Polymorphism rs7214723 in CAMKK1: a new genetic variant associated with cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of deaths worldwide. CVDs have a complex etiology due to the several factors underlying its development including environment, lifestyle, and genetics. Given the role of calcium signal transduction in several CVDs, we investigated via PCR-restriction fragment length polymorphism (RFLP) the single nucleotide polymorphism (SNP) rs7214723 within the calcium/calmodulin-dependent kinase kinase 1 (CAMKK1) gene coding for the Ca²⁺/calmodulin-dependent protein kinase kinase I. The variant rs7214723 causes E375G substitution within the kinase domain of CAMKK1. A cross-sectional study was conducted on 300 cardiac patients. RFLP-PCR technique was applied, and statistical analysis was performed to evaluate genotypic and allelic frequencies and to identify an association between SNP and risk of developing specific CVD. Genotype and allele frequencies for rs7214723 were statistically different between cardiopathic and several European reference populations. A logistic regression analysis adjusted for gender, age, diabetes, hypertension, BMI and previous history of malignancy was applied on cardiopathic genotypic data and no association was found between rs7214723 polymorphism and risk of developing specific coronary artery disease (CAD) and aortic stenosis (AS). These results suggest the potential role of rs7214723 in CVD susceptibility as a possible genetic biomarker.     

A genetic variant in LINGO2 contributes to the risk of gestational diabetes mellitus in a Chinese population

Genome-wide association studies (GWASs) showed that three single nucleotide polymorphisms (SNPs; rs10968576, rs1412239, and rs824248) in the leucine-rich repeat and Ig domain containing 2 (LINGO2) were associated with obesity or type 2 diabetes (T2D). We aimed to determine the influence of the LINGO2 variants on the gestational diabetes mellitus (GDM) risk. Thus, we performed a case–control study including 964 GDM cases and 1,021 controls to test the associations between the three LINGO2 variants (rs10968576, rs1412239, and rs824248) and susceptibility to GDM. Logistic regression analyses showed no significant association between LINGO2 variations (rs10968576 and rs1412239) and GDM susceptibility, but we observed that LINGO2 rs824248 A > T was significantly associated with an increased risk of GDM using the dominant model (TT/AT vs. AA: adjusted odds ratio [OR] = 1.26, 95% confidence interval [CI] = 1.05–1.51; p = 0.012) and the additive model (TT vs. AT vs. AA: adjusted OR = 1.16, 95% CI = 1.03–1.31; p = 0.016). In the additive model, a stronger risk effect of rs824248 was observed among obese women (prepregnancy body mass index [BMI] > 22 kg/m², adjusted OR = 1.34, 95% CI = 1.12–1.59) compared with that in lean women (prepregnancy BMI ≤ 22 kg/m², adjusted OR = 1.0², 95% CI = 0.86–1.21; p = 0.029 for heterogeneity test). Further interactive analyses also detected a significant multiplicative interaction between rs824248 and prepregnancy BMI for the risk of GDM (p = 0.041). These findings indicate that LINGO2 rs824248 may serve as a susceptibility marker for GDM in Chinese females.     

The common rs9939609 gene variant of the fat mass- and obesity-associated gene FTO is related to fat cell lipolysis

We investigated the rs9939609 single nucleotide polymorphism of the FTO gene in relation to fat cell function and adipose tissue gene expression in 306 healthy women with a wide range in body mass index (18-53 kg/m(2)). Subcutaneous adipose tissue biopsies were taken for fat cell metabolism studies and in a subgroup (n = 90) for gene expression analyses. In homozygous carriers of the T-allele, the in vitro basal (spontaneous) adipocyte glycerol release was increased by 22% (P = 0.007) and the in vivo plasma glycerol level was increased by approximately 30% (P = 0.037) compared with carriers of the A allele. In contrast, there were no genotype effects on catecholamine-stimulated lipolysis or basal or insulin-induced lipogenesis. We found no difference between genotypes for adipose tissue mRNA levels of FTO, hormone-sensitive lipase, adipose triglyceride lipase, perilipin, or CGI-58. Finally, the adipose tissue level of FTO mRNA was increased in obesity (P = 0.002), was similar in subcutaneous and omental adipose tissue, was higher in fat cells than in fat tissue (P = 0.0007), and was induced at an early stage in the differentiation process (P = 0.004). These data suggest a role of the FTO gene in fat cell lipolysis, which may be important in explaining why the gene is implicated in body weight regulation.     

A genetic variant in CDKN2A/2B locus was associated with poor prognosis in patients with esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is among the leading causes of cancer related death. Despite of extensive efforts in identifying valid cancer prognostic biomarkers, only a very small number of markers have been identified. Several genetic variants in the 9p21 region have been identified that are associated with the risk of multiple cancers. Here, we explored the association of two genetic variants in the 9p21 region, CDKN2A/B, rs10811661, and rs1333049 for the first time in 273 subjects with, or without ESCC. We observed that the patients with ESCC had a higher frequency of a TT genotype for rs10811661 than individuals in the control group, and this polymorphism was also associated with tumor size. Moreover, a CC genotype for the rs1333049 polymorphism was associated with a reduced overall survival (OS) of patients with ESCC. In particular, patients with a CC (rs1333049) genotype had a significantly shorter OS (CC genotype: 34.5 ± 8.9 months vs. CG+GG: 47.7 ± 5.9 months; p value = 0.03). We have also shown the association of a novel genetic variant in CDKN2B gene with clinical outcome of patients with ESCC. Further investigations are warranted in a larger population to explore the value of emerging markers as a risk stratification marker in ESCC.     

