肺癌胰岛素样生长因子-2基因印迹的研究

目的探讨胰岛素样生长因子-2(IGF2)基因印迹(genomicimprinting)与肺癌发生发展过程的关系。方法于2003年1月至2004年1月,对大连医科大学附属第一医院胸外科手术切除的标本,根据IGF2基因第9外显子具有ApaI位点多肽性,利用聚合酶链反应(PCR)技术结合限制性片段长度多态性(RFLP)技术,诊断的32例肺癌患者及其对应的癌周正常肺组织进行了IGF2基因印迹的研究。结果12例患者为杂合子信息个体(37·5%),其中10例为IGF2双等位基因表达,即发生了基因印迹缺失(LOI,83·3%),而且这10例病人中有4例的癌周正常肺组织表现为IGF2弱的双等位基因表达。结论IGF2基因的印迹缺失参与了肺癌的发生发展过程。     

非小细胞肺癌MEST基因的表达及印迹状态

目的探讨中胚叶特异性转录子(又名父源表达基因-1)(MEST)的基因印迹在非小细胞肺癌发生发展中的作用。方法利用聚合酶链反应(PCR)技术结合限制性片段长度多态性(PFLP)技术,分析32例非小细胞肺癌及其对应的癌周正常肺组织中MEST基因的表达及其印迹状态。结果 11例MEST杂合子信息样本中,9例(81.8%)肺癌组织发生了印记缺失(LOI),其中6例为低等级、低发展阶段的肿瘤,而与之对应的癌周组织除1例为弱的双等位基因表达之外,均为单等位基因表达。同时11份MEST杂合子信息样本肺癌组织中MEST的平均表达水平是癌旁组织的1.5倍,且二者表达量差异有显著性(P0.01)。结论 MEST基因的印迹缺失参与了非小细胞肺癌的发生发展过程。     

人肝癌胰岛素样生长因子2基因的表达和印迹状态的改变

目的 研究人肝细胞性肝癌(HCC)的发生与胰岛素样生长因子2(IGF2)的表达及其印迹变化之间的关系。方法 采用RT-PCR半定量法和限制性酶切片断长度多态性分析法(RFLP),对40例HCC组织标本(其中33例有癌旁组织),检测IGF2的相对表达量,观察肝癌组织中IGF2基因印迹状态的改变。结果 HCC中IGF2的相对表达量,在各病例间的变化较大;癌组织中的表达(1.5431±1.4316)明显高于癌旁肝组织(0.6517±0.6666),t=3.695,P<0.001;癌组织和癌旁组织均有病例发生基因印迹丢失(LOI)。结论 HCC的发生与IGF2的异常表达增高有关;IGF2的LOI可能是HCC的癌前表现之一。     

肺癌前病变、肺癌中FHIT基因表达的临床研究

背景与目的FHIT基因为近年发现的新候选抑癌基因，位于3P14．2跨越FRA3B易脆点，在包括肺癌在内的人类多种肿瘤中均存在异常表达。本研究旨在观察FHIT基因在人肺癌前病变、肺癌中表达情况，探讨FHIT基因在人肺癌发生、发展过程中的可能作用。方法采用免疫组化方法检测298例甲醛固定、石蜡包埋的标本（包括161例肺癌、51例肺癌前病变、30例正常肺组织、23例肺良性病变和33例肺癌转移淋巴结）中FHIT蛋白表达情况。结果FHIT蛋白在正常肺组织及肺良性病变组织中均无失表达；癌前病变组织及肺癌组织中失表达率分别为54．9％（28／51）和59．0％（95／161）：肺癌转移淋巴结组织中FHIT蛋白失表达率78．8％（26／33），各组问比较有显著性差异（P〈0．05）。肺癌组织中FHIT基因表达水平与肺癌组织学类型、肿瘤细胞分化程度、患者P-TNM分期、淋巴结转移程度存在相关性（P〈0．05）。FHIT蛋白失表达组肺癌患者的术后五年生存率显著低于表达组（P〈0．01）。吸烟组患者FHIT基因失表达率69．1％（94／136）显著高于无吸烟组49．5％（49／99）（P〈0．01）。结论FHIT蛋白失表达可能是肺癌发生过程中的早期分子事件，与肺癌的发生、发展及预后有关；吸烟导致FHIT蛋白表达下降可能是诱发肺癌的原因之一。     

