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Glioblastoma (GBM) remains one of the most aggressive and lethal brain tumours, characterized by rapid progression and limited treatment options. This study investigated the regulatory roles of circular RNA circJUN, and its functional interaction with microRNA miR-3064 in GBM pathogenesis. We employed bioinformatic analyses and clinical sample validation to identify circJUN as a potential target in GBM. Subsequently, we engineered GBM cell lines with stable circJUN knockout or overexpression, and transfected them with miR-3064 mimic/inhibitor or IGFBP5 small interfering RNA (siRNA)/expression vector to elucidate the molecular mechanisms governing GBM proliferation and invasion. To investigate the in vivo effects, xenograft tumour models were established in nude mice using engineered cells to assess the roles of circJUN in tumour growth regulation. Our analyses revealed significant overexpression of circJUN in GBM tissues compared to healthy controls, which strongly correlated with poor patient prognosis. In vitro and in vivo experiments demonstrated that circJUN overexpression could enhance GBM cell proliferation and invasion. Mechanistic investigations uncovered EIF4A3 as an interacting factor of circJUN which promotes circJUN expression, and circJUN modulates miR-3064 activity to regulate the malignancy of GBM cells. Furthermore, we identified IGFBP5, a crucial regulator of cell growth, as a direct target of miR-3064, thereby establishing an additional layer of control over GBM proliferation and invasion. Our study unveils a complex regulatory network involving circJUN, miR-3064 and IGFBP5 in GBM pathogenesis, underscoring their potential as novel therapeutic targets for improving patient outcomes. Our findings not only contribute to the understanding of GBM biology but also pave the way for innovative therapeutic approaches in the management of this malignancy., (© 2024 The Author(s). Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

SOX9, as a transcript factor, has been confirmed to boost proliferation and epithelial-mesenchymal transition (EMT) of hepatocellular carcinoma (HCC), but the underlying mechanism remains incompletely elucidated. A bioinformatics analysis web, Jaspar, manifested that SOX9 can transcriptionally regulate an lncRNA, MKLN1-AS. To determine the role of MKLN1-AS in HCC, this study measured MKLN1-AS expression in HCC and the paracancerous tissues and conducted a series of assays, including MTT, colony formation, and transwell assays, in vitro. EMT of HCC was evaluated by E-cadherin and vimentin protein levels. The regulatory effect of SOX9 on MKLN1-AS was determined using dual luciferase reporter and ChIP assays. Both MKLN1-AS and SOX9 were up-regulated in HCC tissues compared to paracancerous tissues. SOX9 promoted cell viability, proliferation, invasion, and EMT of HCCs, but these promoting effects of SOX9 were attenuated after the knockdown of MKLN1-AS. Overexpression of SOX9 increased MKLN1-AS in HCCs, whereas silencing SOX9 decreased MKLN1-AS expression. According to dual luciferase reporter and ChIP assays, SOX9 can bind to the promoter of MKLN1-AS gene to stimulate the expression. MKLN1-AS is transcriptionally regulated by SOX9 and mediates the effects of SOX9 on the proliferation and EMT of HCCs., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Cholangiocarcinoma (CCA) is a highly aggressive and malignant tumor. In this study, the effect and molecular mechanism of nuclear enriched abundant transcript 1 (NEAT1) in CCA were elucidated. The expressions of NEAT1, microRNA-186-5p (miR-186-5p), and PTP4A1 were measured by quantitative real-time PCR. The protein levels were measured by Western blotting. Kaplan-Meier analysis was performed to create survival curves. The interactions between NEAT1, miR-186-5p, and PTP4A1 were assessed through the dual luciferase reporter assay. Additionally, the cell proliferation, apoptosis, migration, and invasion were measured by colony formation, flow cytometry, the Transwell assay, and the wound healing assay, respectively. NEAT1 and PTP4A1 were significantly upregulated in CCA tissues and cells, but miR-186-5p was downregulated. NEAT1 expression was negatively correlated with the survival of CCA patients and has remarkable correlation with serum CA199 levels and lymph node metastasis. Besides, NEAT1 could act as a molecular sponge for miR-186-5p to upregulate PTP4A1 expression. More importantly, the knockdown of NEAT1 or overexpression of miR-186-5p inhibited the proliferation, migration and invasion of CCA cells, and the inhibition of miR-186-5p reversed the effects of the knockdown of NEAT1. In addition, NEAT1 could also activate the PI3K/AKT signaling pathway and regulate the epithelial-mesenchymal transition (EMT) through the miR-186-5p/PTP4A1 axis. In conclusion, NEAT1 was involved in cell proliferation, migration and invasion in CCA, and the NEAT1/miR-186-5p/PTP4A1/PI3K/AKT axis indicated novel regulatory mechanisms and therapeutics for the treatment of CCA., (© 2021 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia on behalf of Kaohsiung Medical University.)

