Expression, deletion [was 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.     

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.     

Relationship between inactivation of p16 gene and gastric carcinoma

AIM: To investigate the relationship between inactivation of p16 gene and gastric carcinoma, and the mechanism of inactivation of p16 gene in gastric carcinogenesis. METHODS: 40 fresh tumor tissue specimens were taken from primary gastric cancer patients. Expression of P16 protein was detected by immunohistochemical method. Deletion and point mutation of p16 gene were analyzed by polymerase chain reaction (PCR) and DNA sequencing, respectively. RESULTS: The frequency of loss of P16 protein expression in the gastric cancer tissue, adjacent nontumor tissue, and distal normal tissue was 77.5 % (31/40), 55.0 % (22/40), and 17.5 % (7/40), respectively (P<0.005). Homozygous deletion of exon 1 and exon 3 was observed in two and three cases, respectively, giving an overall frequency of homozygous deletion of 12.5 %. All five cases had diffuse type gastric carcinoma. No p16 gene point mutation was detected. CONCLUSION: These findings suggest a close correlation between inactivation of p16 gene and gastric carcinoma. Further investigations are needed to testify the mechanism of inactivation of p16 gene in gastric carcinogenesis.     

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.     

胃癌及癌前病变组织中CD44v6表达的意义

目的探讨CD44v6基因表达与胃癌发生及胃癌生物学行为的关系.方法应用抗CD44v6蛋白的单克隆抗体,采用免疫组化ABC方法对正常胃粘膜(n=10)、各级胃粘膜异型增生(轻度n=16,中度n=12,重度n=14)、早期胃癌(n=16)及进展期胃癌(n=52)进行研究,并与胃癌类型、大小、有无淋巴结转移等作了比较分析.结果正常胃粘膜CD44v6为阴性,随着胃粘膜病变的进展,CD44v6蛋白的表达率逐渐升高,至进展期胃癌,表达率达到顶峰.轻、中、重度异型增生表达率分别为12%,33%,43%;早期胃癌及进展期胃癌的表达率分别为44%和73%.各级异型增生表达率之间的差异无显著性,而进展期胃癌表达率显著高于早期胃癌(P＜0.05),淋巴结转移组的表达率显著高于淋巴结未转移组(82%vs56%,P＜0.05),肠型胃癌的表达率高于弥漫型胃癌(78%vs56%,P＜0.05),CD44v6蛋白的表达与胃癌肿块大小无相关性.结论胃粘膜重度异型增生在CD44v6基因表达上已具有明显的潜在恶性趋势,CD44v6基因表达阳性的胃癌具有更强的浸润及淋巴结转移的能力.     

胃癌p53基因表达与转移及预后的研究

目的观察胃癌组织ｐ５３基因的超表达及其与预后的关系。方法用抗人Ｐ５３基因蛋白单克隆抗体Ｓ＿Ｐ免疫组织化学方法，观察１２８例胃癌组织ｐ５３表达状况，并对ｐ５３表达与胃癌淋巴结转移状态和术后５年生存率进行比较分析。结果胃癌组织１２８例的ｐ５３表达阳性率为４３８％（５６／１２８）；ｐ５３表达阳性和阴性组的胃癌局部和远处淋巴结转移率分别为６７９％（３８／５６）和５１４％（３７／７２），两者经统计学处理无显著性差异（Ｐ＞００５）。获得随访９８例，胃癌术后５年生存率的随访结果显示，ｐ５３阳性和阴性组分别为３８１％（１６／４２）和３０１％（１７／５６），两组间无统计学意义（Ｐ＞００５）。结论胃癌的发生与ｐ５３基因突变关系密切，并可用免疫组化检测，但Ｐ５３基因蛋白在胃癌组织中的超表达，似不能作为判断胃癌预后的参考指标，应进一步探讨     

Relation of overexpression of S phase kinase-associated protein 2 with reduced expression of p27 and PTEN in human gastric carcinoma

