STAT3-induced lncRNA HAGLROS overexpression contributes to the malignant progression of gastric cancer cells via mTOR signal-mediated inhibition of autophagy.

BACKGROUND: Long noncoding RNAs (lncRNAs) are an important class of functional regulators involved in human cancers development, including gastric cancer (GC). Studying aberrantly expressed lncRNAs may provide us with new insights into the occurrence and development of gastric cancer by acting as oncogenes or tumor suppressors. In this study, we aim to examine the expression pattern of lncRNA HAGLROS in GC and its clinical significance as well as its biological role in tumor progression. METHODS: Bioinformatics analysis and qRT-PCR were performed to detect the relative expression of HAGLROS in GC tissues and cell lines. Gain or loss of function approaches were used to investigate the biological functions of HAGLROS. The effect of HAGLROS on proliferation was evaluated by MTT, colony formation assay and nude mouse xenograft model. Wound healing and Transwell assays were used to study the invasion and migration of GC cells. FISH, RIP, RNA-seq, Luciferase report assays, RNA pulldown and Western blot were fulfilled to measure molecular mechanisms. Results are shown as means ± S.D. and differences were tested for significance using Student's t-test (two-tailed). RESULTS: We screened out HAGLROS, whose expression was significantly increased and correlated with outcomes of GC patients by publicly available lncRNAs expression profiling and integrating analyses. Exogenous down-regulation of HAGLROS expression significantly suppressed the cell proliferation, invasion and migration. Mechanistic investigations showed that HAGLROS was a direct target of transcriptional factor STAT3. Moreover, HAGLROS knockdown decreased mTOR expression and increased autophagy-related genes ATG9A and ATG9B expression. Further investigation showed that HAGLROS regulated mTOR signals in two manners. In the one hand, HAGLROS competitively sponged miR-100-5p to increase mTOR expression by antagonizing miR-100-5p-mediated mTOR mRNA inhibition. On the other hand, HAGLROS interacted with mTORC1 components to activate mTORC1 signaling pathway which was known to be an important negative signal of autophagy. Here activation of mTORC1 signaling pathway by HAGLROS inhibited autophagy, thereby promoted excessive proliferation and maintained the malignant phenotype of GC cells. CONCLUSION: The present study demonstrates that HAGLROS overexpression contributes to GC development and poor prognosis and will be a target for GC therapy and further develop as a potential prognostic biomarker.

Association of TERT rs2736098 polymorphism with cancer risk: a meta-analysis.

Studies have reported an association between the TERT rs2736098 single nucleotide polymorphism (SNP) and cancer susceptibility, but the results remain inconclusive. Toprovide a more precise estimation of the relationship, a meta-analysis of 8 published studies including 8,070 cases and 10,239 controls was performed. Stratification by sample size, genotyping method, source of controls and ethnicity were used to explore the source of heterogeneity. In the overall analysis, no significant association was found between the TERT rs2736098 polymorphism and cancer risk. However, the result showed the rs2736098 was significantly associated with an increased cancer risk and the heterogeneity was effectively decreased for homozygote comparison by removal of two studies: OR = 1.337 (95% CI = 1.183-1.511; Pheterogeneity = 0.087). In the subgroup analysis by ethnicity, a significantly increased risk of cancers was found among Asians (OR = 1.413, 95% CI = 1.187-1.683 for AA versus GG). Our meta-analysis did not show that the TERT rs2736098 plays an important role in cancer risk. More studies with larger sample size and well-matched controls are needed to confirm the findings.

Parkinson's disease in China.

Paralysis agitans was first documented in 1817 by James Parkinson, and therefore the syndrome was named Parkinson's disease (PD). In fact, as early as more than 2000 years ago, the clinical manifestations of this disease have been described in Chinese medicine classics, such as the "Huangdi Neijing (Yellow Emperor's Internal Classic)" and "Zhong Zang Jing (Hua's Zhong Zang Classic)." In recent years, especially in the past 30 years after reform and opening-up, PD has drawn a lot of attention by Chinese scholars. Although great progress in the studies of PD has been made in recent years, the gap between China and western countries still exists. In this review, we concentrate on the main progress made in epidemic characteristics, etiology, diagnosis and management of PD in China.

Favorable effects of VEGF gene transfer on a rat model of Parkinson disease using adeno-associated viral vectors.

Vascular endothelial growth factor (VEGF) is a specific angiogenic peptide, which has been identified to play a critical role in neurodegeneration, and has beneficial effects on neurons. In this study, we investigated whether neurodegeneration in a rat model of Parkinson disease could be prevented by VEGF gene transfer mediated by adeno-associated virus (AAV) vectors. Our results demonstrated that a single injection of a VEGF-expressing AAV vector into striatum improved the rotational behavior of rat Parkinson disease models, and promoted the survival of dopaminergic neurons and fibers. Meanwhile, AAV-VEGF injection significantly increased the reactive astrocytes and the levels of glial cell line-derived neurotrophic factor in striatum, but did not induce extra angiogenesis and remarkable disorder of blood-brain barrier. We thus conclude that intrastriatal delivery of VEGF gene mediated by AAV has favorable effects on the dopaminergic neurons in a rat Parkinson disease model.

