Chromosomal losses of regions on 5q and lack of high-level amplifications at 8q24 are associated with favorable prognosis for ovarian serous carcinoma

The TIGD5 gene located in 8q24 and frequently amplified in ovarian cancers is a tumor suppressor

Ovarian cancer (OC) is the fifth most common cancer of female cancer death and leading cause of lethal gynecological cancers. High-grade serous ovarian carcinoma (HGSOC) is an aggressive malignancy that is rapidly fatal. Many cases of OC show amplification of the 8q24 chromosomal region, which contains the well-known oncogene MYC. Although MYC amplification is more frequently observed in OCs than in other tumor types, due to the large size of the 8q24 amplicon, the functions of the vast majority of the genes it contains are still unknown. The TIGD5 gene is located at 8q24.3 and encodes a nuclear protein with a DNA-binding motif, but its precise role is obscure. We show here that TIGD5 often co-amplifies with MYC in OCs, and that OC patients with high TIGD5 mRNA expression have a poor prognosis. However, we also found that TIGD5 overexpression in ovarian cancer cell lines unexpectedly suppressed their growth, adhesion, and invasion in vitro, and also reduced tumor growth in xenografted nude mice in vivo. Thus, our work suggests that TIGD5 may in fact operate as a tumor suppressor in OCs rather than as an oncogene.

The Molecular Landscape Influencing Prognoses of Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is one of the major increasing lethal malignancies of the gynecological tract, mostly due to delayed diagnosis and chemoresistance, as well as its very heterogeneous genetic makeup. Application of high-throughput molecular technologies, gene expression microarrays, and powerful preclinical models has provided a deeper understanding of the molecular characteristics of EOC. Therefore, molecular markers have become a potent tool in EOC management, including prediction of aggressiveness, prognosis, and recurrence, and identification of novel therapeutic targets. In addition, biomarkers derived from genomic/epigenomic alterations (e.g., gene mutations, copy number aberrations, and DNA methylation) enable targeted treatment of affected signaling pathways in advanced EOC, thereby improving the effectiveness of traditional treatments. This review outlines the molecular landscape and discusses the impacts of biomarkers on the detection, diagnosis, surveillance, and therapeutic targets of EOC. These findings focus on the necessity to translate these potential biomarkers into clinical practice.

Cyclin-dependent kinase 7 inhibitor THZ1 in cancer therapy

Current cancer therapies have encountered adverse response due to poor therapeutic efficiency, severe side effects and acquired resistance to multiple drugs. Thus, there are urgent needs for finding new cancer-targeted pharmacological strategies. In this review, we summarized the current understanding with THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), which demonstrated promising anti-tumor activity against different cancer types. By introducing the anti-tumor behaviors and the potential targets for different cancers, this review aims to provide more effective approaches to CDK7 inhibitor-based therapeutic agents and deeper insight into the diverse tumor proliferation mechanisms.

Targeting MYC dependency in ovarian cancer through inhibition of CDK7 and CDK12/13

High-grade serous ovarian cancer is characterized by extensive copy number alterations, among which the amplification of MYC oncogene occurs in nearly half of tumors. We demonstrate that ovarian cancer cells highly depend on MYC for maintaining their oncogenic growth, indicating MYC as a therapeutic target for this difficult-to-treat malignancy. However, targeting MYC directly has proven difficult. We screen small molecules targeting transcriptional and epigenetic regulation, and find that THZ1 - a chemical inhibiting CDK7, CDK12, and CDK13 - markedly downregulates MYC. Notably, abolishing MYC expression cannot be achieved by targeting CDK7 alone, but requires the combined inhibition of CDK7, CDK12, and CDK13. In 11 patient-derived xenografts models derived from heavily pre-treated ovarian cancer patients, administration of THZ1 induces significant tumor growth inhibition with concurrent abrogation of MYC expression. Our study indicates that targeting these transcriptional CDKs with agents such as THZ1 may be an effective approach for MYC-dependent ovarian malignancies.