AIM: To investigate the significance of S phase kinase associated protein 2 (Skp2) expression in human gastric carcinoma and the relation between expressions of Skp2, p27 and PTEN. METHODS: Immunohistochemical analysis was performed on 138 gastric carcinoma specimens, their paired adjacent mucosa specimens, 102 paired lymphatic metastatic carcinoma tissue specimens, 30 dysplasia specimens, 30 intestinal metaplasia specimens, 10 chronic superficial gastritis specimens and 5 normal gastric mucosa specimens for Skp2 expression and on 138 gastric carcinoma specimens for p27 and PTEN expression. RESULTS: Skp2 labeling frequency was significantly higher in intestinal metaplasia (12.68±0.86) and adjacent mucosa (19.32±1.22) than in normal gastric mucosa (0.53±0.13) and chronic superficial gastritis (0.47±0.19) (P = 0.000); in dysplasia (16.74±0.82) than in intestinal metaplasia (P = 0.000); in gastric primary carcinoma (31.34±2.17) than in dysplasia and adjacent mucosa (P = 0.000); in metastasis gastric carcinoma in lymph nodes (39.76±2.00) than in primary gastric carcinoma (P = 0.037), respectively. Skp2 labeling frequency was positively associated with differentiation degree (rho = 0.315, P = 0.000), vessel invasion (rho = 0.303, P = 0.000) and lymph node metastasis (rho = 0.254, P = 0.000) of gastric cancer. Expression of Skp2 was negatively associated with p27 (rho = -0.451, P = 0.000) and PTEN (rho = -0.480, P = 0.000) expression in gastric carcinoma. p27 expression was positively associated with PTEN expression in gastric carcinoma (rho = 0.642, P = 0.000). CONCLUSION: Skp2 overexpression may be involved in carcinogenesis and progression of human gastric carcinoma in vivo, possibly via p27 proteolysis. PTEN may regulate the expression of p27 by negatively regulating Skp2 expression.     

RhoC基因的过量表达在胃癌中的意义

目的探讨RhoC基因在胃癌中的表达及其与临床病理因素之间的关系。方法采用免疫组化S-P法检测97例胃癌组织及89例癌旁组织中RhoC的表达。结果在89例癌旁组织中82例不表达RhoC,97例胃癌组织中,75例(77.31%)表达RhoC。两者之间有显著差异(P=0.00)。RhoC蛋白的过量表达与患者性别及肿瘤分级、分化和淋巴结转移未见相关性,与肿瘤浸润深度,肿瘤分期存在相关性(P<0.05)。结论RhoC蛋白在胃癌中过量表达与胃癌的发生发展密切相关,可以作为胃癌的预后判断指标之一。     

叉头框蛋白Q1在结直肠癌和结直肠腺瘤中的异常表达和基因突变

目的 探讨叉头框蛋白Q1(FOXQ1)与结直肠肿瘤的临床病理相关性.方法 连续收集云南省第一人民医院2007年6月至2009年6月174份研究样本,包括内镜电切的结直肠腺瘤(CRA)50例、手术切除的结直肠癌(CRC)76例和正常结直肠黏膜组织(距癌旁≥8 cm)48例.用免疫组化SP法检测上述组织中的FOXQ1表达.以PCR扩增和直接测序法检测其中23例CRC、22例CRA和18例正常结直肠黏膜样本中的FOXQ1基因突变.结果 FOXQ1在正常结直肠黏膜中无表达,在CRC和CRA中的表达阳性率均显著高于正常结直肠黏膜组织(76.3%比0.0%,26.0%比0.0%,P＜0.01);在CRC中的表达阳性率显著高于CRA(76.3%比26.0%,P＜0.01).FOXQ1除在CRC的肿瘤细胞胞核中有阳性表达外,在胞质和细胞外基质中亦有阳性表达.FOXQ1在CRC基质的表达阳性率在Dukes C或D期显著高于Dukes A和Dukes B(61.5%比3.3%,61.5%比5.0%,P＜0.01);有淋巴结转移者显著高于无淋巴结转移者(61.5%比4.0%,P＜0.01).23例CRC中发现1例FOXQ1基因突变;22例CRA和18例正常结直肠黏膜组织中未检测出突变.结论 FOXQ1的异常高表达可能在CRC的发生发展中起重要作用,且可能参与了CRC的侵袭和淋巴结转移.FOXQ1基因突变可能不是FOXQ1在CRC异常表达的主要原因.