胰岛素样生长因子Ⅱ基因印迹丢失在结直肠腺瘤中的意义

背景：胰岛素样生长因子Ⅱ（IGF-Ⅱ）可促进多种细胞增殖,抑制细胞凋亡,其表达受基因印迹调控,IGF-Ⅱ基因印迹丢失（LOI）与多种肿瘤的发生相关。目前较少见IGF-Ⅱ与结直肠腺瘤关系的研究报道。目的：分析结直肠腺瘤中IGF-Ⅱ的表达及其基因印迹状态,初步探讨两者在结直肠腺瘤发生、发展中的作用。方法：以免疫组化方法检测14例正常结直肠黏膜、12例增生性息肉和53例结直肠腺瘤组织中IGF-Ⅱ的表达,以聚合酶链反应（PCR）-限制性片段长度多态性（RFLP）方法分析IGF-Ⅱ基因印迹状态。结果：IGF—Ⅱ的表达主要定位于细胞质,其表达在正常结直肠黏膜、增生性息肉和腺瘤组织中逐级递增（P＜0．05）。正常黏膜、增生性息肉和腺瘤组织的IGF—Ⅱ杂合子基因型比例分别为42．9％、41．7％和60．4％。杂合子标本中,腺瘤组织的IGF-ⅡLOI发生率显著高于正常黏膜和增生性息肉（68．8％对16．7％和20．0％,P＜0．05）。结论：IGF-Ⅱ LOI可能是导致IGF—Ⅱ蛋白表达增加,促进结直肠腺瘤发生以及向腺癌演变的重要机制。     

肺癌组织中RKIP基因启动子区甲基化状态观察

目的观察肺癌组织中Raf激酶抑制蛋白（RKIP）基因启动子区甲基化状态变化,探讨其与肺癌临床病理特征的关系。方法采用RT-PCR和甲基化特异性PCR法（MSP）分析肺癌及相应癌旁肺组织中RKIP基因表达情况及其启动子区甲基化状态。结果肺癌组织中RKIP基因启动子区甲基化率为45．8％（27／56）,明显高于癌旁肺组织的13．3％（2／56）,P〈0．05。所有甲基化的肺癌组织中RKIP基因均无表达。有淋巴结转移的43例肺癌组织中,27例RKIP基因启动子甲基化;无淋巴结转移的40例中,11例RKIP基因启动子甲基化（P〈0．05）。结论肺癌组织中RKIP基因失表达与其启动子区甲基化有关,这可能是肺癌发生发展以及转移的原因之一。     

p73基因mRNA表达与老年人肺癌临床病理学特征及预后关系的探讨

目的 探讨p73基因与老年人肺癌发生、发展的关系。方法 采用逆转录多聚酶链反应（RT-PCR）检测65例老年人肺癌组织中p73基因mRNA的表达，并与癌旁组织和正常肺组织对比，结合肺癌的临床病理学特征及预后进行分析；同时采用聚合酶链反应-单链构象多态性分析（PCR-SSCP）技术检测肺癌与癌旁组织中p73基因的突变情况。结果 老年人肺癌组织中p73基因mRNA阳性表达率（78．5％）明显高于癌旁组织（18．5％）和正常肺组织（12．3％）（P〈0．05）；不同年龄组、不同类型和不同分化程度肺癌组织中p73基因mRNA的阳性表达率差异无显著性（P〉0．05）；Ⅰ期和Ⅱ期老年人肺癌组织中p73基因mRNA阳性表达率（90．7％）明显高于Ⅲ期和Ⅳ期（54．5％）（P〈0．05）；生存3年或以上的老年人肺癌组织中p73基因mRNA阳性表达率（91．7％）明显高于生存3年以下者（68．0％）（P〈0．05）。结论 p73基因表达可能参与了调控老年人肺癌发生的过程，但并不能阻止肺癌的进展，可能不是主要的抑癌基因；基因突变不是p73参与肺癌发生发展的主要形式；p73基因表达在各型肺癌发生、发展中可能具有普遍意义，可作为判断老年人肺癌生物学行为和预后的一个参考指标。     

PTEN基因在非小细胞肺癌中表达的临床研究

目的研究PTEN基因在人非小细胞肺癌中表达情况，探讨PTEN基因在人肺癌发生、发展过程中的可能作用。方法采用免疫组化方法检测143例非小细胞肺癌、20例正常肺组织及良性病变中PTEN蛋白表达情况。结果在正常肺组织及肺良性病变组织中无失表达：肺癌组织中失表达率57．34％（82／143），两者比较有显著性差异（P〈0．001）；肺癌组织中PTEN基因表达水平与肿瘤细胞分化程度、TNM分期、淋巴结转移程度存在相关性（P〈0．001）；PTEN蛋白失表达组．肺癌患者的术后五年生存率显著低于表达组（P〈0．001）；吸烟组患者PTEN基因失表达率显著高于无吸烟组（P〈0．001）。结论PTEN蛋白失表达与肺癌的发生、发展及预后有关；多因素分析PTEN基因失表达是影响非小细胞肺癌预后的独立因素。     

