Linc01133 contributes to gastric cancer growth by enhancing YES1-dependent YAP1 nuclear translocation via sponging miR-145-5p.
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ABSTRACT: The long intergenic non-coding RNA linc01133 is reported to be oncogenic in various malignancies. However, the role and mechanism of linc01133 in regulating gastric cancer growth is still not clear. In the present study, we found that linc01133 was significantly upregulated in gastric cancer tissues compared to non-tumorous gastric tissues. Linc01133 over-expression significantly correlated with tumor size and tumor differentiation in gastric cancer patients. The expression of linc01133 was regulated by c-Jun and c-Fos collaboratively. In both in vitro and in vivo studies, linc01133 was shown to promote gastric cancer cell growth. Linc01133 localized in the cytoplasm and functioned as an endogenous competing RNA of miR-145-5p to upregulate the expression of YES1, which was proved to be the target gene of miR-145-5p. By promoting YES1-dependent YAP1 nuclear translocation, linc01133 upregulated the expression of the key cell cycle regulators CDK4, CDK6 and cyclin D1 to promote G1-S phase transition. Thus, our study unveiled the function and mechanism of linc01133 regulating cell cycle progression in gastric cancer.
Project description:BackgroundCircular RNAs (circRNAs) as a novel subgroup of non-coding RNAs act a critical role in the pathogenesis of gastric cancer (GC). However, the underlying mechanisms by which hsa_circ_0003855 (circDUSP16) contributes to GC are still undocumented.MaterialsThe differentially expressed circRNAs were identified by GEO database. The association of circDUSP16 or miR-145-5p expression with clinicopathological features and prognosis in GC patients was analyzed by FISH and TCGA-seq data set. Loss- and gain-of-function experiments as well as a xenograft tumor model were performed to assess the role of circDUSP16 in GC cells. circDUSP16-specific binding with miR-145-5p was confirmed by bioinformatic analysis, luciferase reporter, and RNA immunoprecipitation assays.ResultsThe expression levels of circDUSP16 were markedly increased in GC tissue samples and acted as an independent prognostic factor of poor survival in patients with GC. Knockdown of circDUSP16 repressed the cell viability, colony formation, and invasive potential in vitro and in vivo, but ectopic expression of circDUSP16 reversed these effects. Moreover, circDUSP16 possessed a co-localization with miR-145-5p in the cytoplasm, and acted as a sponge of miR-145-5p, which attenuated circDUSP16-induced tumor-promoting effects and IVNS1ABP expression in GC cells. MiR-145-5p had a negative correlation with circDUSP16 expression and its low expression was associated with poor survival in GC patients.ConclusionsCircDUSP16 facilitates the tumorigenesis and invasion of GC cells by sponging miR-145-5p, and may provide a novel therapeutic target for GC.
Project description:Gastric cancer (GC) is one of the most common and malignant pathologies, and a significant portion of GC incidences develops from Helicobacter pylori (Hp)-induced chronic gastritis. Although the exact mechanisms of GC are complex and poorly understood, gastric carcinogenesis is a good model to investigate how inflammation and infection collaboratively promote tumorigenesis. Yes-associated protein 1 (YAP1) is the key effector of the Hippo pathway, which is silenced in most human cancers. Herein, we verified the tumor-promoting effect of YAP1 in vitro, in vivo, and in human specimens. We revealed that YAP1 displays nuclear translocation and works with TEAD to activate transcription of the crucial inflammatory cytokine IL-1β in gastric cells infected with Hp. As IL-1ß accounts for inflammation-associated tumorigenesis, this process can lead to gastric carcinogenesis. Thus, in addition to activating proliferation genes, YAP1 also plays a major role in inflammation amplification by activating inflammatory cytokine genes. Excitingly, our research demonstrates that transfection of mutant plasmid YAP-5SA/S94A or addition of the drug verteporfin, both of which are thought to disrupt the YAP1-TEAD interaction, can arrest the carcinogenesis process. These findings can provide new approaches to GC treatment.
Project description:BackgroundLong noncoding RNAs (lncRNAs) are functionally associated with cancer development and progression. Although gene copy number variation (CNV) is common in hepatocellular carcinoma (HCC), it is not known how CNV in lncRNAs affects HCC progression and recurrence. We aimed to identify a CNV-related lncRNA involved in HCC progression and recurrence and illustrate its underlying mechanisms and prognostic value.MethodsWe analyzed the whole genome sequencing (WGS) data of matched cancerous and noncancerous liver samples from 49 patients with HCC to identify lncRNAs with CNV. The results were validated in another cohort of 238 paired HCC and nontumor samples by TaqMan copy number assay. We preformed Kaplan-Meier analysis and log-rank test to identify lncRNA CNV with prognostic value. We conducted loss- and gain-of-function studies to explore the biological functions of LINC01133 in vitro and in vivo. The competing endogenous RNAs (ceRNAs) mechanism was clarified by microRNA sequencing (miR-seq), quantitative real-time PCR (qRT-PCR), western blot, and dual-luciferase reporter assays. We confirmed the binding mechanism between lncRNA and protein by RNA pull-down, RNA immunoprecipitation, qRT-PCR, and western blot analyses.ResultsGenomic copy numbers of LINC01133 were increased in HCC, which were positively related with the elevated expression of LINC01133. Increased copy number of LINC01133 predicted the poor prognosis in HCC patients. LINC01133 overexpression in HCC cells promoted proliferation and aggressive phenotypes in vitro, and facilitated tumor growth and lung metastasis in vivo, whereas LINC01133 knockdown had the opposite effects. LINC01133 sponged miR-199a-5p, resulting in enhanced expression of SNAI1, which induced epithelial-to-mesenchymal transition (EMT) in HCC cells. In addition, LINC01133 interacted with Annexin A2 (ANXA2) to activate the ANXA2/STAT3 signaling pathway.ConclusionsLINC01133 promotes HCC progression by sponging miR-199a-5p and interacting with ANXA2. LINC01133 CNV gain is predictive of poor prognosis in patients with HCC.
