OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI...OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI 1640 medium containing different concentrations of nimesulide （0,12.5, 50, 100, 200, 400 μmol/L）. The MTT assay, morphological observation, electron microscopy （EM）, immunohistochemical analysis and Western blot analysis were employed to investigate the effects of nimesulide on the SGC-7901 cells and to explore possible related molecular mechanisms. RESULTS Nimesulide inhibited the growth of SGC-7901 cells and elicited typical apoptotic morphologic changes. Nimesulide also decreased NF-κB and Bcl-2 expression, but increased the level of the Bax protein. The positive rate of Bcl-2 protein expression at 0, 50, 100 and 200 μmol/L of nimesulide was 58.3±14.0%, 50.2±9.9%, 32.8±5.0% and 22.7±5.5% respectively based on immunohistochemical staining. The positive rate of Bax protein expression was 22.0±5.7%, 29.2±6.5%, 42.7±5.9% and 74.5±9.1% and the NF-κB expression was 74.2±10.9%, 61.8±7.6%, 36.7±10.9% and 17.5±12.3%, Significant differences were found between so μmol/L and 100 μmol/L and 200μmol/L. Western blot analysis also showed that the expression of NF-κB was decreased. CONCLUSION Nimesulide suppresses tumor growth and induces apoptosis by inhibiting NF-κB expression, which may be related to the overexpression of Bax relative to Bcl-2 expression.展开更多
Objective: To investigate the cytotoxic effects and the potential mechanisms of crebanine N-oxide in SGC-7901 gastric adenocarcinoma cells. Methods: The cytotoxicity of crebanine N-oxide was evaluated by 3-(4,5-dimeth...Objective: To investigate the cytotoxic effects and the potential mechanisms of crebanine N-oxide in SGC-7901 gastric adenocarcinoma cells. Methods: The cytotoxicity of crebanine N-oxide was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and cellular morphology was observed under a microscope. Cell apoptosis was determined by flow cytometry using propidium iodide staining. The expression levels of apoptotic-related proteins, cleaved caspase-3, cytochrome C, p53 and Bax, and autophagyrelated proteins p62, beclin1 and LC3 were detected by Western blotting assays. Results: Crebanine N-oxide treatment significantly inhibited the proliferation of SGC-7901 cells in a dose-dependent and timedependent manner via induction of G2-phase cell cycle arrest, apoptosis, and autophagy in SGC-7901 cells.Conclusions: Crebanine N-oxide could inhibit the growth of gastric cancer cells by promoting apoptosis and autophagy and could be used as a potential agent for treating gastric cancer.展开更多
To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric...To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric carcinoma cells was used as the target cells of infection. The virus-infected cell clones were isolated by limited dilution method. It was found that the EBV-encoded small RNA (EBER) could be detected in the infected cells. The Akata and P3HR-1 EBV infected parental cells and most of clones expressed EBNA1, but not EBNA2. Latent membrane protein (LMP-1) and LMP-2, and the Q promoter (p), but not the Cp/Wp for EBNA gene transcription was active in the infected parental cells as well as all the clones. Uninfected HSC-39 cells did not express CD21, however, Akata but not P3HR-1 EBV-infected clones expressed low level of CD21 mRNA. These results demonstrate that HSC-39 cells are susceptible to both EBV strains and EBV infects HSC-39 cells through the CD21-independent pathway. This study defines a signet ring type of gastric carcinoma cells line as a unique target cells for the study of EBV infection mechanism.展开更多
