Mutations of p53 gene exons 4-8 in human esophageal cancer

AIM: To characterize the tumor suppressor gene p53 mutations in exon 4, esophageal cancer and adjacent non-cancerous tissues. METHODS: We performed p53 (exons 4-8) gene mutation analysis on 24 surgically resected human esophageal cancer specimens by PCR, single-strand conformation polymorphism, and DNA sequencing. RESULTS: p53 gene mutations were detected in 9 of 22 (40.9%) esophageal cancer specimens and 10 of 17 (58.8%) adjacent non-cancerous tissues. Eight of sixteen (50.0%) point mutations detected were G-A transitions and 9 of 18 (50.0%) p53 gene mutations occurred in exon 4 in esophageal cancer specimens. Only 1 of 11 mutations detected was G-A transition and 4 of 11 (36.4%) p53 gene mutations occurred in exon 4 in adjacent non-cancerous tissues. CONCLUSION: Mutation of p53 gene in exon 4 may play an important role in development of esophageal cancer. The observation of p53 gene mutation in adjacent non-cancerous tissues suggests that p53 gene mutation may be an early event in esophageal carcinogenesis. Some clinical factors, including age, sex, pre-operation therapy and location of tumors, do not influence p53 gene mutation rates.     

Changes of serum p53 antibodies and clinical significance of radiotherapy for esophageal squamous cell carcinoma

AIM： To explore the relationship between serum p53 antibodies （p53-Abs） and clinicopathological characteristics and therapeutic effect in patients with esophageal carcinoma （EC）, and to investigate sequential changing regularity of serum pS3-Abs after radiotherapy.
METHODS： The serum pS3-Ab levels were detected in 46 EC patients and 30 healthy adults by enzyme linked immunosorbent assay （ELISA）. The blood samples were collected on the day before radiotherapy and on the administration of an irradiation dose of 20 Gy/10 f/12 d, 40 Gy/20 f/24 d and 60 Gy/30 f/36 d after radiotherapy.
RESULTS： The level and positive rate of serum pS3-Abs in EC patients were significantly higher than those in normal individuals （P 〈 0.05）. Serum anti-p53 antibodies were positive in 18 of 46 EC patients （39.1%）. The positive rate of pS3-Abs in EC was related to histological grade, disease stage and lymph node metastasis （P 〈 0.05）, but it was not significantly related to sex, age and to the size and site of tumor. The level and positive rate of p53-Abs had significant differences between before radiotherapy and after administration of an irradiation dose of 40 Gy/20 f/24 d and 60 Gy/30 f/36 d （P 〈 0.05 orP 〈 0.01）. The positive rate of p53-Abs in EC patients with effect was significantly lower than that in those without effect after radiotherapy （P 〈 0.0001）.
CONCLUSION： Detection of serum p53-Abs is helpful to the diagnosis of esophageal carcinoma. Monitoring for sequential change of serum p53-Abs before and after radiotherapy in patients with esophageal carcinoma is also useful to evaluate the response to the treatment and prognosis of the patients.     

重组人p53腺病毒感染对携带不同p53状态胃癌细胞增殖和凋亡的影响

目的研究重组人p53腺病毒感染不同p53状态胃癌细胞对其p53蛋白表达、生长抑制率、细胞周期与凋亡率的影响。方法不同浓度重组人p53腺病毒感染3种不同p53状态胃癌细胞,即含野生型p53基因的细胞(wild-type)、含突变型p53基因的细胞(mutant-type)、含空载质粒即p53基因缺失的细胞(vector-cell)。48 h后,用Western blotting法检测p53蛋白在3种胃癌细胞中的表达;用MTT法测定重组人p53腺病毒感染3种胃癌细胞的生长抑制率,用流式细胞仪检测细胞周期分布和凋亡率。结果rAd-p53感染3种胃癌细胞48 h后p53蛋白表达阳性,对照组p53基因缺失的胃癌细胞无表达,对照组含野生型p53基因的细胞和含突变型p53基因的细胞弱表达。rAd-p53对3种胃癌细胞的生长抑制效应在一定的浓度范围内呈剂量依赖性,而与细胞内在的p53状态无关。含野生型p53基因的细胞、含突变型p53基因的细胞和p53基因缺失的细胞感染rAd-p53后诱导G2/M期阻滞与细胞凋亡率分别增加2.5、3.6、3.2倍。结论腺病毒介导p53基因感染3种不同p53状态胃癌细胞改变细胞内在的p53状态,p53蛋白表达、生长抑制率、细胞周期分布、凋亡率均与细胞内在的p53状态无关。     

