Serum Biomarker Identified for Prostate Cancer

Molecular methods have been used to identify micro ribonucleic acids (miRNAs) in serum, which can serve as biomarkers for prostate cancer.

Noncoding miRNAs in the serum and plasma have been shown to have potential as noninvasive markers for physiological and pathological conditions including malignancy.

Scientists at the University of California San Francisco (UCSF; San Francisco, CA, USA), have developed a multiplex quantitative reverse transcription polymerase chain reaction (qRT-PCR) method involving purification of multiplex PCR products followed by uniplex analysis to identify miRNAs. They used a microfluidics chip to evaluate 384 human miRNAs using small RNA deficient knockout mouse cells as the benchmark. The investigators confirmed the validity of their technique, while uncovering a significant lack of accuracy in previously published methods.

The scientists profiled 48 sera from healthy men and untreated prostate cancer patients with differing Cancer of the Prostate Risk Assessment scores. They identified miRNA signatures that allowed them to diagnose cancer patients and correlate with prognosis. These serum signatures included oncogenic and tumor suppressive miRNAs suggesting functional roles in prostate cancer progression. The uniplex analysis was performed on the microfluidics chip produced by Fluidigm Corporation (South San Francisco, CA, USA).

The Fluidigm BioMark System transforms the way that scientists can perform high-throughput real-time quantitative PCR (qPCR) studies. The BioMark System uses microfluidic chips and features low input requirements providing the sensitivity and assay throughput necessary for qPCR. Fluidigm's proprietary Integrated Fluidic Circuit technology enables single-cell discovery with the ability to screen hundreds of genes from single cells using standard TaqMan and DNA binding dye assays.

The authors concluded that the modified qRT-PCR demonstrated that primer carry-over from the multiplex PCR has detrimental effects on miRNA quantification. This technique used on a nanoliter scale on a microfluidic chip allows for high-throughput multiplex qRT-PCR in a timely and cost-effective manner. The study was published on January 15, 2011, in Cancer Research.

Related Links:
University of California San Francisco
Fluidigm Corporation