Long noncoding RNA TUG1 upregulates VEGFA to enhance malignant behaviors in stomach adenocarcinoma by sponging miR-29c-3p

Regulation of VEGF-A expression and VEGF-A-targeted therapy in malignant tumors

Vascular endothelial growth factor A (VEGF-A), a highly conserved dimeric glycoprotein, is a key regulatory gene and a marker molecule of angiogenesis. The upregulation of VEGF-A facilitates the process of tumor vascularization, thereby fostering the initiation and progression of malignant neoplasms. Many genes can adjust the angiogenesis of tumors by changing the expression of VEGF-A. In addition, VEGF-A also exhibits immune regulatory properties, which directly or indirectly suppresses the antitumor activity of immune cells. The emergence of VEGF-A-targeted therapy alone or in rational combinations has revolutionized the treatment of various cancers. This review discusses how diverse mechanisms in various tumors regulate VEGF-A expression to promote tumor angiogenesis and the role of VEGF-A in tumor immune microenvironment. The application of drugs targeting VEGF-A in tumor therapy is also summarized including antibody molecule drugs and traditional Chinese medicine.

TUG1 aggravates intracerebral hemorrhage injury by inhibiting angiogenesis in an miR-26a-dependent manner

Long non-coding RNA taurine-upregulated gene 1 (TUG1) plays pivotal roles in angiogenesis, an important mechanism of neural repair after intracerebral hemorrhage (ICH). However, the role of TUG1 in angiogenesis following ICH is not clear. Therefore, in this study, we investigated the role and the underlying mechanism of TUG1 in neurologic impairment and cerebral angiogenesis following ICH. The ICH rat model was established and then rats were injected with TUG1-expressing plasmid (pcDNA-TUG1) or miR-26a mimic, a critical regulator of VEGF-mediated angiogenesis. We confirmed the overexpression of TUG1 and miR-26a by qRT-PCR. The neurological deficits of ICH rats were evaluated by modified neurological severity scores. The expression of angiogenesis markers VEGF and CD31 were examined by immunohistochemistry and western blot. The interaction between TUG1 and miR-26a was determined by luciferase reporter assay. Our results showed that ICH caused a marked upregulation of TUG1 and a significant downregulation of miR-26a. TUG1 overexpression led to the deterioration of neurologic function and inhibited cerebral angiogenesis in ICH rats. In contrast, overexpression of miR-26a alleviated the neurologic damage and promoted cerebral angiogenesis in ICH rats, but these could be attenuated by TUG1 overexpression. Furthermore, TUG1 directly bound to miR-26a and inhibited its expression. Importantly, TUG1 overexpression inhibited the expression of VEGF by targeting miR-26a. In conclusion, our results indicated that TUG1 aggravated ICH-mediated injury by suppressing angiogenesis by downregulating miR-26a. This suggests a rationale for targeting TUG1/miR-26a in the therapy of ICH.

An innovative pyroptosis-related long-noncoding-RNA signature predicts the prognosis of gastric cancer via affecting immune cell infiltration landscape

Background: Gastric cancer (GC) is a worldwide popular malignant tumor. However, the survival rate of advanced GC remains low. Pyroptosis and long non-coding RNAs (lncRNAs) are important in cancer progression. Thus, we aimed to find out a pyroptosis-related lncRNAs (PRLs) signature and use it to build a practical risk model with the purpose to predict the prognosis of patients with GC. Methods: Univariate Cox regression analysis was used to identify PRLs linked to GC patient's prognosis. Subsequently, to construct a PRLs signature, the least absolute shrinkage and selection operator regression, and multivariate Cox regression analysis were used. Kaplan-Meier analysis, principal component analysis, and receiver operating characteristic curve analysis were performed to assess our novel lncRNA signature. The correlation between risk signature and clinicopathological features was also examined. Finally, the relationship of pyroptosis and immune cells were evaluated through the CIBERSORT tool and single-sample lncRNA set enrichment analysis (ssGSEA). Results: A PRLs signature comprising eight lncRNAs was discerned as a self-determining predictor of prognosis. GC patients were sub-divided into high-risk and low-risk groups via this risk-model. Stratified analysis of different clinical factors also displayed that the PRLs signature was a good prognosis factor. According to the risk score and clinical characteristics, a nomogram was established. Moreover, the difference between the groups is significance in immune cells and immune pathways. Conclusion: This study established an effective prognostic signature consist of eight PRLs in GC, and constructed an efficient nomogram model. Further, the PRLs correlated with immune cells and immune pathways.

