p53 mutations in ovarian tumors, detected by temperature‐gradient gel electrophoresis, direct sequencing and immunohistochemistry

Abstract

Samples from 94 ovarian tumors, comprising 24 cystadenomas/adenofibromas, among them 6 benign and 18 borderline tumors, one benign Brenner tumor, 39 carcinomas, 17 sex-cord stromal tumors, 5 germ-cell tumors and 8 metastatic or recurrent neoplasms were screened for p53 aberrations by polymerase chain reaction (PCR), temperature-gradient gel electrophoresis (TGGE), direct sequencing and immunohistochemistry. All sex-cord stromal and germ-cell tumors showed wild-type p53, except for a heterozygous silent germ-line mutation in one androblastoma. Somatic p53 mutations were detected in only one tumor of the cystadenoma/adenofibroma series (4.2%), in contrast to 38.5% of the carcinomas, among them 57.1% of serous papillary carcinomas, and 12.5 to 22.2% of endometrioid and mucinous carcinomas. By direct sequencing, the mutations of 13 cases were qualified as mis-sense mutations (n = 10), or 1 to 2-bp deletions (n = 3). Only 2 cases were immunohistochemically positive in the absence of detectable p53-gene abnormalities. The presence of p53 aberrations was significantly correlated with high grade, but not with stage of disease. For 21 bilateral tumors and/or tumors spread to the peritoneum, samples from both ovaries and/or ascites were analyzed. Among these, 16 cases were identical as to the p53 genotype, 5 cases showed discordant p53 states in ovary and/or in ascites DNA. We conclude that somatic p53 mutations are very frequent in serous papillary carcinomas, particularly in tumors of high grade, bilaterality, and peritoneal spread, less frequent in other carcinoma types and extremely rare in borderline and benign tumors of the ovary.

A review of p53 expression and mutation in human benign, low malignant potential, and invasive epithelial ovarian tumors

“…For 10 studies (155 tumors; 36%), detailed information regarding tumor type was not provided. 17,19,21,24,26,27,32,33,36,38 In total, p53 was detected in 30 of 431 benign tumors (7%; 95% CI, 5-10%). Approximately 55% of the tumors were tested with the antibody D0-7, 23% were tested with PAb-1801, and the remaining 22% were tested with other antibodies (including D0-1, CM-1, BP53-12, Ab-6, and multiple antibodies).…”

“…17 122,131,132 In the majority of the studies, the tumors initially were screened for mutations using a combination of polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) 17 93 temporal temperature gradient electrophoresis, 135 constant denaturant gel electrophoresis, 58 and denaturing gradient gel electrophoresis 58 ), chemical mismatch cleavage, 128 and heteroduplex analysis. 89 DNA sequencing was used exclusively in 4 studies, 26 …”

“…The exons screened varied across studies (exons 5-8 in 14 studies; 26,36,42,48,58,59,93,103,116,119,127,131,132,134 exons 5-9 in 9 studies; 78 135 ). Among those studies in which exons 5-8 or exons 5-9 were evaluated, the p53 mutation prevalence estimates were similar: 42% (95% CI, 38 -46%) and 43% (95% CI, 47-59%), respectively.…”

“…The distribution of p53 mutations based on FIGO stage and based on tumor grade was described in 24 studies 26,36,42,50,53,58,81,82,84,92,95,103,115,[117][118][119][120][121]123,125,126,131,132,134 and 12 studies, 17,26,36,42,50,81,82,84,115,117,131,134 respectively. The mutation prevalence was higher among Stage III/IV tumors (49%) compared with Stage I/II tumors (31%) (Fig.…”

Molecular genetic analysis of ovarian serous cystadenomas

“…14,19 In order to elucidate the mechanisms of serous carcinogenesis, specifically the molecular genetic alterations in early tumorigenesis, we undertook a study of serous cystadenomas aimed at assessing whether mutations of BRAF and KRAS, which are common in serous borderline tumors and low-grade serous carcinomas are present in serous cystadenomas. 6,[19][20][21] In addition, we determined the clonality of serous cystadenomas by analyzing the patterns of X-chromosome inactivation of the X-linked androgen receptor (HUMARA) gene. For molecular genetic analyses, we have applied a new method to isolate pure and abundant cyst-lining epithelial cells from fresh serous cystadenomas.…”