Two novel gastric cancer-associated genes identified by differential display

AIM To clone novel gastric cancer-associated genes and investigate their roles in gastric cancer occurrence.METHODS A method called differential display was used which allows the identification of differentially expressed genes by using PAGE to display PCR-amplified cDNA fragments between gastric cancer cells and normal gastric mucosa cells. These fragments were cloned into plasmid vector pUC18. Homology analysis was made after sequencing these fragments.RESULTS Two novel genes were identified compared with sequences from GenBank. One was registered with the AD number AF 051783. In situ hybridization showed that these two novel genes expressed specifically in gastric cancer tissues.CONCLUSION The two novel genes obtained by differential display were confirmed to be gastric cancer-associated genes using in situ hybridization.     

精神分裂症患者致炎性细胞因子和酪氨酸羟化酶mRNA表达水平的研究

目的探讨精神分裂症的外周神经免疫机制及其与临床症状的关系。方法检测精神分裂症患者致炎性细胞因子白介素-1β（IL-1β）、肿瘤坏死因子-α（TNF—α）以及酪氨酸羟化酶（TH）的mRNA表达水平，采用逆转录-聚合酶链反应及半定量检测技术，分别检测39例精神分裂症患者（患者组）、25例同胞（同胞组）及30名正常对照（对照组）外周血单个核细胞（PBMC）IL-1β、TNF-α及TH基因表达水平，同时应用阳性和阴性症状量表（PANSS）评定精神分裂症患者临床症状。结果患者组、同胞组及对照组IL-1β的mRNA表达水平分别为1．52±1．01、1．52±1．09和0．74±0．38；TNF—α的mRNA表达水平分别为1．18±0．99、1．01±0．87和0．70±0．29；TH的mRNA表达水平分别为0．55±0．33、0．61±0．32和0．28±0．20。患者组和同胞组的IL-1β、TNF—α、TH的mRNA表达水平均明显高于对照组（P〈0．05或P〈0．01）。患者组IL-1β（r=0．420）、TNF—α（r=0．430）的mRNA表达水平与PANSS的-般病理症状分呈正相关（P〈0．01）。同胞组与对照组合并统计，IL-1β与TNF-α的mRNA表达水平呈正相关（r=0．847，P〈0．01）；IL-1β与TH的mRNA表达水平呈正相关（r=0．666，P〈0．01）。患者组仅IL-1β与TNF—α的mRNA表达水平呈正相关（r=0．942，P〈0．01）。结论精神分裂症患者PBMC细胞TH、IL-1β和TNF—α的mRNA表达水平高于正常，且与精神分裂症的-般病理症状显著相关。     

慢性神经病理性痛大鼠背根神经节P2Y2受体mRNA的表达

目的评价背根神经节（DRG）P2Y2受体mRNA的表达在大鼠慢性神经病理性痛中的作用。方法SPF级大鼠24只,体重150～200g,雌雄不拘,随机分为2组：假手术组（S组）和慢性神经痛组（N组）,每组12只。N组结扎左侧坐骨神经建立大鼠慢性压迫性损伤（CCI）模型,S组只暴露,不结扎左侧坐骨神经。2组分别于CCI前1d、CCI后1、4、7、10、14 d进行行为学观察,测定大鼠双后肢热痛阈和机械痛阈,并分别于CCI后7、14 d各取6只大鼠断颈处死,取双侧L（4-6）背根神经节,RT-PCR法测定P2Y2受体mRNA的表达。结果两组CCI后4 d热痛阈、机械痛阈明显降低（P〈0.05）,持续至CCI后14 d;N组左侧DRG P2Y2受体mRNA表达较右侧明显下调,CCI后14 d较CCI后7 d下调（P〈0.05）;与S组右侧比较,N组DRG P2Y2受体mRNA表达差异无统计学意义（P〉0.05）。结论背根神经节P2Y2受体mRNA的表达下调参与了大鼠慢性神经病理性痛的形成。     

