Immunoexpression and prognostic role of p53 in different subtypes of epithelial ovarian carcinoma

We sought to investigate the significance of p53 expression for epithelial ovarian carcinoma.In this study,we used immunohistochemical method to investigate the expression patterns of p53 in different subtypes of epithelial ovarian carcinoma.We found that the expressions of p53 protein in epithelial ovarian cancer(pituita,serosity and intima) were 88.9%,75% and 100%,respectively,while the recurrence rates among three cancer subtypes were significantly different(33.3%,12.5% and 0%,respectively;P 0.05).Compared with patients without lymph node metastasis,the expression of p53 in patients with lymph node metastasis was significantly strong(68.75% and 100%,respectively;P 0.05).However,the recurrence rate in the patients with lymph node metastasis(40%) was higher than that without lymph node metastasis(6.25%,P 0.05).The expressions of p53 protein in ovarian cancer betweenⅠ-Ⅱ(25%) stage and Ⅱ-Ⅳ stage(100%) were significantly different(P 0.05),and the recurrence rates between the two groups were significantly different(0% and 31.25%,respectively,P 0.05).Therefore,p53 protein has an intimate relationship with the malignant degree and the prognosis of ovarian cancer.     

p53 Expression,mutation, and allelic deletion in ovarian cancer

The aim of this investigation was to study the prevalence of p53 gene mutations and allelic deletions in ovarian cancer and the relationship between these events and p53 expression. Genomic p53 was amplified by the polymerase chain reaction (PCR) from paraffin-embedded sections of tumour and non-tumour tissue. Exons 5–9 were screened for mutations using non-isotopic single-strand conformation polymorphism (SSCP) analysis. Allelic deletions at a sequence polymorphism in exon 4 were studied for loss of heterozygosity (LOH) by restriction analysis and by SSCP. p53 expression was detected by immunohistochemistry with the p53 antibodies CM1 and Do7. Of 44 cases, ten (23 per cent), including a mucinous tumour of low malignant potential, showed mutations. There was a statistically significant correlation between p53 mutation and expression (P<0·01) but seven cases showed discordance. Of 18 informative cases, eight (44 per cent) demonstrated LOH. Mutations were identified in three of the informative cases, two of which also had LOH. The remaining case showed mutations in two amplicons. p53 dysfunction, as indicated by mutation, deletion, or increased expression, is common in ovarian cancer. There is an association between these molecular events but the exact mechanisms of p53 inactivation remain to be elucidated.     

上皮性卵巢癌中IRSp53的表达及其临床意义

目的探讨胰岛素受体底物p53蛋白(insulin receptor substrate p53,IRSp53)在上皮性卵巢癌(epithelial ovarian cancer,EOC)中的表达,及其与临床病理特征、预后之间的关系。方法采用免疫组化SP法和Western blot法检测不同病理类型卵巢组织中IRSp53的表达。结果 IRSp53在EOC中的阳性率为62.82%,显著高于正常卵巢(4.55%)、良性卵巢肿瘤(18.75%)及交界性卵巢肿瘤(26.67%)(P0.05)。IRSp53在EOC中的表达与患者血清CA125水平、FIGO分期、分化程度及术后肿瘤残余直径相关(P0.05)。IRSp53在EOC、正常卵巢、良性卵巢肿瘤和交界性卵巢肿瘤中的表达分别为1.203±0.080、0.240±0.050、0.308±0.354和0.467±0.135,差异有统计学意义(P0.05)。IRSp53高表达的EOC患者总生存期明显低于IRSp53低表达的患者(P0.05)。结论 IRSp53在EOC中高表达,IRSp53高表达与患者的不良预后相关,提示IRSp53可能在EOC的发生、发展中发挥重要作用。     

Distribution of p53 expression in tissue from 774 Danish ovarian tumour patients and its prognostic significance in ovarian carcinomas

The clinical roles played by normal and altered p53 in cancer are under intensive investigation, but larger studies describing the pattern as well as the prognostic value are still needed. The aim of this study was, using tissue array (TA), to examine the overexpression of p53 protein in 774 epithelial ovarian tumour tissues from Danish women and to evaluate whether p53 tissue expression levels correlate with clinicopathological parameters and prognosis. The distribution of p53 expression levels at different stages of disease, in different histological subtypes, and the prognostic value of p53 tissue expression were examined. Overall, p53 was expressed in 24/189 (13%) low malignant potential ovarian tumours (LMP) and in 278/585 (48%) ovarian cancers (OC). No significant difference in frequency of p53 tissue expression in LMP tissue was noted with increasing tumour stage (p=0.98). By contrast, there was a significant increase in the frequency of p53 tissue expression in OC with increasing FIGO stage (p<0.00001). Multivariate Cox regression analysis found that less than 20% tissue expression of p53 was associated with longer OC disease-specific survival. Tissue p53 expression may be of prognostic value in women with OC.     

