原发性胃癌p16INK4a基因缺失和突变的研究

目的探讨p16INK4a基因缺失和突变在胃癌发病机制中所起的作用。方法采用多重PCR、PCR-SSCP和DNA测序对62例胃癌、癌旁组织及10例正常胃黏膜标本中p16INK4a基因纯合性缺失和突变进行检测。结果62例胃癌中发现p16INK4a基因第一外显子和第三外显子各有2例纯合性缺失,缺失率6.5%(4/62),PCR-SS-CP和DNA测序发现1例p16INK4a基因第一内含子区碱基插入,突变率1.6%(1/62),癌旁和正常胃黏膜均未发现缺失和突变。结论在原发性胃癌中,p16INK4a基因纯合性缺失率很低、突变罕见。     

葡萄胎中CDKN2A基因纯合性缺失和突变的研究

目的：探讨细胞周期依赖性激酶抑制基因（CDKN2A基因，包括p16^INK4a和p14^ARF基因）外显子1、2的纯合性缺失和突变情况与葡萄胎发生的关系。方法：对38例葡萄胎和30例早孕绒毛的新鲜组织标本进行基因组DNA抽提、PCR扩增．而后应用变性高效液相色谱分析（DHPLC）的方法对扩增产物进行突变检测。结果：1）38例葡萄胎组织样本中．5例发生p16^INK4a基因外显子1的纯合性缺失．其纯合性缺失率为13．16％；而30例早孕绒毛组织标本中．未发现p16^INK4a基因外显子1的纯合性缺失。p16^INK4a外显子1的纯合性缺失率在早孕绒毛组织和葡萄胎组织中差异具有统计学意义（P=0．036）；2）38例葡萄胎组织样本和30例早孕绒毛组织样本中，无一例发生p14^ARF基因外显子1和p16^INK4a外显子2的纯合性缺失：3）经DHPLC检测，38例葡萄胎组织样本和30例早孕绒毛组织样本中，p16^INK4a基因外显子1、2和p14^ARF基因外显子1扩增产物的所有谱图均为单一峰型，未检测到任何位点的突变发生。结论：p16^INK4a基因外显子1的纯合性缺失与葡萄胎的发生具有一定的相关性；在葡萄胎中，CDKN2A基因的遗传变异主要是由于此基因的纯合性缺失造成的，突变可能不是此基因变异的主要形式。     

抑癌基因FHIT第8和第5外显子在原发性肝癌中纯合性缺失与点突变的研究

目的　对 2 0例原发性肝细胞肝癌 (HCC)的抑癌基因 FHIT外显子 5、外显子 8的纯合性缺失和点突变进行检测。方法　收集 HCC手术标本 ,提取癌细胞 DNA,采用 PCR方法研究 FHIT外显子 5、外显子 8的纯合性缺失 ;使用 PCR- SSCP方法研究 FHIT外显子 5和外显子 8的点突变。结果　发现在 2 0例 HCC中外显子 5的纯合性缺失率为 10 .0 (2 / 2 0 ) ,外显子 8的纯合性缺失率为 30 .0 % (6 / 2 0 ) ;有 1例外显子 5和外显子 8均缺失 ;FHIT的异常率为 35 .0 % (7/ 2 0 )。在被检的肿瘤组织细胞中 ,未发现 FHIT外显子 5和外显子 8存在点突变。在被检的正常细胞中未发现 FHIT缺失和点突变的情况。结论　 FHIT的缺失只发生在 HCC的肿瘤细胞中。在 HCC中 ,外显子 (尤其是外显子 8)的纯合性缺失是 FHIT基因失活的重要方式之一。点突变可能不是 HCC中 FHIT失活的主要方式     

p16及p15基因在子宫颈癌中的纯合性缺失及其临床意义

目的 :探讨抑癌基因p16、p15基因的纯合性缺失在子宫颈癌的发生发展中的作用。方法 :应用比较PCR技术检测 34例子宫颈癌组织和 2 0例正常宫颈组织中p16、p15基因的纯合性缺失。结果 :p16、p15基因的纯合性缺失率分别为 11 8%、14 7% ,p16、p15基因的纯合性缺失与组织学类型、临床分期及组织学分级无关。结论 :p16、p15基因的纯合性缺失在子宫颈癌的发生发展中可能起到一定的作用     

