AIM： To investigate whether activin regulates the cell proliferation of human gastric cancer cell line SNU-16 through the mRNA changes in activin receptors, Smads and p21^CIP1/WAF1. METHODS： The human gastric cancer...AIM： To investigate whether activin regulates the cell proliferation of human gastric cancer cell line SNU-16 through the mRNA changes in activin receptors, Smads and p21^CIP1/WAF1. METHODS： The human gastric cancer cell lines were cultured, RNAs were purified, and RT-PCRs were carried out with specifically designed primer for each gene. Among them, the two cell lines SNU-5 and SNU-16 were cultured with activin A for 24, 48 and 72 h. The cell proliferation was measured by MTT assay. For SNU-16, changes in ActRIA, ActRIB, ActRIIA, ActRIIB, Smad2, Smad4, Smad7, and p21^CIP1/WAF1 mRNAs were detected with RT-PCR after the cells were cultured with activin A for 24, 48 and 72 h. RESULTS： The proliferation of SNU-16 cells was down regulated by activin A whereas other cells showed no change. Basal level of inhibin/activin subunits, activin receptors, Smads, and p21^CIP1/WAF1 except for activin βB mRNAs was observed to have differential expression patterns in the human gastric cancer cell lines, AGS, KATO III, SNU-1, SNU-5, SNU-16, SNU-484, SNU-601, SNU-638, SNU-668, and SNU-719. Interestingly, significantly higher expressions of ActR IIA and IIB mRNAs were observed in SNU-16 cells when compared to other cells. After activin treatment, ActR IA, IB, and IIA mRNA levels were decreased whereas ActR IIB mRNA level increased in SNU-16 cells. Smad4 mRNA increased for up to 48 h whereas Smad7 mRNA increased sharply at 24 h and returned to the initial level at 48 h in SNU-16 cells. In addition, expression of the p21^CIP1/WAF1 the mitotic inhibitor, peaked at 72 h after activin treatment in SNU-16 cells. CONCLUSION： Our results suggest that inhibition of cell growth by activin is regulated by the negative feedback effect of Smad7 on the activin signaling pathway, and is mediated through p21^CIP1/WAF1 activation in SNU-16 cells.展开更多
AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein(AFP)-producing hu-...AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein(AFP)-producing hu-man gastric cancer cells(h-GCCs) and h-hepatocytes as donor cells in a transgenic mouse line expressing urokinase-type plasminogen activator(uPA) driven by the albumin enhancer/promoter crossed with a severe combined immunodeficient(SCID) mouse line(uPA/SCID mice).Host mice were divided into two groups(A and B).Group A mice were transplanted with h-GCCs alone,and group B mice were transplanted with h-GCCs and h-hepatocytes together.The replacement index(RI),which is the ratio of transplanted h-GCCs and h-hepatocytes that occupy the examined area of a histological section,was estimated by measuring h-AFP and h-albumin concentrations in sera,respectively,as well as by immunohistochemical analyses of h-AFP and human cytokeratin 18 in histological sections.RESULTS:The h-GCCs successfully engrafted,repopulated,and colonized the livers of mice in group A(RI = 22.0% ± 2.6%).These mice had moderately differentiated adenocarcinomatous lesions with disrupted glandular structures,which is a characteristics feature of gastric cancers.The serum h-AFP level reached 211.0 ± 142.2 g/mL(range,7.1-324.2 g/mL).In group B mice,the h-GCCs and h-hepatocytes independently engrafted,repopulated the host liver,and developed colonies(RI = 12.0% ± 6.8% and 66.0% ± 12.3%,respectively).h-GCC colonies also showed typical adenocarcinomatous glandular structures around the h-hepatocyte-colonies.These mice survived for the full 56 day-study and did not exhibit any metastasis of h-GCCs in the extrahepatic regions during the observational period.The mice with an h-hepatocyte-repopulated liver possessed metastasized h-GCCs and therefore could be a useful humanized liver animal model for studying liver cancer metastasis in vivo.CONCLUSION:A novel animal model of human liver cancer metastasis was established using the uPA/SCID mouse line.This model could be useful for in vivo testing of anti-cancer drugs and for studying the mechanisms of human liver cancer metastasis.展开更多
Objective To preliminarily explore the effects of human microRNA-181a on migration of gastric cancer cells and its mechanism.Methods The expression of miRNA-181a-5p in gastric cancer cell line GC9811 and peritoneal hi...Objective To preliminarily explore the effects of human microRNA-181a on migration of gastric cancer cells and its mechanism.Methods The expression of miRNA-181a-5p in gastric cancer cell line GC9811 and peritoneal high metastasis gastric cancer cell line GC9811-P were tested by quantitative real-time polymerase chain reaction(qRT-PCR).GC9811 cell line was展开更多
Changes in the surface structure of cell membrane and the contents of membrane pro- teins and nuclear DNA of human gastric cancer (BGC-823) cells treated with organotin compound (Et_2SnCl_2phen) were studied with a sc...Changes in the surface structure of cell membrane and the contents of membrane pro- teins and nuclear DNA of human gastric cancer (BGC-823) cells treated with organotin compound (Et_2SnCl_2phen) were studied with a scanning electron microscope (SEM),a scanning tunneling,micro- scope (STM),and a cytofluorophotometer.It was found that Et_2SnCl_2Phen not only inhibited the cell growth but also remarkably changed the surface structure of the membrane of cancer cells.The surface of Et_2SnCl_2phen treated cancer cells was relatively smooth and showed fewer microvilli under SEM. STM images showed an uneven and loose distribution of the surface of the cell.In comparison with the untreated cancer cells,there was an evident decrease in the content of membrane proteins and nuclear DNA in Et_2SnCl_2phen treated cells.展开更多
