Biomarkers of ovarian tumours

The challenging screen detection of ovarian cancer in BRCA mutation carriers adhering to a 6-month follow-up program: results from a 6-years surveillance

OBJECTIVE

Approximately 25% of ovarian cancer (OC) cases are related to an inherited predisposition. Genetic mutations for the oncosuppressor genes BRCA1 and 2 have the best-known linkage to a higher incidence of OC and breast cancer, in approximately 70% to 80% of hereditary OC cases. To provide the first comprehensive clinical description of screen-detected (SD) OCs during a 6-years surveillance of a cohort of young BRCA carriers and carriers who refuse risk-reducing salpingo-oophorectomy.

METHODS

A prospective cohort study in a university hospital describing 191 women with BRCA1 and 2 mutations adhering continuously to our surveillance between 2015 and 2020, including a 6-monthly evaluation of cancer antigen 125 (CA 125) with concomitant transvaginal ultrasound (TVUS) performed by a dedicated specialist. Main outcomes were tumor's laterality, CA 125 at diagnosis, TVUS and computed tomography (CT) findings.

RESULTS

Risk-reducing salpingo-oophorectomy was performed in 58/191 (30.4%) of mutation carriers during the study period (one OC case identified). Nine SD-OCs and no interval OCs were found in the remaining 133 women. OCs (FIGO stage I or II: 88.9%) occur mainly in BRCA 1 (77.8%), being bilateral in 85.7% BRCA 1 and unilateral in 100% BRCA 2. No lesions involved only the tubes: left ovaries/tubes were more frequently involved. We have described three new possible scenarios regarding imaging: 1) Evident cases (33.3%, TVUS and CT obvious for OC, CA 125 sensitivity: 100%), 2) Possible cases (55.6%, TVUS and CT are in general accordance, documenting new TVUS signs: increased solid pattern of the ovary with peripheral cortical small cysts, hypoechoic circular mass near the ovary, intraparenchymal small hyperechoic foci), and 3) Hidden cases (11.1%, the smallest lesion but the highest stage (IIIA2), with CA 125 44.2 U/mL and concomitant endometrial hyperplasia).

CONCLUSIONS

Different diagnostic tools must integrate to ensure early diagnosis of OC in BRCA mutation carriers adhering to a follow-up program.

Wilms' tumor 1 (WT1) as a prognosis factor in gynecological cancers: A meta-analysis

The oncogenic role of Wilms' tumor 1 (WT1) which is regarded as a promising target antigen for cancer immunotherapy has been demonstrated in many types of cancer, but the relationship between expression of WT1 and the prognosis value in gynecological cancer reminds unclear.We performed a meta-analysis with thirteen published studies including 2205 patients searched from PubMed, EMBASE, Web of Science, and Google Scholar, whose results are expressed by overall survival (OS) or disease-specific survival (DSS) or disease-free survival or relapse/recurrence-free survival (RFS) or progression-free survival (PFS) in patients with gynecological cancer. The hazard ratio (HR) with its 95% confidence interval (CI) were calculated to investigate prognostic of WT1 expression in patients with gynecological cancer.Finally, the overexpression of WT1 was borderlinely associated with poor OS (metaHR = 1.51, 95% CI = 0.98-2.31) in univariate model. We found a significant association with poor DSS (metaHR = 1.61, 95% CI = 1.24-2.08) and DFS/RFS/PFS (metaHR = 2.06, 95% CI = 1.22-3.46). The subgroup analyses revealed that the expression of WT1 predicted the poor DSS (metaHR = 1.82, 95% CI = 1.42-2.73), and DFS/RFS/PFS (metaHR = 2.51, 95% CI = 1.81-3.48) in patients with ovarian cancer. In summary, WT1 overexpression indicates a poor prognosis in patients with some gynecological tumors, but more studies are needed to confirm these findings.

Identification of new genes associated to senescent and tumorigenic phenotypes in mesenchymal stem cells

Although human mesenchymal stem cells (hMSCs) are a powerful tool for cell therapy, prolonged culture times result in replicative senescence or acquisition of tumorigenic features. To identify a molecular signature for senescence, we compared the transcriptome of senescent and young hMSCs with normal karyotype (hMSCs/n) and with a constitutional inversion of chromosome 3 (hMSC/inv). Senescent and young cells from both lineages showed differentially expressed genes (DEGs), with higher levels in senescent hMSCs/inv. Among the 30 DEGs in senescent hMSC/inv, 11 are new candidates for biomarkers of cellular senescence. The functional categories most represented in senescent hMSCs were related to cellular development, cell growth/proliferation, cell death, cell signaling/interaction, and cell movement. Mapping of DEGs onto biological networks revealed matrix metalloproteinase-1, thrombospondin 1, and epidermal growth factor acting as topological bottlenecks. In the comparison between senescent hMSCs/n and senescent hMSCs/inv, other functional annotations such as segregation of chromosomes, mitotic spindle formation, and mitosis and proliferation of tumor lines were most represented. We found that many genes categorized into functional annotations related to tumors in both comparisons, with relation to tumors being highest in senescent hMSCs/inv. The data presented here improves our understanding of the molecular mechanisms underlying the onset of cellular senescence as well as tumorigenesis.

Impact of Preoperative Serum Levels of CA 125 on Epithelial Ovarian Cancer Survival

BACKGROUND

CA125 is very helpful in treatment monitoring and detection of epithelial ovarian cancer (EOC) recurrence. However there is controversy as to its accuracy and optimal usage. What is the impact of the CA125 levels before primary surgery treatment to the survival of patients? This study aimed to detect any association of preoperative serum levels with prognosis and survival in EOC patients.

MATERIALS AND METHODS

Our cohort comprised EOC patients in Dr. Sardjito Hospital, Yogyakarta, Indonesia, who complied with follow up. To explore the effect of preoperative CA125 levels and other variables on survival Cox's regression models were applied.