Distinct evolutionary trajectories of primary high‐grade serous ovarian cancers revealed through spatial mutational profiling

High‐grade serous ovarian cancer (HGSC) is characterized by poor outcome, often attributed to the emergence of treatment‐resistant subclones. We sought to measure the degree of genomic diversity within primary, untreated HGSCs to examine the natural state of tumour evolution prior to therapy. We performed exome sequencing, copy number analysis, targeted amplicon deep sequencing and gene expression profiling on 31 spatially and temporally separated HGSC tumour specimens (six patients), including ovarian masses, distant metastases and fallopian tube lesions. We found widespread intratumoural variation in mutation, copy number and gene expression profiles, with key driver alterations in genes present in only a subset of samples (eg PIK3CA, CTNNB1, NF1). On average, only 51.5% of mutations were present in every sample of a given case (range 10.2–91.4%), with TP53 as the only somatic mutation consistently present in all samples. Complex segmental aneuploidies, such as whole‐genome doubling, were present in a subset of samples from the same individual, with divergent copy number changes segregating independently of point mutation acquisition. Reconstruction of evolutionary histories showed one patient with mixed HGSC and endometrioid histology, with common aetiologic origin in the fallopian tube and subsequent selection of different driver mutations in the histologically distinct samples. In this patient, we observed mixed cell populations in the early fallopian tube lesion, indicating that diversity arises at early stages of tumourigenesis. Our results revealed that HGSCs exhibit highly individual evolutionary trajectories and diverse genomic tapestries prior to therapy, exposing an essential biological characteristic to inform future design of personalized therapeutic solutions and investigation of drug‐resistance mechanisms. © 2013 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

TP53 mutations in serous tubal intraepithelial carcinoma and concurrent pelvic high-grade serous carcinoma--evidence supporting the clonal relationship of the two lesions

Serous tubal intraepithelial carcinomas (STICs) have been proposed to be the most likely precursor of ovarian, tubal and 'primary peritoneal' (pelvic) high-grade serous carcinoma (HGSC). As somatic mutation of TP53 is the most common molecular genetic change of ovarian HGSC, occurring in more than 95% of cases, we undertook a mutational analysis of 29 pelvic HGSCs that had concurrent STICs to demonstrate the clonal relationship of STICs and HGSCs. In addition, we correlated the mutational data with p53 immunostaining to determine the role of p53 immunoreactivity as a surrogate for TP53 mutations in histological diagnosis. Somatic TP53 mutations were detected in all 29 HGSCs analysed and the identical mutations were detected in 27 of 29 pairs of STICs and concurrent HGSCs. Missense mutations were observed in 61% of STICs and frameshift/splicing junction/nonsense mutations in 39%. Interestingly, there were two HGSCs with two distinctly different TP53 mutations each, but only one of the mutations was detected in the concurrent STICs. Missense mutations were associated with intense and diffuse (≥ 60%) p53 nuclear immunoreactivity, while most of the null mutations were associated with complete loss of p53 staining (p < 0.0001). Overall, this p53 staining pattern yielded a sensitivity of 87% and a specificity of 100% in detecting TP53 missense mutations. In conclusion, the above findings support the clonal relationship of STIC and pelvic HGSC and demonstrate the utility of p53 immunostaining as a surrogate for TP53 mutation in the histological diagnosis of STIC. In this regard, it is important to appreciate the significance of different staining patterns. Specifically, strong diffuse staining correlates with a missense mutation, whereas complete absence of staining correlates with null mutations.     

miR-141-3p对卵巢癌的作用及其机制

目的:探究miR-141-3p在卵巢癌中的作用及其相关的分子机制.方法:实时荧光定量PCR检测30例卵巢囊肿和30例卵巢癌组织中miR-141-3p和表皮生长因子受体(EGFR)的表达水平.将SKOV3细胞分为NC组(无转染的SKOV3细胞),miR-141-3p组(SKOV3细胞转染miR-141-3p),LV-EG...     

