Flavonol-rich fractions of yaupon holly leaves (Ilex vomitoria, Aquifoliaceae) induce microRNA-146a and have anti-inflammatory and chemopreventive effects in intestinal myofibroblast CCD-18Co cells

Polyphenolics extracted from yaupon holly (Ilex vomitoria, Aquifoliaceae) (YH) leaves were investigated in human colon cells for their chemopreventive and anti-inflammatory activities. An activity-guided fractionation allowed the selection of YH flavonol-rich fraction due to its preferential inhibition of HT-29 colon cancer viability over the normal CCD-18Co colon cells. Quercetin and kaempferol 3-rutinosides, main components identified in this fraction, protected CCD-18Co cells against reactive oxidative species (ROS) in part due to increased activity of antioxidant enzymes. In addition, up-regulation of microRNA-146a (miR-146a) known as a negative regulator of pro-inflammatory NF-κB activation was the underlying molecular mechanism that protected CCD-18Co from inflammation.     

Feline urological syndrome

CASE HISTORY: Torsion of the descending colon was diagnosed by barium enema radiography in an adult Irish Water Spaniel which had presented with tenesmus of 24 h duration. Treatment involved exploratory laparotomy, repositioning of the colon, colopexy and repair of a mesenteric rent. No definitive cause of the torsion could be established. The dog made an uneventful recovery from surgery.

CLINICAL RELEVANCE: Animals presenting with constipation of undetermined cause should have large intestinal obstruction ruled out prior to administering bowel cleansing solutions per os and/or colonic enemas. Colonic obstruction by torsion should be considered as a possible differential diagnosis in all cases of tenesmus.     

大豆皂醇抗结肠癌作用的研究

大豆皂甙通过促进肿瘤细胞凋亡可抑制多种肿瘤细胞的增殖.采用C18反相柱层析法从大豆胚轴提取大豆皂甙,再将其部分水解成其甙元大豆皂醇,研究其抗结肠癌细胞增殖作用.采用MTr比色法观察大豆皂醇对结肠癌HT-29细胞增殖的影响,采用TUNEL染色法检测其对HT-29细胞凋亡的影响.结果表明:大豆皂醇在40-160mg·L-1范围内可时间和浓度依赖性地抑制结肠癌细胞增殖和诱导细胞凋亡.用80 mg·L-1大豆皂醇A和B作用结肠癌细胞72 h时,细胞生长抑制率分别为(48.7±1.3)%和(42.6±2.0)%;其对肿瘤细胞凋亡率分别为(37.0±1.2)%和(29.5±0.7)%.提示,大豆皂醇可通过诱导细胞凋亡发挥抗结肠癌作用.     

大熊猫肠梗阻非手术性治疗的研究

肠梗阻是野外及圈养条件下大熊猫急腹症中的一种多发病,由食物,水份等多种因素引起,该症起病急,发展迅速,症状严重,死亡率高,对其治疗,曾采用手术疗法,纵切堵塞肠管,取出粪团,但易感染引起并发症,其预后不良。使用上攻下疏治疗方法,对其直肠或结肠,直肠梗阻有一定疗效。本文采用中西结合,上攻下疏,全身综合治疗方法,对４全 肠,结肠梗阻个体,缩短了疗程,快速取出了堵塞粪团,使４例个体早日恢复了健康。     

中药口服液治疗人工感染仔猪大肠杆菌试验研究

用茜草秧、穿心莲、大青叶等13味中药组方,制成口服液口服给药,对仔猪大肠杆菌耐药菌株和非耐药菌株进行体外抑菌及临床治疗试验.结果,中药口服液对两菌株都有较好的体外抑菌效果;临床治疗有效率100%,治愈率达90%以上.     

miR-496 over-expression inhibits growth and metastasis in colon cancer cells

AIM: To investigate the effect of miR-496 over-expression on the growth and metastasis of colon cancer cells and its molecular mechanism.METHODS: The proteins interacting with miR-496 were screened by bioinformatic method. The levels of miR-496, CTNNB1 mRNA and β-catenin protein in colon cancer cell lines, HT29, HCT116 and SW480, and normal colonic epithelial cell line NCM460 were detected by real-time PCR and Western blot. HT29, HCT116 and SW480 cells were transfected with miR-496 mimics using Lipofectamine 2000 and named as HT29-miR-496 mimics, HCT116-miR-496 mimics and SW480-miR-496 mimics cells, respectively, and the cells transfected with the scramble served as negative control. The cell viability, lactate dehydrogenase (LDH) leakage, and colony formation and metastatic abilities were determined by MTT assay, LDH assay, colony formation assay and Transwell method, respectively. The promoter activity of miR-496 was measured using luciferase reporter gene assay. The protein levels of β-catenin, eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), p-4E-BP1, low-density lipoprotein receptor-related protein 6(LRP6), p-LRP6, MMP-7, MMP-9, MMP-13 and TIMP-2 were monitored by Western blot.RESULTS: Endogenous miR-406 interacted with β-catenin was found in the colon cancer cells. Low miR-496 expression in the HT29, HCT116 and SW480 cells and high miR-496 expression in NCM460 cells were detected. In contrast, high β-catenin expression was found in the HT29, HCT116 and SW480 cells and low β-catenin expression was observed in the NCM460 cells. Compared with control group, the cell viability, colony formation rate and the number of metastatic cells remarkably decreased in the HT29-miR-496 mimics, HCT116-miR-496 mimics and SW480-miR-496 mimic cells (P<0.05). The promoter activity of miR-496 was significantly increased in colon cancer cells transfected with miR-496 mimics, and was 1.75, 2.04 and 1.61 times as high as control group. miR-496 over-expression inhibited β-catenin levels, and p-4E-BP1 and p-LRP6 protein levels were also reduced. siRNA- or over-expressed miR-496-mediated β-catenin down-regulation inhibited MMP-7 and MMP-9 expression, but promoted TIMP-2 expression.CONCLUSION: The expression level of miR-496 in the colon cancer cells is low, but in the normal colonic epithelial cells is high. miR-496 over-expression inhibits the protein levels of MMP-7 and MMP-9, and promotes the protein expression of TIMP-2 via inhibiting Wnt/β-catenin pathway, thus suppressing malignant phenotype in the colon cancer cells.     

