Advances in ovarian cancer diagnosis: A journey from immunoassays to immunosensors

This review focuses on the technological advancements, challenges and trends in immunoassay technologies for ovarian cancer diagnosis. Emphasis is placed on the principles of the technologies, their merits and limitations and on the evolution from laboratory-based methods to point-of-care devices. While the current market is predominantly associated with clinical immunoassay kits, over the last decade a major thrust in development of immunosensors is evident due to their potential in point-of-care devices. Technological advancements in immunosensors, extending from labeled to label-free detection, with and without mediators, for enhancing proficiencies and reliability have been dealt with in detail. Aspects of the utilisation of nanomaterials and immobilization strategies for enhancing sensitivity and altering the detection range have also been addressed. Finally, we have discussed some distinct characteristics and limitations associated with the recently commericalised technologies used for quantitation of relevant ovarian cancer markers.     

Deciphering the ovarian cancer ascites fluid peptidome

Background

Conventional proteomic approaches have thus far been unable to identify novel serum biomarkers for ovarian cancer that are more sensitive and specific than the current clinically used marker, CA-125. Because endogenous peptides are smaller and may enter the circulation more easily than proteins, a focus on the low-molecular-weight region may reveal novel biomarkers with enhanced sensitivity and specificity. In this study, we deciphered the peptidome of ascites fluid from 3 ovarian cancer patients and 3 benign individuals (ascites fluid from patients with liver cirrhosis).

Results

Following ultrafiltration of the ascites fluids to remove larger proteins, each filtrate was subjected to solid phase extraction and fractionated using strong cation exchange chromatography. The resultant fractions were analyzed using an Orbitrap mass spectrometer. We identified over 2000 unique endogenous peptides derived from 259 proteins. We then catalogued over 777 peptides that were found only in ovarian cancer ascites. Our list of peptides found in ovarian cancer specimens includes fragments derived from the proteins vitronectin, transketolase and haptoglobin.

Conclusions

Peptidomics may uncover previously undiscovered disease-specific endogenous peptides that warrant further investigation as biomarkers for ovarian cancer.     

Copper content in ascitic fluid is associated with angiogenesis and progression in ovarian cancer

BackgroundAscites is associated with the poor prognosis of malignant tumors. The biological importance of the changes in the content of trace elements in the ascitic fluid is unknown. Herein, we analyzed trace elements in the ascitic fluid of patients with ovarian tumors and used cultured cells to determine the copper (Cu)-induced changes in gene expression in ovarian cancer.MethodsInductively coupled plasma mass spectrometry (ICP-MS) was used to compare ascitic fluid trace element levels in patients with benign ovarian tumors (n = 22) and borderline/malignant tumors (n = 5) for primary screening. Cu levels were validated using atomic absorption spectrometry (AAS) in 88 benign, 11 borderline, and 25 malignant ovarian tumor patients. To confirm Cu-induced gene expression changes, microarray analysis was performed for Cu-treated OVCAR3, A2780, and Met5A cells. The vascular endothelial growth factor (VEGF) concentration in the cell supernatant or ascitic fluid (ovarian cancer samples) was measured using ELISA.ResultsICP-MS showed that Co, Ni, Cu, Zn, As, Se, and Mo levels significantly increased in patients with malignant/borderline ovarian tumors compared to those in patients with benign ovarian tumors. AAS showed that malignant ovarian tumors were independently associated with elevated levels of Cu in ascites adjusted for age, body mass index, alcohol, smoking, and supplement use (p < 0.001). Microarray analysis of both Cu-treated ovarian cancer cell lines OVCAR3 and A2780 and the mesothelial cell line Met-5A revealed the upregulation of the angiogenesis biological process. Real-time polymerase chain reaction and ELISA demonstrated that an increased Cu content significantly enhanced VEGF mRNA expression and protein secretion in OVCAR3, A2780, and Met-5A cells. VEGF levels and clinical stages of the tumors correlated with the ascitic fluid Cu content in patients with malignant ovarian tumors (correlation coefficient 0.445, 95 % confidence interval [CI]: 0.069–0.710, p = 0.023 and correlation coefficient 0.406, 95 % CI: 0.022–0.686, p = 0.040, respectively).ConclusionCu levels significantly increased in patients with malignant ovarian cancer. Cu induced angiogenic effects in ovarian cancer and mesothelial cells, which affected ascites fluid production. This study clarifies the link between elevated Cu in ascites and malignant ovarian tumor progression. Strategies to decrease Cu levels in the ascitic fluid may help downregulate VEGF expression, thereby improving the prognosis of ovarian malignancies.     