Long non-coding RNAs in ovarian cancer

Long non-coding RNAs (lncRNAs) refer to functional cellular RNAs molecules longer than 200 nucleotides in length. Unlike microRNAs, which have been widely studied, little is known about the enigmatic role of lncRNAs. However, lncRNAs have motivated extensively attention in the past few years and are emerging as potentially important regulators in pathological processes, including in cancer. We now understand that lncRNAs play role in cancer through their interactions with DNA, protein, and RNA in many instances. Moreover, accumulating evidence has recognized that large classes of lncRNAs are functional for ovarian cancer. Nevertheless, the biological phenomena and molecular mechanisms of lncRNAs in ovarian cancer remain to be better identified. In this review, we outline the dysregulated expression of lncRNAs and their potential clinical implications in ovarian cancer, with a particular emphasis on discussing the well characterized mechanisms underlying lncRNAs in ovarian cancer.

Genomic/Epigenomic Alterations in Ovarian Carcinoma: Translational Insight into Clinical Practice

Ovarian carcinoma is the most lethal gynecological malignancy worldwide. Recent advance in genomic/epigenomic researches will impact on our prevention, detection and intervention on ovarian carcinoma. Detection of germline mutations in BRCA1/BRCA2, mismatch repair genes, and other genes in the homologous recombination/DNA repair pathway propelled the genetic surveillance of most hereditary ovarian carcinomas. Germline or somatic mutations in SMARCA4 in familial and sporadic small cell carcinoma of the ovary, hypercalcemia type, lead to our recognition on this rare aggressive tumor as a new entity of the atypical teratoma/rhaboid tumor family. Genome-wide association studies have identified many genetic variants that will contribute to the evaluation of ovarian carcinoma risk and prognostic prediction. Whole exome sequencing and whole genome sequencing discovered rare mutations in other drive mutations except p53, but demonstrated the presence of high genomic heterogeneity and adaptability in the genetic evolution of high grade ovarian serous carcinomas that occurs in cancer progression and chemotherapy. Gene mutations, copy number aberrations and DNA methylations provided promising biomarkers for the detection, diagnosis, prognosis, therapy response and targets of ovarian cancer. These findings underscore the necessity to translate these potential biomarkers into clinical practice.

Kinesin family member 14 in human oral cancer: A potential biomarker for tumoral growth

Kinesin family member 14 (KIF14), a microtubule-based motor protein, plays an important role in chromosomal segregation, congression, and alignment. Considerable evidence indicates that KIF14 is involved in cytokinesis, although little is known about its role in oral squamous cell carcinomas (OSCCs). In the current study, we functionally and clinically investigated KIF14 expression in patients with OSCC. Quantitative reverse transcriptase–polymerase chain reaction and immunoblotting analyses were used to assess the KIF14 regulatory mechanism in OSCC. Immunohistochemistry (IHC) was performed to analyze the correlation between KIF14 expression and clinical behavior in 104 patients with OSCC. A KIF14 knockdown model of OSCC cells (shKIF14 cells) was used for functional experiments. KIF14 expression was up-regulated significantly (P<0.05) in OSCCs compared with normal counterparts in vitro and in vivo. In addition, shKIF14 cells inhibited cellular proliferation compared with control cells by cell-cycle arrest at the G2/M phase through up-regulation of G2 arrest-related proteins (p-Cdc2 and cyclin B1). As expected, IHC data from primary OSCCs showed that KIF14-positive patients exhibited significantly (P<0.05) more larger tumors compared with KIF14-negative patients. The current results suggest for the first time that KIF14 is an indicator of tumoral size in OSCCs and that KIF14 might be a potential therapeutic target for development of new treatments for OSCCs.

The role of KIF14 in patient-derived primary cultures of high-grade serous ovarian cancer cells

Objective

Previously, it has been shown that KIF14 mRNA is overexpressed in ovarian cancer (OvCa), regardless of histological subtype. KIF14 levels are independently predictive of poor outcome and increased rates of recurrence in serous OvCa patients. Furthermore, it has been shown that KIF14 also controls the in vivo tumorigenicity of OvCa cell lines. In this study, we evaluate the potential of KIF14 as a therapeutic target through selective inhibition of KIF14 in primary high-grade serous patient-derived OvCa cells.

