Proteomic analysis for early detection of ovarian cancer: a realistic approach?

Proteomic Strategies and their Application in Cancer Research

The understanding of carcinogenesis and tumor progression on a molecular basis needs a detailed study of proteins as effector molecules and as critical components of the multiple interconnected signaling pathways that drive the neoplastic phenotype. Thus, the proteomic approach represents a powerful tool for the challenge of the post-genomic era. The term “cancer proteome” refers to the collection of proteins expressed by a given cancer cell and should be considered as a highly dynamic entity within the cell, which affects a variety of cellular activities. The emerging proteomic analysis platforms including 2D-PAGE, mass spectrometry technologies, and protein microarrays represent powerful tools to study and understand cancer. These systems aim to not only identify, catalogue, and characterize cancer proteins, but also to unveil how they interact to affect overall tumor progression. Moreover, recent studies on various cancers have reported promising results concerning the detection of novel molecular biomarkers useful in the early diagnosis of cancer and in drug discovery. Thus, a new subdiscipline named clinical proteomics, concomitant with new molecular technologies that are developed, demonstrates promise to discover new cancer biomarkers. The early diagnosis of cancer, even in a premalignant state, is crucial for the successful treatment of this disease. For these reasons, it is clear that the identification of biomarkers for the early diagnosis of cancer should represent one of the main goals of this emerging field of study.

Multiplex Immunosensor Arrays for Electrochemical Detection of Cancer Biomarker Proteins

Measuring panels of protein biomarkers offer a new personalized approach to early cancer detection, disease monitoring and patients' response to therapy. Multiplex electrochemical methods are uniquely positioned to provide faster, more sensitive, point of care (POC) devices to detect protein biomarkers for clinical diagnosis. Nanomaterials-based electrochemical methods offer sensitivity needed for early cancer detection. This review discusses recent advances in multiplex electrochemical immunosensors for cancer diagnostics and disease monitoring. Different electrochemical strategies including enzyme-based immunoarrays, nanoparticle-based immunoarrays and electrochemiluminescence methods are discussed. Many of these methods have been integrated into microfluidic systems, but measurement of more than 2-4 protein markers in a small single serum sample is still a challenge. For POC applications, a simple, low cost method is required. Major challenges in multiplexed microfluidic immunoassays are reagent additions and washing steps that require creative engineering solutions. 3-D printed microfluidics and paper-based microfluidic devices are also explored.

Design of luciferase-displaying protein nanoparticles for use as highly sensitive immunoassay detection probes

In this study, we developed a protein nanoparticle-based immunoassay to detect cancer biomarkers using a bioluminescent fusion protein.

High throughput immunosenor based on multi-label strategy and a novel array electrode

Accurate prediction of a particular cancer can be achieved by measuring multiplex biomarkers. Traditional methods for multi-biomarkers detection are either multi-spots assay with chip or multi-label assay with one detection spot. However, the detection throughput of these two approaches is limited by the substrate area and the numbers of available label respectively. To solve this problem, in the present study, an immunoassay was firstly prepared by combining multi-label strategy and multi-spot assay with a novel array electrode for simultaneous detection of six biomarkers for hepatocellular carcinoma (HCC). The detection throughput of the proposed method was doubled in comparison with traditional multi-spots assay (one target protein was detected on each analytic spot), which could greatly enhance the sensitivity and specificity of HCC diagnosis. This detection model may serve as the starting point for high throughput of multianalyte assay.

Sensitive detection of protein and miRNA cancer biomarkers using silicon-based photonic crystals and a resonance coupling laser scanning platform

