Human epididymis protein 4 (HE4) is a secreted glycoprotein that is overexpressed by serous and endometrioid ovarian carcinomas

Status of tumor markers in epithelial ovarian cancer has there been any progress? A review

OBJECTIVE

The aim is to present an overview of tumor markers other than CA-125 that have been proposed for use in the diagnosis of epithelial ovarian cancer and explore molecular studies which have been used to identify genomic and proteomic changes associated with this malignancy for possible future development of more sensitive tumor markers.

METHODS

A Medline search was conducted to review published articles from American and European studies from 1990 to 2010, related to tumor markers for ovarian cancer. Different methods such as genomic, proteomic and transcriptional profiling were used to identify new tumor markers for clinical use.

RESULTS

A few of the newer tumor markers alone have demonstrated equal or slightly higher sensitivity to CA-125. Improved sensitivity and specificity have been reported using these new markers combined with CA-125.

CONCLUSION

Addition of new tumor markers as a compliment to CA-125 were associated with higher sensitivity and detection rates than either marker alone. However, the low prevalence of ovarian cancer necessitates a higher level of sensitivity and specificity that has still not been achieved if these biomarkers are used for diagnosis and monitoring the disease progress as a result of low positive predictive value.

Peri- and post-menopausal incidental adnexal masses and the risk of sporadic ovarian malignancy: new insights and clinical management

Adnexal masses are common among peri- and post-menopausal women. Although ovarian cancer is a significant cause of mortality in menopausal women, large population-based studies demonstrate that the majority of adnexal masses are benign. Despite this, the appearance of an adnexal mass is a concern for the patient and an insight exercise for physicians. In most cases, an adnexal enlargement is an incidental finding, generally corresponding to a benign cyst and easily diagnosed by conventional ultrasound. Exceptionally an ovarian tumour may be malignant and should be treated as early as possible. When conventional ultrasound renders complex morphology other diagnostic tools must be used such as: colour Doppler and functional tumour vessel properties, serum CA 125 levels, nuclear magnetic resonance imaging and in some cases laparoscopy. Several new tumour markers are being studied for clinical application, although there are presently no clear recommendations. Adnexal masses with benign morphological and functional properties must be periodically monitored as an alternative to surgery since malignant transformation is exceptional.

Proteomics and the search for biomarkers of female reproductive diseases

Over the past decade, high-throughput proteomics technologies have evolved considerably and have become increasingly more commonly applied to the investigation of female reproductive diseases. Proteomic approaches facilitate the identification of new disease biomarkers by comparing the abundance of hundreds of proteins simultaneously to find those specific to a particular clinical condition. Some of the best studied areas of female reproductive biology applying proteomics include gynaecological cancers, endometriosis and endometrial infertility. This review will discuss the progress that has been made in these areas and will highlight some of the emerging technologies that promise to contribute to better understanding of the female reproductive disease.

PAX8 reliably distinguishes ovarian serous tumors from malignant mesothelioma

Ovarian serous neoplasms can have morphologic overlap with malignant mesothelioma. The distinction is clinically important, yet most studies have failed to identify immunostains that reliably distinguish these 2 tumor types. Recently, transcription factor PAX8 was shown to be a sensitive and relatively specific marker for Müllerian tumors. In addition, some studies suggest that h-caldesmon is sensitive and specific for mesothelioma when compared with serous ovarian tumors. The goal of this study was to evaluate whether PAX8 and h-caldesmon expression can successfully distinguish mesothelioma from serous ovarian tumors. Immunohistochemistry was carried out using PAX8 and h-caldesmon antibodies on archival tissue from 254 ovarian serous tumors and 50 mesothelial tumors. Nuclear and cytoplasmic immunoreactivity were considered positive for PAX8 and h-caldesmon, respectively. PAX8 staining was present in 99% of high-grade serous ovarian carcinomas and all (100%) low-grade ovarian carcinomas and serous borderline tumors; however, only 74% of these cases (188/254) were diffusely positive in more than 50% of tumors cells, and intensity ranged from strong to weak. None of the pleural malignant mesotheliomas were reactive with PAX8. However, 2/23 (9%) peritoneal malignant mesotheliomas showed focal and/or weak staining for PAX8; the remaining cases were negative. Two well-differentiated papillary mesotheliomas and 1 multicystic mesothelioma each showed some staining for PAX8. h-caldesmon was negative in all serous neoplasms and all mesothelial neoplasms, except 1 pleural malignant mesothelioma which showed patchy immunoreactivity. Strong PAX8 staining is highly specific (P<0.00001) for ovarian serous tumors when compared with malignant mesotheliomas of the peritoneum and pleura. The presence of weak staining for PAX8 in the 3 "noninvasive" mesotheliomas questions the use for PAX8 in this differential diagnosis. On the basis of this study, h-caldesmon is not a useful marker for mesothelioma.

Overexpression of elafin in ovarian carcinoma is driven by genomic gains and activation of the nuclear factor kappaB pathway and is associated with poor overall survival

Ovarian cancer is a leading cause of cancer mortality in women. The aim of this study was to elucidate whether whey acidic protein (WAP) genes on chromosome 20q13.12, a region frequently amplified in this cancer, are expressed in serous carcinoma, the most common form of the disease. Herein, we report that a trio of WAP genes (HE4, SLPI, and Elafin) is overexpressed and secreted by serous ovarian carcinomas. To our knowledge, this is the first report linking Elafin to ovarian cancer. Fluorescence in situ hybridization analysis of primary tumors demonstrates genomic gains of the Elafin locus in a majority of cases. In addition, a combination of peptidomimetics, RNA interference, and chromatin immunoprecipitation experiments shows that Elafin expression can be transcriptionally upregulated by inflammatory cytokines through activation of the nuclear factor kappaB pathway. Importantly, using a clinically annotated tissue microarray composed of late-stage, high-grade serous ovarian carcinomas, we show that Elafin expression correlates with poor overall survival. These results, combined with our observation that Elafin is secreted by ovarian tumors and is minimally expressed in normal tissues, suggest that Elafin may serve as a determinant of poor survival in this disease.

Human epididymis protein 4 is a biomarker for transitional cell carcinoma in the urinary system

OBJECTIVE

To investigate human epididymis protein 4 (HE4) levels in transitional cell carcinoma (TCC) of the urinary system and its relationship with clinicopathological features.

METHODS

102 patients with TCC, 60 with benign urinary diseases, and 60 healthy controls were included in this study. The HE4 levels were used to analyze different clinicopathologic characteristics and changes between pre- and postsurgical operation.

