Clinical use of NGS data from the targeted gene panel for mitochondrial diseases screening.

BACKGROUND AND OBJECTIVE: Mitochondrial diseases are a frequent cause of inherited genetic disorders caused by mutations in both the mitochondrial and nuclear human genome. The new technique of high-throughput sequencing, which is used more and more frequently around the world, is most often focused on nuclear DNA. In some cases, such data after proper IT processing could also allow to determine alterations in mtDNA genome. In our work, we want to verify that off-target reads from targeted gene panels are sufficient data to determine pathogenic variants in the mitochondrial genome. METHODS: We analyzed 50 patients who underwent routine diagnostics with the Illumina's TruSight One Sequencing Panel. In the entire bioinformatic analysis process, we have used only free, user-friendly and generally available online tools that do not require specialized IT knowledge. RESULTS: Most of the data obtained were suitable for determining the presence of homoplasmic variants in mtDNA; 84% of the data met the minimum 20-fold coverage requirement as defined in the scientific literature for clinical data. We managed to identify 16 pathogenic variants in the examined genetic material (mtDNA) according to the ClinVar database. CONCLUSIONS: In conclusion, we have outlined that off-target reads from targeted gene panel (TruSight One Sequencing Panel) may also be suitable for determining potentially pathogenic homoplasmic variants in mtDNA. We also described a simple pipeline based only on free tools available online. Introducing such a pipeline into a standard procedure of clinical units which carry out such research undoubtedly can extend the diagnostic potential by information about mtDNA, especially when it is based on purely free tools that do not require specialized bioinformatic knowledge.

Usefulness of droplet digital PCR and Sanger sequencing for detection of FGFR3 mutation in bladder cancer.

OBJECTIVE: The purpose of our research was to determine the usefulness of different methods for detecting Y373C mutation of gene FGFR3. PATIENTS AND METHODS TOTAL: 138 primary bladder cancer patients (71cases G1 and 67 cases G2-G3) were included in the study. Tumor tissue and urine samples were collected and kept frozen until the isolation of DNA. Sanger sequencing was applied for detecting mutation in cancer and ddPCR was utilized for urine assessment. RESULTS: ddPCR appears to be more effective and it identified FGFR3 mutation (Y373C) in urinary sediment in 20.3% of cases whereas Sanger sequencing did in 15.5%. Only in 8/39 (20.5%) cases the mutation was observed both in urine and tissue. In 12/39 (30.8%) cases (5G1 and 7 G2-G3) we did not detect any FGFR3 mutation in urine although it was confirmed by sequencing. We only found mutation in urine in 20/39 cases (15 G1, 5 G2-G3) (51.3%). The correlation between the presence of FGFR3 mutations and better survival was confirmed. The Log-Rank test indicates a significant difference in the likelihood of survival for patients with the FGFR3 mutation but without recurrence (Cox's F-test P = 0.17006; Log-Rank Test P = 0.00059). CONCLUSION: ddPCR appeared to be more sensitive method for detection FGFR3 gene mutation particularly for detecting low levels of tumor DNA amongst a large excess of nontumor DNA. It is significant as the implementation of such markers into routine practice could be beneficial. The prospective study in larger cohort is needed.

Urine miRNA as a potential biomarker for bladder cancer detection - a meta-analysis.

INTRODUCTION: White light cystoscopy (WLC), often supported by urine cytology, is considered the 'goldstandard' in the diagnosis and follow-up of bladder cancer (BCa). In recent years, urine microRNA (miRNA) tests have been performed for the detection of bladder cancer. MATERIAL AND METHODS: A systematic review of the PubMed platform was performed by searching for articles in which miRNA in the urine was used for the detection of BCa. RESULTS: The greatest sensitivity (86.6%) in BCa detection was achieved for multi-miRNA in urine sediment. The greatest specificity (85.3%) was achieved for multi-miRNA from voided urine. There were significant differences (p <0.01) between single-miRNA (OR 8.96; CI 6.37-12.59) and the multi-miRNA group (OR 19.95; CI 13.35-29.81). There were no differences among the specimens (voided urine, supernatant, sediment) used for the test. CONCLUSIONS: Urine miRNAs have the potential to be a valid marker for bladder cancer detection. They can successfully compete with other non-invasive diagnostic tests.

Detection of bladder cancer in urine sediments by a hypermethylation panel of selected tumor suppressor genes.

BACKGROUND: Promoter hypermethylation can be a useful biomarker for early detection and prognosis of bladder cancer, monitoring response to treatment and complement classical diagnostic procedures. OBJECTIVE: The molecular test was performed on DNA from bladder cancer cells in voided urine samples, tumor tissue DNA and normal control DNAs. We aimed to assess the diagnostic potential of epigenetic changes in urine DNA from bladder cancer cases at various clinico-pathological stages of the disease. METHODS: The methylation status of 5 genes (p14ARF, p16INK4A, RASSF1A, DAPK, APC) in 113 tumor samples paired with voided urine specimens was analyzed by MSP. We compared the results of methylation analysis with UroVysion test. RESULTS: The methylation profile in tumor/urine DNA was significantly correlated (p ≤ 0,05) with tumor grade in p14ARF, RASSF1a, APC/p14ARF, APC genes, respectively and with stage in p14ARF, RASSF1a/p14ARF genes, respectively. The results of UroVysion test were in correlation with hypermethylation both in tumor and urine DNA in p14ARF, RASSF1a and APC genes (p = 0,008; 0,02 and 0,04, respectively). CONCLUSIONS: Promoter hypermethylation of tumor suppressor genes is a frequent mechanism in bladder cancer. We found promoter hypermethylation in all grades and stages of all cases examined. Methylation profile of selected suppressor genes may be a potential useful biomarker and enhance early detection of bladder cancer using a noninvasive urine test.