EpCAM knockdown alters microRNA expression in retinoblastoma--functional implication of EpCAM regulated miRNA in tumor progression.
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ABSTRACT:
SUBMITTER: Beta M
PROVIDER: S-EPMC4264963 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Medulloblastoma is the most common malignant brain tumor in children. SPARC (secreted protein acidic and rich in cysteine), a multicellular non-structural glycoprotein is known to be involved in multiple processes in various cancers. Previously, we reported that SPARC expression significantly impairs medulloblastoma tumor growth in vitro and in vivo and also alters chemo sensitivity. MicroRNAs are a class of post-transcriptional gene regulators with critical functions in tumor progression. In addition, microRNA (miRNA) expression changes are also involved in chemo-resistance. Herein, we assessed microRNA (miRNA) profiling to identify the functional network and biological pathways altered in SPARC-overexpressed medulloblastoma cells. A total of 27 differentially expressed miRNAs were identified between the control and SPARC-overexpressed samples. Potential messenger RNA (mRNA) targets of the differentially expressed miRNA were identified using Ingenuity Pathway Analysis (IPA). Network-based functional analyses were performed on the available human protein interaction and miRNA-gene association data to highlight versatile miRNAs among the significantly deregulated miRNAs using the IPA, and the biological pathway analysis using the PANTHER web-based tool. We have identified six miRNAs (miR-125b1*, miR-146a-5p, miR-181a-5p, miR-204-5p, miR-219-5p and miR-509-3p) that are associated with SPARC sensitivity by comparison of miRNA expression patterns from the SPARC treated cells with the control cells. Furthermore, pathway enrichment analysis outline that these six microRNAs mainly belong to biological processes related to cancer related signaling pathways. Collectively, these studies have the potential to indicate novel biomarkers for treatment response and can also be applied to develop novel therapeutic treatment for medulloblastoma.
| S-EPMC5396623 | biostudies-literature
Project description:New strategies for cancer immunotherapy are needed since most solid tumors do not respond to current approaches. Here we used epithelial cell adhesion molecule EpCAM (a tumor-associated antigen highly expressed on common epithelial cancers and their tumor-initiating cells) aptamer-linked small-interfering RNA chimeras (AsiCs) to knock down genes selectively in EpCAM+ tumors with the goal of making cancers more visible to the immune system. Knockdown of genes that function in multiple steps of cancer immunity was evaluated in aggressive triple-negative and HER2+ orthotopic, metastatic, and genetically engineered mouse breast cancer models. Gene targets were chosen whose knockdown was predicted to promote tumor neoantigen expression (Upf2, Parp1, Apex1), phagocytosis, and antigen presentation (Cd47), reduce checkpoint inhibition (Cd274), or cause tumor cell death (Mcl1). Four of the six AsiC (Upf2, Parp1, Cd47, and Mcl1) potently inhibited tumor growth and boosted tumor-infiltrating immune cell functions. AsiC mixtures were more effective than individual AsiC and could synergize with anti-PD-1 checkpoint inhibition.
