幽门螺杆菌感染与胃癌组织p16基因变异的关系

目的：探讨幽门螺杆菌（Hp)感染与胃癌组织p16基因变异的关系。方法43例胃癌患者的新鲜癌手术标本、相应的癌旁正常组织及血清标本为本组研究对象,分别采用PCR及银染PCR－SSC癌组织p16基因的纯合性缺失及突变情况;幽门螺杆菌感染状况通过PCR及血清学试验确定。结果（1）43例胃癌中,Hp阳性30例,阳性率为69．77％,其中CagA阳性24例,阳性率为80％。（2）30例Hp阳性胃癌中,有12例发生p16基因变异,发生率为40％;13例Hp阴性胃癌中,4例p16基因发生变异,发生率为30．77％,Hp阳性组与阴性组相比较p16基因变异率差异无显著性（P＞0．05）。（3）30例Hp阳性胃癌中,CagA阳性与阴性组p16基因变异率分别为41．67％（10．24）及33．33％（2／6）,两组变异率比较差异无显著（P＞0．05）。结论Hp及CagA阳性Hp感染与胃癌组织p16基因变异无显著相关性,Hp感染可能不是其改变或必须因素。     

Expression of p16 gene and Rb protein in gastric carcinoma and their clinicopathological significance

AIM: To analyze the correlation between the protein expression of p16 and Rb genes in gastric carcinoma (GC), to investigate the role of p16 gene in invasion and lymph node metastasis of GC, and to examine the deletion and mutation in exon 2 of p16 gene in GC. METHODS: The protein expression of p16 and Rb genes was examined by streptavidin-peroxidase conjugated method (S-P) in normal gastric mucosa, dysplastic gastric mucosa and GC. The deletion and mutation of p16 gene were examined by polymerase chain reaction (PCR) and polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) respectively in normal gastric mucosa and GC. RESULTS: The positive rates of P16 and Rb protein expression respectively were 96% (77/80) and 99% (79/80) in normal gastric mucosa, 92% (45/50) and 80% (40/50) in dysplastic gastric mucosa, 48% (58/122) and 60% (73/122) in GC. The positive rates of P16 and Rb protein expression in GC were significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P<0.05). The positive rate of P16 protein expression in mucoid carcinoma (10%, 1/10) was significantly lower than that in poorly differentiated carcinoma (51%, 21/41), undifferentiated carcinoma (58%, 15/26) and signet ring cell carcinoma (62%, 10/16) (P<0.05). The positive rates of P16 protein in 30 cases of paired primary and lymph node metastatic GC were 47% (14/30) and 17% (5/30) respectively, being significantly lower in the later than in the former (P<0.05). There was no mutation in exon 2 of p16 gene in the 25 freshly resected primary GCs. But five cases in the 25 freshly resected primary GCs displayed deletion in exon 2 of p16 gene. The positive rate of both P16 and Rb proteins was 16% (14/90), and the negative rate of both P16 and Rb proteins was 8% (7/90) in 90 GCs. The rate of positive P16 protein with negative Rb protein was 33% (30/90). The rate of negative P16 protein with positive Rb protein was 43% (39/90). There was reverse correlation between P16 and Rb expression in 90 GCs CONCLUSION: The loss protein expression of p16 and Rb genes is related to GC. The loss expression of P16 protein is related to the histopathologic subtypes and lymph node metastasis of GC. Expression of P16 and Rb proteins in GC is reversely correlated. The deletion but not mutation in exon 2 of p16 gene may be involved in GC.     

错配修复基因hMSH2启动子甲基化与胃癌的关系

目的:探讨hMSH2基因启动子区5CpG岛高甲基化在胃癌发生过程中的作用.方法:应用甲基化特异性PCR(methylationspecific PCR,MSP)方法检测胃癌及非癌组织中hMSH2基因启动子区甲基化状态.结果:40例胃癌中hMSH2基因启动子区高甲基化24例(60%),其癌旁黏膜组织中有15例(37.5%)发生甲基化,14例慢性萎缩性胃炎组织中有5例(35.7%)发生甲基化,6例慢性浅表性胃炎组织中未见甲基化.四组甲基化水平相比,差别有统计意义(P＜0.05).胃癌组甲基化水平高于癌旁组,差别有统计意义(P＜0.05).癌旁组、慢性萎缩性胃炎组、慢性浅表性胃炎组三组甲基化水平相比,差别无统计意义.胃癌各临床病理参数组之间相比差别无统计意义.结论:胃癌组织中hMSH2基因启动子区高甲基化可能是导致其错配修复功能缺陷的重要原因之一;而错配修复功能缺陷在胃癌的发生中起着重要作用,但可能与其发展关系不大.     