RESULTS

A total of 90 cases of EOC who had surgery were available for follow up. The level of CA125 poroved to be a prognostic factor for overall survival of EOC patients, with an adjusted HR of 4.10 (p = 0.03). Adjuvant chemotherapy was another prognostic factor, 1 - 2 cycles having an adjusted HR of 0.17 (p = 0.04) and 3 - 8 cycles HR 0.39 (p = 0.06). Other factors such as age of patients adjusted HR 1.54 (p = 0.32), moderate differentiation (adjusted HR 1.61, p = 0.51) poor differentiation (adjusted HR 3.41, p = 0.15), and stage of disease (adjusted HR 1.98, p = 0.27) were statistically not significant. However, this might have been because the power of the study was low.

CONCLUSIONS

Preoperative level of CA125 is a prognostic factor for overall survival in EOC patients. The best cut-off for prognostic classification of CA125 serum level is 70 U/ml.

Evolving Role of Serum Biomarkers in the Management of Ovarian Cancer

The availability of an ideal serum tumor marker would be of great clinical benefit for both the diagnosis and management of patients with epithelial ovarian cancer. Serum cancer antigen 125 assay significantly increases the diagnostic reliability of ultrasound in discriminating a malignant from a benign ovarian mass, especially in postmenopausal women, and it is the only well validated tumor marker for monitoring disease course. Several other tumor-associated antigens have been assessed, including glycoprotein antigens other than cancer antigen 125, soluble cytokeratin fragments, kallikreins, cytokines and cytokine receptors, vascular endothelial growth factor, D-dimer, and lisophosphatidic acid. This article assesses the potential diagnostic and prognostic role of these novel biomarkers, both alone and in combination with cancer antigen 125. The future for serum tumor marker research is represented by the emerging technology of proteomics, which may allow scientific advances comparable to those achieved with the introduction of monoclonal antibody technology.

Macranthoside B Induces Apoptosis and Autophagy Via Reactive Oxygen Species Accumulation in Human Ovarian Cancer A2780 Cells

Macranthoside B (MB), a saponin compound in Lonicera macranthoides, can block cell proliferation and induce cell death in several types of cancer cells; however, the precise mechanisms by which MB exerts its anticancer effects remain poorly understood. MB blocked A2780 human ovarian carcinoma cell proliferation both dose- and time-dependently. MB induced apoptosis, with increased poly (ADP-ribose) polymerase (PARP) and caspase-3/9 cleavage. MB also caused autophagy in A2780 cells, with light chain 3 (LC3)-II elevation. Inhibiting MB-induced autophagy with the autophagy inhibitor 3-methyladenine (3-MA) significantly decreased apoptosis, with a reduction of growth inhibition; inhibiting MB-induced apoptosis with the pan-caspase inhibitor Z-VAD-FMK did not decrease autophagy but elevated LC3-II levels, indicating that MB-induced autophagy is cytotoxic and may be upstream of apoptosis. Furthermore, MB increased intracellular reactive oxygen species (ROS) levels, with activated 5' adenosine monophosphate-activated protein kinase (AMPK), decreased mammalian target of rapamycin (mTOR) and P70S6 kinase phosphorylation, and increased PARP and caspase-3/9 cleavage, and LC3-II elevation; treatment with the ROS scavenger N-acetyl cysteine and the AMPK inhibitor Compound C diminished this effect. Therefore, the ROS/AMPK/mTOR pathway mediates the effect of MB on induction of apoptosis via autophagy in human ovarian carcinoma cells.

Tetranectin positive expression in tumour tissue leads to longer survival in Danish women with ovarian cancer. Results from the 'Malova' ovarian cancer study

The primary objective of this study was to analyse Tetranectin (TN) expression in tumour tissues and TN serum concentration in 758 women with epithelial ovarian tumours. The second was to evaluate, whether TN tissue expression levels correlate with clinico-pathological parameters and prognosis of the disease. Using tissue arrays we analysed the expression levels in tissues from 166 women with borderline ovarian tumours (BOTs) and 592 women with ovarian cancer (OC). A panel of three antibodies was used for immunohistochemistry: a polyclonal and two monoclonal antibodies. Serum TN was measured using the polyclonal antibody A-371. Univariate survival analyses stratified for chemotherapy showed that positive tissue TN as demonstrated by the polyclonal antibody indicated a significantly longer overall survival (OS) (p = 0.0001) as well as cancer specific survival (CSS) (p < 0.0001). High serum TN was likewise found to imply longer OS (p < 0.0001) and CSS (p < 0.0001), whereas tissue staining with the two monoclonal antibodies failed to demonstrate any significant correlation with either survival type. Univariate Kaplan-Meier survival analysis performed on all OC cases showed a significantly longer OS (p = 0.0009) and CSS (p = 0.0006) for women with TN positive tumour tissue and in women with high serum TN levels (p < 0.0001 for both). However, in the multivariate Cox regression analysis, only serum TN was found to be an independent prognostic factor for OS (p = 0.01) and not for CSS (p = 0.08). In conclusion, our results predict that a positive TN expression of both tumour tissue and serum points to a more favourable outcome for OC patients.

Role of sonography in the diagnostic workup of ovarian and adnexal masses except in pregnancy and during ovarian stimulation

The main role of imaging is to provide a description of the appearance, size, and location of adnexal lesions and associated abnormalities. In some circumstances, the aggressive potential of an adnexal lesion may be suggested on the basis of the imaging findings, the age of the patient, and the clinical data.

Limited prognostic value of tissue protein expression levels of cyclin E in Danish ovarian cancer patients: from the Danish 'MALOVA' ovarian cancer study

The primary objective of this study was to assess the expression of cyclin E in tumour tissues from 661 patients with epithelial ovarian tumours. The second was to evaluate whether cyclin E tissue expression levels correlate with clinico-pathological parameters and prognosis of the disease. Using tissue arrays (TA), we analysed the cyclin E expression levels in tissues from 168 women with borderline ovarian tumours (BOT) (147 stage I, 4 stage II, 17 stage III) and 493 Ovarian cancer (OC) patients (127 stage I, 45 stage II, 276 stage III, 45 stage IV). Using a 10% cut-off level for cyclin E overexpression, 20% of the BOTs were positive with a higher proportion of serous than mucinous tumours. Sixty-two per cent of the OCs were positive for cyclin E expression with the highest percentage found in clear cell carcinomas. Results based on univariate and multivariate survival analyses with a 10% cut-off value showed that cyclin E had no independent prognostic value. In conclusion, we found cyclin E expression in tumour tissue to be of limited prognostic value to Danish OC patients.

