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Detection of Alpha-Methylacyl-CoA Racemase (AMACR), a Biomarker of Prostate Cancer, in Patient Blood Samples Using a Nanoparticle Electrochemical Biosensor.

Lin PY, Cheng KL, McGuffin-Cawley JD, Shieu FS, Samia AC, Gupta S, Cooney M, Thompson CL, Liu CC - Biosensors (Basel) (2012)

Bottom Line: However, no accurate clinically useful assay has been developed.This study reports the development of a single use, disposable biosensor for AMACR detection.Human blood samples were used to verify its validity, reproducibility and reliability.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science & Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. ppl3@case.edu.

ABSTRACT
Although still commonly used in clinical practice to screen and diagnose prostate cancer, there are numerous weaknesses of prostate-specific antigen (PSA) testing, including lack of specificity and the inability to distinguish between aggressive and indolent cancers. A promising prostate cancer biomarker, alpha-methylacyl-CoA racemase (AMACR), has been previously demonstrated to distinguish cancer from healthy and benign prostate cells with high sensitivity and specificity. However, no accurate clinically useful assay has been developed. This study reports the development of a single use, disposable biosensor for AMACR detection. Human blood samples were used to verify its validity, reproducibility and reliability. Plasma samples from 9 healthy males, 10 patients with high grade prostatic intraepithelial neoplasia (HGPIN), and 5 prostate cancer patients were measured for AMACR levels. The average AMACR levels in the prostate cancer patients was 10 fold higher (mean(SD) = 0.077 (0.10)) than either the controls (mean(SD) = 0.005 (0.001)) or HGPIN patients (mean(SD) = 0.004 (0.0005)). At a cutoff of between 0.08 and 0.9, we are able to achieve 100% accuracy in separating prostate cancer patients from controls. Our results provide strong evidence demonstrating that this biosensor can perform as a reliable assay for prostate cancer detection and diagnosis.

No MeSH data available.


Related in: MedlinePlus

Cyclic Voltammograms of control sample solutions of PBS media, PBS + pristanic acid (a), and PBS + AMACR (0.0065 µg/µL) (b), The CVs obtained show that pristanic acid and AMACR do not contribute to any current measured by the Ir-nanoparticle based prototype biosensor. (c) Cyclic Voltammograms obtained from test solutions containing pristanic acid, in the absence and presence of the enzymes ACOX3 and AMACR, respectively.
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biosensors-02-00377-f003: Cyclic Voltammograms of control sample solutions of PBS media, PBS + pristanic acid (a), and PBS + AMACR (0.0065 µg/µL) (b), The CVs obtained show that pristanic acid and AMACR do not contribute to any current measured by the Ir-nanoparticle based prototype biosensor. (c) Cyclic Voltammograms obtained from test solutions containing pristanic acid, in the absence and presence of the enzymes ACOX3 and AMACR, respectively.

Mentions: Hydrogen peroxide, H2O2, is an electrochemically active species, which can be oxidized or reduced under appropriate conditions. Normally, at approximately +0.40 to 0.45 V versus a Ag/AgCl reference electrode, H2O2 can be oxidized yielding an oxidation current which corresponds to the quantity of H2O2 present. With the incorporation of the IrO nano-catalyst, the overpotential of the oxidation of H2O2 becomes lower and H2O2 in phosphate buffer solution (PBS). This represents the advantage and uniqueness of this biosensor. The sensitivity of the IrO catalyst biosensor for H2O2 detection in PBS has been reported elsewhere [30], and the biosensor is used in the AMACR measurement as shown in Figure 1. However, there is no direct calibration of H2O2 using AMACR contained samples, because the H2O2 generated in the patient blood samples is low comparing the calibration of H2O2 in PBS. The calibration of the biosensor is carried out directly using the blood samples of the patients and the testing solutions of known AMACR. The detection approach and the reaction mechanism shown in Figure 1 can only be applicable for AMACR detection, if all the chemical species involved in the reactions will not contribute to any oxidation current of the H2O2 produced. This can be validated by carrying out the cyclic voltammetric studies of the chemicals involved. Figure 3 shows the cyclic voltammetric studies indicating that the chemicals used will not contribute to the oxidation current of hydrogen peroxide produced in Figure 1.