Project description:BackgroundLong-non-coding RNA PVT1 (lncRNA PVT1) can be used as an oncogenic regulatory non-coding RNA (ncRNA) for many cancers. However, its function and mechanism in breast cancer (BRCA) are still not clearly elucidated.ObjectiveWe attempt to explain the mechanism of PVT1's role in breast cancer from different perspectives.MethodsWe analyzed the expression of PVT1 and its correlation with the breast cancer related clinical data in the The Cancer Genome Atlas (TCGA) database. We used PVT1 overexpression and knockdown lentivirus to infect breast cancer MDA-MB-231 cell line for cell function verification, in vitro using CCK-8 to measure proliferation, flow cytometry to measure apoptosis, transwell test to measure invasion and migration ability, detecting cell extracellular acidification rate (ECAR) to assess glycolysis metabolism and explore the biological functions of PVT1 in breast cancer cells. Transcriptome sequencing was used to analyze the changes of related genes in cells after overexpression of PVT1. In vivo we used a xenograft model to study the effect of PVT1 on breast cancer.ResultsPVT1 was up-regulated in breast cancer tissues and was positively correlated with the clinical stage of breast cancer patients. Overexpression of PVT1 in vitro promoted cell proliferation, migration and invasion, and promoted tumor growth in vivo. Knockdown of PVT1 led to the opposite biological consequence. Further bioinformatics analysis showed that PVT1 changes the glycolysis metabolism of tumors through regulation of glycolysis-related genes. In addition, the expression of miR-145-5p is negatively correlated with PVT1. We consider the possibility of PVT1 promoting cell proliferation and metastasis by regulating the aerobic glucose metabolism in breast cancer cells through sponging the miR-145-5p.ConclusionOur results reveal a potential pathway for competing endogenous RNA to regulate breast cancer glucose metabolism. PVT1 regulates glycolysis related genes expression by competitively binding to endogenous miR-145-5p in breast cancer cells to change the metabolic phenotype. This may Provide new ideas for precise molecular therapy targets for breast cancer.
Project description:Brain metastasis is a major cause of morbidity and mortality of lung cancer patients. We assessed whether aberrant expression of specific microRNAs could contribute to brain metastasis. Comparison of primary lung tumors and their matched metastatic brain disseminations identified shared patterns of several microRNAs, including common down-regulation of miR-145-5p. Down-regulation was attributed to methylation of miR-145's promoter and affiliated elevation of several protein targets, such as EGFR, OCT-4, MUC-1, c-MYC and, interestingly, tumor protein D52 (TPD52). In line with these observations, restored expression of miR-145-5p and selective depletion of individual targets markedly reduced in vitro and in vivo cancer cell migration. In aggregate, our results attribute to miR-145-5p and its direct targets pivotal roles in malignancy progression and in metastasis.
Project description:BackgroundCircular RNAs (circRNAs) have displayed important roles in the development and progression of various cancers. However, the functions of the majority of circRNAs in osteosarcoma (OS) remain unknown.MethodsCircular RNA microarray analysis was performed in three OS cell lines (Saos-2, U2OS and MG63) and normal vascular endothelial cells. The co-differentially expressed circRNAs (CDECs) were identified in OS cell lines with the criterion of FDR (false discovery rate) < 0.05 and |fold change (FC)|> 2. Quantitative real-time PCR was used to validate the expression levels of selected CDECs. A series of functional assays, including MTT assay, flow cytometry and transwell assay were conducted in OS cells. The interaction between circRNA and miRNAs was confirmed by luciferase reporter assay and RNA immunoprecipitation assay.ResultsA total of 241 CDECs, including 75 upregulated and 166 downregulated CDECs, were identified in three OS cell lines compared with normal vascular endothelial cells. PCR validation showed that hsa_circ_0000704, hsa_circ_0001017 and hsa_circ_0005035 were all highly expression in the three OS cell lines, compared with osteoblast cell lines (HECC, hFOB1.19 and HFF-1). Functionally, overexpression of circ_0001017 significantly promoted the cell proliferation, migration and invasion and decreased apoptosis in U2OS cells. Knockdown of circ_0001017 obtained the opposite results. Circ_0001017 may downregulate miR-145-5p through direct binding. Furthermore, the expression of miR-145-5p was negatively regulated by circ_0001017 in OS cells. In addition, further functional studies indicated that miR-145-5p inhibitor eliminated the effects caused by si-circ_0001017 in OS cells.ConclusionsIn conclusion, our study suggested that circ_0001017 may be a novel oncogenic factor during the progression and development of OS by targeting miR-145-5p.
