Upregulating microRNA-498 inhibits gastric cancer proliferation invasion and chemoresistance through inverse interaction of Bmi1

Interferon Gamma Receptor 2 Collaborates With Circular RNA/MicroRNA to Modulate Programmed Cell Death-Ligand 1 Levels in Nasopharyngeal Carcinoma

Background

The effectiveness of immune checkpoint therapy highlights the need to understand abnormal programmed cell death protein-1 (PD-1) expression in nasopharyngeal carcinoma (NPC), especially when treatments fail, or resistance develops. Interferon gamma (IFN-γ) signaling is crucial for regulating programmed cell death-ligand 1 (PD-L1) expression. Our study focuses on interferon gamma receptor 2 (IFNGR2), an essential part of the IFN-γ pathway, and its impact on malignant traits in NPC.

Methods

The expression levels of IFNGR2 and PD-L1 were accessed using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). To understand the cellular phenotypic effects, small interfering RNA (siRNA)/short hairpin RNA (shRNA) knockdown techniques were used to evaluate cell viability, clonogenic survival, migration and invasion, immunohistochemistry, and tumor formation assays. The relationship between IFNGR2 and microRNAs (miRNAs)/circular RNAs (circRNAs) will be verified using methods such as circRNA stability assay, rescue, and dual-luciferase reporter assay.

Results

IFNGR2 was significantly overexpressed in NPC, and its expression positively correlated with PD-L1 levels. This overexpression contributed to increased cell proliferation, migration, invasion, clonogenicity, and tumor growth. Additionally, we identified an oncogenic circular RNA, circ_001377, and uncovered a novel mechanism by which upregulation of circ_001377 competitively bound to miR-498-3p. This interaction reduced miR-498-3p's ability to target IFNGR2. As a result, the diminished miR-498-3p led to increased IFNGR2 expression, which subsequently activated the IFN-γ signaling pathway and drove abnormal PD-L1 expression.

Conclusions

IFNGR2 is an oncogenic factor in NPC. The circ_001377/miR-498-3p interaction drives IFNGR2 upregulation and PD-L1 overexpression, suggesting that targeting this axis could improve therapeutic outcomes.

Wilms' tumour gene 1 (WT1) enhances non-small cell lung cancer malignancy and is inhibited by microRNA-498-5p

BACKGROUND

Wilms' tumour gene 1 (WT1) is clearly recognized as a tumour promoter in diversiform of human malignancies. Nevertheless, knowledge of its expression, functions and potential molecular mechanisms in non-small cell lung cancer (NSCLC) remains elusive.

METHODS

Differential expression of WT1 mRNA and protein between NSCLC and normal tissues were assessed by analyzing RNA-seq data from Oncomine and protein data from Human Protein Atlas, respectively. Subsequently, prognosis significance and immune cell infiltration were analyzed by Kaplan-Meier plotter and CIBERSORT. 60 pairs of local NSCLC tissues were involved to validate WT1 expression by quantitative PCR (qPCR) and Western blot. Moreover, Cell Counting Kit-8 (CCK-8), colony formation, transwell, dual luciferase reporter assays and in vivo xenograft tumour growth experiments were conducted to explore the function and mechanism of WT1 in NSCLC.

RESULTS

Our solid data indicated that WT1 was increased in NSCLC tissues and cell lines in comparison with their matched controls. In particular, its upregulation correlated with worse prognosis and immune infiltration of the patients. Functional assays demonstrated that knockdown of WT1 inhibited NSCLC malignancy, including inhibiting cell proliferation, survival and invasion. Further exploration discovered that microRNA-498-5p (miR-498-5p) was the upstream suppressor of WT1 by directly targeting the 3' untranslated region (UTR) of WT1 mRNA. Moreover, expression of miR-498-5p was notably decreased and inversely correlated with WT1 in NSCLC tissues. Finally, we proved that miR-498-5p was a potent tumour suppressor in NSCLC by suppressing cell proliferation, survival and invasion, while WT1 restoration could in turn disrupt this suppression both in vitro and in vivo.