Whole abdominal radiotherapy in ovarian cancer

Objectives

The aim of the study was to evaluate the clinical outcome and toxicity after adjuvant whole abdominal radiotherapy (WART) in patients with ovarian cancer.

Material and methods

Ten patients with optimal cytoreduced ovarian cancer, with a mean age of 58 years (40–70) and stage Ic: 4, stage II: 2, stage III: 4, were treated with WART and adjuvant chemotherapy (9/10). The total radiation dose was 22.5 Gy in the whole abdomen and 42–45 Gy in the pelvis.

Results

The mean follow-up was 8 years. The 5-year actuarial disease-free survival (DFS) was 60%, and the overall survival (OS) was 70%. Four patients had disease recurrence. The sites of recurrence were the abdomen in 2 patients and distant metastases in the other 2 patients (liver and brain metastasis). Gastrointestinal toxicity was as follows: acute 3/10 grades I and II, and late toxicity: 2/10 grades I and II, and only 1 patient developed small bowel obstruction (SBO) that required surgery.

Conclusions

Whole abdominal radiotherapy after surgery and platinum-based chemotherapy achieves high locoregional disease control with an acceptable risk of acute toxicity.     

Proteomics advances for precision therapy in ovarian cancer

ABSTRACT

Introduction: Due to the relatively low mutation rate and high frequency of copy number variation, finding actionable genetic drivers of high-grade serous carcinoma (HGSC) is a challenging task. Furthermore, emerging studies show that genetic alterations are frequently poorly represented at the protein level adding a layer of complexity. With improvements in large-scale proteomic technologies, proteomics studies have the potential to provide robust analysis of the pathways driving high HGSC behavior.

Areas covered: This review summarizes recent large-scale proteomics findings across adequately sized ovarian cancer sample sets. Key words combined with ‘ovarian cancer’ including ‘proteomics’, ‘proteogenomic’, ‘reverse-phase protein array’, ‘mass spectrometry’, and ‘adaptive response’, were used to search PubMed.

Expert opinion: Proteomics analysis of HGSC as well as their adaptive responses to therapy can uncover new therapeutic liabilities, which can reduce the emergence of drug resistance and potentially improve patient outcomes. There is a pressing need to better understand how the genomic and epigenomic heterogeneity intrinsic to ovarian cancer is reflected at the protein level and how this information could be used to improve patient outcomes.     

Nelfinavir induces TRAIL receptor upregulation in ovarian cancer cells

HIV protease inhibitors are currently being discussed to be useful as new and alternative anti-cancer agents, especially as second line treatments for chemo-resistant human cancer types. Among three clinically applied HIV protease inhibitors tested, we found a high efficacy of nelfinavir on ovarian cancer cells, accompanied by apoptosis (annexin binding) and necrosis (propidium iodide permeability). In vitro, at concentrations used to induce cell death in ovarian cancer cells, nelfinavir had no effect on the cellular viability of fibroblasts or peripheral blood mononuclear leukocytes. Nelfinavir sensitized ovarian cancer cells to treatment with an apoptosis-inducing TRAIL receptor antibody due to upregulation of the TRAIL receptor DR5 as shown by RT-PCR and FACScan analysis. We conclude that nelfinavir, an already approved drug, is a highly efficient agent against ovarian cancer cells and could sensitize ovarian cancer cells to TRAIL treatment, either therapeutically applied or endogenously produced by cells of the immune system.     

卵巢癌患者术后阴道微生态分析

目的 对卵巢癌患者术后阴道微生态特征进行回顾性分析,为临床预防及诊疗提供参考.方法 选取158例卵巢癌术后患者为卵巢癌组,150例同期健康体检者为对照组,对留取样本进行革兰染色镜检及阴道五项联检检测,并对阴道微生态结果进行统计分析.结果 卵巢癌组阴道五联检各指标异常率高于对照组(均P＜0.05).革兰染色油镜镜检联合五...     