| S-EPMC7936362 | biostudies-literature
Project description:Retinoblastoma (RB) is a common pediatric cancer. The study aimed to uncover the mechanisms of RB progression and identify novel therapeutic biomarkers.The miRNA expression profile GSE7072, which includes three RB samples and three healthy retina samples, was used. After data normalization using the preprocessCore package, differentially expressed miRNAs (DE-miRs) were selected by the limma package. The targets of the DE-miRs were predicted based on two databases, followed by construction of the miRNA-target network. Pathway enrichment analysis was conducted for the targets of the DE-miRNAs using DAVID. The CTD database was used to predict RB-related genes, followed by clustering analysis using the pvclust package. The correlation network of DE-miRs was established. MiRNA expression was validated in another data set, GSE41321.In total, 24 DE-miRs were identified whose targets were correlated with the cell cycle pathway. Among them, hsa-miR-373, hsa-miR-125b, and hsa-miR-181a were highlighted in the miRNA-target regulatory network; 14 DE-miRs, including hsa-miR-373, hsa-miR-125b, hsa-miR-18a, hsa-miR-25, hsa-miR-20a, and hsa-let-7 (a, b, c), were shown to distinguish RB from healthy tissue. In addition, hsa-miR-25, hsa-miR-18a, and hsa-miR-20a shared the common target BCL2L11; hsa-let-7b and hsa-miR-125b targeted the genes CDC25A, CDK6, and LIN28A. Expression of three miRNAs in GSE41321 was consistent with that in GSE7072.Several critical miRNAs were identified in RB progression. Hsa-miR-373 might regulate RB invasion and metastasis, hsa-miR-181a might involve in the CDKN1B-mediated cell cycle pathway, and hsa-miR-125b and hsa-let-7b might serve as tumor suppressors by coregulating CDK6, CDC25A, and LIN28A. The miRNAs hsa-miR-25, hsa-miR-18a, and hsa-miR-20a might exert their function by coregulating BCL2L1.
| S-EPMC4688417 | biostudies-literature
Project description:Retinoblastoma (RB) is the most common intraocular tumor in childhood. Long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NTAT1) has been reported to be related to RB progression. This study aims to study the molecular mechanism of NEAT1 in regulating cell cycle, proliferation, apoptosis, migration, and invasion in RB. The expression levels of NEAT1 and miR-3619-5p were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of LIM and SH3 domain protein 1 (LASP1) was measured by western blot. The proliferation of RB cells was analyzed by cell counting kit-8 (CCK-8) and cell colony formation assays. Cell migration and invasion were evaluated by transwell assay. Cell cycle and apoptosis were assessed by flow cytometry analysis. The association between miR-3619-5p and NEAT1 or LASP1 was predicted by starBase 3.0 database and identified by dual-luciferase reporter assay. The effects of NEAT1 knockdown on the tumor growth in vivo were detected by in vivo tumor formation assay. NEAT1 expression was dramatically up-regulated, and miR-3619-5p expression was obviously downregulated in RB tissues and cells compared with control groups. The protein level of LASP1 was obviously increased in RB tissues or cells relative to paracancerous normal tissues or cells, respectively. Functionally, NEAT1 silencing inhibited RB cell migration, invasion, and proliferation, whereas induced cell apoptosis and cell cycle arrest in RB; this phenomenon was partially abolished by miR-3619-5p inhibitor. Mechanistically, NEAT1 acted as a sponge of miR-3619-5p, and miR-3619-5p was associated with LASP1. In addition, NEAT1 knockdown decreased the volume and weight of RB tumor in vivo. Together, NEAT1 silencing repressed cell migration, invasion, and proliferation, whereas induced cell apoptosis and cycle arrest by sponging miR-3619-5p to inhibit LASP1 expression in RB cells. This study may provide a theoretical basis for RB therapy.
| S-EPMC7705249 | biostudies-literature
Project description:Senescence is one of the main barriers against tumor progression. Oncogenic signals in primary cells result in oncogene-induced senescence (OIS), crucial for protection against cancer development. It has been described in premalignant lesions that OIS requires DNA damage response (DDR) activation, safeguard of the integrity of the genome. Here we demonstrate how the cellular mechanisms involved in oncogenic transformation in a model of glioma uncouple OIS and DDR. We use this tumor type as a paradigm of oncogenic transformation. In human gliomas most of the genetic alterations that have been previously identified result in abnormal activation of cell growth signaling pathways and deregulation of cell cycle, features recapitulated in our model by oncogenic Ras expression and retinoblastoma (Rb) inactivation respectively. In this scenario, the absence of pRb confers a proliferative advantage and activates DDR to a greater extent in a DNA lesion-independent fashion than cells that express only HRas(V12). Moreover, Rb loss inactivates the stress kinase DDR-associated p38MAPK by specific Wip1-dependent dephosphorylation. Thus, Rb loss acts as a switch mediating the transition between premalignant lesions and cancer through DDR modulation. These findings may have important implications for the understanding the biology of gliomas and anticipate a new target, Wip1 phosphatase, for novel therapeutic strategies.