Thrombopoietin: a novel candidate tumor marker for the diagnosis of ovarian cancer

Objective

To investigate the decisive role of preoperative serum thrombopoietin levels in the discrimination of benign and malignant ovarian pathologies and its value in the evaluation of treatment response.

Methods

Fifty patients with diagnoses of adnexal masses (25 benign, 25 malignant) were included in the study. Blood samples were collected from all cases preoperatively. Age, menopausal status, adnexal mass size, preoperative CA-125 level, platelet count, the stage of the disease (FIGO stage), tumor grade, histologic subgroup, the residual tumor mass, ascites cytology, surgical procedures, and postoperative treatments were recorded for the malignant group. Response to treatment was evaluated based on the revised RECIST guideline.

Results

The preoperative serum thrombopoietin levels of the malignant cases (median, 98; range, 7 to 768) were significantly higher when compared with those of benign cases (median, 27; range, 13 to 131; p=0.004). The positive predictive value of CA-125 was found to be 79%, when it was used as a single marker; however it had risen to 85% when both CA-125 and thrombopoietin levels were used. There was no significant relationship between preoperative serum thrombopoietin levels and tumor grade, ascites cytology, presence of residual mass, and response to treatment. The preoperative serum thrombopoietin levels were significantly higher in stage III-IV cases and cases with serous histology. The post-treatment serum thrombopoietin levels in the malignant group were significantly lower as compared with the preoperative thrombopoietin levels.

Conclusion

Thrombopoietin can play an additive role for prediction of ovarian cancer.

Acacetin inhibits VEGF expression, tumor angiogenesis and growth through AKT/HIF-1α pathway

Acacetin (5,7-dihydroxy-4'-methoxyflavone) is a flavone compound, some of which have anti-cancerous effects. Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis and tumor growth. In this study, we found that acacetin decreased the steady level of VEGF mRNA level and inhibited VEGF transcriptional activation. To further determine the potential mechanism of acacetin in inhibiting VEGF expression, we showed that acacetin inhibited HIF-1α expression and AKT activation. Over-expression of HIF-1α or AKT restored acacetin-decreasing VEGF transcriptional activation, indicating that AKT and HIF-1 are the essential downstream targets of acacetin for inhibiting VEGF expression in the cells. Moreover, acacetin significantly inhibited ovarian cancer cell-induced angiogenesis and tumor growth in vivo through inhibiting HIF-1α and VEGF expression. Acacetin did not change HIF-1α mRNA level, but inhibited HIF-1α protein level through increasing its degradation and decreasing its stability. These results indicate that acacetin may be a useful natural compound for ovarian cancer prevention and treatment.

Identification of β2-microglobulin as a urinary biomarker for chronic allograft nephropathy using proteomic methods

PURPOSE

Chronic allograft nephropathy (CAN) remains the leading cause of renal graft loss after the first year following renal transplantation. This study aimed to identify novel urinary proteomic profiles, which could distinguish and predict CAN in susceptible individuals.

EXPERIMENTAL DESIGN

The study included 34 renal transplant patients with histologically proven CAN and 36 patients with normal renal transplant function. High-throughput proteomic profiles were generated from urine samples with three different ProteinChip arrays by surface-enhanced laser-desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Following SELDI, a biomarker pattern software analysis was performed which led to the identification of a novel biomarker pattern that could distinguish patients with CAN from those with normal renal function.

RESULTS

An 11.7 kDa protein identified as β2 microglobulin was the primary protein of this biomarker pattern, distinguishing CAN from control patients (receiver operator characteristic [ROC]=0.996). SELDI-TOF-MS comparison of purified β2 microglobulin protein and CAN urine demonstrated identical 11.7 kDa protein peaks. Significantly, higher concentrations of 2 microglobulin were found in the urine of patients with CAN compared with the urine of normal renal function transplant recipients (p<0.001).

CONCLUSIONS AND CLINICAL RELEVANCE

Although further validation in a larger more diverse patient population is required to determine if this β2 microglobulin protein biomarker will provide a potential means of diagnosing CAN by noninvasive methods in a clinical setting, this study clearly shows a capability to stratify control and disease patients.

Proteomic biomarkers for overall and progression-free survival in ovarian cancer patients

PURPOSE

To determine if the level of apolipoprotein A1, hepcidin, transferrin, inter-α trypsin IV internal fragment, transthyretin (TT), connective-tissue activating protein 3 (CTAP3), serum amyloid A1, β-2 microglobulin (B2M) might have impact on overall and progression-free survival for ovarian cancer (OC) patients.

EXPERIMENTAL DESIGN

Serum from 150 OC patients was tested using SELDI-TOF-MS.

RESULTS

A proteomic prognostic index (xb-pro) was constructed using the regression coefficients based on inter-α trypsin IV internal fragment, B2M and TT. A multivariable Cox survival analysis including the xb-pro index showed that xb-pro (p<0.0001, HR=2.50, 95% CI: 1.65-3.79), residual tumor after primary surgery (p=0.0005), age (p=0.01) and chemotherapy (p=0.0002) are of independent prognostic value for overall survival. International Federation of Gynecology and Obstetrics stage, performance status, histological type of tumor and serum CA125 were found of no independent value. A proteomic index (xb-pfs) based on B2M and CTAP3 was found to predict progression-free survival (xb-pfs: p=0.008, HR=1.77, 95% CI: 1.17-2.70 together with type of surgery, age and chemotherapy.

CONCLUSIONS AND CLINICAL RELEVANCE

We found an index with three proteomic biomarkers (xb-pro) to be of independent prognostic value for overall survival and an index with two proteomic biomarkers (xb-pfs) with evidence of independent prognostic value for progression-free survival.

