RETRACTED: ANRIL acts as onco-lncRNA by regulation of microRNA-24/c-Myc, MEK/ERK and Wnt/β-catenin pathway in retinoblastoma

Sevoflurane Represses Proliferation and Migration of Glioma Cells by Regulating the ANRIL/let-7b-5p Axis

Background: Glioma is a malignant brain tumor with poor prognosis. Sevoflurane has been shown to have antitumor effects in various cancers. However, the underlying role and mechanism of sevoflurane in glioma is still unclear. Materials and Methods: Glioma cell lines were exposed different concentrations of sevoflurane (sev). The cell proliferation and migration were examined by Cell Counting Kit-8 (CCK-8) and Transwell assays, respectively. All protein levels were measured by Western blot. The levels of noncoding RNA in the INK4 locus (ANRIL) and let-7b-5p were detected by quantitative real-time polymerase chain reaction. The binding sites between ANRIL and let-7b-5p were predicted by StarBase v.3.0 and confirmed using dual-luciferase reporter assay. Results: Sevoflurane treatment suppressed proliferation and migration of glioma cells. The expression of ANRIL was downregulated in glioma cells after treatment with sevoflurane in a dose-dependent manner, and overexpression of ANRIL reversed sevoflurane-induced inhibition of proliferation and migration of glioma cells. Furthermore, let-7b-5p was targeted by ANRIL, and ANRIL knockdown recovered the promoting effects of silencing let-7b-5p on proliferation, migration, and JAK2/STAT3 pathway in sevoflurane-treated glioma cells. Conclusions: Sevoflurane hindered proliferation and migration through JAK2/STAT3 pathway mediated by ANRIL and let-7b-5p in glioma cells, indicating a new reference for the application of anesthetics like sevoflurane in glioma.

From diagnosis to therapy: The transformative role of lncRNAs in eye cancer management

The genomic era has brought about a transformative shift in our comprehension of cancer, unveiling the intricate molecular landscape underlying disease development. Eye cancers (ECs), encompassing diverse malignancies affecting ocular tissues, pose distinctive challenges in diagnosis and management. Long non-coding RNAs (lncRNAs), an emerging category of non-coding RNAs, are pivotal actors in the genomic intricacies of eye cancers. LncRNAs have garnered recognition for their multifaceted roles in gene expression regulation and influence on many cellular processes. Many studies support that the lncRNAs have a role in developing various cancers. Recent investigations have pinpointed specific lncRNAs associated with ECs, including retinoblastoma and uveal melanoma. These lncRNAs exert control over critical pathways governing tumor initiation, progression, and metastasis, endowing them with the ability to function as evaluation, predictive, and therapeutic indicators. The article aims to synthesize the existing information concerning the functions of lncRNAs in ECs, elucidating their regulatory mechanisms and clinical significance. By delving into the lncRNAs' expanding relevance in the modulation of oncogenic and tumor-suppressive networks, we gain a deeper understanding of the molecular complexities intrinsic to these diseases. In our exploration of the genomic intricacies of ECs, lncRNAs introduce a fresh perspective, providing an opportunity to function as clinical and therapeutic indicators, and they also have therapeutic benefits that show promise for advancing the treatment of ECs. This comprehensive review bridges the intricate relationship between lncRNAs and ECs within the context of the genomic era.

High expression of ANRIL correlated with the poor prognosis in patients with cancer: A meta-analysis

BACKGROUND

ANRIL, also called CDKN2B antisense RNA 1, is an important genetic susceptibility locus for cardiovascular diseases and associated with numerous pathologies, including several human cancers.

OBJECTIVE

The relationship between ANRIL and the clinical outcome or prognosis of cancer patients was analyzed in this meta-analysis.

METHODS

One thousand seven hundred eight cancer patients were selected in 23 studies from 3 databases (Pubmed, Cochrane Library, and EMBASE).

RESULTS

A fixed-effects model indicated that the high expression of ANRIL is obviously linked to poor overall survival (OS) (Hazard ratio [HR] = 1.77, 95% confidence interval [CI] = 1.57-2.00, P < .00001); the random-effects model revealed poor disease-free survival (DFS) (HR = 1.86, 95% CI: 1.46-2.37, P < .00001). A high level of ANRIL expression was also associated with the tumor size (small vs large, odds ratio [OR] = 0.57, 95% CI: 0.39-0.83, P = .003), TNM stage (I + II vs III + IV; OR = 0.40, 95% CI: 0.24-0.69, P = .0008), and lymph node metastasis (LNM) (Yes vs No, OR = 3.66, 95% CI: 1.46-9.17, P = .006). ANRIL was not related significantly to histologic differentiation compared to poor with moderate + well; the OR value is 0.74, 95% CI: 0.26-2.12, P = .58. In addition, evidence suggested that a high level of ANRIL was positively associated with human cancer type, follow-up time, and sample size.