RESULTS

The HE4 level was significantly increased in patients with TCC compared to patients with benign urinary diseases patients (P<0.01) and healthy controls (P<0.01), and the level of HE4 in patients with superficial TCC (Tis Ta T1) was significantly higher than that of the benign urogenital group (P<0.05)and healthy controls (P<0.05). There was a significant difference between HE4 levels in patients before and after operation (P<0.05). There was no difference between HE4 levels based on tumor recurrence, clinical TNM stage, lymph node metastasis, or pathological stage (P>0.05). The HE4 level was also different between patients with a single tumor versus patients with multiple tumors. The area under the curves of HE4 is 0.821. The sensitivity and specificity of HE4 at a cutoff value of 45.7 pM were 67.6 and 88.3%, respectively.

CONCLUSIONS

HE4 may be a screening tool for early diagnosis of TCC in the urinary system, and may become a prognostic marker for TCC in the urinary system.

Use of a Symptom Index, CA125, and HE4 to predict ovarian cancer

BACKGROUND

Prior studies suggest that combining the Symptom Index (SI) with a serum HE4 test or a CA125 test may improve prediction of ovarian cancer. However, these three tests have not been evaluated in combination.

METHODS

A prospective case-control study design including 74 women with ovarian cancer and 137 healthy women was used with logistic regression analysis to evaluate the independent contributions of HE4 and CA125, and the SI to predict ovarian cancer status in a multivariate model. The diagnostic performance of various decision rules for combinations of these tests was assessed to evaluate potential use in predicting ovarian cancer.

RESULTS

The SI, HE4, and CA125 all made significant independent contributions to ovarian cancer prediction. A decision rule based on any one of the three tests being positive had a sensitivity of 95% with specificity of 80%. A rule based on any two of the three tests being positive had a sensitivity of 84% with a specificity of 98.5%. The SI alone had sensitivity of 64% with specificity of 88%. If the SI index is used to select women for CA125 and HE4 testing, specificity is 98.5% and sensitivity is 58% using the 2-of-3-positive decision rule.

CONCLUSIONS

A 2-of-3-positive decision rule yields acceptable specificity, and higher sensitivity when all 3 tests are performed than when the SI is used to select women for screening by CA125 and HE4. If positive predictive value is a high priority, testing by CA125 and HE4 prior to imaging may be warranted for women with ovarian cancer symptoms.

The utility of serum human epididymis protein 4 (HE4) in patients with a pelvic mass

AIM

Although CA125 is the most widely used cancer marker in the diagnostic approach of pelvic masses in women, its clinical usefulness is limited because it lacks expression of the antigen in the early stages of disease. The human epididymis protein 4 (HE4) is frequently over-expressed in ovarian cancer, whereas its expression in normal tissues, including the ovary, is low. The aim of this study was to assess the concentration of both HE4 and CA125 in patients with different forms of benign and malign pelvic masses.

METHODS

The study population included 99 patients with gynecological cancer (46 ovarian, 39 endometrial, 14 cervical) and 40 affected by benign disease (22 endometriosis and 18 benign ovarian mass). Twelve control subjects were also included in the study. In all the patients, serum samples were collected on the day before scheduled surgery.

RESULTS

The median CA125 and HE4 serum levels were significantly higher among ovarian cancer patients as compared with healthy subjects and with those with benign mass, cervical, and endometrial tumors. The receiver operating characteristics curve analysis on healthy controls and patients with ovarian cancers revealed that HE4 had a significantly higher area under the curve when compared with CA125 (0.99 vs. 0.91), with a sensibility and specificity of 98 and 100%, respectively.

CONCLUSIONS

HE4 seems to be a promising ovarian cancer marker, and its measurement might improve the diagnostic approach to patients with pelvic masses.

HE4: a new potential early biomarker for the recurrence of ovarian cancer

Human epididymis protein 4 (HE4) has recently been described as a new marker for the early diagnosis of ovarian cancer (OC). The objective of this study was to evaluate (a) the expression of HE4 vs. OC mucin CA125 in 32 patients with OC compared to 163 patients with other malignant or benign pathologies (b) HE4 as indicator of the recurrence of the disease in eight patients followed-up for 20 months after OC diagnosis. Serum HE4 and CA 125 levels were determined by ELISA and IRMA, respectively. At diagnosis, the patients with OC demonstrated high levels of both biomarkers with 96.9% sensitivity for HE4 and 85.7% for CA125. In the other pathologies there was 3.7% positivity for HE4 and 21.0% for CA125. The follow-up study showed an increase of HE4 5-8 months before CA125 increment in five of the eight patients, this early expression being strictly associated to a relapse of the disease. In conclusion, this study showed that HE4, compared to CA125, potentially is a better marker for the diagnosis of OC and could be an important early indicator of the recurrence of the disease.

Assessing lead time of selected ovarian cancer biomarkers: a nested case-control study

Background

CA125, human epididymis protein 4 (HE4), mesothelin, B7-H4, decoy receptor 3 (DcR3), and spondin-2 have been identified as potential ovarian cancer biomarkers. Except for CA125, their behavior in the prediagnostic period has not been evaluated.

Methods

Immunoassays were used to determine concentrations of CA125, HE4, mesothelin, B7-H4, DcR3, and spondin-2 proteins in prediagnostic serum specimens (1–11 samples per participant) that were contributed 0–18 years before ovarian cancer diagnosis from 34 patients with ovarian cancer (15 with advanced-stage serous carcinoma) and during a comparable time interval before the reference date from 70 matched control subjects who were participating in the Carotene and Retinol Efficacy Trial. Lowess curves were fit to biomarker levels in cancer patients and control subjects separately to summarize mean levels over time. Receiver operating characteristic curves were plotted, and area-under-the curve (AUC) statistics were computed to summarize the discrimination ability of these biomarkers by time before diagnosis.

Results

Smoothed mean concentrations of CA125, HE4, and mesothelin (but not of B7-H4, DcR3, and spondin-2) began to increase (visually) in cancer patients relative to control subjects approximately 3 years before diagnosis but reached detectable elevations only within the final year before diagnosis. In descriptive receiver operating characteristic analyses, the discriminatory power of these biomarkers was limited (AUC statistics range = 0.56–0.75) but showed increasing accuracy with time approaching diagnosis (eg, AUC statistics for CA125 were 0.57, 0.68, and 0.74 for ≥4, 2–4, and <2 years before diagnosis, respectively).

Conclusion

Serum concentrations of CA125, HE4, and mesothelin may provide evidence of ovarian cancer 3 years before clinical diagnosis, but the likely lead time associated with these markers appears to be less than 1 year.