Patients with ovarian carcinoma excrete different altered levels of urine CD59, kininogen-1 and fragments of inter-alpha-trypsin inhibitor heavy chain H4 and albumin

Background

Diagnosis of ovarian carcinoma is in urgent need for new complementary biomarkers for early stage detection. Proteins that are aberrantly excreted in the urine of cancer patients are excellent biomarker candidates for development of new noninvasive protocol for early diagnosis and screening purposes. In the present study, urine samples from patients with ovarian carcinoma were analysed by two-dimensional gel electrophoresis and the profiles generated were compared to those similarly obtained from age-matched cancer negative women.

Results

Significant reduced levels of CD59, kininogen-1 and a 39 kDa fragment of inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), and enhanced excretion of a 19 kDa fragment of albumin, were detected in the urine of patients with ovarian carcinoma compared to the control subjects. The different altered levels of the proteins were confirmed by Western blotting using antisera and a lectin that bind to the respective proteins.

Conclusion

CD59, kininogen-1 and fragments of ITIH4 and albumin may be used as complementary biomarkers in the development of new noninvasive protocols for diagnosis and screening of ovarian carcinoma.

Serum S100A6 concentration predicts peritoneal tumor burden in mice with epithelial ovarian cancer and is associated with advanced stage in patients

BACKGROUND

Ovarian cancer is the 5th leading cause of cancer related deaths in women. Five-year survival rates for early stage disease are greater than 94%, however most women are diagnosed in advanced stage with 5 year survival less than 28%. Improved means for early detection and reliable patient monitoring are needed to increase survival.

METHODOLOGY AND PRINCIPAL FINDINGS

Applying mass spectrometry-based proteomics, we sought to elucidate an unanswered biomarker research question regarding ability to determine tumor burden detectable by an ovarian cancer biomarker protein emanating directly from the tumor cells. Since aggressive serous epithelial ovarian cancers account for most mortality, a xenograft model using human SKOV-3 serous ovarian cancer cells was established to model progression to disseminated carcinomatosis. Using a method for low molecular weight protein enrichment, followed by liquid chromatography and mass spectrometry analysis, a human-specific peptide sequence of S100A6 was identified in sera from mice with advanced-stage experimental ovarian carcinoma. S100A6 expression was documented in cancer xenografts as well as from ovarian cancer patient tissues. Longitudinal study revealed that serum S100A6 concentration is directly related to tumor burden predictions from an inverse regression calibration analysis of data obtained from a detergent-supplemented antigen capture immunoassay and whole-animal bioluminescent optical imaging. The result from the animal model was confirmed in human clinical material as S100A6 was found to be significantly elevated in the sera from women with advanced stage ovarian cancer compared to those with early stage disease.

CONCLUSIONS

S100A6 is expressed in ovarian and other cancer tissues, but has not been documented previously in ovarian cancer disease sera. S100A6 is found in serum in concentrations that correlate with experimental tumor burden and with clinical disease stage. The data signify that S100A6 may prove useful in detecting and/or monitoring ovarian cancer, when used in concert with other biomarkers.

Role of CA125 in predicting ovarian cancer survival - a review of the epidemiological literature

CA125 is the gold standard tumor marker in ovarian cancer. Serum level of CA125 is used to monitor response to chemotherapy, relapse, and disease progression in ovarian cancer patients. Thus, it is reasonable to investigate whether CA125 may have utility as a prognostic indicator as well in ovarian cancer. A large number of epidemiological studies have been carried out to this effect. This review summarizes all available epidemiological literature on the association between CA125 levels and survival in ovarian cancer. To place these studies in context, we provide some background information on CA125 and its role in ovarian cancer.

Correlation between preoperative serum levels of five biomarkers and relationships between these biomarkers and cancer stage in epithelial overian cancer

OBJECTIVE

To examine the correlation among the preoperative serum levels of five biomarkers presumed to be useful for early detection of epithelial ovarian cancer and evaluate the relationships between serum levels of these five biomarkers and epithelial ovarian cancer stage.

METHODS

We analyzed 56 newly diagnosed epithelial ovarian cancer patients. Preoperative serum levels of leptin, prolactin, osteopontin (OPN), insulin-like growth factor-II, and CA-125 were determined by ELISA. We also examined the correlation between the serum levels of the biomarkers and ovarian cancer stage. Significant differences in the mean serum levels of two proteins, leptin and CA-125, were observed between stage subsets.

RESULTS

There was a significant negative correlation between prolactin and leptin and a significant positive correlation between prolactin and OPN. Of the five biomarkers, only the mean serum CA-125 level showed a significant positive correlation with cancer stage (Spearman rho=0.24, p<0.01). OPN showed a marginally significant positive correlation with stage (Spearman rho=0.14, p=0.07).

CONCLUSION

We demonstrated the relationship between five biomarkers in epithelial ovarian cancer. These tumor markers may be useful in screening for ovarian cancer, in characterizing disease states, and in developing therapeutic interventions targeting these marker proteins. Large-scale studies that include potential confounding factors and modifiers are necessary to more accurately define the value of these novel biomarkers in ovarian cancer.

Protein expression levels of carcinoembryonic antigen (CEA) in Danish ovarian cancer patients: from the Danish 'MALOVA'ovarian cancer study

AIMS

To determine the variation in expression of carcinoembryonic antigen (CEA) in 760 epithelial ovarian tumours from Denmark, and to correlate expression with clinicopathological parameters and prognosis for the disease.

METHODS

Using tissue arrays (TA), we analysed CEA expression in tissues from 189 women diagnosed with low malignant potential ovarian tumours (LMP, borderline ovarian tumours) and 571 women diagnosed with ovarian cancer (OC).

RESULTS

Using 30% as the cut-off level for CEA over-expression, 18% of LMPs and 4% of OCs were positive. A higher proportion of mucinous tumours were positive compared with other histological subtypes (p<0.00001). A univariate survival analysis suggested a shorter disease specific survival for patients with 30% or higher CEA expression in the tumour tissue (p = 0.004). In a Cox survival analysis, which included 569 OC cases subgrouped by stage (I to IV), the highest CEA expression compared with no expression was found to be a prognostic factor (level 3 versus negative: HR = 2.12, 95%CI 1.11-4.05). FIGO stage, residual tumour after primary surgery, age at diagnosis, other histological types versus serous adenocarcinoma and low versus high histological grade tumours were also prognostic factors.