Methods

To assess the dependence of primary serous OvCa cultures on KIF14, protein levels in 11 prospective high grade serous ovarian cancer samples were increased (KIF14 overexpression by transfection) or decreased (anti-KIF14 shRNA) in vitro, and proliferative capacity, anchorage independence and xenograft growth were assessed.

Results

Seven of eleven samples demonstrated increased/decreased in vitro proliferation in response to KIF14 overexpression/knockdown, respectively. When examining in vitro tumorigenicity (colony formation) and in vivo growth (subcutaneous xenografts) in response to KIF14 manipulation, none of the samples demonstrated growth in soft agar (11 samples), or xenograft growth (4 samples).

Conclusions

Although primary high-grade serous OvCa cells may depend on KIF14 for in vitro proliferation we were unable to demonstrate a role for KIF14 on tumorigenicity or develop an in vivo model for assessment. We have, however developed an effective in vitro method to evaluate the effect of target gene manipulation on the proliferative capacity of primary OvCa cultures.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-014-0123-1) contains supplementary material, which is available to authorized users.

Nuclear envelope invaginations and cancer

The nuclear envelope (NE) surrounds the nucleus and separates it from the cytoplasm. The NE is not a passive structural component, but rather contributes to various cellular processes such as genome organization, transcription, signaling, and stress responses. Although the NE is mostly a smooth surface, it also forms invaginations that can reach deep into the nucleoplasm and may even traverse the nucleus completely. Cancer cells are generally characterized by irregularities and invaginations of the NE that are of diagnostic and prognostic significance. In the current chapter, we describe the link between nuclear invaginations and irregularities with cancer and explore possible mechanistic roles they might have in tumorigenesis.

A distinctive ovarian cancer molecular subgroup characterized by poor prognosis and somatic focal copy number amplifications at chromosome 19

OBJECTIVE

High-grade serous ovarian cancer (HGS-OvCa), the most common epithelial ovarian cancer, is very complex and heterogeneous at the molecular level. The identification of intrinsic HGS-OvCa subgroups characterized by specific molecular alterations and aggressive behavior could improve patient treatment.

METHODS

High-resolution copy number data for 560 HGS-OvCa patients and gene expression data obtained from the TCGA database were analyzed to identify distinct molecular subgroups based on significant focal somatic copy number alterations (SCNAs).

RESULTS

Using unsupervised consensus clustering, a subgroup accounting for 26.8% of the patients (150/560 patients) characterized by focal somatic copy number amplification at chromosome 19 was identified. The subgroup was independently associated by multivariate Cox regression analysis with poor overall (HR, 1.61; P = 0.001) and progression-free survival (HR, 1.36; P = 0.036). The specific focal SCNA locations were 19p13.2, 19p13.12, 19p13.11, 19q12, 19q13.12, and 19q13.2. The differential gene expression signature of the subgroup compared with that of the remaining patients also suggested that chromosome 19 was the mainly amplified region. The clinical significances of subgroup 2 were validated in independent data sets using the gene expression signature characteristics. In addition, the subgroup had a tendency toward mutual exclusivity with patients with BRCA1/2 mutations. The most significantly altered pathway of the subgroup was the cyclin and cell cycle regulation pathway.

CONCLUSION

A unique molecular subgroup associated with poor survival was identified based on focal SCNAs and could aid the further molecular classification of ovarian cancers.

Losses of chromosome 5q and 14q are associated with favorable clinical outcome of patients with gastric cancer

PURPOSE

To improve the clinical outcome of patients with gastric cancer, intensified combination strategies are currently in clinical development, including combinations of more extensive surgery, (neo)adjuvant chemotherapy, and radiotherapy. The present study used DNA copy number profiling to identify subgroups of patients with different clinical outcomes. We hypothesize that, by identification of subgroups, individual treatment strategies can be selected to improve clinical outcome and to reduce unnecessary treatment toxicity for patients with gastric cancer.