Objective: It is reported that circular RNA plays an important role in various cancers in recent years. However, there is less investigation reported in lung adenocarcinoma (LUAD) about circRNA. This study aims to explore the role and molecular mechanism of circle RNA FOXP1 in LUAD procession., Patients and Methods: The levels of circFOXP1 and miR-185-5p in LUAD cell lines and LUAD cancer samples were examined by RT-PCR. The functions of circFOXP1 and miR-185-5p at LUAD cells were detected by cell transfection of the overexpression or repression. The A549 and H1299 cell proliferation were detected by MTT assay and colony formation assay. And the cell apoptosis was detected by TUNEL assay. The expression levels WNT1 were measured by Western blot in A549 and H1299 cells. Furthermore, the luciferase assay detected the direct interaction between circFOXP1 and miR-185-5p or miR-185-5p and WNT1., Results: The circFOXP1 expression was increased in LUAD patients and LUAD cell lines. The downregulation of circFOXP1 significantly repressed LUAD cell proliferation and promoted cell apoptosis. Moreover, the luciferase assay results confirmed that circFOXP1 directly interacted with miR-185-5p. Overexpression of miR-185-5p could reverse the effect of circFOXP1 in LUAD cell. Besides, the luciferase results showed that miR-185-5p directly interacted with WNT1. miR-185-5p overexpression inhibited the WNT1 expression, while circFOXP1 repression decreased the WNT1 level in LUAD cell lines. The downregulating WNT1 could reverse the effects of miR-185-5p inhibition in LUAD cell lines. Furthermore, WNT1 was significantly upregulated in LUAD cancer tissues. In addition, circFOXP1 level was negatively correlated with miR-185-5p expression and positively correlated with WNT1 expression in LUAD cancer tissues., Conclusions: These data suggested that circFOXP1 promoted cell proliferation and repressed cell apoptosis in LUAD by regulating miR-185-5p/WNT1 signaling pathway. It provides a novel potential therapeutic agent for the treatment of LUAD.

Leptin is an adipokine minimally known for its activities or underlying mechanisms in cholangiocarcinoma. The present study explored the effects of leptin on the epithelial‑mesenchymal transition (EMT) and pro‑angiogenic capability of cholangiocarcinoma cells, and investigated the underlying mechanisms. Cholangiocarcinoma cells were treated with leptin, and their migration and invasion rates were investigated using Transwell assays. Furthermore, conditioned medium was collected from cholangiocarcinoma cells following leptin treatment and applied to human umbilical vein endothelial cells to assess tube formation. The expression of EMT and pro‑angiogenic factors was examined by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analyses. Mechanistically, the function of pyruvate kinase muscle isozyme M2 (PKM2) was assessed in leptin‑induced phenotypes using siRNA targeting PKM2 (si‑PKM2). Bioinformatics screening and luciferase reporter assays were used to reveal microRNA (miR)‑122 as the potential mediator between leptin and PKM2. Finally, the associations between leptin and miR‑122 or PKM2 levels in patients with cholangiocarcinoma were assessed by ELISA and RT‑qPCR. Leptin significantly increased the EMT and pro‑angiogenic capability of cholangiocarcinoma cells, visibly inhibited endogenous miR‑122 expression, and upregulated PKM2. Furthermore, si‑PKM2 inhibited leptin‑induced migration, invasion, EMT‑associated marker expression levels and the pro‑angiogenic capability in cholangiocarcinoma cells. In addition, miR‑122 negatively regulated the expression of PKM2. When applied together with leptin, miR‑122 was sufficient to reverse the multiple malignancy‑promoting effects of leptin. Consistently, the serum leptin level positively correlated with that of PKM2, but negatively with that of miR‑122 in patients with cholangiocarcinoma. Leptin, by downregulating miR‑122 and elevating PKM2 expression, acts as a pleiotropic pro‑malignancy cytokine for cholangiocarcinoma. Therefore, increasing miR‑122 expression and inhibiting PKM2 may be future approaches for cholangiocarcinoma treatment.