不对称PCR-SSCP检测鼻咽癌p130基因研究

目的:探讨p130基因改变与鼻咽癌发生、发展的关系。方法:提取鼻咽癌组织DNA,用不对称单链构象多态性(SSCP)PCR技术,分别对20例散发性鼻咽癌患者及3个鼻咽癌高发家系进行性p130基因第11、17和19外显子纯合性缺失及突变研究,以20例慢性鼻咽炎患者的鼻咽部组织做为对照。结果:散发性鼻咽癌患者有相同的p130 E11、E17纯合性缺失2例,未发现p130E19缺失;对照组中检出1例p130E11、E17纯合性缺失,也无p130E19缺失;鼻咽癌家系未发现缺失和突变。结论:鼻咽癌中p130 E11、E17纯合性缺失可能涉及到p130/Rb2基因的改变,在鼻咽癌的发生发展中起一定的作用,而且p130/Rb2基因作为一种抑癌基因可能成为鼻咽癌新的基因治疗手段的候选基因。     

p16及p15基因在子宫颈癌中的纯合性缺失及其临床意义

目的：探讨抑癌基因ｐ１６、ｐ１５基因的纯合性缺失在子宫颈癌的发生发展中的作用。方法：应用比较ＰＣＲ技术检测３４例子宫颈癌组织和２０例正常宫颈组织中ｐ１６、ｐ１５基因的纯合性缺失。结果：ｐ１６、ｐ１５基因的纯合性缺失率分别为１１．８％、１４．７％，ｐ１６、ｐ１５基因的纯合性缺失与组织学类型、临床分期及组织学分级无关。结论：ｐ１６、ｐ１５基因的纯合性缺失在子宫颈癌的发生发展中可能起到一定的作用。     

子宫颈癌的p16、p15基因缺失研究

目的　探讨p16、p15基因的纯合性缺失与子宫颈癌发生及发展的相关性。方法　本文采用PCR技术对 5 7例治疗前子宫颈癌组织的 p16、p15基因的纯合性缺失进行检测。结果　p16的纯合性缺失率为 15 7% ( 9 5 7) ,Ⅰ Ⅲ期宫颈癌的不同病理类型均有 p16基因的缺失 ,但没有显著性差异。p15基因未发现缺失。 结论　p16基因的纯合性缺失与子宫颈癌的发生有关 ,未发现缺失p15基因     

脑胶质瘤 p16基因的纯合性缺失、高甲基化、突变及表达

目的：研究p16基因在脑胶质瘤中的纯合性缺失、高甲基化和突变等结构变化及其与表达之间的关系。方法：应用聚合酶链反应（polymerase chain reaction,PCR)和PCR甲基化银染分析技术（PCR-methylation assay with silver staining,PCR-MASS)对50例脑胶质瘤标本进行了p16基因纯合性缺失和甲基化检测；用PCR－SSCP和DNA测序技术进行了p16基因突变分析，用免疫组化检测了p16蛋白的表达。结果：50例脑胶质瘤中23例p16蛋白表达阳性，27例表达阴性，表达缺失率54％；9例（18％）纯合性缺失、7例（14％）高甲基化、2例（4％）突变。结论：p16基因在脑胶质瘤中有多种形式的结构异常，其结构的变化使p16蛋白表达障碍。p16基因纯合性缺失和高甲基化是基因失活的重要机制，在脑胶质瘤的发生、发展中起重要作用。     

胃癌中p16基因缺失与突变的研究

目的：探讨p16基因外显子2的缺失和突变与胃癌发生发展的关系.方法：应用新鲜组织标本基因组DNA抽提、PCR-SSCP分析的方法,对30例胃癌及癌旁组织中p16基因外显子2的缺失和突变进行检测.结果：胃癌组织样本中p16基因外显子2的缺失率为10.00%,突变率为10.00%,两者之和为20.00%,癌旁组织样本中未发现缺失和突变,统计学分析有显著性差异（P〈0.01）.结论：p16基因外显子2的缺失和突变与胃癌的发生具有一定的相关性.     

胃癌Kai-1基因缺失与突变的研究

目的:探讨Kai-1基因的缺失与突变在胃癌演进与转移中的意义.方法:提取30例胃癌患者的肿瘤组织(16例无淋巴转移,14例有淋巴转移),30例癌旁正常组织的RNA,RT-PCR扩增,电泳检测,测序验证Kai-1基因的缺失情况;并提取发生缺失的肿瘤组织的DNA,PCR扩增,测序探讨Kai-1基因的突变情况.结果:30例组织标本中12例出现Kai-1基因exon9缺失(10例杂合缺失,2例纯合缺失),30例癌旁正常组织中有5例出现Kai-1基因exon9缺失(5例杂合缺失);在胃癌组织中Kai-1基因缺失频率显著高于在癌旁正常组织(P<0.05);在有淋巴转移的胃癌组织中,缺失的频率明显高于无淋巴转移的胃癌组织(P<0.05),在胃癌中晚期(Ⅲ-Ⅳ期)明显高于早期(Ⅰ-Ⅱ期)(P<0.05),而Kai-1基因的缺失频率与胃癌患者的年龄、性别、组织学类型以及分化程度无关 (P>0.05).结论:Kai-1基因缺失与突变可能与胃癌演进、转移有关,检测其缺失或突变可作为判断胃癌的演进与转移的客观临床指标.     