Abstract：

Objective To investigate the clinical pathological association of FOXQ1 with colorectal carcinoma (CRC) and colorectal adenoma (CRA). Colorectal mucosa specimens were collected between Jane 2007 and June 2009 in the First hospital of Yunnan prorince, and consisted of CRC (n=76), CRA (n=50) and normal (n=48,≥8 cm apart from cancer) tissues. Methods The expression of FOXQ1 in colorectal mucosa with was detected using immunohistochemistry (SP method). PCR amplification and direct DNA sequencing were used to identify FOXQ1 gene mutations in 23 CRC, 22 CRA and 18 normal specimens. Results There was no expression of FOXQ1 in normal specimens. Aberrant expression of FOXQ1 in either CRC or CRA specimens was significantly higher than in normal colorectal mucosa tissue (76.3% vs 0.0%, 26.0% vs 0.0% respectively, P＜0.01).Aberrant expression rates of FOXQ1 was significantly higher in CRC than that in CRA (76.3% vs 26.0%, P＜0.01). Expression level of FOXQ1 was increase gradually along with the pathological process of colorectal adenoma-carcinoma sequence. In CRC, the aberrant expression of FOXQ1 was not only distributed in nuclear of the tumor cells, but also found in the cytoplasm and the extracellular matrix. For CRC patients, the aberrant expression rates of FOXQ1 in extracellular matrix in Dukes C/D was significantly higher than that in Dukes A/B (61.5% vs 3.3%, 61.5% vs 5.0% respectively,P＜0.01);The aberrant expression of FOXQ1 in extracellular matrix in patient with lymph node metastasis was significantly higher than those without lymph node metastasis (61.5 % vs 4.0 %, P＜0.01). FOXQ1 gene mutation was only identified in one out of 23 CRC specimens, but not found in 22CRA nor 18 normal colorectal mucosa samples. Conclusions Aberrant expression of FOXQ1 may play an important role in the carcinogenesis of CRC and FOXQ1 gene may be involved in the cancer erosion and lymph node metastasis. FOXQ1 mutation is not the primary cause of aberrant FOXQ1 expression in CRC.     

抑癌基因P16在肺鳞癌和肺腺癌中的表达及临床意义

目的 探讨p16基因产物在肺鳞癌和肺腺癌中的表达及其意义。方法 本组56例原发性非小细胞肺癌，其中鳞癌37例，腺癌19例。用免疫组织化学PCR法检测患者肺癌新鲜标本p16蛋白表达水平。结果 56例肺癌标本中p16蛋白阳性表达率为58.9%（33／56），伴有淋巴结转移者其阳性表达率41.4%（12／29）显著低于无淋巴结转移者（P16阳性表达率为77.8%（21／27），P＜0.01）。P16蛋白阴性表达者的1年、3年生存率分别为59.7%、44.1%，显著低于p16蛋白阳性表达者85.2%、71.8%。结论 p16蛋白表达与肺鳞癌和肺腺癌的组织类型，淋巴结转移及预后有关。p16蛋白状态可作为判断肺癌预后的指标之一。     

