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OBJECTIVE： To conduct structural modification of tectorigenin to search for new compounds with anti-tumor activity. METHODS： Tectorigenin was used as a lead compound， and then added into amine reagents as ethanolamine， methylamine， ethylamine， dimethylamine， diethylamine， n-propylamine and formaldehyde solution. Tectorigenin Mannich base derivatives were synthesized by mannich reaction with as the lead compound. The structures of the derivatives were identified according to IR， UV， MS and NMR data. Solubility of tectorigenin and its derivatives were investigated by solubility test method. MTT assay was used to investigate the inhibitory effects of tectorigenin and its derivatives on the proliferation of human colon cancer cell line HCT116， human lung cancer cell line A549 and human hepatoma cell line HepG2， and half inhibitory concentration （IC50） was calculated. The inhibition rate of tectorigenin and its derivatives （100 mg/kg） on H22 hepatoma-bearing mice in vivo was studied. RESULTS： Totally of 6 kinds of tectorigenin mannich base derivatives were synthesized， such as 8-（N-hydroxyethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-methyl）-methyleneamino-5，7，4′-trihydroxy-6- methoxyisoflavone， 8-（N， N-diethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N， N-dimethyl）-methyleneamino- 5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-ethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-propyl）- methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone （compounds 1-6 in turn）. Compared with tectorigenin， the water solubility of six derivatives was significantly improved， and the solubility was 5-20 times higher than that of tectorigenin. IC50 of compounds 1， 3 and 5 to HCT116 cells were （34.82±3.27）， （16.21±4.13）， （33.12±3.25） μmol/L， which were stronger than that of tectorigenin [（45.23±5.74） μmol/L]； IC50 of compounds 1， 3 and 5 to A549 cells were （37.05±5.74）， （26.88±4.52）， （30.13±6.23） μmol/L， which were stronger than that of tectorigenin [（53.24±6.34） μmol/L]； IC50 of compounds 1， 3 and 5 to HepG2 cells were （23.74±1.45）， （18.96±2.34）， （30.95±2.87） μmol/L， which were stronger than that of tectorigenin [（48.98±2.58） μmol/L]. Compounds 1， 3 and 5 showed higher inhibition rates （55.51％， 57.20％ and 49.15％） than tectorigenin （33.05％） on H22 hepatoma-bearing mice， respectively. The other three compounds had no obvious advantage over tectorigenin in anti-tumor activity. CONCLUSIONS： In this study， compounds 1， 3 and 5 of six tectorigenin mannich base derivatives synthesized in this study have stronger antitumor activity than tectorigenin.
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Objective To establish chicken embryo transplantation model of human colon cancer and to research the effect of so‐lanine on angiogenesis .Methods Cases with chicken embryos were divided into the low‐,mid‐and high dose solanine group and con‐trol group ,with 10 cases in each groups ,and then the cultured human colon cancer cell line HT‐29 cell lines were inoculated to the chicken embryo villus allantois membrane (CAM ) .We observed the characteristics of the transplanted tumor in CAM angiogenesis by the stereo microscope .Image analysis software of Image‐pro plus 6 .0 and immunohistochemical method were used to observe the effect of different dose of solanine on angiogenesis .Results HT‐29 cell lines were inoculated to CAM 3-5 days ,a large number of blood vessels concentrated in tumors ,growing into or acrossing the surface of tumors .While tumors also rapidly growed .We took photo on the 5th day after receiving medicine and did imaging analysis .Then we calculated the area of angiogenesis in experimental group ,which was significantly lower than that of the control group ,quantitatively in a dose‐dependent manner .There were signifi‐cant differences among the groups(P<0 .01) .Microvascular density of 3 different dose of solanine was significantly lower than that of the control group by immunohistochemical method ;the expression of Ki‐67 antigen index decreased gradually ,which was highest in the control group ,and there were significant differences among the groups (P<0 .01) .Conclusion Solanine could inhibit angio‐genesis induced by human colon cancer HT‐29 cell lines obviously ,thus inhibiting the growth of tumor and providing an important basis for the treatment of anti‐tumor angiogenesis .