基金Supported by the Research Fund 2003 from the Catholic University of Korea
文摘AIM： To investigate whether activin regulates the cell proliferation of human gastric cancer cell line SNU-16 through the mRNA changes in activin receptors, Smads and p21^CIP1/WAF1. METHODS： The human gastric cancer cell lines were cultured, RNAs were purified, and RT-PCRs were carried out with specifically designed primer for each gene. Among them, the two cell lines SNU-5 and SNU-16 were cultured with activin A for 24, 48 and 72 h. The cell proliferation was measured by MTT assay. For SNU-16, changes in ActRIA, ActRIB, ActRIIA, ActRIIB, Smad2, Smad4, Smad7, and p21^CIP1/WAF1 mRNAs were detected with RT-PCR after the cells were cultured with activin A for 24, 48 and 72 h. RESULTS： The proliferation of SNU-16 cells was down regulated by activin A whereas other cells showed no change. Basal level of inhibin/activin subunits, activin receptors, Smads, and p21^CIP1/WAF1 except for activin βB mRNAs was observed to have differential expression patterns in the human gastric cancer cell lines, AGS, KATO III, SNU-1, SNU-5, SNU-16, SNU-484, SNU-601, SNU-638, SNU-668, and SNU-719. Interestingly, significantly higher expressions of ActR IIA and IIB mRNAs were observed in SNU-16 cells when compared to other cells. After activin treatment, ActR IA, IB, and IIA mRNA levels were decreased whereas ActR IIB mRNA level increased in SNU-16 cells. Smad4 mRNA increased for up to 48 h whereas Smad7 mRNA increased sharply at 24 h and returned to the initial level at 48 h in SNU-16 cells. In addition, expression of the p21^CIP1/WAF1 the mitotic inhibitor, peaked at 72 h after activin treatment in SNU-16 cells. CONCLUSION： Our results suggest that inhibition of cell growth by activin is regulated by the negative feedback effect of Smad7 on the activin signaling pathway, and is mediated through p21^CIP1/WAF1 activation in SNU-16 cells.
基金Supported by CLUSTER-Yoshizato Project and the National Hospital Organization Nagasaki Medical Center
文摘AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein(AFP)-producing hu-man gastric cancer cells(h-GCCs) and h-hepatocytes as donor cells in a transgenic mouse line expressing urokinase-type plasminogen activator(uPA) driven by the albumin enhancer/promoter crossed with a severe combined immunodeficient(SCID) mouse line(uPA/SCID mice).Host mice were divided into two groups(A and B).Group A mice were transplanted with h-GCCs alone,and group B mice were transplanted with h-GCCs and h-hepatocytes together.The replacement index(RI),which is the ratio of transplanted h-GCCs and h-hepatocytes that occupy the examined area of a histological section,was estimated by measuring h-AFP and h-albumin concentrations in sera,respectively,as well as by immunohistochemical analyses of h-AFP and human cytokeratin 18 in histological sections.RESULTS:The h-GCCs successfully engrafted,repopulated,and colonized the livers of mice in group A(RI = 22.0% ± 2.6%).These mice had moderately differentiated adenocarcinomatous lesions with disrupted glandular structures,which is a characteristics feature of gastric cancers.The serum h-AFP level reached 211.0 ± 142.2 g/mL(range,7.1-324.2 g/mL).In group B mice,the h-GCCs and h-hepatocytes independently engrafted,repopulated the host liver,and developed colonies(RI = 12.0% ± 6.8% and 66.0% ± 12.3%,respectively).h-GCC colonies also showed typical adenocarcinomatous glandular structures around the h-hepatocyte-colonies.These mice survived for the full 56 day-study and did not exhibit any metastasis of h-GCCs in the extrahepatic regions during the observational period.The mice with an h-hepatocyte-repopulated liver possessed metastasized h-GCCs and therefore could be a useful humanized liver animal model for studying liver cancer metastasis in vivo.CONCLUSION:A novel animal model of human liver cancer metastasis was established using the uPA/SCID mouse line.This model could be useful for in vivo testing of anti-cancer drugs and for studying the mechanisms of human liver cancer metastasis.
文摘Objective To preliminarily explore the effects of human microRNA-181a on migration of gastric cancer cells and its mechanism.Methods The expression of miRNA-181a-5p in gastric cancer cell line GC9811 and peritoneal high metastasis gastric cancer cell line GC9811-P were tested by quantitative real-time polymerase chain reaction(qRT-PCR).GC9811 cell line was
文摘Changes in the surface structure of cell membrane and the contents of membrane pro- teins and nuclear DNA of human gastric cancer (BGC-823) cells treated with organotin compound (Et_2SnCl_2phen) were studied with a scanning electron microscope (SEM),a scanning tunneling,micro- scope (STM),and a cytofluorophotometer.It was found that Et_2SnCl_2Phen not only inhibited the cell growth but also remarkably changed the surface structure of the membrane of cancer cells.The surface of Et_2SnCl_2phen treated cancer cells was relatively smooth and showed fewer microvilli under SEM. STM images showed an uneven and loose distribution of the surface of the cell.In comparison with the untreated cancer cells,there was an evident decrease in the content of membrane proteins and nuclear DNA in Et_2SnCl_2phen treated cells.
