A survey of seroepidemiology of toxoplasmosis

The article reports the result of serological investigation on toxoplasmosis among human,animaland fowl populations in Huimin District,Shandong Province.2269 samples from 1471 people,133pigs,343 sheeps,127 goats,75 chickens and 120 rabbits were tested by IHA method.There were 7％positives found in human,2.5～11.3％ in domestic animals and fowls.with the highest incicencein pigs.There are marked difference in incidences between the group of farmers,cadres and the group     

Acknowledgements to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and timeto the peer review,a critical process to ensure the qualityof World Journal of Gastroenterology.The editors andauthors of the articles submitted to the joumal are gratefulto the following reviewers for evaluating the articles(including those were published and those were rejectedin this issue) during the last editing period of time.     

Acknowledgments to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and time to the peer review, a critical process to ensure the quality of World Journal of Gastroenterology. The editors and authors of the articles submitted to the journal are grateful to the following reviewers for evaluating the articles (including those were published and those were rejected in this issue) during the last editing period of time.     

Acknowledgements to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and timeto the peer review,a critical process to ensure the qualityof World Journal of Gastroenterology.The editors andauthors of the articles submitted to the journal are gratefulto the following reviewers for evaluating the articles(including those were published and those were rejectedin this issue) during the last editing period of time.     

Acknowledgments to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and time to the peer review,a critical process to ensure the quality of World Journal of Gastroenterology. The editors and authors of the articles submitted to the journal are grateful to the following reviewers for evaluating the articles (including those published in this issue and those rejected for this issue) during the last editing time period.     

Acknowledgments to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and time to the peer review, a critical process to ensure the quality of World Journal of Gastroenterology. The editors and authors of the articles submitted to the journal are grateful to the following reviewers for evaluating the articles (including those were published and those were rejected in this issue) during the last editing period of time.     

Acknowledgements to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and time to the peer review, a critical process to ensure the quality of World Journal of Gastroenterology. The editors and authors of the articles submitted to the journal are grateful to the following reviewers for evaluating the articles (including those were published and those were rejected in this issue) during the last editing period of time.     

Acknowledgments to Reviewers of World Journal of Gastroenterology

Many reviewers have contributed their expertise and time to the peer review, a critical process to ensure the quality of World Journal of Gastroenterology. The editors and authors of the articles submitted to the journal are grateful to the following reviewers for evaluating the articles (including those were published and those were rejected in this issue) during the last editing period of time.     

Inhibitory effect of caffeic acid phenethyl ester on the growth of SW480 colorectal tumor cells involves β-catenin associated signaling pathway down-regulation

AIM: To study the anti-tumor effect of caffeic acid phenethyl ester (CAPE) and the influence of CAPE on β-catenin associated signaling pathway in SW480colorectal cancer (CRC) cells.METHODS: SW480 cells were treated with CAPE at serial concentrations. The proliferative status of cells was measured by methabenzthiazuron (MTT) assay. Cell cycle and cell apoptosis were analyzed using flow cytometry (FCM). Western blotting assay was used to evaluate the protein level of β-catenin, c-myc and cyclinD1.β-catenin localization was determined by indirect immunofluorescence.RESULTS: CAPE displayed a strong inhibitory effect in a significant dose- and time-dependent manner on SW480cell growth. FCM analysis showed that the ratio of G0/G1 phase cells increased, S phase ratio decreased and apoptosis rate increased after SW480 cells were exposed to CAPE for 24 h. Pretreatment of SW480 cells with CAPE significantly suppressed β-catenin, c-myc and cyclinD1protein expression. CAPE treatment was associated with decreased accumulation of β-catenin protein in nucleus and cytoplasm, and concurrently increased its accumulation on the surface of cell membrane.CONCLUSION: CAPE can inhibit SW480 cell proliferation by inducing cell cycle arrest and apoptosis. Decreased β-catenin and the associated signaling pathway target gene expression may mediate the anti-tumor effects of CAPE.     

ShRNA-mediated gene silencing of β-catenin inhibits growt of human colon cancer cells

AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry. RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level. The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing. CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.     