错配修复基因hMLH1甲基化与胃癌的关系

目的:通过研究散发性胃癌中错配修复基因hMLH1 mRNA的表达及其启动子区5'CpG岛甲基化状态,探讨hMLH1基因异常甲基化在胃癌发生过程中的作用.方法:应用甲基化特异性PCR(methylation specific PCR,MSP)检测60例胃癌组织及其癌旁黏膜组织中hMLH1基因启动子区的甲基化状态,逆转录PCR(RT-PCR)检测两种组织中hMLH1 mRNA表达情况.结果:胃癌组织hMLH1 mRNA表达水平明显低于癌旁组织(t=4.082,P<0.01),hMLH1基因启动子区高甲基化18例(30%),其癌旁黏膜组织中未发现有甲基化.hMLH1基因启动子区甲基化与胃癌的临床病理参数之间无明显的相关性.hMLH1 mRNA表达阴性的21例病例中,17例(81%)发生甲基化,而hMLH1 mRNA表达阳性的39例中仅有1例(2.5%)发生甲基化,hMLH1 mRNA表达降低与甲基化之间存在明显的相关性(χ2=8.0182,P=0.0046).结论:胃癌组织中hMLH1基因启动子区甲基化与其mRNA表达缺失密切相关,是导致hMLH1基因错配修复功能缺陷的重要原因之一.     

原发胃癌中p16基因及其甲基化状态、表达异常的研究

目的：检测胃癌组织中p16基因及启动了甲基化状态和p16蛋白表达情况。方法：选择p16基因及启动子区域,用PCR－SSCP、MSP（甲基化特异的PCR）法、测序和免疫组化等方法对100例胃癌患者的癌组织和癌旁组织进行检测。结果：71％的病例p16表达阴性,54％的病例具有p16基因启动子区的高甲基化,50％的病例同时有p16表达阴性和p16基因启动子区的高甲基化,无突变和纯合缺失检出。结论：提示p16基因启动子区域高甲基化是胃癌中p16基因失活的主要原因。     

Two distinct pathways of p16 gene inactivation in gallbladder cancer

AIM： TO examine the mechanism of inactivation of the p16 gene in gallbladder cancer, and to investigate p16 alterations and their correlation with clinicopathological features.
METHODS： Specimens were collected surgically from 51 patients with gallbladder cancer. We evaluated the status of protein expression, loss of heterozygosity（LOH）, homozygous deletion and promoter hypermethylation using immunohistochemistry, microsatellite analysis, quantitative real-time polymerase chain reaction （PCR） and methylation-specific PCR, respectively. In addition, mutations were examined by direct DNA sequencing.
RESULTS： Homozygous deletions of the p16 gene exon2, LOH at 9p21-22, p16 promoter hypermethylation, and loss of p16 protein expression were detected in 26.0% （13/50）, 56.9% （29/51）, 72.5% （37/51） and 62.7% （32/51）, respectively. No mutations were found. LOH at 9p21 correlated with the loss of p16 protein expression （P 〈 0.05）. Homozygous deletion of the p16 gene, a combination LOH and promoter hypermethylation, and multiple LOH at 9p21 were significantly correlated with the loss of p16 protein expression （P 〈 0.05）. LOH at 9p21 and promoter hypermethylation of the p16 gene were detected in 15.4% （2/13） and 92.3% （12/13） of the tumors with homozygous deletion of the p16 gene, respectively. P16 alterations were not associated with clinicopathological features.
CONCLUSION： Our results suggest that LOH and homozygous deletion may be two distinct pathways in the inactivation of the p16 gene. Homozygous deletion, a combination of LOH and promoter hypermethylation, and multiple LOH are major mechanisms of p16 inactivation in gallbladder cancer.     

肿瘤抑制基因p53及p16与胃癌生物学行为的关系

目的探讨肿瘤抑制基因ｐ５３和ｐ１６异常与胃癌生物学行为的关系．方法采用免疫组化ＡＢＣ法检测５８例原发性胃癌（男３８例，女２０例，年龄３７岁～７６岁），Ｐ５３和Ｐ１６蛋白的表达变化．所有组织均新鲜取材，并迅速用８５０ｍｌ／Ｌ酒精固定，石蜡包埋，连续切片．结果受检组织中ｐ５３和ｐ１６阳性表达率分别为５１７％（３０／５８）和４８３％（２８／５８）．Ｐ５３蛋白在低分化胃癌（７００％）、进展期胃癌（５６９％）、淋巴结阳性胃癌（７４１％）中的表达率高于相应的高分化、早期、淋巴结阴性胃癌的表达率（２７３％，１４３％，３２３％）（Ｐ＜００５），且ｐ５３高表达多见于弥散型胃癌（同肠型胃癌比）、累及浆膜的胃癌也较局限于粘膜层的胃癌有更高的Ｐ５３蛋白表达（Ｐ＜００５）；Ｐ１６蛋白表达与胃癌大多数生物学行为无明显关系，但其在淋巴结阳性胃癌中的表达率（３３３％），低于淋巴结阴性胃癌中的表达率（６１３％）；相关性分析显示；ｐ５３阳性组织大多伴有Ｐ１６蛋白阳性表达（Ｐ＜００５）．结论Ｐ５３蛋白异常表达对胃癌生物学行为有广泛影响，Ｐ１６蛋白表达缺失可能是胃癌淋巴结转移的重要促发因素．     