CONCLUSION

These data suggest that CEA expression is an independent prognostic factor for mucinous OC in Danish patients.

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

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

Cancer antigen 125 and prognosis

PURPOSE OF REVIEW

This review addresses recently reported progress in cancer antigen 125 as a prognostic marker in patients with ovarian cancer.

RECENT FINDINGS

Serum cancer antigen 125 levels measured preoperatively in both early and late stage ovarian cancer may be of prognostic value. Before cancer antigen 125 determination may be implemented into clinical practice, cut-off levels must be evaluated and internationally defined. Studies examining serum cancer antigen 125 levels after surgery but before, during, or after treatment confirmed that changes in serum levels are of prognostic value. Furthermore, recent studies have shown that the level of expression of cancer antigen 125 in tissue may be an independent prognostic indicator in late stage ovarian cancer.

SUMMARY

Prognostic markers may potentially help to individualize treatment within subgroups of patients. In a recent study the level of cancer antigen 125 expression was consistently found to be of prognostic value. This finding supports implementation of cancer antigen 125 measurement in future clinical ovarian cancer trials to clarify whether this marker has value in selecting candidates for individually based treatments.

Contemporary progress in ovarian cancer screening

Our limited understanding of the natural biology of ovarian cancer, along with its low prevalence in the general population make early detection especially challenging. To be successful at the population level, an ovarian cancer screening test must prove its beneficial effect on ovarian cancer-specific mortality while achieving near-perfect specificity in order to minimize the harms resulting from false-positive results. No current screening tests for ovarian cancer fulfill these expectations. We review the current status and the challenges of ovarian cancer screening in the context of evidence-based principles that define a valuable cancer screening program.

Glycans as a Target in the Detection of Reproductive Tract Cancers

The significance of changes in glycosylation for the beginning, progress and outcome of different human diseases is highly recognized. In this review we summarized literature data on the alteration of glycans in cancer, especially glycoforms of tumor markers of reproductive tract cancers: prostate-specific antigen (PSA) and cancer antigen 125 (CA125). We aimed to highlight the diagnostic potential and relevance of glycan microheterogeneity and to present some novel methods for cancer detection. A computerized search of articles published up to 2007 was performed through the PubMed database. Search terms utilized included prostate/ovarian cancer glycosylation, prostate/ovarian cancer detection, PSA/CA125 glycosylation. Additional sources were identified through cross-referencing and researching in available biomedical books. The comparative studies of sugar chain structures of the PSA and CA125 indicated specific structural alterations associated with malignant transformation, in relation to glycan branching, sialylation and fucosylation. These glycan modifications should be better in distinguishing between benign and malignant conditions than the measurement of marker concentrations alone, which is widely used in practice. Cancer-associated changes in the glycosylation could yield more sensitive and discriminative diagnostic tests for reproductive tract cancer detection, i.e. for improvement of the clinical utility of known tumor markers or the discovery of new ones.

Pattern of serum immunoreactivity against breast cancer cell lysates may predict severity of disease in breast cancer patients

Humoral tumor-specific immunity has been investigated as a potential tool to identify tumor-associated antigens and evaluate cancer diagnosis and prognosis. Using SDS-PAGE and western blotting techniques we investigated the humoral immune response against tumor cell antigens in 36 breast cancer patients, 17 node-positive (NP) and 19 node-negative (NN). As a source of antigens, we prepared protein lysates from four breast cancer cell lines (AU565, BT474, MCF-7 and MDA-MB-231) which in vitro exhibit different features of invasion, estrogen receptor/progesterone receptor status and HER2/neu expression thereby potentially representing mild to aggressive forms of clinical disease. A higher number of immunocomplexes Ag-Ab were formed when serum from NN patients was immunoreacted against lysates from AU565 and MCF-7 in comparison to serum from NP patients (P < 0.01). BT474 cells were not a good antigenic source. MDA-MB-231 cells could not significantly discriminate between NN and NP patients since both groups showed higher amounts of reactivity against the lysate. However, comparative analysis of protein preparations purified from MCF-7 and MDA-MB-231 cells and immunodetected concomitantly with the same serum samples showed that serum from patients with cancers with worse prognosis (stage, nodality, HER2/neu and hormonal status) reacted more intensely to proteins purified from the relatively more invasive cell line MDA-MB-231 compared to MCF-7. These findings suggest that the study of serum antibody reactivity to antigens purified from breast cancer cell lines with different invasive properties should be further investigated for its potential in providing beneficial prognostic information in breast cancer.

Specific MALDI imaging and profiling for biomarker hunting and validation: fragment of the 11S proteasome activator complex, Reg alpha fragment, is a new potential ovary cancer biomarker

MALDI imaging mass spectrometry represents a new analytical tool to directly provide the spatial distribution and relative abundance of proteins in tissue. Twenty-five ovary carcinomas (stages III and IV) and 23 benign ovaries were directly analyzed using MALDI-TOF MS. The biomarker with the major prevalence (80%) has been fully identified using MALDI MS and nanoESI MS and MS/MS after separation by RP-HPLC and trypsin enzymatic digestion. This marker with an m/z of 9744 corresponds to 84 amino acid residues from the 11S proteasome activator complex, named PA28 or Reg-alpha. Validation of this marker has been performed using MALDI imaging, classical immunocytochemistry with an antibody raised against the C-terminal part of the protein, specific MALDI imaging, and Western blot analysis. The validation, using immunocytochemistry, confirmed the epithelial localization of this fragment with nucleus localization in benign epithelial cells and a cytoplasmic localization in carcinoma cells. This indicates that this antibody could be used to discriminate the borderline tumor cases. At this point, a multicentric study needs to be conducted in order to clearly establish the potential of this biomarker. Taken together these studies reflect that direct tissue analysis and specific MALDI imaging strategies facilitate biomarker hunting and validation which can be named pathological proteomics.

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.

Expression level of Wilms tumor 1 (WT1) protein has limited prognostic value in epithelial ovarian cancer: from the Danish "MALOVA" ovarian cancer study

OBJECTIVES

To determine the WT1 expression level in tumor tissues from 774 women with an epithelial ovarian tumor. Secondly, to evaluate whether WT1 tissue expression levels correlate with clinico-pathological parameters and finally to investigate the prognostic value of WT1 expression levels in ovarian cancer (OC) patients.

