Anti-cancer effect of ethylacetate fraction from Orostachys japonicus on HT-29 human colon cancer cells by induction of apoptosis through caspase-dependent signaling pathway

Objective: To investigate the anti-colon cancer effects of ethylacetate fraction from Orostachys japonicus(0. japonicus) on HT-29 cancer cells. Methods: The viability of HT-29 cells was assayed by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium(MTS) method. Apoptosis induction and cell cycle inhibition were confirmed by fluorescein isothiocyanate and propidium iodide staining using flow cytometry.Morphological changes in the nucleus were observed, using a fluorescence microscope with4',6-diamidino-2-phenylindole(DAPI) nuclear staining. The expression levels of the upstream and downstream proteins involved in the anti-cancer mechanism were confirmed by Western blotting. Results: After treating HT-29 cells with different concentrations of ethylacetate fraction from O. japonicus, the viability of cells decreased in a concentration-dependent manner,while apoptosis induction and apoptotic body formation increased. Cell cycle analysis showed that the arrest occurred at the sub-G_1 and S phase. Among the upstream and downstream proteins involved in anti-cancer activity, the level of B cell lymphoma-2 decreased, and the bcl-2-associated x protein increased. The level of pro-caspase-3, pro-caspase-8, and pro-caspase-9 decreased, while the level of cleaved-caspase-3, cleaved-caspase-8, and cleaved-caspase-9 increased. Moreover, the phosphorylation, that is, activation of extracellular signal regulated kinase 1/2, Jun-N-terminal kinase, and p38 increased. Conclusions: Combining the above results, it is thought that the survival of HT-29 cells is suppressed by ethylacetate fraction from0. japonicus through mitochondrial regulation-induced caspase cascade activation, induction of apoptosis and cell cycle arrest.

Epigenetic modification regulates both expression of tumor-associated genes and cell cycle progressing in human colon cancer cell lines: Colo-320 and SW1116

The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.

Leucine-rich repeat-containing G protein-coupled receptor 5 marks different cancer stem cell compartments in human Caco-2 and LoVo colon cancer lines

BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.

姜黄素类似物对人结肠癌HT-29细胞增殖与自噬的影响

目的初步探究姜黄素类似物——WH-8对人结肠癌HT-29细胞增殖和自噬的影响。方法选用不同浓度WH-8作用于人结肠癌HT-29细胞,应用四甲基偶氮唑盐还原法观察药物对细胞的生长抑制作用;通过荧光染色技术和细胞成像技术观察WH-8作用下细胞自噬囊泡的变化;四甲基偶氮唑盐还原法检测经自噬特异性抑制剂3-MA预处理后WH-8对细胞生长抑制率的影响;蛋白质印迹法观察WH-8作用下细胞自噬特征性蛋白酵母自噬相关基因1(Beclin 1)和微管相关蛋白1轻链3(LC3)的表达情况。结果WH-8呈时间-剂量依赖性抑制人结肠癌HT-29细胞增殖,48 h平均半数抑制浓度为(12.5±1.3)μmol/L;一定浓度下WH-8可诱导细胞的自噬囊泡增多;3-MA可逆转WH-8对人结肠癌HT-29细胞的生长抑制作用,差异有统计学意义(P<0.05);WH-8可诱导Beclin-1表达上调,且在一定时间内促进LC3Ⅰ向LC3Ⅱ转化。结论WH-8可抑制人结肠癌HT-29细胞增殖并诱导细胞自噬。

基于JAK2/STAT3信号通路探讨对叶百部总生物碱对人结肠癌HT-29细胞增殖、凋亡的影响

目的基于Janus激酶2(JAK2)/信号转导及转录激活因子3(STAT3)信号通路,探讨对叶百部总生物碱对人结肠癌HT-29细胞增殖、凋亡的影响。方法将人结肠癌HT-29细胞分为55μg/mL组、150μg/mL组和250μg/mL组进行实验,另设仅添加培养基的空白组(含细胞)。除空白组外,其他组给予相应浓度的对叶百部总生物碱进行干预。干预24 h、48 h、72 h后,采用四甲基偶氮唑蓝法检测各组细胞增殖抑制率;干预48 h后,采用Hoechst 33258染色法观察各组细胞凋亡情况,采用流式细胞术检测各组细胞凋亡率,采用Western blot检测各组细胞JAK2、磷酸化JAK2(p-JAK2)、STAT3和磷酸化STAT3(p-STAT3)的蛋白表达水平。结果与空白组比较,各浓度组细胞增殖抑制率增加;经Hoechst 33258染色后在各浓度组中可观察到典型的细胞凋亡形态改变,凋亡细胞数及细胞凋亡率均增加(均P<0.05);流式细胞术检测结果显示150μg/mL组和250μg/mL组细胞凋亡率增加(均P<0.05)。与空白组比较,各浓度组的p-JAK2蛋白和p-STAT3蛋白表达水平均下调(均P<0.05)。55μg/mL组、150μg/mL组和250μg/mL组的细胞增殖抑制率、凋亡细胞数及细胞凋亡率依次增加,p-JAK2蛋白和p-STAT3蛋白表达水平依次降低(均P<0.05)。结论对叶百部总生物碱可能通过抑制JAK2/STAT3信号通路相关蛋白的活化,来抑制人结肠癌HT-29细胞增殖并促进其凋亡。