The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the transl...The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the translational initiation site of c-Ha-ras proto-oncogene (ASO-r) greatly inhibited the proliferation (55. 61%,P<0. 05) and DNA synthesis (76. 79%,P<0. 05) of MGc-803 cell line. It also inhibited the proliferation (62. 02%,P<0. 05) and DNA synthesis (76. 78%, P<0. 05) of SGc-7901 cell line. A reduction in intracellular P21 ras protein levels in MGc-803 cell line was observed 6 h after the treatment with ASO-r and maintained over 12 h. Another synthetic 15-mer targeted against the initiation codon and downstream 4 codons of c-myc proto-oncogene (ASOm) inhibited only DNA synthesis of MGc-803 cell line (71. 37%, P<0. 05). The control 15-mer did not inhibit the expression of P21 protein and proliferation of these cell lines. These experiments seemed to provide evidence that ASO-r could be effective in inhibiting the expression of c-Ha-ras proto-oncogene and controlling the growth of human gastric carcinoma cells,and that the over-expression of c-Ha-ras proto-oncogene might mainly be associated with the malignant proliferation of human gastric carcinoma cells.展开更多
AIM： To investigate the low intensity ultrasound （US）- induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. METHODS： Human ...AIM： To investigate the low intensity ultrasound （US）- induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. METHODS： Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry （FCM） with double staining of fiuorescein isothiocyanate （FITC）- Annexin V/propidium iodide （PI）. Two-dimensional electrophoresis （2DE） was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis. RESULTS： The percentage of apoptotic cells increased about 10% after US irradiation （12.0 W/cm^2, 12 h culture）, The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h.Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins （HSPs） were found to be associated with the signal process simulating the apoptosis of cells. CONCLUSION： Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum （ER） stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.展开更多
目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对...目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对VEGF m RNA表达的影响。结果 20、40、60、80、100μmol/L的隐丹参酮作用于人胃癌SGC-7901细胞6-48 h,其生长和增殖均受到一定程度的抑制;24 h为隐丹参酮对SGC-7901细胞抑制作用的最佳时间,IC50为59.11μmol/L;选取40、60和80μmol/L 3个剂量作用于人胃癌细胞SGC7901 24 h后,60和80μmol/L的隐丹参酮均可下调VEGF m RNA的表达（均P〈0.01）。结论隐丹参酮可抑制人胃癌SGC-7901细胞增殖,并能抑制VEGF mRNA的表达,提示这可能是其抗肿瘤的作用机制之一。展开更多
基金This work was supported by the grant form the Natural Science Foundation of the Education Department of Jiangsu Province of China (No. 05KJD320234 and 01KJB320011).
文摘OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI 1640 medium containing different concentrations of nimesulide （0,12.5, 50, 100, 200, 400 μmol/L）. The MTT assay, morphological observation, electron microscopy （EM）, immunohistochemical analysis and Western blot analysis were employed to investigate the effects of nimesulide on the SGC-7901 cells and to explore possible related molecular mechanisms. RESULTS Nimesulide inhibited the growth of SGC-7901 cells and elicited typical apoptotic morphologic changes. Nimesulide also decreased NF-κB and Bcl-2 expression, but increased the level of the Bax protein. The positive rate of Bcl-2 protein expression at 0, 50, 100 and 200 μmol/L of nimesulide was 58.3±14.0%, 50.2±9.9%, 32.8±5.0% and 22.7±5.5% respectively based on immunohistochemical staining. The positive rate of Bax protein expression was 22.0±5.7%, 29.2±6.5%, 42.7±5.9% and 74.5±9.1% and the NF-κB expression was 74.2±10.9%, 61.8±7.6%, 36.7±10.9% and 17.5±12.3%, Significant differences were found between so μmol/L and 100 μmol/L and 200μmol/L. Western blot analysis also showed that the expression of NF-κB was decreased. CONCLUSION Nimesulide suppresses tumor growth and induces apoptosis by inhibiting NF-κB expression, which may be related to the overexpression of Bax relative to Bcl-2 expression.
基金supported by the National Natural Science Foundation of China(NO.81760628).
