AIM: To explore the feasibility of enhancing apoptosis-inducing effects of chemotherapeutic drugs on human gastric cancer cells by stable transfection of extrinsic Smac gene. METHODS: After Smac gene was transferred i...AIM: To explore the feasibility of enhancing apoptosis-inducing effects of chemotherapeutic drugs on human gastric cancer cells by stable transfection of extrinsic Smac gene. METHODS: After Smac gene was transferred into gastric cancer cell line MKN-45, subclone cells were obtained by persistent G_(418) selection. Cellular Smac gene expression was determined by RT-PCR and Western blotting. After treatment with mitomycin (MMC) as an apoptotic inducer, in vitro cell growth activities were investigated by trypan blue-staining method and MTT colorimetry. Cell apoptosis and its rates were determined by electronic microscopy, annexin V-FTTC and propidium iodide staining flow cytometry. Cellular caspase-3 protein expression and its activities were assayed by Western blotting and colorimetry. RESULTS: When compared with MKN-45 cells, the selected subclone cell line MKN-45/Smac had significantly higher Smac mRNA (3.12±0.21 vs 0.82±0.14, t=7.52, P＜0.01) and protein levels (4.02±0.24 vs0.98±0.11, t=8.32, P＜0.01). After treatment with 10 μg/mL MMC for 6-24 h, growth inhibition rate of MKN-45/Smac (15.8±1.2-54.8±2.9%) was significantly higher than that of MKN-45 (5.8±0.4-24.0±1.5%, t=6.42, P＜0.01). Partial MKN-45/Smac cancer cells presented characteristic morphological changes of apoptosis under the electronic microscope with an apoptosis rate of 36.4±2.1%, which was significantly higher than that of MKN-45 (15.2±0.8%, t=9.25, P＜0.01). Compared with MKN-45, caspase-3 expression levels in MKN-45/Smac were improved significantly (3.39±0.42 vs0.96±0.14, t=8.63, P＜0.01), while its activities were 3.25 times as many as those of MKN-45 (0.364±0.010 vs0.112±0.007, t=6.34, P＜0.01). CONCLUSION: Stable transfection of extrinsic Smac gene and its over-expression in gastric cancer cell line can significantly enhance cellular caspase-3 expression and activities, ameliorate apoptosis-inducing effects of mitomycin C on cancer cells, which is a novel strategy to improve chemotherapeutic effects on gastric cancer.展开更多
AIM： To investigat the relation between hepatotoxicity of halothane and sevoflurane and altered hepatic calcium homeostasis in enzyme-induced hypoxic rats. METHODS： Forty-eight rats were pretreated with phenobarbita...AIM： To investigat the relation between hepatotoxicity of halothane and sevoflurane and altered hepatic calcium homeostasis in enzyme-induced hypoxic rats. METHODS： Forty-eight rats were pretreated with phenobarbital and randomly divided into six groups （eight in each group） and exposed to O2/N2/1.2 MAC anesthetics for 1 h： normal control （NC）, 21% O2/79% N2; hypoxic control （HC）, 14% O2/86% N2; normal sevoflurane （NS）, 21% O2/ N2/1.2MAC sevoflurane; hypoxic sevoflurane （HS）, 14% O2/N2/1.2MAC sevoflurane; normal halothane （NH）21%O2/79%N2/1.2MAC halothane; hypoxic halothane （HH）, 14%O2/N2/1.2MAC halothane. Liver specimens and blood were taken 24 h after exposure to calcium and determined by EDX microanalysis. RESULTS： The liver of all rats given halothane （14% O2） had extensive centrilobular necrosis and denaturation. Morphologic damage was accompanied with an increase in serum glutarnic pyruvic transminase. In groups NH and HH, more calcium was precipitated in cytoplasm and mitochondria. CONCLUSION： These results suggest that halothane increases cytosolic Ca^2＋ concentration in hepatocytes. Elevation in Ca^2＋ concentration is implicated in the mechanism of halothane-induced hepatotoxicity. sevoflurane is less effective in affecting hepatic calcium homeostasis than halothane.展开更多
Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixt...Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixty male Sprague-Dawley rats were divided equally into two groups: GDNF group and control group. The SCI model was established according to the method of Nystrom, and then the DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA complexes were injected into the injured spinal cord. The expression of GDNF cDNA 1 week after injection was detected by RT-PCR and fluorescence microscope. We observed the remaining motoneurons in the anterior horn and the changes of cholinesterase (CHE) and acid phosphatase (ACP) activity using Nissl and enzyme histochemistry staining. The locomotion function of hind limbs of rats was evaluated using inclined plane test and BBB locomotor scale. Results: RT-PCR and fluorescence observation confirmed the presence of expression of GDNF cDNA 1 week and 4 weeks after injection. At 1, 2, 4 weeks after SCI, the number of motoneurons in the anterior horn in GDNF group ((20.4)±(3.2), (21.7)±(3.6), (22.5)±(3.4)) was more than that in control group ((16.8)±(2.8), (17.3)±(2.7), (18.2)±(3.2), P<(0.05)). At 1, 2 weeks after SCI, the mean gray of the CHE-stained spinal motoneurons in GDNF group ((74.2)±(25.8), (98.7)±(31.6)) was less than that in control group ((98.5)±(32.2), (134.6)±(45.2), P<(0.01)), and the mean gray of ACP in GDNF group ((84.5)±(32.6), (79.5)±(28.4)) was more than that in control group ((61.2)±(24.9), (52.6)±(19.9), P<(0.01)). The locomotion functional scales in GDNF group were higher than that in control group within 1 to 4 weeks after SCI (P<(0.05)). Conclusions: GDNF gene transfer in vivo can protect motoneurons from death and degeneration induced by incompleted spinal cord injury as well as enhance locomotion functional restoration of hind limbs. These results suggest that liposome-mediated delivery of GDNF cDNA might be a practical method for treating traumatic spinal cord injury.展开更多