Influence of paeonol on expression of COX-2 and p27 in HT-29 cells

AIM： To investigate the effect of paeonol on controlling the proliferation of colorectal cancer cell line HT-29 and to discuss its possible mechanism. METHODS： The inhibitory effect of paeonol on proliferation of HT-29 cells was detected by M-I-I- assay. The results of apoptosis were measured by flow cytometry. Immunocytochemical staining was performed to detect the expression of cyclooxygenase-2 （COX-2） and protein p27 in HT-29 cells treated with paeonol at different concentrations. Reverse transcription-polymerase chain reaction （RT- PCR） was used for mRNA analysis. RESULTS： From the data of both MTT and flow cytometry, we observed that cell proliferation was inhibited by different concentrations of paeonol. By immunocytochemical staining, we found that HT-29 cells treated with paeonol （0.024-1.504 mmol/L） reflected reduced expression of COX-2 and increased expression of p27 in a dose-dependent manner. RT-PCR showed that paeonol down-regulated COX-2 and up-regulated p27 in a dose- and time-dependent manner in HT-29 cells. CONCLUSION： One of the apoptotic mechanisms of paeonol is down-regulation of COX-2. p27 is upregulated simultaneously and plays an important part in controlling cell proliferation and is a crucial factor in the Fas/FasL apoptosis pathway.

Growth hormone releasing peptide 2 reverses anorexia associated with chemotherapy with 5-fluoruracil in colon cancer cell-bearing mice

The cancer-associated anorexia-cachexia syndrome is observed in 80% of patients with advanced-stage cancer, and is one of the major obstacles in chemo- therapy. Ghrelin is a orexigenic hormone that has been proposed to prevent anorexia. Aim of the study was to determine whether the addition of the ghrelin agonist growth hormone releasing peptide 2 (GHRP-2) to cytotoxic therapy with 5-fluoruracil (5-FU) prevents the anorexia associated with chemotherapy in cancer cachectic mice. Thirty-three BALB/c female tumourbearing mice were randomized to receive a solution containing: (a) placebo; (b) GHRP-2; (c) 5-FU; or (d) 5-FU + GHRP-2. Ten BALB/c no tumour-bearing mice received placebo solution. Food intake and survival were checked. Six hours after the drug injection the cumulative food intake was signifi cantly increased in mice treated with the combination of 5-FU + GHRP-2 versus the 5-FU alone (P = 0.0096). On day 3, the cumulative food intake of mice treated with GHRP-2,5-FU and 5-FU + GHRP-2 signifi cantly increased com- pared with naive and vehicle groups (P = 0.0007, P = 0.0038 and P = 0.0166, respectively). The median survival time was longer in 5-FU + GHRP-2 treated mice than in those with 5-FU, although it was not signifi cant (18 d versus 15.5 d, P = 0.7). For the fi rst time, we demonstrated that the addition of GHRP-2 to cytotoxic therapy with 5-FU improved appetite in tumour-bearing mice with anorexia/cachexia syndrome in early stage. These data suggest that GHRP-2 may improve the effi cacy of therapy and the quality of life of cancer patients thank to the amelioration of their nutritional state.