Enhancement of the fluorescent output of surface-based fluorescence assays by performing them upon nanostructured photonic crystal (PC) surfaces has been demonstrated to increase signal intensities by >8000×. Using the multiplicative effects of optical resonant coupling to the PC in increasing the electric field intensity experienced by fluorescent labels ("enhanced excitation") and the spatially biased funneling of fluorophore emissions through coupling to PC resonances ("enhanced extraction"), PC enhanced fluorescence (PCEF) can be adapted to reduce the limits of detection of disease biomarker assays, and to reduce the size and cost of high sensitivity detection instrumentation. In this work, we demonstrate the first silicon-based PCEF detection platform for multiplexed biomarker assay. The sensor in this platform is a silicon-based PC structure, comprised of a SiO2 grating that is overcoated with a thin film of high refractive index TiO2 and is produced in a semiconductor foundry for low cost, uniform, and reproducible manufacturing. The compact detection instrument that completes this platform was designed to efficiently couple fluorescence excitation from a semiconductor laser to the resonant optical modes of the PC, resulting in elevated electric field strength that is highly concentrated within the region <100 nm from the PC surface. This instrument utilizes a cylindrically focused line to scan a microarray in <1 min. To demonstrate the capabilities of this sensor-detector platform, microspot fluorescent sandwich immunoassays using secondary antibodies labeled with Cy5 for two cancer biomarkers (TNF-α and IL-3) were performed. Biomarkers were detected at concentrations as low as 0.1 pM. In a fluorescent microarray for detection of a breast cancer miRNA biomarker miR-21, the miRNA was detectable at a concentration of 0.6 pM.

Elastomeric negative acoustic contrast particles for affinity capture assays

This report describes the development of elastomeric capture microparticles (ECμPs) and their use with acoustophoretic separation to perform microparticle assays via flow cytometry.We have developed simple methods to form ECμPs by cross-linking droplets of common commercially available silicone precursors in suspension followed by surface functionalization with biomolecular recognition reagents. The ECμPs are compressible particles that exhibit negative acoustic contrast in ultrasound when suspended in aqueous media, blood serum, or diluted blood. In this study, these particles have been functionalized with antibodies to bind prostate specific antigen and immunoglobulin (IgG). Specific separation of the ECμPs from blood cells is achieved by flowing them through a microfluidic acoustophoretic device that uses an ultrasonic standing wave to align the blood cells, which exhibit positive acoustic contrast, at a node in the acoustic pressure distribution while aligning the negative acoustic contrast ECμPs at the antinodes. Laminar flow of the separated particles to downstream collection ports allows for collection of the separated negative contrast (ECμPs) and positive contrast particles (cells). Separated ECμPs were analyzed via flow cytometry to demonstrate nanomolar detection for prostate specific antigen in aqueous buffer and picomolar detection for IgG in plasma and diluted blood samples. This approach has potential applications in the development of rapid assays that detect the presence of low concentrations of biomarkers in a number of biological sample types.

GOLD NANOPARTICLES-BASED BIOSENSORS FOR BIOMEDICAL APPLICATION

Gold nanoparticles are the most extensively studied nanomaterials for biomedical application due to their unique properties, such as rapid and simple synthesis, large surface area, strong adsorption ability and facile conjugation to various biomolecules. The remarkable photophysical properties of gold nanoparticles have provided plenty of opportunities for the preparation of gold nanoparticles-based optical biosensors, while the excellent biocompatibility, conductivity, catalytic properties and large surface-to-volume ratio have facilitated the application of gold nanoparticles in the construction of electrochemical biosensors. In this review, we mainly detail the gold nanoparticles-based optical and electrochemical biosensors for biomedical application in the recent two years, which have exhibited greatly enhanced analytical performances in the detection of DNA, proteins and some important small molecules.

Measurement of biomarker proteins for point-of-care early detection and monitoring of cancer

This critical review evaluates progress toward viable point-of-care protein biomarker measurements for cancer detection and diagnostics. The ability to measure panels of specific, selective cancer biomarker proteins in physicians' surgeries and clinics has the potential to revolutionize cancer detection, monitoring, and therapy. The dream envisions reliable, cheap, automated, technically undemanding devices that can analyze a patient's serum or saliva in a clinical setting, allowing on-the-spot diagnosis. Existing commercial products for protein assays are reliable in laboratory settings, but have limitations for point-of-care applications. A number of ultrasensitive immunosensors and some arrays have been developed, many based on nanotechnology. Multilabel detection coupled with high capture molecule density in immunosensors and arrays seems to be capable of detecting a wide range of protein concentrations with sensitivity ranging into the sub pg mL(-1) level. Multilabel arrays can be designed to detect both high and ultralow abundance proteins in the same sample. However, only a few of the newer ultrasensitive methods have been evaluated with real patient samples, which is key to establishing clinical sensitivity and selectivity.

