Chromosome 17 deletions and p53 gene mutations in colorectal carcinomas

Previous studies have demonstrated that allelic deletions of the short arm of chromosome 17 occur in over 75% of colorectal carcinomas. Twenty chromosome 17p markers were used to localize the common region of deletion in these tumors to a region contained within bands 17p12 to 17p13.3. This region contains the gene for the transformation-associated protein p53. Southern and Northern blot hybridization experiments provided no evidence for gross alterations of the p53 gene or surrounding sequences. As a more rigorous test of the possibility that p53 was a target of the deletions, the p53 coding regions from two tumors were analyzed; these two tumors, like most colorectal carcinomas, had allelic deletions of chromosome 17p and expressed considerable amounts of p53 messenger RNA from the remaining allele. The remaining p53 allele was mutated in both tumors, with an alanine substituted for valine at codon 143 of one tumor and a histidine substituted for arginine at codon 175 of the second tumor. Both mutations occurred in a highly conserved region of the p53 gene that was previously found to be mutated in murine p53 oncogenes. The data suggest that p53 gene mutations may be involved in colorectal neoplasia, perhaps through inactivation of a tumor suppressor function of the wild-type p53 gene.     

Identification of p53 gene mutations in bladder cancers and urine samples

Although bladder cancers are very common, little is known about their molecular pathogenesis. In this study, invasive bladder cancers were evaluated for the presence of gene mutations in the p53 suppressor gene. Of 18 tumors evaluated, 11 (61 percent) were found to have genetic alterations of p53. The alterations included ten point mutations resulting in single amino acid substitutions, and one 24-base pair deletion. In all but one case, the mutations were associated with chromosome 17p allelic deletions, leaving the cells with only mutant forms of the p53 gene products. Through the use of the polymerase chain reaction and oligomer-specific hybridization, p53 mutations were identified in 1 to 7 percent of the cells within the urine sediment of each of three patients tested. The p53 mutations are the first genetic alterations demonstrated to occur in a high proportion of primary invasive bladder cancers. Detection of such mutations ex vivo has clinical implications for monitoring individuals whose tumor cells are shed extracorporeally.     

p53、C-erbB-2、nm23基因及雌孕激素受体在乳腺癌组织中的表达及其临床意义

目的：观察雌激素受体(ER)、孕激素受体(PR)和p53、C—erbB—2、nm23基因在乳腺癌组织中的表达并探讨其临床意义。方法：应用免疫组化S—P法．对96例乳腺癌组织进行了ER、PR、p53、C—erbB—2、nm23检测，结合临床表现及随访结果作统计学分析。结果：ER、PR、p53、C—erbB-2、nm23阳性表达率分别为52.1％、47．9％、46.9％、62．5％、70.8％。浸润型乳腺癌组织C—erbB-2阳性表达明显高于非浸润型(P＜0．01)；ER、PR 、p53、nm23阳性表达与病理类型无关(P＞0．05)。有淋巴结转移组P53、C—erbB-2的阳性表达率明显高于无淋巴结转移组。有淋巴结转移组nm23的阳性表达率显著低干无淋巴结转移组。差异均有非常显著性(P＜0．01)；而ER、PR的阳性表达率与淋巴结转移与否无关(P＞0．05)。ER和(或)PR、nm23阳性组乳腺癌复发率明显低于阴性组(P＜0．05)，而p53、C—erbB—2阳性组乳腺癌复发率明显高于阴性组(P＜0．05)。结论：检测乳腺癌组织中的ER、PR及p53、C—erbB-2、nm23基因对评价乳腺癌患者的预后有重要价值。     

p53: a frequent target for genetic abnormalities in lung cancer

Allele loss is a hallmark of chromosome regions harboring recessive oncogenes. Lung cancer frequently demonstrates loss of heterozygosity on 17p. Recent evidence suggests that the p53 gene located on 17p13 has many features of such an antioncogene. The p53 gene was frequently mutated or inactivated in all types of human lung cancer. The genetic abnormalities of p53 include gross changes such as homozygous deletions and abnormally sized messenger RNAs along with a variety of point or small mutations, which map to the p53 open reading frame and change amino acid sequence in a region highly conserved between mouse and man. In addition, very low or absent expression of p53 messenger RNA in lung cancer cell lines compared to normal lung was seen. These findings, coupled with the previous demonstration of 17p allele loss in lung cancer, strongly implicate p53 as an anti-oncogene whose disruption is involved in the pathogenesis of human lung cancer.     