Molecular analysis and anticancer properties of two identified isolates,Fusarium solani and Emericella nidulans isolated from Wady El-Natron soil in Egypt against Caco-2(ATCC) cell line

Objective:To characterize,identify and investigate the anticancer properties of two new soil fungal isolates,Emericella nidulansand Fusarium solani isolated from Wady El-Natron in Egypt against colon cancer Caco-2(ATCCj cell line.Methods:Soil sample was cultured and two strains were chosen for morphological and phenotypical characterization.Partial sequences of the 18s rRNA gene and the internal transcribed spacer region ITS of the two isolates were amplified by PCR.Phylogenetic tree construction and analysis of the resulted multiple sequences from the two fugal isolates were also carried out.In vitro anticancer activity of the two strains was done against colon Caco-2 cancer cell line.Reverse transcription — PCR was carried out to detect level of expression of p53 in Caco-2 cell line.Results:HF.I displayed morphological and genotypic characteristics most similar to that of Fusarium solani while HF.2 was most similar to Emericella nidulans with high similarity of 99%and 97%respectively.The multiple sequence alignment of the two fungal isolates showed that,the maximum identical conserved domains in the 18s rRNA genes were identified with the nucleotide regions of Slst to 399th base pairs,88th to 525th base pairs respectively.While those in the ITS genes were identified with the nucleotide regions of 88th to 463rd and Slst to 274th.The two isolates showed IC<sub>50 value with（6.24±5.21） and（9.84±0.36） μ g/mL) concentrations respectively at 28h.Reverse transcription- PCR indicated that these cells showed high level of expression for p53 mRNA.Conclusions:The morphology and molecular analysis identified HF.1 and HF.2 to be Fusarium solani and Emericella nidulans;new isolates of anticancer producing fungi from Wady El-Natroon city in Egypt.Treatment with the two isolates caused P53 expression in Caco-2 cell line.These two isolates can be used as an anticancer agents.

Oxidative stress-induced mitochondrial dysfunction in a normal colon epithelial cell line

AIM To determine how a normal human colon cell line reacts to microbial challenge as a way to study oxidative stress-induced responses associated with inflammatory bowel disease.METHODS Normal human colon epithelial cells(ATCC?CRL.1790?)were stimulated with either heat killed E.coli or heat killed murine cecal contents(HKC)and examined for several relevant biomarkers associated with inflammation and oxidative stress including cytokine production,mitochondrial autophagy and oxidant status.TNFα,IL-1βand IL-8 protein concentrations were measured within the supernatants.Fluorescent microscopy was performed to quantify the production of reactive oxygen species(ROS)using an oxidation responsive fluorogenic probe.Mitochondrial morphology and mitochondrial membrane potential was assessed by dual staining using COXIV antibody and a dye concentrating in active mitochondria.Mitochondrial ROS scavenger was used to determine the source of ROS in stimulated cells.Autophagy was detected by staining for the presence of autophagic vesicles.Positive controls for autophagy and ROS/RNS experiments were treated with rapamycin and chloroquine.Mitochondrial morphology,ROS production and autophagy microscopy experiments were analyzed using a custom acquisition and analysis microscopy software(Image J).RESULTS Exposing CRL.1790 cells to microbial challenge stimulated cells to produce several relevant biomarkers associated with inflammation and oxidative stress.Heat killed cecal contents treatment induced a 10-12fold increase in IL-8 production by CRL.1790 cells compared to unstimulated controls at 6 and 12 h(P<0.001).Heat killed E.coli stimulation resulted in a4-5 fold increase in IL-8 compared to the unstimulated control cells at each time point(P<0.001).Both heat killed E.coli and HKC stimulated robust ROS production at 6(P<0.001),and 12 h(P<0.01).Mitochondrial morphologic abnormalities were detected at 6 and12 h based on reduced mitochondrial circularity and decreased mitochondrial membrane potential,P<0.01.Microbial stimulation also induced significant autophagy at 6 and 12 h,P<0.01.Lastly,blocking mitochondrial ROS generation using mitochondrial specific ROS scavenger reversed microbial challenge induced mitochondrial morphologic abnormalities and autophagy.CONCLUSION The findings from this study suggest that CRL.1790cells may be a useful alternative to other colon cancer cell lines in studying the mechanisms of oxidative stress events associated with intestinal inflammatory disorders.

Fermented Herbal Decoction Selectively Targeting Human Cancer Cell Line and Human Pathogenic Microorganism

