Lung cancer is the most frequent cause of mortality in cancer patients; non-small-cell lung cancer (NSCLC) accounts for ~80% of lung cancer cases. MicroRNAs (miRNAs) have been revealed to perform an important role in cancer development and progression. Based on a custom miRNA microarray analysis of patients with NSCLC, miRNA-615-3p (miR-615-3p) downregulation was identified in NSCLC tissues compared with normal lung tissues, which suggested that miR-615-3p acted as a tumor suppressor in lung cancer. The overexpression of miR-615-3p was then validated using 40 pairs of NSCLC and adjacent normal tissue samples using a TaqMan reverse transcription-quantitative polymerase chain reaction assay. In order to investigate the tumor suppressor function of miR-615-3p, the ectopic expression of miR-615-3p in the NSCLC A549, H1299 and H1650 cell lines was established. The results revealed that overexpressed miR-615-3p markedly inhibited cell proliferation and colony formation in the 3 NSCLC cell lines compared with the cells overexpressing the negative control sequence (NC). Additional investigation revealed that miR-615-3p overexpression significantly induced apoptosis and cell cycle arrest at the G1 phase in the A549, H1299 and H1650 cell lines compared with the cells overexpressing NC. Finally, ectopic expression of miR-615-3p was found to repress the cell migration and invasion of the 3 lung cancer cell lines. The results of the present study demonstrate, for the first time, that miR-615-3p functions as a tumor suppressor in NSCLC, and may be a novel potential molecular therapeutic target for patients with NSCLC.
Deregulated microRNAs play an important role in the development and progression of various types of cancer. In our previous study, we observed that microRNA‑342‑3p (miR‑342‑3p) was one of the most markedly downregulated microRNAs in two nasopharyngeal carcinoma (NPC) cell lines compared to non‑neoplastic cells by using whole genome small RNA sequencing. In the present study, we confirmed that the expression of miR‑342‑3p was significantly reduced in NPC tissues compared with normal nasopharyngeal epithelial tissues. Overexpression of miR‑342‑3p inhibited proliferation, epithelial‑mesenchymal transition (EMT), migration and invasiveness of NPC cells. In addition, we observed that Cdc42, a Rho GTPase family member involved in cell proliferation and metastasis, is a direct target of miR‑342‑3p. Additionally, ML141, a small‑molecule inhibitor of Cdc42, efficiently suppressed the invasion of NPC cells compared with the control cells. Finally, we analyzed NPC tissues derived from 10 NPC patients and subjected them to quantitative RT‑PCR and immunohistochemistry assays for concomitant determination of the expression levels of miR‑342‑3p and Cdc42. Our results revealed that miR‑342‑3p levels were significantly inversely correlated with the protein levels of its target Cdc42. The results of the present study indicated that miR‑342‑3p inhibited NPC tumor growth and invasion by directly targeting the Cdc42 pathway.
Abstract Background Long non-coding RNAs (lncRNAs) play vital roles in the development and progression of non-small-cell lung cancer (NSCLC); however, the role of most lncRNAs in NSCLC remains unknown. This study explored the clinical significance, biological function and underlying mechanism of lnc-GAN1 in NSCLC. Methods With a custom lncRNA microarray we found that lnc-GAN1 is markedly downregulated in NSCLC tissues. Then lnc-GAN1 expression level was measured using qRT-PCR in NSCLC tissues and cell lines. Survival was assessed using the Kaplan-Meier method. The biological functions of lnc-GAN1 in lung cancer cells were evaluated in vitro and in vivo. RNA fluorescence in situ hybridization and subcellular localization assays revealed the subcellular distribution of lnc-GAN1 in cells. Bioinformatic analysis was adopted to predict miRNAs and signaling pathways regulated by lnc-GAN1. RNA immunoprecipitation and Dual-luciferase reporter assays were used to assess the interaction between lnc-GAN1 and miR-26a-5p in lung cancer cells. Results lnc-GAN1 is downregulated in HCC tissues and associated with larger tumor size and poor overall survival and disease-free survival; its ectopic expression suppresses cell proliferation, colony formation, and cell cycle progression and induces apoptosis in NSCLC cells; it also inhibits tumor growth in the NSCLC xenograft model. We further proved that lnc-GAN1 is localized in cytoplasm and transcribed independently from its parental gene GAN. Mechanistically, lnc-GAN1 acts as a sponge for miR-26a-5p by two seed sequences, and the two non-coding RNAs have a negative relationship in NSCLC tissues; we further prove that PTEN is a direct target of miR-26a-5p and lnc-GAN1 inhibits cell cycle signaling pathway by activating PTEN, whose expression level correlated negatively with miR-26a-5p level but positively with lnc-GAN1 level in NSCLC samples. Conclusions Lnc-GAN1 is downregulated and associated with poor survival of NSCLC patients, and mechanistically acts as a tumor suppressor via sponging and inhibiting miR-26a-5p to upregulate PTEN. This study provides a potential prognostic biomarker and treatment target for NSCLC.