[Adenovirus mediated vascular endothelial growth factor gene transfer protects dopaminergic neurons in Parkinson's disease: experiment with rats].

OBJECTIVE: To evaluate the protective effect of adenovirus mediated vascular endothelial growth factor 165 (VEGF165) gene transfer on dopaminergic neurons in Parkinson disease (PD). METHODS: Adenovirus vector coding VEGF165 (Ad-VEGF165) was injected into the striate bodies of 16 SD rats, and adenovirus Ad-LacZ was injected into 25 rats and phosphate-buffered saline (PBS) was injected into 16 rats as controls. Then 6-hydroxydopamine (6-OHDA) was injected to establish PD model. X-gal staining was used to detect the expression of the report gene LacZ in the brain of the Ad-LacZ group 3 d, 2 w, and 6 w after injection, 3 rats in each time point. RT-PCR was used to detect the VEGF165 mRNA expression in the striate body of the rats of the 3 groups 2 weeks after injection, 3 rats for each group. Western blotting was performed to check the protein expression of VEGF165 in the striate bodies of the rats of the 3 groups 2 weeks after injection, 3 rats for each group. A certain numbers of rats in each group underwent rotational behavior analysis 1, 2, and 6 weeks after the 6-OHDA injection. Immunohistochemistry was used to examine the number of tyrosine hydroxylase (TH) positive neuron, density of TH-positive fiber in striate body and black substance, laminin-positive vessel density, and glial fibrillary acidic protein (GFAP) positive glial cells. High performance liquid chromatography-electric-chemical discharge (HPLC-ECD) was performed to detect the contents of dopamine (DA) and its metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum. RESULTS: Beta-gal was expressed in the striate bodies of all Ad-LacZ transfected rats, showing the successful transfection of LacZ gene. The mRNA expression and protein expression of VEGF165 in the striate body were significantly higher in the Ad-VEGF165 group than in the other 2 groups. The apomorphine-induced rotation number in the Ad-VEGF165 group was 8.3 turns/min +/- 8.7 turns/min 1 week after the transfection, then gradually decreased, and became 5.0 turns/min +/- 4.4 turns/min 6 weeks after. The rotation numbers of the Ad-LacZ and PBS group were 14.7 turns/min +/- 11.2 turns/min and 13.9 turns/min +/- 8.3 turns/min respectively 1 week after the injection, then increased gradually, and became 20.2 turns/min +/- 13.6 turns/min and 21.8 turns/min +/- 11.8 turns/min respectively 6 weeks later, all significantly higher than those of the Ad-LacZ group (all P < 0.01). The ratios of TH-positive cells in the black substance in the transfected side was 0.42 +/- 0.11, and the density of fibers in the striate body of the transfected side to that of the contralateral side was 0.56 +/- 0.10 in the Ad-VEGF165 group, both significantly higher than those of the Ad-LacZ group (0.20 +/- 0.10 and 0.28 +/- 0.09) and PBS group (0.22 +/- 0.13 and 0.24 +/- 0.08), (all P < 0.01). The ratio of laminin-positive vessel density of the transfected side to that of the contralateral side in the Ad-VEGF165 group was 2.09 +/- 0.42, and the ratio of GFAP-positive glial cells of the striate body of the transfected side to that of the contralateral side was 2.77 +/- 1.21 in the Ad-VEGF165 group, both significantly higher than those in the Ad-LacZ group (1.01 +/- 0.16 and 1.64 +/- 0.28) and the PBS group (1.04 +/- 0.09 and 1.56 +/- 0.62) (P < 0.01 and 0.05). HPLC-ECD showed that the contents of DA, HAV, and DOPAC of the striate body at the destroyed side in the Ad-VEGF165 group were all significantly higher than those in the other 2 groups (all P < 0.01). The ratios to the DA, DOPAC, and HVA of the destroyed side striate body to those of the contralateral side in the Ad-VEGF165 group was 0.35 +/- 0.11, 0.46 +/- 0.09, and 0.38 +/- 0.09 respectively, all significantly higher than those in the Ad-LacZ group (0.17 +/- 0.15, 0.21 +/- 0.07, and 0.16 +/- 0.05) and PBS group (0.19 +/- 0.06, 0.20 +/- 0.09, 0.14 +/- 0.03) (all P < 0.01). CONCLUSION: Gene transfer of Ad-VEGF165 has a protective effect on the dopaminergic neurons of PD. The proliferation of vessels and glial cells induced by VEGF may involve in the process of neuroprotection to the dopaminergic neurons of PD.