Retinoblastoma Cell Proliferation Research Articles

Nitric oxide suppression by secreted frizzled-related protein 2 drives retinoblastoma.

Retinoblastoma is a cancer of the infant retina primarily driven by loss of the Rb tumor suppressor gene, which is undruggable. Here, we report an autocrine signaling, mediated by secreted frizzled-related protein 2 (SFRP2), which suppresses nitric oxide and enables retinoblastoma growth. We show that coxsackievirus and adenovirus receptor (CXADR) is the cell-surface receptor for SFRP2 in retinoblastoma cells; that CXADR functions as a "dependence receptor," transmitting a growth-inhibitory signal in the absence of SFRP2; and that the balance between SFRP2 and CXADR determines nitric oxide production. Accordingly, high SFRP2 RNA expression correlates with high-risk histopathologic features in retinoblastoma. Targeting SFRP2 signaling by SFRP2-binding peptides or by a pharmacological inhibitor rapidly induces nitric oxide and profoundly inhibits retinoblastoma growth in orthotopic xenograft models. These results reveal a cytokine signaling pathway that regulates nitric oxide production and retinoblastoma cell proliferation and is amenable to therapeutic intervention.

MicroRNA-708 suppresses the proliferation, migration, and invasion of human retinoblastoma cells by targeting RAP2B, a member of the RAS oncogene family.

Retinoblastoma generally affects children and causes permanent vision failure or even death. MicroRNAs (miRs) have recently gained much attention during recent years. The miR-708 acts as a tumor suppressor in several human cancers, but the former has not been functionally characterized in human retinoblastoma. The present study was designed to investigate the role of miR-708 in human retinoblastoma. The results showed that miR-708 is significantly (P<0.05) downregulated in retinoblastoma cell lines. MiR-708 overexpression significantly (P<0.05) inhibited retinoblastoma cell growth and proliferation by inducing apoptosis. Furthermore, retinoblastoma cells overexpressing miR-708 exhibited a markedly lower migratory rate and invasiveness compared to negative control cells. The bioinformatics and dual luciferase assay revealed a RAS oncogene family protein, RAP2B, which acts as the regulatory target and functional mediator of the molecular role of miR-708 in retinoblastoma. Together, the present study revealed the tumor suppressor role of miR-708 and pointed to the therapeutic implications of miR-708/RAP2B in the treatment of retinoblastoma.

Retracted] MicroRNA‑874 prohibits the proliferation and invasion of retinoblastoma cells by directly targeting metadherin

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the data showing cell invasion assay experiments in Figs.2C, 4D and 5D were strikingly similar to data that had appeared in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 18: 3099‑3105, 2018; DOI: 10.3892/mmr.2018.9295].

β-asarone attenuates the proliferation, migration and enhances apoptosis of retinoblastoma through Wnt/β-catenin signaling pathway.

β-asarone is the prime component of essential oil extracted from Acori graminei Rhizoma, which plays an inhibitory role in various tumors. Here, we aim to investigate the functions as well as the mechanism of β-asarone in retinoblastoma (RB). RB cell lines SO-Rb50 and HXO-Rb44 were treated with different doses of β-asarone. Then, CCK8 and BrdU experiments were adopted to examine the RB cell proliferation. Wound healing test and Transwell assay were employed to detect cell migration and invasion. RB cell apoptosis was tested by flow cytometry and Western blot. An RB cell xenograft model was constructed on nude mice for testing the role of β-asarone on RB cell growth in vivo. RT-PCR and Western blot were used to determine the effect of β-asarone on Wnt/β-catenin signaling pathway. Furthermore, the Wnt/β-catenin pathway inhibitor PNU-74654 and activator HLY78 were administered to RB cells for confirming the effects of β-asarone in Wnt/β-catenin pathway. In vivo experiment showed that β-asarone attenuated SO-Rb50 cell growth in nude mice. Further research found that β-asarone significantly repressed Wnt/β-catenin canonical pathway activation. Prior inhibition of Wnt/β-catenin pathway abolished the antitumor effects induced by β-asarone. β-asarone exerted antitumor effects in RB cells by inactivating the Wnt/β-catenin signaling pathway.