Methylation and mutation analysis of p16 gene in gastric cancer

AIM: To study methylation, frequencies of homozygous deletion and mutation of p16 gene in gastric carcinoma.METHODS: The methylation pattern in exon i and exon 2 of p16 gene was studied with polymerase chain reaction (PCR), using methylation sensitive restriction endonuclease HpaⅡ and methylation insensitive restriction endonuclease MspI. PCR technique was used to detect homozygousdeletions of exon 1 and exon 2 of p16 gene and single strand conformation polymorphism (SSCP) technique was used to detect the mutation of the gene.RESULTS: Hypermethylation changes in exon 1 and exon 2 of p16 gene were observed in 25 % and 45 % of 20 gastric cancer tissues, respectively, while no methylation abnormality was found in normal tissues. The homozygous deletion frequency of exon i and exon 2 of p16 gene in 20 gastric cancer tissues was 20 % and 10 %, respectively. No mutation was found in exon i of p16 gene, while abnormal single strands were found in 2 (10 %) cases in exon 2 as detected by SSCP.CONCLUSION: The results suggest that hypermethylation and abnormality of p16 gene may play a key role in the progress of gastric cancer. Hypermethylation of exon 2 of p16 gene may have effects on the carcinogenesis of gastric mucosa and may be a later event.     

急性白血病患者端粒酶催化亚单位和p16基因表达与端粒酶活性的关系

目的 :探讨端粒酶催化亚单位 (hTERT)和p 16基因表达与端粒酶活性的关系及其在急性白血病发生过程中的作用。方法 :采用TRAP和RT PCR法分别检测 5 2例急性白血病患者 (白血病组 )及 2 0例非白血病且骨髓象正常者 (对照组 )的端粒酶活性与hTERTmRNA表达。用免疫细胞化学SP法测定上述对象的P 16蛋白表达。结果 :白血病组端粒酶活性与hTERTmRNA的阳性率分别为 75 .0 %和 80 .8%,而对照组均为阴性。白血病组hTERTmRNA表达与端粒酶活性呈显著正相关 (r =0 .6 5 ,P <0 .0 1)。白血病组及对照组P 16蛋白阳性表达率分别为 34 .6 %和 95 .0 %,二者比较差异有非常显著性意义 (P <0 .0 1)。白血病组P 16蛋白表达与端粒酶活性呈显著负相关 (r =- 0 .81,P <0 .0 1)。结论 :hTERTmRNA表达和p 16基因失活可能在急性白血病发生发展过程中有一定作用 ,急性白血病细胞端粒酶激活可能与hTERTmRNA表达及p 16基因失活有关。     

p15ink4B and p16ink4 gene inactivation in acute lymphocytic leukemia

Malignant cells from 52 children with acute lymphocytic leukemia (ALL) were investigated for inactivation of the p15ink4B and p16ink4 genes and other genetic alterations on chromosome 9p21. Homozygous deletions of the p15ink4B and/or the p16ink4 genes were detected in 16 cases and a further 9 cases showed evidence of allelic loss either by hemizygous deletion or loss of heterozygosity (LOH) for 9p21 markers. Most cases had loss of both genes, but 5 patients had lost only p16ink4 and 2 cases had homozygous loss of p15ink4B only. Sequence analysis of all exons of p15ink4B and p16ink4 was performed in patients with hemizygous deletions or LOH for 9p21 markers. A frame shift mutation of p16ink4 exon 1 was shown in 1 case, whereas all other clones carried the wild- type sequence of p15ink4B and p16ink4 in the remaining allele. The data suggest that both the p15ink4B and p16ink4 genes can be inactivated in ALL. The existence of a hitherto undefined tumor-suppressor gene on chromosome 9p cannot be ruled out.     