CONCLUSION

The abnormal increase in WT1 contributes to the malignant properties of NSCLC cells, and miR-498-5p is a natural inhibitor of WT1. Our findings might facilitate the development of novel therapeutic strategies against NSCLC in the future.

CEACAM5 targeted by miR-498 promotes cell proliferation, migration and epithelial to mesenchymal transition in gastric cancer

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CEACAM5 was upregulated in GC tissues and cells.

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CEACAM5 knockdown repressed GC cell migration, proliferation, and EMT.

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Knockdown of CEACAM5 suppressed the growth of GC cells in mice with transplanted tumor.

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CEACAM5 was predicted as a miR-498 target.

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MiR-498 reduced GC cell migration, proliferation, and EMT by inhibiting CEACAM5.

Objective

Recent studies have shown that carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) may serve as an independent predictor of advanced gastric cancer (GC). The purpose of this research is to explore the patterns of expression, functions, and upstream regulatory pathway of CEACAM5 in GC.

Methods

The levels of miR-498 and CEACAM5 expression in GC cells and tissues were measured via qRT-PCR. Wound-healing, CCK-8, and western blotting experiments were conducted for the evaluation of GC cell migration, proliferation, and epithelial-mesenchymal transition (EMT), respectively. The targeting relationship between miR-498 and CEACAM5 was validated via pull-down and luciferase reporter assays. Xenograft tumor mouse models were established to observe CEACAM5’s influence on the growth of tumors in vivo.

Results

Elevated levels of CEACAM5 were detected among the GC cells and tissues. The results of the in vitro experiments revealed that the knockdown of CEACAM5 in GC cells significantly inhibited their proliferation, migration, and EMT. Moreover, CEACAM5 inhibition effectively hampered GC cell growth within the nude mice. Moreover, miR-498 directly targeted CEACAM5. MiR-498 downregulation had been observed among the cells and tissues of GC. The stimulation of GC cell proliferation, migration, and EMT, which had been engendered by CEACAM5 overexpression, was reversible through the overexpression of miR-498.

Conclusion

The outcomes of this research suggest that miR-498 is capable of repressing the proliferation, migration, and EMT of GC cells through CEACAM5 downregulation.

The Role of MiRNA in Cancer: Pathogenesis, Diagnosis, and Treatment

Cancer is also determined by the alterations of oncogenes and tumor suppressor genes. These gene expressions can be regulated by microRNAs (miRNA). At this point, researchers focus on addressing two main questions: "How are oncogenes and/or tumor suppressor genes regulated by miRNAs?" and "Which other mechanisms in cancer cells are regulated by miRNAs?" In this work we focus on gathering the publications answering these questions. The expression of miRNAs is affected by amplification, deletion or mutation. These processes are controlled by oncogenes and tumor suppressor genes, which regulate different mechanisms of cancer initiation and progression including cell proliferation, cell growth, apoptosis, DNA repair, invasion, angiogenesis, metastasis, drug resistance, metabolic regulation, and immune response regulation in cancer cells. In addition, profiling of miRNA is an important step in developing a new therapeutic approach for cancer.

Vitamin D modulation and microRNAs in gastric cancer: prognostic and therapeutic role

Gastric adenocarcinoma arises after a complex interaction between the host and environmental factors. Tumor location and TNM are the tools that currently guide treatment decisions. Surgery is the only curative treatment, but relapse is common. After relapse or advanced staged disease survival is poor and systemic treatment has modestly improved survival. An association between sun exposure, vitamin D status and gastric cancer (GC) incidence and mortality has been reported. The molecular differences of the histological subtypes and the new molecular classifications account for the great heterogeneity of this disease and are the basis for the discovery of new therapeutic targets. New prognostic and predictive factors are essential and microRNAs (miRNAs) are endogenous small non-coding RNA molecules with a great potential for diagnosis, prognosis and treatment of cancer. There are hundreds of miRNAs with altered expression in tumor gastric tissue when compared to normal gastric tissue. Many of these miRNAs are associated with clinicopathological variables and survival in patients with GC. Furthermore, the expression of some of these miRNAs with prognostic importance in CG is influenced by vitamin D and others are mediators of some of the actions of this vitamin. This review aims to update the evidence on several miRNAs with prognostic value and therapeutic potential in GC, whose expression may be influenced by vitamin D or may regulate vitamin D signaling.