Recent studies demonstrate that immune checkpoint inhibitor (ICI) therapy has achieved success in many types of advanced cancers including advanced hepatocellular carcinoma (HCC).However, ICI therapy is beneficial in only some HCC patients, suggesting that immune-responses are highly variable in HCCs.Therefore, understanding the immune status in HCC microenvironment will facilitate ICI immunotherapy and guide patient selection for the therapy.In this study, we first analyzed the expression profile of immune-modulating genes and their relationship with survival of HCC patients using the data downloaded from The Cancer Genome Atlas -Liver Hepatocellular Carcinoma (TCGA-LIHC) database, and found that the higher expressions of CD276 (B7-H3) and CD47 were significantly associated with poor survival.Then we identified 4 immune subtypes of HCCs with different survivals by using the combination expression of B7-H3 (or CD47) and CD8.Patients with B7-H3 low /CD8 high or CD47 low /CD8 high have the best survival while ones with B7-H3 high /CD8 low or CD47 high /CD8 low have the worst survival.The 4 immune subtypes were validated in another 72 HCC patients obtained from South China.In conclusion, our findings suggest that HCC patient prognosis is associated with immunophenotypes by T cell infiltration (CD8 expression) and the expression of the adaptive immune resistance gene (B7-H3 or CD47), and this immune classification system will facilitate HCC patient selection for ICI immunotherapy.
Nasopharyngeal carcinoma (NPC) is a highly aggressive neoplasm mainly distributed in the eastern and southeastern parts of Asia. NPC has a poor prognosis among head and neck cancers, and molecular-targeted therapies showed limited clinical efficacy.We reviewed publications in the PubMed database and extracted genes associated with NPC. The online tool WebGestalt was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for these genes. Next, the two parameters, Jaccard Coefficient (JC) and Overlap Coefficient (OC), were used to analyze the crosstalk of each pair of selected pathways. The new NPC-related genes were predicted by protein-protein interaction (PPI) network combined with hub genes extraction. Western blotting, qRT-PCR, and immunohistochemistry (IHC) were used to detect the expression of candidate genes in NPC cells and tissues, and cellular function assays were used to explore the effects of genes on NPC cells.A total of 552 genes were identified and used to build an NPC-related gene set (NPCgset). Pathways enriched in KEGG pathway analysis were further used for crosstalk analysis and were grouped into two modules: one was related to the carcinogenesis process, and the other was correlated with the immune response. Eight genes from the NPCgset were selected to build a PPI network, and two hub genes PIK3CA and AKT1 were chosen. Proteins interacting with PIK3CA were analyzed; among them, the expression of RRAS was down-regulated in NPC and associated with poor prognosis of NPC patients. Furthermore, RRAS suppressed proliferation, invasion and the epithelial-mesenchymal transformation (EMT) of the HK1 and 5-8F cell lines.Our study may help to explore the biological processes underlying NPCgset and suggests that RRAS may act as a tumor suppressor gene in NPC.