Ultrasensitive electrochemical immunosensor for oral cancer biomarker IL-6 using carbon nanotube forest electrodes and multilabel amplification

Squamous cell carcinomas of head and neck (HNSCC) are associated with immune, inflammatory, and angiogenic responses involving interleukin-6 (IL-6). This article reports an ultrasensitive electrochemical immunosensor for human IL-6 and proof-of-concept studies of IL-6 detection in HNSCC cells. Single wall carbon nanotube (SWNT) forests with attached capture antibodies (Ab(1)) for IL-6 were used in an electrochemical sandwich immunoassay protocol using enzyme label horseradish peroxidase (HRP) to measure very low ( Collapse

Key Words Collapse

MESH Headings

• Biomarkers, Tumor/analysis
• Biosensing Techniques
• Carcinoma, Squamous Cell/diagnosis
• Cell Line, Tumor
• Electrodes
• Enzyme-Linked Immunosorbent Assay
• Head and Neck Neoplasms/diagnosis
• Humans
• Immunoenzyme Techniques/methods
• Interleukin-6/analysis
• Nanotubes, Carbon/chemistry
• Staining and Labeling

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Grants

• R01 ES013557 NIEHS NIH HHS
• R01 ES013557-04 NIEHS NIH HHS
• Intramural NIH HHS
• ES013557 NIEHS NIH HHS

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Affiliation(s)

Ruchika Malhotra Department of Chemistry and Institute of Materials Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, USA
Vyomesh Patel
Jose Pedro Vaqué
J Silvio Gutkind
James F Rusling

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Proteomic profiling in ovarian cancer

OBJECTIVE

To describe the role of proteomic profiling in the diagnosis and treatment of ovarian cancer.

METHODS

We report a thorough review of the literature, ongoing trials, and our group's experience with proteomic profiling for early detection, recurrence, and treatment of ovarian cancer.

RESULTS/CONCLUSIONS

Ovarian cancer remains the deadliest gynecologic malignancy in the western world and is most often diagnosed at a rarely curable late stage. Novel applications of proteomic techniques, such as mass spectrometry, show promise in the quest for reliable multimodality screening programs for the early detection of ovarian cancer. Proteomic analysis of tissue samples has underscored the heterogeneity of this disease process. Development of validated assays that survey the genetic and/or proteomic makeup of an individual tumor will add greatly to the histological classification of the tumor and may lead to different treatment approaches tailored to the unique expression pattern of each individual patient. As novel agents that disrupt signal propagation develop, proteomic profiling by reverse-phase protein arrays can characterize the in-tumor efficacy of the agent by quantification of the changes in expression levels of activated proteins. Together, better understanding of the potential diagnostic and therapeutic targets followed with proof-of-target effect will lead to rational combinations of novel therapy and improve individual ovarian cancer patient outcome.

The power of the web in cancer drug discovery and clinical trial design: research without a laboratory?

The discovery of effective cancer treatments is a key goal for pharmaceutical companies. However, the current costs of bringing a cancer drug to the market in the USA is now estimated at $1 billion per FDA approved drug, with many months of research at the bench and costly clinical trials. A growing number of papers highlight the use of data mining tools to determine associations between drugs, genes or protein targets, and possible mechanism of actions or therapeutic efficacy which could be harnessed to provide information that can refine or direct new clinical cancer studies and lower costs. This report reviews the paper by R.J. Epstein, which illustrates the potential of text mining using Boolean parameters in cancer drug discovery, and other studies which use alternative data mining approaches to aid cancer research.

Designing nanomaterial-enhanced electrochemical immunosensors for cancer biomarker proteins