DUOX2 As a Potential Prognostic Marker which Promotes Cell Motility and Proliferation in Pancreatic Cancer

DUOX2 has been reported to highly express in several types of cancers. However, the prognostic significance and the biological function of DUOX2 expression with pancreatic cancer (PC) still remain unclear. The present study is aimed at investigating whether DUOX2 could act as a novel biomarker of prognosis and evaluating its effect on PC cell progression. The mRNA and protein expression of DUOX2 in PC cells and tissues were assessed by quantitative real-time PCR (RT-qPCR) and immunohistochemistry. The effect of DUOX2 expression on PC cell motility and proliferation was evaluated in vitro. The correlation between DUOX2 mRNA expression and clinicopathological features and its prognostic significance were analyzed according to the Gene Expression Profiling Interactive Analysis (GEPIA) website based on The Cancer Genome Atlas (TCGA) and the GTEx databases combined with our clinical information. According to bioinformatics analysis, we forecasted the upstream transcription factors (TFs) and microRNA (miRNA) regulatory mechanism of DUOX2 in PC. The expression of DUOX2 at transcriptional and protein level was dramatically increased in PC specimens when compared to adjacent nontumor specimens. Functionally, DUOX2 knockdown inhibited cell motility and proliferation activities. Our clinical data revealed that the patients had better postoperative overall survival (OS) with lower expression of DUOX2, which is consistent with GEPIA data. Multivariate analysis revealed that high DUOX2 expression was considered as an independent prognostic indicator for OS (P = 0.031). Based on Cistrome database, the top 5 TFs of each positively and negatively association with DUOX2 were predicted. hsa-miR-5193 and hsa-miR-1343-3p targeting DUOX2 were forecasted from TargetScan, miRDB, and DIANA-TarBase databases, which were negatively correlated with OS (P = 0.043 and P = 0.0088, respectively) and DUOX2 expression (P = 0.0093 and P = 0.0032, respectively) in PC from TCGA data. These findings suggest that DUOX2 acts as a promising predictive biomarker and an oncogene in PC, which could be a therapeutic target for PC.

Non-coding RNAs underlying chemoresistance in gastric cancer

BACKGROUND

Gastric cancer (GC) is a major health issue in the Western world. Current clinical imperatives for this disease include the identification of more effective biomarkers to detect GC at early stages and enhance the prevention and treatment of metastatic and chemoresistant GC. The advent of non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long-non coding RNAs (lncRNAs), has led to a better understanding of the mechanisms by which GC cells acquire features of therapy resistance. ncRNAs play critical roles in normal physiology, but their dysregulation has been detected in a variety of cancers, including GC. A subset of ncRNAs is GC-specific, implying their potential application as biomarkers and/or therapeutic targets. Hence, evaluating the specific functions of ncRNAs will help to expand novel treatment options for GC.

CONCLUSIONS

In this review, we summarize some of the well-known ncRNAs that play a role in the development and progression of GC. We also review the application of such ncRNAs in clinical diagnostics and trials as potential biomarkers. Obviously, a deeper understanding of the biology and function of ncRNAs underlying chemoresistance can broaden horizons toward the development of personalized therapy against GC.

CircPDZD8 promotes gastric cancer progression by regulating CHD9 via sponging miR-197-5p

CircRNAs have been shown to be associated with gastric cancer tumorigenesis. But little was known about the role of circPDZD8 in gastric cancer. CircPDZD8 was up-regulated in gastric cancer tissues and cells, Kaplan-Meier survival analysis indicated that gastric patients had a poor overall survival when circPDZD8 levels were high. CircPDZD8 knockdown could hinder proliferation and migration of gastric cancer cells. MiR-197-5p, which was down-regulated in gastric cancer, was shown to be a target of circPDZD8 and was inversely correlated with circPDZD8 expression. CHD9, as a target gene of miR-197-5p, was negatively regulated by miR-197-5p and positively correlated with circPDZD8 expression. Importantly, circPDZD8 could up-regulate CHD9 expression by sponging miR-197-5p, and modulate cell progression by regulation of the miR-197-5p/CHD9 axis in gastric cancer. CircPDZD8 knockdown repressed the progression of gastric cancer cells by sponging miR-197-5p and down-regulating CHD9.