Detection of Alpha-Methylacyl-CoA Racemase (AMACR), a Biomarker of Prostate Cancer, in Patient Blood Samples Using a Nanoparticle Electrochemical Biosensor.

Lin PY, Cheng KL, McGuffin-Cawley JD, Shieu FS, Samia AC, Gupta S, Cooney M, Thompson CL, Liu CC - Biosensors (Basel) (2012)

Cyclic Voltammograms of control sample solutions of PBS media, PBS + pristanic acid (a), and PBS + AMACR (0.0065 µg/µL) (b), The CVs obtained show that pristanic acid and AMACR do not contribute to any current measured by the Ir-nanoparticle based prototype biosensor. (c) Cyclic Voltammograms obtained from test solutions containing pristanic acid, in the absence and presence of the enzymes ACOX3 and AMACR, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263563&req=5

biosensors-02-00377-f003: Cyclic Voltammograms of control sample solutions of PBS media, PBS + pristanic acid (a), and PBS + AMACR (0.0065 µg/µL) (b), The CVs obtained show that pristanic acid and AMACR do not contribute to any current measured by the Ir-nanoparticle based prototype biosensor. (c) Cyclic Voltammograms obtained from test solutions containing pristanic acid, in the absence and presence of the enzymes ACOX3 and AMACR, respectively.
Mentions: Hydrogen peroxide, H2O2, is an electrochemically active species, which can be oxidized or reduced under appropriate conditions. Normally, at approximately +0.40 to 0.45 V versus a Ag/AgCl reference electrode, H2O2 can be oxidized yielding an oxidation current which corresponds to the quantity of H2O2 present. With the incorporation of the IrO nano-catalyst, the overpotential of the oxidation of H2O2 becomes lower and H2O2 in phosphate buffer solution (PBS). This represents the advantage and uniqueness of this biosensor. The sensitivity of the IrO catalyst biosensor for H2O2 detection in PBS has been reported elsewhere [30], and the biosensor is used in the AMACR measurement as shown in Figure 1. However, there is no direct calibration of H2O2 using AMACR contained samples, because the H2O2 generated in the patient blood samples is low comparing the calibration of H2O2 in PBS. The calibration of the biosensor is carried out directly using the blood samples of the patients and the testing solutions of known AMACR. The detection approach and the reaction mechanism shown in Figure 1 can only be applicable for AMACR detection, if all the chemical species involved in the reactions will not contribute to any oxidation current of the H2O2 produced. This can be validated by carrying out the cyclic voltammetric studies of the chemicals involved. Figure 3 shows the cyclic voltammetric studies indicating that the chemicals used will not contribute to the oxidation current of hydrogen peroxide produced in Figure 1.

Bottom Line: However, no accurate clinically useful assay has been developed.This study reports the development of a single use, disposable biosensor for AMACR detection.Human blood samples were used to verify its validity, reproducibility and reliability.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science & Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. ppl3@case.edu.

ABSTRACT
Although still commonly used in clinical practice to screen and diagnose prostate cancer, there are numerous weaknesses of prostate-specific antigen (PSA) testing, including lack of specificity and the inability to distinguish between aggressive and indolent cancers. A promising prostate cancer biomarker, alpha-methylacyl-CoA racemase (AMACR), has been previously demonstrated to distinguish cancer from healthy and benign prostate cells with high sensitivity and specificity. However, no accurate clinically useful assay has been developed. This study reports the development of a single use, disposable biosensor for AMACR detection. Human blood samples were used to verify its validity, reproducibility and reliability. Plasma samples from 9 healthy males, 10 patients with high grade prostatic intraepithelial neoplasia (HGPIN), and 5 prostate cancer patients were measured for AMACR levels. The average AMACR levels in the prostate cancer patients was 10 fold higher (mean(SD) = 0.077 (0.10)) than either the controls (mean(SD) = 0.005 (0.001)) or HGPIN patients (mean(SD) = 0.004 (0.0005)). At a cutoff of between 0.08 and 0.9, we are able to achieve 100% accuracy in separating prostate cancer patients from controls. Our results provide strong evidence demonstrating that this biosensor can perform as a reliable assay for prostate cancer detection and diagnosis.

No MeSH data available.


Related in: MedlinePlus