ADAM10 and ADAM17-Novel Players in Retinoblastoma Carcinogenesis.

A disintegrin and metalloproteinase (ADAM) family proteins, acting as sheddases, are important factors in a number of pathologies, including cancer, and have been suggested as promising therapeutic targets. The study presented focuses on the involvement of ADAM10 and ADAM17 in retinoblastoma (RB), the most common malignant intraocular childhood tumor. A significant correlation between ADAM17 expression levels and RB laterality and RB staging was observed. Levels of ADAM10 or ADAM17 regulating miRNAs miR-145, -152, and -365 were significantly downregulated in RB cell lines, and reduced miR levels with simultaneously upregulated ADAM10 and ADAM17 expression were found in RB patients. The involvement of both ADAMs analyzed in ectodomain shedding of the neuronal cell adhesion molecule L1 (L1CAM), shown to induce pro-tumorigenic effects in RB, was confirmed. Lentiviral ADAM10 and ADAM17 single or ADAM10/17 double knockdown (KD) induced caspase-dependent apoptosis and reduced cell viability, proliferation, growth, and colony formation capacity of RB cells. Moreover, differential phosphorylation of the serine/threonine kinase AKT was observed following ADAM17 KD in RB cells. Chicken chorioallantoic membrane (CAM) assays revealed that ADAM17 and ADAM10/17 depletion decreases the tumorigenic and migration potential of RB cells in vivo. Thus, ADAMs are potential novel targets for future therapeutic RB approaches.

Cordycepin inhibited the retinoblastoma cell proliferation, migration, and invasion as well as lung metastasis via modulating c-Myc/cyclin D1 pathway.

This study aims to investigate cordycepin's effects on the proliferation, migration, and invasion of retinoblastoma (RB) cells and its regulatory mechanism. In this study, it was found that cordycepin inhibited RB cell proliferation, migration, and invasion in vitro, and pulmonary metastasis in vivo. c-Myc was a downstream target of cordycepin, and cordycepin significantly suppressed c-Myc expression, and c-Myc overexpression markedly counteracted the impacts of cordycepin on RB cell proliferation, migration, and invasion. c-Myc was positively correlated with the cell cycle pathway. Cordycepin restrained cyclin D1 expression, and c-Myc overexpression rescued this effect. In conclusion, cordycepin targets the c-Myc/cyclin D1 pathway, thereby suppressing the malignant biological behaviors of RB cells.

Legumain affects the PI3K/AKT tumor progression pathway in retinoblastoma

Known as a common malignant tumor among children, retinoblastoma (RB) is highly malignant and has poor prognosis, damages children's vision and degrades quality of life. To identify a potential molecular mechanism of RB, we conducted this study on legumain (LGMN), which is highly expressed in multiple tumors. In this study, we found that LGMN was significantly upregulated in RB cells and was positively expressed in RB tissues. We confirmed that LGMN overexpression (LGMN-OE) can promote RB cell proliferation and inhibit cell apoptosis through CCK8 experiments and flow cytometry. In addition, real-time quantitative polymerase chain reaction (RT‒qPCR) and Western blot results showed that LGMN-OE could regulate the expression of epithelial-mesenchymal transformation-related genes and proteins, related to tumor invasion and metastasis. Moreover, after LGMN knock down, the result was the opposite., RNA sequence analysis revealed 1159 differentially expressed genes between LGMN-OE and the negative control (NCOE), of which 564 were upregulated and 595 were downregulated. The first 10 genes were verified by RT‒qPCR based on P value and fold change. Interestingly, we found that LGMN could regulate the expression of recoverin (RCVRN)through a gene responsible for cancer-related retinopathy. We also screened and verified that LGMN partially activated the PI3K/AKT pathway in RB. Furthermore, we evaluated the effect of legumain inhibitors (e.g., esomeprazole) on RB, and the results suggest that esomeprazole may provide a reference for the clinical adjuvant treatment of RB. In conclusion, legumain can serve as an attractive target for RB therapy and hopefully provide new insights and ideas for the development of targeted drugs and precise personalized clinical therapy.