CONCLUSION

This meta-analysis demonstrated that ANRIL may be a valuable biomarker for predicting poor prognosis in cancer patients.

Knockdown of NRMT enhances sensitivity of retinoblastoma cells to cisplatin through upregulation of the CENPA/Myc/Bcl2 axis

Chemotherapy resistance of tumor cells causes failure in anti-tumor therapies. Recently, N-terminal regulator of chromatin condensation 1 methyltransferase (NRMT) is abnormally expressed in different cancers. Hence, we speculate that NRMT may pay a crucial role in the development of chemosensitivity in retinoblastoma. We characterized the upregulation of NRMT in the developed cisplatin (CDDP)-resistant retinoblastoma cell line relative to parental cells. Loss-of-function experiments demonstrated that NRMT silencing enhanced chemosensitivity of retinoblastoma cells to CDDP. Next, NRMT was identified to enrich histone-H3 lysine 4 trimethylation in the promoter of centromere protein A (CENPA) by chromatin immunoprecipitation assay. Rescue experiments suggested that CENPA reduced chemosensitivity by increasing the viability and proliferation and reducing apoptosis of CDDP-resistant retinoblastoma cells, which was reversed by NRMT. Subsequently, CENPA was witnessed to induce the transcription of Myc and to elevate the expression of B cell lymphoma-2. At last, in vivo experiments confirmed the promotive effect of NRMT knockdown on chemosensitivity of retinoblastoma cells to CDDP in tumor-bearing mice. Taken together, NRMT is an inhibitor of chemosensitivity in retinoblastoma. Those findings shed new light on NRMT-targeted therapies for retinoblastoma.

CDKN2B antisense RNA 1 suppresses tumor growth in human colorectal cancer by targeting MAPK inactivator dual-specificity phosphatase 1

Aberrant expression of long noncoding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) has been detected in human colorectal cancer (CRC). This study aimed to investigate the role of CDKN2B-AS1 and the underlying mechanism in human CRC. Gain- and loss-of-function assays were performed to explore the role of CDKN2B-AS1 in the malignant behavior of HCT116 and SW480 CRC cells in vitro and in vivo. RNA pull-down assay was conducted to identify the target of CDKN2B-AS1 in CRC cells. The physical and functional interactions between CDKN2B-AS1 and the target were examined. CDKN2B-AS1 inhibited CRC cell proliferation and migration while promoting apoptosis in vitro via activation of mitogen-activated protein kinase kinases (MEK)/extracellular signal-regulated kinase (ERK)/p38 signaling. CDKN2B-AS1 bound to mitogen-activated protein kinase (MAPK) inactivator dual-specificity phosphatase 1 (DUSP1) in CRC cells. In contrast to CDKN2B-AS1, DUSP1 promoted CRC cell proliferation, suppressed apoptosis and inactivated MEK/ERK/p38 signaling in CRC cells. Furthermore, CDKN2B-AS1 overexpression attenuated DUSP1 expression in normal colonic myofibroblasts and CRC cells. Overexpression of DUSP1 effectively countered the activation of MEK/ERK/p38 signaling induced by CDKN2B-AS1 overexpression or further blocked MEK/ERK/p38 signaling suppressed by CDKN2B-AS1 silencing. In the mouse xenograft model, CDKN2B-AS1 suppressed CRC growth, whereas DUSP1 promoted CRC growth. CDKN2B-AS1 induced cell apoptosis while suppressing EMT (epithelial-mesenchymal transition), whereas DUSP1 suppressed cell apoptosis while inducing EMT in CRC, as evidenced by the alterations in the protein levels of apoptosis and EMT markers in tumor tissue samples. CDKN2B-AS1 regulates CRC cell growth and survival by targeting MAPK inactivator DUSP1.

MiR-142-5p serves as a tumor suppressor in retinoblastoma cells by regulating MYCN

Retinoblastoma is an intraocular malignant tumor and generally occurred in childhood. Here, we intended to appraise the functional influence of microRNA-142-5p (miR-142-5p) in retinoblastoma. MiR-142-5p was declined, and MYCN was upregulated in retinoblastoma tissues and cells. Moreover, miR-142-5p restricted cell proliferation, migration, invasion, and enhanced cell apoptosis in retinoblastoma cells. MYCN was adversely controlled by miR-142-5p. Besides, the inhibition of miR-142-5p-mediated effects on retinoblastoma progression were blocked by MYCN overexpression in retinoblastoma cells. This research illustrated that miR-142-5p restricted retinoblastoma progression via interacting with MYCN.

The role of lncRNA ANRIL in the progression of hepatocellular carcinoma

OBJECTIVES

The aim of the current study was to identify the long noncoding RNAs (lncRNAs) ANRIL function and molecular pathways underlying hepatocellular carcinoma progression.