HE4 as a biomarker for ovarian and endometrial cancer management

Ovarian and endometrial cancer will be diagnosed in over 63,000 women in 2009, resulting in 22,000 deaths in the USA. Histologic screening, such as pap smears for detection of cervical cancer, is not feasible for these diseases given difficulty with access to the tissue. Thus, a serum- screening test using a biomarker or panel of biomarkers would be useful to aid in cancer diagnosis, detection of recurrence and as a means to monitor response to therapy. In this review, we focus on the human epididymis protein (HE)4 gene, which appears to have potential as a biomarker for both of these diseases. The structure and methods of detection of HE4 are discussed. Preliminary data show that HE4 may have more potential than cancer antigen 125 in discriminating benign from cancerous ovarian masses, and has the strongest correlation with endometrial cancer of all markers tested to date. Utilizing risk stratification, a panel of biomarkers including HE4 may ultimately be useful for detecting ovarian and endometrial cancer at an early stage in patients at high risk.

Primary ex vivo cultures of human fallopian tube epithelium as a model for serous ovarian carcinogenesis

Recent studies suggest that some serous ovarian carcinomas (SOCs) arise from the fallopian tube (FT) epithelium rather than the ovarian surface epithelium. This hypothesis places emphasis on the FT secretory epithelial cell as a cell-of-origin. Herein, we report the development of a novel ex vivo primary human FT epithelium culture system that faithfully recapitulates the in vivo epithelium, as shown by morphological, ultrastructural and immunophenotypic analyses. Mass spectrometry-based proteomics reveal that these cultures secrete proteins previously identified as biomarkers for ovarian cancer. We also use this culture system to study the response of the FT epithelium to genotoxic stress and find that the secretory cells exhibit a distinct response to DNA damage when compared with neighboring ciliated cells. The secretory cells show a limited ability to resolve the damage over time, potentially leaving them more susceptible to accumulation of additional mutagenic injury. This divergent response is confirmed with in situ studies using tissue samples, further supporting the use of this ex vivo culture system to investigate FT epithelial pathobiology. We anticipate that this novel culture system will facilitate the study of SOC pathogenesis, and propose that similar culture systems could be developed for other organ site-specific epithelia.

Protein profiling of pleural effusions to identify malignant pleural mesothelioma using SELDI-TOF MS

Diagnosis of malignant pleural mesothelioma (MM) is limited. Novel proteomic techno_logies can be utilized to discover changes in expression of pleural proteins that might have diagnostic value. The objective of this study was to detect protein profiles that could be used to identify malignant pleural mesothelioma with surface enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS). Pleural effusions were collected from patients with confirmed mesothelioma (n = 41) and from patients with effusions due to other causes ([n = 48] cancerous and non-cancerous). Samples were fractionated using anion exchange chromatography and bound to different types of ProteinChip array surfaces. All samples were also subjected to other commercially available immunoassays (human epididymes protein 4 [HE4], osteopontin [OPN], soluble mesothelin-related proteins [SMRP], and the cytokeratin 19 fragment [CYFRA 21-1]). Peak intensity data obtained by SELDI-TOF were subjected to classification algorithms in order to identify potential classifier peaks. A protein peak at m/z 6614 was characterized as apolipoprotein (Apo) CI. In this setting, the sensitivity and specificity of this potential biomarker was 76 % and 69 %, respectively. The area under the receiver operating characteristic curve (AUC) for Apo CI was 0.755, thereby outperforming OPN, HE4, and CYFRA 21-1. SMRP performed best with an AUC of 0.860 with a sensitivity of 83% and specificity of 74%. Our study validates the use of SMRP as a diagnostic marker for pleural mesothelioma and furthermore suggests that Apo CI levels could be used in the future to discriminate pleural mesothelioma from other causes of exudates.

Current state of biomarker development for clinical application in epithelial ovarian cancer

Each year in the United States over 15,000 women die of epithelial ovarian cancer (EOC) and 22,000 are diagnosed with the disease. The incidence of ovarian cancer has remained stable over the past decade however, survival rates have improved steadily. Increases in survival rates can be attributed to the advances in surgical management, development of effective cytotoxic drugs and the route of administration of chemotherapy. Ovarian cancer survival rates could also be improved through screening and early detection. Disappointingly, effective screening methods have not been established and continue to be elusive. Historically the goal of a screening test was to achieve a positive predictive value (PPV) greater than 10% in order be considered cost effective and have an acceptable risk for the population being screened. Despite the inability of currently available screening algorithms to achieve the desired PPV there may be an advantage in producing a stage migration to lower stages at the time of diagnoses, thereby resulting in improved survival. Equally important recent studies have demonstrated that women who have their initial surgery performed by gynecologic oncologists, and women who have their surgeries at centers experienced in the treatment of ovarian cancer have higher survival rates. For these reasons it is essential that all women at high risk for ovarian cancer receive their initial care by gynecologic oncologists and at centers with multidisciplinary teams experienced in the optimal care of ovarian cancer patients. With this in mind, methods that facilitate the accurate triage of women who will ultimately be diagnosed with ovarian cancer could play a significant role in improving survival rates for these patients. This review article will examine the current state of biomarker use in ovarian cancer screening, risk assessment and for monitoring ovarian cancer patients.

Expression profiling identifies genes involved in neoplastic transformation of serous ovarian cancer

Background

The malignant potential of serous ovarian tumors, the most common ovarian tumor subtype, varies from benign to low malignant potential (LMP) tumors to frankly invasive cancers. Given the uncertainty about the relationship between these different forms, we compared their patterns of gene expression.

Methods

Expression profiling was carried out on samples of 7 benign, 7 LMP and 28 invasive (moderate and poorly differentiated) serous tumors and four whole normal ovaries using oligonucleotide microarrays representing over 21,000 genes.

Results

We identified 311 transcripts that distinguished invasive from benign tumors, and 20 transcripts that were significantly differentially expressed between invasive and LMP tumors at p < 0.01 (with multiple testing correction). Five genes that were differentially expressed between invasive and either benign or normal tissues were validated by real time PCR in an independent panel of 46 serous tumors (4 benign, 7 LMP, 35 invasive). Overexpression of SLPI and WNT7A and down-regulation of C6orf31, PDGFRA and GLTSCR2 were measured in invasive and LMP compared with benign and normal tissues. Over-expression of WNT7A in an ovarian cancer cell line led to increased migration and invasive capacity.

Conclusion

These results highlight several genes that may play an important role across the spectrum of serous ovarian tumorigenesis.

Ovarian cancer pathogenesis: a model in evolution

Ovarian cancer is a deadly disease for which there is no effective means of early detection. Ovarian carcinomas comprise a diverse group of neoplasms, exhibiting a wide range of morphological characteristics, clinical manifestations, genetic alterations, and tumor behaviors. This high degree of heterogeneity presents a major clinical challenge in both diagnosing and treating ovarian cancer. Furthermore, the early events leading to ovarian carcinoma development are poorly understood, thus complicating efforts to develop screening modalities for this disease. Here, we provide an overview of the current models of ovarian cancer pathogenesis, highlighting recent findings implicating the fallopian tube fimbria as a possible site of origin of ovarian carcinomas. The ovarian cancer model will continue to evolve as we learn more about the genetics and etiology of this disease.

