Invasion Of Retinoblastoma Cells Research Articles

Retraction: MiR-486-3p inhibits the proliferation, migration and invasion of retinoblastoma cells by targeting ECM1.

This article is being retracted from Bioscience Reports at the request of the Editor-in-Chief and the Editorial Board following receipt of a notification from a reader, alerting the Editorial Board to concerns regarding the western blots and flow-cytometry plots of this manuscript. The western blots have concerning features such as the shapes of the bands and absence of any detectable background, and the flow-cytometry plots of Figure 6E share strong similarities with those found in other papers by unrelated authors, including in Figures 2E and 4F of Li et al. 2019 (https://doi.org/10.1080/15384101.2019.1674071). The authors have been contacted with regards to these concerns and subsequently the retraction, but they have not responded to the Journal's queries or the concerns raised. Given the extent of the issues raised, the Editorial Board stand by the decision to retract the article.

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].

CSIG-33. BCOR LOSS PROMOTES RETINOBLASTOMA GROWTH AND DISSEMINATION BY MODULATING INSULIN-LIKE GROWTH FACTOR 2

Abstract While loss of RB function is the most common genetic alteration in the pediatric embryonal eye tumor retinoblastoma, mutations leading to BCL-6 corepressor (BCOR) loss of function are the second most common alteration. BCOR mutations are found in more aggressive tumors, and are associated with metastasis and poor prognosis. We investigated the effects of BCOR loss or overexpression in retinoblastoma cells in order to better understand its functional role, and to determine if it represents a new therapeutic target in these tumors. Six established retinoblastoma cell lines were examined, and BCOR protein was most highly expressed in WERI-RB1, but absent in Y79 and two other lines. BCOR knock down in WERI-RB1 cells using shRNA caused markedly increased migration and proliferation. BCOR was also knocked out in these cells using CRSPR, resulting in more than three-fold increased size of intraocular murine xenografts and extensive extraocular extension of tumors. In terms of mechanism, BCOR loss of function induces IGF2 transcription, resulting in an activation of IGF1R and the ERK signaling pathway. In contrast, overexpressing BCOR in Y79 retinoblastoma cells with no baseline protein had opposite effects on IGF2. Targeting IGF2/IGF1R signaling pharmacologically using Lincitinib inhibited proliferation and migration in BCOR-negative retinoblastoma cells. Increased IGF2 transcription was regulated at least in part by hyper methylation of CCCTC-binding factor (CTCF)-binding regions in the IGF2/H19 imprinting control region (ICR), suggesting that BCOR knock down promotes increased methylation at this site. In summary, our studies revealed that BCOR loss promotes the growth and invasion of retinoblastoma cells in vitro and in vivo, at least in part via modulating IGF2 transcription, suggesting new potential therapeutic targets for these aggressive childhood tumors of the eye.

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.

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.

TRIB3 promotes proliferation, migration, and invasion of retinoblastoma cells by activating the AKT/mTOR signaling pathway.

Tribbles pseudokinase 3 (TRIB3) is a member of the tribbles-related family, which has been determined in various cancers, including renal cell carcinoma, acute promyelocytic leukemia, colorectal cancer, endometrial cancer, and glioma. However, its role in retinoblastoma (RB) has not yet been explored. The expression level of TRIB3 was detected in RB tissues and cell lines using qRT-PCR. The effects of TRIB3 on cell proliferation and invasion capacities were analyzed with MTT, crystal violet, and transwell assays. Western blot and rescue assays were conducted to explore the underlying mechanism. This study found that TRIB3 was upregulated in human RB tissues compared to adjacent normal tissues both at the mRNA and protein levels. Overexpression of TRIB3 significantly promoted cell proliferation and invasion of RB cells, while TRIB3 knockdown inhibited these processes. Moreover, the mechanism deciphering experiments showed that TRIB3 overexpression can increase AKT and mTOR phosphorylation. Conversely, TRIB3 knockdown decreased the phosphorylation of AKT and mTOR. Additionally, MK2206, a potent AKT inhibitor, blocked the promotive effects of TRIB3 in RB cells. This study demonstrated that TRIB3 acts as an oncogene and plays a crucial role in the proliferation and invasion of RB cells via regulating the AKT/mTOR signaling pathway. Therefore, TRIB3 may serve as a potential target in the diagnosis and/or treatment of RB.