糖皮质激素对哮喘患者白细胞介素-5mRNA表达与嗜酸性粒细胞激活作用的影响

为了观察糖皮质激素对哮喘患者白细胞介素（ＩＬ）－５ｍＲＮＡ表达与嗜酸性粒细胞激活作用的影响，本研究用逆转录（ＲＴ）－聚合酶链反应（ＰＣＲ）法半定量分析了哮喘患者用糖皮质激素治疗前后外周血单个核细胞（ＰＢＭＣ）中ＩＬ－５ｍＲＮＡ表达水平的变化，检测了血清嗜酸细胞阳离子蛋白（ＥＣＰ）浓度、一秒钟用力呼气容积（ＦＥＶ１）下降２０％时的乙酰甲胆碱（ＭＣＨ）激发浓度（ＭＣＨ－ＰＣ２０值）和基础ＦＥＶ１占用力肺活量比值（ＦＥＶ１％）等指标。结果发现，糖皮质激素不仅能改善哮喘患者的气道高反应性和通气功能，而且还可抑制ＰＢＭＣ中ＩＬ－５ｍＲＮＡ的表达和降低血清ＥＣＰ浓度（Ｐ＜０．０５）；血清ＥＣＰ浓度下降幅度或ＭＣＨ－ＰＣ２０值改善幅度与ＩＬ－５ｍＲＮＡ表达水平下降幅度之间均呈显著正相关（ｒ分别为０．５４２６和０．４８５７，Ｐ值＜０．０５）。提示糖皮质激素可能是通过抑制ＩＬ－５基因的转录，从而抑制后者对嗜酸性粒细胞的活化，而发挥其抗气道炎症反应和降低气道高反应性的作用。     

A cDNA for the estradiol-regulated 24K protein: Control of mRNA levels in MCF-7 cells

We have previously demonstrated an estradiol-regulated 24 kDa (24K) protein in human breast cancer tissue culture cells and human tumor biopsies. The presence of 24K correlates well with the presence of steroid hormone receptors. In order to further study the hormonal regulation of the 24K protein and gene, we have isolated cDNA clones corresponding to the 24K mRNA.Poly(A)⁺ RNA isolated from the MCF-7 human breast cancer cell line was translated in a cell-free translation system containing [³⁵S]-methionine. The translation products were immunoprecipitated with a 24K monoclonal antibody, and thein vitro synthesis of 24K protein was confirmed by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis. The same poly(A)⁺ RNA was used to construct an oligo(dT)-primed cDNA library in thegt11 expression vector system. The library was screened with a highly specific polyclonal antibody raised against 24K protein purified by immunoaffinity chromatography. Four recombinant clones reacting with the antibody by virtue of antigen expression were isolated and three were used in hybridization-selected translation. Three clones were able to hybridize specifically to a messenger RNA (mRNA) that yielded a Mr 24,000 protein when translatedin vitro and analyzed by SDS/polyacrylamide gel electrophoresis. This protein was also immunoprecipitable by the 24K monoclonal antibody. MCF-7 mRNA size fractionated by formaldehyde-agarose gel electrophoresis was transferred to nitrocellulose paper and hybridized to a nick-translated 24K cDNA clone. A single band of hybridization corresponding to a mRNA size of approximately 0.9–1.0 kilobase (kb) was observed. Using this same technique, 24K cDNA was hybridized to mRNA extracted from MCF-7 cells that had been treated for varying periods with either estradiol, nafoxidine, or tamoxifen. The 24K mRNA was elevated by the addition of estradiol, and clearly diminished by nafoxidine and tamoxifen.These results demonstrate that we have isolated cDNA clones for the study of the hormonal regulation of the 24K gene in breast cancer cells, and have shown that the mRNA is regulated by estradiol.     

人细胞色素P450 前mRNA的可变剪接研究进展

Human genes typically contain multiple introns, and in many cases the exons can be joined more than one way to generate multiple rnRNAs, encoding distinct protein isoforms. This process is called alternative splicing. The article summarized the human cytochrome P450 pre-mRNA alternative splicing and their regulatory mechanism and impacts on biological functions.     