大豆异黄酮甙元对结肠癌HT-29细胞增殖和凋亡的影响

大豆异黄酮通过促进肿瘤细胞凋亡可抑制多种肿瘤细胞的增殖.从大豆提取大豆异黄酮糖甙,再将其部分水解成其甙元,研究大豆异黄酮甙元抑制结肠癌细胞的增殖和促进其凋亡的作用.采用MTT比色法观察大豆异黄酮甙元对结肠癌HT-29细胞增殖的影响,采用TUNEL染色法检测其对HT-29细胞凋亡的影响,采用免疫细胞化学法检测凋亡相关蛋白bax、bcl-2和p53的表达.结果表明:大豆异黄酮甙元可在20～80 mg·L-1范围内时间和浓度依赖性地抑制结肠癌HT-29细胞增殖和诱导细胞凋亡.用40 mg·L-1大豆异黄酮甙元作用结肠癌HT-29细胞72 h时,细胞生长抑制率为(57.1±4.9)%,其对肿瘤细胞凋亡率为(20.9±2.1)%.免疫组化结果还显示,大豆异黄酮甙元可显著性增加HT-29细胞凋亡相关基因bax蛋白表达和降低bcl-2表达.提示,大豆异黄酮甙元可通过诱导结肠癌细胞凋亡发挥抗结肠癌作用.     

Effects of miR-337 targeting p53 expression on autophagy and migration ability of colon cancer cells

AIM: To investigate the effect of microRNA-337 (miR-337) on the autophagy and migration ability of colon cancer cells, and to explore its possible mechanism involving targeting p53 expression. METHODS: The me-thod of immunohistochemistry was used to detect the protein expression of beclin-1, LC3B and p53 in colon cancer tissues. The correlations between the protein expression of beclin-1/LC3B and clinicopathological features, and the correlations between the protein expression of p53 and beclin-1/LC3B were analyzed. After knock-down of p53 expression by small interfering RNA, the formation of autophagiosomes was observed under electron microscope in colon cancer cell line HCT116, and the protein expression of beclin-1 and LC3B was determined by Western blot. The miRNAs targeting p53 were predicted and screened by bioinformatics, and their expression in HCT116 cells was verified by RT-qPCR. Luciferase reporter assay was used to detect the regulatory effect of miR-337 on p53 gene. The protein expression of p53, beclin-1 and LC3B was determined by Western blot, and the migration ability of HCT116 cells after miR-337 over-expression was detected by Transwell assay. RESULTS: The protein expression of beclin-1 and LC3B in the colon cancer tissues was decreased, which was significantly related to the occurrence, development, invasion and metastasis of colon cancer. The expression of p53 was increased in the colon cancer tissues, which was negatively correlated with the protein expression of beclin-1 and LC3B. Knock-down of p53 gene expression increased the protein expression of beclin-1 and LC3B (P<0.05). Over-expression of miR-337 down-regulated the expression of p53, up-regulated the protein expression of beclin-1 and LC3B, and decreased the migration ability of HCT116 cells (P<0.05). CONCLUSION: miR-337 promotes autophagy and inhibits migration ability of colon cancer cells, and the mechanism may be related to targeted inhibition of p53 expression.     

Effect of Wip1 gene silencing on chemotherapy sensitivity of human colon cancer cells

AIM: To observe the inhibitory effect of siRNA targeting to Wip1 gene on the Wip1 gene expression in the colon cancer cells and to investigate the influence of Wip1 gene silencing on the chemotherapy sensitivity of colon cancer cells. METHODS: Wip1-811 siRNA targeting to Wip1 gene was transfected into RKO colon cancer cells with high expression of Wip1 gene. The mRNA expression of Wip1 was measured by real-time PCR. The protein level of Wip1 was detected by Western blotting. The viability of RKO colon cancer cells was measured by MTS assay. The cell apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: Wip1-811 siRNA efficiently inhibited the expression of Wip1 at mRNA and protein levels. The enhanced chemotherapy sensitivity of RKO colon cancer cells was observed after inhibition of Wip1 gene expression. The viability of RKO colon cancer cells was decreased from (89.4±6.6)% to (74.7±3.9)% after treated with 5-fluorouracil (P<0.05) and decreased from (77.9±2.4)% to (66.7±2.9)% after treated with oxaliplatin (P<0.05). The cell apoptotic rate was increased from (7.7±0.5)% to (12.3±3.2)% and from (14.7±2.1)% to (34.0±2.1)% when RKO colon cancer cells were treated with 5-fluorouracil and oxaliplatin, respectively (P<0.05). CONCLUSION: Wip1 gene silencing enhances chemotherapy sensitivity of colon cancer cells.