文摘AIM: To explore the feasibility of enhancing apoptosis-inducing effects of chemotherapeutic drugs on human gastric cancer cells by stable transfection of extrinsic Smac gene. METHODS: After Smac gene was transferred into gastric cancer cell line MKN-45, subclone cells were obtained by persistent G_(418) selection. Cellular Smac gene expression was determined by RT-PCR and Western blotting. After treatment with mitomycin (MMC) as an apoptotic inducer, in vitro cell growth activities were investigated by trypan blue-staining method and MTT colorimetry. Cell apoptosis and its rates were determined by electronic microscopy, annexin V-FTTC and propidium iodide staining flow cytometry. Cellular caspase-3 protein expression and its activities were assayed by Western blotting and colorimetry. RESULTS: When compared with MKN-45 cells, the selected subclone cell line MKN-45/Smac had significantly higher Smac mRNA (3.12±0.21 vs 0.82±0.14, t=7.52, P＜0.01) and protein levels (4.02±0.24 vs0.98±0.11, t=8.32, P＜0.01). After treatment with 10 μg/mL MMC for 6-24 h, growth inhibition rate of MKN-45/Smac (15.8±1.2-54.8±2.9%) was significantly higher than that of MKN-45 (5.8±0.4-24.0±1.5%, t=6.42, P＜0.01). Partial MKN-45/Smac cancer cells presented characteristic morphological changes of apoptosis under the electronic microscope with an apoptosis rate of 36.4±2.1%, which was significantly higher than that of MKN-45 (15.2±0.8%, t=9.25, P＜0.01). Compared with MKN-45, caspase-3 expression levels in MKN-45/Smac were improved significantly (3.39±0.42 vs0.96±0.14, t=8.63, P＜0.01), while its activities were 3.25 times as many as those of MKN-45 (0.364±0.010 vs0.112±0.007, t=6.34, P＜0.01). CONCLUSION: Stable transfection of extrinsic Smac gene and its over-expression in gastric cancer cell line can significantly enhance cellular caspase-3 expression and activities, ameliorate apoptosis-inducing effects of mitomycin C on cancer cells, which is a novel strategy to improve chemotherapeutic effects on gastric cancer.
基金Supported by Military Medical Science Found of China, No.39400126
文摘AIM： To investigat the relation between hepatotoxicity of halothane and sevoflurane and altered hepatic calcium homeostasis in enzyme-induced hypoxic rats. METHODS： Forty-eight rats were pretreated with phenobarbital and randomly divided into six groups （eight in each group） and exposed to O2/N2/1.2 MAC anesthetics for 1 h： normal control （NC）, 21% O2/79% N2; hypoxic control （HC）, 14% O2/86% N2; normal sevoflurane （NS）, 21% O2/ N2/1.2MAC sevoflurane; hypoxic sevoflurane （HS）, 14% O2/N2/1.2MAC sevoflurane; normal halothane （NH）21%O2/79%N2/1.2MAC halothane; hypoxic halothane （HH）, 14%O2/N2/1.2MAC halothane. Liver specimens and blood were taken 24 h after exposure to calcium and determined by EDX microanalysis. RESULTS： The liver of all rats given halothane （14% O2） had extensive centrilobular necrosis and denaturation. Morphologic damage was accompanied with an increase in serum glutarnic pyruvic transminase. In groups NH and HH, more calcium was precipitated in cytoplasm and mitochondria. CONCLUSION： These results suggest that halothane increases cytosolic Ca^2＋ concentration in hepatocytes. Elevation in Ca^2＋ concentration is implicated in the mechanism of halothane-induced hepatotoxicity. sevoflurane is less effective in affecting hepatic calcium homeostasis than halothane.
文摘Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixty male Sprague-Dawley rats were divided equally into two groups: GDNF group and control group. The SCI model was established according to the method of Nystrom, and then the DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA complexes were injected into the injured spinal cord. The expression of GDNF cDNA 1 week after injection was detected by RT-PCR and fluorescence microscope. We observed the remaining motoneurons in the anterior horn and the changes of cholinesterase (CHE) and acid phosphatase (ACP) activity using Nissl and enzyme histochemistry staining. The locomotion function of hind limbs of rats was evaluated using inclined plane test and BBB locomotor scale. Results: RT-PCR and fluorescence observation confirmed the presence of expression of GDNF cDNA 1 week and 4 weeks after injection. At 1, 2, 4 weeks after SCI, the number of motoneurons in the anterior horn in GDNF group ((20.4)±(3.2), (21.7)±(3.6), (22.5)±(3.4)) was more than that in control group ((16.8)±(2.8), (17.3)±(2.7), (18.2)±(3.2), P<(0.05)). At 1, 2 weeks after SCI, the mean gray of the CHE-stained spinal motoneurons in GDNF group ((74.2)±(25.8), (98.7)±(31.6)) was less than that in control group ((98.5)±(32.2), (134.6)±(45.2), P<(0.01)), and the mean gray of ACP in GDNF group ((84.5)±(32.6), (79.5)±(28.4)) was more than that in control group ((61.2)±(24.9), (52.6)±(19.9), P<(0.01)). The locomotion functional scales in GDNF group were higher than that in control group within 1 to 4 weeks after SCI (P<(0.05)). Conclusions: GDNF gene transfer in vivo can protect motoneurons from death and degeneration induced by incompleted spinal cord injury as well as enhance locomotion functional restoration of hind limbs. These results suggest that liposome-mediated delivery of GDNF cDNA might be a practical method for treating traumatic spinal cord injury.