Wedelolactone induces apoptosis and pyroptosis in retinoblastoma through promoting ROS generation

Retinoblastoma is a most frequently occurring primary intraocular tumor in infancy and children, highlighting the requirement to find and develop novel and more effective therapeutic approaches. Wedelolactone (WDL), a nature compound isolated from E. prostrata, exhibits multiple biological activities through regulating various signaling pathways; however, its potential influences on retinoblastoma progression are still unknown, and thus was investigated in our study, as well as the underlying mechanisms. Here, we found that WDL treatments significantly reduced the proliferation of retinoblastoma cells by inducing apoptosis and pyroptosis through increasing Caspase-3, Caspase-1, gasdermin E (GSDME) and gasdermin D (GSDMD) activation. Mitochondrial impairment and reactive oxygen species (ROS) generation were considerably up-regulated in WDL-incubated retinoblastoma cells through a dose-dependent manner. Notably, we found that ROS scavenge significantly abolished the function of WDL to provoke apoptosis and pyroptosis in retinoblastoma cell lines, revealing that ROS was required for WDL to perform its anti-cancer role in retinoblastoma. Moreover, our in vivo experiments indicated that WDL administration significantly reduced the tumor growth in the established retinoblastoma mouse models with undetectable toxicity. Collectively, these findings highlighted the potential of WDL to inhibit the growth and induce cell death of retinoblastoma in vitro and in vivo, and thereby showed promise as a therapeutic agent for the treatment of retinoblastoma.

UBE2T is a prognostic biomarker and correlated with Th2 cell infiltrates in retinoblastoma

ObjectiveThis study aimed to screen anaplasia-related genes that influence the progression of retinoblastoma (RB) and to identify immune cells associated with the poor prognosis. MethodsDifferentially expressed genes (DEGs) between retina and RB samples were acquired from gene expression omnibus (GEO) database. Candidate hub genes were screened by taking intersections among the co-expressed genes, the hub nodes, and DEGs of the validation set. The hub genes were identified by receiver operating characteristic (ROC) and quantitative real-time PCR (qPCR). Immune infiltration levels of RB tissues were estimated using single-sample gene set enrichment analysis (ssGSEA). The functions of RB cells were detected by CCK8, EDU and flow cytometry assays. Results665 DEGs involved in the genesis and progression of RB were acquired from GEO database. 29 candidate hub genes were screened by examining 43 co-expressed genes and 63 hub nodes. 9 hub genes (CHEK1, EXO1, FANCI, GTSE1, MELK, MKI67, NCAPH, PRC1, and UBE2T) strongly related to the anaplastic grades were validated by ROC curve analysis (AUC >0.8). Based on the ssGSEA scores, the immune infiltration levels of Th2 cells were positively associated with anaplastic grade. qPCR assay showed that 9 hub genes were upregulated in RB cells, and UBE2T expressed remarkably high. CCK 8, EDU, and flow cytometry assays revealed that UBE2T silencing inhibited the proliferation of RB cells and incited apoptosis. ConclusionsThe increased infiltration of Th2 cells and upregulated expression of 9 hub genes predict a poor prognosis of RB. UBE2T can be a therapeutic target for RB treatment.

