To construct a mutant pEGFP- hTERTexpression vector, to observe its steady expression intransfected human bladder carcinoma cell line T24 and its role in molecular regulatory mechanisms of telomerase, and to provide a...To construct a mutant pEGFP- hTERTexpression vector, to observe its steady expression intransfected human bladder carcinoma cell line T24 and its role in molecular regulatory mechanisms of telomerase, and to provide a new target gene for bladder cancer. Methods: PCR amplification was performed by using primers basedon the known gene sequence of hTERT. PCR productionwas cloned into plasmid pGEMT-T easy and the sequenceof mutant hTERT gene was analyzed. A recombinantmutant hTERT vector (pEGFP-hTERT) was constructed at the EcoR I and Sal I sites of the pEGFP-C1 vector. Aftertransfecting the fusion gene into bladder carcinoma cell line T24 by calcium phosphate-DNA coprecipitation, the steady expression of GFP-hTERT fusion protein was tested by fluorescent light microscopy. The proliferation changes ofbladder carcinoma cell line T24 were detected by lightmicroscopy and senescence correlated b-galactosidase staining. Results: Identification of pEGFP-hTERT byenzyme digestion showed that mutant hTERT fragment had been cloned into EcoR I and Sal I sites of the pEGFP-C1 vector. The steady expression of GFP-hTERT fusion protein was localized in the nucleus of transfected cells. Expression of senescence-associated b-galactosidase in transfected cells gradually increased with extended cultured time and cellgrowth was suppressed. Conclusion: The mutant-type hTERT gene suppresses the proliferation of bladder carcinoma cell line T24 by competitive effect on telomerase activity. This suggests that hTERT gene might be a suitable gene target for bladder cancer therapy.展开更多
Objective To study the inhibitory effects of melatonin and its inhibitory mechanism on the growth of human bladder carcinoma T24. Methods The inhibitory effects of melatonin with various concentrations on the human ...Objective To study the inhibitory effects of melatonin and its inhibitory mechanism on the growth of human bladder carcinoma T24. Methods The inhibitory effects of melatonin with various concentrations on the human bladder carcinoma T24 lines in vitro were determined by MTT assay. The mechanism of the inhibition was observed by flow cytometry (FCM) and transmission electron microscopy (TEM). Results The 30% inhibition concentration (IC 30) value was 0.71 mmol·L -1 and the 50% inhibition concentration (IC 50) value was 1.20 mmol·L -1. The population doubling time of T24 cells treated with melatonin at 0.71 mmol·L -1 was 43.2 hours, which was significant different from that of 34.6 hours of the control group. Using FCM, we found that the cell percentage increased during the G 1 phase, but decreased during the S stage. The degenerated ultra-structure of the cell treated with melatonin was also observed by TEM. Conclusion The results suggest that melatonin can inhibit the growth of human bladder carcinoma T24. The inhibitory effects of melatonin might be the prolonging of the staging from G 1 to S in the cell cycle.展开更多
基金This work was supported by the grants from the National Natural Science Foundation of China (No. 39870783) and the National 973 Project of China (No.G2000057001)
文摘To construct a mutant pEGFP- hTERTexpression vector, to observe its steady expression intransfected human bladder carcinoma cell line T24 and its role in molecular regulatory mechanisms of telomerase, and to provide a new target gene for bladder cancer. Methods: PCR amplification was performed by using primers basedon the known gene sequence of hTERT. PCR productionwas cloned into plasmid pGEMT-T easy and the sequenceof mutant hTERT gene was analyzed. A recombinantmutant hTERT vector (pEGFP-hTERT) was constructed at the EcoR I and Sal I sites of the pEGFP-C1 vector. Aftertransfecting the fusion gene into bladder carcinoma cell line T24 by calcium phosphate-DNA coprecipitation, the steady expression of GFP-hTERT fusion protein was tested by fluorescent light microscopy. The proliferation changes ofbladder carcinoma cell line T24 were detected by lightmicroscopy and senescence correlated b-galactosidase staining. Results: Identification of pEGFP-hTERT byenzyme digestion showed that mutant hTERT fragment had been cloned into EcoR I and Sal I sites of the pEGFP-C1 vector. The steady expression of GFP-hTERT fusion protein was localized in the nucleus of transfected cells. Expression of senescence-associated b-galactosidase in transfected cells gradually increased with extended cultured time and cellgrowth was suppressed. Conclusion: The mutant-type hTERT gene suppresses the proliferation of bladder carcinoma cell line T24 by competitive effect on telomerase activity. This suggests that hTERT gene might be a suitable gene target for bladder cancer therapy.
文摘Objective To study the inhibitory effects of melatonin and its inhibitory mechanism on the growth of human bladder carcinoma T24. Methods The inhibitory effects of melatonin with various concentrations on the human bladder carcinoma T24 lines in vitro were determined by MTT assay. The mechanism of the inhibition was observed by flow cytometry (FCM) and transmission electron microscopy (TEM). Results The 30% inhibition concentration (IC 30) value was 0.71 mmol·L -1 and the 50% inhibition concentration (IC 50) value was 1.20 mmol·L -1. The population doubling time of T24 cells treated with melatonin at 0.71 mmol·L -1 was 43.2 hours, which was significant different from that of 34.6 hours of the control group. Using FCM, we found that the cell percentage increased during the G 1 phase, but decreased during the S stage. The degenerated ultra-structure of the cell treated with melatonin was also observed by TEM. Conclusion The results suggest that melatonin can inhibit the growth of human bladder carcinoma T24. The inhibitory effects of melatonin might be the prolonging of the staging from G 1 to S in the cell cycle.
