Are elevated mitochondrial DNA fragments in prostatic inflammation a potential biomarker for prostate cancer?

Abstract

Background: We sought to determine whether two soluble forms with different size of mtDNA are linked to prostatic inflammation, and whether they discriminate prostate cancer (PCa) from inflammatory prostatic conditions. Methods: Histopathologically diagnosed prostatitis, PCa and benign prostatic hyperplasia patients (n = 93) were enrolled in this study and they were categorized as with and without prostate inflammation. Quantitative RT-PCR was used to analyze the levels of 79-bp and 230-bp fragments in urine and blood samples collected following prostate massage. Results: The urine mtDNA-79 and mtDNA-230 were significantly increased in patients with prostate inflammation compared with those in without inflammation. Here, 79-bp fragment of apoptotic origin was significantly higher level than 230-bp fragment of necrotic origin. Although mtDNA-79 copy number in serum samples was also increased in patients with prostate inflammation, mtDNA-230 was similar in the two groups. Furthermore, mtDNA-79 and mtDNA-230 copy numbers in postprostate massage urine were higher (about 16-fold and 22-fold, respectively) than those from serum samples. ROC analysis showed that, although post-prostate massage urine have relatively higher performance than blood, ability to discriminate cases of both fragments was not better than that of serum total PSA. Conclusions: Our results demonstrate that shorter cf-mtDNA fragment size in particular, increase in the presence of prostate inflammation in post-prostatic massage urine but both fragments could never improve serum total PSA performance.

Keywords

• prostate
• inflammation
• cancer
• mitochondrial DNA
• post-prostatic massage