Introduction: Prolonged immuno-suppressed status promised to induce internal growth of malignant cell and infectious agent, yet, only a small part of affected individuals seek medical attention or berried by commercially over-flowed fake information. Several studies have described complementary and alternative medicine as effective strategies for improving anti-infectious agent including malignant cell. The purpose of this study was to investigate the effect of a fermented herbal decoction (FHD) both in vitro and in vivo to malignant cells and microorganism by regulating leukocyte subset proportioning FHD as dietary material. Methods: In this approach of alternative study, selective anti-cancer effect by fermented decoction was tried to show first in vitro system both, cancer cell and virus strain. The fermented herbal decoction consisting of 80 sorts of herbs and fruits. The selective toxicity was set up and then for immunological factors in animal and human. The most important factor is to reduce side effect for a normal cell. Results: First, FHD was proved as safe by animal test. FHD regulated also the proportion of granulocyte and lymphocyte ratio both animal and human. In vitro culture showed selective toxicity by FHD against human melanoma and leukemia cell line but reduced toxicity was showed by normal cell line. As for the anti-virus activity, anti-virus effect was tested on the feeder layer of human fibroblast cell, after 9 days of culture. Second, FHD inhibits colon cancer growth in 3-methylholanthrene induced cancer in rat. Conclusion: The present results suggest that our fermented herbal decoction showed selective anti-cancer activities and anti-virus activities, together with the regulative effect on the immune system.

苦参碱抑制大肠癌HT-29细胞环氧化酶-2表达的研究

目的从基因和蛋白水平探讨中药成分苦参碱 (matrine)对大肠癌HT-2 9细胞环氧化酶-2(COX-2 )表达的影响。方法分别采用RT-PCR、Western blot、ELISA等方法检测不同浓度苦参碱处理HT-2 9细胞前后COX-2mRNA、蛋白及其产物前列腺素E2 (PGE2 )水平的改变。结果苦参碱可抑制HT-2 9细胞COX-2mRNA、蛋白表达及PGE2 合成水平 ,但对COX 1无影响。当苦参碱 2 .0mg/ml处理时 ,COX 2mRNA表达在处理后 6h和 9h时抑制率均为 10 0 % ;细胞培养液PGE2 合成水平在 9h时抑制率为6 3.9% ;COX-2蛋白表达在 12h和 2 4h时抑制率分别为 4 8%和 10 0 %。结论苦参碱具有选择抑制HT-2 9细胞COX-2的基因转录、蛋白表达和功能活性等作用 ,在一定浓度和时间范围内 。

戊地昔布对人结肠癌HT-29细胞凋亡的影响

目的观察戊地昔布(Valdecoxib)对COX-2高表达的人结肠癌HT-29细胞凋亡的影响。方法将体外培养HT-29细胞分为正常组(C)、药物处理组(V)及溶剂对照组(S)。采用流式细胞术检测细胞凋亡,Western blot检测COX-2、caspase-3、cleaved caspase-3、Bcl-2、p38 MAPK、p-p38MAPK。结果与正常组相比,药物处理组细胞凋亡明显增加(P<0.05),cleaved caspase-3和p-p38MAPK表达增高,Bax/Bcl-2比率明显升高(P<0.05)。Valdecoxib干预能够显著促进HT-29细胞凋亡,上调cleaved caspase-3和p-p38 MAPK的表达,增加Bax/Bcl-2比率。结论 COX-2选择性抑制剂Valdecoxib能够促进HT-29细胞凋亡部分可能是通过激活p38MAPK信号通路而实现的。

人参皂苷Rg3对HT-29细胞株MMP-1表达和迁移能力的影响

目的:研究人参皂苷Rg3对结肠癌细胞株HT-29基质金属蛋白酶-1(MMP-1)表达和细胞迁移能力的影响。方法:体外培养HT-29细胞,分为人参皂苷Rg3高剂量组(100μg/mL)、中剂量组(50μg/mL)、低剂量组(25μg/mL)和空白对照组,培养HT-29细胞24、48、72h,RT-PCR法测MMP-1 mRNA表达。利用划痕实验观察Rg3对HT-29细胞迁移能力的影响。结果:24h高剂量组与对照组相比,有显著的统计学差异(P<0.01);48h低、中、高剂量组与对照组相比均有显著的统计学差异(P<0.05、P<0.01、P<0.01);72h低、中、高剂量组与对照组相比均有显著的统计学差异(P<0.01、P<0.01、P<0.01)。划痕实验中空白对照组过河时间为(47.33±2.49)h,低、中、高剂量组过河时间分别为(55.33±2.49)h(P<0.01)、(64.00±1.63)h(P<0.01)和(73.33±1.89)h(P<0.01)。结论:人参皂苷Rg3能抑制HT-29细胞MMP-1的表达和抑制HT-29细胞的迁移能力,并且随着药物浓度的增加及时间的延长,抑制作用增强。

