30例结直肠癌p53基因突变的初步研究

为了解结直肠癌ｐ５３基因突变的情况，应用聚合酶链反应－单链构象多态（ＰＣＲ－ＳＳＣＰ）银染技术对３０例人结直肠癌中ｐ５３基因第５、６、７、８外显子进行检测，发现１６例（５３．３３％）存在ｐ５３基因突变，其中第７外显于７例，第５外显子４例，第６外显子３例，第８外显子２例。结果表明：（１）结直肠癌中普遍存在ｐ５３基因突变；（２）ｐ５３基因突变与结直肠癌的发生和发展有关；（３）ＰＣＲ－ＳＳＣＰ银染技术是一种敏感、可靠且简便、快速和经济的方法，尤其适用于临床实验室进行大规模的样本筛选。     

免疫组化和PCR—SSCP检测p53基因异常的一致性探讨

目的：探讨免疫组化检测ｐ５３蛋白表达和ＰＣＲ－ＳＳＣＰ检测ｐ５３基因突变的一致性。方法：单克隆抗体ＤＯ－７检测８５例非小细胞肺癌（ＮＳＣＬＣ）的ｐ５３蛋白表达，ＰＣＲ－ＳＳＣＰ检测其中３１例腺癌的ｐ５３基因突变。结果：８５例ＮＳＣＬＣ中ｐ５３蛋白表达阳性率为６８％（５８／８５），３１例腺癌中ｐ５３蛋白表达阳性率为６１％（１９／３１），１４例（４６％）出现ｐ５３基因５～８外显子突变，ｐ５３蛋白免疫组化和ＰＣＲ－ＳＳＣＰ检测ｐ５３基因突变无显著相关（χ２＝０．１，Ｐ＝０．７６），其一致率为５２％。结论：ｐ５３蛋白表达并不能很好地反映ｐ５３基因突变。     

DMBA-TPA-MNNG诱发小鼠皮肤肿瘤中p53基因突变

目的探讨ｐ５３基因与化学致癌剂诱发小鼠皮肤肿瘤的关系。方法运用ＰＣＲＳＳＣＰ和直接ＤＮＡ测序法，检测３７例ＤＭＢＡＴＰＡＭＮＮＧ诱发的小鼠皮肤肿瘤［包括６例乳头状瘤，１５例高分化鳞状细胞癌（ＳＣＣＩ）和１６例中分化鳞状细胞癌（ＳＣＣⅡ）］中，ｐ５３基因第５～８外显子的序列改变。结果乳头状瘤均未见ｐ５３基因突变，而２５８％（８／３１例）ＳＣＣ测得突变，其中ＳＣＣⅠ和ＳＣＣⅡ突变率分别为２６６％（４／１５例）和２５％（４／１６例）。在这８例肿瘤中共有９个突变，其中７个位于第８外显子，有７个为Ｇ→Ａ转换。结论ｐ５３基因突变发生于该三步化学致癌法诱发的小鼠皮肤乳头状瘤向ＳＣＣ恶性转化过程中。     

p53基因突变与食管癌生物学行为的关系

目的为了探讨ｐ５３基因突变与食管癌生物学行为及预后的关系。方法应用ＰＣＲ－ＳＳＣＰ结合ＤＮＡ直接银染测序，对３０例散发性食管癌组织ｐ５３基因第５～８外显子进行检测。结果检出１１例阳性，突变检出率为３６．７％。９例为点突变，其中错义突变４例、无义突变２例、同义突变３例，其余２例为碱基插入和缺失导致的移码突变。统计学分析显示：中低分化食管癌的ｐ５３突变率为５６．３％，高分化组为１４．３％，两组相比有非常显著性差异（Ｐ＝０．０２５）；癌组织浸润累及食管壁全层的ｐ５３突变率５２．６％显著高于未累及全层组９．１％（Ｐ＝０．０２４）；有淋巴结转移组与无淋巴结转移组相比，ｐ５３突变率分别为６１．５％和１７．６％也具有非常显著性差异（Ｐ＝０．０２４）。结论ｐ５３基因突变与食管癌多种生物学行为如组织分化程度、肿瘤浸润程度及淋巴结转移有明显相关性。因此检测食管癌组织中是否存在ｐ５３基因突变有助于判断食管癌的恶性程度和患者的预后。还讨论了ｐ５３基因的“显性负效应”及同义突变的遗传学效应。     

