SEMA3B基因在鼻咽癌组织中的表达、杂合性丢失和甲基化分析

SEMA3B基因定位于鼻咽癌高频缺失区域3p21.3上,最近被证明具有抑瘤基因的功能.分析了鼻咽癌组织中SEMA3B基因的表达、杂合性丢失(LOH)和甲基化情况.首先应用逆转录-聚合酶链式反应(RT-PCR)方法检测了33例鼻咽癌组织和15例慢性鼻咽炎组织中SEMA3B基因的表达,结果显示75.8%(25/33)鼻咽癌组织中SEMA3B基因表达缺失或下调,显著低于慢性鼻咽炎组织中的表达(P=0.001).进一步选取3个微卫星位点D3S1568、D3S1621和D3S4597分析了20例鼻咽癌组织中SEMA3B基因LOH的情况,结果表明3个位点的丢失率分别为10%、20%和15%,总的丢失率为45%,统计分析发现LOH与基因表达之间存在明显相关(P=0.023).最后,采用甲基化特异性PCR方法分析了SEMA3B基因启动子区甲基化,结果发现在100%的鼻咽癌组织和73.3%的慢性鼻咽炎组织中检测到SEMA3B基因启动子区高甲基化.由此得出结论,SEMA3B基因在鼻咽癌组织中表达缺失或下调,LOH是引起其表达异常的原因之一.     

The Influence of LepR Tyrosine Site Mutations on Mouse Ovary Development and Related Gene Expression Changes

Leptin exerts many biological functions, such as in metabolism and reproduction, through binding to and activating the leptin receptor, LepRb, which is expressed in many regions of the brain. To better understand the roles of LepR downstream signaling pathways, Y123F mice, which expressed mutant leptin receptors with phenylalanine (F) substituted for three tyrosines (Y) (Tyr985, Tyr1077 and Tyr1138), were generated. The body weight and abdominal fat deposits of Y123F homozygous mice (HOM) were higher than those of wild-type mice (WT). HOM ovaries were atrophic and the follicles developed abnormally; however, the HOM ovaries did not exhibit polycystic phenotypes. Moreover, Y123F HOM adults had no estrous cycle and the blood estrogen concentration remained stable at a low level below detection limit of 5 pg/ml. LepR expression in HOM ovaries was higher than in WT ovaries. Using cDNA Microarrays, the mRNA expressions of 41 genes were increased, and 100 were decreased in HOM vs. WT ovaries, and many signaling pathways were evaluated to be involved significantly. The expressions of 19 genes were validated by real-time quantitative PCR, most of which were consistent with the microarray results. Thus, Y123F HOM mice were suggested as a new animal model of PCOS for research that mainly emphasizes metabolic disorders and anovulation, but not the polycystic phenotype. Meanwhile, using the model, we found that JAK-STAT and hormone biosynthesis pathways were involved in the follicular development and ovulation disorders caused by LepR deficiency in ovaries, although we could not exclude indirect actions from the brain.     

Loss of RhoB Expression Enhances the Myelodysplastic Phenotype of Mammalian Diaphanous-Related Formin mDia1 Knockout Mice

Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis and hyperplastic bone marrow. Complete loss or interstitial deletions of the long arm of chromosome 5 occur frequently in MDS. One candidate tumor suppressor on 5q is the mammalian Diaphanous (mDia)-related formin mDia1, encoded by DIAPH1 (5q31.3). mDia-family formins act as effectors for Rho-family small GTP-binding proteins including RhoB, which has also been shown to possess tumor suppressor activity. Mice lacking the Drf1 gene that encodes mDia1 develop age-dependent myelodysplastic features. We crossed mDia1 and RhoB knockout mice to test whether the additional loss of RhoB expression would compound the myelodysplastic phenotype. Drf1 ^−/− RhoB ^−/− mice are fertile and develop normally. Relative to age-matched Drf1 ^−/− RhoB ^+/− mice, the age of myelodysplasia onset was earlier in Drf1 ^−/− RhoB ^−/− animals—including abnormally shaped erythrocytes, splenomegaly, and extramedullary hematopoiesis. In addition, we observed a statistically significant increase in the number of activated monocytes/macrophages in both the spleen and bone marrow of Drf1 ^−/− RhoB ^−/− mice relative to Drf1 ^−/− RhoB ^+/− mice. These data suggest a role for RhoB-regulated mDia1 in the regulation of hematopoietic progenitor cells.     

