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Molecular assays for the detection of prostate tumor derived nucleic acids in peripheral blood.

Jost M, Day JR, Slaughter R, Koreckij TD, Gonzales D, Kinnunen M, Groskopf J, Rittenhouse HG, Vessella RL, Reynolds MA - Mol. Cancer (2010)

Bottom Line: In our experiments, anti-EpCAM magnetic particles alone exhibited equivalent or better analytical performance with patient samples compared to a combination of anti-EpCAM + anti-PSMA magnetic particles.Interestingly, for the vast majority of men who tested positive for PSA mRNA following CTC enrichment, their matched plasma samples also tested positive, although CTC enrichment gave higher overall mRNA copy numbers.Our results indicate that men who test positive following CTC enrichment also exhibit higher detectable levels of non-cellular, circulating prostate-specific mRNAs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Gen-Probe Incorporated, San Diego, CA 92121, USA.

ABSTRACT

Background: Prostate cancer is the second leading cause of cancer mortality in American men. Although serum PSA testing is widely used for early detection, more specific prognostic tests are needed to guide treatment decisions. Recently, the enumeration of circulating prostate epithelial cells has been shown to correlate with disease recurrence and metastasis following definitive treatment. The purpose of our study was to investigate an immunomagnetic fractionation procedure to enrich circulating prostate tumor cells (CTCs) from peripheral blood specimens, and to apply amplified molecular assays for the detection of prostate-specific markers (PSA, PCA3 and TMPRSS2:ERG gene fusion mRNAs).

Results: As few as five prostate cancer cells were detected per 5 mL of whole blood in model system experiments using anti-EpCAM magnetic particles alone or in combination with anti-PSMA magnetic particles. In our experiments, anti-EpCAM magnetic particles alone exhibited equivalent or better analytical performance with patient samples compared to a combination of anti-EpCAM + anti-PSMA magnetic particles. Up to 39% of men with advanced prostate cancer tested positive with one or more of the molecular assays tested, whereas control samples from men with benign prostate hyperplasia gave consistently negative results as expected. Interestingly, for the vast majority of men who tested positive for PSA mRNA following CTC enrichment, their matched plasma samples also tested positive, although CTC enrichment gave higher overall mRNA copy numbers.

Conclusion: CTCs were successfully enriched and detected in men with advanced prostate cancer using an immunomagnetic enrichment procedure coupled with amplified molecular assays for PSA, PCA3, and TMPRSS2:ERG gene fusion mRNAs. Our results indicate that men who test positive following CTC enrichment also exhibit higher detectable levels of non-cellular, circulating prostate-specific mRNAs.

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Related in: MedlinePlus

Comparison of matched CTC enriched blood fractions using either dual antibody (anti-PSMA plus anti-EpCAM) or single antibody (anti-EpCAM alone) magnetic particle formulations.
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Related In: Results  -  Collection

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Figure 3: Comparison of matched CTC enriched blood fractions using either dual antibody (anti-PSMA plus anti-EpCAM) or single antibody (anti-EpCAM alone) magnetic particle formulations.

Mentions: Figure 3 shows a comparison of PSA mRNA signals from CTC enriched samples where sufficient blood volume had been collected from the patient to allow a comparison between the single antibody (anti-EpCAM) and dual antibody (anti-EpCAM plus anti-PSMA) magnetic particle formulations. The single antibody formulation detected 8/14 cases (57%); whereas the dual antibody formulation detected 7/14 cases (50%), with the majority of positives from androgen-independent patients. We were unable to measure any synergistic effect of the dual antibody magnetic bead formulation in this experiment (see Discussion).


Molecular assays for the detection of prostate tumor derived nucleic acids in peripheral blood.

Jost M, Day JR, Slaughter R, Koreckij TD, Gonzales D, Kinnunen M, Groskopf J, Rittenhouse HG, Vessella RL, Reynolds MA - Mol. Cancer (2010)

Comparison of matched CTC enriched blood fractions using either dual antibody (anti-PSMA plus anti-EpCAM) or single antibody (anti-EpCAM alone) magnetic particle formulations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2903503&req=5

Figure 3: Comparison of matched CTC enriched blood fractions using either dual antibody (anti-PSMA plus anti-EpCAM) or single antibody (anti-EpCAM alone) magnetic particle formulations.
Mentions: Figure 3 shows a comparison of PSA mRNA signals from CTC enriched samples where sufficient blood volume had been collected from the patient to allow a comparison between the single antibody (anti-EpCAM) and dual antibody (anti-EpCAM plus anti-PSMA) magnetic particle formulations. The single antibody formulation detected 8/14 cases (57%); whereas the dual antibody formulation detected 7/14 cases (50%), with the majority of positives from androgen-independent patients. We were unable to measure any synergistic effect of the dual antibody magnetic bead formulation in this experiment (see Discussion).

Bottom Line: In our experiments, anti-EpCAM magnetic particles alone exhibited equivalent or better analytical performance with patient samples compared to a combination of anti-EpCAM + anti-PSMA magnetic particles.Interestingly, for the vast majority of men who tested positive for PSA mRNA following CTC enrichment, their matched plasma samples also tested positive, although CTC enrichment gave higher overall mRNA copy numbers.Our results indicate that men who test positive following CTC enrichment also exhibit higher detectable levels of non-cellular, circulating prostate-specific mRNAs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Gen-Probe Incorporated, San Diego, CA 92121, USA.

ABSTRACT

Background: Prostate cancer is the second leading cause of cancer mortality in American men. Although serum PSA testing is widely used for early detection, more specific prognostic tests are needed to guide treatment decisions. Recently, the enumeration of circulating prostate epithelial cells has been shown to correlate with disease recurrence and metastasis following definitive treatment. The purpose of our study was to investigate an immunomagnetic fractionation procedure to enrich circulating prostate tumor cells (CTCs) from peripheral blood specimens, and to apply amplified molecular assays for the detection of prostate-specific markers (PSA, PCA3 and TMPRSS2:ERG gene fusion mRNAs).

Results: As few as five prostate cancer cells were detected per 5 mL of whole blood in model system experiments using anti-EpCAM magnetic particles alone or in combination with anti-PSMA magnetic particles. In our experiments, anti-EpCAM magnetic particles alone exhibited equivalent or better analytical performance with patient samples compared to a combination of anti-EpCAM + anti-PSMA magnetic particles. Up to 39% of men with advanced prostate cancer tested positive with one or more of the molecular assays tested, whereas control samples from men with benign prostate hyperplasia gave consistently negative results as expected. Interestingly, for the vast majority of men who tested positive for PSA mRNA following CTC enrichment, their matched plasma samples also tested positive, although CTC enrichment gave higher overall mRNA copy numbers.

Conclusion: CTCs were successfully enriched and detected in men with advanced prostate cancer using an immunomagnetic enrichment procedure coupled with amplified molecular assays for PSA, PCA3, and TMPRSS2:ERG gene fusion mRNAs. Our results indicate that men who test positive following CTC enrichment also exhibit higher detectable levels of non-cellular, circulating prostate-specific mRNAs.

Show MeSH
Related in: MedlinePlus