Long non-coding RNA OIP5-AS1 promotes cell proliferation and aerobic glycolysis in gastric cancer through sponging miR-186

Construction of a novel disulfidptosis and cuproptosis-related lncRNA signature for predicting the clinical outcome and immune response in stomach adenocarcinoma

BACKGROUND

Disulfidptosis, a newly discovered form of cell death resulting from disulfide stress, remains unclear in its role in stomach adenocarcinoma (STAD). This study aimed to establish a novel disulfidptosis and cuproptosis-related lncRNAs (DCRLs) signature for STAD.

METHODS

We sourced RNA-seq data for STAD from the The Cancer Genome Atlas (TCGA) repository. STAD samples underwent nonnegative matrix factorization (NMF) clustering to identify distinct molecular subgroups, followed by Lasso-Cox regression to construct a prognostic model for DCRLs. Subsequently, the model's clinical predictive capacity was evaluated using a nomogram. The expression of risk lncRNAs was validated via quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

The samples were classified into three molecular subtypes based on DCRLs, with the C1 subtype demonstrating the worst prognosis. We identified four independent prognostic lncRNAs (AC016394.2, NUTM2A-AS1, OIP5-AS1, and LIMS1-AS1) and constructed a prognostic risk model. Survival analysis revealed that high-risk patients had a poorer prognosis. The model's risk score was strongly correlated with the tumor mutational burden (TMB), microsatellite instability (MSI), immune subtypes, and tumor-infiltrating immune cells (TIICs) in the tumor microenvironment (TME). Analysis utilizing the Tumor Immune Dysfunction and Exclusion (TIDE) revealed a higher risk of tumor immune evasion among high-risk patients. Moreover, the expression levels of four risk lncRNAs were higher in the majority of gastric cancer cell lines compared to normal cell lines.

CONCLUSION

Our study establishes a risk model that effectively predicts clinical outcomes and immune response in STAD.

LncRNA OIP5-AS1 Targets the miR-140-5p/UBR5 Cascade to Promote the Development of Gastric Cancer

Gastric cancer (GC) is a malignant tumor with the highest incidence among all kinds of malignant tumors in China. Long noncoding RNAs (LncRNAs) have been reported to act as microRNA (miRNAs) sponges and thus play key roles in biological processes and pathogenesis. Thus, this study aimed to investigate the functional effects and the regulatory mechanism of lncRNA opa interacting protein 5-antisense 1 (OIP5-AS1) in gastric cancer cells. The expression of OIP5-AS1, miR-140-5p, Ubiquitin protein ligase E3 component n-recognin 5 (UBR5) was detected using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration, and invasion were assessed using Cell-Counting Kit-8 (CCK-8), Flow cytometry, and Transwell assays. UBR5 protein level was detected by Western blot. Binding between miR-140-5p and OIP5-AS1 or UBR5 was predicted by Starbasev2.0 and TargetScan, and verified using Dual-luciferase reporter assays and RNA pull-down assay. A xenograft mice model was used to evaluate the effects of OIP5-AS1 on tumor growth in vivo. OIP5-AS1 was upregulated in GC cancer and cells. OIP5-AS1 knockdown inhibited cell proliferation, migration, invasion, but induced cell apoptosis in GC. In mechanism, OIP5-AS1 might serve as a sponge for miR-140-5p to enhance UBR5 expression. Moreover, overexpression of miR-140-5p or UBR5 partly reversed the effects of OIP5-AS1 depletion on the progression of GC cells. Furthermore, OIP5-AS1 depletion also suppressed tumor growth in vivo. OIP5-AS1 silencing might suppress proliferation, migration, invasion, and induced apoptosis in GC cells by regulating the miR-140-5p/UBR5 axis.

N6-methyladenosine modification of OIP5-AS1 promotes glycolysis, tumorigenesis, and metastasis of gastric cancer by inhibiting Trim21-mediated hnRNPA1 ubiquitination and degradation

BACKGROUND

Opa-interacting protein 5 antisense transcript 1 (OIP5-AS1) has been demonstrated to play vital roles in development and progression of tumors such as gastric cancer (GC). However, the detailed molecular mechanism of OIP5-AS1 has not been completely elucidated. Our study aimed to investigate the role and the epigenetic regulation mechanism of OIP5-AS1 in GC.

METHODS

OIP5-AS1 expression in GC tissues was detected by RT-qPCR. Loss- and gain-of-function experiments were conducted to assess the biological function of OIP5-AS1 in vitro and in vivo. The interaction of OIP5-AS1 with insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) or heterogeneous nuclear nucleoprotein A1 (hnRNPA1) was verified by bioinformatics analysis, RNA pull-down assays, and RNA immunoprecipitation assays.