LncRNA CCAT1 sponges miR-218-5p to promote EMT, cellular migration and invasion of retinoblastoma by targeting MTF2

Retinoblastoma (RB) is the primary neoplasms of the retina that is most common in pediatrics age. Long non-coding RNAs (lncRNAs) has been noticed for strong relation to the occurrence and progress of retinoblastoma. Previously, we have demonstrated that lncRNA colon cancer-associated transcript 1 (CCAT1) in two RB cell lines SO-RB50 and Y79 was obviously overexpressed, and notably, lncRNA CCAT1 attenuated miR-218-5p expressionand induced proliferation, cell migration and invasion. But, how lncRNA CCAT1 acts in RB development and the potential molecular mechanisms remain to be determined. In this study, the expression levels of lncRNA CCAT1 and miR-218-5p were evaluated in RB tissues by Q-PCR, which established the results in the cell lines. Further, lncRNA CCAT1 was shown to promote epithelial-to-mesenchymal transition (EMT), cellular migration and invasion of RB cells by functional analysis of downregulation and overexpression of lncRNA CCAT1 with specific siRNA and pcDNA transfection. By performing bioinformatics and dual luciferase reporter assay, we verified the direct interaction between lncRNA CCAT1 and miR-218-5p. Besides, bioinformatics analysis indicated that metal regulatory transcription factor 2 (MTF2) might be a potent novel target for miR-218-5p, which was further validated with luciferase reporter assay, Q-PCR and also Western blot analysis. Functional analysis and rescue analysis showed that lncRNA CCAT1 via competitive binding to miR-218-5p to modulate MTF2 expression thus accelerate EMT, cell migration and invasion of RB. In conclusion, here we identified the lncRNA CCAT1/miR-218-5p/MTF2 axis in RB cell lines. Our investigations on the function of lncRNA CCAT1 and the roles of the related molecules hint a novel potential target fo RB therapy.

LRPPRC regulates metastasis and glycolysis by modulating autophagy and the ROS/HIF1-α pathway in retinoblastoma

Retinoblastoma (RB) is the most common intraocular tumor among children. Leucine-rich pentatricopeptide repeat (PPR)-motif-containing protein (LRPPRC), a suppressor gene of autophagy, has been proven to play a regulatory role in tumor progression. However, little is known about functional roles and mechanisms of LRPPRC in RB progression. First, we performed a detailed analysis for RB and normal control. The expression of LRPPRC in the RB tissues was significantly higher than that in normal tissues. Moreover, LRPPRC suppression could repress tumor cell migration, invasion, glycolysis, and reactive oxygen species (ROS)/hypoxia-inducible factor-1α (HIF1-α) pathway activation by mediating autophagy. Furthermore, overexpression of HIF1-α partially reversed the above changes induced by LRPPRC knockdown. The regulation of LRPPRC on tumor metastasis and glycolysis was also validated by a xenograft tumor assay. In summary, LRPPRC could regulate metastasis and glycolysis of RB by mediating autophagy suppression and further activating the ROS/HIF1-α pathway, and LRPPRC could be a promising prognostic biomarker for RB.

CircTET1 Inhibits Retinoblastoma Progression via Targeting miR-492 and miR-494-3p through Wnt/β-catenin Signaling Pathway

ABSTRACT Purpose: Retinoblastoma (RB) is a frequent intraocular malignancy in children. Circular RNA (circRNA) plays an essential role in regulating the occurrence and development of tumors. This study aimed at investigating the function and molecular basis of hsa_circ_0093996 (circTET1) in RB. Methods: The expression of circTET1, miR-492 and miR-494-3p was examined using quantitative real-time polymerase chain reaction. Cell proliferation, cycle arrest, apoptosis, migration and invasion of RB cells were detected using Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, scratch assay and transwell analysis, respectively. The levels of matrix metalloproteinase (MMP) 2, MMP9 and Wnt/β-catenin pathway-related proteins were measured via western blot assay. The association between circTET1 and miR-492/miR-494-3p was validated via dual-luciferase reporter assay and RNA pull-down assay. Xenograft assay was employed to analyze tumor growth in vivo. Results: CircTET1 level was reduced, while miR-492 and miR-494-3p levels were increased in RB tissues and cells. Overexpression of circTET1 inhibited proliferation, migration and invasion, and promoted apoptosis and cell cycle arrest in Y79 and WERI-Rb1 cells. Moreover, circTET1 impeded RB cell progression by sponging miR-492/miR-494-3p. Also, up-regulation of circTET1 restrained Wnt/β-catenin pathway via regulating miR-492 and miR-494-3p. Furthermore, circTET1 suppressed tumor growth in xenograft models. Conclusion: CircTET1 inhibited RB progression by sponging miR-492/miR-494-3p and inactivating the Wnt/β-catenin pathway, which provided new insights for RB treatment.