Influence of ovarian cancer risk status on the diagnostic performance of the serum biomarkers mesothelin, HE4, and CA125

OBJECTIVE

To evaluate the effect of ovarian cancer risk on the performance of the serum biomarkers mesothelin, human epididymis protein 4 (HE4), and CA125.

METHODS

We measured mesothelin, HE4, and CA125 levels from women with invasive ovarian cancer (n = 143), benign gynecologic conditions (n = 124), and controls (n = 344). Demographic, epidemiologic, reproductive, medical, and family history data were collected using a standardized questionnaire. Pedigree and BRCA 1/2 test results were used to stratify women into average and high-risk groups. The diagnostic accuracy of each biomarker was characterized using receiver operating characteristic curve methods.

RESULTS

Baseline characteristics did not vary by risk or case status. The distribution of stage and histology was similar in average and high-risk women. All three markers discriminated ovarian cancer cases from risk-matched healthy and benign controls. Marker performance did not vary by risk status. The sensitivity at 95% specificity for discriminating cases from risk-matched healthy control women in the average and high-risk groups, respectively, was 53.9% and 39.0% for mesothelin, 80.4% and 87.8% for HE4, and 79.4% and 82.9% for CA125. The performance of the markers was not as robust when cases were compared with benign controls. Area under the curve values for cases versus healthy and benign controls did not vary by risk status.

CONCLUSIONS

The ability of serum mesothelin, HE4, and CA 125 levels to discriminate ovarian cancer cases from healthy and benign controls is not influenced by risk status. Our findings support the pursuit of additional studies evaluating the early detection potential of these markers in high-risk populations.

Serum HE4 concentration differentiates malignant ovarian tumours from ovarian endometriotic cysts

Human epididymal secretory protein E4 (HE4, also known as WAP four-disulphide core domain protein 2) is a new promising biomarker for ovarian cancer but its specificity against ovarian endometriotic cysts is only superficially known. We, thus, analysed serum HE4 concentrations together with a tumour marker CA125 in serum samples of women diagnosed with various types of endometriosis, endometrial cancer or ovarian cancer, and in samples from healthy controls. The mean serum concentration of HE4 was significantly higher in serum samples of patients with both endometrial (99.2 pM, P<0.001) and ovarian (1125.4 pM, P<0.001) cancer but not with ovarian endometriomas (46.0 pM) or other types of endometriosis (45.5 pM) as compared with healthy controls (40.5 pM). The serum CA125 concentrations were elevated in patients with ovarian cancer, advanced endometriosis with peritoneal or deep lesions, or ovarian endometriomas, but not in the patients with endometrial cancer. The microarray results revealed that the mRNA expression of the genes encoding HE4 and CA125 reflected the serum protein concentrations. Taken together, measuring both HE4 and CA125 serum concentrations increases the accuracy of ovarian cancer diagnosis and provides valuable information to discriminate ovarian tumours from ovarian endometriotic cysts.

Ovarian cancer biomarkers: current options and future promise

As more effective, less toxic cancer drugs reach patients, the need for accurate and reliable cancer diagnostics and prognostics has become widely appreciated. Nowhere is this need more dire than in ovarian cancer; here most women are diagnosed late in disease progression. The ability to sensitively and specifically predict the presence of early disease and its status, stage, and associated therapeutic efficacy has the potential to revolutionize ovarian cancer detection and treatment. This article reviews current ovarian cancer diagnostics and prognostics and potential biomarkers that are being studied and validated. Some of the most recent molecular approaches being used to identify genes and proteins are presented, which may represent the next generation of ovarian cancer diagnostics and prognostics.

A serum based analysis of ovarian epithelial tumorigenesis

OBJECTIVES

Ovarian epithelial carcinoma can be subdivided into separate histological subtypes including clear cell, endometrioid, mucinous, and serous. These carcinoma subtypes may represent distinctive pathways of tumorigenesis and disease development. This distinction could potentially be reflected in the levels of tumor produced factors that enter into the circulation and serve as biomarkers of malignant growth. Here, we analyze levels of circulating biomarkers from a diverse set of patients diagnosed with ovarian carcinoma to identify biomarker trends and relationships associated with distinct carcinoma histotypes and divergent tumorigenic pathways.

METHODS

We utilize multiplexed bead-based immunoassays to measure serum levels of a diverse array of fifty-eight biomarkers from the sera of patients diagnosed with various histological subtypes of ovarian carcinoma and benign lesions. The biomarkers studied include cancer antigens, oncogenes, cytokines, chemokines, receptors, growth and angiogenic factors, proteases, hormones, and apoptosis and adhesion related molecules. Levels of each biomarker are compared statistically across carcinoma subtypes as well as with benign cases.

RESULTS

A total of 21 serum biomarkers differ significantly between patients diagnosed with ovarian carcinomas and benign cases. Nine of these biomarkers are specific for carcinomas identified as clear cell, endometrioid, or mucinous in histology, while two biomarkers are specific for the serous histology. In a direct comparison of the histology groups, ten biomarkers are found to be subtype specific. Identified biomarkers include traditional and emerging tumor markers, cytokines and receptors, hormones, and adhesion- and metastasis-related proteins.

CONCLUSIONS

We demonstrate here that the divergent histology-based tumorigenic pathways proposed for ovarian epithelial carcinomas are associated with distinct profiles of circulating biomarkers. Continued investigation into the relationships between these factors should reveal new insights into the complex mechanisms underlying ovarian epithelial tumorigenesis.

Effects of personal characteristics on serum CA125, mesothelin, and HE4 levels in healthy postmenopausal women at high-risk for ovarian cancer

OBJECTIVE

To evaluate if serum levels of candidate ovarian cancer biomarkers vary with individual characteristics of healthy women who are likely candidates for an ovarian cancer screening program.

METHODS

We analyzed serum CA125, mesothelin, and HE4 levels in a sample of 155 healthy postmenopausal women at increased risk for developing ovarian cancer based on personal and family cancer history. Information on reproductive, family and medical histories, lifestyle factors, and anthropometry was collected by self-report. Twenty-two factors were examined using univariate and multiple linear regression models for the three biomarker levels.

RESULTS

In the multivariate models, CA125 levels were significantly higher in women who had used talcum powder (P = 0.02) and were lower in women who were parous (P = 0.05). Mesothelin levels were significantly higher in older women (P = 0.01) and lower in heavier women (P = 0.03). HE4 levels were higher in older women (P = 0.001) and in women who began menstruating at an older age (P = 0.03).

