miRNA-149在口腔鳞状细胞癌中的表达及其临床意义

目的：通过对比检测口腔鳞癌患者肿瘤组织与癌旁组织miRNA-149的表达水平,分析其在口腔鳞癌中潜在的临床意义。方法：收集28例口腔鳞癌患者的肿瘤组织及其2cm癌旁组织,通过实时定量PCR反应检测miR-149在二者间的表达水平江分析其水平与口腔鳞癌患者性别、年龄、吸烟史、TNM临床分期以及病理分级之间的相关性。结果：口腔鳞癌患者肿瘤组织中miR-149的表达水平显著低于对照组,且发现miR-149的表达水平在有淋巴结转移的、TNM临床分期较晚以及病理分化较差的肿瘤中明显降低。结论：miR-149在口腔鳞癌患者肿瘤组织中表达显著下调,其表达水平与肿瘤的淋巴结浸润、转移以及病理分级有着重要的关系,从而miR-149可能会成为将来判断口腔鳞癌临床分期的一个重要的标记物。     

microRNA-149在顺铂耐药非小细胞肺癌细胞中的表达变化及相关机制研究

目的探讨microRNA-149(miR-149)在顺铂耐药A549细胞(A549/DDP)中的表达规律及作用机制。方法生物信息学方法分析顺铂耐药A549细胞中的microRNA表达变化。体外培养A549细胞并诱导对顺铂耐药的A549/DDP细胞系,实时荧光定量PCR(qRT-PCR)检测miR-149在两种细胞系中的表达差异。CCK-8试验及流式细胞术检测单纯miR-149过表达以及miR-149和ABCC1同时过表达对细胞顺铂敏感性的影响。qRT-PCR及Western blot检测A549及A549/DDP细胞中ABCC1的表达差异,双荧光素酶报告试验检测miR-149以ABCC1之间的靶向关系,并利用qRT-PCR及Western blot加以证实。结果 A549/DDP细胞中的miR-149表达较低,与A549细胞相比,差异具有统计学意义(t=-4.65,P0.05)。miR-149过表达可以降低顺铂处理后A549/DDP细胞的活力但增加其凋亡率,与阴性转染对照细胞相比,差异具有统计学意义(P均0.05)。与A549细胞相比ABCC1在A549/DDP细胞中存在mRNA及蛋白水平的高表达,差异具有统计学意义(t=8.44、5.14,P均0.05)。过表达miR-149可以降低A549/DDP细胞中ABCC1的mRNA及蛋白水平,与阴性转染对照细胞相比,差异具有统计学意义(t=-3.14、-4.54,P0.05)。双荧光报告酶分析显示miR-149可直接与ABCC1 mRNA的3’UTR结合。miR-149与ABCC1同时过表达的A549/DDP细胞与单纯miR-149过表达的细胞相比,顺铂处理后细胞活力增加,凋亡减少,差异具有统计学意义(P均0.05)。结论 miR-149表达不足可能引起A549细胞对顺铂的耐药,该机制与miR-149对ABCC1的抑制作用有关。     

miR-149 represses metastasis of hepatocellular carcinoma by targeting actin-regulatory proteins PPM1F

microRNAs have been implicated in hepatocellular carcinoma (HCC) metastasis, which is predominant cause of high mortality in these patients. Although an increasing body of evidence indicates that miR-149 plays an important role in the growth and metastasis of multiple types of cancers, its role in the progression of HCC remains unknown. Here, we demonstrated that miR-149 was significantly down-regulated in HCC, which was correlated with distant metastasis and TNM stage with statistical significance. A survival analysis showed that decreased miR-149 expression was correlated with a poor prognosis of HCC as well. We found that over-expression of miR-149 suppressed migration and invasion of HCC cells in vitro. In addition, we identified PPM1F (protein phosphatase, Mg²⁺/Mn²⁺-dependent, 1F) as a direct target of miR-149 whose expression was negatively correlated with the expression of miR-149 in HCC tissues. The re-expression of PPM1F rescued the miR-149-mediated inhibition of cell migration and invasion. miR-149 regulated formation of stress fibers to inhibit migration, and re-expression of PPM1F reverted the miR-149-mediated loss of stress fibers. Moreover, we demonstrated that over-expression of miR-149 reduced pMLC2, a downstream effector of PPM1F, in MHCC-97H cells. In vivo studies confirm inhibition of HCC metastasis by miR-149. Taken together, our findings indicates that miR-149 is a potential prognostic biomarker of HCC and that the miR-149/PPM1F regulatory axis represents a novel therapeutic target for HCC treatment.     

The toxic fraction of gliadin digests in coeliac disease. Isolation by chromatography on Biogel P-10

Improvement in the fractionation of gliadin digests and in the isolation of toxic fractions was achieved using chromatography on Biogel P-10. Fraction V, one of the 11 fractions eluted from a peptic-tryptic digest of crude gliadin extracted from Cappelle wheat, significantly affected coeliac jejunal mucosa in organ culture. BV, gamma V, omega V, the corresponding fractions V from beta-, gamma- and omega-gliadins, displayed similar toxic effects. Fraction VI containing peptides with a lower molecular mass did not show any significant cytotoxic activity and, moreover, inhibited the toxicity of fraction V. Analysis of the toxic fractions V showed that they contained peptides of 7-8,000 molecular mass, rich in proline and glutamine and poor in aromatic amino acids and carbohydrates. Among the various fractions, V, beta V from beta-gliadin appeared the less heterogeneous.