Project description:Gastric cancer (GC) is a significant public health burden worldwide, and cisplatin resistance is the leading cause for the failure of chemotherapy in this disease. Previous studies have revealed that HOXA transcript at the distal tip (HOTTIP) is involved in the pathology of GC and is associated with poor overall survival. However, the functional role of HOTTIP in GC chemoresistance remains unclear. In this study, quantitative real-time PCR was used to analyze HOTTIP expression in GC cell lines and in tissues of GC patients who received cisplatin-based chemotherapy. The mechanism of HOTTIP-mediated chemoresistance was assessed using cell viability, apoptosis, and autophagy assays. The relationships among HOTTIP, miR-216a-5p, and Bcl-2 were determined using luciferase reporter and western blot assays. HOTTIP was markedly upregulated in the tissues of GC patients who were treated with gastrectomy and cisplatin chemotherapy, especially in those with recurrent tumors. Further, HOTTIP was increased in the cisplatin-resistant cell line, SGC7901/DDP, compared to the parental cells, SGC7901. Functional assays demonstrated that HOTTIP expression promoted cisplatin resistance and inhibited apoptosis and autophagy in GC cells. Mechanistic investigations revealed that HOTTIP may regulate the functions of GC cells by sponging miR-216a-5p. MiR-216a-5p overexpression decreased Bcl-2 expression, enhanced Beclin1 expression, and active autophagy. Taken together, our study demonstrated that HOTTIP is closely associated with recurrence in GC patients. HOTTIP expression confers cisplatin resistance by regulating the miR-216a-5p/BCL-2/Beclin1/autophagy pathway, which provides a novel strategy to overcome resistance to chemotherapy in GC.
Project description:Purpose:To gain a deeper insight into how circSry regulates spermatogenesis in spermatocytes, RNA-sequencing (RNA-seq) was performed to analyze the genome-wide changes by circSry deletion.
Project description:BackgroundThe aberrant expression of microRNA-140-5p (miR-140-5p) has been described in gastric cancer (GC). However, the role of miR-140-5p in GC remains unclear. In this study, the prognostic relevance of miR-140-5p in GC was investigated and YES1 was identified as a novel target of miR-140-5p in regulating tumor progression.MethodsmiR-140-5p level was determined in 20 paired frozen specimens through quantitative real-time PCR, and analyzed in tissue microarrays through in situ hybridization. The target of miR-140-5p was verified through a dual luciferase reporter assay, and the effects of miR-140-5p on phenotypic changes in GC cells were investigated in vitro and in vivo.ResultsCompared with that in adjacent normal tissues, miR-140-5p expression decreased in cancerous tissues. The downregulated miR-140-5p in 144 patients with GC was significantly correlated with the reduced overall survival of these patients. miR-140-5p could inhibit GC cell proliferation, migration and invasion by directly targeting 3'-untranlated region of YES1. miR-140-5p could also remarkably reduce the tumor size in GC xenograft mice.ConclusionsmiR-140-5p serves as a potential prognostic factor in patients with GC, and miR-140-5p mediated YES1 inhibition is a novel mechanism behind the suppressive effects of miR-140-5p in GC.
Project description:Osteosarcoma is the most common primary malignant bone tumor in adolescents. While chemotherapy combined with surgery can improve the prognosis of some patients, chemo-resistance is still a huge obstacle in osteosarcoma treatment. Accumulating evidence demonstrates that circular RNAs (circRNAs) are involved in cancer progression and metastasis, but their specific role in osteosarcoma remains mostly undescribed. In this study, we performed circRNA deep sequencing and identified 88 distinct circRNAs from a human osteosarcoma cell lines group (143B, HOS, SJSA, and U2OS) and the human osteoblast hFOB 1.19 (control). We found that circCAMSAP1, also named hsa_circ_0004338, is significantly upregulated in human osteosarcoma tissues and cell lines, and it is positively correlated with osteosarcoma development. Silencing of circCAMSAP1 effectively suppresses osteosarcoma cell growth, apoptosis, migration, and invasion. Furthermore, we validated that circCAMSAP1 functions in osteosarcoma tumorigenesis through a circCAMSAP1/miR-145-5p/friend leukemia virus integration 1 (FLI1) pathway. FLI1 promotes osteosarcoma tumorigenesis and miR-145-5p suppresses FLI translation. circCAMSAP1 directly sequesters miR-145-5p in the cytoplasm and inhibits its activity to suppress osteosarcoma tumorigenesis. Moreover, the regulatory role of circCAMSAP1 upregulation was examined and validated in rats. In summary, our findings provide evidence that circCAMSAP1 act as a "microRNA sponge" and suggest a new therapeutic target of human osteosarcoma.