Circ_0075804 Regulates the Expression of LASP1 by Targeting miR-1287-5p and Thus Affects the Biological Process of Retinoblastoma

Purpose Increasing evidence reveals that circular RNA (circRNA) dysregulation is involved in retinoblastoma (RB) pathogenesis. To further realize the development of RB, we investigated the role and regulatory mechanism of circ_0075804 in RB. Methods Real-time quantitative PCR (RT-qPCR) and western blot were employed for expression analysis. CCK-8 assay, EdU assay, colony formation assay, flow cytometry assay and transwell assay were performed to monitor cell phenotypes. Xenograft models were established to monitor the role of circ_0075804 on tumor growth. Tumor growth was assessed by the expression of Ki67, N-cadherin, MMP2 and MMP9 via IHC assay. The predicted binding sites between miR-1287-5p and circ_0075804 or LIM and SH3 protein 1 (LASP1) were validated by dual-luciferase reporter assay. Results Upregulation of circ_0075804 and LASP1, and downregulation of miR-1287-5p were shown in RB tissues and cells. Circ_0075804 knockdown repressed RB cell growth, invasion and survival, and hindered tumor development in vivo. MiR-1287-5p was targeted by circ_0075804, and its repression largely reversed the functional effects of circ_0075804 knockdown. LASP1 was a functional target of miR-1287-5p. The inhibition of miR-1287-5p upregulation on RB cell proliferation, survival and invasion was reversed by LASP1 overexpression. Moreover, circ_0075804 knockdown weakened LASP1 expression via increasing miR-1287-5p. Conclusion Circ_0075804 promotes LASP1 expression by targeting miR-1287-5p, thus acting as a contributor to RB carcinogenesis. Highlights Circ_0075804 is overexpressed in RB. Circ_0075804 knockdown inhibits RB cell malignant phenotypes and tumor growth in vivo. Circ_0075804 regulates RB cell behaviors by targeting miR-1287-5p. MiR-1287-5p affects RB cell behaviors by binding to LASP1. Circ_0075804 regulates LASP1 expression via targeting miR-1287-5p.

SP2509, a Selective Inhibitor of LSD1, Suppresses Retinoblastoma Growth by Downregulating β-catenin Signaling.

PurposeTo study the role of lysine-specific demethylase 1 (LSD1) in retinoblastoma (RB) growth and to determine whether the LSD1 inhibitor SP2509 can inhibit RB progression.MethodsWe detected the levels of LSD1 in 12 RB tissue samples, two RB cell lines (Y79 and Weri-RB1), and a retinal pigment epithelium cell line (ARPE-19). Overexpression or knockdown of LSD1 was performed to examine the role of LSD1 in RB cancer cell survival. In vitro and in vivo experiments were conducted to detect the antitumor effect of SP2509, and the antitumor mechanism of SP2509 was examined by RNA sequencing and Western blot.ResultsLSD1 is overexpressed in RB tissues and cells and increases RB cancer cell viability and colony formation ability. The LSD1 inhibitor SP2509 inhibits RB cell proliferation in vitro and in vivo. Treatment with SP2509 increases the levels of dimethylated histone 3 lysine 4 (H3K4me2) and inhibits the expression of β-catenin signaling pathway–related proteins in RB cells.ConclusionsWe demonstrated that LSD1 is overexpressed in RB cells and promotes RB cell survival. The LSD1 inhibitor SP2509 exerted strong growth inhibition in vitro and in vivo, which was at least partially mediated by suppression of the β-catenin pathway.

LncRNA MIR17HG promotes the proliferation, migration, and invasion of retinoblastoma cells by up-regulating HIF-1α expression via sponging miR-155-5p.

Long non-coding RNA (lncRNA) miR-17-92a-1 cluster host gene (MIR17HG) is oncogenic in several cancers. This study was aimed to probe into its expression characteristics and biological functions in retinoblastoma (RB) and to explore its role in regulating microRNA-155-5p (miR-155-5p) and hypoxia-inducible factor-1α (HIF-1α). In this study, paired RB samples were collected, and expression levels of MIR17HG, miR-155-5p, and HIF-1α were examined by quantitative real-time polymerase chain reaction (qRT-PCR); the proliferation, migration, and invasion of RB cells were detected by cell counting kit-8 (CCK-8) and transwell assays; qRT-PCR and Western blot were used to analyze the changes of miR-155-5p expression and HIF-1α expression. We found that MIR17HG expression was significantly up-regulated in RB samples, which was negatively correlated with miR-155-5p expression. The proliferation, migration, and invasion of RB cells were promoted by MIR17HG overexpression but inhibited by MIR17HG knockdown. MiR-155-5p suppressed the proliferation, migration, and invasion of RB cells. MIR17HG positively regulated the expression of HIF-1α on both mRNA and protein levels in RB cells. Additionally, miR-155-5p was identified as a target of MIR17HG. The data in this study suggest that MIR17HG exerts oncogenic effects in RB via the miR-155-5p/HIF-1α axis.

