Whole Blood DNA Aberrant Methylation in Pancreatic Adenocarcinoma Shows Association with the Course of the Disease: A Pilot Study

Pancreatic tumors are usually diagnosed at an advanced stage in the progression of the disease, thus reducing the survival chances of the patients. Non-invasive early detection would greatly enhance therapy and survival rates. Toward this aim, we investigated in a pilot study the power of methylation changes in whole blood as predictive markers for the detection of pancreatic tumors. We investigated methylation levels at selected CpG sites in the CpG rich regions at the promoter regions of p16, RARbeta, TNFRSF10C, APC, ACIN1, DAPK1, 3OST2, BCL2 and CD44 in the blood of 30 pancreatic tumor patients and in the blood of 49 matching controls. In addition, we studied LINE-1 and Alu repeats using degenerate amplification approach as a surrogate marker for genome-wide methylation. The site-specific methylation measurements at selected CpG sites were done by the SIRPH method. Our results show that in the patient’s blood, tumor suppressor genes were slightly but significantly higher methylated at several CpG sites, while repeats were slightly less methylated compared to control blood. This was found to be significantly associated with higher risk for pancreatic ductal adenocarcinoma. Additionally, high methylation levels at TNFRSCF10C were associated with positive perineural spread of tumor cells, while higher methylation levels of TNFRSF10C and ACIN1 were significantly associated with shorter survival. This pilot study shows that methylation changes in blood could provide a promising method for early detection of pancreatic tumors. However, larger studies must be carried out to explore the clinical usefulness of a whole blood methylation based test for non-invasive early detection of pancreatic tumors

TRANSAXILLARY GASLESS ENDOSCOPIC THYROIDECTOMY VERSUS CONVENTIONAL OPEN THYROIDECTOMY: SYSTEMATIC REVIEW AND META-ANALYSIS

Aim: This systematic review and meta-analysis evaluates surgical outcome and safety results of conventional (OT) versus endoscopic transaxillary gasless thyroidectomies (ET). Material and methods: A systematic literature search was performed. The weighted mean differences or the odd ratios with corresponding 95% CIs were examined for surgical outcomes and complications. The results were analysed using fixed- or random-effects models. The heterogeneity was checked by the Cochran Q test and the extent of inconsistency was evaluated by the I2 statistic. Results: Ten studies and 1597 patients were included. All studies found that ET required longer operative time. Postoperative pain was significantly lower after ET on day 1 and day 7. No statistical difference was found in complication rates. Conclusions: ET has disadvantages such as longer surgery time, but it is a feasible and safe procedure with lower postoperative pain and comparable complication rates to OT. However, good quality prospective randomised studies are necessary to draw firmer conclusions

DNA Methylation of HOXA11 Gene as Prognostic Molecular Marker in Human Gastric Adenocarcinoma

Hypermethylation of tumor suppressor genes and hypomethylation of oncogenes might be identified as possible biomarkers in gastric cancer (GC). We aimed to assess the DNA methylation status of selected genes in GC tissue samples and evaluate these genes’ prognostic importance on patient survival. Patients (99) diagnosed with GC and who underwent gastrectomy were included. We selected a group of genes (RAD51B, GFRA3, AKR7A3, HOXA11, TUSC3, FLI1, SEZ6L, GLDC, NDRG) which may be considered as potential tumor suppressor genes and oncogenes. Methylation of the HOXA11 gene promoter was significantly more frequent in GC tumor tissue (p = 0.006) than in healthy gastric mucosa. The probability of surviving longer (71.2 months (95% CI 57–85.3) vs. 44.3 months (95% CI 34.8–53.9)) was observed with unmethylated HOXA11 promoter in cancer tissues. Survival in patients with a methylation of HOXA11 promoter either in healthy gastric mucosa or gastric cancer tissue was twice as high as in patients with a methylation of HOXA11 promoter in both healthy gastric mucosa and cancer tissue (61.2 months (95% CI 50.9–71.4) vs. 28.5 months (95% CI 20.8–36.2)). Multivariate Cox analysis revealed the HOXA11 methylation as significantly associated with patients’ survival (HR = 2.4, 95% CI 1.19–4.86). Our results suggest that the HOXA11 gene might be a potential prognostic molecular marker in patients with gastric adenocarcinoma

Different stability of miRNAs and endogenous control genes in archival specimens of papillary thyroid carcinoma

Background: The most popular miRNA quantitation technique is RQ-PCR with relative gene expression method that requires an endogenous control (EC) gene for data normalization. However, there are insufficient data and selection criteria on the most suitable ECs for miRNA expression studies in many cancer types including papillary thyroid carcinoma (PTC). Therefore, in this study we evaluated the impact of chosen EC and archival formalin-fixed, paraffin-embedded (FFPE) PTC tissue age on estimated target miRNA expression. Methods: RQ-PCR was used to determine expression levels of five miRNAs (miR-146b, miR-222, miR-21, miR-221 and miR-181b) and three different endogenous controls (RNU48, let-7a, miR-16), which were used to normalize the data. In total, 400 FFPE PTC tissues were analyzed that have been stored from 1 to 15 years. Results: The stability of commonly used ECs RNU48 and let-7a significantly differs from the stability of target miRNA in archival FFPE PTC tissues. Moreover, these differences have a great impact on miRNA expression results when FFPE tissue samples have been stored for a different period of time. Conclusions: It is important to select an ECs not only stable in the tissue of interest but also with similar stability to target miRNA, especially when working with samples of different age

Blood-derived DNA relative methylation is associated with the presence of pancreatic ductal adenocarcinoma in patients.

*<p>Model is adjusted for age groups (<65 years and> = 65 years).</p

Peripheral blood derived DNA mean methylation comparison in cases and controls (Mann-Whitney test).

<p>SD- standard deviation.</p

Clinical characteristics of patients included in this study.

<p>Clinical characteristics of patients included in this study.</p

Heatmap showing p values and significant Spearman correlation coefficient (ρ) between methylation levels of different CpGs in paired peripheral blood and ductal adenocarcinoma tissues (p values of >0.05 are in white, the shown ρ-values are corresponding to p values <0.05).

<p>Heatmap showing p values and significant Spearman correlation coefficient (ρ) between methylation levels of different CpGs in paired peripheral blood and ductal adenocarcinoma tissues (p values of >0.05 are in white, the shown ρ-values are corresponding to p values <0.05).</p

Kaplan-Meier survival estimates of overall survival for methylation levels in peripheral blood of cancer patients. ACIN1 SN1 (A), log rank = 0.012 and TNFRSF10C SN1 (B), log-rank = 0.023.

<p>Kaplan-Meier survival estimates of overall survival for methylation levels in peripheral blood of cancer patients. ACIN1 SN1 (A), log rank = 0.012 and TNFRSF10C SN1 (B), log-rank = 0.023.</p

Distribution of various CpGs relative methylation levels in peripheral blood.

<p>Boxes extend from 25th to 75th percentiles and are divided by a solid line representing the median of each group. Whiskers extend from 5th to 95th percentiles. Each outlier is denoted by a dot.</p