Proteomic search for potential diagnostic markers and therapeutic targets for ovarian clear cell adenocarcinoma

Clear cell adenocarcinoma (CCA) has a highly malignant potential in human epithelial ovarian cancer. The serum CA-125 is widely used as a marker for ovarian cancer, but the level is relatively low in CCA. Therefore, new sensitive biomarkers are required. In this report, we describe a promising proteomic analysis that is differentially expressed in CCA when compared to mucinous adenocarcinoma, using the ovarian cultured cell lines OVISE, OVTOKO, and MCAS. The disease-associated proteins were identified by 2-D differential gel electrophoresis (2-D DIGE) and MS. In this analysis, 18 up-regulated and 31 down-regulated spots were observed that had at least two-fold differences in the two CCA cell lines than in MCAS as control cells. Some of the proteins differentially expressed in CCA were previously observed as alternative expression levels in ovarian and/or other cancers in clinical samples. In a subsequent preliminary differential study using surgical specimens from patients with CCA, it was demonstrated that the identified proteins were expressed differentially in actual tissues, as well as in the CCA culture cells. The results from this investigation show the potentiality of a proteomic approach for identifying disease-associated proteins, which may eventually serve as diagnostic markers or therapeutic targets in CCA.     

Phototoxicity of Hemoporfin to ovarian cancer

Hematoporphyrin monomethyl ether (Hemoporfin) is a novel porphyrin-related photosensitizer. Photocytotoxic effect of Hemoporfin to ovarian cancer is still unclear. We used human epithelial ovarian carcinoma cell line SKOV3 and its xenograft model in nude mice to investigate the Hemoporfin-based photodynamic therapy (PDT) for ovarian cancer. The growth rates of SKOV3 cells were determined by MTT assays. Flow cytometry combined with dual Annexin V/PI staining was used to identify the death mode of the cells following PDT. We demonstrated that Hemoprofin-based PDT induced significant cell death via direct necrosis induction, and the photocytotoxity to SKOV3 cells is dose related. With SKOV3 xenograft model in nude mouse, we further demonstrated that Hemoporfin-based PDT is effective for controlling the tumor growth. Our results suggest that Hemoporfin is a promising novel photosensitizer for the treatment of ovarian cancer and merit further evaluation in the clinical practice.     

Engineering of lipid microbubbles-coated copper and selenium nanoparticles: Ultrasound-stimulated radiation of anticancer activity ian human ovarian cancer cells

In this study, we have designed developed the microbubbles (MBs) coated Cu-Se nanoparticles (MBs@Cu-Se NPs) was efficiently synthesized and combined with the Ultrasound for potential anticancer effects in ovarian carcinoma cells. The fabricated nanoparticles are perceived as the well-known spherical size by SEM and TEM analysis. The hydrodynamic parameters of the MBs@Cu-Se NPs confirm via DLA analysis. Further, in vitro cancer potential of the Cu-Se, MBs@Cu-Se NPs and MBs@Cu-Se NPs with Ultrasound efficiently kills the ovarian cancer cells (A2780 and CisRA2780) and reduced the cell viability in a dose-dependent manner. The MBs@Cu-Se NPs with Ultrasound displayed remarkably higher amounts of apoptosis of the ovarian cancers, which was confirmed by the various biochemical assays (AO-EB), and Hoechst-33,258 by nuclear staining. Additionally, we examined the apoptosis mechanism through the flow cytometry technique. The results reveal that the MBs@Cu-Se NPs with Ultrasound significantly induce apoptosis in both cancer cells. These results suggest that the in vitro cytotoxicity potential of MBs@Cu-Se NPs with Ultrasound combination therapy against ovarian carcinoma. Overall, new approaches of combination therapy of MBs@Cu-Se NPs with Ultrasound could be a promising alternative strategy and efficient chemotherapy as well as radiotherapy.     

Characterization of serum biomarkers for detection of early stage ovarian cancer

We have previously reported the identification of three ovarian cancer biomarker panels comprised of SELDI-TOF-MS peaks representing 14 differentially expressed serum proteins for the diagnosis of ovarian cancer. Using micro-LC-MS/MS, we identified five m/z peaks as transthyretin (TTR 13.9 kDa, TTR fragment 12.9 kDa), beta-hemoglobin (Hb, 15.9 kDa), apolipoprotein AI (ApoAI, 28 kDa) and transferrin (TF, 79 kDa). Western and/or ELISA methods confirmed the differential expression of TTR, Hb, and TF, and multivariate analyses resulted in improving the detection of early stage ovarian tumors (low malignant potential and malignant; receiver operating characteristic, ROC 0.933) as compared to cancer antigen CA125 alone (ROC 0.833). Interestingly, when CA125 was included with our markers in the multivariate analysis, the ROC increased to 0.959. Furthermore, multivariate analysis with only the mucinous subtype of early stage ovarian tumors, showed our markers to greatly improve the detection of disease (ROC 0.959) as compared to CA125 alone (ROC 0.613). Interestingly, the combination of CA125 with our markers did not seem to further improve the detection of mucinous tumors (ROC 0.955). We conclude that TTR, Hb, ApoAI and TF, when combined with CA125 should significantly improve the detection of early stage ovarian cancer.     

