Detection of circulating miRNAs : comparative analysis of extracellular vesicle-incorporated miRNAs and cell-free miRNAs in whole plasma of prostate cancer patients

Funding Information: This study was supported by the Norwegian Financial Mechanism 2009–2014 under Project Contract No NFI/R/2014/045. The funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript. Publisher Copyright: © 2017 The Author(s).Background: Circulating cell-free miRNAs have emerged as promising minimally-invasive biomarkers for early detection, prognosis and monitoring of cancer. They can exist in the bloodstream incorporated into extracellular vesicles (EVs) and ribonucleoprotein complexes. However, it is still debated if EVs contain biologically meaningful amounts of miRNAs and may provide a better source of miRNA biomarkers than whole plasma. The aim of this study was to systematically compare the diagnostic potential of prostate cancer-associated miRNAs in whole plasma and in plasma EVs. Methods: RNA was isolated from whole plasma and plasma EV samples from a well characterised cohort of 50 patient with prostate cancer (PC) and 22 patients with benign prostatic hyperplasia (BPH). Nine miRNAs known to have a diagnostic potential for PC in cell-free blood were quantified by RT-qPCR and the relative quantities were compared between patients with PC and BPH and between PC patients with Gleason score ≥ 8 and ≤6. Results: Only a small fraction of the total cell-free miRNA was recovered from the plasma EVs, however the EV-incorporated and whole plasma cell-free miRNA profiles were clearly different. Four of the miRNAs analysed showed a diagnostic potential in our patient cohort. MiR-375 could differentiate between PC and BPH patients when analysed in the whole plasma, while miR-200c-3p and miR-21-5p performed better when analysed in plasma EVs. EV-incorporated but not whole plasma Let-7a-5p level could distinguish PC patients with Gleason score ≥ 8 vs ≤6. Conclusions: This study demonstrates that for some miRNA biomarkers EVs provide a more consistent source of RNA than whole plasma, while other miRNAs show better diagnostic performance when tested in the whole plasma.publishersversionPeer reviewe

The potential for improving colorectal cancer screening efficiency in Latvia

Elektroniskā versija nesatur pielikumusLai veiktu kolorektālā vēža skrīningu, nejauši izvēlētiem 15000 iedzīvotājiem vecumā no 50-74 gadiem, pa pastu nosūtīja vienu no trīs testiem slēpta asins piejaukuma noteikšanai fēcēs – gvajaka (gFOBT), imūnķīmisko – FOB Gold vai OC Sensor. Pusei nosūtīja iepriekšējas informācijas vēstuli; ja aizpildīti testi netika saņemti, nosūtīja atgādinājumu. Pozitīva testa gadījumā uzaicināja veikt kolonoskopiju. Atsaucība bija 31,2% gFOBT, 44,7% FOB Gold un 47,4% OC-Sensor testiem; iepriekšējas informācijas vēstule to uzlaboja maz; 30,9% testu tika saņemti pēc atgādinājuma. Atšķīrās pozitīvo testu proporcija. Kolonoskopiju atsaucība bija 61%. Secināts, ka Latvijā ir iespējams veikt kolorektālā vēža skrīningu, uzaicinot mērķa grupu pa pastu un sasniegt minimālo rekomendēto mērķa grupas atsaucības līmeni. Priekšroka dodama imūnķīmiskiem testiem. Atslēgas vārdi: kolorektālais vēzis, skrīnings, testsistēmaTo perform colorectal cancer screening, inhabitants were sent one of the three faecal occult blood tests by mail – guaiac test (gFOBT), immunochemical FOB Gold or OC-Sensor test. An advance information letter was sent to half of the participants, a reminder to all non-responders. In case of a positive test, screenees were invited to perform colonoscopy. Screening uptake was 31.2% gFOBT, 44.7% FOB Gold and 47.4% for OC-Sensor test groups. An advance information letter improved the uptake slightly; 30.9% of the tests were received after a reminder letter. The ratio of positive tests was different. Colonoscopy uptake was 61%. It was concluded that it is possible to perform colorectal cancer screening in Latvia by inviting target groups by mail and reach the minimum recommended uptake rate. Preference should be given to immunochemical tests. Keywords: colorectal cancer, screening, screening tes