METHODS

Using tissue array we analyzed the WT1 expression level in tissues from 186 women with Low Malignant Potential tumors (LMP) (160 stage I, 5 stage II and 21 stage III) and 560 OC patients (160 stage I, 60 stage II, 289 stage III and 51 stage IV).

RESULTS

Using 10% as cut-off level for WT1 overexpression an overall of 19% LMPs and 17% carcinomas, respectively, were found positive. For both, a higher proportion of positive tumors was found in the serous subtype compared to other histological subtypes (p<0.0001). Kaplan-Meier survival analysis stratified by FIGO stage performed on cases using a 10% cut-off showed a shorter disease specific survival in patients with a positive WT1 expression in the tumor tissue. In a Cox survival analysis including 559 stage I to IV OC prognostic factors included FIGO stage (II vs. I: HR=2.74, 95% CI: 1.42-5.29; III vs. II: HR=2.23, 95% CI: 1.49-3.36; IV vs. III: HR=1.75, 95% CI: 1.25-2.44), residual tumor after primary surgery (HR=2.82, 95% CI: 1.87-4.26), age at diagnosis (HR=1.02, 95% CI: 1.01-1.03), histological grade 3 of tumor versus grade 1 (grade 2 vs. grade 1: HR=1.31, 95% CI: 0.95-1.81; grade 3 vs. grade 1: HR=1.51, 95% CI: 1.08-2.09) and other histological tumor types vs. serous (mucinous vs. serous: HR=0.91, 95% CI: 0.53-1.56; endometrioid vs. serous: HR=1.02, 95% CI: 0.69-1.50; other histological types vs. serous: HR=1.40, 95% CI: 1.01-1.95). WT1 expression (HR=1.22, 95% CI: 0.94-1.59) had statistically no significant independent impact on survival.

CONCLUSION

In conclusion, based on our analyses we found that WT1 expression in clinical settings may be of limited prognostic value in Danish OC patients.

Proteomics in human cancer research

Proteomics is now widely employed in the study of cancer. Many laboratories are applying the rapidly emerging technologies to elucidate the underlying mechanisms associated with cancer development, progression, and severity in addition to developing drugs and identifying patients who will benefit most from molecular targeted compounds. Various proteomic approaches are now available for protein separation and identification, and for characterization of the function and structure of candidate proteins. In spite of significant challenges that still exist, proteomics has rapidly expanded to include the discovery of novel biomarkers for early detection, diagnosis and prognostication (clinical application), and for the identification of novel drug targets (pharmaceutical application). To achieve these goals, several innovative technologies including 2-D-difference gel electrophoresis, SELDI, multidimensional protein identification technology, isotope-coded affinity tag, solid-state and suspension protein array technologies, X-ray crystallography, NMR spectroscopy, and computational methods such as comparative and de novo structure prediction and molecular dynamics simulation have evolved, and are being used in different combinations. This review provides an overview of the field of proteomics and discusses the key proteomic technologies available to researchers. It also describes some of the important challenges and highlights the current pharmaceutical and clinical applications of proteomics in human cancer research.

Altered proteome profiles in maternal plasma in pregnancies with fetal growth restriction

Fetal growth restriction (FGR) affects 3–5% of pregnancies and is associated with increased perinatal morbidity and mortality. Currently, there is no reliable biochemical test to differentiate a pathological FGR from a nonpathological one. The objective of this study was to screen whole maternal plasma to identify differentially expressed relatively abundant proteins associated with FGR. We analyzed maternal plasma from FGR (n=28) and healthy (n=22) pregnancies using two-dimensional gel electrophoresis (2D-GE) followed by software image analysis. Three spots with molecular weight (Mr) 18 kDa corresponding to haptoglobin (hp) α2, as identified by LC-MS/MS and immunoblotting, showed differential expression patterns in FGR. The distribution of hp α2 variants in maternal plasma samples showed the hp α2 variant 1 was low in 72% of FGR, medium in 16%, whereas high in 12%. In comparison, hp α2 variant 1 was high in (41%) of controls, medium in 41%, and low in 18% of cases. Based on the software image analysis, the mean spot volume for hp α2 variant 1 was 0.12 (SD=0.18) for FGR compared to 0.26 (SD=0.19) for control (p=0.006). Given that hp turnover is indicative of its maturation process and is traceable in plasma by its dominant/suppressed variants, we propose that hp α2 is an important potential target for evaluation of its clinical and pathophysiological role and as a diagnostic biomarker in FGR.

Protein expression analysis ofChlamydia pneumoniae persistence by combined surface-enhanced laser desorption ionization time-of-flight mass spectrometry and two-dimensional polyacrylamide gel electrophoresis

The aim of this study was to examine the protein expression profiles of persistentChlamydia pneumoniae by two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Although 2D PAGE is still the method of choice for separating and detecting components of complex protein mixtures, it has several distinct disadvantages; i.e., being labor-intensive and having a bias toward proteins within the dynamic range of the gel condition. Hence, SELDI-TOF-MS technology was used to complement 2D PAGE.C. pneumoniae-infected HEp2 cells were treated with or without IFN-γ, and protein expression profiles were determined at 48 h postinfection (hpi). Unfractionated monolayers were also used for protein profiling by SELDI-TOF, using two different chip surface types: weak cation exchanger and hydrophobic surface. Under IFN-γ-induced persistence,C. pneumoniae expresses an altered protein expression profile. Twenty chlamydial proteins showed differential regulatory patterns by SELDI-TOF-MS, two of which, HSP-70 cofactor, and a hypothetical protein, were identified by 2D PAGE and mass spectrometry. Two additional proteins, phosphatidylserine decarboxylase and 30S ribosomal protein S17, were exclusively identified by SELDI TOF-MS analysis, as these were not present in sufficient quantity for detection by 2D PAGE. We propose that a combination of 2D-PAGE and SELDI-TOF-MS may complement the disadvantages of each technique alone and may provide a rapid and precise screening technique.

