biostudies-literatureOtto JJNational Cancer InstituteNCI NIH HHSe2000012https://www.ebi.ac.uk/biostudies/studies/S-EPMC7674190biostudies-literatureUnknown14(6)<h4>Purpose</h4>The rs17632542 single nucleotide polymorphism (SNP) results in lower serum prostate specific antigen (PSA) levels which may further mitigate against its clinical utility as a prostate cancer biomarker. Post-digital rectal exam (post-DRE) urine is a minimally invasive fluid that is currently utilized in prostate cancer diagnosis. To detect and quantitate the variant protein in urine.<h4>Experimental design</h4>Fifty-three post-DRE urines from rs17632542 genotyped individuals processed and analyzed by liquid chromatography/mass spectrometry (LC-MS) in a double-blinded randomized study. The ability to distinguish between homozygous wild-type, heterozygous, or homozygous variant is examined before unblinding.<h4>Results</h4>Stable-isotope labeled peptides are used in the detectProteomics. Clinical applicationsTargeted Mass Spectrometry of a Clinically Relevant PSA Variant from Post-DRE Urines for Quantitation and Genotype Determination.PMC7674190P30CA016042P30 CA016042U01CA086402U01 CA214194U01CA214194P30CA054174P50 CA211015Albracht BLiss MSemmes OJCorrell VLOtto JJMain BPYang LFKislinger TBoutros PCHitefield NLLeach RJJohnson-Pais TNyalwidhe JOEngstroem HAfalseTargeted Mass Spectrometry of a Clinically Relevant PSA Variant from Post-DRE Urines for Quantitation and Genotype Determination.<h4>Purpose</h4>The rs17632542 single nucleotide polymorphism (SNP) results in lower serum prostate specific antigen (PSA) levels which may further mitigate against its clinical utility as a prostate cancer biomarker. Post-digital rectal exam (post-DRE) urine is a minimally invasive fluid that is currently utilized in prostate cancer diagnosis. To detect and quantitate the variant protein in urine.<h4>Experimental design</h4>Fifty-three post-DRE urines from rs17632542 genotyped individuals processed and analyzed by liquid chromatography/mass spectrometry (LC-MS) in a double-blinded randomized study. The ability to distinguish between homozygous wild-type, heterozygous, or homozygous variant is examined before unblinding.<h4>Results</h4>Stable-isotope labeled peptides are used in the detect2020-01-01T00:00:00Z2020 Nov2026-04-30T15:59:59.729Z2021-02-20T17:42:06ZS-EPMC76741903261414110.1002/prca.202000012