Mutational Analysis of CDKN2 (CDK4I/MTS1) Gene in Tissues and Cell Lines of Human Prostate Cancer

To study mutation of the CDKN2 gene in prostate cancer, samples from 51 Japanese patients and four human prostate cancer cell lines were examined by single-strand conformation polymorphism analysis and direct sequencing. Only one out of 51 (2%) patients revealed a mutation, which was a 24 bp deletion from the 5'-untranslated region to codon 3, resulting in loss of the initiation site. One of the four cell lines revealed a missense mutation, a GAC→TAC (Asp→Tyr) at codon 84. These results indicate that mutation of the CDKN2 gene is rare in prostate cancer and thus does not contribute significantly to the pathogenesis of human prostate cancer. Prostate cancer cell lines may acquire more frequent abnormality of the CDKN2 gene than tumor tissues.     

CDKN2A novel mutation in a patient from a melanoma-prone family

CDKN2A is thought to be the main candidate gene for melanoma susceptibility. Deletion or mutations in the CDKN2A gene may produce an imbalance between functional p16 and cyclin D, causing abnormal cell growth. We here describe a novel mutation consisting of a 1 bp deletion at nucleotide position 201 (codon 67) (CACGGcGCG) resulting in a truncated protein (stop codon 145). The patient, a female subject from a melanoma-prone family, presented at the age of 47 years with a superficial spreading melanoma of the trunk. Her father had colon cancer at the age of 43 years and melanoma at 63 years, her uncle suffered from gastric cancer, and her grandfather had laryngeal cancer.     

CDKN2A gene inactivation in epithelial sporadic ovarian cancer.

The tumour suppressor gene CDKN2A, located on chromosome 9p21, encodes the cell cycle regulatory protein p16. Inactivation of the CDKN2A gene could lead to uncontrolled cell growth. In order to determine the role of CDKN2A in the development of sporadic ovarian cancer, loss of heterozygosity at 9p21-22, homozygous deletion, mutation and methylation status of the CDKN2A gene as well as CDKN2A expression were examined in a panel of serous papillary ovarian cancer. The frequency of loss of heterozygosity (LOH) for one or more informative markers at 9p21-22 was 65% (15/23). The most common deleted region was located between interferon (IFN)-alpha and D9S171. Homozygous deletions and mutations of the CDKN2A gene were not found. There was no evidence of methylation in exon 1, but methylation in exon 2 of CDKN2A gene was found in 26% (6/23). Absence of CDKN2A gene expression was shown in 27% (6/22) at mRNA level and 21% (4/19) at protein level. These data suggest that the CDKN2A gene is involved in the tumorigenesis of ovarian cancer, but the mechanisms of CDKN2A gene inactivation in serous papillary ovarian cancer remains unclear.     

Inactivation of p16/CDKN2 and p15/MTS2 is associated with prognosis and response to chemotherapy in ovarian cancer

To define the involvement of p16/CDKN2 and p15/MTS2 tumor-suppressor genes for response to chemotherapy in primary epithelial ovarian cancer, we analyzed alterations of the gene in 45 patients who were treated with primary cytoreductive surgery followed by 6 courses of cis-diamminedichloroplatinum (II) (cisplatin)-based combination chemotherapy. Homozygous deletion of p16/CDKN2 and p15/MTS2 genes was found in 8 (18%) and 15 (33%) cases, respectively. Response to the chemotherapy was confirmed by finding at second surgery after the chemotherapy in 26 patients, resulting in 17 responders and 9 nonresponders. The abundance of gene deletion in nonresponders (56%) was significantly higher (p = 0.0463) when compared to that in responders (18%). Moreover, the deletion of genes was a significant poor prognostic factor (p = 0.0441) in advanced ovarian cancer. These results suggest that deletion of p16/CDKN2 and/or p15/MTS2 is a potential indicator for poor chemotherapy response and adverse prognosis in ovarian cancer patients.     