Abstract Background Previous findings have indicated that the tumor, nodes, and metastases (TNM) staging system is not sufficient to accurately predict survival outcomes in patients with non-small lung carcinoma (NSCLC). Thus, this study aims to identify a long non-coding RNA (lncRNA) signature for predicting survival in patients with NSCLC and to provide additional prognostic information to TNM staging system. Methods Patients with NSCLC were recruited from a hospital and divided into a discovery cohort (n = 194) and validation cohort (n = 172), and detected using a custom lncRNA microarray. Another 73 NSCLC cases obtained from a different hospital (an independent validation cohort) were examined with qRT-PCR. Differentially expressed lncRNAs were determined with the Significance Analysis of Microarrays program, from which lncRNAs associated with survival were identified using Cox regression in the discovery cohort. These prognostic lncRNAs were employed to construct a prognostic signature with a risk-score method. Then, the utility of the prognostic signature was confirmed using the validation cohort and the independent cohort. Results In the discovery cohort, we identified 305 lncRNAs that were differentially expressed between the NSCLC tissues and matched, adjacent normal lung tissues, of which 15 are associated with survival; a 4-lncRNA prognostic signature was identified from the 15 survival lncRNAs, which was significantly correlated with survivals of NSCLC patients. This signature was further validated in the validation cohort and independent validation cohort. Moreover, multivariate Cox analysis demonstrates that the 4-lncRNA signature is an independent survival predictor. Then we established a new risk-score model by combining 4-lncRNA signature and TNM staging stage. The receiver operating characteristics (ROC) curve indicates that the prognostic value of the combined model is significantly higher than that of the TNM stage alone, in all the cohorts. Conclusions In this study, we identified a 4-lncRNA signature that may be a powerful prognosis biomarker and can provide additional survival information to the TNM staging system.
Background: miR-18a has been reported to be upregulated in nasopharyngeal carcinoma (NPC) tissues by microarray assays. This study aimed to investigate the roles and the underlying molecular mechanisms of miR-18a in NPC.Methods: Real-time RT-PCR was used to quantify miR-18a expression in NPC samples. In vitro and in vivo studies were performed to verify the biological roles of miR-18a in NPC. Candidate genes under regulation by miR-18a were screened out through a whole-genome microarray assay, further identified by a reporter assay and verified in clinical samples. In vivo tumor suppression by miR-18a was assessed in nude mice by intratumor injection of antagomir-18a.Findings: miR-18a expression was upregulated in NPC tissues and positively correlated with tumor size and TNM stages. The ectopic expression of miR-18a promoted NPC cell growth, migration and invasion, while the repression of miR-18a resulted in opposite effects. Moreover, miR-18a expression could be upregulated by NF-κB activation or Epstein-Barr virus encoded latent membrane protein 1 expression. SMG1, a phosphoinositide 3-kinase-related kinases family member and an mTOR antagonist, was identified as functional target of miR-18a. Our results confirmed that miR-18a exerts its oncogenic role through suppression of SMG1 and activation of mTOR pathway in NPC cells. Importantly, in vivo xenograft tumor growth in nude mice was effectively inhibited by intratumor injection of miR-18a antagomir.Interpretation: Our data support an oncogenic role of miR-18a through a novel miR-18a/SMG1/mTOR axis and suggest that the antitumor effects of antagomir-18a may make it suitable for NPC therapy.Funding Statement: This work was supported by grants from the National Nature Science Foundation of China (Nos. 81772884, 81772991, 81773026 and 81372886) and Research Fund of State Key Laboratory of Oncology in South China (No. 010811).Declaration of Interests: The authors declare no conflicts of interest.Ethics Approval Statement: This study was approved by the Research Ethics Committee of Sun Yat-sen University Cancer Center, and written informed consent was obtained from each participant. Animals were housed under standard conditions and cared for according to the institutional guidelines for animal care. The experiments were performed in accordance with the guidelines of the laboratory animal ethics committee of Sun Yat-sen University Cancer Center.
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