Circ_0000527 Promotes Retinoblastoma Progression through Modulating miR-98-5p/XIAP Pathway

ABSTRACT Purpose: Retinoblastoma (RB) is an intraocular malignancy that often occurs in childhood. Circular RNAs (circRNAs) play crucial roles in regulating the malignant phenotypes of various tumors. This study aimed to explore the role and potential mechanism of circ_0000527 in RB. Methods: The levels of circ_0000527, microRNA-98-5p (miR-98-5p) and X-linked inhibitor of apoptosis (XIAP) were determined by qRT-PCR or western blot. Cell proliferation was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and colony formation assays. Cell apoptosis, migration and invasion were evaluated by flow cytometry, transwell and scratch assays. Xenograft assay was conducted to analyze tumor growth in vivo. The binding relationship between miR-98-5p and circ_0000527 or XIAP was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Results: Circ_0000527 and XIAP levels were increased, while miR-98-5p level was reduced in RB tissues and cells. Silencing of circ_0000527 suppressed the proliferation, migration and invasion of RB cells and promoted apoptosis. In addition, knockdown of circ_0000527 inhibited tumor growth in xenograft mice. Besides, circ_0000527 sponged miR-98-5p to regulate RB cell progression, and miR-98-5p targeted XIAP to mediate RB cell development. Moreover, circ_0000527 modulated XIAP expression via sequestering miR-98-5p. Conclusion: Circ_0000527 facilitated RB progression via regulating miR-98-5p/XIAP axis, which provided a promising therapeutic target for RB.

MicroRNA-34b-5p inhibits proliferation, stemness, migration and invasion of retinoblastoma cells via Notch signaling.

Retinoblastoma (RB) is one of the most common forms of childhood intraocular cancer. While the occurrence of RB is traditionally associated with dysregulation of the RB1 gene, efforts have been made to assess the role of several other pathways that may result in RB. The Notch signaling pathway has been identified as one of the sentinel pathways in retinal development and has been indicated to serve as a tumor suppressor. However, epigenetic modifications of the Notch signaling pathway, and their consequences on tumor establishment and progression, have received little attention. The present study attempted to elucidate the microRNA (miR)-mediated dysregulation of the Notch signaling pathway and its implications on tumor initiation. Upon recruitment of patients with RB (age, 4-25 months), the levels of miR-34b-5p were determined in tumor and adjacent healthy tissues. Simultaneously, the serum levels of miR-34b-5p were measured in tumor and healthy samples using reverse transcriptase-quantitative PCR (RT-qPCR). Binding of miR-34b-5p to Notch1 and Notch2 were confirmed bioinformatically. In vitro studies were performed in Y79 and Weri-Rb-1 RB cell lines. The cell lines were transfected with miR-34b-5p constructs and miR-34b-5p overexpression was confirmed using RT-qPCR. The impact of miR-34b-5p overexpression on cell growth and cancer stemness markers (Sox-2, Nanog, and CD133) was examined. The expression levels of Notch1 and Notch2 were evaluated in the presence of miR-34b-5p. The rescue of cell growth and cancer stemness phenotypes was evaluated by co-transfection of miR-34b-5p with Notch1 or Notch2. The results of the present study indicated that the expression levels of miR-34b-5p were reduced in patient tissues and serum samples compared with those in healthy tissues and samples. Notch1 and Notch2 expression level was negatively correlated with the expression level of miR-34b-5p. Overexpression of miR-34b-5p resulted in reduced cell proliferation, migration, invasion and cancer stemness compared with the control group. Further in vivo experiments confirmed the inhibitory effects of miR-34b-5p on RB cell proliferation. Upon co-transfection of miR-34b-5p with Notch1 or Notch2, these phenotypes were rescued with reversal of cell growth and tumor sphere formation. Collectively, the results indicated that miR-34b-5p functions as a tumor suppressor in RB via regulating the Notch signaling pathway. Therefore, miR-34b-5p may be explored for its utility as a therapeutic target in RB.

RRS1 Promotes Retinoblastoma Cell Proliferation and Invasion via Activating the AKT/mTOR Signaling Pathway.