CDKN2A基因突变与晚期非小细胞肺癌患者临床病理特征及预后的相关性分析

目的:评估细胞周期依赖性激酶抑制基因（CDKN2A）突变与晚期非小细胞肺癌（NSCLC）患者的临床病理特征和预后的关系。方法:采用第二代测序技术筛选肿瘤标本中的CDKN2A基因突变。卡方检验分析CDKN2A基因突变与晚期NSCLC临床病理特征之间的相关性。Logistic回归分析CDKN2A基因突变与临床一线治疗评效之间的相关性。Kaplan-Meier曲线和COX模型评估患者生存。结果:NSCLC患者CDKN2A基因突变率为3.81％（8/210）。CDKN2A基因突变在鳞状细胞癌患者中更常见（P=0.005）。多数CDKN2A基因突变型患者一线治疗评效是疾病进展（PD）,而野生型患者多为疾病控制（DCR）（P=0.012）。CDKN2A基因突变型患者的中位生存时间（OS）明显短于野生型患者（19.1 vs 42.8个月,P=0.010）,并且突变型患者的无进展生存时间（PFS）也明显缩短（3.5 vs 9.7个月,P=0.001）。多因素分析显示CDKN2A基因突变、T4期、淋巴结转移和ECOG高评分是影响晚期NSCLC患者生存的独立危险因素。结论:CDKN2A基因突变对晚期NSCLC患者的临床病理特征和预后有重要影响。CDKN2A基因突变患者的生存期明显缩短。     

胃癌中 p16基因表达、缺失及突变的检测

目的研究p16基因表达与胃癌发生发展、侵袭、转移的关系及p16基因外显子2缺失、突变在胃癌发生中的地位。方法运用链霉菌抗生物素蛋白-过氧化酶(S-P)免疫组织化学方法检测胃癌及癌前病变组织中p16蛋白的表达;采用聚合酶链反应(PCR)、聚合酶链反应-单链构象多态性(PCR-SSCP)分析方法检测胃癌中p16基因外显子2的缺失、突变。结果(1)p16蛋白表达阳性率①正常胃粘膜96.25％(77／80),不典型增生92.00％(45／50),胃癌47.54％(58／122),胃癌组中p16蛋白表达低于正常胃粘膜及不典型增生（P<0.05）;②粘液腺癌(10.00％,1／10)低于低分化腺癌(51.22％,21／41)、未分化癌(57.69％,15／26)和印戒细胞癌(62.50％,10／16)（P<0.05）;③30例原发癌和淋巴结转移癌配对标本中p16蛋白表达阳性率原发癌46.67％（14/30）,淋巴结转移癌16.67％(5／30),淋巴结转移癌低于原发癌(P<0.05);(2)p16基因缺失与突变分析25例胃癌中检测出缺失5例,但未发现突变。结论①p16蛋白表达缺失与胃癌的发生、组织学类型及淋巴结转移有关。②p16基因外显子2缺失可能与胃癌发生有关;而p16基因突变可能与胃癌发生无关。     

胃癌组织中P53基因缺失、重排和点突变的研究

本文用Southern杂交方法分析了30例胃癌组织中P53基因的缺失和重排,发现9例(30％)有缺失或重排;用PCR-RFLP方法分析了胃癌组织中P53基因第248、249位密码子的点突变,42例中2例(4.8％)有248位密码子的点突变。     

Clinical course of bladder neoplasms and single nucleotide polymorphisms in the CDKN2A gene

Point mutations and single nucleotide polymorphisms (SNPs) in the CDKN2A gene in bladder cancer patients have been resolved only to a limited extent. The exact frequency of mutations remains uncertain and reports on SNPs are lacking. In this population-based study we investigated mutations and polymorphisms in the CDKN2A gene in bladder cancer patients from all hospitals within the Stockholm County. Mutations were determined in 4 exons of the CDKN2A gene in tumor-tissues from 172 bladder cancer patients and 2 single nucleotide polymorphisms in the 3' UTR of the CDKN2A gene were studied in 309 cases. Missense mutations were identified in only 4 of 172 (2.3%) cases, including 1 in the germ-line. Frequencies of the 500 C-->G and 540 C-->T polymorphisms in the 3' UTR of the CDKN2A in bladder cancer cases were not statistically significantly different compared to an ethnically matched control population. The tumor-specific survival was significantly shorter in patients with either the 500 C-->G or 540 C-->T polymorphism than those with wild-type CDKN2A gene (P = 0.02). Our results corroborate the earlier findings that single base mutation is not the prime mode of inactivation of the CDKN2A gene in bladder cancer. Further, the results indicate, a role for the 3' UTR polymorphisms in the CDKN2A gene in tumor invasiveness.