High-intensity interval training (HIIT) is a time-efficient way of improving physical performance in healthy subjects and in patients with common chronic diseases, but less so in elite endurance athletes. The mechanisms underlying the effectiveness of HIIT are uncertain. Here, recreationally active human subjects performed highly demanding HIIT consisting of 30-s bouts of all-out cycling with 4-min rest in between bouts (≤3 min total exercise time). Skeletal muscle biopsies taken 24 h after the HIIT exercise showed an extensive fragmentation of the sarcoplasmic reticulum (SR) Ca 2+ release channel, the ryanodine receptor type 1 (RyR1). The HIIT exercise also caused a prolonged force depression and triggered major changes in the expression of genes related to endurance exercise. Subsequent experiments on elite endurance athletes performing the same HIIT exercise showed no RyR1 fragmentation or prolonged changes in the expression of endurance-related genes. Finally, mechanistic experiments performed on isolated mouse muscles exposed to HIIT-mimicking stimulation showed reactive oxygen/nitrogen species (ROS)-dependent RyR1 fragmentation, calpain activation, increased SR Ca 2+ leak at rest, and depressed force production due to impaired SR Ca 2+ release upon stimulation. In conclusion, HIIT exercise induces a ROSdependent RyR1 fragmentation in muscles of recreationally active subjects, and the resulting changes in muscle fiber Ca 2+ -handling trigger muscular adaptations. However, the same HIIT exercise does not cause RyR1 fragmentation in muscles of elite endurance athletes, which may explain why HIIT is less effective in this group.ryanodine receptor 1 | high-intensity exercise | skeletal muscle | Ca 2+ | reactive oxygen species

MicroRNAs (miRNA) are involved in posttranscriptional regulation of gene expression and are dysregulated during carcinogenesis. CpG island methylation of miR-137 is a common event in different cancers; however, the role of miR-137 in gastric cancer (GC) remains largely unexplored. In this study we aimed to characterize the epigenetic alterations of miR-137 in gastric carcinogenesis. We analyzed total 295 tissues including paired primary gastric cancer (T-GC) with corresponding adjacent gastric mucosa (N-GC), paired primary colorectal cancer (CRC) tissues with corresponding non-tumorous mucosa, gastric tissues from controls (N), and patients with chronic/atrophic gastritis (CG) with and without Helicobacter pylori infection. Bisulfite pyrosequencing and TaqMan RT-PCR were used to analyze miR-137 methylation and expression, respectively. Survival differences were evaluated using Kaplan-Meier analyses. miR-137 CpG island methylation was more frequent in tumorous compared to non-tumorous conditions and higher in CRC than in GC. In comparison to N-GC, miR 137 methylation level was lower in N and CG tissues, which correlates with Correas cascade. MiR-137 methylation inversely correlates with global LINE-1 methylation and miR-137 expression. miR-137 methylation was higher in intestinal type GC compared to diffuse one, and higher in antrum compared to cardia and corpus, however, miR-137 methylation was associated with worse prognosis in diffuse, but not in intestinal type of GC. The expression in colon was significantly higher compared to any gastric tissues suggesting functional difference. In summary, miR-137 methylation is a frequent event in gastrointestinal cancers which occurs early in stepwise manner during gastric carcinogenesis and inversely correlates with global methylation. © 2015 Wiley Periodicals, Inc.

Long-course preoperative chemoradiation resulted in greater statistically significant tumour downsizing and downstaging compared with short-term radiation, but there was no difference in the R0 resection rates. Similar postoperative morbidity was observed in each group.

Colorectal cancer (CRC) is one of the most common cancers worldwide with high mortality rates. MicroRNAs (miRNAs) have an established role in the development of different cancers. Single nucleotide polymorphisms (SNPs) in miRNA related genes were linked with various gastrointestinal malignancies. However, the data on association between miRNA SNPs and CRC development are inconsistent. The aim of the present study was to evaluate the association between miRNA-related gene polymorphisms (miR-27a, miR-146a, miR-196a-2, miR-492 and miR-608) and the presence of CRC in European population. Gene polymorphisms were analyzed in 621 subjects (controls: n = 428; CRC: n = 193). MiR-27a T>C (rs895819), miR-146a G>C (rs2910164), miR-196a-2 C>T (rs11614913), miR-492 G>C (rs2289030) and miR-608 C>G (rs4919510) SNPs were genotyped by RT-PCR. Overall, all genotypes and alleles of miRNA SNPs were distributed equally between control and CRC groups. We observed a tendency for miR-146a C allele to be associated with lower risk of CRC when compared to G allele, however, the difference did not reach the adjusted P-value (odds ratio (OR) = 0.68, 95% confidence interval (CI) 0.49–0.95, P = 0.025). In conclusion, gene polymorphisms of miR-27a, miR-146a, miR-196a-2, miR-492, miR-492a and miR-608 were not associated with the presence of CRC in European subjects.

Background: There still is no evidence which neoadjuvant therapy regimen for stage II-III rectal cancer is superior. The aim of this study was to compare results achieved after long-course chemoradiotherapy (CRT) with short-term radiotherapy (RT) followed by delayed surgery. Methods: A randomized trial was carried out between 2007-2013. One hundred fifty patients diagnosed with stage II-III rectal cancer were randomized into one of two neoadjuvant treatment arms: conventional chemoradiotherapy (CRT) and short-term radiotherapy (RT) followed by surgery after 6-8 weeks. Primary endpoints of this trial were downstaging and pathological complete response rate. Secondary endpoints were local recurrence rate and overall survival. Results: The pathological complete response was found in 3 (4.4%) cases after RT and 8 (11.1%) after CRT (P = 0. 112). Downstaging (stage 0 and I) was observed in 21 (30.9%) cases in RT group vs. 27 (37.5%) cases in CRT group (P = 0.409). Median follow-up time was 39.7 (range 4.9-79.7) months. 3-years overall survival (OS) was 78% in RT group vs. 82.4% in CRT group (P = 0.145), while disease-free survival (DFS) differed significantly -59% in RT group vs. 75.1% in CRT group (P = 0,022). Hazard ratio of cancer progression for RT patients was 1.93 (95% CI: 1.08-3.43) compared to CRT patients. Conclusion: Three-years disease-free survival was better in CRT group comparing with RT group with no difference in overall survival.