Diversity of Gene Expression in Hepatocellular Carcinoma Cells

Understanding tumor diversity has been a long-lasting and challenging question for researchers in the field of cancer heterogeneity or tumor evolution. Studies have reported that compared to normal cells, there is a higher genetic diversity in tumor cells, while higher genetic diversity is associated with higher progression risks of tumor. We thus hypothesized that tumor diversity also holds true at the gene expression level. To test this hypothesis, we used t-test to compare the means of Simpson's diversity index for gene expression(SDIG) between tumor and non-tumor samples.We found that the mean SDIG in tumor tissues is significantly higher than that in the non-tumor or normal tissues(P 0.05) for most datasets. We also combined microarrays and next-generation sequencing data for validation. This cross-platform and cross-experimental validation greatly increased the reliability of our results.     

HBV－NC1株X基因在真核细胞中表达，基因调控与致癌作用的初探

报道了ＨＢＶ－ＮＣ１株的Ｘ基因进入真核细胞表达载体ｐＸＴ１质粒的ＴＫ启动子之后,转染细胞及表达Ｘ基因成功。即发现包装病毒感染ＮＩＨ／３Ｔ３细胞后有Ｘ基因表达,用斑点杂交又证明此Ｘ基因已整合到细胞的基因组中,当与有ｐＭＳＨ报告基因的质粒共同感染真核细胞后确有激活转录调控现象出现。应用反义的ＸＲＮＡ表达载体感染肝癌细胞发现有接触抑制作用出现。     

抑制素亚基基因在哺乳类动物卵巢的表达与调控的研究进展

抑制素是由二硫键连接的α和β两个不同亚单位所构成的糖蛋白,它具有抑制卵泡刺激素（ＦＳＨ）的合成和分泌的作用。β亚单位借助二硫键尚可形成β亚单位二聚体－激活素,它则具有刺激ＦＳＨ分泌的作用。本文介绍了抑制素亚基ｃＤＮＡ的克隆及抑制素亚基基因在哺乳类卵巢表达与调控的研究进展,并指出在研究抑制基因表达时应予注意的问题。     

Expression of RhoB in the developing Xenopus laevis embryo

Rho GTPases are signaling components that participate to the control of cell morphology, adhesion and motility through the regulation of F-actin cytoskeleton dynamics. In this paper, we report the identification of RhoB in Xenopus laevis (XRhoB) and its expression pattern during early development. Whole-mount in situ hybridization analysis indicated that XrhoB is expressed at high levels in the dorsal marginal zone early in gastrula and in the dorsal midline at later stages. At mid-neurula stages, XrhoB expression extends to the central nervous system, presomitic mesoderm and somites. Later during development, rhoB mRNA is detected in the eyes, the migrating neural crest cells as well as the dorso-lateral part of the somites.     

PTEN基因和P53基因在子宫内膜癌中的表达及意义

目的：探讨PTEN基因和P53基因在子宫内膜癌中的表达及临床意义,为子宫内膜癌的治疗提供参考依据。方法：用免疫组化法检测50例子宫内膜癌患者PTEN基因缺失和P53基因突变情况,并分析两者与子宫内膜癌不同病理变化的相关性。结果：PTEN缺失24例,缺失率48.00%,进一步研究显示PTEN缺失与细胞分化程度和肌层浸润情况密切相关（P〈0.05）,P53突变32例,缺失率64.00%,并进一步研究显示P53突变与FIGO分期,细胞分化程度和肌层浸润情况密切相关（P〈0.05）。结论：PTEN基因缺失和P53基因突变与子宫内膜癌发生和发展密切相关,以PTEN基因和P53基因为靶点的生物治疗在进展期内膜癌中的治疗价值值得进一步深入研究。     

PTEN基因和P53基因在子宫内膜癌中的表达及意义

目的:探讨PTEN基因和P53基因在子宫内膜癌中的表达及临床意义,为子宫内膜癌的治疗提供参考依据。方法:用免疫组化法检测50例子宫内膜癌患者PTEN基因缺失和P53基因突变情况,并分析两者与子宫内膜癌不同病理变化的相关性。结果:PTEN缺失24例,缺失率48.00%,进一步研究显示PTEN缺失与细胞分化程度和肌层浸润情况密切相关(P0.05),P53突变32例,缺失率64.00%,并进一步研究显示P53突变与FIGO分期,细胞分化程度和肌层浸润情况密切相关(P0.05)。结论:PTEN基因缺失和P53基因突变与子宫内膜癌发生和发展密切相关,以PTEN基因和P53基因为靶点的生物治疗在进展期内膜癌中的治疗价值值得进一步深入研究。     

