Determination of expression signature and proportion of mtDNA in plasma fractions in patients with Renal Cell Carcinoma.

Renal Cell Carcinoma (RCC) is the third most common urologic malignancy,remains one of the most lethal urological malignancies, preferably in developed countries. The incidence and mortality rates differ significantly according to sex, race, age and external factors such as smoking, obesity and hypertension increasing RCC risk. The use of novel predictive biomarkers is currently being increased as these improve the diagnosis, progression and prognosis of RCC. Since recent studies have demonstrated a promising association between mitocondrial DNA (mtDNA) copy number alteration in peripheral blood and risk of developing RCC, we conducted a case-control study to determine exosomes mtDNA content in plasma fractions as a potential novel non-invasive biomarker in liquid biopsy in order to monitor the RCC status in patients.

In this way, plasma fractions highly purified in exosomes were obtained from blood samples from controls and RCC cases, and relative mtDNA content was measured by quantitative real-time polymerase chain reaction (qPCR). Our results show fragment size distribution profile and the copy numbers of nuclear regions and mitochondrial genes (in hypervariable and conserved regions) in each plasma fraction.