EXPERIMENTAL DESIGN

DNA from 206 gastric cancer patients was isolated and analyzed by genomewide array comparative genomic hybridization. DNA copy number profiles were correlated with lymph node status and patient survival. In addition, heat shock protein 90 (HSP90) expression was analyzed and correlated with survival in 230 gastric cancer patients.

RESULTS

Frequent (>20%) DNA copy number gains and losses were observed on several chromosomal regions. Losses on 5q11.2-q31.3 and 14q32.11-q32.33 (14% of patients) were correlated with good clinical outcome in univariate and multivariate analyses, with a median disease-free survival interval of 9.2 years. In addition, loss of expression of HSP90, located on chromosome 14q32.2, was correlated with better patient survival.

CONCLUSION

Genomewide DNA copy number profiling allowed the identification of a subgroup of gastric cancer patients, marked by losses on chromosomes 5q11.2-q31.3 and 14q32.11-q32.33 or low HSP90 protein expression, with an excellent clinical outcome after surgery alone. We hypothesize that this subgroup of patients most likely will not benefit from (neo)adjuvant systemic treatment and/or radiotherapy, whereas anti-HSP90 therapy may have clinical potential in patients with HSP90-expressing gastric cancer, pending validation in an independent dataset.

Molecular requirements for transformation of fallopian tube epithelial cells into serous carcinoma

Although controversial, recent studies suggest that serous ovarian carcinomas may arise from fallopian tube fimbria rather than ovarian surface epithelium. We developed an in vitro model for serous carcinogenesis in which primary human fallopian tube epithelial cells (FTECs) were exposed to potentially oncogenic molecular alterations delivered by retroviral vectors. To more closely mirror in vivo conditions, transformation of FTECs was driven by the positive selection of growth-promoting alterations rather antibiotic selection. Injection of the transformed FTEC lines in SCID mice resulted in xenografts with histologic and immunohistochemical features indistinguishable from poorly differentiated serous carcinomas. Transcriptional profiling revealed high similarity among the transformed and control FTEC lines and patient-derived serous ovarian carcinoma cells and was used to define a malignancy-related transcriptional signature. Oncogene-treated FTEC lines were serially analyzed using quantitative reverse transcription-polymerase chain reaction and immunoblot analysis to identify oncogenes whose expression was subject to positive selection. The combination of p53 and Rb inactivation (mediated by SV40 T antigen), hTERT expression, and oncogenic C-MYC and HRAS accumulation showed positive selection during transformation. Knockdown of each of these selected components resulted in significant growth inhibition of the transformed cell lines that correlated with p27 accumulation. The combination of SV40 T antigen and hTERT expression resulted in immortalized cells that were nontumorigenic in mice, whereas forced expression of a dominant-negative p53 isoform (p53DD) and hTERT resulted in senescence. Thus, our investigation supports the tubal origin of serous carcinoma and provides a dynamic model for studying early molecular alterations in serous carcinogenesis.

Chromosomal regions associated with prostate cancer risk localize to lamin B-deficient microdomains and exhibit reduced gene transcription

The lamins are major determinants of nuclear shape and chromatin organization and these features are frequently altered in prostate cancer (CaP). Human CaP cell lines frequently have nuclear lobulations, which are enriched in A-type lamins but lack B-type lamins and have been defined as lamin B-deficient microdomains (LDMDs). LDMD frequency is correlated with CaP cell line aggressiveness and increased cell motility. In addition, LNCaP cells grown in the presence of dihydrotestosterone (DHT) show an increased frequency of LDMDs. The LDMDs are enriched in activated RNA polymerase II (Pol IIo) and androgen receptor (AR) and A-type lamins form an enlarged meshwork that appears to co-align with chromatin fibres and AR. Furthermore, fluorescence in situ hybridization and comparative genomic hybridization demonstrated that chromosomal regions associated with CaP susceptibility are preferentially localized to LDMDs. Surprisingly, these regions lack histone marks for transcript elongation and exhibit reduced BrU incorporation, suggesting that Pol II is stalled within LDMDs. Real-time PCR of genes near androgen response elements (AREs) was used to compare transcription between cells containing LDMDs and controls. Genes preferentially localized to LDMDs showed significantly decreased expression, while genes in the main nuclear body were largely unaffected. Furthermore, LDMDs were observed in human CaP tissue and the frequency was correlated with increased Gleason grade. These results imply that lamins are involved in chromatin organization and Pol II transcription, and provide insights into the development and progression of CaP.