肿瘤干细胞与卵巢癌

卵巢肿瘤干细胞（OCSCs)是存在于卵巢癌组织中的一类具有自我更新和多向分化潜能的细胞,表面共表达CD44和CD117分子标记。虽然其起源不是很确定,但目前倾向于认为卵巢表面上皮细胞来源于OCSCs。研究OCSCs自我更新机制和表观遗传学的改变,可为肿瘤发生的机制及新药的开发提供很好的基础     

p53基因与顺铂联合作用对人卵巢癌细胞的杀伤效果

目的 :探讨外源性p5 3基因转染对人卵巢癌细胞系SKOV 3的生物学行为影响及与顺铂联合作用后对人卵巢癌细胞的杀伤效果。方法 :用脂质体介导的转染技术 ,将p5 3基因的真核细胞表达载体 (PcDNA p5 3)导入不表达p5 3的人卵巢癌SKOV 3细胞中 ,经G4 18筛选 ,Northernblot及Westernblot鉴定后 ,观察其对细胞生物学行为的影响及与顺铂联合作用后对细胞集落形成的影响。结果 :转染后获得稳定表达p5 3的转染克隆。外源性p5 3基因的表达明显抑制了卵巢癌细胞的生长及集落形成能力 ,使细胞阻滞于G1 期 ,并增加了卵巢癌细胞对顺铂的敏感性。结论 :外源性野生型p5 3基因能抑制卵巢癌细胞的生长 ,与顺铂联合作用后增强了对人卵巢癌细胞的杀伤效果。     

野生型p53基因转染卵巢癌SKOV-3细胞对化疗药物顺铂敏感性的影响

目的 研究野生型p53基因转染卵巢癌SKOV－3细胞对化疗药物顺铂敏感性的影响。方法 用脂质体介导的转染技术，将含有全长人野生型p53 cDNA的真核表达重组质粒分别导入受不同浓度顺铂作用的SKOV－3培养细胞中，观察p53不同状态下对肿瘤细胞化疗敏感性的差异。结果 转染p53基因后的SKOV－3细胞集落形成率与未转染的SKOV－3细胞相比，抑制率为56．4％。用0.5μg/ml顺铂分别作用24h、48h后，集落形成数分别下降了76．2％、84．1％；用1μg/ml顺铂分别作用24h、48h后，集落形成数分别下降了89．5％、93．7％。转染p53基因后，肿瘤细胞S期和G2／M期的比例下降，G1／G0期的比例增加，p53基因的转染使卵巢癌细胞发生G1期阻滞。结论 外源性野生型p53基因的转染增加了卵巢癌SKOV－3细胞对化疗药顺铂的敏感性。     

卵巢癌中k-ras 基因点突变及p53蛋白表达

目的 探讨k—ras基因点突变和p53蛋白表达在卵巢癌发生中的作用及致癌机制。方法 采用显微切割技术、半巢式PCR—RFLP技术和免疫组化染色检测55例卵巢癌及其交界性病变中的k—ras基因点突变和p53蛋白表达。结果 k-ras基因点突变率在黏液性腺癌(61．9％)明显高于浆液性腺癌(14．2％),在黏液性交界性腺瘤(61．5％)明显高于浆液性交界性腺瘤(12．5％)。p53蛋白表达率在浆液性腺癌(80％)明显高于黏液性腺癌(52％),并随组织学分级而增高。结论 黏液性腺癌主要通过腺瘤-交界性腺瘤-腺癌途径致癌,k—ms基因点突变是黏液性腺癌的早期事件,黏液性交界性腺瘤是黏液性腺癌的癌前病变。浆液性腺癌主要通过生发上皮直接恶性转化形成,p53蛋白表达在浆液性腺癌的发生中起重要作用,是浆液性腺癌的晚期事件。     

