LncRNA HOTAIR regulates the expression of E-cadherin to affect nasopharyngeal carcinoma progression by recruiting histone methylase EZH2 to mediate H3K27 trimethylation.

BACKGROUND/AIM: There has been increasing evidence for the function of long non-coding RNA (lncRNA) in nasopharyngeal carcinoma (NPC). We aim to delve into the position of lncRNA HOX antisense intergenic RNA (HOTAIR), together with enhancer of zeste homolog 2 (EZH2), E-cadherin and trimethylation of lysine 27 on histone H3 (H3K27me3) in NPC. METHODS: HOTAIR, EZH2, and E-cadherin expression in NPC tissues and cells were tested. NPC cell biological functions were examined through gain-of and loss-of function assays. The mechanism of lncRNA HOTAIR/E-cadherin/EZH2/H3K27 axis in NPC was decoded. RESULTS: LncRNA HOTAIR and EZH2 were highly expressed in NPC, and E-cadherin was lowly expressed. Down-regulation of HOTAIR or EZH2 inhibited NPC cell progression and tumor growth. HOTAIR recruited histone methylase EZH2 to mediate trimethylation of H3K27 and regulated E-cadherin expression. CONCLUSION: HOTAIR inhibits E-cadherin by stimulating the trimethylation of H3K27 to promote NPC cell progression through recruiting histone methylase EZH2.

Association of LncRNA-GAS5 gene polymorphisms and PBMC LncRNA-GAS5 level with risk of systemic lupus erythematosus in Chinese population.

Growth arrest-specific 5 (GAS5) is a kind of long non-coding RNAs (lncRNAs). Previous studies showed that down-regulation of LncRNA-GAS5 was involved in the development of systemic lupus erythematosus (SLE). However, the regulatory mechanism of down-expressed LncRNA-GAS5 in SLE remains obscure. In this study, we aimed to investigate the association of LncRNA-GAS5 polymorphism with SLE risk. And further explore how LncRNA-GAS5 is involved in the occurrence of SLE. Here, we evaluated the relationship between the risk for the development of SLE and the 5-base pair (AGGCA/-) insertion/deletion (I/D) polymorphism (rs145204276) in the LncRNA-GAS5 promoter region. A custom 36-Plex SNPscan kit was used for genotyping the LncRNA-GAS5 polymorphisms. The LncRNA-GAS5 and miR-21 target prediction was performed using bioinformatics software. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR) were performed to assess GAS5 and miR-21 mRNA expression and PTEN protein expression. The results revealed that rs145204276 resulted in a decreased risk of SLE (DD genotypes vs II genotypes: adjusted OR = 0.538, 95% CI, 0.30-0.97, P = .039; ID genotypes vs II genotypes: adjusted OR = 0.641, 95% CI, 0.46-0.89, P = .007; ID/DD genotypes vs II genotypes: adjusted OR = 0.621, 95% CI, 0.46-0.84, P = .002; D alleles vs I alleles: adjusted OR = 0.680, 95% CI, 0.53-0.87, P = .002). A reduced incidence of renal disorders in SLE was found to be related to ID/DD genotypes and D alleles (ID/DD genotypes vs II genotypes: OR = 0.57, 95% CI, 0.36-0.92, P = .020; D alleles vs I alleles: OR = 0.63, 95% CI, 0.43-0.93, P = .019). However, no significant association of rs2235095, rs6790, rs2067079 and rs1951625 polymorphisms with SLE risk was observed (P > .05). Additionally, haplotype analysis showed that a decreased SLE risk resulted from the A-A-C-G-D haplotype (OR = 0.67, 95% CI, 0.49-0.91, P = .010). Also, patients in the SLE group showed a down-regulated expression of LncRNA-GAS5 and PTEN than the healthy volunteers; however, patients with rs145204276 ID/DD genotypes showed up-regulated expression of LncRNA-GAS5 and PTEN compared with patients carrying the II genotype. Furthermore, the miR-21 levels were considerably up-regulated in the SLE group than the healthy volunteers, and patients with rs145204276 ID/DD genotype had lower miR-21 levels than the ones with the II genotype. Thus, we found that the LncRNA-GAS5/miR-21/PTEN signalling pathway was involved in the development of SLE, where LncRNA-GAS5 acted as an miR-21 target, and miR-21 regulated the expression of PTEN. These findings indicated that the rs145204276 ID/DD genotypes in the LncRNA-GAS5 gene promoter region may be protected against SLE by up-regulating the expression of LncRNA-GAS5, which consecutively regulated miR-21 and PTEN levels.

Association between polymorphisms in the promoter region of miR-17-92 cluster and systemic lupus erythematosus in a Chinese population.