用组织微阵列技术分析鼻咽癌变多阶段组织细胞周期蛋白D1过表达

为了探讨细胞周期蛋白D1(Cyclin D1)在鼻咽癌变多阶段病变组织中的蛋白质表达与鼻咽癌变的关系,应用组织微阵列(tissue microarray)技术,采用免疫组化方法检测Cyclin D1在鼻咽癌旁粘膜上皮单纯性增生/化生(simple hyperplasia/ metaplasia,SH/SM)、异型增生/化生(atypical hyperplasia/metaplasia,AH/AM)和鼻咽癌(nasopharyngeal carcinoma,NPC)的蛋白质表达,阳性表达率分别为30.0%(3/10)、90.0%(18/20)和62.9%(39/62),其中在异型增生/化生中呈"一过性增高".表明Cyclin D1高表达可能为鼻咽癌发生过程中的早期事件;异型增生/化生可能是鼻咽癌变的重要"关卡".     

喉癌STK15基因表达和染色体不稳定的研究

为研究喉鳞状细胞癌中STK15基因表达及其与染色体不稳定的相关性,提取50例喉鳞状细胞癌及配对癌旁正常组织和喉鳞状细胞癌Hep-2细胞系的RNA,反转录合成cDNA,以β-actin为内对照进行PCR扩增,用软件分析电泳结果,研究喉癌中STK15基因表达的水平;以Hep-2细胞系为代表应用常规和高分辨G显带方法进行核型分析。在50例喉癌中,癌组织STK15表达高于配对癌旁正常组织的有34例,占68％,经统计学分析,肿瘤组与对照组差异显著,Hep-2细胞系中STK15基因表达高于内对照β-actin;Hep-2细胞系中存在显著的染色体不稳定,染色体数目变化于43－84条之间,众数为69－74条,结构畸变主要表现为13条标记染色体,本研究首次发现STK15基因在喉癌中表达增高,它可能通过中心体异常而引起染色体不稳定,在喉癌的发生,发展中发挥一定作用。     

Expression Profile of the REG Gene Family in Colorectal Carcinoma

Regenerating (REG) gene family belongs to the calcium-dependent lectin gene superfamily and encodes small multifunctional secretory proteins, which might be involved in cell proliferation, differentiation, and carcinogenesis. To clarify REG expression profile in colorectal carcinoma (CRC), the authors examined the expression of REG Iα, Iβ, III, HIP/PAP, and REG IV by immunohistochemistry on tissue microarray. The expression of REG Iα, III, and HIP/PAP was more frequently observed in the CRCs than adjacent non-neoplastic mucosa (p < 0.001), whereas it was the converse for REG Iβ and IV (p < 0.001). The expression of REG Iα, Iβ, III, and HIP/PAP was negatively correlated with the depth of invasion of CRCs (p < 0.05). The REG Iβ and HIP/PAP were less expressed in CRCs with than without venous invasion (p < 0.05). The positive rates of REG Iα and HIP/PAP were significantly higher in CRCs without than with lymph node metastasis (p < 0.05). Mucinous carcinoma more frequently expressed REG IV protein than well- and moderately differentiated ones (p < 0.05). There was a positive relationship between REG Iα, Iβ, III, and HIP/PAP expression (p < 0.05). Survival analysis indicated the REG Iβ or HIP/PAP expression was positively linked to favorable prognosis of carcinoma patients (p < 0.05). This study indicated that aberrant REG expression might be closely linked to the pathogenesis, invasion, or lymph node metastasis of CRCs. REG Iβ and HIP/PAP could be considered reliable markers of favorable prognosis of CRC patients.     

Gene Systems Network Inferred from Expression Profiles in Hepatocellular Carcinogenesis by Graphical Gaussian Model

Hepatocellular carcinoma (HCC) in a liver with advanced-stage chronic hepatitis C (CHC) is induced by hepatitis C virus, which chronically infects about 170 million people worldwide. To elucidate the associations between gene groups in hepatocellular carcinogenesis, we analyzed the profiles of the genes characteristically expressed in the CHC and HCC cell stages by a statistical method for inferring the network between gene systems based on the graphical Gaussian model. A systematic evaluation of the inferred network in terms of the biological knowledge revealed that the inferred network was strongly involved in the known gene-gene interactions with high significance Open image in new window , and that the clusters characterized by different cancer-related responses were associated with those of the gene groups related to metabolic pathways and morphological events. Although some relationships in the network remain to be interpreted, the analyses revealed a snapshot of the orchestrated expression of cancer-related groups and some pathways related with metabolisms and morphological events in hepatocellular carcinogenesis, and thus provide possible clues on the disease mechanism and insights that address the gap between molecular and clinical assessments.     