乳腺癌组织中MMP-9、P53的表达和微血管密度的检测及其意义

目的观察乳腺癌细胞中MMP-9、P53的表达及组织中微血管密度与患者腋淋巴结及远处肿瘤转移之间的关系,以探讨它们与乳腺癌生物学行为的关系及机制。方法通过组织化学方法检测MMP-9、P53在肿瘤细胞中的表达,在显微镜下计算肿瘤组织中微血管密度值,观察其与患者腋淋巴结及远处肿瘤转移之间的关系。结果MMP-9主要分布在胞浆,20例乳腺纤维腺瘤细胞均未表达MMP-9,乳腺癌细胞内随同侧腋淋巴结转移量的增多,MMP-9阳性级别增加(P<0.01);P53主要表现为核阳性,20例乳腺纤维腺瘤细胞中18例未表达P53,随同侧腋淋巴结转移量的增多,P53表达级别增加(P<0.01);随同侧腋淋巴结转移量的增多,微血管密度明显增加(P<0.01)。结论肿瘤细胞中MMP-9、P53蛋白的高表达及MVD值可以作为评估患者腋淋巴结转移及其它部位远处转移的重要指标。     

nm23与p53在皮肤癌中的表达及其临床意义

目的：探讨ｎｍ２３、ｐ５３在皮肤癌中的表达及其临床意义。方法；应用霉卵白素（ＳＰ）免疫组化技术对４１例皮肤癌标本染色。结果：ｎｍ２３阴性表达者肿瘤浸润深度及区域淋巴结转移率明显高于阳性表达者（Ｐ均〈０．０１）；ｐ５３阳性表达者肿瘤浸润浓度及区域淋巴结转移率明显高于阴性表达者（Ｐ均〈０．０５）。结论：ｎｍ２３基因缺失和ｐ５３基因突吕的浸润及淋巴结转移中起重要作用。     

Caenorhabditis elegans p53: role in apoptosis, meiosis, and stress resistance

We have identified a homolog of the mammalian p53 tumor suppressor protein in the nematode Caenorhabditis elegans that is expressed ubiquitously in embryos. The gene encoding this protein, cep-1, promotes DNA damage-induced apoptosis and is required for normal meiotic chromosome segregation in the germ line. Moreover, although somatic apoptosis is unaffected, cep-1 mutants show hypersensitivity to hypoxia-induced lethality and decreased longevity in response to starvation-induced stress. Overexpression of CEP-1 promotes widespread caspase-independent cell death, demonstrating the critical importance of regulating p53 function at appropriate levels. These findings show that C. elegans p53 mediates multiple stress responses in the soma, and mediates apoptosis and meiotic chromosome segregation in the germ line.     

甲状腺肿瘤中p53、bcl-2及c-myc蛋白的表达

目的 :探讨p5 3、bcl 2和c myc蛋白在甲状腺肿瘤中的表达意义。 方法 :应用免疫组化EnvisionTM法对 73例甲状腺肿瘤中 p5 3、bcl 2和c myc蛋白的表达进行检测。 结果 :3 6例腺瘤中 p5 3、bcl 2和c myc蛋白的阳性表达率分别为 :0 0 %( 0 / 3 6)、88.6%( 3 2 / 3 6)和 5 0 .0 %( 18/ 3 6) ;3 7例腺癌则分别为 :2 1.6%( 8/ 3 7)、64 .9%( 2 4/ 3 7)和 89.2 %( 3 3 / 3 7) ;p5 3、bcl 2、c myc蛋白分别在 3 6例腺瘤与 3 7例腺癌之间比较差异均有显著性 (P <0 .0 5或P <0 .0 1)。p5 3蛋白阳性表达的腺癌 8例 ,其bc1 2及c myc蛋白阳性表达率分别为 75 .0 %( 6/ 8)和 10 0 %( 8/ 8) ,在腺癌中 p5 3蛋白表达与bcl 2蛋白表达仅呈低度正相关 (r =0 .3 5 1,P <0 .0 5 )。 5例淋巴结转移性甲状腺癌中p5 3蛋白阳性表达率为 60 0 %( 3 / 5 ) ,但均无bc1 2蛋白阳性表达。结论 :p5 3、bcl 2及c myc蛋白可能共同参与甲状腺癌的发生发展 ;检测 p5 3蛋白有助于甲状腺良恶性肿瘤的鉴别     