Precursor lesions of ovarian epithelial malignancy

Most ovarian carcinomas arise from the mesothelial surface lining of the ovaries, or from invaginations of this lining into the superficial ovarian cortex to form cortical inclusion cysts. The native ovarian surface mesothelium is of an 'uncommitted' phenotype, and has potential to modulate to epithelial or mesenchymal phenotypes in response to signals such as those associated with ovulation. The exposure of the mesothelial lining of an inclusion cyst to the ovarian stromal microenvironment may be responsible for the phenotypic change to Müllerian epithelium so commonly seen in these cysts. Müllerian metaplasia is usually to a serous phenotype, and it is possible that undefined molecular events occurring in an inclusion cyst that has undergone Müllerian metaplasia may initiate neoplastic change in these cysts. This may be the developmental pathway of most invasive serous carcinomas. Occasional rare cases of ovarian intraepithelial neoplasia, manifested by epithelial atypia in an inclusion cyst or on the surface epithelium without invasive carcinoma, are identified histologically. Serous borderline tumours represent a separate category and in most cases probably do not progress to frank carcinoma. Mucinous carcinomas may in some cases have arisen from pre-existing benign and borderline mucinous tumours. Endometriosis of the ovary is associated with genetic abnormalities and is frequently found in association with clear cell and endometrioid carcinomas, suggesting that in many cases these latter two types of carcinoma may have arisen directly from endometriotic deposits. Ovaries removed prophylactically from women with a family history of ovarian carcinoma or with a mutation in one of the genes predisposing to ovarian carcinoma should be processed in their entirety, and examined closely not just for obviously neoplastic lesions, but also for more subtle morphological abnormalities of the surface epithelium or the epithelium lining cortical inclusion cysts.     

上皮性卵巢癌中Cyclin D1和p27的表达及其临床意义

目的探讨Cyclin D1和p27蛋白在上皮性卵巢癌中的表达及其与临床病理间的关系。方法利用免疫组化S-P法测定Cyclin D1和p27蛋白在62例上皮性卵巢癌中的表达,比较Cyclin D1、p27蛋白与卵巢癌的各项临床病理指标间的关系及两者间的关系。结果在上皮性卵巢癌中,Cyclin D1蛋白的表达在FIGO分期Ⅰ-Ⅱ期低于Ⅲ-Ⅳ期,组织学G1-G2组低于G3组,术后残留癌组织≤2cm组低于〉2cm组,淋巴无转移组低于有转移组;而p27蛋白在FIGO分期Ⅰ-Ⅱ期高于Ⅲ-Ⅳ期,组织学G1-G2组高于G3组,淋巴无转移组高于有转移组,以上各组间均有统计学差异（P〈0.05）;在上皮性卵巢癌中Cyclin Dl、p27蛋白的表达呈负相关（rs=-0.255,P〈0.05）。结论CyclinDl、p27蛋白的异常表达可能与上皮性卵巢癌的发展及恶性程度有关,可作为评估上皮性卵巢癌恶性程度和预后的指标。     

溶血磷脂酸与卵巢肿瘤

溶血磷脂酸是一种具有细胞间信号传导作用的脂类小分子物质，具有广泛的生物学效应。研究发现卵巢癌患者的腹水中存在溶血磷脂酸，它可以促进癌细胞的生长；卵巢癌患者的血浆中具有明显高于正常对照组的溶血磷脂酸，用于卵巢癌的诊断具有较高的敏感性及特异性。优于Ca125。卵巢癌的细胞呆分泌溶血磷脂酸，且细胞中存在溶血磷脂酸的自分泌环，它与肿瘤的发展，耐药及预后密切相关。这将对卵巢癌的治疗提供新的可能。     

Analysis of RAD51C germline mutations in high-risk breast and ovarian cancer families and ovarian cancer patients

There is strong evidence that overtly inactivating mutations in RAD51C predispose to hereditary breast and ovarian cancer but the prevalence of such mutations, and whether they are associated with a particular clinical phenotype, remains unclear. Resolving these questions has important implications for the implementation of RAD51C into routine clinical genetic testing. Consequently, we have performed a large RAD51C mutation screen of hereditary breast and ovarian cancer families, and the first study of unselected patients diagnosed with ovarian cancer. Our data confirm a consistent but low frequency (2/335 families) of inactivating RAD51C mutations among families with a history of both breast and ovarian cancer and an absence of mutations among breast cancer only families (0/1,053 families). Our data also provide support for the designation of the missense variant p.Gly264Ser as a moderate penetrance allele.     

Epithelial ovarian cancer risk: A review of the current genetic landscape

Ovarian cancer is the fourth most common cause of cancer-related death in women in the developed world, and one of the most heritable cancers. One of the most significant risk factors for epithelial ovarian cancer (EOC) is a family history of breast and/or ovarian cancer. Combined risk factors can be used in models to stratify risk of EOC, and aid in decisions regarding risk-reduction strategies. Germline pathogenic variants in EOC susceptibility genes including those involved in homologous recombination and mismatch repair pathways are present in approximately 22% to 25% of EOC. These genes are associated with an estimated lifetime risk of EOC of 13% to 60% for BRCA1 variants and 10% to 25% for BRCA2 variants, with lower risks associated with remaining genes. Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) thought to explain an additional 6.4% of the familial risk of ovarian cancer, with 34 susceptibility loci identified to date. However, an unknown proportion of the genetic component of EOC risk remains unexplained. This review comprises an overview of individual genes and SNPs suspected to contribute to risk of EOC, and discusses use of a polygenic risk score to predict individual cancer risk more accurately.     