| S-EPMC2573954 | biostudies-literature
Project description:PurposeRetinoblastoma (RB) is the most common primary malignant intraocular cancer. The etiology of RB is complex, and the mechanisms driving its progression remain unclear. Here, we used a series of bioinformatics approaches and experimental methods to investigate the potential regulatory mechanism involved in RB progression.MethodsThe common differentially expressed genes were obtained from the public dataset GSE97508. Protein-protein interaction (PPI) network, correlation, and functional enrichment analyses were carried out. The candidate genes were verified in different RB cell lines, and ARPE19 cells served as control. miRNA-mRNA interaction analysis was performed and confirmed by real-time PCR. The CCK-8 assay was conducted to detect cell viability, and the transwell assay was utilized for evaluating the abilities of cell migration and invasion.ResultsOverall, a total of 258 common differentially expressed genes associated with RB progression were screened out. The PPI network analysis further identified eight downregulated genes mainly enriched in the protein ubiquitination pathway. Moreover, we confirmed UBE2E1, SKP1, FBXO9, FBXO15, and RNF14 from among eight genes through experimental validation in vitro. Furthermore, miRNA-mRNA interaction and real-time PCR analysis of five hub genes revealed that ubiquitination-related miR-548k was involved in RB progression. Loss- and gain-of-function experiments demonstrated that miR-548k and its targets were essential for cell viability, migration, and invasion in the RB cells.ConclusionsOur data indicate that the dysregulation of protein ubiquitination may play an important role in RB progression, and ubiquitination-related miR-548k may be a promising therapeutic target for RB.
| S-EPMC8340667 | biostudies-literature
Project description:Skin cutaneous melanoma (SKCM) is the most lethal tumor among three of the major malignant cancers of the skin. The mechanism underlying the malignant biological behaviors of SKCM is not fully clear. Our study intended to verify the molecular mechanism of proteasome 26 S subunit ATPase 2 (PSMC2) in malignant biological behaviors of SKCM. The Cancer Genome Atlas (TCGA) database was used to analyze the expression of PSMC2 in SKCM and its impact on prognosis. PSMC2 expression in 105 paired SKCM tissues was investigated by immunohistochemistry (IHC), its functional roles were verified using a series of cell experiments, and the underlying pathway was detected by protein-chip technology and gene set enrichment analysis. We found that PSMC2 was significantly upregulated in SKCN patients from TCGA datasets and verified in clinical SKCM tissues. Moreover, high PSMC2 was shown to closely correlate with the pathological stages and lymphatic metastasis of SKCM patients. Functionally, knockdown of PSMC2 suppressed the progression of SKCM through inhibiting cell proliferation, migration, and DNA damage in vitro as well as cell growth in vivo, whereas inducing apoptosis, cycle arrest in G2 phase. Similarly, pharmaceutical inhibition of proteasome with MG132 mimicked the PSMC2 knockdown induced defects in cell cycle arrest, apoptosis and proliferation, while overexpression of PSMC2 has the opposite effects. Mechanistically, the silence of PSMC2 remarkably elevated the pro-apoptotic proteins DR6, IGFBP-4, p21, and p53, while inhibited the anti-apoptosis protein TRAILR-3 and the proteins related to the Wnt signaling pathway. The present study revealed that PSMC2 participated in a positive regulation to promote the progression of SKCM through regulating the Wnt signaling pathway. Our findings may offer a new mechanism underlying the development and progression of SKCM, and a deeper understanding of PSMC2 may contribute to SKCM treatment.