文摘Objective: To investigate the cytotoxic effects and the potential mechanisms of crebanine N-oxide in SGC-7901 gastric adenocarcinoma cells. Methods: The cytotoxicity of crebanine N-oxide was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and cellular morphology was observed under a microscope. Cell apoptosis was determined by flow cytometry using propidium iodide staining. The expression levels of apoptotic-related proteins, cleaved caspase-3, cytochrome C, p53 and Bax, and autophagyrelated proteins p62, beclin1 and LC3 were detected by Western blotting assays. Results: Crebanine N-oxide treatment significantly inhibited the proliferation of SGC-7901 cells in a dose-dependent and timedependent manner via induction of G2-phase cell cycle arrest, apoptosis, and autophagy in SGC-7901 cells.Conclusions: Crebanine N-oxide could inhibit the growth of gastric cancer cells by promoting apoptosis and autophagy and could be used as a potential agent for treating gastric cancer.
文摘To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric carcinoma cells was used as the target cells of infection. The virus-infected cell clones were isolated by limited dilution method. It was found that the EBV-encoded small RNA (EBER) could be detected in the infected cells. The Akata and P3HR-1 EBV infected parental cells and most of clones expressed EBNA1, but not EBNA2. Latent membrane protein (LMP-1) and LMP-2, and the Q promoter (p), but not the Cp/Wp for EBNA gene transcription was active in the infected parental cells as well as all the clones. Uninfected HSC-39 cells did not express CD21, however, Akata but not P3HR-1 EBV-infected clones expressed low level of CD21 mRNA. These results demonstrate that HSC-39 cells are susceptible to both EBV strains and EBV infects HSC-39 cells through the CD21-independent pathway. This study defines a signet ring type of gastric carcinoma cells line as a unique target cells for the study of EBV infection mechanism.
文摘The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the translational initiation site of c-Ha-ras proto-oncogene (ASO-r) greatly inhibited the proliferation (55. 61%,P<0. 05) and DNA synthesis (76. 79%,P<0. 05) of MGc-803 cell line. It also inhibited the proliferation (62. 02%,P<0. 05) and DNA synthesis (76. 78%, P<0. 05) of SGc-7901 cell line. A reduction in intracellular P21 ras protein levels in MGc-803 cell line was observed 6 h after the treatment with ASO-r and maintained over 12 h. Another synthetic 15-mer targeted against the initiation codon and downstream 4 codons of c-myc proto-oncogene (ASOm) inhibited only DNA synthesis of MGc-803 cell line (71. 37%, P<0. 05). The control 15-mer did not inhibit the expression of P21 protein and proliferation of these cell lines. These experiments seemed to provide evidence that ASO-r could be effective in inhibiting the expression of c-Ha-ras proto-oncogene and controlling the growth of human gastric carcinoma cells,and that the over-expression of c-Ha-ras proto-oncogene might mainly be associated with the malignant proliferation of human gastric carcinoma cells.
基金The National Natural Science Foundation of China (No. 30630024)the Key Project of Ministry of Education (No. 705046)the Doctoral Foundation of Xi’an Jiaotong University (grants No. DFXJTU2005-05)
文摘AIM： To investigate the low intensity ultrasound （US）- induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. METHODS： Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry （FCM） with double staining of fiuorescein isothiocyanate （FITC）- Annexin V/propidium iodide （PI）. Two-dimensional electrophoresis （2DE） was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis. RESULTS： The percentage of apoptotic cells increased about 10% after US irradiation （12.0 W/cm^2, 12 h culture）, The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h.Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins （HSPs） were found to be associated with the signal process simulating the apoptosis of cells. CONCLUSION： Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum （ER） stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.
文摘目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对VEGF m RNA表达的影响。结果 20、40、60、80、100μmol/L的隐丹参酮作用于人胃癌SGC-7901细胞6-48 h,其生长和增殖均受到一定程度的抑制;24 h为隐丹参酮对SGC-7901细胞抑制作用的最佳时间,IC50为59.11μmol/L;选取40、60和80μmol/L 3个剂量作用于人胃癌细胞SGC7901 24 h后,60和80μmol/L的隐丹参酮均可下调VEGF m RNA的表达（均P〈0.01）。结论隐丹参酮可抑制人胃癌SGC-7901细胞增殖,并能抑制VEGF mRNA的表达,提示这可能是其抗肿瘤的作用机制之一。