CA125 expression pattern, prognosis and correlation with serum CA125 in ovarian tumor patients. From The Danish "MALOVA" Ovarian Cancer Study

OBJECTIVES

To determine the CA125 tissue expression levels in borderline and invasive epithelial ovarian tumor tissues. Secondly, to evaluate whether CA125 tissue expression levels correlate with clinico-pathological parameters and serum CA125 levels and finally to investigate the prognostic value of tissue CA125 expression levels in ovarian cancer (OC) patients.

METHODS

We designed tissue arrays (TA) and analyzed the CA125 expression in tissues from 778 Danish women with an ovarian tumor. Furthermore, corresponding preoperative blood samples obtained before surgery were collected from 382 women with OC.

RESULTS

Significantly more CA125 expression positive tumors (no expression vs. expression) were found in the serous subtype compared to the percentage of positive tumors in mucinous, endometroid and other subtypes for patients both with borderline ovarian tumors and with OC (p<0.00001, p<0.00001). Similarly, a positive significant correlation was found between elevated serum CA125 levels and elevated levels of CA125 tissue expression (N=382 stage I-IV OC, Spearman rho=0.31, p<0.0001) (N=206 stage III OC, Spearman rho=0.30, p<0.0001). We found a significantly shorter survival for stage III/IV OC patients with no CA125 tissue expression compared to stage III/IV OC patients with positive CA125 tissue expression (p=0.0003).

CONCLUSION

Our finding that tissue CA125 expression was lacking in late stage primary OC tumor of Danish women with poor survival may be of value in selecting patients as eligible candidates for individually based treatments.

Reactive oxygen species regulate epidermal growth factor-induced vascular endothelial growth factor and hypoxia-inducible factor-1alpha expression through activation of AKT and P70S6K1 in human ovarian cancer cells

The epidermal growth factor (EGF) and EGF receptor (EGFR) family are often overexpressed in various human cancers including ovarian cancer. While it is generally believed that reactive oxygen species (ROS) are involved in the intracellular signaling events, the role of ROS in EGF-induced angiogenesis and carcinogenesis remains to be elucidated. The present study investigated the role of ROS in the regulation of AKT, p70S6K1, vascular endothelial growth factor (VEGF), and hypoxia-inducible factor 1 (HIF-1) in ovarian cancer cells. In this study, OVCAR-3 cells were treated with EGF and catalase, an H2O2 scavenger. EGF treatment increases H2O2 production, leading to activation of the AKT/p70S6K1 pathway, resulting in increased VEGF expression at the transcriptional level. The inhibition of H(2)O(2) production by catalase abolished EGF-induced AKT and p70S6K1 activation, and VEGF expression through HIF-1alpha expression. Forced expression of p70S6K1 and HIF-1alpha reversed catalase- and rapamycin-inhibited VEGF transcriptional activation. We also showed that rapamycin, p70S6K1 inhibitor and catalase overexpression inhibited tumor angiogenesis. This study demonstrates a novel mechanism of EGF-induced VEGF and HIF-1alpha expression through production of H2O2 and activation of AKT and p70S6K1 in human ovarian cancer cells. This study also indicates that p70S6K1 and H2O2 are important in tumor angiogenesis. The results of the study could have an important implication in ovarian cancer therapy.

Raised Serum Chondroitin Sulfate Epitope Level in Ovarian Epithelial Cancer

OBJECTIVE

To determine the value of serum chondroitin sulfate epitope WF6 and hyaluronan (HA) levels as a biomarker for early detection of ovarian epithelial cancer and other gynecological disorders.

METHOD

Serum WF6 CS epitope and HA were measured in 91 patients with ovarian epithelial cancer, 39 patients with non-cancer gynecological disorders and 30 healthy women. Serum chondroitin sulfate (CS) WF6 epitope was determined by a competitive immunoassay with the monoclonal antibodies WF6, which specifically recognizes an epitope in native CS chains. In addition, serum HA concentration was measured by an ELISA-based assay with a biotinylated affinity HA-binding proteins.

RESULTS

The serum concentration of CS (WF6) epitope was highly increased in epithelial types of ovarian cancer and at all stages of development (p < 0.005). Serum HA in ovarian cancer patients was significantly higher than normal controls (p < 0.05).

CONCLUSION

These results reflect changes in ECM metabolism in progressive ovarian cancer, which cause an increase in serum CS epitopes and HA. Therefore, serum CS epitopes may provide useful biomarkers for cancers and other disorders of the ovary. Measurement of serum HA provided complementary information, which may be useful as a discriminator between benign ovarian disorders and malignant ovarian diseases.

Multilectin Affinity Chromatography for Characterization of Multiple Glycoprotein Biomarker Candidates in Serum from Breast Cancer Patients

Background: Glycoproteins are often associated with cancer and are important in serum studies, for which glycosylation is a common posttranslational modification.

Methods: We used multilectin affinity chromatography (M-LAC) to isolate glycoproteins from the sera of breast cancer patients and controls. The proteins were identified by HPLC–tandem mass spectrometry (MS/MS) analysis of the corresponding tryptic digests. We used the FuncAssociate Gene Ontology program for association analysis of the identified proteins. Biomarker candidates in these groups were comparatively quantitated by use of peak area measurements, with inclusion of an internal standard. We analyzed data for concordance within the ontology association groups for vector of change with the development of breast cancer.

Results: Detection of the known low-concentration biomarker HER-2 (8–24 μg/L) enabled us to establish a dynamic range of 106, relative to the amount of albumin, for the depletion step. We then used ELISA to confirm this range. Proteins associated with lipid transport and metabolism, cell growth and maintenance, ion homeostasis, and protease inhibition were found to be differentially regulated in serum from women with breast cancer compared with serum from women without breast cancer.

Conclusions: M-LAC for isolation of the serum glycoproteome, coupled with liquid chromatography–MS/MS and the use of gene ontology associations, can be used to characterize large panels of candidate markers, which can then be evaluated in a particular patient population.

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.