Ribosome biogenesis regulatory protein homolog (RRS1) is a protein required for ribosome biogenesis. Recent studies have identified an oncogenic role of RRS1 in some cancers, whereas the involvement of RRS1 in retinoblastoma (RB) remains to be determined. In this study, we aimed to explore the role of RRS1 in RB. We found that the expression of RRS1 was increased in RB tissues and cells. Lentivirus-mediated RRS1 overexpression promoted the proliferation, growth, and invasion of RB cells. Opposite results were found in RRS1 knockdown cells. In addition, RRS1 silencing induced cell cycle arrest at the G1 phase and apoptosis in RB cells, while RRS1 ectopic expression exhibited the opposite effect. At the molecular level, RRS1 activated the AKT/mTOR signaling pathway, inhibition of which largely blunted the proliferation, growth, and invasion of RB cells. Our study suggests that RRS1 functions as an oncogene in RB through activating the AKT/mTOR signaling pathway.

LncRNA KCNQ1OT1 promotes the proliferation, migration and invasion of retinoblastoma cells by upregulating HIF-1α via sponging miR-153-3p

It is reported that lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) is oncogenic in many cancers. This work aimed at probing into its expression and biological functions in retinoblastoma (RB)...

M6 A methyltransferase METTL3 promotes retinoblastoma progression via PI3K/AKT/mTOR pathway.

Retinoblastoma (RB) is a common intraocular malignancy in children. Due to the poor prognosis of RB, it is crucial to search for efficient diagnostic and therapeutic strategies. Studies have shown that methyltransferase‐like 3 (METTL3), a major RNA N (6)‐adenosine methyltransferase, is closely related to the initiation and development of cancers. Nevertheless, whether METTL3 is associated with RB remains unexplored. Therefore, we investigated the function and mechanisms of METTL3 in the regulation of RB progression. We manipulated METTL3 expression in RB cells. Then, cell proliferation, apoptosis, migration and invasion were analysed. We also analysed the expression of PI3K/AKT/mTOR pathway members. Finally, we incorporated subcutaneous xenograft mouse models into our studies. The results showed that METTL3 is highly expressed in RB patients and RB cells. We found that METTL3 knockdown decreases cell proliferation, migration and invasion of RB cells, while METTL3 overexpression promotes RB progression in vitro and in vivo. Moreover, two downstream members of the PI3K/AKT/mTOR pathway, P70S6K and 4EBP1, were affected by METTL3. Our study revealed that METTL3 promotes the progression of RB through PI3K/AKT/mTOR pathways in vitro and in vivo. Targeting the METTL3/PI3K/AKT/mTOR signalling axis could be a promising therapeutic strategy for the treatment of RB.

CircDHDDS/miR-361-3p/WNT3A Axis Promotes the Development of Retinoblastoma by Regulating Proliferation, Cell Cycle, Migration, and Invasion of Retinoblastoma Cells

Retinoblastoma (RB) is a common intraocular malignant tumor. The growing evidence has reported that circular RNAs (circRNAs) play critical roles in RB development. Therefore, the purpose of the study is to investigate the regulatory mechanism of circDHDDS in RB. The real-time quantitative polymerase chain reaction (RT-qPCR) assay was used to quantify the expression levels of circDHDDS, miR-361-3p, and WNT3A in RB tissues and cells (RPCs, Y-79, and WERI-Rb-1). The proliferation and cell cycle of RB cells were assessed by colony formation assay and flow cytometry assays, respectively. The migration and invasion of RB cells were measured by transwell assay. The protein expression levels of Nectin-3 (CD113), SOX2, Nanog, and WNT3A were measured by Western blot assay. The functional targets of circDHDDS and miR-361-3p were predicted by bioinformatics databases, and the dual-luciferase reporter assay was used to confirm the interaction relationship between miR-361-3p and circDHDDS or WNT3A. The functional role of circDHDDS silencing in vivo was evaluated by xenograft experiment. We found that circDHDDS was overexpressed in RB tissues and cells compared with normal retinas tissues and retinal pigment epithelial cells, correspondingly. Furthermore, silencing of circDHDDS impeded proliferation, migration, invasion, and induced cell cycle arrest in vitro, which were abolished by knockdown of miR-361-3p. The in vivo experiments also suggested that tumor growth was inhibited by knockdown of circDHDDS. Moreover, we also found that miR-361-3p specifically bound to WNT3A, and overexpression of miR-361-3p suppressed RB development by decreasing WNT3A expression. Summarily, circDHDDS, a molecule sponge of miR-361-3p, regulated the expression of WNT3A. Therefore, circDHDDS/miR-361-3p/WNT3A axis stimulated the development of RB by regulation of proliferation, cell cycle program, migration, and invasion of RB cells.