Genetic polymorphisms in AURKA,BRCA1, CCNE1 and CDK2 are associated with ovarian cancer susceptibility among Chinese Han women

IntroductionCentrosome aberrations and cell-cycle deregulation have important implications for ovarian cancer development. The AURKA, BRCA1, CCNE1 and CDK2 genes play pivotal roles in centrosome duplication and cell-cycle regulation.MethodsUsing a haplotype-based analysis, this study aimed to investigate whether genetic polymorphisms in these four genes may contribute to ovarian cancer susceptibility. A total of 22 single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 287 cases of ovarian serous cystadenocarcinomas and 618 age-matched cancer-free controls from the Chinese Han population, and then haplotype blocks were reconstructed according to our genotyping data and linkage disequilibrium (LD) status of these SNPs.ResultsFor AURKA, we found that haplotype GA [rs6064391 (T→G) + rs911162 (G→A)] was strongly associated with decreased ovarian cancer risk (adjusted OR = 0.31, 95% CI = 0.15–0.63, P = 0.0012). For BRCA1, we found that haplotype CGTAG was associated with decreased ovarian cancer risk (adjusted OR = 0.64, 95% CI = 0.41–0.98, P = 0.0417). Moreover, women harboring homozygous GA/CGTAG haplotypes showed the lowest risk (OR = 0.12, 95% CI = 0.02–0.94, P = 0.0438). In CCNE1, the SNPs rs3218035 and rs3218042 were significantly associated with increased ovarian cancer risk (rs3218035: adjusted OR = 5.20, 95% CI = 1.85–14.52, P = 0.0017; rs3218042: adjusted OR = 4.98, 95% CI = 1.75–14.19, P = 0.0027). For CDK2, no significant association was found.ConclusionsThis study indicates that genetic polymorphisms of AURKA, BRCA1 and CCNE1 may affect ovarian cancer susceptibility in Chinese Han women.     

Modulation of inflammatory signaling pathways by phytochemicals in ovarian cancer

Inflammation has been suggested to be involved in cancer development and progression. Many clinical and experimental studies have shown that inflammation could contribute to ovarian carcinogenesis through activation of the NF-κB and AP-1 pathways by chronic inflammatory mediators. Phytochemicals, which are natural compounds derived from fruits and vegetables, have shown anti-inflammatory and anti-cancer effects. Due to their relatively low toxicity and easy accessibility, phytochemicals have been investigated for their chemopreventive potential against various cancers. In this review, we discuss the role of phytochemicals in preventing ovarian cancer through anti-inflammatory mechanisms.     

The ovarian cancer-derived secretory/releasing proteome: A repertoire of tumor markers

Ovarian cancer is the most lethal gynecological malignancy worldwide, and early detection of this disease using serum or plasma biomarkers may improve its clinical outcome. In the present study, a large scale protein database derived from ovarian cancer was created to enable tumor marker discovery. First, primary organ cultures were established with the tumor tissues and corresponding normal tissues obtained from six ovarian cancer patients, and the serum-free conditioned medium (CM) samples were collected for proteomic analysis. The total proteins from the CM sample were separated by SDS-PAGE, digested with trypsin and then analyzed by LC-MS/MS. Combining data from the tumor tissues and the normal tissues, 1129 proteins were identified in total, of which those categorized as "extracellular proteins" and "plasma membrane proteins" accounted for 21.4% and 16.9%, respectively. For validation, three secretory proteins (NID1, TIMP2, and VCAN) involved in "organ development"-associated subnetwork, showed significant differences between their levels in the circulating plasma samples from ovarian cancer patients and healthy women. In conclusion, this ovarian cancer-derived protein database provides a credible repertoire of potential biomarkers in blood for this malignant disease, and deserves mining further.     