Detection of multiple cancer biomarker proteins in human serum and tissue at point-of-care is a viable approach for early cancer detection, but presents a major challenge to bioanalytical device development. This article reviews recent approaches developed in our laboratories combining nanoparticle decorated electrodes and multilabeled secondary antibody labeled particles to achieve high sensitivity for the detection of cancer biomarker proteins. Two nanomaterial-based sensor platforms were used: (a) upright single wall carbon nanotube forests and (b) layers of densely packed 5 nm gold nanoparticles. Both platforms feature pendant carboxylate groups for easy attachment of enzymes or antibodies by amidization. In quality performance tests, the biocatalytic responses for determination of hydrogen peroxide of AuNP layers with attached horseradish peroxidase (HRP) on electrodes gave somewhat better detection limit and sensitivity than single wall carbon nanotube (SWNT) forest platforms with HRP attached. Evaluation of these sensors as platforms for sandwich immunoassays for cancer biomarker prostate specific antigen (PSA) in serum showed that both approaches gave accurate results for human serum samples from cancer patients. The best detection limit (0.5 pg mL(-1)) and sensitivity were obtained by combining the AuNP immunosensors with binding of 1 mum diameter magnetic particles decorated with secondary antibodies and 7500 HRP labels.

Ten years of “Optimal Therapy in Advanced Ovarian Cancer. Update” Meeting

TheInternational Symposium on Advanced Ovarian Cancer: Optimal Therapywas founded by Dr. Andrés Poveda and Prof. Jan B. Vermorken, and each edition has been directed by them. The 6th edition was held on March 2, 2007. This symposium is organized every other year by GEICO (Grupo Español de Investigación de Cáncer de Ovario/Spanish Ovarian Cancer Research Group), under the auspices of the Spanish Society of Medical Oncology (SEOM), the Gynecologic Cancer Intergroup (GCIG), and the European Society of Medical Oncology (ESMO) Educational Committee for its Medical Oncology Recertification Approval (ESMO/MORA) Program. One hundred and fifty people attended the symposium's 1st edition, held in 1996. Since then, the interest in this meeting has increased. Last year, almost three hundred people coming not only from Spain but also from Europe, North and Latin America, Asia, and Australia were present in the symposium. This is a great challenge for us. Some important international cooperative groups from Europe, America, and Australia collaborate with this symposium, such as GOG, NCIC, EORTC, AGO, Scottish Group, ICON, GINECO, NSGO, ANZGOG, and others.

Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

The unique electronic and optical properties of carbon nanotubes, in conjunction with their size and mechanically robust nature, make these nanomaterials crucial to the development of next-generation biosensing platforms. In this Review, we present recent innovations in carbon nanotube-assisted biosensing technologies, such as DNA-hybridization, protein-binding, antibody-antigen and aptamers. Following a brief introduction on the diameter- and chirality-derived electronic characteristics of single-walled carbon nanotubes, the discussion is focused on the two major schemes for electronic biodetection, namely biotransistor- and electrochemistry-based sensors. Key fabrication methodologies are contrasted in light of device operation and performance, along with strategies for amplifying the signal while minimizing nonspecific binding. This Review is concluded with a perspective on future optimization based on array integration as well as exercising a better control in nanotube structure and biomolecular integration.

Multiple biomarker panels for early detection of ovarian cancer

Ovarian cancer is the eighth most common cause of cancer mortality in women. It is diagnosed in more than 20,000 women in the USA each year and approximately 15,000 women die of the disease annually. The majority of patients are diagnosed with advanced-stage ovarian cancer, as this deadly disease causes minimal and nonspecific symptoms until late in the course of the disease. No standardized screening test exists to reliably detect ovarian cancer. Cancer antigen (CA)-125 is a protein antigen found at abnormally high levels in the blood of many women with ovarian cancer. Most healthy women have CA-125 levels of below 35 units/microl of blood serum. However, a number of noncancerous conditions can cause elevated CA 125 levels, and many women with early-stage ovarian cancer have normal CA-125 levels. Owing to these limitations, this test is not recommended for routine screening in women who are not at high risk or who do not have specific symptoms of the disease. Currently, many researchers are focusing on simultaneous examination of multiple markers to increase sensitivity of the screening test for early detection of ovarian cancer. Analysis of the current literature shows that combining several biomarkers dramatically improves sensitivity of CA-125 in ovarian cancer patients. This article provides a comprehensive overview of existing studies in the area of multimarker panel development for the early detection and monitoring of ovarian cancer. Our literature review demonstrates that a multimarker approach for the generation of a prototype assay for early detection of ovarian cancer has a great potential to lead to the development of a screening test for this disease.