LncRNA LINC00152 Increases the Aggressiveness of Human Retinoblastoma and Enhances Carboplatin and Adriamycin Resistance by Regulating MiR-613/Yes-Associated Protein 1 (YAP1) Axis.

BackgroundLong noncoding RNA (lncRNA) acts as key regulator in human cancers, including retinoblastoma. However, the function of LINC00152 remains largely unknown in retinoblastoma. Thus, this study aimed to explore the role and molecular mechanisms of LINC00152 in retinoblastoma.Material/MethodsThe real-time quantitative polymerase chain reaction (RT-qPCR) was used to quantify the expression levels of LINC00152, miR-613 and yes-associated protein 1 (YAP1). The target genes of LINC00152 and miR-613 were identified by dual-luciferase reporter analysis, RNA immunoprecipitation (RIP) and RNA pulldown assays. The viability, apoptosis, and invasion of retinoblastoma cells were assessed by Cell Counting Kit-8, flow cytometry, and Transwell assays, respectively. In addition, western blot was used to test the protein expression in retinoblastoma cells or tissues. Cell sensitivity to carboplatin and adriamycin was analyzed by computing IC50 value. The effects of LINC00152 silencing in vivo were measured by a xenograft experiment.ResultsLINC00152 was obviously upregulated, while miR-613 was decreased in retinoblastoma tissues and cells. MiR-613, a target of LINC00152, was negatively regulated by LINC00152. Functional experiment further illustrated that silencing of LINC00152 evidently repressed proliferation, invasion, and autophagy while reinforced apoptosis of retinoblastoma cells, besides, retinoblastoma cells were more sensitive to carboplatin and adriamycin after knockdown of LINC00152. Importantly, knockdown of LINC00152-induced effects on retinoblastoma cells could be overturned by introducing miR-613 inhibitor. Downregulation of miR-613 abolished silencing of YAP1-effects on proliferation, apoptosis, invasion, autophagy, and chemoresistance of retinoblastoma cells. The results of the xenograft experiment indicated that LINC00152 silencing impeded tumor growth in vivo.ConclusionsMechanistically, LINC00152 enhanced the aggressiveness of retinoblastoma and boosted carboplatin and adriamycin resistance by regulating YAP1 by sponging miR-613 in human retinoblastoma.

Downregulation of MST4 Underlies a Novel Inhibitory Role of MicroRNA Let-7a in the Progression of Retinoblastoma.

PurposeRetinoblastoma (RB) is the most common intraocular malignancy in children. Deregulation of several microRNAs (miRNAs) has been identified in RB. However, the specific effect of let-7a on RB remains unclear. The present study aims to explore the effect of let-7a on malignant biological behaviors of RB cells and angiogenesis in RB.MethodsThe expressions of let-7a and mammalian sterile-20 like kinase 4 (MST4) in RB were determined with the use of real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Next, in order to explore effects of let-7a and MST4 on RB cellular functions, RB cells were transfected with let-7a-mimic, let-7a inhibitor, si-MST4, or co-transfected with let-7a-mimic and oe-MST4 plasmids. Subsequently, the interaction among let-7a, MST4, and the MAPK signaling pathway was evaluated by RT-qPCR, dual-luciferase reporter gene assay, and Western blot analysis. Finally, the effects of let-7a and MST4 were further confirmed in vivo by injecting nude mice with RB cells stably expressing let-7a agomir or sh-MST4.ResultsRb tissues and cells presented with downregulated Let-7a and upregulated MST4. Let-7a negatively targeted MST4 to block the activation of the MAPK signaling pathway. Upregulation of let-7a promoted apoptosis, and facilitated proliferation, angiogenesis, migration, and invasion of RB cells by decreasing MST4. Elevation of let-7a or silencing MST4 restricted angiogenesis and tumorigenesis in RB mice.ConclusionsTaken together, let-7a inhibits angiogenesis in RB by silencing MST4 and inhibiting the MAPK signaling pathway.

MiR-486-3p inhibits the proliferation, migration and invasion of retinoblastoma cells by targeting ECM1.