Retraction

Retraction: “PRC1 gene silencing inhibits proliferation, invasion, and angiogenesis of retinoblastoma cells through the inhibition of the Wnt/β‐catenin signaling pathway,” by Yu‐Jun Liao, Xiao‐Long Yin, Yan Deng, Xiao‐Wei Peng, J Cell Physiol. 2019, 16840‐16852: The above article, published online on 29 May 2019 in Wiley Online Library (doi:10.1002/jcb.28942) has been retracted by agreement between the authors, the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC.The retraction has been agreed after the authors stated that unintentional errors occurred during the research process, and the experimental results cannot be verified. Thus, the conclusions are considered to be invalid.

AFAP1 antisense RNA 1 promotes retinoblastoma progression by sponging microRNA miR-545-3p that targets G protein subunit beta 1

ABSTRACT The oncogenic role of actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been reported in retinoblastoma (RB). However, the underlying regulatory mechanisms remain poorly understood. In this study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting were performed to analyze the expression of AFAP1-AS1, microRNA miR-545-3p, or G protein subunit beta 1 (GNB1). Cell Counting Kit-8 (CCK-8) and Transwell migration assays were used to detect cell proliferation and migration. In addition, caspase-3 activity was monitored by caspase-3 activity assay. Luciferase reporter assays combined with RNA immunoprecipitation (RIP) and pull-down assays were performed to elucidate the target relationship between miR-545-3p and AFAP1-AS1 or GNB1. Xenograft tumor experiments were performed to evaluate RB cell growth in vivo. Increased AFAP1-AS1 and GNB1 expression in RB tissues and cells was confirmed by RT-qPCR; conversely, miR-545-3p was found to be downregulated in RB tissues and cells. AFAP1-AS1 overexpression resulted in increased proliferation and migration of RB cells, whereas AFAP1-AS1 silencing resulted in decreased proliferation and migration of RB cells. Moreover, AFAP1-AS1 was found to target miR-545-3p. The anti-miR-545-3p treatment phenocopied the effect of AFAP1-AS1 overexpression and promoted RB cell growth in vivo. miR-545-3p was found to directly target GNB1. GNB1 silencing resulted in reduced proliferation and migration of RB cells and attenuated the oncogenic effect of the miR-545-3p inhibitor. Thus, in this study, a novel ceRNA regulation network of AFAP1-AS1 in RB was identified, where AFAP1-AS1 regulated GNB1 expression by targeting miR-545-3p, ultimately driving RB progression.

Kruppel-like factor 2 acts as a tumor suppressor in human retinoblastoma

Krüppel-like factor 2 (KLF2) belongs to the KLF family of zinc-finger transcription factors and mediates the occurrence and progression of various cancers. However, little is known about its expression pattern and biological role in retinoblastoma (RB). In the present study, we showed that KLF2 was markedly downregulated in human RB tissue compared with retina. KLF2 overexpression significantly inhibited RB cell proliferation and decreased proliferating cell nuclear antigen (PCNA) expression. Subsequently, we confirmed that KLF2 arrested cells at the G1-S phase transition, accompanied by the upregulation of p21 and downregulation of CyclinD1, as well as the activation of mitochondria-mediated apoptosis in RB cells. In addition, KLF2 overexpression contributed to suppressing RB cell migration and invasion by downregulating matrix metallopeptidase 9 (MMP9). On the contrary, KLF2 downregulation promoted RB cells proliferation, migration and invasion. Notably, the KLF2 expression pattern was opposite to that of C-X-C chemokine receptor 4 (CXCR4) in the two RB cell lines, KLF2 overexpression significantly decreased CXCR4 expression, silencing KLF2 had the opposite effect. Furthermore, dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays confirmed that KLF2 directly bound to the CXCR4 promoter and negatively regulated its expression in RB cells. Collectively, our results suggested that KLF2 function as a tumor suppressor in RB and may represent a potential therapeutic target for RB.