胃腺癌p53基因第5,7外显子突变的研究

采用聚合酶链式反应－单链构型多态（ＰＣＲ－ＳＳＣＰ）技术结合ＰＣＲ产物直接方法初步分析了２３例原发性胃癌ｐ５３基因第５、７外显子的突变，经ＳＳＣＰ检测发现第５外显子无一例异常泳动变位，而第７外显子发现２例阳性结果，经测序证实一例发生了剪切位点突变，另一例突变为静息突变。     

用非同位素PCR－SSCP方法检测石蜡包埋乳腺癌p53基因点突变

应用一非同位素ＰＣＲ－ＳＳＣＰ方法检测常规石蜡包埋乳腺癌组织中ｐ５３基因点突变。结果显示６０例乳腺癌中，１４例有异常电泳带，表明这些病例相应ＤＮＡ片段中发生了点突变，其中４例位于第５～６外显子，３例位于第７外显子，７例位于第８外显子。免疫组化法检测突变型ｐ５３蛋白的表达，１３例为阳性，其中１１例ＳＳＣＰ检测到异常电泳带，另２例突变可能发生在所检测的基因片段以外。而５例ＳＳＣＰ分析发现基因突变者，免疫染色却为阴性，主要可能由于石蜡包埋组织中ｐ５３抗原性减弱或消失所致，因此，ＳＳＣＰ法检测ｐ５３基因点突变更为准确、可靠，而且可初步将突变定位在基因某一片段。本研究结果表明非同位素ＰＣＲ－ＳＳＣＰ是一简便、快速、有效的检测基因点突变的方法，特别适用于对大量标本基因点突变的筛选；ｐ５３基因点突变与突变型ｐ５３蛋白免疫染色阳性呈相关关系，但并不完全吻合。     

CD44基因拼接体,p53基因突变和染色体倍性与大肠癌转移之间 …

目的：探讨大肠癌ＣＤ４４ｖ６表达，ｐ５３基因突变和染色体倍性和大肠癌转移之间的关系和作用机理。方法：流式细胞仪测定大肠癌细胞倍性及其在细胞周期各相中的分布；ＲＴ－ＰＣＲ方法及特异探针Ｄ３对大肠癌细胞进行Ｓｏｕｔｈｅｒｎ Ｂｌｏｔ，并对杂交条带进行辉度扫描；银染ＰＣＲ单链构象多态笥（ＳＳＣＰ０技术检测大肠癌细胞ｐ５３基因突变。结果：正常对照，良性腺瘤，肿瘤未转移和肿瘤转移组其ＣＤ４４ｖ６阳笥率和ｐ５     

肺癌p53蛋白表达和基因突变与临床病理的相关研究

目的 检测肺癌中ｐ５３蛋白表达和基因突变状况及其与临床病理和预后的相关性。方法：应用免疫组织化学（ＬＳＡＢ法）和聚合酶链反应－单链构象多态性分析（ＰＣＲ－ＳＳＣＰ）二种方法。结果 检测肺鳞癌４６例，共９５例。免疫组化ｐ５３蛋白总阳性率为５０．５％（４８／９５例），肺鳞癌阳性率为５６．５％（２６／４６例）、肺腺癌为４４．７％（２２／４９例）。ＰＣＲ－ＳＳＣＰ检测ｐ５３基因突变率为４１．１％（３９／９     

人肺癌组织中p53,Rb基因突变研究

为探讨肺癌发生的分子遗传学机理，采用聚合酶链反应及聚合酶链反应－单链构象多态性技术，对４１例人肺癌组织中ｐ５３基因外显子５～８及Ｒｂ基因外显子１４～１６、２２～２３进行了突变分析。结果显示：ｐ５３基因突变１６例（１６／４１，３９％），分布于外显子５～７；Ｒｂ基因异常４例（４／４１，９．８％），其中外显子１４～１６区域部分缺失和外显子２２～２３区域突变各２例；在９例小细胞肺癌标本中，７例发生ｐ５３及Ｒ５基因的突变，其中１例存在ｐ５３基因两个外显子突变，另１例同时存在ｐ５３及Ｒｂ基因的突变。对部分ｐ５３基因突变标本序列分析，均在１个或３个密码子上存在导致ｐ５３蛋白异常的单碱基置换或插入突变。以上结果表明：肺癌、特别是小细胞肺癌的发生可能与ｐ５３及Ｒｂ基因的突变有关。     