Kinesin family member 14: an independent prognostic marker and potential therapeutic target for ovarian cancer

The novel oncogene KIF14 (kinesin family member 14) shows genomic gain and overexpression in many cancers including OvCa (ovarian cancer). We discovered that expression of the mitotic kinesin KIF14 is predictive of poor outcome in breast and lung cancers. We now determine the prognostic significance of KIF14 expression in primary OvCa tumors, and evaluate KIF14 action on OvCa cell tumorigenicity in vitro. Gene-specific multiplex PCR and real-time QPCR were used to measure KIF14 genomic (109 samples) and mRNA levels (122 samples) in OvCa tumors. Association of KIF14 with clinical variables was studied using Kaplan-Meier survival and Cox regression analyses. Cellular effects of KIF14 overexpression (stable transfection) and inhibition (stable shRNA knockdown) were studied by proliferation (cell counts), survival (Annexin V immunocytochemistry) and colony formation (soft-agar growth). KIF14 genomic gain (>2.6 copies) was present in 30% of serous OvCas, and KIF14 mRNA was elevated in 91% of tumors versus normal epithelium. High KIF14 in tumors independently predicted for worse outcome (p = 0.03) with loss of correlation with proliferation marker expression and increased rates of recurrence. Overexpression of KIF14 in OvCa cell lines increased proliferation and colony formation (p < 0.01), whereas KIF14 knockdown induced apoptosis and dramatically reduced colony formation (p < 0.05). Our findings indicate that KIF14 mRNA is an independent prognostic marker in serous OvCa. Dependence of OvCa cells on KIF14 for maintenance of in vitro colony formation suggests a role of KIF14 in promoting a tumorigenic phenotype, beyond its known role in proliferation.

Molecular Pathology of Ovarian Carcinomas

This content presents a review of molecular pathology of ovarian cancer. The authors present key molecular features for high-grade and low-grade serous carcinomas, endometrioid carcinomas, clear cell carcinomas, and mucinous carcinomas. Cell lineage, mutation and gene expression, pathway alterations, risk factors, prognostic markers, and treatment targets are discussed.

Gene expression: protein interaction systems network modeling identifies transformation-associated molecules and pathways in ovarian cancer

Multiple, dissimilar genetic defects in cancers of the same origin contribute to heterogeneity in tumor phenotypes and therapeutic responses of patients, yet the associated molecular mechanisms remain elusive. Here, we show at the systems level that serous ovarian carcinoma is marked by the activation of interconnected modules associated with a specific gene set that was derived from three independent tumor-specific gene expression data sets. Network prediction algorithms combined with preestablished protein interaction networks and known functionalities affirmed the importance of genes associated with ovarian cancer as predictive biomarkers, besides "discovering" novel ones purely on the basis of interconnectivity, whose precise involvement remains to be investigated. Copy number alterations and aberrant epigenetic regulation were identified and validated as significant influences on gene expression. More importantly, three functional modules centering on c-Myc activation, altered retinoblastoma signaling, and p53/cell cycle/DNA damage repair pathways have been identified for their involvement in transformation-associated events. Further studies will assign significance to and aid the design of a panel of specific markers predictive of individual- and tumor-specific pathways. In the parlance of this emerging field, such networks of gene-hub interactions may define personalized therapeutic decisions.