LncRNA FOXD2‐AS1 as a competitive endogenous RNA against miR‐150‐5p reverses resistance to sorafenib in hepatocellular carcinoma

The current study elucidated the role of a long non‐coding RNA (lncRNA), FOXD2‐AS1, in the pathogenesis of hepatocellular carcinoma (HCC) and the regulatory mechanism underlying FOXD2‐AS1/miR‐150‐5p/transmembrane protein 9 (TMEM9) signalling in HCC. Microarray analysis was used for preliminary screening of candidate lncRNAs in HCC tissues. qRT‐PCR and Western blot analyses were used to detect the expression of FOXD2‐AS1. Cell proliferation assays, luciferase assay and RNA immunoprecipitation were performed to examine the mechanism by which FOXD2‐AS1 mediates sorafenib resistance in HCC cells. FOXD2‐AS1 and TMEM9 were significantly decreased and miR‐150‐5p was increased in SR‐HepG2 and SR‐HUH7 cells compared with control parental cells. Overexpression of FOXD2‐AS1 increased TMEM9 expression and overcame the resistance of SR‐HepG2 and SR‐HUH7 cells. Conversely, knockdown of FOXD2‐AS1 decreased TMEM9 expression and increased the sensitivity of HepG2 and Huh7 cells to sorafenib. Our data also demonstrated that FOXD2‐AS1 functioned as a sponge for miR‐150‐5p to modulate TMEM9 expression. Taken together, our findings revealed that FOXD2‐AS1 is an important regulator of TMEM9 and contributed to sorafenib resistance. Thus, FOXD2‐AS1 may serve as a therapeutic target against sorafenib resistance in HCC.     

Construction of competitive endogenous RNA network reveals regulatory role of long non‐coding RNAs in type 2 diabetes mellitus

Increasing epidemic of type 2 diabetes mellitus (T2DM) and its comorbidities makes it urgent to understand the pathogenesis and regulatory mechanism. However, little is known about the regulatory role of lncRNAs in diabetes. Here, we constructed a T2DM‐related competitive endogenous RNA (ceRNA) network (DMCN) to explore biological function of lncRNAs during the development of diabetes mellitus. This network contained 351 nodes including 98 mRNAs, 86 microRNAs and 167 lncRNAs. Functional analysis showed that the mRNAs in DMCN were annotated into some diabetes‐related pathways. Furthermore, mTOR‐centred subnetwork was extracted and ncRNA‐involved mTOR pathway was established. Finally, we validated that NEAT1 was potentially communicated with mTOR signalling target protein mLST8 via the association with miR‐181b. These findings provide significant insight into lncRNA regulatory network in T2DM.     

Association of a P2RX7 gene missense variant with brachycephalic dog breeds

Missense variants are associated with various phenotypic traits and disorders in dogs. The canine P2RX7 gene, coding the ATP-gated P2X7 receptor ion channel, contains four known missense variants. The current study aimed to examine the presence of these variants in a random sample of pedigree and mixed-pedigree dogs. Exons 3, 8, 11 and 13 of the P2RX7 gene, encoding these four respective variants, in 65 dogs were assessed by Sanger sequencing and combined with existing sequencing data from another 69 dogs. The distribution of these variants was then evaluated in all 134 dogs combined and separately within individual breeds including 35 different pure breeds. The rs23314713 (p.Phe103Leu) and rs23315462 (p.Pro452Ser) variants were present in 47 and 40% of all dogs studied respectively, with the rs23314713 variant associated with brachycephalic breeds. Among pedigree dogs, the rs23314713 and rs23315462 variants were associated with brachycephalic and non-brachycephalic breeds respectively. The rs851148233 (p.Arg270Cys) and rs850760787 (p.Arg365Gln) variants were present only in dogs of Cocker Spaniel and Labrador Retriever pedigrees respectively. No other missense variants were found in exons 3, 8, 11 and 13 of the P2RX7 gene within the dogs. In conclusion, the rs23314713 and rs23315462 missense variants of the P2RX7 gene are present in a large proportion of dogs, with the rs23314713 variant associated with a number of brachycephalic breeds. However, the association of this variant with dogs of bulldog ancestry, not brachycephaly per se, cannot be excluded.     

Association between FABP2 Ala54Thr polymorphisms and type 2 diabetes mellitus risk: a HuGE Review and Meta‐Analysis

Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians.     

lncRNA MIR4435‐2HG promoted clear cell renal cell carcinoma malignant progression via miR‐513a‐5p/KLF6 axis

Long non‐coding RNAs (lncRNAs) take various biological effects in clear cell renal cell carcinoma (ccRCC) mostly through sponging with microRNAs (miRNAs). lncRNA MIR4435‐2HG is found to promote tumour progression in gastric cancer, glioblastoma and hepatocellular carcinoma. However, the role of lncRNA MIR4435‐2HG in ccRCC progression remains unknown. The purpose of this research was to investigate the potential molecular mechanism of lncRNA MIR4435‐2HG regarding the regulation of ccRCC initiation and progression. In this study, we found the up‐regulation of MIR4435‐2HG in ccRCC tissues and cell lines. Functionally, overexpression of MIR4435‐2HG promoted the proliferation as well as the metastasis in ccRCC cell lines, whereas knockdown of MIR4435‐2HG inhibited the above changes. Then, bioinformatic analysis and luciferase reporter assays confirmed the negative regulation effect of MIR4435‐2HG on miR‐513a‐5p. And further investigations showed that KLF6, which collected from the intersection of databases, was the potential conjugated mRNAs of miR‐513a‐5p. Finally, the rescue experiments revealed the relation among MIR4435‐2HG and KLF6, which showed that KLF6 could reverse the promoting effect of MIR4435‐2HG on ccRCC in vitro and in vivo. Therefore, our findings provided insight into the mechanisms of MIR4435‐2HG in ccRCC and revealed an alternative target for the clinical diagnosis and treatment of ccRCC.