Alternative tumor markers in the diagnosis of ovarian cancer.

OBJECTIVES: The aim of the study was to assess the usefulness of various tumor markers (CA125, HE4, bcl2) measured in serum, urine and saliva in the differential diagnosis of adnexal masses. MATERIAL AND METHODS: Our study was conducted at the Baskent University Medical School, Department of Obstetrics and Gynecology, Ankara, Turkey, between November 2010 and March 2011. Fifty patients with a suspicion of malignant adnexal mass and 30 controls were included in the study. Serum and urine CA-125, HE4, and bcl2 levels were evaluated for their role in the diagnosis of epithelial ovarian cancer (EOC). RESULTS: Serum CA-125 and HE4 levels, and urine HE4 levels were significantly higher in malignant cases as compared to controls (p < 0.05). Mean levels of bcl2 in saliva and urine were similar in malignant cases and controls (p > 0.05). CONCLUSIONS: We demonstrated that serum CA125, serum HE4 and urine HE4 levels were elevated in patients with ovarian cancer. These findings should be assessed in future studies with larger sample sizes in order to reach more definite conclusions.

Surface modification on acoustic wave biosensors for enhanced specificity.

Changes in mass loading on the surface of acoustic biosensors result in output frequency shifts which provide precise measurements of analytes. Therefore, to detect a particular biomarker, the sensor delay path must be judiciously designed to maximize sensitivity and specificity. B-cell lymphoma 2 protein (Bcl-2) found in urine is under investigation as a biomarker for non-invasive early detection of ovarian cancer. In this study, surface chemistry and biofunctionalization approaches were evaluated for their effectiveness in presenting antibodies for Bcl-2 capture while minimizing non-specific protein adsorption. The optimal combination of sequentially adsorbing protein A/G, anti-Bcl-2 IgG and Pluronic F127 onto a hydrophobic surface provided the greatest signal-to-noise ratio and enabled the reliable detection of Bcl-2 concentrations below that previously identified for early stage ovarian cancer as characterized by a modified ELISA method. Finally, the optimal surface modification was applied to a prototype acoustic device and the frequency shift for a range of Bcl-2 concentration was quantified to demonstrate the effectiveness in surface acoustic wave (SAW)-based detection applications. The surface functionalization approaches demonstrated here to specifically and sensitively detect Bcl-2 in a working ultrasonic MEMS biosensor prototype can easily be modified to detect additional biomarkers and enhance other acoustic biosensors.

A urinary Bcl-2 surface acoustic wave biosensor for early ovarian cancer detection.

In this study, the design, fabrication, surface functionalization and experimental characterization of an ultrasonic MEMS biosensor for urinary anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) detection with sub ng/mL sensitivity is presented. It was previously shown that urinary Bcl-2 levels are reliably elevated during early and late stages of ovarian cancer. Our biosensor uses shear horizontal (SH) surface acoustic waves (SAWs) on surface functionalized ST-cut Quartz to quantify the mass loading change by protein adhesion to the delay path. SH-SAWs were generated and received by a pair of micro-fabricated interdigital transducers (IDTs) separated by a judiciously designed delay path. The delay path was surface-functionalized with monoclonal antibodies, ODMS, Protein A/G and Pluronic F127 for optimal Bcl-2 capture with minimal non-specific adsorption. Bcl-2 concentrations were quantified by the resulting resonance frequency shift detected by a custom designed resonator circuit. The target sensitivity for diagnosis and identifying the stage of ovarian cancer was successfully achieved with demonstrated Bcl-2 detection capability of 500 pg/mL. It was also shown that resonance frequency shift increases linearly with increasing Bcl-2 concentration.

Urinary levels of Bcl-2 are elevated in ovarian cancer patients.

OBJECTIVE(S): The poor prognosis associated with ovarian cancer is due to the lack of overt early symptoms and the absence of reliable diagnostic screening methods. Since many tumors overexpress anti-apoptotic proteins, the purpose of this study was to determine whether elevated levels of the anti-apoptotic protein Bcl-2 were present in urine from patients with ovarian cancer. METHODS: Bcl-2 was assayed by ELISA in urine samples from two cohorts consisting of a total of 77 healthy women, 161 women with benign gynecologic disease and 150 women with ovarian cancer, 13 with early and 137 with late stage disease, respectively. Wherever possible, parallel serum samples were measured for CA125 levels by ELISA. RESULTS: Urinary levels of Bcl-2 from healthy individuals or women with benign disease averaged 0.59 ng/ml+/-0.61 and 1.12 ng/ml+/-0.79, respectively. In contrast, urinary levels of Bcl-2 averaged 2.60 ng/ml+/-2.23 and 3.58 ng/ml+/-1.55 from women with early (N=13) and late (N=137) stage ovarian cancer. Further, urinary levels of Bcl-2 were elevated in ovarian cancer patients regardless of tumor grade, stage, size, histologic subtype, creatinine levels or patient age, but appeared to complement CA125 measurements. CONCLUSION(S): Levels of Bcl-2 are elevated in the urine of patients with ovarian cancer and may be of diagnostic and/or prognostic clinical importance. Further studies of urinary Bcl-2 as a biomarker for ovarian cancer alone or in combination with other markers are warranted.