中国肝癌病人p53突变体R248W的细胞功能研究

【目的】探索p53基因突变对细胞正常功能的影响,阐明肝癌的发病机制。【方法】利用PCR产物直接测序的方法,对202例中国肝癌患者p53基因的11个外显子进行突变筛查;利用定点突变的方法构建真核表达载体pCMV-R248W,Western blot检测突变体蛋白R248W在p53缺失型H1299细胞中的表达情况;采用双荧光素酶报告基因检测系统和流式细胞仪,研究R248W突变对转录活性及促凋亡能力的影响。【结果】在其中1例样本的7号外显子处筛查到突变形式为CGG→TGG的点突变,使p53蛋白248位的精氨酸(Arg)突变为色氨酸(Trp),即R248W,突变率为0.495%;在H1299细胞中转染等量的pCMV-p53和pCMV-R248W时,野生型p53与突变体R248W的蛋白表达量相当,但R248W的转录活性及促凋亡能力显著低于野生型p53。【结论】R248W突变可能引起p53蛋白构象的改变,从而影响p53的转录活性及促凋亡能力,使细胞的正常生理功能紊乱,导致肿瘤发生。     

益肾调肝方治疗乳腺癌患者类更年期综合征肝肾阴虚证的临床研究

目的观察益肾调肝方对乳腺癌患者类更年期综合征证候群的治疗作用及安全性。方法将60例符合入选标准的乳腺癌患者,随机分为治疗组和对照组。治疗组予益肾调肝方口服,对照组予更年安胶囊口服。比较两组病人更年期综合征症状积分、临床主症症状积分、生活质量、雌激素水平、卵泡刺激素水平以及药物不良反应等指标。结果治疗组与对照组在治疗后更年期综合征症状、临床主症、生活质量改善方面均优于治疗前(P<0.05),但治疗组效果优于对照组(P<0.05);治疗组在临床主症的改善方面以潮热汗出、烦躁易怒尤为明显,改善率分别为96.67%和93.33%;两组患者治疗前后雌激素及卵泡刺激素水平均无明显变化(P>0.05)。两组治疗前后白细胞、血小板、血红蛋白计数比较均无统计学差异(P>0.05),两组均未出现明显肝肾功能、心电图方面异常。结论益肾调肝方治疗乳腺癌合并类更年期综合征疗效肯定,无明显不良反应。 更多还原     

Expression of p53 and CD44 in Canine Breast Tumor

The p53 and CD44 expression of 10 cases in canine breast tumor were examined utilizing immunohistochemical assay with rabbit anti-mouse polyclonal antibodies against p53 or CD44, respectively. The p53 expression was significantly higher in malignant than in benign breast tumor. The expression of CD44 was not significantly different in malignant breast cancer and benign breast tumor. This suggests that p53 can be used as an indicator for animal prognosis.     

新型穿膜肽介导 p53融合蛋白的表达及其免疫原性分析

目的：原核表达新型细胞穿膜肽RDP介导p53融合蛋白,并检测其免疫原性的强弱．方法：以质粒pET28a‐p53为模板扩增p53基因,并克隆至原核表达载体pET28a‐RDP中,构建重组表达质粒pET28a‐RDP‐p53,转化至大肠杆菌Rosetta ,IPTG诱导表达蛋白并纯化,SDS‐PAGE确定该蛋白准确性．同时,将昆明小鼠分为空白对照组（等容生理盐水）和RDP‐p53融合蛋白高、中、低剂量（4 mg／kg ,2 mg／kg ,1 mg／kg）组,经腹腔注射免疫,每隔2 d给药1次,30 d后眼球取血,用酶联免疫吸附法（ELISA）测定血清中IgG的含量．结果：双酶切及测序结果显示, p53基因已克隆入表达载体中;RDP‐p53融合蛋白在上清和沉淀中均获得表达．ELISA测定结果表明,与对照组比较,低、中剂量组小鼠血清中IgG含量没有明显升高（p＞0.05）,高剂量组显著升高（p＜0.05）．结论：成功表达并纯化RD P‐p53融合蛋白,其免疫原性较弱且与给药剂量相关,为进一步研究RD P‐p53融合蛋白对脑肿瘤的药理作用奠定基础．     

Noxa, a BH3-only member of the Bcl-2 family and candidate mediator of p53-induced apoptosis

A critical function of tumor suppressor p53 is the induction of apoptosis in cells exposed to noxious stresses. We report a previously unidentified pro-apoptotic gene, Noxa. Expression of Noxa induction in primary mouse cells exposed to x-ray irradiation was dependent on p53. Noxa encodes a Bcl-2 homology 3 (BH3)-only member of the Bcl-2 family of proteins; this member contains the BH3 region but not other BH domains. When ectopically expressed, Noxa underwent BH3 motif-dependent localization to mitochondria and interacted with anti-apoptotic Bcl-2 family members, resulting in the activation of caspase-9. We also demonstrate that blocking the endogenous Noxa induction results in the suppression of apoptosis. Noxa may thus represent a mediator of p53-dependent apoptosis.     