CONCLUSIONS

CA125, mesothelin, and HE4 levels in healthy, postmenopausal women at increased risk for ovarian cancer are significantly associated with a few ovarian cancer risk factors. Since the effects of these personal characteristics on these serum markers are not large, their incorporation in screening algorithms may be unnecessary. This is true especially if a longitudinal algorithm is used because the marker level at the previous screen reflects personal characteristics such as age, body mass index, and age of menarche. Understanding the influence of personal factors on levels of novel early detection markers in healthy, unaffected women may have clinical utility in interpreting biomarker levels.

New insights into the pathogenesis of serous ovarian cancer and its clinical impact

There are only a handful of concepts concerning cancer and carcinogenesis that are currently beyond dispute. One such dogma is the adenoma-carcinoma sequence and that a multistep accumulation of genetic alterations is required for transformation from a benign to a neoplastic tissue. The inevitable derivative of this dogma is that every invasive carcinoma is in fact a missed intraepithelial tumor, and furthermore, a late evolutionary stage in the sequence of development from a precursor lesion. Until fairly recently, high-grade serous ovarian carcinoma seemed to be one of the only known deviants of these concepts. In this article, we discuss the emergence of the fallopian tube fimbria as a field of origin for high-grade serous carcinomas and present a binary model of ovarian cancer pathogenesis that takes into consideration prior epidemiologic, morphologic, and genetic data. With the rise of the fallopian tube secretory epithelial cell as a cell of origin for high-grade pelvic serous carcinomas, the need to develop tools and model systems to characterize the biology and physiology of this cell is recognized.

A novel multiple marker bioassay utilizing HE4 and CA125 for the prediction of ovarian cancer in patients with a pelvic mass

INTRODUCTION

Patients diagnosed with epithelial ovarian cancer (EOC) have improved outcomes when cared for at centers experienced in the management of EOC. The objective of this trial was to validate a predictive model to assess the risk for EOC in women with a pelvic mass.

METHODS

Women diagnosed with a pelvic mass and scheduled to have surgery were enrolled on a multicenter prospective study. Preoperative serum levels of HE4 and CA125 were measured. Separate logistic regression algorithms for premenopausal and postmenopausal women were utilized to categorize patients into low and high risk groups for EOC.

RESULTS

Twelve sites enrolled 531 evaluable patients with 352 benign tumors, 129 EOC, 22 LMP tumors, 6 non EOC and 22 non ovarian cancers. The postmenopausal group contained 150 benign cases of which 112 were classified as low risk giving a specificity of 75.0% (95% CI 66.9-81.4), and 111 EOC and 6 LMP tumors of which 108 were classified as high risk giving a sensitivity of 92.3% (95% CI=85.9-96.4). The premenopausal group had 202 benign cases of which 151 were classified as low risk providing a specificity of 74.8% (95% CI=68.2-80.6), and 18 EOC and 16 LMP tumors of which 26 were classified as high risk, providing a sensitivity of 76.5% (95% CI=58.8-89.3).

CONCLUSION

An algorithm utilizing HE4 and CA125 successfully classified patients into high and low risk groups with 93.8% of EOC correctly classified as high risk. This model can be used to effectively triage patients to centers of excellence.

Conventional and Proteomic Technologies for the Detection of Early Stage Malignancies: Markers for Ovarian Cancer

Our understanding of the tumor microenvironment continues to evolve and allows for the identification of biomarkers that should detect the presence of early stage malignancies. Recent advances in computational analysis and biomedical technologies have come together to elucidate signatures associated with cancer and that are capable of identifying unique tumor-specific proteins. Within the tumor microenvironment, we continue to characterize the proteophysiology of the different steps associated with tumor progression. The urgent need for biomarkers accurately detecting early-stage epithelial ovarian cancer has prompted us, and others, to engage in a search for specific peptide signatures that may discriminate transformed cells from those of the normal ovarian microenvironment. This endeavor also provides new insights into the biology of the disease, which may not only be applicable to detection but may also help to initiate new therapies and optimize patient care.

Use of yeast-secreted in vivo biotinylated recombinant antibodies (Biobodies) in bead-based ELISA

PURPOSE

To measure circulating antigens, sandwich ELISA assays require two complementary affinity reagents. Mouse monoclonal antibodies (mAb) and polyclonal antibodies (pAb) are commonly used, but because their production is lengthy and costly, recombinant antibodies are emerging as an attractive alternative.

EXPERIMENTAL DESIGN

We developed a new class of recombinant antibodies called biobodies (Bb) and compared them to mAb for use in serodiagnosis. Bbs were secreted biotinylated in vivo by diploid yeast and used as affinity reagents after Ni purification. Bead-based assays for HE4 and mesothelin were developed using Bbs in combination with pAbs (Bb/pAb assays). To assess precision, reproducibility studies were done using four runs of 16 replicates at six analyte levels for each marker. Pearson correlations and receiver-operator characteristic analyses were done in 214 patient serum samples to directly compare the Bb/pAb assays to mAb assays. Diagnostic performance of the Bb/pAb assay was further assessed in an expanded set of 336 ovarian cancer cases and controls.

RESULTS

On average across analyte levels, Bb/pAb assays yielded within-run and between-run coefficients of variations of 11.7 and 23.8, respectively, for HE4 and 14.0 and 14.5, respectively, for mesothelin. In the subset (n = 214), Pearson correlations of 0.95 for HE4 and 0.92 for mesothelin were observed between mAb and Bb/pAb assays. The area under the curves for the mAb and Bb/pAb assays were not significantly different for HE4 (0.88 and 0.84, respectively; P = 0.20) or mesothelin (0.74 and 0.72, respectively; P = 0.38).

CONCLUSION

Yeast-secreted Bbs can be used reliably in cost-effective yet highly sensitive bead-based assays for use in large validation studies.

Combining a symptoms index with CA 125 to improve detection of ovarian cancer

BACKGROUND

The current study sought to examine whether an index based on the specific pattern of symptoms commonly reported by women with ovarian cancer could be used in combination with CA 125 to improve the sensitivity or specificity of experimental methods of screening for ovarian cancer.

METHODS

A prospective case-control study design was used. Participants included 254 healthy women at high risk for disease because of family history, and 75 women with ovarian cancer. Logistic regression analysis was used to determine whether the symptom index predicted cancer.

RESULTS

Symptom index information was found to make a significant independent contribution to the prediction of ovarian cancer after controlling for CA 125 levels (P<.05). The combination of CA 125 and the symptom index identified 89.3% of the women with cancer, 80.6% of the early-stage cancers, and 95.1% of the late-stage cancers. The symptom index identified cancer in 50% of the affected women who did not have elevated CA 125 levels. Unfortunately, 11.8% of the high-risk women without cancer also received a positive symptom index score.

CONCLUSIONS

The addition of a symptom index to CA 125 created a composite index with a greater sensitivity for the detection of ovarian cancer than CA 125 alone and identified >80% of women with early-stage disease. A composite marker such as this could serve as a first screen in a multistep screening program in which false-positive findings are identified via transvaginal sonography before referral for surgery, leading to an adequate positive predictive value for the multistep program.

