The hereditary breast and ovarian cancer gene, BRCA1, encodes a large polypeptide that contains the cysteine-rich RING motif, a zinc-binding domain found in a variety of regulatory proteins. Here we describe a novel protein that interacts in vivo with the N-terminal region of BRCA1. This BRCA1-associated RING domain (BARD1) protein contains an N-terminal RING motif, three tandem ankyrin repeats, and a C-terminal sequence with significant homology to the phylogenetically conserved BRCT domains that lie near the C terminus of BRCA1. The BARD1/BRCA1 interaction is disrupted by BRCA1 missense mutations that segregate with breast cancer susceptibility, indicating that BARD1 may be involved in mediating tumour suppression by BRCA1.

BackgroundOvarian carcinomas consist of at least five distinct diseases: high-grade serous, low-grade serous, clear cell, endometrioid, and mucinous. Biomarker and molecular characterization may represent a more biologically relevant basis for grouping and treating this family of tumors, rather than site of origin. Molecular characteristics have become the new standard for clinical pathology, however development of tailored type-specific therapies is hampered by a failure of basic research to recognize that model systems used to study these diseases must also be stratified. Unrelated model systems do offer value for study of biochemical processes but specific cellular context needs to be applied to assess relevant therapeutic strategies.MethodsWe have focused on the identification of clear cell carcinoma cell line models. A panel of 32 “ovarian cancer” cell lines has been classified into histotypes using a combination of mutation profiles, IHC mutation-surrogates, and a validated immunohistochemical model. All cell lines were identity verified using STR analysis.ResultsMany described ovarian clear cell lines have characteristic mutations (including ARID1A and PIK3CA) and an overall molecular/immuno-profile typical of primary tumors. Mutations in TP53 were present in the majority of high-grade serous cell lines. Advanced genomic analysis of bona-fide clear cell carcinoma cell lines also support copy number changes in typical biomarkers such at MET and HNF1B and a lack of any recurrent expressed re-arrangements.Conclusions: As with primary ovarian tumors, mutation status of cancer genes like ARID1A and TP53 and a general immuno-profile serve well for establishing histotype of ovarian cancer cell We describe specific biomarkers and molecular features to re-classify generic “ovarian carcinoma” cell lines into type specific categories. Our data supports the use of prototype clear cell lines, such as TOV21G and JHOC-5, and questions the use of SKOV3 and A2780 as models of high-grade serous carcinoma.

Objectives Cell lines derived from human ovarian and endometrial cancers, and their immortalized non-malignant counterparts, are critical tools to investigate and characterize molecular mechanisms underlying gynecologic tumorigenesis, and facilitate development of novel therapeutics. To determine the extent of misidentification, contamination and redundancy, with evident consequences for the validity of research based upon these models, we undertook a systematic analysis and cataloging of endometrial and ovarian cell lines. Methods Profiling of cell lines by analysis of DNA microsatellite short tandem repeats (STR), p53 nucleotide polymorphisms and microsatellite instability. Results Fifty-one ovarian cancer lines were profiled with ten found to be redundant and five (A2008, OV2008, C13, SK-OV-4 and SK-OV-6) identified as cervical cancer cells. Ten endometrial cell lines were analyzed, with RL-92, HEC-1A, HEC-1B, HEC-50, KLE, and AN3CA all exhibiting unique, uncontaminated STR profiles. Multiple variants of Ishikawa and ECC-1 endometrial cancer cell lines were genotyped and analyzed by sequencing of mutations in the p53 gene. The profile of ECC-1 cells did not match the EnCa-101 tumor, from which it was reportedly derived, and all ECC-1 isolates genotyped as Ishikawa cells, MCF-7 breast cancer cells, or a combination thereof. Two normal, immortalized endometrial epithelial cell lines, HES cells and the hTERT-EEC line, were identified as HeLa cervical carcinoma and MCF-7 breast cancer cells, respectively. Conclusions Results demonstrate significant misidentification, duplication, and loss of integrity of endometrial and ovarian cancer cell lines. Authentication by STR DNA profiling is a simple and economical method to verify and validate studies undertaken with these models.

The interaction between medical research and for-profit corporations is not new, but it has expanded considerably in recent years. Some of the recent trends may accelerate the research process, particularly when large clinical trials are required. However, a renewed commitment to the application of high ethical standards is essential to ensure that societal trust in research is not eroded, subjects enrolled in trials do not become merely a means to an end, and medical research is efficiently translated into clinical advances that will benefit future patients. This article focuses on the analysis of conflicts of interest in the conduct of clinical trials in both academic and community-based settings. Specifically, it discusses how the roles of research scientists and clinical practitioners differ and the importance of ensuring that participants' consent to enroll in clinical trials is not the result of confusion about the goals of an experimental treatment that may resemble clinical care. The article also discusses the potential conflicts of interest that can arise when clinicians stand to gain from enrolling their own patients as subjects in clinical trials and examines various instances in which disclosure of information regarding funding and compensation may serve to minimize such conflicts. This article emphasizes that to preserve the integrity of research and to protect the welfare of human subjects who enroll in trials, physicians should have adequate training in the conduct of research and be familiar with the ethics of research. When a physician has treated or continues to treat a patient who is eligible to enroll as a subject in a clinical trial conducted by the same physician, someone other than the treating physician should obtain the participant's informed consent. Finally, the article addresses disclosure of financial incentives and related funding issues.

Overexpression of the imprinted insulin-like growth factor-II (IGF2) is a prominent characteristic of gynecologic malignancies. The purpose of this study was to determine whether IGF2 loss of imprinting (LOI), aberrant H19 expression, and/or epigenetic deregulation of the IGF2/H19 imprinted domain contributes to elevated IGF2 expression in serous epithelial ovarian tumors. IGF2 LOI was observed in 5 of 23 informative serous epithelial ovarian cancers, but this did not correlate with elevated expression of IGF2 H19 RNA expression levels were also found not to correlate with IGF2 transcript levels. However, we identified positive correlations between elevated IGF2 expression and hypermethylation of CCCTC transcription factor binding sites 1 and 6 at the H19 proximal imprint center (P = 0.05 and 0.02, respectively). Hypermethylation of CCCTC transcription factor sites 1 and 6 was observed more frequently in cancer DNA compared with lymphocyte DNA obtained from women without malignancy (P < 0.0001 for both sites 1 and 6). Ovarian cancers were also more likely to exhibit maternal allele-specific hypomethylation upstream of the imprinted IGF2 promoters when compared with normal lymphocyte DNA (P = 0.004). This is the same region shown previously to be hypomethylated in colon cancers with IGF2 LOI, but this was not associated with LOI in ovarian cancers. Elevated IGF2 expression is a frequent event in serous ovarian cancer and this occurs in the absence of IGF2 LOI. These data indicate that the epigenetic changes observed in these cancers at the imprint center may contribute to IGF2 overexpression in a novel mechanistic manner. (Mol Cancer Res 2006;4(4):283 -92)