Propofol suppresses hypoxia-induced esophageal cancer cell migration, invasion, and EMT through regulating lncRNA TMPO-AS1/miR-498 axis

Background

Propofol has been reported to be related to the migration, invasion, and epithelial‐mesenchymal transition (EMT) of esophageal cancer (EC) cells. However, the detailed mechanism has not yet been fully reported. The purpose of this research was to elucidate the function of long non‐coding RNA TMPO antisense RNA 1 (lncRNA TMPO‐AS1) and microRNA‐498 (miR‐498) in propofol‐regulated EC.

Methods

Transwell assay was performed to assess cell migratory and invasive abilities. Western blot assay was employed to determine the levels of EMT markers and hypoxia inducible factor‐1 (HIF‐1α). Quantitative real‐time polymerase chain reaction (qRT‐PCR) was carried out to detect the levels of TMPO‐AS1 and miR‐498. Moreover, the interaction between TMPO‐AS1 and miR‐498 was predicted by starBase, and then confirmed by the dual‐luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

Results

Propofol suppressed hypoxia‐induced EC cell migration, invasion, and EMT. Both TMPO‐AS1 overexpression and miR‐498 knockdown weakened the effect of propofol on hypoxia‐induced EC cell progression. Interestingly, TMPO‐AS1 targeted miR‐498 and suppressed miR‐498 expression. TMPO‐AS1 regulated EC cell progression via downregulating miR‐498 expression.

Conclusions

Collectively, our findings demonstrated that propofol inhibited hypoxia‐induced EC cell mobility through modulation of the TMPO‐AS1/miR‐498 axis, providing a theoretical basis for the treatment of EC.

MicroRNA-4268 inhibits cell proliferation via AKT/JNK signalling pathways by targeting Rab6B in human gastric cancer

MicroRNAs (miRNAs) play critical roles in the tumorigenesis and progression of gastric cancer (GC). However, the biological function of miR-4268 in GC and its mechanism remain unclear. In the present study, qTR-PCR found that the expression of miR-4268 was significantly downregulated in GC tissues and cell lines. The overexpression of miR-4268 inhibited GC cell proliferation and the cell cycle G1/S phase transition, and induced cell apoptosis. In contrast, inhibition of miR-4268 promoted cell proliferation and G1-S transition, and suppressed cell apoptosis. Further analyses revealed that miR-4268 expression was negatively correlated with Rab6B expression in GC tissues. Rab6B was verified to be a direct target of miR-4268. Notably, silencing Rab6B resulted in the same biological effects in GC cells as those induced by overexpression of miR-4268. Importantly, both miR-4268 overexpression and Rab6B silence inhibited the AKT/JNK signaling pathways, which modulated cell cycle regulators (Cyclin D1 and CDK4). In contrast, inhibition of miR-4268 promoted the AKT/JNK signaling pathways. MiR-4268 overexpression also promoted the p38 MAPK signaling pathway. Taken together, miR-4268 suppresses GC cell proliferation through inhibiting the AKT/JNK signaling pathways by targeting Rab6B and induces cell apoptosis through promoting the p38 MAPK signaling pathway. Our findings indicate a tumor-suppressor role of miR-4268 in GC pathogenesis and the potential of miR-4268 in GC theropy.

Long Non-Coding RNA Taurine Upregulated Gene 1 (TUG1) Downregulation Constrains Cell Proliferation and Invasion through Regulating Cell Division Cycle 42 (CDC42) Expression Via MiR-498 in Esophageal Squamous Cell Carcinoma Cells

Background

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor of the gastrointestinal tract. Taurine upregulated gene 1 (TUG1), a long non-coding (lnc) RNA, also known as LIN00080 or TI-227H, was connected with the tumorigenesis of various diseases. Hence, we plumed the role and molecular mechanism of TUG1 in the progression of ESCC.