转染抑癌基因PTEN对人乳腺癌ZR-75-1细胞的细胞周期和增殖能力的影响

目的：观察PTEN（phosphatase and tensin homology deleted on chromosome ten，第10号染色体上磷酸酶和张力蛋白同源缺失的基因）对人乳腺癌细胞ZR-75-1细胞增殖和细胞周期的影响。方法；利用脂质体介导法将携带有野生型和突变型PTEN cDNA的真核表达载体pBP—wt—PTEN和pBP—G129R—PTEN导八人乳腺癌ZR-75-1细胞（质粒转染成功后实验分为C—WT—PTEN组、CG129R—PTEN组和未转染质粒组即对照组）后，以RT—PCR、Western blot分析目的基因的表达，并采用MTT法和流式细胞术检测细胞增殖和细胞周期。结果：C—WT—PTEN组、C—G129R—PTEN组细胞PTEN mRNA及PTEN蛋白出现明显的高表达。C—WT—PTEN组细胞生长的抑制率可高达42．7％，与对照组比较．差异有显著性（P〈0．05）。但C—G129R—PTEN组细胞生长的抑制率与对照组比较，差异无显著性（P〉0．05）。流式细胞术显示C—WT—PTEN组细胞周期从G1期到S期已发生抑制。结论：野生型PTEN可依赖其磷酸酶活性抑制肿瘤细胞的增殖,并最终诱导细胞凋亡。     

MDM2和p53在大肠癌组织中的表达及其意义

目的：探讨抑癌基因mdm2、p53在大肠癌组织中表达情况及与临床病理之间的关系。方法：采用免疫组化SABC法检测大肠癌79例,大肠腺瘤样息肉34例,正常大肠粘膜组织15例中MDM2、p53的表达。结果：MDM2在正常大肠组织、大肠腺瘤、大肠癌中表达阳性率分别为6.67%（1/15）、41.18%（14/34）、63.29%（50/79）;p53阳性率分别为0、35.29%（12/34）、67.09%（53/79）。MDM2、p53在正常组织、大肠腺瘤、大肠癌组织中表达率逐渐增加（P〈0.01）,两者与DukesC期、D期及远处转移相关,与年龄、性别及组织细胞分化程度无关。MDM2与p53表达之间呈正相关。结论：MDM2、p53高表达与大肠癌的发生、发展和预后相关。     

焦作竹子种质资源调查评价及保存利用

竹子是林木种质资源不可或缺的重要内容,经调查,全市共有竹子种质资源11 属74 种 (包括种下单位),其中本地竹种7 种（特有竹种2 种）,引进品种67 种,对其焦作立地条件的生长应 用简要分析与评价,不断加大竹子种质资源的保护和开发应用力度。     

甲状腺乳头状癌p53蛋白的表达及临床意义

目的：观察p53蛋白在甲状腺乳头状癌中的表达及临床意义。方法；采用免疫组化S-P法，对68例甲状腺乳头状癌和10例正常甲状腺组织检测，用有关统计学方法结合临床及随访资料进行分析。结果：68例甲状腺乳头状癌中．p53蛋白阳性率为27．9％。正常甲状腺组织阴性。甲状腺乳头状癌病理分级、有无淋巴结转移与p53蛋白阳性表达率有关。结论：甲状腺乳头状癌预后可能与p53蛋白过度表达有关。     

玉米种质资源扩增、改良及创新方法探讨

创造并掌握丰富的种质资源是培育新的作物和优良品种的前提,我国玉米种质资源相对比较狭窄,本文结合育种实践,分析了当前应用的各种种质改良、创新方法的特点和优势,提出了它在今后玉米育种和种质扩增中存在的问题和利用的思路.     

PTEN磷酸酶活性对人乳腺癌ZR-75-1细胞的迁移及粘着斑激酶磷酸化水平的影响

目的:探讨PTEN磷酸酶活性对ZR-75-1人乳腺癌细胞迁移及粘着斑激酶磷酸化水平的影响。方法:用有和无磷酸酶活性的两种PTEN表达质粒(W t和G 129)转染人乳腺癌细胞株ZR-75-1,用人工基底膜侵袭试验检测其转染前后的迁移能力,以W estern-b lot检测未转染的ZR-75-1和两种表达质粒的ZR-75-1磷酸化粘着斑激酶水平。结果:转染后有磷酸酶活性、无磷酸酶活细胞与未转染ZR-75-1细胞间侵袭抑制率、运动抑制率差异有显著性(P<0.01)。各组细胞间总FAK(粘着斑激酶)水平无明显差异,而W T-PTEN与G 129和ZR-75-1组FAK 397位酪氨酸磷化水平有明显差异。结论:PTEN具有抑制乳腺癌细胞ZR-75-1转移的作用,其机制可能与PTEN使FAK去磷酸化有关。