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Objective To investigate the inhibition mechanism of sodium selenite on HCT116 cells.Methods In the present study,we explored the cytotoxicity induced by sodium selenite and the underlying mechanism by MTS assay,WesternBlot,and small RNA interference technique.Results It was found that the sodium selenite at 5uM concentration could indeed reduce the viability of colon cancer cell line HCT116 by a large margin through increasing the generation of reactive oxygen species (ROS),and that the increased levels of ROS could activate c-Jun Nh2-terninal kinase 1 (JNK1).Additionally,knockdown expression of JNK1 or p53 by using RNAi attenuated the cytotoxicity induced by sodium selenite,indicating that both of JNK1 and p53 are required in the process of cell death induced by sodium selenite.Conclusion The sodium selenite could induces cell death in HCT116 through oxidative stress by involvement of JNK1 and p53,both of which play a critical role in toxicity of sodium selenite.
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To investigate the inhibitive effect of the co-culture supernatant of Toxoplasma gondii on the proliferation of human colon cancer cell line sw480 and/or its induced apoptosis and necrosis in vitro,the co-culture model of sw480 cells (1x10~6) was established with different number of Toxoplasma gondii (the concentration of tachyzoites was 2×10~6,4×10~6,8×10~6,16×10~6 respectively),and the co-culture supernatants were gathered 72 hours later.The sw480 cells were treated for different hours with different models of the co-culture supernatant.The parasitism and proliferation of Toxoplasma gondii tachyzoites in sw480 cells was observed by Giemsa staining,and the growth inhibition rates of these cells were investigated by the CKK-8 method.Meanwhile,the apoptosis and necrosis of sw480 cells were detected with transmission electron microscopy (TEM) and fluorescence microscopy with Hochest 33258 staining to observe the morphological changes of sw480 cells.Agarose electrophoresis was used to detect the DNA change of sw480 cells,and flow cytometric analysis was used for investigation of rates of apoptosis and necrosis of these cells stained with Annexin-v-FITC/PI.It was found that the parasitism and proliferation of Toxoplasma gondii tachyzoites in sw480 cells could be observed;and as demonstrated by the CKK-8 method,the inhibitive effect of the co-culture supernatant depended upon the treatment time,and a maximum inhibition ratio of 44.55% was detected at 48 hours.The karyopyknosis and karyorrhexis in the treated sw480 cells were observed under the fluorescence microscope;and the cellular necrosis were observed under TEM.In addition,the DNA fragments in the treated cells were revealed by agarose electrophoresis.In the flow cytometric analysis,a maximum prophase apoptosis rate of 11.54% was detected at 48 hours after treatment with the supernatants,while the rate of prophase apoptosis decreased,and the rates of advanced stage/necrosis increased markedly at the treatment time beyond 48 hours.It is concluded that the co-culture supernatant of Toxoplasma gondii and human colon cancer cell sw480 cell line can induce inhibition of proliferation,apoptosis and necrosis of this cell line in vitro.
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Cancer development is accompanied by genetic events like losses, gains and amplification of certain chromosome regions or alterations of chromatin structure. Array-based CGH (Array-CGH) is a highly comprehensive, sensitive and fast technique to allow investigation of general changes in target oncogenes and tumor suppressor genes. Recently, the prevalence of colon cancer is rapidly increasing in Korea and now it is the fourth leading cause of cancer death. So, the purpose of this study is to examine genomic alterations in colon cancer cell lines and to search novel genes which might be related to the development of colon cancer. In this study, genomic alterations are analyzed by using array-CGH in three colon cell lines from Korean, SNU-81, SNU-407 and SNU-1047. We observed numerous chromosomal imbalances from all cell lines. The common chromosomal gains were observed in 1p36.33, 1q22, 1q32.1, 2q35, 8p12, 8q22.3, 14q32.33, 16p13.3, and 16q24. Common chromosomal losses were found in 4q22.1, 9q13, 14q21.1, 14q32.33, 20p12.1, Xq21.1, and Yq11.223. Gains of 1p, 2q, 8p, and 8q or losses of 4q, 14q and 20p are already known to be associated with the colon cancer development. For gene alterations, we could see gains of some genes such as ELF3 and AAMP, which were already reported to be associated with colon cancer. Also, we could find some gene alterations which were known to be associated with other cancer types. These genes were GON4L, RNPEP, TMBIM1, TIMM17A, GPBAR1, PPP1R13B and SOX8. Besides, we found alterations of new genes such as PKND and LEPROTL1. The association of these genes with colon cancer is first demonstrated here. These genes may be the novel candidate genes functioning in the development of colon cancer. In conclusion, array-CGH demonstrated the complexity of genetic aberrations in several colon cell lines. These data about the patterns of genomic alterations could be a basic step for understanding more detailed genetic events in the carcinogenesis and also provide information about possible target genes for diagnosis and treatment in colon cancer.