survivin基因在非小细胞肺癌中的表达及与P53、c-myc、k-ras蛋白表达的关系

目的：探讨survivin基因在非小细胞肺癌（NSCLC）中的表达,及与P53、c-myc、k-ras蛋白表达的相互关系。方法：逆转录PCR法检测了76例NSCLC肿瘤组织,20例良性瘤样病变和21例病灶旁正常肺组织survivin mRNA表达,免疫组织化学法检测P53,c-myc,k-ras蛋白表达,并将结果进行了相关分析。结果：61％NSCLC癌组织表达survivin mRNA基因,而良性瘤样病变和正常组织则分别为30％和19％（P＜0．001）。survivin基因表达与肺癌组织细胞类型,分化程度,TNM分期及淋巴结转移无明显相关关系。P53蛋白,c-myc与survivin基因表达显著相关,k-ras蛋白表达与survivin基因表达未见明显相关。结论：（1）survivin基因在肺癌组织中表达上调,提示该基因对NSCLC发生发展起重要作用。Survivin基因有望成为肺癌基因治疗的新靶点。（2）抑癌基因P53的失活和癌基因c-myc的上调与survivin基因的表达可能在NSCLC癌变中起协同作用。survivin和k-ras基因则可能通过各自不同的机制参与NSCLC的发病机制。     

肺癌CDKN2基因产物表达的研究

目的观察ＣＤＫＮ２基因产物（Ｐ１６蛋白）在肺癌和癌旁正常组织的表达情况，了解该基因与肺癌的关系。方法采用ＳＰ免疫组织化学方法观察ＣＤＫＮ２基因产物在１３９例肺癌组织的表达情况，并与癌旁正常组织进行对比。结果Ｐ１６蛋白在良、恶性细胞的胞浆中均有表达，癌旁正常支气管粘膜上皮和浆液腺Ｐ１６蛋白的阳性率高于癌组织（Ｐ＜０．０１）。肺癌组织中Ｐ１６蛋白的总阳性率为６１．９％，腺癌的阳性率高于鳞癌和小细胞癌（Ｐ＜０．０１）。在鳞癌和腺癌Ｐ１６蛋白的阳性率随着分化程度的降低而下降，高分化和低分化腺癌之间Ｐ１６阳性率的差异有显著性（Ｐ＜０．０５）。结论Ｐ１６蛋白表达缺失与肺癌的发生有关，且随着分化程度的下降表达缺失增加。     

Biased learning affects mate choice in a butterfly

Early acquisition of mate preferences or mate-preference learning is associated with signal diversity and speciation in a wide variety of animal species. However, the diversity of mechanisms of mate-preference learning across taxa remains poorly understood. Using the butterfly Bicyclus anynana we uncover a mechanism that can lead to directional sexual selection via mate-preference learning: a bias in learning enhanced ornamentation, which is independent of preexisting mating biases. Naïve females mated preferentially with wild-type males over males with enhanced wing ornamentation, but females briefly exposed to enhanced males mated significantly more often with enhanced males. In contrast, females exposed to males with reduced wing ornamentation did not learn to prefer drab males. Thus, we observe both a learned change of a preexisting mating bias, and a bias in ability to learn enhanced male ornaments over reduced ornaments. Our findings demonstrate that females are able to change their preferences in response to a single social event, and suggest a role for biased learning in the evolution of visual sexual ornamentation.     

Hereditary paraganglioma

Head and neck paraganglioma is a rare tumour, especially in its familial form. We report a case of a multifocal head and neck paraganglioma in a young man with a family history of cervical tumours. At the age of 24, exploration of a left cervical swelling disclosed jugulotympanic and carotid body paragangliomas. Surgical removal of both tumours was performed. Two years later, a right carotid body as well as vagal paragangliomas were discovered. Follow-up at age 30 demonstrated relapse of the bilateral cervical paragangliomas, but also aortopulmonary and mesogastric paragangliomas. Cervical paragangliomas were also detected in the patient's sister and daughter, but not in his father. Furthermore, the proband's paternal grandmother and a maternal great-uncle had a history of 'neck scar'. This family history is suggestive of an autosomal dominant pattern of inheritance with maternal genomic imprinting. Genetic analysis of paraganglioma kindreds showed linkage with two different loci: 11q13.1 and 11q22.3-q23. Further knowledge of the genes involved could provide early diagnosis and accurate genetic counselling in affected families. Thorough familial investigation is consequently mandatory in all head and neck paragangliomas, especially in younger patients with multiple localizations, as surgical removal is safer at an early stage.     