Carbon nanotube amplification strategies for highly sensitive immunodetection of cancer biomarkers

We describe herein the combination of electrochemical immunosensors using single-wall carbon nanotube (SWNT) forest platforms with multi-label secondary antibody-nanotube bioconjugates for highly sensitive detection of a cancer biomarker in serum and tissue lysates. Greatly amplified sensitivity was attained by using bioconjugates featuring horseradish peroxidase (HRP) labels and secondary antibodies (Ab(2)) linked to carbon nanotubes (CNT) at high HRP/Ab(2) ratio. This approach provided a detection limit of 4 pg mL(-)(1) (100 amol mL(-)(1)), for prostate specific antigen (PSA) in 10 microL of undiluted calf serum, a mass detection limit of 40 fg. Accurate detection of PSA in human serum samples was demonstrated by comparison to standard ELISA assays. PSA was quantitatively measured in prostate tissue samples for which PSA could not be differentiated by the gold standard immunohistochemical staining method. These easily fabricated SWNT immunosensors show excellent promise for clinical screening of cancer biomarkers and point-of-care diagnostics.

Ovarian cancer: is the news good enough?

Ovarian cancer (OC) is still the fourth cause of death by cancer among women and the most fatal among gynecological tumors. The purpose of the symposium held every 2 years in Valencia is to report and discuss new developments in the treatment of OC patients. It also tries to clarify what is evidence-based and what is not. In this issue, proteomic advances for early diagnosis and new tumor markers are presented. Controversies about the role of conservative surgery or the role of surgery in the recurrent disease are discussed. In addition, the current standard treatment, new tendencies on therapy, as well as important aspects related to the molecular era have been updated. Reaching international consensus is a challenge but offers the opportunity to test multiple regimens more efficiently against a single control population, rather than conducting multiple smaller studies. Most of the studies presented in this Symposium were carried out in Gynecologic Cancer Intergroup. If indeed answers to the relevant questions are to be obtained more quickly, then a network of current national or international groups could potentially facilitate this.

Effects of progesterone on ovarian tumorigenesis in xenografted mice

Circumstantial evidence indicates that progestins reduce the risk of epithelial ovarian cancer. We report that the tumorigenic capacity of human ovarian carcinoma (SKOV-3) cells inoculated into the peritoneal cavity of athymic mice is suppressed by pretreatment with subcutaneous progesterone-releasing pellets. Numbers of tumor implants on the intestines/mesentery and invasiveness into underlying host tissues were reduced at 6 weeks following exposure to progesterone. Progesterone prevented tumors from forming on the liver. Life spans of progesterone-treated animals were prolonged. There was no beneficial effect of administration of progesterone if initiated after ovarian tumors had become established on organ surfaces. Our findings implicate a role for progesterone in ovarian cancer prophylaxis.

Ovarian cancer treatment: what is new

Ovarian cancer is still the fourth cause of death by cancer among women and the most fatal among gynecological tumors. The purpose of this symposium is, year after year, to report and discuss the new developments in the treatment of patients with ovarian cancer, the majority of whom still present with advanced disease. It also tries to make it clear to the participants what is evidence-based and what is not. Mature data of both classic studies like GOG-111, OV-10, and more recent studies like GOG-158, AGO-OVAR-3, and the intergroup paclitaxel/epirubicin/carboplatin (TEC) versus paclitaxel/carboplatin (TC) study have been presented. Other current controversial issues included in this edition were sequential single-agent versus simultaneous administration of combination chemotherapy, the role of combination chemotherapy in second-line treatment, the role of consolidation therapy, the role of anthracyclines in the treatment, and cost-effectiviness studies in ovarian cancer. Although the main topic of the symposium is advanced disease, this edition included the results of two parallel randomized studies (ACTION and ICON1) on the treatment of early disease. In addition, new trends in early detection of ovarian cancer have been updated. The pace of new agent development has increased, and it would be helpful to have more efficient preclinical models and early phase-clinical trials to guide the selection of active agents for phase III evaluation. Reaching international consensus is a challenge but offers the opportunity to test multiple regimens more efficiently against a single-control population, rather than conducting multiple smaller studies with redundant internal controls. If indeed answers to the relevant questions are to be obtained more quickly, then, a network of current national or international groups could potentially facilitate this.