Gene expression meta-analysis identifies chromosomal regions involved in ovarian cancer survival

Ovarian cancer cells exhibit complex karyotypic alterations causing deregulation of numerous genes. Some of these genes are probably causal for cancer formation and local growth, whereas others are causal for metastasis and recurrence. By using publicly available data sets, we have investigated the relation of gene expression and chromosomal position to identify chromosomal regions of importance for early recurrence of ovarian cancer. By use of *Gene Set Enrichment Analysis*, we have ranked chromosomal regions according to their association to survival. Over-representation analysis including 1-4 consecutive cytogenetic bands identified regions with increased expression for chromosome 5q12-14, and a very large region of chromosome 7 with the strongest signal at 7p15-13 among tumors from short-living patients. Reduced gene expression was identified at 4q26-32, 6p12-q15, 9p21-q32, and 11p14-11. We summarized mutation load in these regions by a combined mutation score that is statistical significantly associated to survival by analysis in the data sets used for identification of the regions. Furthermore, the prognostic value of the combined mutation score was validated in an independent large data set using death (P = 0.015) and recurrence (P = 0.002) as outcome. The combined mutation score is strongly associated to upregulation of several growth factor pathways.

Integrated genome-wide DNA copy number and expression analysis identifies distinct mechanisms of primary chemoresistance in ovarian carcinomas

PURPOSE

A significant number of women with serous ovarian cancer are intrinsically refractory to platinum-based treatment. We analyzed somatic DNA copy number variation and gene expression data to identify key mechanisms associated with primary resistance in advanced-stage serous cancers.

EXPERIMENTAL DESIGN

Genome-wide copy number variation was measured in 118 ovarian tumors using high-resolution oligonucleotide microarrays. A well-defined subset of 85 advanced-stage serous tumors was then used to relate copy number variation to primary resistance to treatment. The discovery-based approach was complemented by quantitative-PCR copy number analysis of 12 candidate genes as independent validation of previously reported associations with clinical outcome. Likely copy number variation targets and tumor molecular subtypes were further characterized by gene expression profiling.

RESULTS

Amplification of 19q12, containing cyclin E (CCNE1), and 20q11.22-q13.12, mapping immediately adjacent to the steroid receptor coactivator NCOA3, was significantly associated with poor response to primary treatment. Other genes previously associated with copy number variation and clinical outcome in ovarian cancer were not associated with primary treatment resistance. Chemoresistant tumors with high CCNE1 copy number and protein expression were associated with increased cellular proliferation but so too was a subset of treatment-responsive patients, suggesting a cell-cycle independent role for CCNE1 in modulating chemoresponse. Patients with a poor clinical outcome without CCNE1 amplification overexpressed genes involved in extracellular matrix deposition.

CONCLUSIONS

We have identified two distinct mechanisms of primary treatment failure in serous ovarian cancer, involving CCNE1 amplification and enhanced extracellular matrix deposition. CCNE1 copy number is validated as a dominant marker of patient outcome in ovarian cancer.

Integrated genome-wide DNA copy number and expression analysis identifies distinct mechanisms of primary chemoresistance in ovarian carcinomas

PURPOSE

A significant number of women with serous ovarian cancer are intrinsically refractory to platinum-based treatment. We analyzed somatic DNA copy number variation and gene expression data to identify key mechanisms associated with primary resistance in advanced-stage serous cancers.

EXPERIMENTAL DESIGN

Genome-wide copy number variation was measured in 118 ovarian tumors using high-resolution oligonucleotide microarrays. A well-defined subset of 85 advanced-stage serous tumors was then used to relate copy number variation to primary resistance to treatment. The discovery-based approach was complemented by quantitative-PCR copy number analysis of 12 candidate genes as independent validation of previously reported associations with clinical outcome. Likely copy number variation targets and tumor molecular subtypes were further characterized by gene expression profiling.

RESULTS

Amplification of 19q12, containing cyclin E (CCNE1), and 20q11.22-q13.12, mapping immediately adjacent to the steroid receptor coactivator NCOA3, was significantly associated with poor response to primary treatment. Other genes previously associated with copy number variation and clinical outcome in ovarian cancer were not associated with primary treatment resistance. Chemoresistant tumors with high CCNE1 copy number and protein expression were associated with increased cellular proliferation but so too was a subset of treatment-responsive patients, suggesting a cell-cycle independent role for CCNE1 in modulating chemoresponse. Patients with a poor clinical outcome without CCNE1 amplification overexpressed genes involved in extracellular matrix deposition.