子宫颈癌组织中HPV16癌基因及p53基因的检测

利用ＨＰＶ１６Ｅ６、Ｅ７基因特异性引物，ＰＣＲ技术及抗癌基因ｐ５３外显子７特异性引物，ＰＣＲ－ＳＳＣＰ技术对３５例进展期子宫颈癌组织进行研究，发现：（１）３５例标本中ＨＰＶ１６Ｅ６、Ｅ７ＤＮＡ的总检出率为７１．４２％（２５例），其中同时检出Ｅ６、Ｅ７为３１．４２％（１１例），另外８．５７％及３１．４２％（３例及１１例）仅分别检出Ｅ６、Ｅ７序列。（２）全组未见１例有ｐ５３基因外显子７的点突变及等位基因缺失。该结果说明ＨＰＶ１６与本地区妇女子宫颈癌发生有密切关系，并且癌组织中ＨＰＶ１６Ｅ６、Ｅ７亚基因的分布是不均一的，ｐ５３基因外显子７的改变并不常见。在实验中我们还建立了使用生物素标记的ｄＵＴＰ进行ＰＣＲ－ＳＳＣＰ的技术。     

Conserved genetic findings in metastatic bladder cancer: a possible utility of allelic loss of chromosomes 9p21 and 17p13 in diagnosis

CONTEXT: Molecular analysis of microsatellite alterations of biologically distinct tumor cell subpopulations from the same patient may aid in the determination of tumor origin and further our understanding of the genetic basis of cancer progression. DESIGN: The authors examined the pattern of allelic loss with polymorphic microsatellite markers on chromosome 9p21 (D9S161, D9S171, IFNA), regions of putative tumor suppressor gene p16, and on chromosome 17p13 (TP53), the p53 locus, in matched primary and metastatic bladder cancers from 9 patients. All patients underwent cystectomy for bladder cancer and had regional lymph node metastases at the time of surgery. Genomic DNA was prepared from primary cancers and matched synchronous lymph node metastases using a microdissection method. RESULTS: The overall frequency of allelic loss was 78% in primary cancer and 89% in paired metastatic cancer. The frequency of allelic loss in the primary cancer was 86% with D9S161, 67% with D9S171, 71% with IFNA, and 80% with TP53. The frequency of allelic loss in matched metastatic cancer was 100% with D9S161, 62% with D9S171, 71% with IFNA, and 80% with TP53. An identical pattern of allelic imbalance (allelic loss or retention) at multiple DNA loci was observed in matched primary and metastatic carcinoma in 8 (88%) cases. One case showed allelic loss in the metastasis, but not in the primary cancer. CONCLUSIONS: The pattern of allelic loss at chromosome 9p21 (p16) and 17p13 (p53) was generally maintained during cancer progression to metastasis, and identical allelic loss in primary cancer was conserved in paired metastatic carcinoma. These data suggest that these genetic changes may be useful in establishing a diagnosis and determining tumor origins in difficult cases.     

Cytokeratin 7 and cytokeratin 20 in primary urinary bladder carcinoma and matched lymph node metastasis.

BACKGROUND:-Cytokeratin 7 (CK7) and cytokeratin 20 (CK20) are 2 types of intermediate filament protein. Expression of CK7 is seen in the majority of primary urinary bladder carcinomas. CK20 is restricted to superficial and occasional intermediate cells of the normal urothelium of the bladder. Aberrant CK20 expression has been documented in urothelial carcinoma and has proved useful as an ancillary diagnostic aid for urinary bladder tumor. Our hypothesis is that the pattern of CK7 and CK20 expression in metastatic urothelial carcinoma duplicates the expression of the same markers in the primary tumors. Therefore, immunohistochemical staining of metastatic tumors for these 2 markers may be helpful for differential diagnosis in ambiguous metastatic tumor deposits. OBJECTIVE:-To determine the concordance of CK7 and CK20 expression in primary bladder urothelial carcinoma and the matched lymph node metastasis. DESIGN:-We studied 26 patients with lymph node metastases who underwent radical cystectomy and bilateral lymphadenectomy for bladder carcinoma. Immunohistochemical staining for CK7 and CK20 was performed on formalin-fixed paraffin-embedded tissues containing primary cancers and lymph node metastases. RESULTS:-In all cases, there was a concordant expression of CK20 in the primary cancer and its matched lymph node metastasis. Twelve cases (46%) showed positive CK20 immunoreactivity in the primary tumor and its matched lymph node metastases, whereas 14 cases (54%) were negative for CK20 in both the primary tumor and lymph node metastasis. All cases showed positive CK7 immunoreactivity in the primary cancers and matched lymph node metastases. CONCLUSIONS:-CK20 immunoreactivity is reliably observed in metastases from bladder cancer when the primary tumor expresses CK20.     