Association of p53/p21 expression with cigarette smoking and prognosis in esophageal squamous cell carcinoma patients

factors,such as cigarette smoking,in esophageal squamous cell carcinoma(ESCC)in northeastern Iran,a region with a high incidence of ESCC.METHODS:The expression of p53 and p21 proteins was investigated immunohistochemically in tumor tissue from 80 ESCC patients and in 60 available paraffinembedded blocks of adjacent normal specimens from the cases,along with normal esophageal tissue from 80 healthy subjects.RESULTS:Positive expression of p53 protein was detected in 56.2%(45/80)of ESCC cases,and in none of the normal esophageal tissue of the control group(P<0.001).Furthermore,73.8%(59/80)of ESCC cases and 43.8%(35/80)of controls had positive expression of p21 protein(P<0.001).Cigarette smoking was significantly associated with p53 over-expression in ESCC cases(P=0.010,OR=3.64;95%CI:1.32-10.02).p21 over-expression was associated with poorer clinical outcome among the ESCC patients(P=0.009).CONCLUSION:Over-expression of p53 in association with cigarette smoking may play a critical role in ESCC carcinogenesis among this high-risk population of northeastern Iran.Furthermore,p21 over-expression was found to be associated with poor prognosis,specifically in the operable ESCC patients.     

血清p53抗体在肺癌早期诊断中的价值

目的探讨p53抗体在肺癌诊断,尤其是早期诊断中的价值。方法应用酶联免疫吸附法（enzyme linked immunosorbent assay,ELISA）检测32例健康者、37例肺疾病患者和82例肺癌患者血清中p53抗体的水平。结果肺癌患者血清p53抗体水平显著高于肺疾病及健康者（P〈0.05）;血清p53抗体诊断肺癌的敏感性和特异性分别为29.27%及100%;血清p53抗体阳性率与肺癌病理分型及临床分期无关（P〉0.05）。结论p53抗体可作为肺癌诊断,尤其是早期诊断的新的有价值的标志物。     

抑癌基因p53及p16单独或共转染治疗非小细胞肺癌的动 …

目的 观察抑癌基因ｐ５３和ｐ１６单独或或共转染在动物整体中治疗非小细胞肺癌（ＮＳＣＬＣ）的效果。方法 采用培养细胞移植法,将２ ＮＳＣＬＣ细胞系Ａ５６９接种于裸小鼠背部皮下,建立裸小鼠皮下肺癌移植瘤模型。将２５只荷瘤裸小鼠随机分成空白对照组、十八酰基胺阳离子（ＳＡ０对照组、ｐ５３基因组、ｐ１６基因组、ｐ５３＋ｐ１６基因组,共５组,每组５只。采用瘤体内直接注射的方法,用ＳＡ脂质体介异,将ｐ５３和（或     

食管黏膜凋亡增殖和p53表达的增龄变化与食管鳞癌的关系

目的探讨食管黏膜增殖凋亡和p53表达的增龄变化以及这些变化与食管鳞癌的关系。方法按年龄分层选择连续胃镜检查对象818例,男414例,女404例。分为青中年组（258例）、老年前期组（296例）和老年组（264例）,进行食管活组织检查,应用TUNEL法检测凋亡指数（AI）,免疫组化法检测增殖指数（PI）和p53表达。结果食管正常上皮→单纯增生→轻中重度异型增生→鳞癌的发展过程中,AI等级逐渐下降,PI等级和p53表达逐渐增高。在食管正常上皮中,AI等级青中年组〉老年前期组〉老年组;PI等级比较,老年前期组分别高于青中年组和老年组（P〈0.01）;p53表达在老年前期组和老年组均高于青中年组（P〈0.01）。非条件logistic回归分析,食管鳞癌独立危险因素为增龄、PI等级和p53表达。当食管黏膜PI等级明显增高伴p53阳性时,鳞癌检出率明显增高,轻中重度异型增生有增高趋势,老年人尤为突出。结论食管黏膜正常上皮随增龄出现增殖凋亡和p53表达变化,与食管黏膜癌变过程变化相似,老年人食管黏膜PI明显增高伴p53阳性可作为食管鳞癌和癌前病变进一步随访和筛查的线索。     