LncRNA ZFPM2-AS1 Enhances Retinoblastoma Development by Targeting the miR-3612/NT5E Signaling Axis.

Background - Retinoblastoma (RB) is an intraocular malignancy usually observed in children. The zinc finger protein, FOG family member 2 (ZFPM2)-antisense RNA 1 (AS1), an anomalous long non-coding RNA, is detected in many cancers. This study aimed to evaluate the role and underlying mechanism of ZFPM2-AS1 in RB. Methods - ZFPM2-AS1, 5'-nucleotidase ecto (NT5E), and microRNA (miR)-3612 expression levels were determined in RB cells and tissues. Multiple experiments, including cell counting kit-8, 5'-bromo-2'-deoxyuridine, transwell, and enzyme-linked immunosorbent assays, were conducted to evaluate their effects on cell proliferation, migration, and apoptosis. Additionally, the ZFPM2-AS1/miR-3612/NT5E axis was validated using luciferase reporter, anti-AGO2 RNA immunoprecipitation, and RNA pull-down assays. Results - Overexpression of ZFPM2-AS1 and NT5E and downregulation of miR-3612 expression levels were observed in RB cells and tissues. Knockdown of ZFPM2-AS1 decreased the proliferation and migration of RB cells, while enhancing their apoptosis. The ZFPM2-AS1/miR-3612/NT5E axis was further supported by the negative correlation between miR-3612 expression levels and ZFPM2-AS1 or NT5E expression levels in RB tissues. Moreover, the miR-3612 inhibitor restored the inhibitory effect on the malignant behavior of RB cells by silencing ZFPM2-AS1. Furthermore, NT5E silencing phenocopied the effect of ZFPM2-AS1 silencing and abolished miR-3612 inhibitor-induced stimulation of the malignant behavior of RB cells. Conclusion - These results suggest that by targeting the miR-3612/NT5E axis, ZFPM2-AS1 stimulates the proliferation and migration of RB cells, while inhibiting their apoptosis. Therefore, ZFPM2-AS1 may be a promising therapeutic target associated with RB development.

MicroRNA-181a-5p impedes the proliferation, migration, and invasion of retinoblastoma cells by targeting the NRAS proto-oncogene

ObjectivesAccumulating research have reported that microRNAs (miRNAs) play important roles in Retinoblastoma (RB). Nonetheless, the function and underlying mechanism of miR-181a-5p in RB remain ambiguous. MethodsThe relative expression levels of miR-181a-5p and NRAS mRNA were detected by quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). RB cell proliferation was measured using the Cell Counting Kit-8 (CCK-8) and 5′-Bromo-2′-deoxyuridine (BrdU) assays. Transwell assays and flow cytometry were performed to detect the migration, invasion, and apoptosis of RB cells. The interaction between miR-181a-5p and NRAS was explored using luciferase experiments, western blotting, and qRT-PCR. ResultsmiR-181a-5p expression was found to be decreased in RB tissues and cell lines, and its expression was correlated with unfavorable pathological features of the patients. In vitro experiments revealed that miR-181a-5p reduced RB cell proliferation, migration, and invasion while enhancing apoptosis. Further research confirmed that NRAS is a direct target of miR-181a-5p. miR-181a-5p inhibited NRAS expression at both the mRNA and protein levels. Co-transfection of pcDNA-NRAS or NRAS small interfering RNA (siRNA) reversed the effects of miR-181a-5p mimics or miR-181a-5p inhibitors on RB cells. ConclusionmiR-181a-5p was significantly downregulated during the development of RB, and it suppressed the malignant behaviors of RB cells by targeting NRAS.

