Single-nucleotide polymorphisms and haplotype LD analysis of the 29-kb IGF2 region on chromosome 11p15.5 in the Korean population

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing

Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage.

Functional diversity of long non-coding RNAs in immune regulation

Precise and dynamic regulation of gene expression is a key feature of immunity. In recent years, rapid advances in transcriptome profiling analysis have led to recognize long non-coding RNAs (lncRNAs) as an additional layer of gene regulation context. In the immune system, lncRNAs are found to be widely expressed in immune cells including monocytes, macrophages, dendritic cells (DC), neutrophils, T cells and B cells during their development, differentiation and activation. However, the functional importance of immune-related lncRNAs is just emerging to be characterized. In this review, we discuss the up-to-date knowledge of lncRNAs in immune regulation.

Genetic variations in the transforming growth factor-beta pathway as predictors of survival in advanced non-small cell lung cancer

The magnitude of benefit is variable for advanced non-small cell lung cancer (NSCLC) patients receiving platinum-based chemotherapy. The purpose of this study is to determine whether genetic variations in the transforming growth factor-beta (TGF-β) pathway are associated with clinical outcomes in NSCLC patients receiving first-line platinum-based chemotherapy. Five hundred and ninety-eight advanced-stage NSCLC patients who received first-line platinum-based chemotherapy with or without radiotherapy were recruited at the MD Anderson Cancer Center between 1995 and 2007. DNA from blood was genotyped for 227 single nucleotide polymorphisms (SNPs) in 23 TGF-β pathway-related genes to evaluate their associations with overall survival. In individual SNP analysis, 22 variants were significantly associated with overall survival, of which the strongest associations were found for BMP2:rs235756 [hazard ratio (HR) = 1.45; 95% confidence interval (CI), 1.11-1.90] and SMAD3:rs4776342 (HR = 1.25; 95% CI, 1.06-1.47). Fifteen and 18 genetic loci displayed treatment-specific associations for chemotherapy and chemoradiation, respectively, identifying a majority of the cases who would be predicted to respond favorably to a specific treatment regimen. BMP2:rs235753 and a haplotype in SMAD3 were associated with overall survival for both treatment modalities. Cumulative effect analysis showed that multiple risk genotypes had a significant dose-dependent effect on overall survival (P(trend) = 2.44 x 10(-15)). Survival tree analysis identified subgroups of patients with dramatically different median survival times of 45.39 versus 13.55 months and 18.02 versus 5.89 months for high- and low- risk populations when treated with chemoradiation and chemotherapy, respectively. These results suggest that genetic variations in the TGF-β pathway are potential predictors of overall survival in NSCLC patients treated with platinum-based chemotherapy with or without radiation.

IGF-II gene region polymorphisms related to exertional muscle damage

We examined the association of a novel single-nucleotide polymorphism (SNP) in IGF-I (IGF-I -C1245T located in the promoter) and eight SNPs in the IGF-II gene region with indicators of muscle damage [strength loss, muscle soreness, and increases in circulating levels of creatine kinase (CK) and myoglobin] after eccentric exercise. We also examined two SNPs in the IGF binding protein-3 (IGFBP-3). The age, height, and body mass of the 151 subjects studied were 24.1 +/- 5.2 yr, 170.8 +/- 9.9 cm, and 73.3 +/- 17.0 kg, respectively. There were no significant associations of phenotypes with IGF-I. IGF-II SNP (G12655A, rs3213216) and IGFBP-3 SNP (A8618T, rs6670) were not significantly associated with any variable. The most significant finding in this study was that for men, IGF-II (C13790G, rs3213221), IGF-II (ApaI, G17200A, rs680), IGF-II antisense (IGF2AS) (G11711T, rs7924316), and IGFBP-3 (-C1592A, rs2132570) were significantly associated with muscle damage indicators. We found that men who were 1) homozygous for the rare IGF-II C13790G allele and rare allele for the ApaI (G17200A) SNP demonstrated the greatest strength loss immediately after exercise, greatest soreness, and highest postexercise serum CK activity; 2) homozygous wild type for IGF2AS (G11711T, rs7924316) had the greatest strength loss and most muscle soreness; and 3) homozygous wild type for the IGF2AS G11711T SNP showed the greatest strength loss, highest muscle soreness, and greater CK and myoglobin response to exercise. In women, fewer significant associations appeared.