Prediction of ovarian cancer prognosis and response to chemotherapy by a serum-based multiparametric biomarker panel

Currently, there are no effective biomarkers for ovarian cancer prognosis or prediction of therapeutic response. The objective of this study was to examine a panel of 10 serum biochemical parameters for their ability to predict response to chemotherapy, progression and survival of ovarian cancer patients. Sera from ovarian cancer patients were collected prior and during chemotherapy and were analysed by enzyme-linked immunosorbent assay for CA125, kallikreins 5, 6, 7, 8, 10 and 11, B7-H4, regenerating protein IV and Spondin-2. The odds ratio and hazard ratio and their 95% confidence interval (95% CI) were calculated. Time-dependent receiver-operating characteristic (ROC) curves were utilised to evaluate the prognostic performance of the biomarkers. The levels of several markers at baseline (c₀), or after the first chemotherapy cycle (rc₁), predicted chemotherapy response and overall or progression-free survival in univariate analysis. A multiparametric model (c₀ of CA125, KLK5, KLK7 and rc₁ of CA125) provided predictive accuracy with area under the ROC curve (AUC) of 0.82 (0.62 after correction for overfitting). Another marker combination (c₀ of KLK7, KLK10, B7-H4, Spondin-2) was useful in predicting short-term (1-year) survival with an AUC of 0.89 (0.74 after correction for overfitting). All markers examined, except KLK7 and regenerating protein IV, were powerful predictors of time to progression (TTP) among chemotherapy responders. Individual and panels of biomarkers from the kallikrein family (and other families) can predict response to chemotherapy, overall survival, short-term (1-year) survival, progression-free survival and TTP of ovarian cancer patients treated with chemotherapy.

Evaluation of biomarker panels for early stage ovarian cancer detection and monitoring for disease recurrence

OBJECTIVE

To determine the utility of novel combinations of biomarkers, using both a one-step and two-step assay format, to distinguish serum of early ovarian cancer patients from that of healthy controls and to discern the utility of these biomarkers in a monitoring capacity.

METHODS

For ovarian cancer detection, HE4, Glycodelin, MMP7, SLPI, Plau-R, MUC1, Inhibin A, PAI-1, and CA125 were evaluated in a cohort of 200 women with ovarian cancer and 396 healthy age-matched controls. Each biomarker was assessed by serum-based immunoassays utilizing novel monoclonal antibody pairs or commercial kits. For detection of disease recurrence, HE4, Glycodelin, MMP7 and CA125 were evaluated in 260 samples from 30 patients with OC monitored longitudinally after diagnosis.

RESULTS

Based upon ROC curve analysis, the sensitivity/specificity of specific biomarker combination algorithms ranged from 59.0%/99.7% to 80.5%/96.5% for detection of early stage ovarian cancer and 76.9%/99.7% to 89.2%/97.2% for detection of late stage cancer. In monitoring evaluation of 27 patients who experienced recurrence of OC, sensitivity for predicting recurrence was 100% for the biomarker panel and 96% for CA125. At least one of the panel biomarkers was elevated earlier (range 6-69 weeks) than CA125 and prior to clinical evidence of recurrence in 14/27 (52%) patients.

CONCLUSIONS

We have developed and demonstrated the utility of several one- and two-step multi-marker combinations with acceptable test characteristics for possible use in an ovarian cancer screening population. A subset of this panel may also provide adjunctive information to rising CA125 levels in disease monitoring.

A molecular signature of gastric metaplasia arising in response to acute parietal cell loss

BACKGROUND & AIMS

Loss of gastric parietal cells is a critical precursor to gastric metaplasia and neoplasia. However, the origin of metaplasia remains obscure. Acute parietal cell loss in gastrin-deficient mice treated with DMP-777 leads to the rapid emergence of spasmolytic polypeptide/trefoil factor family 2 (TFF2)-expressing metaplasia (SPEM) from the bases of fundic glands. We now sought to characterize more definitively the pathway for emergence of SPEM.

METHODS

Emerging SPEM lineages in gastrin-deficient mice treated with DMP-777 were examined for immunolocalization of TFF2, intrinsic factor, and Mist1, and morphologically with electron microscopy. Emerging SPEM was isolated with laser-capture microdissection and RNA was analyzed using gene microarrays. Immunohistochemistry in mouse and human samples was used to confirm up-regulated transcripts.

RESULTS

DMP-777-induced SPEM was immunoreactive for TFF2 and the differentiated chief cell markers, Mist1 and intrinsic factor, suggesting that SPEM derived from transdifferentiation of chief cells. Microarray analysis of microdissected SPEM lineages induced by DMP-777 showed up-regulation of transcripts associated with G1/S cell-cycle transition including minichromosome maintenance deficient proteins, as well as a number of secreted factors, including human epididymis 4 (HE4). HE4, which was absent in the normal stomach, was expressed in SPEM of human and mouse and in intestinal metaplasia and gastric cancer in human beings.

CONCLUSIONS

Although traditionally metaplasia was thought to originate from normal mucosal progenitor cells, these studies indicate that SPEM evolves through either transdifferentiation of chief cells or activation of a basal cryptic progenitor. In addition, induction of metaplasia elicits the expression of secreted factors, such as HE4, relevant to gastric preneoplasia.

Epithelial ovarian cancer: disease etiology, treatment, detection, and investigational gene, metabolite, and protein biomarkers

Cancer research in recent years has immensely benefited from the development of novel technologies that enable scientists to perform detailed investigations of genomes, transcriptomes, proteomes, and metabolomes. This has invariably furthered knowledge of tumorigenesis and etiology of cancer. The resulting information can, in the foreseeable future, effect a significant change in the pace of cancer research, thereby producing improvements in patient care. Ovarian cancer in particular has received the interest of the scientific community, being the most frequent cause of death from gynecological cancers, characterized by few early symptoms, diagnosis at an advanced stage, as well as poor prognosis. Ovarian cancer is a malignancy in which normal ovarian cells begin to grow in an uncontrolled, abnormal manner and produce tumors in one or both ovaries. Epithelial cancers, the most common ovarian cancers (>80%), develop from cells lining the ovarian surface. Most ovarian cancer research is primarily focused on the early detection and treatment of epithelial ovarian cancer, the more common ovarian malignancy. This review offers an introduction to ovarian cancer, with particular emphasis on human epithelial ovarian cancer. Current methods of detection and therapy are discussed. A survey of promising new protein, gene, and metabolite biomarkers on the horizon is provided. Future prospects for improved diagnosis are offered.