Knockdown of the Long Noncoding RNA TUG1 Suppresses Retinoblastoma Progression by Disrupting the Epithelial–Mesenchymal Transition

Taurine-upregulated gene 1 (TUG1) is a long noncoding RNA (lncRNA) that has previously been linked to the development and progression of several cancer types. Its expression and mechanistic role in retinoblastoma (RB), however, remains to be established. Herein, we found that RB tissue samples exhibited TUG1 upregulation. RB cell lines similarly exhibited marked TUG1 upregulation. Real-time cellular analysis (RTCA) and colony formation assays were then used to gauge RB cell proliferation, while transwell assays were conducted to assess the metastatic and invasive potential of these cells. In these assays, TUG1 upregulation was found to promote RB cell proliferative, migratory, and invasive activity while inducing the epithelial–mesenchymal transition (EMT). Subsequent quantitative real-time polymerase chain reaction (qPCR) and Western blotting indicated that this lncRNA functions at least in part by influencing the expression of Notch signaling pathway genes, which were downregulated following TUG1 knockdown in RB cells. Together, these data suggested that TUG1 can promote RB cell malignancy via the Notch signaling and EMT pathways, contributing to negative patient outcomes.

Xanthatin Selectively Targets Retinoblastoma by Inhibiting the PLK1-Mediated Cell Cycle.

PurposeRetinoblastoma is the most common primary intraocular malignant tumor in children. Although intra-arterial chemotherapy and conventional chemotherapy have become promising therapeutic approaches for advanced intraocular retinoblastoma, the side effects threaten health and are unavoidable, making the development of targeted therapy an urgent need. Therefore, we intended to find a potential drug for human retinoblastoma by screening an in-house compound library that included 89 purified and well-characterized natural products.MethodsWe screened a panel of 89 natural products in retinoblastoma cell lines to find the inhibitor. The inhibition of the identified inhibitor xanthatin on cell growth was detected through half-maximal inhibitory concentration (IC50), flow cytometry assay, and zebrafish model system. RNA-seq further selected the target gene PLK1.ResultsWe reported the discovery of xanthatin as an effective inhibitor of retinoblastoma. Mechanistically, xanthatin selectively inhibited the proliferation of retinoblastoma cells by inducing cell cycle arrest and promoting apoptosis. Interestingly, xanthatin targeted PLK1-mediated cell cycle progression. The efficacy of xanthatin was further confirmed in zebrafish models.ConclusionsCollectively, our data suggested that xanthatin significantly inhibited tumor growth in vitro and in vivo, and xanthatin could be a potential drug treatment for retinoblastoma.

Long non-coding RNA (lncRNA) five prime to Xist (FTX) promotes retinoblastoma progression by regulating the microRNA-320a/with-no-lysine kinases 1 (WNK1) axis

ABSTRACT Long non-coding RNA (lncRNA) five prime to Xist (FTX) exerts important functions in human cancer, while its role in retinoblastoma (RB) remains unclear. This study aimed to investigate the role of FTX in RB. The expression levels of FTX were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by cell counting kit-8 (CCK-8), 5‐ethynyl‐2′‐deoxyuridine (EdU) staining and colony formation assays. Cell migration and invasion were detected by Transwell assay. The relationship among FTX, microRNA-320a (miR-320a) and with-no-lysine kinase 1 (WNK1) was also investigated. In the present study, we found that the expression levels of FTX were notably elevated in RB tissues and cancer cell lines. Overexpression of FTX exacerbated the aggressive phenotypes (cell proliferation, migration and invasion) of RB cells. Downregulation of miR-320a obviously attenuated the inhibitory effects of knockdown of FTX in RB malignant phenotypes, and knockdown of WNK1 also reversed the impacts of miR-320a inhibitor on malignant phenotypes. In vivo experiments further confirmed that knockdown of FTX efficiently prevents tumor growth in vivo. Our results revealed that FTX promoted RB progression by targeting the miR-320a/WNK1 axis (graphical abstract), suggesting that FTX might be a novel therapeutic target for RB.