Quadriplex model enhances urine-based detection of prostate cancer

Konference: 2011 7. Sympozium a workshop molekulární patologie a histo-cyto-chemie

Kategorie: Onkologická diagnostika

Téma: Postery

Číslo abstraktu: 002p

Autoři: T. Jamaspishvili; MUDr. Milan Král, Ph.D.; I. Khomeriki; MUDr. Vlasta Vyhnánková; Mgr. Giorgi Mgebrishvili; Doc.MUDr. Vladimír Študent, Ph.D.; prof. MUDr. Zdeněk Kolář, CSc.; Mgr. Jan Bouchal

Background: The major advantages of multiplex urine-based assays are their noninvasive character, ability to monitor prostate cancer (CaP) with heterogeneous foci and detect cancer more accurately than do single marker tests. They might supplement serum PSA test which has low specificity resulting in a number of unnecessary biopsies especially in ‚grey zone‘ and thereby reducing complications associated with biopsy. While the test for the prostate cancer gene 3 (PCA3) is commercially available, the aim of our research was to test other putative urine markers in multiplex settings (AMACR, EZH2, GOLM1, MSMB, SPINK1 and TRPM8).

Materials and methods: Expression of the candidate biomarkers was studied in sedimented urine using quantitative RT-PCR on two sets of patients with PSA levels of 3-15 ng/ml (N=104) and 0.1-587 ng/ml (N=176). Total RNA isolation was performed by the Urine Exfoliated Cell RNA Purification Kit (Fisher Scientific, USA), quantified by Nanodrop, pretreated with Dnase I (Invitrogen) and reverse transcribed with SuperScript® III Reverse Transcriptase (Invitrogen), preamplified and tested on real-time PCR with Light Cycler® 480 (Roche). Clinicopathological characteristics were defined according to the WHO classification. Statistical analysis was done in SPSS using Spearman, Mann-Whitney and ROC analysis. Univariate and multivariate regression analysis were used to determine predicted probability of the individual markers and their combinations.

Results and discussion: We confirmed that PCA3 is an independent predictor of cancer in the patients without restriction of serum PSA values (0.1-587 ng/ml). However, AMACR was the only parameter that differentiated CaP from nonCaP patients in patients with serum PSA between 3 and 15 ng/ml. The area under curve (AUC) for this gene was 0.645 with both sensitivity and specificity at 65%. Further improvement was achieved by multivariate logistic regression analysis which identified novel duplex (TRPM8 and MSMB), triplex (plus AMACR) and quadriplex (plus PCA3) models for the detection of early prostate cancers (AUC 0.665, 0.726 and 0.741, respectively).

Conclusions: In the current study we demonstrated that novel qudriplex test could be implemented as an adjunct to serum PSA or urine PCA3 and this could improve decision making for diagnostics in the case of ‘PSA dilemma’ patients.

This work was supported by grants NS 9940-4 from the Czech Ministry of Health and MSM 6198959216 from the Czech Ministry of Education and EU infrastructure support CZ.1.05/2.1.00/01.0030. Tamar Jamaspishvili was also supported by GACR 303/09/H048 from the Grant Agency of the Czech Republic and LF_2010_006.

Datum přednesení příspěvku: 29. 4. 2011