Tissue-based Quantification of 8-Hydroxy-2′-Deoxyguanosine in Human Prostate Biopsies Using Quantitative Fluorescence Imaging Analysis

Objectives: To quantify 8-hydroxy-2′-deoxyguanosine (8-OHdG) in prostate stromal and acini tissue compartments from benign and cancer-containing prostate specimens using a new quantitative fluorescence imaging analysis protocol. Methods: Prostate biopsy specimens from 20 age-matched benign (control) and cancer-containing tissue sections were used to quantify 8-OHdG. 8-OHdG was quantified within individual acini nuclei and the surrounding stroma nuclei. Paraffin sections were treated with RNAse and protease to expose the nuclear chromatin, reacted with anti-8-OHdG mouse monoclonal antibody bound to saturation and detected with secondary goat anti-mouse IgG labeled with Alex Fluor 488, and quantified with a calibrated quantitative fluorescence imaging analysis system. The results were analyzed using a paired Student's t test. Results: 8-OHdG was successfully quantified within individual cellular compartments without the need for laser tissue dissection, using the mean pixel intensity of fluorescent-labeled 8-OHdG. Matched-pair analysis of the global expression of 8-OHdG, as well as the acini and stroma individually, revealed no difference between the cancerous and control prostatic tissue. All patients with prostate cancer and those with benign findings had significantly greater 8-OHdG within the acini compared with the surrounding stoma (P < .05). Conclusions: A protocol to quantify 8-OHdG in paraffin-embedded human prostatic tissue was successfully developed. 8-OHdG was not significantly elevated in the acini or stroma of cancer-containing prostatic tissue compared with age-matched benign prostatic tissue. Although 8-OHdG was significantly elevated in the acini nuclei compared with the surrounding stroma nuclei in both cancer-containing and benign prostatic tissue, it, by itself, was not a strong biomarker for prostate cancer risk assessment.