Downregulation of miR-221-3p by LncRNA TUG1 Promoting the Healing of Closed Tibial Fractures in Mice

Objective

To probe into the effect of LncRNA TUG1 on the healing of closed tibial fracture in mice.

Methods

The closed tibial fracture model of mice was established, selecting the mouse osteoblast line MC3T3-E1, with the cells separated into four groups. The expression levels of TUG1 and miR-221-3p were determined by RT-qPCR analysis, with the targeting relationship between TUG1 and miR-221-3p authenticated by dual luciferase reporter (DLR) assay, detection of cell migration (CM) ability based on Transwell cell migration (TCM) assay, and cell proliferation (CP) acquired by cell counting kit-8 (CCK-8).

Results

Prediction results of the target gene by bioinformatics software showed that miR-221-3p had binding sites with the 3'-UTR of TUG1, and DLR assay authenticated the targeting relationship between LncRNA TUG1 and miR-221-3p. Downregulation of TUG1 inhibited osteoblast CP and CM and promoted osteoblast cell apoptosis (CA). Cell cycle analysis indicated that miR-221-3p provoked cell cycle arrest in G1 stage of MC3T3-E1 cells. The siLncRNA-NC group had higher anticyclin D1 and D3 levels than the siLncRNA TUG1 group, with a lower CA rate in the former, implying that miR-221-3p overexpression inhibited osteoblast CP and CM and LncRNA TUG1 inhibited CA. Downregulation of miR-221-3p partly reversed the retardation out of downregulating TUG1 on osteoblast CP and CM. Bcl-2 level was higher in the LncRNA TUG1 group compared to the siLncRNA TUG1 and miR-221-3p overexpression groups, with remarkably lower SDF-1 level in the miR-221-3p overexpression group than those in the control, miRNA-NC, and LncRNA TUG1 groups.

Conclusion

The downregulation of miR-221-3p by LncRNA TUG1 can promote the healing of closed tibial fractures in mice.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

The lncRNA ZNF667-AS1 Inhibits Propagation, Invasion, and Angiogenesis of Gastric Cancer by Silencing the Expression of N-Cadherin and VEGFA

Purpose. Gastric cancer is one of the most common malignancies with high mortality worldwide. It is known that long noncoding RNAs (lncRNAs) play important roles in the pathogenesis of gastric cancer. This study investigates the role of lncRNA ZNF667-AS1 in gastric cancer cells. Methods. We have applied real-time quantitative PCR (qPCR) to study the levels of ZNF667-AS1 in gastric cancer biopsies and cell lines. The effects of ZNF667-AS1 on the propagation, clonogenicity, metastasis, and angiogenesis of gastric cancer cells were evaluated by calorimetry, colony formation, cell migration, and angiogenesis assays. Western blotting was used to identify the levels of proteins involved in cancer invasion and angiogenesis signaling pathways. Result. It was found that lncRNA ZNF667-AS1 was downregulated in gastric cancer biopsies. Overexpression of ZNF667-AS1 reduced the propagation, migration, and angiogenesis of gastric cancer cells. Molecular mechanism studies displayed that the high level of lncRNA ZNF667-AS1 promoted the expression of E-cadherin and inhibited the expression of N-cadherin and VEGFA, leading to the inhibition of the proliferation, migration, and angiogenesis of gastric cancer cells. Conclusion. As a tumor suppressor gene, lncRNA ZNF667-AS1 significantly hinders the propagation, metastasis, and angiogenesis of gastric cancer cells by promoting the expression of E-cadherin and inhibiting the expression of N-cadherin and VEGFA. Therefore, lncRNA ZNF667-AS1 could play a synergistic therapeutic role by targeting tumor cells and vascular endothelial cells, which represents a new therapeutic scheme for novel therapeutics of gastric cancer.