Modulation of Janus kinase 2 by p53 in ovarian cancer cells

The constitutive activation of the Janus kinase 2 (JAK2) and mutation of the p53 tumor suppressor are both detected in human cancer. We examined the potential regulation of JAK2 phosphorylation by wild-type (wt) p53 in human ovarian cancer cell lines, Caov-3 and MDAH2774, which harbor mutant form of p53 tumor suppressor gene and high levels of phosphorylated JAK2. The wt p53 gene was re-introduced into the cells using an adenovirus vector. In addition to wt p53, mutant p53 22/23, mutant p53-175, and NCV (negative control virus) were introduced into the cells in the control groups. Expression of wt p53, but not that of p53-175 mutant, diminished JAK2 tyrosine phosphorylation in MDAH2774 and Caov-3 cell lines. Expression of wt p53 or p53 22/23 mutant did not cause a reduction in the phosphorylation of unrelated protein kinases, ERK1 and ERK2 (ERK1/2). The inhibition of JAK2 tyrosine phosphorylation can be reversed by tyrosine phosphatase inhibitor, sodium orthovanadate. Protein tyrosine phosphatase 1-B levels increased with introduction of wt p53 and may be involved in the dephosphorylation of JAK2. These findings present a possible p53-dependent cellular process of modulating JAK2 tyrosine phosphorylation in ovarian cancer cell lines.     

Progesterone receptor (PROGINS) polymorphism and the risk of ovarian cancer

The present case–control study evaluates the role of the progesterone receptor (PR) polymorphism known as PROGINS as a risk factor for ovarian cancer development and investigates the association between these genetic variants and clinical/pathologic variables of ovarian cancer. PROGINS polymorphism was examined, by polymerase chain reaction, in a total of 80 patients with ovarian cancer and 282 control subjects. The frequencies of PROGINS polymorphism T1/T1, T1/T2, and T2/T2 were 71.3, 15.0 and 13.8% in ovarian cancer patients and 78.37, 21.63 and 0% in controls, respectively. The χ²-test showed a higher incidence of the T2/T2 genotype (P = 0.001) in the ovarian cancer group. In addition, women carrying a mutated allele (T2) showed approximately 2.2 times higher risk of ovarian cancer development as compared to women who have a variant allele (odds ratio (OR) = 2.2; 95% CI = 1.80–3.54). Regarding the clinical and pathologic findings observed within the cancer group, there was a significant correlation between PROGINS polymorphism and patients with a familial history (χ² = 6.776; P = 0.009; Fischer exact test, P = 0.01). In this regard, patients with familial antecedents have a 4.7 times higher likelihood to have at least one risk allele (T2) as compared with patients without familial antecedents (OR = 4.69; 95% CI = 1.38–15.87). No correlations were observed among the other variables. These data suggest that the PROGINS polymorphism T2/T2 genotype might be associated with an increased risk of ovarian cancer.     

Proteomics and ovarian cancer: Integrating proteomics information into clinical care

The power of proteomics allows unparalleled opportunity to query the molecular mechanisms of a malignant cell and the tumor microenvironment in patients with ovarian cancer and other solid tumors. This information has given us insight into the perturbations of signaling pathways within tumor cells and has aided the discovery of new drug targets for the tumor and possible prognostic indicators of outcome and disease response to therapy. Proteomics analysis of serum and ascites has also given us sources with which to discover possible early markers for the presence of new disease and for the progression of established cancer throughout the course of treatment. Unfortunately, this wealth of information has yielded little to date in changing the clinical care of these patients from a diagnostic, prognostic, or treatment perspective. The rational examination and translation of proteomics data in the context of past clinical trials and the design of future clinical trials must occur before we can march forward into the future of personalized medicine.     

Loss of ovarian function and the risk of ovarian cancer

Animal models with premature ovarian failure resulting from the loss or depletion of germ cells consistently develop ovarian surface epithelial cell hyperplasia with invasion into the stroma and the development of ovarian tubular adenomas. In human ovaries, deep epithelial invaginations and inclusion cysts occur at increasing frequency with age and are thought to be the structures from which the majority of ovarian cancers arise. A feature that is common to these animal models and to post-menopausal women is a deficiency in the number of oocytes. The potential consequences of the loss or depletion of female germ cells, naturally or otherwise, include failure of follicle development, significant reductions in oestrogen and progesterone levels and elevation of circulating levels of gonadotropins. This review will consider the way in which these structural and hormonal changes affect ovarian cancer risk. Some lessons may be learned from gonad formation, since notable similarities exist between ovarian tumorigenesis and embryonic gonadogenesis including fragmentation of the basement membrane underlying the coelomic (surface) epithelium, the potential for the migration of epithelial cells into the gonad and the importance of the germ cells for the regulation of ovarian structure and function. Research was supported by grants from the National Cancer Institute of Canada and the Canadian Institutes of Health Research.