Integrity and amplification of nucleic acids from snap-frozen prostate tissues from robotic-assisted laparoscopic and...

Recently, robotic-assisted laparoscopic prostatectomy has replaced open retropubic radical prostatectomy as the surgical procedure of choice. This less-invasive approach offers many advantages but exposes prostate tissue to longer periods of warm ischemia that may affect subsequent analysis of biomarkers.

To analyze the nucleic acid quality and quantity isolated from open versus laparoscopic prostatectomies.

Nucleic acids were isolated from 10 open-obtained and 10 laparoscopic-obtained tissues stored in our prostate sample repository. Nucleic acid integrity was assessed via electrophoresis and polymerase chain reaction amplification of RNA and DNA targets ranging in size from 125 to 939 base pairs.

The DNA yield, integrity, and polymerase chain reaction amplification were identical between samples obtained from both surgical approaches. The RNA integrity number and yield were similar, as was β-2 microglobulin mRNA amplification up to 652 base pairs. However, 2 of 10 samples (20%) collected robotically showed decreased real-time reverse transcriptase-polymerase chain reaction amplification of prostate-specific antigen messenger RNA, especially with targets larger than 300 base pairs.

Generally, the quality and quantity of nucleic acids isolated from prostate tissue obtained via open or laparoscopic approaches are equivalent, suggesting that procurement of tissues is appropriate from either procedure. However, some loss of reverse transcriptase-polymerase chain reaction amplification of larger RNA targets was noted in the laparoscopic samples; appropriate design of assays to keep amplicon sizes small and the use of internal controls to assess RNA integrity is recommended.