EMMPRIN、MT1-MMP蛋白在原发胃癌和胃癌转移淋巴结中的表达及意义

目的:探讨细胞外基质金属蛋白酶诱导因子-EMMPRIN(extracellular matrix metalloproteinase inducer,EMMPRIN)、膜型基质金属蛋白酶-1(membrane-type matrix metalloproteinase-1,MT1-MMP)蛋白在原发胃癌和胃癌转移淋巴结中的表达差异及与人胃癌临床病理特征的关系,以及二者之间是否有协同作用.方法:应用量子点免疫荧光组织化学技术检测人胃癌组织芯片(包括204例胃癌组织,21例非癌性胃黏膜组织)和20例胃癌转移淋巴结组织中EMMPRIN和MT1-MMP的蛋白表达并评分.结果:在正常胃黏膜组织、慢性萎缩性胃炎伴肠上皮化生、胃癌和胃癌转移淋巴结组织中,EMMPRIN和MT1-MMP蛋白表达呈逐渐递增的趋势,正常胃黏膜组分别与胃癌组、胃癌转移淋巴结组相比,2种蛋白表达的差异均有显著性.EMMPRIN蛋白表达与浸润深度、高TNM分期和淋巴结转移之间均呈显著正相关,而与其他临床病理参数均无关.MT1-MMP蛋白表达仅与高TNM分期和伴有淋巴结转移呈显著正相关.EMMPRIN和MT1-MMP蛋白表达之间呈显著正相关(r=0.584,P=0.001).结论:EMMPRIN与MT1-MMP蛋白在胃癌的发生与进展中有协同作用;在胃癌转移淋巴结中的表达高于原发胃癌,但差异无显著性.     

燃煤型砷中毒患者p16基因缺失及启动区CpG岛甲基化的观察

目的检测燃煤型砷中毒(地砷病)患者p16基因缺失及启动区甲基化的变异,探讨p16基因异常改变在地砷病发生发展乃至癌变过程中的作用。方法采用多重PCR法对103例砷中毒患者和110例正常对照人群p16基因第1、第2外显子缺失情况进行检测;同时采用甲基化特异性PCR法(MSP)和PCR产物测序技术对95例砷中毒患者和100例正常对照人群p16基因启动区甲基化情况进行分析。结果(1)正常对照组p16基因缺失率为5．45％;病例组为14．56％,以第2外显子缺失为主,其中轻、中、重度中毒组p16基因缺失率分别为9．09％、12．50％和19．51％;非癌变组和癌变组p16基因缺失率分别为8．70％和38．89％。以上差异有统计学意义(P<0．05或P<0．01)。(2)对照组p16基因甲基化阳性率为2．00％;病例组为42．11％,其中轻、中、重度中毒组p16基因甲基化阳性率分别为26．32％、41．67％和50．00％;非癌变组和癌变组阳性率分别为21．74％和55．56％。以上差异均有统计学意义(P<0．05或P<0．01)。结论p16基因缺失及启动区甲基化在地砷病的发生发展乃至癌变过程中起重要作用。     

胃癌形成过程中p16IN4a、Runx3和O-6-甲基鸟嘌呤-DNA甲基转移酶基因甲基化及其表达研究

目的 研究胃癌形成过程中p16INK4a、Runx3和O-6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因启动子区的高甲基化状态,同时检测MGMT的蛋白表达情况.探讨抑癌基因启动子区高甲基化与胃癌发生的关系.方法 选择经透明帽法进行首次黏膜病变切除者43例,其中异型增生27例,早期胃癌16例.选择胃镜活检证实为慢性萎缩性胃炎伴肠上皮化生者14例.另取20例正常胃黏膜活检组织作为对照.采用甲基化特异聚合酶链反应(MSP)检测每例组织中p16INK4a、Runx3和MGMT基因启动子区的甲基化状态,对所有甲基化p16INK4a产物进行测序,免疫组化检测MGMT蛋白表达情况.结果 肠上皮化生、异型增生和早期胃癌中p16INK4a基因甲基化率依次为14.3%(2/14)、22.2%(6/27)和37.5%(6/16);Runx3基因甲基化率依次为14.3%(2/14)、48.1%(13/27)和50.0%(8/16);MGMT基因甲基化率依次为7.1%(1/14)、48.1%(13/27)和50.0%(8/16).20名正常对照均未检出基因甲基化,与异型增生和早期胃癌相比差异有统计学意义(P＜0.05).Runx3和MGMT两种基因在异型增生和早期胃癌中的甲基化率显著高于肠上皮化生组(P＜0.05).各组病变中三种基因甲基化联合分析发现,异型增生和早期胃癌中甲基化的基因种类高于肠上皮化生组.差异有统计学意义(P＜0.01).基因甲基化与息者年龄、性别、幽门螺杆菌感染以及病变部位无相关性,但p16INK4a和MGMT基因甲基化与血清癌胚抗原水平升高显著相关(P值分别为0.003和0.039).MGMT基因启动子区高甲基化与其蛋白失表达密切相关(χ2=12.821,P=0.001).结论 抑癌基因启动子区高甲基化是基因失活的主要机制,可能是胃癌发生的早期分子事件.p16INK4a、Runx3和MGMT基因启动子区高甲基化在胃癌形成过程中起着重要的作用.     