Specific intronic p53 mutation in esophageal squamous cell carcinoma in Southern Thailand

AIM:To investigate p53 mutations in esophageal cancer in a high-risk population,and correlate them with smoking,alcohol consumption and betel chewing.METHODS:One hundred and sixty-five tumor samples of esophageal squamous cell carcinoma(ESCC) obtained from a university hospital in Songkhla province,Southern Thailand were investigated for p53 mutations in exons 5-8,using polymerase chain reaction-single strand conformation polymorphism analysis,followed by direct sequencing.A polymerase chain reactionrestric...     

血清p53抗体是消化系肿瘤新的标志物

目的　探讨血清p5 3抗体对消化系肿瘤的诊断价值。方法　应用ELISA法检测了食管癌、胃癌、肝癌患者血清中p5 3抗体的浓度。结果　血清p5 3抗体浓度在肿瘤患者和良性疾病对照组中分别为 46 .9pg/mL和 18.6pg/mL(P <0 .0 5 )。以对照组 X± 2S为界值 ( 2 1.3pg/mL) ,则肿瘤组血清p5 3抗体阳性率为 2 1.4%,而对照组则为 5 .6 %(P <0 .0 5 )。肿瘤伴远处转移者p5 3抗体阳性率高于无转移者 (P <0 .0 0 5 ) ,手术后p5 3抗体浓度显著下降 (P <0 .0 5 )。血清p5 3抗体与CEA显著相关 (P <0 .0 0 5 )。血清p5 3抗体对消化系肿瘤诊断的敏感性、特异性、准确性分别为 2 1.4%、94.4%、5 0 %。结论　血清p5 3抗体浓度在消化系肿瘤中异常升高 ,是特异性的肿瘤标志物。     

Serum p53 antibody as a predictor of early recurrence in patients with postoperative esophageal squamous cell carcinoma

It is reported that surveillance of serum p53 antibody (Ab) is a useful marker in detecting esophageal squamous cell carcinoma (ESCC). But there is little reported about prognostic significance of serum p53-Ab in postoperative patients with ESCC. The aim of this study is to evaluate the significance of preoperative serum p53-Ab as a marker of early recurrence after curative resection for ESCC. Enzyme-linked immunosorvent assay (ELISA) was used to analyze serum p53-Ab before treatment in 44 patients with ESCC. Carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC-Ag) were examined by immunoradiometric assay. The patients who were strongly positive and positive in serum p53-Ab were more likely to have early recurrence after curative resection than seronegative patients. There were no significant correlations between CEA, SCC-Ag positivity and early recurrence. We found that serum p53-Ab was useful to predict a risk of early recurrence after curative surgical resection for ESCC.     

Circulating p53 Antibody in Patients with Colorectal Cancer

The presence of serum anti-p53 antibody has been reported to be associated with survival of patients with breast cancer, ovarian cancer, and hepatocellular carcinoma. To clarify prognostic significance of p53 antibody in colorectal cancer, serum p53 antibody was measured in patients with colorectal cancer. The 89 patients included 71 with colorectal cancer and 18 with colon polyp. An enzyme-linked immunosorbent assay was used to detect p53 antibodies in serum. Clinicopathological parameters such as age, sex, degree of differentiation of cancer, location of tumor, liver metastasis, stage classification, Dukes classification, CEA, CA19-9, and immunostaining of p53 and anti-p53 antibody were evaluated as prognostic factors of colorectal cancer. p53 antibody was positive in 18 of 71 (25%) with colorectal cancer, whereas it was positive in only 1 of 18 (6%) with colon polyp. The patients with p53 antibody had higher CEA and CA19-9 levels, higher positive rates of p53 protein expression in cancer cells, and higher liver metastasis rates. The p53 antibody positivity at stage classification I–IIIb/Dukes classification A–C was significantly lower than that at stage classification IV/Dukes classification D. Overall survival in colorectal cancer patients with p53 antibody was significantly shorter than in those without p53 antibody. A Cox regression analysis showed that liver metastasis, stage classification, Dukes classification, CA19-9, and p53 antibody were significant prognostic factors in colorectal cancer. Serum anti-p53 antibody could serve as one of the prognostic factors in patients with colorectal cancer.     