Material/Methods

Expression patterns of TUG1, microRNA-498 (miR-498), and cell division cycle 42 (CDC42) mRNA were assessed using quantitative real time polymerase chain reaction (qRT-PCR). The expression level of CDC42 protein was evaluated via western blot analysis. Cell proliferation and invasion were determined with Cell Counting Kit-8 (CCK-8) assay or Transwell assay. The relationship between miR-498 and TUG1 or CDC42 was predicted by online bioinformatics database LncBase Predicted v.2 or microT-CDS and confirmed through dual-luciferase reporter system or RNA immunoprecipitation assay (RIP).

Results

TUG1 and CDC42 were upregulated while miR-498 was strikingly decreased in ESCC tissues and cells (P<0.0001). Besides, TUG1 suppression blocked the proliferation and invasion of ESCC cells (P<0.001). Importantly, TUG1 decrease restrained CDC42 expression via binding to miR-498 in ESCC cells. Also, the suppressive impacts of TUG1 silencing on the proliferation and invasion of ESCC cells were mitigated by miR-498 reduction. Meanwhile, the repression of proliferation and invasion induced by miR-498 elevation was weakened by CDC42 overexpression.

Conclusions

Inhibition of TUG1 hampered cell proliferation and invasion by downregulating CDC42 via upregulating miR-498 in ESCC cells. Thus, TUG1 might be an underlying therapeutic target for ESCC.

MicroRNA-498 inhibits the proliferation, migration and invasion of gastric cancer through targeting BMI-1 and suppressing AKT pathway

Recently, microRNA-498 (miR-498) plays important effect in human cancers. Nonetheless, the role of miR-498 is still unclear in gastric cancer (GC). Therefore, this study was designed to investigate the function of miR-498 in GC tissues and cell lines (SGC-7901, BGC-823, MGC-803). The expressions of miR-498 and BMI-1 were examined in GC tissues via the RT-qPCR assay. The function of miR-498 was investigated through MTT and transwell assays. The relationship between miR-498 and BMI-1 was testified by dual luciferase assay. The protein expression of EMT markers, AKT pathway markers and BMI-1 was measured through western blot. The expression of miR-498 was decreased in GC tissues which predicted poor prognosis of GC patients. Moreover, functional analyses show that the overexpression of miR-498 inhibited the progression of GC. Furthermore, BMI-1 was a direct target of miR-498 which was upregulated in GC. Especially, the upregulation of BMI-1 recovered the suppressive effect of miR-498 in GC. In addition, miR-498 inhibited the metastasis and proliferation of GC cells through blocking EMT and AKT pathway. MiR-498, by targeting BMI-1, presents a plethora of tumor suppressor activities in GC cells.

LncRNA CASC9 Suppressed the Apoptosis of Gastric Cancer Cells through Regulating BMI1

Long noncoding RNAs (lncRNAs) play important roles in regulating the apoptosis of gastric cancer (GC) cells. This study aims to investigate the underlying mechanism of lncRNA CASC9 in regulating the apoptosis of GC cells. The expressions of lncRNA and protein in GC tissues and cell lines were detected by qRT-PCR and western blot. GC cell apoptosis was detected by flow cytometry analysis. RNA pull-down and RNA immunoprecipitation (RIP) assays were conducted to verify the interaction between CASC9 and BMI1. LncRNA CASC9 was upregulated in GC tissue and GC cells, and high CASC9 expression was positively correlated with TNM stage and lymph node metastasis. Silencing CASC9 promoted the apoptosis of GC cells. LncRNA CASC9 could interact with BMI1 and positively regulate BMI1 expression. Silencing CASC9 promoted the ubiquitination of BMI1. In addition, lncRNA CASC9 regulated the apoptosis of GC cells through BMI1. Furthermore, interfering CASC9 inhibited the tumor growth of GC. LncRNA CASC9 could interact with BMI1 to regulate the degradation of BMI1, thus to affect the apoptosis of GC cells and suppressed tumor growth.