老年胃癌及癌前病变中p16及cyclinD1蛋白的表达

目的　探讨老年胃癌及癌前病变中p16、cyclinD1蛋白的表达、相互关系及其意义。　 方法 　应用免疫组化链霉卵白素 (SP)法检测老年胃癌、不典型增生、萎缩性胃炎、浅表性胃炎及正常胃组织中p16、cyclinD1蛋白的表达。　结果　p16蛋白在正常胃粘膜表达率最高 (85 7% ) ,并随病变进展 (浅表性胃炎 -萎缩性胃炎 -不典型增生 -腺癌 ) ,表达率呈下降趋势 (分别为 84 4% ,76 9% ,2 9 0 % ,3 4 3 % ) ,其中不典型增生 ,腺癌组与正常组比较有显著差异 (P <0 0 5 ) ,cy clinD1蛋白随病变发展 (萎缩性胃炎、不典型增生、腺癌 )表达率升高 (分别为 19 2 % ,3 8 7% ,5 5 7% ) ,其中腺癌与萎缩性胃炎比较差异显著 (P <0 0 5 )。相关性分析显示大多数受检老年胃癌组织中 ,p16与cyclinD1呈反向表达。　 结论　p16和cyclinD1在胃上皮癌变过程中起着重要作用 ,其在胃癌中的反向表达趋势提示两者可能存在相互抑制机制。p16蛋白低表达和cyclinD1蛋白高表达可能是胃癌发生过程中的早期分子事件。     

Bcl-2、Bax、P21-WAF1、P16-MTS1蛋白在胃腺癌演化系列中的表达

目的　通过对胃腺癌演化系列胃粘膜中Bcl 2、Bax、P2 1 WAF1、P16 MTS1蛋白的检测 ,探讨胃腺癌发生的机制及四种蛋白表达与胃腺癌生物学行为的关系。方法　 1、利用免疫组化S P法检测胃癌演化系列胃粘膜中Bcl 2、Bax、P2 1 WAF1、P16 MTS1蛋白的表达 ;2、利用SPSS统计软件包作统计学分析处理。结果　在CSG、CAG、IM系列胃粘膜中Bax、Bcl 2表达先高后低 ,而P16 MTS1、P2 1 WAF1表达先低后高 ,(P <0 .0 5 )。高分化胃腺癌中Bcl 2、Bax、P2 1 WAF1、P16 MTS1表达较低分化者高 ;P16 MTS1表达在非贲门癌中比贲门癌中高 ,P2 1 WAF1表达在有淋巴结转移的胃腺癌中较低 (P<0 .0 5 )。结论　Bax、Bcl 2的高表达及P2 1 WAF1、P16 MTS1的表达受抑可能参与胃腺癌发生 ;四种蛋白异常表达均与胃腺癌分化呈正相关 ;P16 MTS1、P2 1 WAF1的表达异常与胃腺癌的发生部位及淋巴结转移相关。     