| S-EPMC8556233 | biostudies-literature
Project description:EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM(+) CTC detected by CellSearch and EpCAM(-) CTC discarded by CellSearch, after EpCAM based enrichment. EpCAM(-) CTC were identified by filtration and fluorescent labelling. This approach was validated using different cell lines spiked into blood and evaluated on blood samples of 27 metastatic lung cancer patients. The majority of spiked EpCAM(+) cells could be detected with CellSearch, whereas most spiked cells with EpCAM(low) or EpCAM(-) expression were detected using filtration. Five or more CTC were detected in 15% of the patient samples, this increased to 41% when adding the CTC detected in the discarded blood. The number of patients with CTC and the number of CTC detected were doubled by the presence of EpCAM(-) CTC. In this pilot study, the presence of EpCAM(+) CTC was associated with poor outcome, whereas the EpCAM(-) CTC were not. This observation will need to be confirmed in larger studies and molecular characterization needs to be conducted to elucidate differences between EpCAM(-) and EpCAM(+) CTC.
| S-EPMC4505332 | biostudies-literature
Project description:BackgroundThe tumor microenvironment consists of both physical and chemical factors. Tissue elasticity is one physical factor contributing to the microenvironment of tumor cells. To test the importance of tissue elasticity in cell culture, primitive neuroectodermal tumor (PNET) stem cells were cultured on soft polyacrylamide (PAA) hydrogel plates that mimics the elasticity of brain tissue compared with PNET on standard polystyrene (PS) plates. We report the molecular profiles of PNET grown on either PAA or PS.Methodology/principal findingsA whole-genome microarray profile of transcriptional expression between the two culture conditions was performed as a way to probe effects of substrate on cell behavior in culture. The results showed more genes downregulated on PAA compared to PS. This led us to propose microRNA (miRNA) silencing as a potential mechanism for downregulation. Bioinformatic analysis predicted a greater number of miRNA binding sites from the 3' UTR of downregulated genes and identified as specific miRNA binding sites that were enriched when cells were grown on PAA-this supports the hypothesis that tissue elasticity plays a role in influencing miRNA expression. Thus, Dicer was examined to determine if miRNA processing was affected by tissue elasticity. Dicer genes were downregulated on PAA and had multiple predicted miRNA binding sites in its 3' UTR that matched the miRNA binding sites found enriched on PAA. Many differentially regulated genes were found to be present on PS but downregulated on PAA were mapped onto intron sequences. This suggests expression of alternative polyadenylation sites within intron regions that provide alternative 3' UTRs and alternative miRNA binding sites. This results in tissue specific transcriptional downregulation of mRNA in humans by miRNA. We propose a mechanism, driven by the physical characteristics of the microenvironment by which downregulation of genes occur. We found that tissue elasticity-mediated cytokines (TGFβ2 and TNFα) signaling affect expression of ECM proteins.ConclusionsOur results suggest that tissue elasticity plays important roles in miRNA expression, which, in turn, regulate tumor growth or tumorigenicity.
| S-EPMC4361745 | biostudies-literature
Project description:Retinoblastoma (RB; encoded by RB1) is a tumor suppressor that is frequently disrupted in tumorigenesis and acts in multiple cell types to suppress cell cycle progression. The role of RB in tumor progression, however, is poorly defined. Here, we have identified a critical role for RB in protecting against tumor progression through regulation of targets distinct from cell cycle control. In analyses of human prostate cancer samples, RB loss was infrequently observed in primary disease and was predominantly associated with transition to the incurable, castration-resistant state. Further analyses revealed that loss of the RB1 locus may be a major mechanism of RB disruption and that loss of RB function was associated with poor clinical outcome. Modeling of RB dysfunction in vitro and in vivo revealed that RB controlled nuclear receptor networks critical for tumor progression and that it did so via E2F transcription factor 1-mediated regulation of androgen receptor (AR) expression and output. Through this pathway, RB depletion induced unchecked AR activity that underpinned therapeutic bypass and tumor progression. In agreement with these findings, disruption of the RB/E2F/nuclear receptor axis was frequently observed in the transition to therapy resistance in human disease. Together, these data reveal what we believe to be a new paradigm for RB function in controlling prostate tumor progression and lethal tumor phenotypes.
| S-EPMC2993601 | biostudies-literature