Alteration of tumor suppressor gene p16 and Rb in gastric cancinogesis

Ａｌｔｅｒａｔｉｏｎｏｆｔｕｍｏｒｓｕｐｐｒｅｓｓｏｒｇｅｎｅｐ１６ａｎｄＲｂｉｎｇａｓｔｒｉｃｃａｎｃｉｎｏｇｅｓｉｓＺＨＯＵＱｉ１，ＺＯＵＪｉａｎＸｉａｎｇ２，ＣＨＥＮＹｕＬｏｎｇ２，ＹＵＨｕｉＺｈｅｎ３，ＷＡＮＧＬｉＤｏｎｇ１，ＬＩＹｏ...     

肿瘤抑制基因p16和Rb在胃上皮癌变过程中的表达

目的观察肿瘤抑制基因ｐ１６，Ｒｂ蛋白在胃上皮癌变过程中的表达．方法内镜直视下对胃粘膜癌组织和非癌组织进行取材，常规组织学处理石蜡包埋，连续切片．用免疫组化ＡＢＣ法检测浅表性胃炎１２例，萎缩性胃炎１５例，不典型增生２０例和４０例癌组织中ｐ１６，Ｒｂ蛋白的表达状况．     

Expression, deleton and mutation of p16 gene in human gastric cancer

AIM To investigate the relationship between the expression of p16 gene and the gastric carcinogenesis,depth of invasion and lymph node metastases, and to evaluate the deletion and mutation of exon 2 in p16 gene in gastric carcinoma. METHODS The expression of P16 protein was examined by streptavidin-peroxidase conjugated method (S-P); the deletion and mutation of p16 gene were respectively examined by polymerase chain reaction (PCR) and polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) in gastric carcinoma. RESULTS Expression of P16 protein was detected in 96.25% (77/80) of the normal gastric mucosa, in 92.00% (45/50) of the dysplastic gastric mucosa and in 47.54% (58/122) of the gastric carcinoma. The positive rate of P16 protein expression in gastric carcinoma was significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P＜0.05). The positive rate of P16 protein expression in mucoid carcinoma 10.00% (1/ 10) was significantly lower than that in poorly differentiated carcinoma 51.22% ( 21/ 41 ),undifferentiated carcinoma 57.69% (15/26) and signet ring cell carcinoma 62.50% (10/ 16) (P＜0.05). The positive rate of p16 protein in 30 cases paired primary and lymph node metastatic gastric carcinoma: There was 46.67% (14/30) in primary gastric carcinoma, 16.67% (5/30) in lymph node metastatic gastric carcinoma. The positive rate of lymph node metastatic carcinoma was significantly lower than that of primary carcinoma (P＜0.05). There was of p16 gene mutation in exon 2, but 5 cases displayed deletion of p16 gene in exon 2 in the 25 primary gastric carcinomas. CONCLUSIONS The expression loss of P16 protein related to the gastric carcinogenesis, gastric carcinoma histopathological subtypes and lymph metastasis. The mutation of p16 gene in exon 2 may not be involved in gastric carcinogenesis. But the deletion of p16 gene in exon 2 may be involved in gastric carcinogenesis.     

鼻咽癌组织中p73基因甲基化水平与放疗疗效的关系

目的探讨鼻咽癌组织中p73基因甲基化水平与鼻咽癌放射敏感性的关系。方法采用Pyrosequencing法检测51例鼻咽癌组织中p73基因甲基化水平。放疗后随访其总生存率及无瘤生存率,用Kaplan-Meier法分析p73基因甲基化与鼻咽癌患者放疗后无瘤生存率和总生存率的关系。结果51例中p73基因无甲基化者21例,3a总生存率为83．98％,3a无瘤生存率为73．89％;有甲基化者30例,3a总生存率及无瘤生存率分别为73．49％和60．65％。p73甲基化者比无甲基化者总生存率低（P〈0．05）,无瘤生存率也低于无甲基化者,但P〉0．05。结论鼻咽癌组织中p73基因甲基化与鼻咽癌放疗疗效有关。     

胃癌病变术前超声内镜检查分期与p53基因突变的关系

为探讨胃癌超声内镜检查(EUS)分期与其p53基因突变的相关性,应用EUS对73例胃癌患者进行术前分期,同时采用银染PCR-SSCP方法检测内镜活检组织标本p53基因突变。p53基因总突率为54.8％;T3(64.3％)T和T4期(67.9)％突变率明显高于T1(0％)或T2期(25.0％)病例(p<0.05);有淋巴结转移的病例突变率为67.6％,亦明显高于无转移时的41.7％(p<0.05)。提示p53基因突变在胃癌的发生发展及转移中起重要作用。随着癌细胞浸润转移进展,其p53基因突变率增高,术前EUS分期与这种改变有较好的相关性.在临床上分析胃癌的预后可能有参考意义。