The Luteinizing Hormone Surge Regulates Circadian Clock Gene Expression in the Chicken Ovary

The molecular circadian clock mechanism is highly conserved between mammalian and avian species. Avian circadian timing is regulated at multiple oscillatory sites, including the retina, pineal, and hypothalamic suprachiasmatic nucleus (SCN). Based on the authors’ previous studies on the rat ovary, it was hypothesized that ovarian clock timing is regulated by the luteinizing hormone (LH) surge. The authors used the chicken as a model to test this hypothesis, because the timing of the endogenous LH surge is accurately predicted from the time of oviposition. Therefore, tissues can be removed before and after the LH surge, allowing one to determine the effect of LH on specific clock genes. The authors first examined the 24-h expression patterns of the avian circadian clock genes of Bmal1, Cry1, and Per2 in primary oscillatory tissues (hypothalamus and pineal) as well as peripheral tissues (liver and ovary). Second, the authors determined changes in clock gene expression after the endogenous LH surge. Clock genes were rhythmically expressed in each tissue, but LH influenced expression of these clock genes only in the ovary. The data suggest that expression of ovarian circadian clock genes may be influenced by the LH surge in vivo and directly by LH in cultured granulosa cells. LH induced rhythmic expression of Per1 and Bmal1 in arrhythmic, cultured granulosa cells. Furthermore, LH altered the phase and amplitude of clock gene rhythms in serum-shocked granulosa cells. Thus, the LH surge may be a mechanistic link for communicating circadian timing information from the central pacemaker to the ovary. (Author correspondence: stischkau@siumed.edu)     

Inhibitory Mechanism of FAT4 Gene Expression in Response to Actin Dynamics during Src-Induced Carcinogenesis

Oncogenic transformation is characterized by morphological changes resulting from alterations in actin dynamics and adhesive activities. Emerging evidence suggests that the protocadherin FAT4 acts as a tumor suppressor in humans, and reduced FAT4 gene expression has been reported in breast and lung cancers and melanoma. However, the mechanism controlling FAT4 gene expression is poorly understood. In this study, we show that transient activation of the Src oncoprotein represses FAT4 mRNA expression through actin depolymerization in the immortalized normal human mammary epithelial cell line MCF-10A. Src activation causes actin depolymerization via the MEK/Erk/Cofilin cascade. The MEK inhibitor U0126 blocks the inhibitory effect of Src on FAT4 mRNA expression and Src-induced actin depolymerization. To determine whether actin dynamics act on the regulation of FAT4 mRNA expression, we treated MCF-10A cells with the ROCK inhibitor Y-27632. Y-27632 treatment decreased FAT4 mRNA expression. This suppressive effect was blocked by siRNA-mediated knockdown of Cofilin1. Furthermore, simultaneous administration of Latrunculin A (an actin depolymerizing agent), Y-27632, and Cofilin1 siRNA to the cells resulted in a marked reduction of FAT4 mRNA expression. Intriguingly, we also found that FAT4 mRNA expression was reduced under both low cell density and low stiffness conditions, which suggests that mechanotransduction affects FAT4 mRNA expression. Additionally, we show that siRNA-mediated FAT4 knockdown induced the activity of the Hippo effector YAP/TAZ in MCF-10A cells. Taken together, our results reveal a novel inhibitory mechanism of FAT4 gene expression through actin depolymerization during Src-induced carcinogenesis in human breast cells.     

RhoB/ROCK 蛋白分子在重度子痫前期的表达

目的:探讨RhoB/ROCK蛋白分子在重度子痫前期(severe preeclampsia,sPE)患者胎盘组织中表达水平以及意义。方法:取sPE产妇和正常产妇胎盘组织各20例,通过Western blot和免疫组化检测胎盘组织中Rho亚家族蛋白(RhoB、RhoC)及其Rho激酶即ROCK(ROCKI、ROCKII)蛋白的表达水平,应用Spearman等级相关分析法检验RhoB、RhoC与ROCKI、ROCKII蛋白表达水平的相关性。结果:RhoB、ROCKI、ROCKII蛋白在sPE表达水平增加(P<0.05);sPE患者胎盘组织中RhoB与ROCKI、ROCKII蛋白表达水平均呈正相关(r=0.793,r=0.901,P<0.05)。结论:RhoB及其与下游分子ROCKI、ROCKII构成的信号通路,在sPE的发病中可能发挥着重要的作用。