Objective To investigate the expressions,roles,and clinical significance of microRNA-365(miR-365)and E74-like factor 4(ELF4)in cervical cancer. Methods The expressions of miR-365 in normal cervical tissues(n=34),cervical intraepithelial neoplasia 1(CIN 1)(n=31),cervical intraepithelial neoplasia2-3(CIN 2-3)(n=37),squamous cell carcinoma of the cervix(SCC)(n=33),and three cervical cancer cell lines(C33A cells,Hela cells,and SiHa cells)were detected by real-time quantitative polymerase chain reaction(qPCR).Bioinformatic prediction and luciferase reporter gene assay were performed to verify whether ELF4 was a direct target of miR-365.Western blot and immunohistochemistry were used to detect ELF4 expression in cervical cancer cells and in different pathological cervix tissues.CCK8 assay was used to detect the effect of overexpression or inhibition of miR-365 on the proliferation of cervical cancer cells at different time points.The relationships among the miR-365 expression,ELF4 expression,and clinicopathological parameters of cervical cancer were analyzed by correlation analysis. Results qPCR results showed that compared with the normal cervical cell HcerEpic,the expressions of miR-365 in CIN1,CIN2-3,and cervical cancer tissues gradually decreased with the increased pathologic grade,and its expressions also decreased in different cervical cancer cell lines.The luciferase reporter gene assay confirmed that ELF4 was the direct target of miR-365.Western blot showed that the expression of ELF4 increased in all three cervical cancer cell lines compared with normal cervical epidermal cell(P=0.013,P=0.002,P=0.004).Immunohistochemistry showed that ELF4 expression was up-regulated in CIN and cervical cancer tissues.CCK8 assay showed that overexpression of miR-365 inhibited cell proliferation,while inhibition of miR-365 promoted the proliferation of three cervical cancer cells(P<0.05).Further analysis confirmed that there was a negative correlation between the expression levels of miR-365 and ELF4 in CIN2-3 and SCC(r=-0.351,P=0.045;r=-0.349,P=0.035).Clinical analysis showed that the expressions of both miR-365 and ELF4 were correlated with tumor size,pathological grade,and clinical stage in SCC(all P < 0.05). Conclusion The decreased expression of miR-365 in human cervical cancer cells relieves its inhibitory effect on ELF4,which promotes the proliferation of cervical cancer cells and the formation of tumor.

BACKGROUND Long non-coding RNAs (lncRNAs) have been implicated in various human cancer types. However, the underlying mechanisms involved in hepatocellular carcinoma (HCC) progression remain poorly understood. MATERIAL AND METHODS In this study, lncRNA array was used to identify HCC related lncRNAs. RNA immunoprecipitation (RIP) followed mass spectrometry was used to explore lncRNA binding proteins. Western blot, quantitative PCR, tumor sphere formation, migration and viability assay were performed to evaluate the oncogenic role of lncRNAs. RESULTS We identified a novel lncRNA named long stress induced non-coding transcripts 5 (LSINCT5) which facilitates HCC progression. LSINCT5 was significantly upregulated in both HCC specimens and cell lines and correlates with poor survival. In vitro experiments showed that LSINCT5 promoted migration and viability of HepG2 and Huh7 cells. The in vivo xenograft mouse model also confirmed an oncogenic role for LSINCT5. RIP in combination with mass spectrometry identified HMGA2 as the LSINCT5 binding partner. LSINCT5 could bind to HMGA2 and decrease proteasome-mediated HMGA2 degradation leading to EMT activation. LSINCT5 also served as a competing endogenous RNA (ceRNA) for miR-4516, resulting in increased STAT3/BclxL expression and attenuated apoptosis. CONCLUSIONS Our data have collectively established a lncRNA LSINCT5 mediated process during HCC carcinogenesis and might have provided novel insight into therapeutic targeting.

Long non-coding RNA HOTAIR was regarded as an oncogene in multiple cancers. Previous studies have shown that HOTAIR is involved in the proliferation and tumorigenesis of renal carcinoma cells, while microRNA (miR)-217 functions as a tumor suppressor in renal cell carcinoma (Rcc). However, the underlying molecular mechanism of HOTAIR in Rcc, especially in association with miR-217, has not been studied. In this study, we first demonstrated that HOTAIR expression was upregulated, which was correlated with tumor progression, and miR-217 downregulated in Rcc tissues and cells. Importantly, HOTAIR expression was negatively correlated with miR-217 expression in Rcc tissues. Gain- and loss-of-function of HOTAIR revealed that HOTAIR functioned as a ceRNA for miR-217 to facilitate HIF-1α expression and then upregulated AXL level promoting Rcc proliferation, migration, and EMT process, and inhibiting apoptosis. Furthermore, HOTAIR knockdown suppressed tumor growth and reduced the expression of proliferation antigen ki-67, HIF-1α, and AXL, but upregulated the expression of miR-217 in vivo. Finally, with AXL inhibitor BGB324, we confirmed that HOTAIR promoted Rcc activity through AXL signaling both in vitro and in vivo. In conclusion, these results suggest that HOTAIR promotes Rcc tumorigenesis via miR-217/HIF-1α/AXL signaling, which may provide a new target for the diagnosis and therapy of Rcc disease.