Effect of caffeic acid phenethyl ester on proliferation and apoptosis of colorectal cancer cells in vitro

ABM: To study the effect of caffeic add phenethyl ester (CAPE) on proliferation, cell cycle, apoptosis and expression of β-catenin in cultured human colorectal cancer (CRC) cell line HCT116. METHODS: HCT116 cells were treated with CAPE at serial concentrations of 80,40,20,10,5,2.5 mg/L. The proliferative status of HCT116 cells was measured by using methaben-zthiazuron (MTT) assay. Cell cycle was analyzed by using flow cytometry (FCM) with propidium iodide (PI) labeling method. The rate of apoptosis was detected by using FCM with annexin V-FITC and PI double labeling method, β-catenin levels were determined by Western blotting, β-catenin localization in HCT116 was determined by indirect immunofluorescence. RESULTS: After HCT116 cells were exposed to CAPE (80, 40, 20, 10, 5, and 2.5 mg/L) for 24, 48, 72, 96 h, CAPE displayed a strong growth inhibitory effect in a dose- and time-dependent manner against HCT116 cells. FCM analysis showed that the ratio of G0/G1 phase cells increased, S phase ratio decreased and apoptosis rate increased after HCT116 cells were exposed to CAPE (10, 5, and 2.5 mg/L) for 24 h. CAPE treatment was associated with decreased cytoplasmic β-catenin, nuclear p-catenin and a concurrent increase in β-catenin protein expression at cell-cell junctions. CONCLUSION: CAPE could inhibit HCT116 cell proliferation and induce cell cycle arrest and apoptosis. Decreased β-catenin protein expression may mediate the anti-proliferative effects of CAPE.     

Mechanisms underlying aspirin-mediated growth inhibition and apoptosis induction of cyclooxygenase-2 negative colon cancer cell line SW480

AIM： To investigate the effects of aspirin （acetylsalicylic acid） on proliferation and apoptosis of colorectal cancer cell line SW480 and its mechanism. METHODS： Cyclooxygenase （COX）-2 negative colorectal cancer cell line SW480 was treated with aspirin at concentrations of 2.5 mmol/L, 5.0 mmol/L, 10.0 mmol/L for different periods in v/tro. Anti-proliferation effect of aspirin on SW480 was detected by 3-（4,5-dimeth- ylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. Cell cycle and apoptosis were observed by flow cytometry （FCM）. Transmission electron microscope （TEM） was used for morphological study. Apoptosis-associated genes were detected by immunohistochemical staining and Western blotting. RESULTS： Aspirin inhibited SW480 proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment with different concentrations of aspirin significantly increased the proportions of cells at the G0/G1 phase and decreased the proportions of cells at the S- and G2/M phases in a concentration-dependent manner. Aspirin not only induced apoptosis but also caused cell necrosis at a high concentration as well. After treatment with aspirin, SW480 cells displayed typically morphological features of apoptosis and necrosis under TEM, and increased the Bcl-2 expression in cells, but the expression of Bax was down regulated. CONCLUSION： Aspirin inhibits proliferation and induces apoptosis of SW480 cells. Its anti-tumor mechanism may arrest cell cycle and shift Bax/Bcl-2 balance in cells.     

ShRNA-mediated gene silencing of β-catenin inhibits growth of human colon cancer cells

AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205.METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry.RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level.The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing.CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.     

雌激素受体β过表达对大肠癌细胞增殖凋亡的影响

目的观察雌激素受体β（ERβ）过表达对大肠癌细胞增殖和凋亡的影响,并探讨其机制。方法以脂质体介导的ERβ基因转染SW480细胞,G418筛选阳性克隆（SW480-C1-ERβ）。RT—PCR及WesternBlot鉴定ERβ的过表达。以正常SW480细胞和转染了空质粒的SW480细胞（SW480-pEGFP—C1）作为对照,在无雌激素或有雌激素作用的条件下,采用MTT法检测细胞增殖,流式细胞术检测细胞凋亡率,实时荧光定量RT—PCR方法检测凋亡相关基因survivin和Bax表达。结果SW480和SW480-pEGFP—C1细胞中ERβ mRNA和蛋白表达较低,而稳定转染的SW480-C1-ERβ细胞中ERβmRNA和蛋白表达明显增加。在有或无雌激素作用的条件下均可发现,与SW480细胞或SW480-pEGFP—C1细胞比较,SW480-C1-ERβ细胞增殖速度减慢,凋亡率明显增高,survivin表达减低,Bax表达增高;在SW480-C1-ERβ细胞中,有雌激素作用者较无雌激素作用者以上变化更明显。结论ERβ过表达可以同时以配体非依赖性和配体依赖性的方式抑制细胞增殖和增加细胞凋亡,可能与调控凋亡相关基因survivin和Bax表达有关。     

Synergistic antitumor effect of TRAIL and doxorubicin on colon cancer cell line SW480