Lessons from BRCA: the tubal fimbria emerges as an origin for pelvic serous cancer

Ovarian epithelial cancer is diagnosed in approximately 25,000 women yearly in the United States, accounting for approximately 12,500 deaths. Of these tumors, serous cancer is the most lethal, due to its capacity to spread beyond the reproductive tract and involve the peritoneal surfaces or distant organs. Conventional classification systems designate tumor origins principally on the location of the largest tumor. However, despite the fact that the largest tumors typically involve the ovaries, demonstrations of a precise starting point for these tumors, including precursor lesions, have been inconsistent. In recent years, a major effort to prevent serous cancer in genetically susceptible women with mutations in BRCA1 or BRCA2 has spawned the practice of prophylactic salpingo-oophorectomy. This practice has surprisingly revealed that many early cancers in these women arise in the fallopian tube, and further studies have pinpointed the distal (fimbrial) portion as the most common site of origin. Emerging studies that carefully examine the fallopian tubes suggest a high frequency of early cancer in the fimbria in unselected women with ovarian and peritoneal serous carcinoma, raising the distinct possibility that a significant proportion of these tumors have a fimbrial origin. The evidence for these discoveries and their relevance to serous cancer classification, early detection and prevention are addressed in this review. A model for pelvic serous cancer is proposed that takes into account five distinct variables which ultimately impact on origin and tumor distribution: (1) location of target epithelium, (2) genotoxic stress, (3) type of epithelium, (4) mitigating genetic factors, and (5) tumor spread pattern. Ultimately, this model illustrates the importance of identifying cancer precursors, inasmuch as these entities are useful as both surrogate endpoints for their respective malignancies in epidemiologic studies and natural targets for cancer prevention.

Novel epididymal protease inhibitors with Kazal or WAP family domain

The epididymal maturation of spermatozoa is regulated by changes in the luminal ion concentration and the processing of the sperm surface membrane by several glycosidases and proteases. In the present study, we identified five novel protease inhibitors that are highly expressed in the mouse epididymis. Four of the proteins were found to belong to the Kazal protease inhibitor family and were named SPINK8, SPINK10, SPINK11, and SPINK12, whereas one of the proteins, WFDC10, contained the WAP four-disulfide core domain structure. The novel genes showed very specific segmental expression patterns. The expression of all the five genes was regulated by testis-derived factors and decreased after gonadectomy. With the exception of Spink11, mRNA levels could be restored by testosterone replacement. We hypothesize that the protease inhibitors discovered represent a group of epididymal genes that contribute to the regulation of sperm maturation by regulating the proteolytic processing of the sperm membrane during epididymal transit.

Congenital heart disease and pregnancy

Patients with congenital heart disease who wish to become pregnant offer a challenge to obstetricians, cardiologists and anesthetists. Although no large randomized trials exist to support the management of this emerging population, small prospective and retrospective studies provide valuable data on the likely success of pregnancy and the risks involved. Recently, there is emerging consensus on the management of this specialized group of patients, and this article aims to provide the practitioner with an overview of patient needs and the issues to be addressed. All patients with congenital heart disease wishing to consider pregnancy should be referred for specialist assessment prior to conception. Maternal risk, fetal risk and recurrence risk in the fetus should all be addressed. Most women with congenital heart disease can undergo pregnancy without significant risk. However, for some women the risk of maternal death is high, including those with: severe aortic stenosis, impaired left ventricular function, pulmonary hypertension and Marfan syndrome with dilated aortic root. All patients should be offered a detailed 20-week fetal cardiac scan and, in certain cases, prepregnancy genetic counseling. Most patients can deliver vaginally, with cesarean section reserved for obstetric indications or patients in whom straining at delivery could be potentially fatal (i.e., those with Marfan syndrome, aortic aneurysm, severe fixed left heart obstruction, or the acutely unwell mother). Antibiotic prophylaxis should be given routinely in labor to all patients in whom dental prophylaxis is indicated.

Bead-based ELISA for validation of ovarian cancer early detection markers

PURPOSE

Efforts to validate ovarian cancer early detection biomarkers with immunoassays are challenged by the limited specimen volumes available. We sought to develop a specimen-efficient assay to measure CA125 in serum, assess its reproducibility, validity, and performance, and test its potential for multiplexing and combining with human epididymis protein 4 (HE4), a promising novel ovarian cancer marker.

EXPERIMENTAL DESIGN

Four pairs of commercially available anti-CA125 antibodies and one pair of anti-HE4 antibodies were evaluated for accuracy in measuring known concentrations of antigen on a bead-based platform. The two best pairs were further assessed for reproducibility, validity, and the ability to discriminate between blinded serum samples obtained from ovarian cancer cases (n = 66) and women without ovarian cancer (n = 125).

RESULTS

Suitability for use in a bead-based assay varied across CA125 antibody pairs. Two CA125 bead-based assays were highly reproducible (overall correlations between replicates >/= 0.95; coefficients of variation < 0.2) and strongly correlated with the research standard CA125II RIA (correlations >/= 0.9). Their ability to distinguish ovarian cancer cases from non-cases based on receiver operating characteristic analyses (area under the curve, AUC, of 0.85 and 0.84) was close to that of the CA125II RIA (AUC, 0.87). The HE4 bead-based assay showed lower reproducibility but yielded an AUC of 0.89 in receiver operating characteristics analysis. Multiplexing was not possible but a composite marker including CA125 and HE4 achieved an AUC of 0.91.

CONCLUSION

Optimization procedures yielded two bead-based assays for CA125 that perform comparably to the standard CA125II RIA, which could be combined with an HE4 bead-based assay to improve diagnostic performance, and requires only 15 muL of sample each.

Comprehensive analysis of HE4 expression in normal and malignant human tissues

The HE4 (WFDC2) gene encodes a WAP-type four disulphide core domain-containing protein with a presumptive role in natural immunity. Multiple studies have consistently identified upregulation of HE4 gene expression in carcinomas of the ovary; however, the expression in normal and malignant adult tissues has not been examined in detail. Here, we examined the expression of the HE4 gene and protein in a large series of normal and malignant adult tissues by oligonucleotide microarray and tissue microarray, respectively. HE4 gene expression was highest in normal human trachea and salivary gland, and to a lesser extent, lung, prostate, pituitary gland, thyroid, and kidney. In a series of 175 human adult tumors, gene expression was highest in ovarian serous carcinomas. However, adenocarcinomas of the lung, and occasional breast, transitional cell and pancreatic carcinomas had moderate or high levels of HE4 expression. Using tissue microarrays and full tissue sections of normal and 448 neoplastic tissues, HE4 immunoreactivity was found in normal glandular epithelium of the female genital tract and breast, the epididymis and vas deferens, respiratory epithelium, distal renal tubules, colonic mucosa, and salivary glands, consistent with HE4 gene expression. In addition to consistent positivity in ovarian carcinoma, some pulmonary, endometrial, and breast adenocarcinomas, mesotheliomas, and less often, gastrointestinal, renal and transitional cell carcinomas were also positive. Knowledge of the expression patterns of HE4 in our survey is useful for application in histopathologic diagnosis, and should be taken into consideration in future studies that examine the role of HE4 as a serological tumor biomarker or as a target for gene-based therapy.