二烯丙基二硫对人结肠癌HT-29细胞G_1期的阻滞作用

目的探讨二烯丙基二硫(DADS)对人结肠癌HT-29细胞G1期的阻滞作用及分子机制。方法采用MTT、细胞计数法、流式细胞术和免疫细胞化学方法分析DADS对体外培养的HT-29细胞增殖抑制作用、细胞周期分布及细胞周期相关蛋白表达的影响。结果MTT法显示,60、120μmol.L-1DADS作用HT-29细胞24 h后,生长抑制率分别达23.1%、45.6%。细胞计数法表明,常规培养HT-29细胞群体倍增时间为22.58 h,60μmol.L-1DADS作用HT-29细胞后,其细胞群体倍增时间延长到31.20 h。流式细胞仪分析结果显示,60μmol.L-1DADS阻滞HT-29细胞在G1期,与对照组相比,可使G1期细胞增加约2倍,而120μmol.L-1DADS显著地将细胞阻滞在G2/M期。免疫细胞化学分析表明在G1期阻滞同时有p21W af1蛋白表达上调,Cyc lin E、C-myc蛋白表达下降。结论低剂量DADS对HT-29细胞的抑制增殖作用可能与G1期阻滞有关,DADS对HT-29细胞G1期阻滞的分子机制可能与调节p21W af1、Cyc lin E、C-myc表达相关。

肌醇六磷酸对人结肠细胞系HT-29细胞周期的影响

目的:研究肌醇六磷酸(IP6)对HT-29细胞周期的影响并探讨其作用机制。方法:应用四甲基偶氮唑蓝实验(MTT法)观察IP6对HT-29细胞增殖的影响;流式细胞仪检测不同浓度IP6作用72h对HT-29细胞周期的影响;应用免疫细胞化学法检测IP6对HT-29细胞内突变型p53、细胞周期抑制蛋白p21表达的影响。结果:IP6对结肠癌细胞株的生长具有抑制作用,且具有浓度依赖和时间依赖关系。经IP6作用处理的HT-29细胞的细胞周期发生G1期阻滞。与对照组比,各IP6浓度组均能抑制突变型p53蛋白的表达(P<0.05),上调p21蛋白的表达(P<0.05)。结论:IP6对HT-29细胞的生长具有明显的抑制作用。其机制可能是IP6降低p53蛋白的异常表达,刺激p21蛋白的表达,使细胞周期发生G1期阻滞,从而起到抑制细胞增殖的作用。

pcDNA3.1/DLC-1重组质粒的构建及其在HT-29细胞中的表达

目的构建和表达DLC-1(deleted in liver cancer)基因重组质粒。方法用PCR法得到DLC-1基因片段,此基因片段带有XbaⅠ和BamHⅠ两个酶切位点,然后将此片段和真核表达载体pcDNA3.1连接,转化大肠杆菌DH5a,利用脂质体介导将pcDNA3.1/DLC-1重组质粒转染到结肠癌HT-29细胞中,再用RT-PCR法检测重组质粒的表达。结果重组质粒经XbaⅠ和BamHⅠ双酶切和测序与DLC-1基因序列一致;利用脂质体介导将pcDNA3.1/DLC-1重组质粒导入HT-29细胞,获得了DLC-1基因的表达。结论成功构建pcDNA3.1/DLC-1重组质粒并在HT-29细胞内表达。

人结直肠癌耐药细胞株HT-29/CPT-11的构建及其生物学特性探讨

目的:建立耐伊立替康(CPT-11)的人结直肠癌细胞株(HT-29/CPT-11),并研究其生物学特性。方法:采用药物浓度梯度递增间歇诱导法建立人结直肠癌耐药株HT-29/CPT-11;CCK-8法检测CPT-11对亲本细胞HT-29和耐药细胞株HT-29/CPT-11细胞的半数抑制率(IC50);绘制细胞生长曲线,并计算细胞倍增时间;流式细胞术分析细胞周期分布;RT-PCR检测HT-29/CPT-11和HT-29细胞MDR-1 mRNA的表达。结果:(1)成功建立人结直肠癌耐药细胞株HT-29/CPT-11,耐药指数为6.51。(2)HT-29/CPT-11耐药细胞株倍增时间较原代细胞HT-29延长[分别为(41.29±1.69)h和(27.12±2.73)h,P<0.05]。(3)流式细胞术检测细胞周期结果显示,耐药细胞株HT-29/CPT-11 G1期细胞数目增加,S期细胞数目减少(P<0.05)。(4)耐药细胞HT-29/CPT-11的MDR-1 mRNA表达水平明显高于亲本细胞株HT-29,分别为1.086±0.054和0.416±0.02(P<0.05)。结论:成功构建了人结直肠癌耐药细胞株HT-29/CPT-11,为下一步研究耐药机制奠定实验基础。