CONCLUSIONS

We have identified two distinct mechanisms of primary treatment failure in serous ovarian cancer, involving CCNE1 amplification and enhanced extracellular matrix deposition. CCNE1 copy number is validated as a dominant marker of patient outcome in ovarian cancer.

Critical molecular abnormalities in high-grade serous carcinoma of the ovary

Ovarian carcinomas show more morphological heterogeneity than adenocarcinomas of any other body site. It has recently become clear that the morphologically defined subtypes of ovarian carcinoma are distinct diseases, with different risk factors, molecular events during oncogenesis, likelihood of spread, responses to chemotherapy, and outcomes. This review focuses on molecular abnormalities (in genes expressing BRCA1/2, TP53 and RB1/CCND1/CDKN2A/E2F) found in high-grade serous carcinomas of the ovary, which account for most ovarian cancer deaths. These highly aggressive but chemosensitive tumours are associated with perturbation of molecular pathways leading to genomic instability and extreme mutability and present unique challenges in oncological research and practice.

Molekularpathologie der epithelialen Ovarialneoplasien

Despite the fact that ovarian carcinomas are phenotypically heterogeneous, they can be divided into two main groups with common pathogenetic mechanisms. Based on clinical, pathological and molecular parameters, a relatively large group of tumors can be distinguished with stepwise development from benign precursors and borderline tumors to invasive carcinomas (type I). Depending on the morphological phenotype, characteristic genetic changes can be observed, such as mutations in KRAS and BRAF in serous borderline tumors and low-grade serous carcinomas. Mutations in KRAS are also frequently detected in mucinous borderline tumors and mucinous carcinomas. The group of endometrioid tumors is characterized by mutations in components of the Wnt-signal transduction pathway and PTEN or microsatellite instability. The second large group of tumors (type II) includes tumors with "de novo" development of highly malignant carcinomas such as the conventional (moderately to poorly differentiated) high-grade serous carcinomas, undifferentiated carcinomas and malignant mixed mesodermal tumors. These tumors are associated with frequent mutations in p53 and complex chromosomal alterations. In the future, the combined analysis of morphological parameters, genetic changes, gene-expression profiling and protein data will reveal possible diagnostic and therapeutic targets for ovarian carcinomas.

High-level amplification at 17q23 leads to coordinated overexpression of multiple adjacent genes in breast cancer

Increased copy numbers of 17q23 chromosomal region have been shown to occur in different tumour types and to be associated with tumour progression and with poor prognosis. Several genes have earlier been proposed as potential oncogenes at this region largely on the grounds of cell lines studies. In this study, we performed a systematic gene expression survey on 26 primary breast tumours with known 17q23 amplification status by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The 17q23 amplicon is restricted to an approximately 5 MB region in breast cancer and contains 29 known genes. Our survey revealed a statistically significant (P<0.01) difference between the high level and no amplification groups in a set of eleven genes whereas no difference between the moderate and the non-amplified tumour groups were observed. Interestingly, these 11 genes were located adjacent to one another within a 1.56 Mb core region in which all except one of the genes were overexpressed. These data suggest that only high-level amplification at the 17q23 amplicon core leads to elevated gene expression in breast cancer. Moreover, our results highlight the fact that 17q23 amplicon carries multiple candidate genes and that this may be a more common event in gene amplification than previously thought.

UK external quality assessment scheme for immunoassays in endocrinology

UK EQAS provide the UK with a comprehensive system for EQA in endocrinology, as well as in other aspects of clinical chemistry and laboratory medicine. UK EQAS in endocrinology are scientifically designed to yield an objective assessment of participants' performance and stimulate improvements in between-laboratory agreement. The design uses appropriate specimens, based on liquid human serum and prepared with minimal processing and additives in the organising centres to enable detailed study of recovery and other important factors. Target values are validated by reproducibility on repeated distribution and by recovery and parallelism studies. Reports are presented informatively, and emphasise the cumulative scoring system (bias and variance) for performance assessment. Computerised data processing and data presentation form an integral part of these schemes, and a common core computing system is in use throughout these UK EQAS. Participants receive advice and assistance in the interpretation of performance data and, when appropriate, in the resolution of problems.