WFDC2 (HE4): a potential role in the innate immunity of the oral cavity and respiratory tract and the development of adenocarcinomas of the lung

Background

The Whey Acidic Protein domain is an evolutionarily conserved motif found in a number of proteins, the best studied of which are antiproteinases involved in the innate immune defence of multiple epithelia. We recently characterised the WFDC2 gene which encodes a two WAP domain-containing protein, initially suggested as a marker for epididymis, and showed that it is highly expressed in the lung and salivary gland. The precise location of WFDC2 protein in these sites has not been described.

Methods

We used immunohistochemistry to localise WFDC2 in normal tissues of the respiratory tract, naso- and oropharynx, as well as in chronically inflamed lung from Cystic Fibrosis and a range of pulmonary carcinomas. We have complemented these studies with molecular analysis of WFDC2 gene expression in primary human lung cell cultures.

Results

WFDC2 is expressed in some epithelial cells of the upper airways as well as in mucous cells and ducts of submucosal glands. No staining was seen in peripheral lung. Intense staining is found in major salivary glands and in minor glands of the nose, sinuses, posterior tongue and tonsil. Studies with the related protein Secretory Leukocyte Protease Inhibitor (SLPI) show that although both proteins are expressed in similar tissues, the precise cellular localisation differs. Significant increases in expression and localisation of WFDC2 are seen in patients with Cystic Fibrosis. SLPI expression was greatly reduced in the same samples. In cultures of tracheobronchial epithelial cells, expression of WFDC2 and SLPI are differentially regulated during differentiation yet WFDC2 is not induced by pro-inflammatory mediators. The majority of adenocarcinomas stain with WFDC2 whilst a significant minority of squamous, small cell and large cell carcinomas exhibit focal staining. There is no clear association with tumour grade.

Conclusion

We believe that these studies support the hypothesis that WFDC2 may be a component of the innate immune defences of the lung, nasal and oral cavities and suggest that WFDC2 functions in concert with related WAP domain containing proteins in epithelial host defence. We also suggest that WFDC2 re-expression in lung carcinomas may prove to be associated with tumour type and should be studied in further detail.

Proteins with whey-acidic-protein motifs and cancer

The importance of early diagnosis to reduce the morbidity and mortality from cancer has led to a search for new sensitive and specific tumour markers. Molecular techniques developed over the past few years allow simultaneous screening of thousands of genes, and have been applied to different cancers to identify many genes that are modulated in various cancers. Of these, attention has focused on genes coding for a family of proteins with whey-acidic-protein (WAP) motifs. Most notably, the genes coding for elafin, antileukoproteinase 1 (previously called secretory leucocyte proteinase inhibitor, SLPI), WAP four disulphide core domain protein 1 (previously called prostate stromal protein 20 kDa, PS20), and WAP four disulphide core domain protein 2 (previously called major human epididymis-specific protein E4, HE4), have been identified as candidate molecular markers for several cancers. In this review, we assess data for an association between cancer and human WAP proteins, and discuss their potential role in tumour progression. We also propose a new mechanism by which WAP proteins might have a role in carcinogenesis.

B7-h4 is a novel membrane-bound protein and a candidate serum and tissue biomarker for ovarian cancer

Using cDNA database mining strategies and real-time quantitative reverse transcription-PCR, we identified B7-H4 as a novel gene that is overexpressed in ovarian and breast cancer tissues when compared with normal tissues. The gene encodes a protein of 282 amino acids with a signal sequence, an immunoglobulin domain, and a COOH-terminal hydrophobic transmembrane domain. Immunohistochemistry experiments show plasma membrane staining in serous ovarian and breast cancer, confirming the tissue specificity and cell surface localization. We have developed a sensitive dual monoclonal antibody sandwich ELISA to analyze the level of B7-H4 protein in >2,500 serum samples, ascites fluids, and tissue lysates. High levels of B7-H4 protein were detected in ovarian cancer tissue lysates when compared with normal tissues. B7-H4 was present at low levels in all sera but showed an elevated level in serum samples from ovarian cancer patients when compared with healthy controls or women with benign gynecologic diseases. The median B7-H4 concentration in endometrioid and serous histotypes was higher than in mucinous histotypes, consistent with results of immunohistochemical staining. The multivariate logistic regression analysis of B7-H4 and CA125 measured in the same sample set resulted in an area under the curve (AUC) of 0.86 for all stages and 0.86 for stage I/II patients, which was significantly higher than the AUC for either marker alone. In early-stage patients, the sensitivity at 97% specificity increased from 52% for CA125 alone to 65% when used in combination with B7-H4. We conclude that B7-H4 is a promising new biomarker for ovarian carcinoma.

High resolution analysis of genomic aberrations by metaphase and array comparative genomic hybridization identifies candidate tumour genes in lung cancer cell lines

Tumours develop from clonally expanded population of cells harbouring aberrations of oncogenes and tumour suppressor genes. In this study, metaphase and array comparative genomic hybridization showed good correlation of aberration profiles in lung adenocarcinoma cell lines from patients with different tobacco exposure. Recurrent DNA gains were found at chromosomes 1, 7, 8, 17, 20, and deletions at 1, 3, 8, 9, 10, 12, 17, 18, 19. Candidate tumour loci and encompassed genes at 7p21 (AGR2), 8q21(TPD52), 20q13 (ZNF217, WFDC2, EEF1A2) and 10p15 (KLF6) were analyzed by dual colour FISH for genomic changes and quantitative PCR for expression changes. Results indicated that EEF1A2 and KLF6 were strong candidates of oncogene and tumour suppressor genes, respectively. This study illustrates, a practical strategy for identifying candidate cancer genes from microarray data.

The role of proteomics in the diagnosis and treatment of ovarian cancer

Ovarian cancer is the leading cause of gynecologic cancer death in the Western world and more than 70% of patients are diagnosed with advanced stage disease. The high mortality rate is due to the difficulty in the early detection of ovarian cancer. Current screening strategies lack the necessary sensitivity and specificity to reliably and accurately diagnose affected women, prompting investigators to seek alternative means of analysis found in protein pathways and networks. Proteomics seeks to advance the understanding of how proteins interact in cancer and may provide a mechanism for early stage diagnosis. The proteomic techniques of laser capture microdissection, mass spectrometry and tissue lysate arrays have led to the discovery of new biomarkers and the identification, development and approval of a number of targeted therapeutic agents. Following validation through clinical trials, the application of these techniques will contribute to the changing paradigm of cancer detection and treatment toward personalized medicine.