Changes in neurofilament gene expression occur after axotomy of dorsal root ganglion neurons: Anin situ hybridization study

Neurofilaments (NFs) are predominant elements in large myelinated axons, where they are thought to serve the important function of maintaining axonal caliber. Previous studies have shown that changes in NF synthesis and axonal transport occur after axonal injury in rat dorsal root ganglion (DRG) cells. The resulting reduction in the NF supply to DRG axons is thought to be largely responsible for the observed decrease in axonal diameter in the proximal axonal stump after an injury. In the present study, we test the hypothesis that a change in NF gene expression precedes the changes in synthesis and transport of NF proteins. To address this hypothesis, the levels of mRNA encoding the 68-kilodalton (kd) neurofilament protein (NF68) in adult rat DRG neurons were assessed at different times after peripheral axotomy usingin situ hybridization. For these studies we used a³⁵S-labeled cDNA probe to NF68. The levels of NF68 mRNA in sensory neurons located in ipsilateral fourth and fifth lumbar DRG at 1, 7, and 14 days after sciatic nerve crush were compared to those in normal DRG neurons using quantitative autoradiography. In large DRG neurons (> 1000m²), the levels of NF68 mRNA were significantly reduced relative to normal at 1, 7, and 14 days after axotomy. Medium-sized cells (601–1000m²) exhibited a reduction only at 14 days postinjury, and small-sized cells were not significantly affected. These findings indicate that larger DRG neurons which give rise to large myelinated sensory axons exhibit a change in NF gene expression after axonal injury. The observed changes in NF68 mRNA levels temporally precede changes in NF synthesis and transport in injured DRG cells. Thus, a change in NF gene expression may be an important component of an effective regenerative response and a critical step at which axonal caliber is regulated in injured neurons.     

人大肠癌中基质金属蛋白酶-7 mRNA的表达

目的:探讨基质金属蛋白酶-7(matrix metalloproteinase 7,MMP-7)与大肠癌浸润和转移的关系.方法:用逆转录聚合酶链式反应(RT-PCR)检测大肠癌和正常黏膜、炎性息肉、腺瘤及淋巴结中MMP-7 mRNA的表达.结果:97.4%(37/38)的大肠癌和1例肝转移中MMP-7 mRNA表达阳性,而相应正常黏膜几乎不表达;大肠癌中MMP-7 mRNA的表达水平随Dukes分期的进展而逐渐升高(P＜0.01),A期(0.28±0.08),B期(0.54±0.17),C期(0.55±0.09),D期(0.73±0.06).5例腺瘤MMP-7均为阳性,但表达水平低于癌组织(P＜0.01);3例炎性息肉均未见MMP-7表达.传统组织学检查有癌转移的13个淋巴结MMP-7表达均为阳性;组织学检查未见转移的12个淋巴结MMP-7表达6个阴性、6个阳性,再次行组织学检查于6个MMP-7阳性者中发现3个有微转移.结论:MMP-7的高表达可能在大肠癌的浸润和转移过程中具有重要作用;用RT-PCR方法检测淋巴结中MMP-7mRNA的表达是诊断大肠癌淋巴结微转移的敏感方法.     

α1B- but not α1A-adrenoceptors mediate inositol phosphate generation

Summary We used novel highly subtype-selective antagonists to study whether _1A- and/or _1B-adrenoceptors mediate the stimulation of inositol phosphate generation by noradrenaline in rat cerebral cortex. Phentolamine (10 M) and prazosin (100 nM) completely abolished the stimulated inositol phosphate generation. The _1A-selective antagonists 5-methyl-urapidil (100 nM) and (+)– and (–)-niguldipine (10 nM) caused only weak inhibition or none at all although these concentrations occupied _1A-adrenoceptors almost completely. In contrast, pretreatment with the irreversible _1B-selective chloroethylclonidine reduced the noradrenaline-stimulated inositol phosphate generation by 76 ± 8%. These data demonstrate that _1B-adrenoceptors couple to inositol phosphate generation; the signal transduction system of _1A-adrenoceptors remains unclear. Send offprint requests to G. Gross at the above address