Core-Shell Imprinted Particles for Adenovirus Binding

Virus-imprinted polymers were synthesized via surface imprinting strategies to produce core-shell imprinted particles selective for human adenovirus type 5. High binding affinity of the target virus towards the resulting imprinted layer was confirmed and unspecific binding was reduced in presence of blocking agents, i.e., via bovine serum albumin and skim milk in combination with Tween 20. In addition, the imprinted materials were applied for adenovirus extraction from cell culture supernatants. High levels of virus binding with negligible binding of matrix proteins confirmed the suitability of these materials for binding and extraction of the target virus from complex matrices.     

Neuregulin 1-HER axis as a key mediator of hyperglycemic memory effects in breast cancer

Poor outcomes in diabetic patients are observed across a range of human tumors, suggesting that cancer cells develop unique characteristics under diabetic conditions. Cancer cells exposed to hyperglycemic insults acquire permanent aggressive traits of tumor growth, even after a return to euglycemic conditions. Comparative genome-wide mapping of hyperglycemia-specific open chromatin regions and concomitant mRNA expression profiling revealed that the neuregulin-1 gene, encoding an established endogenous ligand for the HER3 receptor, is activated through a putative distal enhancer. Our findings highlight the targeted inhibition of NRG1-HER3 pathways as a potential target for the treatment breast cancer patients with associated diabetes.     

Shape selection of twist-nematic-elastomer ribbons

How microscopic chirality is reflected in macroscopic scale to form various chiral shapes, such as straight helicoids and spiral ribbons, and how the degree of macroscopic chirality can be controlled are a focus of studies on the shape formation of many biomaterials and supramolecular systems. This article investigates both experimentally and theoretically how the chiral arrangement of liquid crystal mesogens in twist-nematic-elastomer films induces the formation of helicoids and spiral ribbons because of the coupling between the liquid crystalline order and the elasticity. It is also shown that the pitch of the formed ribbons can be tuned by temperature variation. The results of this study will facilitate the understanding of physics for the shape formation of chiral materials and the designing of new structures on basis of microscopic chirality.     

Placental protection of the fetal brain during short-term food deprivation

The fetal genome regulates maternal physiology and behavior via its placenta, which produces hormones that act on the maternal hypothalamus. At the same time, the fetus itself develops a hypothalamus. In this study we show that many of the genes that regulate placental development also regulate the developing hypothalamus, and in mouse the coexpression of these genes is particularly high on embryonic days 12 and 13 (days E12-13). Such synchronized expression is regulated, in part, by the maternally imprinted gene, paternally expressed gene 3 (Peg3), which also is developmentally coexpressed in the hypothalamus and placenta at days E12-13. We further show that challenging this genomic linkage of hypothalamus and placenta with 24-h food deprivation results in disruption to coexpressed genes, primarily by affecting placental gene expression. Food deprivation also produces a significant decrease in Peg3 gene expression in the placenta, with consequences similar to many of the placental gene changes induced by Peg3 mutation. Such genomic dysregulation does not occur in the hypothalamus, where Peg3 expression increases with food deprivation. Thus, changes in gene expression brought about by food deprivation are consistent with the fetal genome's maintaining hypothalamic development at a cost to its placenta. This biased change to gene dysregulation in the placenta is linked to autophagy and ribosomal turnover, which sustain, in the short term, nutrient supply for the developing hypothalamus. Thus, the fetus controls its own destiny in times of acute starvation by short-term sacrifice of the placenta to preserve brain development.     

Genomic landscape of human allele-specific DNA methylation

DNA methylation mediates imprinted gene expression by passing an epigenomic state across generations and differentially marking specific regulatory regions on maternal and paternal alleles. Imprinting has been tied to the evolution of the placenta in mammals and defects of imprinting have been associated with human diseases. Although recent advances in genome sequencing have revolutionized the study of DNA methylation, existing methylome data remain largely untapped in the study of imprinting. We present a statistical model to describe allele-specific methylation (ASM) in data from high-throughput short-read bisulfite sequencing. Simulation results indicate technical specifications of existing methylome data, such as read length and coverage, are sufficient for full-genome ASM profiling based on our model. We used our model to analyze methylomes for a diverse set of human cell types, including cultured and uncultured differentiated cells, embryonic stem cells and induced pluripotent stem cells. Regions of ASM identified most consistently across methylomes are tightly connected with known imprinted genes and precisely delineate the boundaries of several known imprinting control regions. Predicted regions of ASM common to multiple cell types frequently mark noncoding RNA promoters and represent promising starting points for targeted validation. More generally, our model provides the analytical complement to cutting-edge experimental technologies for surveying ASM in specific cell types and across species.