On the Activity of Alkaline Phosphatase in Intestinal Mucosa from Casein-fed Rats

A novel optical activity of lutein was studied in dodecyltrimethylammonium bromide (DTAB) solution by the measurement of circular dichroism and absorbance. The surfactant was found to bring about the circular dichroism activity of the lutein below the critical micelle concentration (CMC) in a different way from that by sodium dodecyl sulfate (SDS). This phenomenon was interpreted by the card-pack model of the lutein aggregate in which lutein molecule was slightly shifted each other. The above optical activity abruptly became strong just before the CMC of DTAB. This seems to correspond to the transition from the polymeric aggregate of the lutein to the oligomeric one. Such an optical activity disappeared beyond the CMC on the incorporation of the lutein molecules into the surfactant micelles. The molar binding ratios of DTAB to the lutein were determined to be 130 to 210 on the basis of the lutein concentration dependence of the DTAB concentration showing the arbitrary ellipticity. These ratios were clearly larger than those for SDS. On the other hand, filtration measurement showed that the size of the lutein-DTAB complex was larger than 2 μm in diameter. These phenomena were discussed assuming the possible model of the aggregate as a comparative study of the anionic and cationic surfactants causing the novel optical activity of this aggregate.     

miRNA参与肿瘤基因表达调控研究进展

调查表明,我国城乡居民恶性肿瘤死亡率属于世界较高水平,而且呈持续的增长趋势。近年来的研究发现在肿瘤的发生与发展过程中涉及到多种因素,其中mi RNA可能扮演了重要的作用。mi RNA是一种长度约为22 nt的非编码短序列RNA,通过介导特异性的基因沉默导致靶m RNA降解,促使相应蛋白质的转译受阻而失去原有编码蛋白质的功能。mi RNA在细胞分裂周期中影响着基因的表达调控,在此过程中基因表达的失控就可能导致疾病的发生。而肿瘤的发生是以细胞恶变为基础,细胞恶变则是与细胞周期调控因素失衡相关,由此提示了一些mi RNA可能参与了肿瘤的发生、发展过程并在其中发挥了重要作用。随着研究的深入,mi RNA逐渐成为肿瘤诊治的新研究方向。本文主要讨论mi RNA在肿瘤基因表达调控方面的研究进展。     

遗传性骨病致病基因及相关miRNA的相互作用分析

目的:筛选遗传性骨病相关的致病基因和其相关的mi RNA,并研究两者相互作用关系以及在遗传性骨病中的作用。方法:本研究应用生物信息学的方法,首先应用mirwalk和《国际遗传性骨病分类标准》分析遗传性骨病的致病基因,根据筛选出来的致病基因利用mirwalk的10个预测mirna搜索引擎功能,搜索致病基因的相关mi RNA,并应用excel工作表统计分析mirna的靶向致病基因;再应用Cytoscape软件分析致病基因和相关mirna之间的相互作用关系。结果:本研究中与遗传性骨病密切相关的基因可以分为四类:第一类为成骨不全类基因COL1A1、COL1A2等;第二类为骨密度降低类基因如ACVR1、ALX1等;第三类为骨密度增加类基因如CASR、DMTF1等;第四类为通过作用骨干参与骨密度增加的基因如TGFBR1、MYCN等。其中与成骨不全关系最为密切的mirna是hsa-miR-26b、hsa-miR-19、hsa-miR-200c;与骨密度降低关系最为密切的mirna是hsa-miR-138、hsa-miR-505;与骨密度增加关系最为密切的mirna是hsa-miR-196a、hsa-miR-200b、hsa-miR-19b。结论:mirna可通过调控遗传性骨病致病基因在其病理过程中起到重要作用,提示上述mirna可能是成为遗传性骨病产前筛查和临床药物治疗的新靶点。     

Small non‐coding RNA and colorectal cancer

Colorectal cancer (CRC) is the third most common malignance. Although great efforts have been made to understand the pathogenesis of CRC, the underlying mechanisms are still unclear. It is now clear that more than 90% of the total genome is actively transcribed, but lack of protein‐coding potential. The massive amount of RNA can be classified as housekeeping RNAs (such as ribosomal RNAs, transfer RNAs) and regulatory RNAs (such as microRNAs [miRNAs], PIWI‐interacting RNA [piRNAs], tRNA‐derived stress‐induced RNA, tRNA‐derived small RNA [tRFs] and long non‐coding RNAs [lncRNAs]). Small non‐coding RNAs are a group of ncRNAs with the length no more than 200 nt and they have been found to exert important regulatory functions under many pathological conditions. In this review, we summarize the biogenesis and functions of regulatory sncRNAs, such as miRNAs, piRNA and tRFs, and highlight their involvements in cancers, particularly in CRC.