brain injury in PVS and provide evidence for prognosis.
ABSTRACT
Objective To find out the difference in Multi-channel Cochlear mapping between SPrint speech processor and ESPrit speech processor (ESPrit 3G) for better guidance of the mapping.Methods Nine cases of total deafness patients (aged 2-54 years old) using SPrint changed to using ESPrit 3G after 6 to 24 months. The threshold (T-L) of electro-audiogram using different speech processor, comfortable level, sound field audiometry in various ESPrit 3G programs and questionnaire results were compared and analyzed statistically.Results Using various speech processor programs, four patients(The first group) felt satisfied with hearing effects. There was no difference comparing with SPrint. There was significantly different in T-L and C-L acquired from five patients(The second group) with two speech processors (P0.05). The results of sound field audiometry showed significant difference in the first group and the second group using programs from SPrint(P
ABSTRACT
The course of audiology is both important and difficult to the undergraduate education of otolaryngology.Through a series of reforms in teaching contents and methods of audiology,the students'effect of study were greatlyimproved,and thus these reforms were generally appreciated by both teachers and students. In conclusion, the act of theteaching reform not only advanced the students' learning enthusiasm and gumption, but also helps the development andexercise in their clinical thinking ability.
ABSTRACT
Objective To investigate the different characters between conventional frequency audiometry (125 Hz～8 kKHz) and high frequency audiometry (9～16 kHz)in the normal youth and provide the references for the clinical application of the HFA.Methods 52 male and 48 female normal-hearing subjects were tested with both conventional-frequency (0.25～8 kHz) and high-frequency (10～18 kHz) audiometry.Results Data showed that no difference between male and female in different frequencies. However, the threshold of HFA went up gradually with the frequency increasing. The average threshold of HFA was significantly higher than that of CFA and speech frequency (SFA) and had a positive correlation with both CFA and SFA. Conclusion The results of this study suggest that HFA might be used as an early indicator for CFA and SFA hearing loss resulting from acoustic trauma, ototoxicity and presbycusis.
ABSTRACT
Objective To evaluate and compare the results of air-conduct and bone-conduct auditory brainstem response(ABR)for the purpose of clinical application of the bone-conduct ABR.Methods A group of normal hearing young adults(61 ears)were measured with click stimulation air-conduct ABR and bone-conduct ABR in a soundproof chamber.Results The waveforms of bone-conduct ABR were almost the same as those of air-conduct ones with the threshold of 26.08?7.71 dB(nHL),but with a lower rate of wave derivation.There were no significant differences between male and female for both air-conduct and bone-conduct ABR testing.The threshold for bone-conduct ABR was higher than that of air-conduct one with a very high positive correlation(r=0.7740)and there were significant differences (P0.05) for the wave intervals.Conclusion The limitation of the bone-conduct ABR application and the differences from air-conduct should be considered when it was used clinically.