The potential for improving colorectal cancer screening efficiency in Latvia

Elektroniskā versija nesatur pielikumusLai veiktu kolorektālā vēža skrīningu, nejauši izvēlētiem 15000 iedzīvotājiem vecumā no 50-74 gadiem, pa pastu nosūtīja vienu no trīs testiem slēpta asins piejaukuma noteikšanai fēcēs – gvajaka (gFOBT), imūnķīmisko – FOB Gold vai OC Sensor. Pusei nosūtīja iepriekšējas informācijas vēstuli; ja aizpildīti testi netika saņemti, nosūtīja atgādinājumu. Pozitīva testa gadījumā uzaicināja veikt kolonoskopiju. Atsaucība bija 31,2% gFOBT, 44,7% FOB Gold un 47,4% OC-Sensor testiem; iepriekšējas informācijas vēstule to uzlaboja maz; 30,9% testu tika saņemti pēc atgādinājuma. Atšķīrās pozitīvo testu proporcija. Kolonoskopiju atsaucība bija 61%. Secināts, ka Latvijā ir iespējams veikt kolorektālā vēža skrīningu, uzaicinot mērķa grupu pa pastu un sasniegt minimālo rekomendēto mērķa grupas atsaucības līmeni. Priekšroka dodama imūnķīmiskiem testiem. Atslēgas vārdi: kolorektālais vēzis, skrīnings, testsistēmaTo perform colorectal cancer screening, inhabitants were sent one of the three faecal occult blood tests by mail – guaiac test (gFOBT), immunochemical FOB Gold or OC-Sensor test. An advance information letter was sent to half of the participants, a reminder to all non-responders. In case of a positive test, screenees were invited to perform colonoscopy. Screening uptake was 31.2% gFOBT, 44.7% FOB Gold and 47.4% for OC-Sensor test groups. An advance information letter improved the uptake slightly; 30.9% of the tests were received after a reminder letter. The ratio of positive tests was different. Colonoscopy uptake was 61%. It was concluded that it is possible to perform colorectal cancer screening in Latvia by inviting target groups by mail and reach the minimum recommended uptake rate. Preference should be given to immunochemical tests. Keywords: colorectal cancer, screening, screening tes

The Association of Circulating L-Carnitine, γ-Butyrobetaine and Trimethylamine N-Oxide Levels with Gastric Cancer

Our study aimed to evaluate the association between gastric cancer (GC) and higher concentrations of the metabolites L-carnitine, γ-butyrobetaine (GBB) and gut microbiota-mediated trimethylamine N-oxide (TMAO) in the circulation. There is evidence suggesting that higher levels of TMAO and its precursors in blood can be indicative of either a higher risk of malignancy or indeed its presence; however, GC has not been studied in this regard until now. Our study included 83 controls without high-risk stomach lesions and 105 GC cases. Blood serum L-carnitine, GBB and TMAO levels were measured by ultra-high-performance liquid chromatography–mass spectrometry (UPLC/MS/MS). Although there were no significant differences between female control and GC groups, we found a significant difference in circulating levels of metabolites between the male control group and the male GC group, with median levels of L-carnitine reaching 30.22 (25.78–37.57) nmol/mL vs. 37.38 (32.73–42.61) nmol/mL (p p p < 0.05). Thus, our study demonstrated the association between higher blood levels of L-carnitine, GBB, TMAO and GC in males, but not in females. Furthermore, correlations of any two investigated metabolites were stronger in the GC groups of both genders in comparison to the control groups. Our findings reveal the potential role of L-carnitine, GBB and TMAO in GC and suggest metabolic differences between genders. In addition, the logistic regression analysis revealed that the only significant factor in terms of predicting whether the patient belonged to the control or to the GC group was the blood level of L-carnitine in males only. Hence, carnitine might be important as a biomarker or a risk factor for GC, especially in males