The application of genomic and proteomic technologies in predictive, preventive and personalized medicine

The long asymptomatic period before the onset of chronic diseases offers good opportunities for disease prevention. Indeed, many chronic diseases may be preventable by avoiding those factors that trigger the disease process (primary prevention) or by use of therapy that modulates the disease process before the onset of clinical symptoms (secondary prevention). Accurate prediction is vital for disease prevention so that therapy can be given to those individuals who are most likely to develop the disease. The utility of predictive markers is dependent on three parameters, which must be carefully assessed: sensitivity, specificity and positive predictive value. Specificity is important if a biomarker is to be used to identify individuals either for counseling or for preventive therapy. However, a reciprocal relationship exists between sensitivity and specificity. Thus, successful biomarkers will be highly specific without sacrificing sensitivity. Unfortunately, biomarkers with ideal specificity and sensitivity are difficult to find for many diseases. One potential solution is to use the combinatorial power of a large number of biomarkers, each of which alone may not offer satisfactory specificity and sensitivity. Recent technological advances in genetics, genomics, proteomics, and bioinformatics offer a great opportunity for biomarker discovery. The newly identified biomarkers have the potential to bring increased accuracy in disease diagnosis and classification, as well as therapeutic monitoring. In this review, we will use type 1 diabetes (T1D) as an example, when appropriate, to discuss pertinent issues related to high throughput biomarker discovery.

Proteomics in clinical trials and practice: present uses and future promise

The study of clinical proteomics is a promising new field that has the potential to have many applications, including the identification of biomarkers and monitoring of disease, especially in the field of oncology. Expression proteomics evaluates the cellular production of proteins encoded by a particular gene and exploits the differential expression and post-translational modifications of proteins between healthy and diseased states. These biomarkers may be applied towards early diagnosis, prognosis, and prediction of response to therapy. Functional proteomics seeks to decipher protein-protein interactions and biochemical pathways involved in disease biology and targeted by newer molecular therapeutics. Advanced spectrometry technologies and new protein array formats have improved these analyses and are now being applied prospectively in clinical trials. Further advancement of proteomics technology could usher in an era of personalized molecular medicine, where diseases are diagnosed at earlier stages and where therapies are more effective because they are tailored to the protein expression of a patient's malignancy.

A distinct molecular profile associated with mucinous epithelial ovarian cancer

Mucinous epithelial ovarian cancers (MOC) are clinically and morphologically distinct from the other histological subtypes of ovarian cancer. To determine the genetic basis of MOC and to identify potential tumour markers, gene expression profiling of 49 primary ovarian cancers of different histological subtypes was performed using a customised oligonucleotide microarray containing >59 000 probesets. The results show that MOC express a genetic profile that both differs and overlaps with other subtypes of epithelial ovarian cancer. Concordant with its histological phenotype, MOC express genes characteristic of mucinous carcinomas of varying epithelial origin, including intestinal carcinomas. Differences in gene expression between MOC and other histological subtypes of ovarian cancer were confirmed by RT–PCR and/or immunohistochemistry. In particular, galectin 4 (LGALS4) was highly and specifically expressed in MOC, but expressed at lower levels in benign mucinous cysts and borderline (atypical proliferative) tumours, supporting a malignant progression model of MOC. Hence LGALS4 may have application as an early and differential diagnostic marker of MOC.

Early diagnosis and predictors of malignancy of adnexal masses

PURPOSE OF REVIEW

Ovarian cancer is an important cause of death among women with a malignant gynecological tumor. Cure rates for the disease at an early stage are around 80-90%, but survival is only 50% as the majority of women already show advanced disease upon diagnosis. The combination of gynecological examination, ultrasonography, and systemic tumor marker assay is considered to be a good strategy for the early diagnosis of ovarian neoplasia.

RECENT FINDINGS

Today, new technologies such as ultrasonography and tumor marker assay have increased the diagnosis rate for adnexal masses. These non-invasive methods, however, frequently do not distinguish benign conditions from malignant ones, which results in unnecessary surgery. Transvaginal ultrasonography is useful for diagnosing adnexal masses, but benign and malignant adnexal masses can present similar morphological characteristics. Combination with color Doppler ultrasonography and/or tumor markers may improve the accuracy of the method. Gene-expression array, proteomics and mathematical models form new approaches, but proper prospective studies are needed to validate them.

SUMMARY

The techniques of pelvic examination, ultrasonography, color Doppler ultrasonography, and tumor markers can be indicated for the diagnosis of ovarian cancer. The differentiation between benign and malignant ovarian tumor is, however, a clinical challenge. Until better diagnostic methods become available, patients and their physicians can use these techniques to decide on management.

Clinical proteomics: from biomarker discovery and cell signaling profiles to individualized personal therapy

The discovery of new highly sensitive and specific biomarkers for early disease detection and risk stratification coupled with the development of personalized "designer" therapies holds the key to future treatment of complex diseases such as cancer. Mounting evidence confirms that the low molecular weight (LMW) range of the circulatory proteome contains a rich source of information that may be able to detect early stage disease and stratify risk. Current mass spectrometry (MS) platforms can generate a rapid and high resolution portrait of the LMW proteome. Emerging novel nanotechnology strategies to amplify and harvest these LMW biomarkers in vivo or ex vivo will greatly enhance our ability to discover and characterize molecules for early disease detection, subclassification and prognostic capability of current proteomics modalities. Ultimately genetic mutations giving rise to disease are played out and manifested on a protein level, involving derangements in protein function and information flow within diseased cells and the interconnected tissue microenvironment. Newly developed highly sensitive, specific and linearly dynamic reverse phase protein microarray systems are now able to generate circuit maps of information flow through phosphoprotein networks of pure populations of microdissected tumor cells obtained from patient biopsies. We postulate that this type of enabling technology will provide the foundation for the development of individualized combinatorial therapies of molecular inhibitors to target tumor-specific deranged pathways regulating key biologic processes including proliferation, differentiation, apoptosis, immunity and metastasis. Hence future therapies will be tailored to the specific deranged molecular circuitry of an individual patient's disease. The successful transition of these groundbreaking proteomic technologies from research tools to integrated clinical diagnostic platforms will require ongoing continued development, and optimization with rigorous standardization development and quality control procedures.

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.