RESULTS

In this study, we identified that OIP5-AS1 is specifically overexpressed in GC tumor tissues and cell lines and correlated with a poor prognosis. The loss of OIP5-AS1 suppressed the proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and glycolysis of GC cells, but the ectopic expression of OIP5-AS1 had the opposite impact. Meanwhile, knockdown of OIP5-AS1 inhibited tumor growth in patient-derived xenograft models, as well as repressed tumor metastasis. Mechanistically, IGF2BP3 could bind to OIP5-AS1 by N6-methyladenosine (m6A) modification sites on OIP5-AS1, thereby stabilizing OIP5-AS1. Moreover, OIP5-AS1 prevented Trim21-mediated ubiquitination and degradation of hnRNPA1, stabilizing hnRNPA1 protein and promoting the malignant progression of GC by regulating PKM2 signaling pathway.

CONCLUSIONS

In conclusion, this study highlighted that OIP5-AS1 is an oncogenic m6A-modified long non-coding RNA (lncRNA) in GC and that IGF2BP3/OIP5-AS1/hnRNPA1 axis may provide a potential diagnostic or prognostic target for GC.

circRPS19 affects HK2‑mediated aerobic glycolysis and cell viability via the miR‑125a‑5p/USP7 pathway in gastric cancer

Despite advances in diagnosis and treatment, gastric cancer (GC) remains a refractory disease, which limits overall survival. Therefore, it is key to identify novel targets to develop more effective and precise treatment. Circular RNAs (circRNAs) serve essential roles in the process of various human cancers. Through analyzing GSE83521 dataset, the present study identified a novel circRNA derived from ribosomal protein S19 (circRPS19), which was considered a potential treatment target for GC. Results of RT‑qPCR indicated that circRPS19 was upregulated in GC compared with normal gastric epithelial cells. Loss‑of function assays revealed that silencing of circRPS19 suppressed proliferation and aerobic glycolysis but increased apoptosis of GC cells. circRPS19 upregulated ubiquitin‑specific processing protease 7 (USP7) expression by sponging microRNA (miR)‑125a‑5p. circRPS19 stabilized hexokinase 2 (HK2) protein by USP7‑mediated deubiquitination of HK2. In vivo experiments confirmed that circRPS19 promoted GC progression and aerobic glycolysis. Taken together, circRPS19 induced aerobic glycolysis of GC cells by stabilizing HK2 protein via the miR‑125a‑5p/USP7 axis and thus promoting the progression of GC. These findings suggested that circRPS19 served a critical role in the progression of GC and may be a novel therapeutic target for GC.

lncRNA GAPLINC regulates vascular endothelial cell apoptosis in atherosclerosis

Introduction

In this study, we investigated the role of the long non-coding RNA GAPLINC in atherosclerosis under oxidized low-density lipoprotein (ox-LDL) treatment.

Material and methods

We utilized ox-LDL exposed human aortic endothelial cells as an in-vitro model. The expression level of GAPLINC was quantified by qPCR in different times and concentrations of ox-LDL treatment conditions. Cell apoptosis rate and cell cycle profiles were assessed by flow cytometry and TUNEL assay. The target association was confirmed using a luciferase reporter assay and Western blot.

Results

We found that GAPLINC expression was induced by ox-LDL treatment, but cell proliferation ability was significantly inhibited. We further confirmed that overexpressing of lncRNA GAPLINC in ox-LDL-exposed HAECs decreased cell proliferation by increasing cell apoptosis and arresting cell cycle in G2/M and S phase. Importantly, the detailed mechanistic analysis elucidated that LncRNA GAPLINC acts as a decoy to sequester miR-183-5p to prevent it from binding to target PDCD4. MiR-183-5p targets GAPLINC, and PDCD4 is a downstream target of miR-183-5p, and the cellular effects of this direct interaction were confirmed by a rescue assay experiment.

Conclusions

The present study demonstrates that upregulation of lncRNA GAPLINC represses the binding of miR-183-5p to the PDCD4 promoter region and then promotes PDCD4 expression, thereby inducing cell apoptosis and suppressing endothelial cell proliferation.

The role of lncRNAs in regulation of DKD and diabetes-related cancer

Diabetes mellitus often results in several complications, such as diabetic kidney disease (DKD) and end-stage renal diseases (ESRDs). Cancer patients often have the dysregulated glucose metabolism. Abnormal glucose metabolism can enhance the tumor malignant progression. Recently, lncRNAs have been reported to regulate the key proteins and signaling pathways in DKD development and progression and in cancer patients with diabetes. In this review article, we elaborate the evidence to support the function of lncRNAs in development of DKD and diabetes-associated cancer. Moreover, we envisage that lncRNAs could be diagnosis and prognosis biomarkers for DKD and cancer patients with diabetes. Furthermore, we delineated that targeting lncRNAs might be an alternative approach for treating DKD and cancer with dysregulated glucose metabolism.