扶正解毒祛瘀方联合奥沙利铂对人结肠癌HT-29细胞增殖与凋亡的影响及机制研究

目的:研究扶正解毒祛瘀方(简称"扶正方")联合奥沙利铂(L-OHP)对人结肠癌HT-29细胞增殖与凋亡的影响及机制。方法:将HT-29细胞分为空白对照组(不加药物)、扶正方组(1 000 mg/L)、L-OHP组(31.25 mg/L)和联合用药组(1 000 mg/L扶正方+31.25 mg/L L-OHP)。加入相应药物作用48 h后,采用MTT法检测细胞增殖情况,倒置显微镜下观察细胞形态的改变,流式细胞术检测细胞周期和凋亡率,实时荧光定量聚合酶链式反应(q RT-PCR)法检测细胞中促凋亡基因Bax、抑凋亡基因Bcl-2 m RNA的表达,Western blot法检测细胞中Bax、Bcl-2蛋白的表达。结果:与空白对照组比较,L-OHP组和联合用药组细胞增殖均受到抑制、S期和G_2/M期细胞比例升高、G_0/G_1期细胞比例降低(P<0.05),L-OHP组、扶正方组和联合用药组细胞凋亡率升高、细胞中Bax m RNA及蛋白的表达上调、细胞中Bcl-2 m RNA的表达下调(P<0.05),且联合用组变化较两药单用组更明显(P<0.05)。结论:扶正方与L-OHP联合应用可抑制HT-29细胞的增殖、促进细胞凋亡,且作用优于两药单用;其机制可能与上调细胞中Bax基因与蛋白表达、下调细胞中Bcl-2基因表达有关。

分化抑制因子1对结肠癌HT-29细胞增殖的影响

目的检测分化抑制因子1(Id1)对结肠癌HT-29细胞VEGF表达的影响,探讨其在结肠癌增殖中的作用。方法 HT-29转染Id1表达质粒,RT-PCR方法和Western印迹法检测血管内皮生长因子(VEGF)mRNA和蛋白的表达,MTT法检测各组细胞增殖情况;合成Id-1干扰序列转染HT-29细胞后,RT-PCR及Western印迹检测HT-29细胞VEGF mRNA和蛋白的表达情况,采用MTT法检测各组细胞增殖情况。结果 Id1表达质粒空白组、对照组(空载体组)、过表达组VEGF/GAPDH mRNA分别为:0.002 99±0.000 687、0.003 49±0.001 34、0.031 3±0.006 05(P<0.01);VEGF/GAPDH蛋白分别为:0.132±0.035 1、0.131±0.053 0、0.245±0.032 6(P<0.01),MTT实验显示相对对照组,过表达组增殖明显快(P<0.01)。Id-1干扰空白组、对照组(空载体组)、抑表达组VEGF/GAPDH mRNA分别为:0.006 16±0.000 829、0.006 26±0.000 447、0.002 3±0.000 308(P<0.01);VEGF/GAPDH蛋白分别为:0.450±0.039 3、0.464±0.023 1、0.231±0.027 3(P<0.01)。MTT实验显示相对对照组,抑表达组增殖明显减慢(P<0.01)。Id1过表达能显著上调VEGF mRNA和蛋白表达,提高细胞的生长,Id1抑制后能显著下调VEGF mRNA和蛋白表达,减缓细胞的生长。结论在结肠癌HT-29细胞中Id1为VEGF的上游基因,Id1通过Id1↑→VEGF↑途径来影响结肠癌细胞增殖,在肿瘤血管生成中发挥重要作用。Id1有望成为结肠癌治疗的一个新靶点。

JR6对人结肠癌细胞HT-29氧化还原系统影响

探讨新型抗肿瘤药物JR6诱导人结肠癌细胞HT-29凋亡机制.使用噻唑兰比色法(MTT)检测JR6对人结肠癌细胞HT-29的生长抑制作用,并测定HT-29细胞中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)的活性和丙二醛(MDA)浓度.JR6对HT-29细胞生长有明显抑制作用,可以降低HT-29细胞中SOD、GSH-Px、CAT活性,升高MDA浓度.JR6对HT-29细胞有明显的细胞毒作用,其IC50为39.8μg/mL,可能通过影响HT-29细胞中SOD、GSH-Px、CAT活性和MDA浓度,达到诱导HT-29细胞凋亡的目的.