锤头状核酶对肝癌突变基因p53的抑制作用

目的 探讨p53核酶对肝癌细胞突变型抑癌基因p53的抑制作用。方法 应用计算机设计并合成针对突变型p53(249位密码子AGG→AGT)的锤头状核酶RZ，构建其体外转录和真核表达载体，检测核酶对突变型p53(mtp53)的体外切割作用，并在Lipofect AMINE^TM2000的介导下转染肝癌细胞MHCC97，应用逆转录聚合酶联反应(RT—PCR)检测核酶对肝癌细胞突变型p53的抑制作用。结果 测序证实核酶基因被正确克隆人体外转录载体pBSKU6和真核载体pEGFPC1中。体外切割效率为42％，而野生型p53(wtp53)没有被切割。在Lipofect AMINETM2000的介导下成功转染肝癌细胞MHCC97，RT—PCR检测证实突变型p53的mRNA水平明显下降，细胞内的切割效率为69％。结论 p53核酶可成功抑制肝癌细胞中突变型p53的表达，为肝癌的基因治疗提供了一个新的选择。     

Differential expression of retinoic acid receptors and p53 protein in normal, premalignant, and malignant esophageal tissues

Purpose: Esophageal cancer remains a significant health problem worldwide. The very low 5-year survival rates and rapid increase in the incidence of adenocarcinoma indicate the urgent need for early identification of and new approaches to the prevention and treatment of this cancer. Methods: To find biomarkers for early identification of the disease, we analyzed nuclear retinoic retinoid receptor mRNAs, p53 protein, and the proliferation marker Ki 67 in surgical specimens of normal, mildly, and severely dysplastic and malignant esophageal tissues. Results: Nuclear retinoid receptors (RAR-α, RAR-γ, and RXR-α) were expressed in most (79%–100%) normal, dysplastic, and malignant esophageal mucosae, whereas expression of RAR-β was progressively lost from normal esophagus to carcinoma (84%–54%). In contrast, expression of p53 protein and Ki 67 were dramatically increased in severely dysplastic and cancerous tissues of the esophagus (from 5% to 62%). Conclusions: Loss of RAR-β expression and accumulation of p53 and Ki 67 proteins may serve as biomarkers for esophageal cancer. Received: 17 April 2000 / Accepted: 12 July 2000     

河南安阳地区p53基因第72密码子多态性与HPV相关食管癌的研究

目的探讨河南安阳地区p53基因第72密码子多态性与人乳头瘤病毒(HPV)相关食管癌的关系.方法收集安阳肿瘤医院食管癌病例110例,用PCR方法检测HPV,PCR-RFLP方法分析p53基因第72密码子多态性,病例对比研究方法分析在食管癌病例中HPV感染与p53基因第72密码子多态性的关系.结果 PCR检测结果表明,河南安阳地区食管癌组织中HPV检出率为59.1%;HPV阳性者中,Arg/Arg基因型的频率是60.0%,HPV阴性者中仅为17.8%,两者有统计学显著性(P＜0.05).结论 p53基因第72密码子多态性可能是安阳地区HPV相关食管癌的易感因素之一,携带p53Arg/Arg基因型的个体更容易发生HPV相关的食管癌.     

Expression of p53, p16 and cyclooxygenase-2 in esophageal cancer with tissue microarray

OBJECTIVE: The aim of this study was to obtain a comprehensive survey on the expression of p53, p16 and cyclooxygenase‐2 (COX‐2) in esophageal cancer progression and their clinical significance. METHODS: A tissue microarray containing 86 specimens from esophageal cancer and 40 specimens from adjacent non‐cancer tissue was constructed to survey the expression of p53, p16 and COX‐2 by immunohistochemistry. The influence of each biomarker on the histotype of esophageal lesion was assessed by logistic regression analysis. RESULTS: The expression of p53 and COX‐2 was significantly higher in tumorous tissue than in non‐tumorous tissue. As to p16, no significant difference was detected between tumorous and non‐tumorous tissue. A significant correlation was observed among p53, COX‐2 and p16 expression. Logistic regression analysis revealed that the risk factors of a tumorous histotype were the positive expression of p53 (odds ratio [OR] = 18.214) or COX‐2 (OR = 42.703), and no reciprocal relationship to neoplastic progression was recognized with p53, p16 and COX‐2. CONCLUSIONS: p53 and COX‐2 were independent predictors in esophageal carcinogenesis. Esophageal tissue with a positive expression of p53 or COX‐2 was more likely to develop esophageal cancer.     