DNA甲基化对大肠癌相关基因表达的调控意义

目的:探讨大肠癌发生与演进中p16,Rb,cyclin D1甲基化状态与蛋白表达的关系及意义．方法:提取正常黏膜、腺瘤、癌旁组织及癌组织基因组DNA,应用MSP法检测不同病变阶段组织中各基因的甲基化状态,并对其与蛋白表达及临床病理参数的关系进行分析．结果:在大肠癌发生与演进过程中,p16,Rb 基因甲基化率呈增高趋势,cyclin D1基因甲基化率呈下降趋势,p16(切缘:r=-0．185,P =0．173;腺瘤:r=-0．381,P=0．013:癌旁:r= -0．419,P=0．001;癌:r=-0．516,P=0．000)、 cyclin D1(切缘:r=-0．282,P=0．035;腺瘤:r= -0．329,P=0．033;癌旁:r=-0．298,P=0．026; 癌:r=-0．618,P=0．000)基因甲基化程度分别与其蛋白表达呈明显负相关,且在癌组织分化程度(p16:X2=11.232,P=0．002,cyclin D1:X2 =9．144,P=0．015)、浸润深度(p16:X2=6．229, P=0．013;cyclin D1:X2=8．023,P=0．006)和淋巴结转移(p16:X2=5．707,P=0．016;cyclin D1: X2=7．794,P=0．005)上有显著性差异．Rb基因的甲基化状态在Rb表达抑制上不起主要作用．结论:大肠癌p16高甲基化和cyclin D1低甲基化可能是p16失活和cyclin D1过表达的主要机制,在大肠癌的发生、发展中发挥重要作用, 对于大肠癌的早期诊断、恶性程度及预后判断有重要意义．     

胃癌组织中KISS-1和MMP-9的表达及其意义

目的探讨肿瘤转移抑制基因K ISS-1及基质金属蛋白酶9（MMP-9）与胃癌侵袭、转移的关系,为研究胃癌的转移机制及治疗提供理论基础。方法采用逆转录聚合酶链反应（RT-PCR）检测36例胃癌组织及36例正常胃组织中K ISS-1 mRNA及MMP-9 mRNA的表达情况,分析其与胃癌患者各临床病理指标的关系及二者的相关性。结果 K ISS-1 mRNA在胃癌组织中的阳性表达率及表达水平均低于正常胃组织（P均〈0.01）,并且其低表达与淋巴结转移密切相关（P〈0.05）;MMP-9 mRNA在胃癌组织中的阳性表达率及表达水平均高于正常胃组织（P均〈0.05）,MMP-9 mRNA的高表达与癌的浸润深度和淋巴结转移密切相关（P均〈0.05）;K ISS-1与MMP-9表达呈负相关（P〈0.05）。结论 K ISS-1表达缺失和MMP-9过表达可能与胃癌的侵袭相关。     

Expression of the c-erbB-2 proto-oncogene product in gastric carcinoma and precancerous lesions

AIM: To study the relationship between the expression of the c-erbB-2 proto-oncogene product with gastric mucosal carcinogenesis and the behavior of gastric carcinoma.METHODS: Specimens from nine normal gastric mucosa, 23 gastric mucosal dysplasia (10 slight, six moderate, seven severe), 18 early gastric carcinoma, and 30 advanced gastric carcinoma were marked with P₁₈₅ monoclonal antibody using the immunohistochemical peroxidase-avidin-biotin complex method. The relation between P₁₈₅ expression with histological type, size, and lymph node metastasis of gastric carcinoma were analyzed.RESULTS: Normal gastric mucosa was negative for P₁₈₅; Only a few cells in the neck region of the mucosal glands were very weakly positive. Relatively high positive rates were found in the slight, moderate, and severe dysplasia specimens (50%, 83.3%, and 85.7%, respectively). A 22.2% and 56.7% P₁₈₅-positive rate was found in early gastric carcinoma and in advanced gastric carcinoma, respectively. Statistically, the P₁₈₅-positive rates in severe dysplasia and advanced gastric carcinoma were significantly higher than that in early gastric carcinoma (P < 0.05). The P₁₈₅-positive rate in the group with lymph node metastasis was significantly higher than that of the group without lymph node metastasis (59.3% vs 23.8%, P < 0.05), but P₁₈₅ expression was not related to histological type and size of gastric carcinoma.CONCLUSION: The c-erbB-2 proto-oncogene might participate in gastric mucosal proliferation, repair, and carcinogenesis, and gastric carcinoma with P₁₈₅ expression might have a stronger potential of infiltration and metastasis.