ERBB2 kinase domain mutation in a gastric cancer metastasis

ERBB2 is a member of the epidermal growth factor receptor (EGFR) family. Recent studies revealed that the kinase domain of the ERBB2 gene was mutated in human cancers, including gastric cancer. Despite the importance of cancer metastasis in the pathogenesis of cancers, data on the ERBB2 kinase domain mutation in cancer metastasis are lacking. In this study, to explore the possibility that ERBB2 mutation is involved in the metastasis mechanism, we analyzed the kinase domain of ERBB2 for the detection of somatic mutations in 58 gastric adenocarcinomas with lymph node metastasis. We found one ERBB2 mutation, which was detected in the lymph node metastasis, but not in the primary tumor of the same patient. The ERBB2 mutation was a missense mutation which substituted an amino acid in exon 21 (V832I). We simultaneously analyzed the somatic mutations of EGFR, K-RAS, PIK3CA and BRAF genes in the sample with the ERBB2 mutation, and found that this metastatic carcinoma did not harbor any of the mutations. Our data suggest that ERBB2 kinase domain mutation occasionally occurs in metastatic gastric carcinoma and might play a role in the metastatic process of some gastric carcinomas.     

Detection of aberrations of 17p and p53 gene in gastrointestinal cancers by dual (two-color) fluorescence in situ hybridization and GeneChip p53 assay

We performed dual (two-color) fluorescence in situ hybridization (FISH) using direct fluorescent labeling probes for p53 and chromosome 17 in six gastrointestinal (3 stomach and 3 colon) cancers. In three of these (1 stomach and 2 colon) the interphase cell nuclei showed an imbalance of signals for the p53 and chromosome 17; that is, the p53 signal count was lower than the chromosome 17 signal count, indicating deletion of the p53 gene. Moreover, metaphase FISH analysis demonstrated that those nuclei actually had a chromosome 17 with deletion of the p53 gene. Interestingly, these three cases had an abnormal chromosome 17 copy number, that is, chromosome 17 aneusomy. Furthermore, to investigate the possibility of p53 mutation in tumors with an imbalance of signals for chromosome 17 and p53 per nucleus, we performed a GeneChip p53 assay which has recently been developed. GeneChip p53 assay demonstrated that a primary tumor sample from one colon cancer case had a heterozygous point mutation of CGT (Arg) to CAT (His) at codon 273 in exon 8. In addition, a sample of metastatic tumor in the liver from the same case revealed two heterozygous point mutations. One of them was the same mutation as that is the primary tumor; the other was GTG (Val) to GGG (Gly) at codon 217 in exon 6. In conclusion, we found that the combination of dual-color FISH and GeneChip p53 assay offered reliable results and important information concerning not only deletion of the p53 gene and chromosome 17 aneusomy but also p53 mutations. Using these techniques, we demonstrated that an imbalance of signals for chromosome 17 and p53 per nucleus, chromosome 17 aneusomy, and accumulation of p53 mutations had occurred during carcinogenesis and development of gastrointestinal cancers.     