野生型p53基因转移对血管内膜损伤后再狭窄的防治作用

为防止血管成形术后管腔再狭窄，我们构建了介导野生型ｐ５３基因转移的复制缺陷型重组腺病毒（Ａｄ－ｐ５３），将Ａｄ－ｐ５３感染日本大耳兔球囊损伤后的髂动脉，并通过携带ＬａｃＺ基因重组腺病毒感染观察基因转染效率。结果可见Ａｄ－ｌａｃＺ感染损伤后的动脉３天后血管内膜、中膜、外膜均有ＬａｃＺ基因的阳性表达；Ａｄ－ｐ５３感染损伤后的髂动脉２周后可见血管内膜增厚程度、内膜与中膜的比例明显减小，管腔狭窄程度明显减轻，ｐ５３蛋白大量表达，与对照组相比具有显著差异。证明野生型ｐ５３基因转移能明显抑制血管损伤后的内膜增殖，为野生型ｐ５３基因转移防治血管内膜损伤后再狭窄奠定了实验基础。     

肝细胞癌基因P53异常的研究

目的：分析我国重庆地区肝细胞癌Ｐ５３基因失活机制及突变谱。方法：采用ＰＣＲ—ＲＦＬＰＰＣＲＳＳＣＰ和ＰＣＲ直接测序技术对来自我国重庆地区２８例肝细胞癌Ｐ５３抑癌基因结构异常进行了分析。结果：６１．５１％的肝癌存在ｐ５３的杂合缺失：５０％肝癌伴有ｐ５３基因突变，其突变模式为突普通散在于５６７和８外显子，其中第７外显子２４９们密友情子突弯率最高（２１％）；具有突变的肝癌多同时伴夺缺失。伴有ｐ５３基因结构异常的肝癌均属进展期。结论：我国重庆地区肝癌存在Ｐ５３基因结构异常，Ｐ５３基因结构异常，ｐ５３基因突变模式反映了该地区肝癌发生可能与肝炎病互和黄贡互素两种因素及其相互作用有关；ｐ５３基因结构异常属肝癌晚期事件，可能参加与肝癌的进展过程。     

应用阳离子脂质体介导内皮抑素和(或)p53基因治疗Lewis肺癌小鼠的实验研究

目的 观察SA阳离子脂质体介导内皮抑素基因和（或）p53基因对Lewis肺癌小鼠移植瘤生长、转移的抑制作用。方法 取Lewis肺癌细胞悬液建立C57BL/6j小黑鼠肺癌动物模型后,选择40只随机分成5组,每组8只,分别为空白对照组、实验对照组、p53治疗组、pEnd治疗组、pEnd＋p53联合治疗组。小鼠成瘤后,瘤内注射SA阳离子脂质体介导的内皮抑素基因和（或）p53基因,每周2次,共6周。观察瘤体大小变化、小鼠营养状况、生存期等。结果 各治疗组均能抑制肿瘤生长及肺内转移,与对照组比较有统计学意义（P〈0.01）,小鼠活动能力、饮食、对外界刺激反应能力等均优于对照组。结论 应用SA阳离子脂质体介导内皮抑素基因和（或）p53基因瘤内注射可有效地抑制Lewis肺癌移植瘤的生长、转移,小鼠生存期明显延长于对照组。内皮抑素基因与p53基因联合未发现协同作用。     

介导野生型p53基因转移的重组腺病毒的构建研究

应用同源重组方法成功地构建了携带野生型ｐ５３基因的复制缺陷型重组腺病毒，通过光镜、电镜、酶切、ＰＣＲ共扩增等方法证实了构建载体的正确性，并使常规的同源重组方法进一步改进，简化了载体构建的操作程序，结果准确，成功率高。本结果可用于以腺病毒为载体进行肿瘤、心血管疾病等基因治疗的研究。