AIM: TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) has been reported to specifically induce apoptosis of cancer cells although only a small percentage of cell lines were sensitive to it. Cell lines not responding to TRAIL in vitro were said to be more prone to apoptosis when TRAIL was combined with another anticancer agent.Generally, factors affecting drug-sensitivity involve many apoptosis-related proteins, including p53. The expression of wild-type p53 gene was proposed as an important premise for tumor cells responding to chemotherapy. The present study was to investigate the cell killing action of TRAIL on colon cancer cell line SW480, its synergistic effect with doxorubicin, and the possible mechanisms.METHODS: SW480 cells were cultured in the regular condition and incubated with different levels of agents.Morphologic changes in these cells after treatment were observed under phase-contrast microscope and cytotoxicity by TRAIL alone and in combination with doxorubicin was quantified by a 1-day microculture tetrazolium dye (MTT) assay. In addition, flow cytometry assay (FCM) and transmission electron microscopy were used to detect apoptosis among these cells. Variation of p53 protein level among different groups according to concentrations of agents was measured by Western blot assay.RESULTS: (1) SW480 cells were not sensitive to TRAIL,with IC50>l mg·L^1 and dose-independent cytotoxicity. (2)SW480 cells were sensitive to doxorubicin at a certain degree,with dose-dependent cytotoxicity and IC50=65.25±3.48μmol·L^-1. (3) TRAIL could synergize with doxorubicin to kill SW480 cells effectively, which was represented by the boosted killing effect of doxorubicin on theses cells. IC50 of doxorubicin against SW480 cells sharply reduced when it was combined with TRAIL. (4) Subtoxic TRAIL (100 μg·L^-1),combined with subtoxic doxorubicin (0.86 μmol·L^-1), could kill SW480 cells sufficiently. Cytotoxicity by MTT assay arrived at 80.12±2.67 %, which was significantly higher than that by TRAIL or doxorubicin alone, with P=0.006 and 0.003 respectively. This killing effect was partly due to apoptosis. It was proved by large amounts of apoptotic cells under phase-contrast microscopy, cell apoptosis rate of 76.82±1.93 % by FCM assay and typical apoptotic morphology observed through transmission electron microscopy. Increase of apoptosis after combined treatment had no relation with protein level of p53 (p>0.05).CONCLUSION: SW480 cells are not sensitive to TRAIL, but TRAIL can synergize with lower concentra~on of doxorubidn to induce apoptosis effectively. The status of p53 protein is not involved in the mechanism of synergistic apoptosis. It suggests the potential therapeutic applicability of the combination of TRAIL with doxorubidn against colon cancers.     

Synergistic antitumor effect of TRATL and doxorubicin on colon cancer cell line SW480

AIM: TRAIL (tumor necrosis factor-related apoptosisinducing ligand) has been reported to specifically induce apoptosis of cancer cells although only a small percentage of cell lines were sensitive to it. Cell lines not responding to TRAIL in vitro were said to be more prone to apoptosis when TRAIL was combined with another anticancer agent.Generally, factors affecting drug-sensitivity involve many apoptosis-related proteins, including p53. The expression of wild-type p53 gene was proposed as an important premise for tumor cells responding to chemotherapy. The present study was to investigate the cell killing action of TRAIL on colon cancer cell line SW480, its synergistic effect with doxorubicin, and the possible mechanisms. METHODS: SW480 cells were cultured in the regular condition and incubated with different levels of agents.Morphologic changes in these cells after treatment were observed under phase-contrast microscope and cytotoxicity by TRAIL alone and in combination with doxorubicin was quantified by a 1-day microculture tetrazolium dye (MTT)assay. In addition, flow cytometry assay (FCM) and transmission electron microscopy were used to detectapoptosis among these cells. Variation of p53 protein level among different groups according to concentrations of agents was measured by Western blot assay.RESULTS: (1) SW480 cells were not sensitive to TRAIL,with IC50＞1 mg@L1 and dose-independent cytotoxicity. (2)SW480 cells were sensitive to doxorubicin at a certain degree,with dose-dependent cytotoxicity and IC50=65.25+3.48μmol@L-1. (3) TRAIL could synergize with doxorubicin to kill SW480 cells effectively, which was represented by the boosted killing effect of doxorubicin on theses cells. IC50 of doxorubicin against SW480 cells sharply reduced when it was combined with TRAIL. (4) Subtoxic TRAIL (100 μg.L-1),combined with subtoxic doxorubicin (0.86 μmol@L1), could kill SW480 cells sufficiently. Cytotoxicity by MTT assay arrived at 80.12+2.67%, which was significantly higher than that by TRAIL or doxorubicin alone, with P=0.006 and 0.003 respectively. This killing effect was partly due to apoptosis. It was proved by large amounts of apoptotic cells under phase-contrast microscopy, cell apoptosis rate of 76.82±1.93 % by FCM assay and typical apoptotic morphology observed through transmission electron microscopy. Increase of apoptosis after combined treatment had no relation with protein level of p53 (P＞0.05). CONCLUSION: SW480 cells are not sensitive to TRAIL, but TRAIL can synergize with lower concentration of doxorubicin to induce apoptosis effectively. The status of p53 protein i snot involved in the mechanism of synergistic apoptosis. It suggests the potential therapeutic applicability of the combination of TRAIL with doxorubicin against colon cancers.