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Cell Line , Chromatin , Colon , Colonic Neoplasms , Genes, Tumor Suppressor , Korea , Nucleic Acid Hybridization , Oncogenes , PrevalenceABSTRACT
PURPOSE: This study was undertaken to reveal the molecular mechanism underlying sulindac-induced apoptosis in the human colon cancer cell line HT-29 (mutant p53). METHODS: Apoptosis was determined by using Hoechst 33342 staining, and translocation of proteins was established by using immunofluorescence, immunoelectron microscopy, and Western blotting after ultra- fractionation. RESULTS: This type of apoptosis was associated with decreased mitochondrial membrane potential, a translocation of the apoptosis-inducing factor (AIF) to the nucleus, and morphological evidence of nuclear condensation. However, DNA electrophoresis did not elucidate the ladder pattern of DNA fragments. Instead, a pulse-field gel electrophoresis showed that sulindac led to disintegration of nuclear DNA into-high- molecular-weight DNA fragments of about 100~300 kbp. CONCLUSIONS: Our findings indicate that sulindac induces large-scale DNA fragmentation, suggesting a predominantly AIF-mediated cell-death process, through translocation of the AIF to the nucleus in HT-29 cells.
Subject(s)
Humans , Apoptosis Inducing Factor , Apoptosis , Blotting, Western , Cell Line , Colonic Neoplasms , DNA Fragmentation , DNA , Electrophoresis , Fluorescent Antibody Technique , HT29 Cells , Membrane Potential, Mitochondrial , Microscopy, Immunoelectron , SulindacABSTRACT
BACKGROUND: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost . In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. METHOD: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. RESULTS: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. CONCLUSION: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.
Subject(s)
Animals , Cats , Humans , Alleles , Arginine , Blotting, Northern , Blotting, Western , Carcinogenesis , Cell Line , Cell Proliferation , Codon , Colon , Colonic Neoplasms , Exons , Genes, p53 , Genes, Tumor Suppressor , Histidine , Immunoprecipitation , Incidence , Mutation, Missense , Point Mutation , RNA, Messenger , Sequence Analysis, DNA , Transcriptional ActivationABSTRACT
Objective To analyze the effect of eukaryotic expression vector containing sense and antisense DNA methyltransferase (DNMT1) gene on the transcript level of tumor associated genes in human colon cancer cell line. Methods Recombinant plasmid, including sense DNMT1 (HMT) and antisense DNMT1 (THM) gene, were constructed and transfected into SW1116 cell by using the lipofectamine. Then G418 filtration was performed. The expression of DNMT1 protein was examined by Western blotting. The transcription level of hMLH1, hMSH2, c myc and p16 INK4A genes were detected by RT PCR. Results The sense and antisense eukaryotic expression vectors were successfully constructed and then the constructed recombinant plasmids were transfected into SW1116 cell. The protein levels of DNMT1 have been up regulated and down regulated in SW1116 cells transfected with HMT and THM plasmids, respectively. The mRNA level of hMLH1, hMSH2, c myc gene were down regulated in the sense DNMT1 transfected cell. The mRNA level of hMSH2 was up regulated in the antisense DNMT1 transfected cell. However, the transcription level of p16 INK4A gene could not be associated with DNMT1 in SW1116 cell.Conclusion DNMT1 can regulate the expression of the tumor associated genes in human colon cancer cell line SW1116.
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0.05). Conclusions The expression of XAF1 decreases in both malignant and benign colo-rectal tumors and is significantly lower in colorectal carcinomas than in adenomas/polyps. Thus, XAF1 may have the potential role in differentiating colorectal cancer from benign tumors.