A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high‐grade serous carcinoma development

Recent evidence suggests that ovarian high‐grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp–TAg transgenic mouse, which expresses the SV40 large T‐antigen (TAg) under the control of the mouse müllerian‐specific Ovgp‐1 promoter. Histological analysis of the fallopian tubes of mogp–TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal‐appearing p53‐positive epithelium that are similar to ‘p53 signatures’ in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non‐invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp–TAg and wild‐type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase IIα, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low‐grade and high‐grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as for developing novel approaches for the prevention, diagnosis and therapy of this disease. Published 2014. This article has been contributed to by US Government employees and their work is in the public domain in the USA.     

Tea polyphenols prevent lung from preneoplastic lesions and effect p53 and bcl-2 gene expression in rat lung tissues

Lung cancer is one of the cancers that have the highest incidence and the highest mortality rate, and it is of great interest to identify ways to prevent its occurrence. We had established an animal model by using 3,4-benzopyrene intra-pulmonary injection in our previous study, and had observed that the rats lung carcinoma incidence and multiplicity were significantly reduced by green tea administration. This study further investigated the effect of tea polyphenols on rat lung preneoplastic lesions using the lung carcinoma model established by 3,4-benzopyrene intra-pulmonary injection. Sprague–Dawley rats of the same age were randomly divided into 10 groups and treated with 3,4-benzopyrene by intra-pulmonary injection. Five groups were given 0.3% solution of tea polyphenols (equivalent to 1.2% of green tea) in drinking water, while the other 5 groups were given pure drinking water. The rats were sacrificed at 0, 1, 4, 8 and 16 weeks after carcinogen treatment. In the control groups of rats, local bronchial inflammation were observed at 1 week after 3,4-benzopyrene treatment. From 4 weeks to 16 weeks after carcinogen treatment, hyperplasia, cell hyperproliferation, heterogeneity were observed in the bronchial epithelium. Meanwhile, the expression of p53 mRNA and protein, as well as the level of bcl-2, increased in the bronchial epithelial lesion. Tea polyphenols treatment significantly alleviated the bronchial epithelial lesions. At the same time, tea polyphenols treatment enhanced p53 expression, but reduced bcl-2 expression. These results indicated that tea polyphenols may have preventive effect against lung preneoplasm lesions, possibly through regulating the expression of some critical genes such as p53 and bcl-2.     

p53 and erbB-2 are not associated in matched cases of primary and metastatic ovarian carcinomas

Ovarian cancer has a high mortality rate largely due to the limited number of ovarian carcinomas detected at an early stage. Understanding the molecular changes occurring during the progression of ovarian carcinoma would aid in the development of therapies that may inhibit or target metastasis. Primary and metastatic lesions from 54 and 40 patients with advanced ovarian carcinoma, respectively (including matched primary and metastatic lesions from 30 patients) were evaluated for nuclear accumulation of p53 (clone BP53-12-1) and cytoplasmic and membranous immunostaining of p185 erbB-2 (clone 3B5) by immunohistochemistry. No differences in the immunostaining of p53 and p185erbB-2 (cytoplasm or membrane) were observed between primary and metastatic lesions of the matched cases. Similarly, no differences in the proportion of positive cases of p53 between primary and metastatic lesions of the matched cases was observed. Thus, novel therapies that target p53 or p185erbB-2 can utilize specimens from either primary or metastatic lesions to characterize these targets prior to therapy. Spearman correlations between p53 and p185erbB-2 (cytoplasm or membrane) immunohistochemistry scores were insignificant for the matched cases, all primary lesions, and all metastatic lesions. Also, no significant associations occurred between nuclear accumulation of p53 (positive versus negative) and phenotypic expression of p185erbB-2 (cytoplasm or membrane) immunostaining scores for the matched cases, all primary lesions, and all metastatic lesions. Thus, the nuclear accumulation of p53 and immunostaining of p185erbB-2 in the cytoplasm or on the cellular membranes are independent.