The aim of this study was to investigate the association of genetic polymorphisms in the promoter region of miR-17-92 with systemic lupus erythematosus (SLE). The gene polymorphism was analysed using SNaPshot in 312 SLE patients and 396 controls. Relative expression of miR-17-92 was measured by quantitative real-time PCR. Association was found between rs9515692 and a decreased risk of SLE (CT vs CC: OR = 0.65, 95%CI, 0.46-0.92, P = .014; CT+TT vs CC: OR = 0.64, 95%CI, 0.46-0.90, P = .009; T vs C: OR = 0.69, 95%CI, 0.52-0.92, P = .010, respectively). Haplotype analysis showed that C-G-G, C-A-A haplotypes were associated with an increased SLE risk (OR=4.46, 95%CI, 2.17-9.17, P < 0.001; OR=2.33, 95%CI, 1.44-3.76, P < 0.001, respectively). T allele and CT+TT genotypes in rs9515692 were associated with decreased risk of anti-dsDNA in SLE (CT+TT vs CC: OR = 0.42, 95%CI = 0.24-0.72, P = .002; T vs A: OR = 0.49, 95%CI = 0.31-0.79, P = .003). Moreover, rs9515692 CT+TT genotypes had a higher level of miR-17 as compared to CC genotype (P = .017). These findings suggest that the rs9515692 CT+TT genotypes were a protective factor for the susceptibility of SLE, probably by increasing the expression of miR-17.

Effects of Lycium barbarum Polysaccharide on Endoplasmic Reticulum Stress and Oxidative Stress in Obese Mice.

BACKGROUND: The incidence of obesity-associated decline in male fertility has increased over the years. Lycium barbarum polysaccharide (LBP), a natural plant polysaccharide extracted from the Chinese herb L. barbarum has shown promising therapeutic effects in overcoming the same. AIM: This study aimed to investigate the protective effect of LBP on the testes of obese mice. METHODS: Following administration of LBP to high-fat diet-induced obese mice for 35 days, serum, sperm, and testis samples were obtained for subsequent experiments. Biochemical analysis and sex hormone content determination were performed to observe changes in glycolipid metabolism and testosterone levels, respectively, in the blood. Hematoxylin and eosin staining were carried out to assess the pathological changes in the testicular tissue. Oxidative stress levels were detected using enzyme-linked immunosorbent assay and expression levels of endoplasmic reticulum stress markers were determined using western blot in the testicular tissue. RESULTS: Our results suggested that LBP reduced glucose levels and insulin resistance, increased testosterone levels and insulin sensitivity, and decreased testicular oxidative stress and pathological damage in obese mice. In addition, LBP down-regulated the expression of p-eIF2α, GRP78, and CHOP in the testicular tissues of obese mice. CONCLUSION: Our results show that LBP is a potential novel drug for preventing male infertility caused by obesity.

A Genetic Variant of miR-34a Contributes to Susceptibility of Ischemic Stroke Among Chinese Population.

miRNAs are small non-coding RNAs modulating gene expression, and variants in miRNA genes are involved in the pathogenesis of ischemic stroke (IS). However, the effect of miR-34a polymorphisms on IS susceptibility has rarely been reported. In the present study, we investigated the association between rs12128240, rs2666433, and rs6577555 of the miR-34a gene and IS susceptibility. Snapshot assay was used to detect miR-34a polymorphisms in 548 IS patients and 560 controls. Relative expression of miR-34a was measured by quantitative real-time PCR. We found that rs2666433 was associated with a significantly increased risk of IS (AA vs. GG: OR = 1.61, 95% CI = 1.05-2.52, P = 0.031; AA vs. GG+GA: OR = 1.58, 95% CI = 1.05-2.45, P = 0.026). For the IS subtypes, rs2666433 was associated with large artery atherosclerosis (AA vs. GG: OR = 2.09, 95% CI = 1.16-3.51, P = 0.007; AA vs. GG+GA: OR = 2.02, 95% CI = 1.15-3.33, P = 0.007; A vs. G: OR = 1.36, 95% CI = 1.07-1.81, P = 0.021). Additionally, the level of miR-34a was significantly up-regulated in IS patients compared to the controls (P < 0.001), and patients with rs2666433 AA genotype had a higher level of miR-34a than those with GG+GA genotypes (P < 0.001). Furthermore, increased level of homocysteine was observed in IS patients compared to the controls (P < 0.001), especially in patients carrying the rs2666433AA genotype compared to those carrying the rs2666433 GG+GA genotypes (P < 0.001). However, no significant association between rs12128240 or rs6577555 and IS was found. Collectively, our study found the association between miR-34a polymorphisms and the risk of IS among the Chinese population. The results may provide an explanation for etiology of IS and a potential biomarker or therapeutic target for IS. HIGHLIGHTS-MiR-34a rs2666433 polymorphism was associated with an increased risk of ischemic stroke.-The level of miR-34a was significantly up-regulated in ischemic stroke patients compared with controls, and patients with rs2666433 AA genotype had a higher level miR-34a than those with GG+GA genotypes.-Furthermore, increased level of homocysteine was showed in IS patients compared to controls, and in patients carrying the rs2666433AA compared to those carrying the rs2666433 GG+GA.