Molecular and immunohistochemical analysis of p53 mutations in scrapings and tissue from preinvasive and invasive breast cancer

 Mutations of the p53 gene appear to be one of the most common abnormalities in human cancer. Although many studies have been published about p53 alterations in breast cancer, data on molecular biological detection of p53 mutations in in situ lesions are still rare, and the implications for breast cancerogenesis are unclear. Tissue samples from 83 patients with different stages of breast cancer and from 13 patients with benign breast lesions were screened for p53 gene mutations by polymerase chain reaction (PCR) followed by temperature-gradient gel electrophoresis (TGGE). p53 protein accumulation was analysed by immunohistochemistry (IHC). Samples were gained from fresh-frozen tissue, scrapings, or paraffin embedded tissue. Additionally, 23 pairs of primary tumours and corresponding lymph nodes were examined. p53 gene aberrations were found in 55.7% of the infiltrating carcinomas, in 31.5% of the ductal carcinomas in situ (DCIS) and in one atypical ductal hyperplasia. A positive correlation was seen with high-grade tumours and with comedo. There was no statistically significant relationship with respect to age, menopausal status, tumour size, hormone receptor status or lymphatic invasion. Concordance between TGGE and IHC was seen in only 63% of the cases analysed. However, with regard to p53 mutation screening by TGGE, a high significance (P = 0.0008) was seen between standard tissue extraction and our scrape preparation technique. Among 8 pairs of primary tumours and their corresponding lymph node metastases, only 3 harbored identical p53 mutations in the same exon, while in 5 cases with mutant p53 in the primaries, no mutation was seen in the lymph node. Our data indicate that p53 mutations are frequent in breast tumours associated with unfavorable prognosis, including high-grade or the comedo histotype. There is evidence that p53 gene alterations occur early in breast cancerogenesis, as mutations were detected not only in in situ carcinomas but also in atypical ductal hyperplasia. Received: 14 April 1997 / Accepted 20 May 1997     

结直肠癌患者BRAF,KRAS,NRAS和PIK3CA基因突变与其病理正的关系

目的:探讨265例结直肠癌患者BRAF,KRAS,NRAS和PIK3 CA基因突变及其病理特征关系.方法:选取2014年12月至2016年12月的265例结直肠癌患者肿瘤组织标本进行回顾性分析,采用PCR扩增-直接测序法检测BRAF基因(1 5外显子600密码子),KRAS基因(12,13,61密码子突变),NRAS(2号与3号外显子的12密码子、13密码子与61密码子常见的12个突变位点)及PIK3 CA(第9,20外显子)基因的突变状态,分析其与结直肠癌临床病理特征的关系.结果:265例患者中存在BRAF基因突变率为6.8％(18/265),KRAS基因突变率为32.1％(85/265),NRAS基因突变率为5.7％(15/265),PIK3 CA基因突变率为11.3％(30/265).NRAS基因和KRAS基因突变与年龄有关(P＜0.05),与性别、原发部位、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关(P＞0.05);BRAF,PIK3 CA基因在原发部位为右半结肠患者中的突变率明显升高(P＜0.05),但与年龄、性别、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关(P＞0.05).结论:NRAS,PIK3 CA基因在中国结直肠癌患者中的突变率较低.KRAS,NRAS基因突变与年龄相关,BRAF,PIK3 CA基因与肿瘤原发部位相关,联合检测这些基因的突变情况可以判断疾病的发生发展.     

Coexpression of MUC1 with p53 or MUC2 correlates with lymph node metastasis in colorectal carcinomas

The alteration of the mucin profile have been known to play a role in colorectal carcinogenesis. MUC1 is up-regulated and MUC2 is down-regulated in colorectalcarcinomas. Overexpression of p53 is frequently noted in colorectal carcinomas with deep invasion or lymph node metastasis. However, there have been few reports about the association between MUC1, MUC2, and p53 expression with respect to the metastatic potential. This study was aimed to investigate the relationship of MUC1, MUC2, and protein p53 expressions with clinicopathological factors in colorectal carcinomas. Expressions of MUC1, MUC2, and p53 protein were examined immunohistochemically. Of total 97 cancers, 44 (45%) were MUC1 positive, 39 (40%) were MUC2 positive and 58 (59%) showed a p53 overexpression. Coexpression of MUC1 with p53 and dual expression of MUC1 with MUC2 were associated with a higher frequency of lymph node metastasis (p<0.05). The right colon showed a higher MUC1 positivity and frequent lymph node metastasis than the left colon (p<0.05). These results suggest that the coexpression of MUC 1 with p53 or MUC2 are involved in regional lymph node metastasis in colorectal carcinomas. The high expression of MUC1 in the right colon cancer was revealed to relate with lymph node metastasis.