It has been reported that miR-486-3p expression is decreased in retinoblastoma (RB) tumor tissues, however, its function in RB has been less reported. The present study aimed to explore the regulatory effects of miR-486-3p on RB cells. The expression of miR-486-3p in RB tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, proliferation, apoptosis, migration and invasion ability were determined by cell counting kit-8 (CCK-8) kit, clone formation assay, flow cytometry, scratch assay and transwell, respectively. Targetscan 7.2 and dual-luciferase reporter were used to verify target genes for miR-486-3p. The expressions of apoptosis-related proteins and ECM1 were detected by Western blot. The miR-486-3p expression was decreased in RB tissues and cells. In RB cells, overexpression of miR-486-3p inhibited cell proliferation, migration and invasion, while promoted apoptosis. Moreover, overexpression of miR-486-3p decreased Bcl-2 expression, while increased the expressions of Bax and Cleaved Caspase-3 (C caspase-3). ECM1 was the target gene of miR-486-3p, and miR-486-3p inhibited the expression of ECM1. Furthermore, ECM1 partially reversed the inhibitory effect of miR-486-3p on the proliferation, migration and invasion of RB cells. MiR-486-3p inhibited the proliferation, migration and invasion of RB by down-regulating ECM1.

Circular RNA has_circ_0000527 participates in proliferation, invasion and migration of retinoblastoma cells via miR-646/BCL-2 axis.

Retinoblastoma (RB) is one of the most common primary intraocular malignancies in children. Emerging researches have shown that circular RNAs (circRNAs) play critical roles in a variety of cancers. As a novel circRNA, the function of circ_0000527 in RB remains unknown. In this work, expression level of circ_0000527 and miR-646 in RB tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). RB cell lines (SO-Rb50 and WERI-Rb-1) were used as cell models in functional experiments. CCK-8 assay, TUNEL assay and transwell assay were employed to detect the biological influence of circ_0000527 and miR-646 on cancer cells in vitro. qRT-PCR, luciferase reporter assay, RIP assay and western blot were used for exploring the interactions among circ_0000527, miR-646 and BCL-2. It was demonstrated that expression level of circ_0000527 in RB samples was significantly up-regulated compared to normal tissues, while miR-646 was markedly down-regulated. Overexpression of circ_0000527 promoted the viability, migration and invasion of RB cells, while miR-646 transfection had the opposite effects. Circ_0000527 sponged miR-646 to regulate the expression of BCL-2. In conclusion, circ_0000527 could promote the development of RB by indirectly modulating BCL-2 via absorbing miR-646. SIGNIFICANCE OF THE STUDY: Expression level of circ_0000527 in RB samples was significantly up-regulated compared to normal tissues, while miR-646 was markedly down-regulated. Overexpression of circ_0000527 promoted the viability, migration and invasion of RB cells, while miR-646 transfection had the opposite effects. Circ_0000527 sponged miR-646 to regulate the expression of BCL-2.

Mechanism of FGF7 gene silencing in regulating viability, apoptosis, invasion of retinoblastoma cell line HXO-Rb44 and angiogenesis.

To explore the mechanism of fibroblast growth factor 7 (FGF7) gene silencing in regulating viability, apoptosis, invasion of retinoblastoma (RB) cell line HXO-Rb44 and angiogenesis. Human normal retinal vascular endothelial cells ACBRI-181 was set as the normal group. The cultured RB cell lines HXO-Rb44 were divided into three groups: the blank group (without plasmid transfection), negative control group (transfection of FGF7 plasmid), and the si-FGF7 group (transfection of FGF7 siRNA plasmid). Quantitative Real Time-Polymerase Chain Reaction and Western blot were used to measure the mRNA and protein expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiopoietin-2 (Ang-2), and proliferating cell nuclear antigen (PCNA) in each group. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell invasion assay, and flow cytometry were used, respectively, to assess cell viability, invasive capability, and cell apoptosis in each group. The mRNA and protein expression of FGF7, Bcl-2, VEGF, bFGF, Ang-2, and PCNA were significantly decreased, and the mRNA and protein expression of Bax were significantly increased in the si-FGF7 group than in the blank group (all p<0.05). Compared with the blank group, the si-FGF7 group had significantly decreased cells invasive capability, cell viability at 48 h and 72 h and proliferation, and significantly increased apoptosis rate (all p<0.05). FGF7 gene silencing can inhibit the viability and invasion of RB cells and the expression of angiogenesis-related factors and can promote RB apoptosis.