METHODS

ANRIL knockdown with specific siRNA, and transfected into HepG2 cells according to the protocol of Lipofectamine 2000. Cell proliferation, apoptosis, migration and metastasis were assessed with MTT assay, flow cytometry and wound healing assay, respectively. Moreover, the expression level of ANRIL, apoptosis-related genes, and the Wnt pathway-associated genes were assessed by real time-PCR and Western blot assay.

KEY FINDINGS

Knocking down of ANRIL led to alleviated cell growth and increased cell apoptosis of HepG2 cells through markedly increased expression levels of Bax and Bad. In contrast, dramatically diminished the expressions of anti-apoptotic factors including Bid and Bcl-2 in comparison to the scrambled control group (si-NC). Furthermore, ANRIL silencing resulted in an inactivated Wnt/β-catenin pathway by suppressing key genes associated with this pathway.

CONCLUSIONS

Taken together, these findings imply new insights into the regulatory network of the Wnt pathway through lncRNA ANRIL that indicate ANRIL may be a therapeutic factor potential for hepatocellular carcinoma.

Long Noncoding RNA TRPM2-AS Promotes the Growth, Migration, and Invasion of Retinoblastoma via miR-497/WEE1 Axis

Long noncoding RNAs (lncRNAs) exhibit vital roles in many types of cancer, including retinoblastoma (RB), the most common primary intraocular malignancy tumor of infancy. A novel lncRNA TRPM2-AS has been demonstrated to be related to multiple cancers; however, its role in RB remains unclear. Here, we aimed to investigate the function of TRPM2-AS in RB. In this study, TRPM2-AS expression in 35 human RB tissues and RB cell lines was detected by real-time PCR. And, the relationship between its expression and clinicopathological characteristics of RB patients was analyzed. RB cells’ proliferation, migration, invasion, apoptosis, and cell cycle were explored after silencing TRPM2-AS. The mechanism of TRPM2-AS in RB was focused on miR-497/WEE1 axis. Additionally, the role and mechanism of TRPM2-AS were confirmed in a xenograft mouse model. We found TRPM2-AS expression was enhanced in RB tissues and cells. And, higher TRPM2-AS expression was related to advanced clinical stage and optic nerve invasion in patients. Downregulation of TRPM2-AS significantly inhibited proliferation, migration, and invasion, elevated apoptosis, attenuated G2/M phase arrest in RB cells, and suppressed tumor growth in vivo. TRPM2-AS acted as a ceRNA for miR-497 to positively regulate WEE1 expression. miR-497 inhibitor or WEE1 overexpression dramatically reversed the effects of TRPM2-AS downregulating on the malignant phenotypes of RB cells. Therefore, TRPM2-AS is an oncogenic lncRNA in RB, and it functions largely through the miR-497/WEE1 pathway. Despite the limited sample size, this study indicates that TRPM2-AS may be a candidate target in RB therapies.

The roles of long non-coding RNAs in ocular diseases

In recent years, lncRNAs have been shown to regulate gene expression at the epigenetic, transcriptional and translational level, thus exerting various functions in biological and pathological processes involving cell proliferation, apoptosis, cell cycle and immune response. An increasing number of researches have unveiled that lncRNAs are dysregulated in pathogenesis and the development of different ocular diseases, such as glaucoma, cataract, retinal disease and ocular tumors. Also, it has been reported that lncRNAs may exert significant roles in various ocular diseases. Here, we summarized the functions of lncRNAs on relevant ocular diseases and further clarified their mechanisms. Here, several previous studies with detailed information of lncRNAs which have been proved to be the diagnostic or prognostic biomarkers and potential therapeutic targets were included. Also, it is our hope to provide a thorough knowledge of the functions of lncRNAs in eye diseases and the methods by which lncRNAs can influence ocular diseases.

Down-regulation of long non-coding RNA antisense non-coding RNA in the INK4 locus suppresses OVCAR-3 cells proliferation and induction of apoptosis by Wnt/β -catenin

OBJECTIVES

Ovarian cancer is a lethal gynecological malignancy. Long non-coding RNA antisense non-coding RNA in the INK4 locus (lncRNA ANRIL) was reported to have a critical role in cancer advancement. The ANRIL-mediated oncogenic underlying molecular mechanisms are not fully understood in ovarian cancer. We aimed to study ANRIL silencing effects on the proliferation and apoptosis of OVCAR-3 cells.

METHODS

The ANRIL was Knockdown by transfection of OVCAR-3 cells with si-RNA against ANRIL. MTT assay and cell death ELISA kit were used to evaluate cellular proliferation and apoptosis. The expression levels of ANRIL, pro-and anti-apoptotic genes were assessed using q-RT-PCR. Western blotting was used to assess Wnt/β-catenin signalling pathway.

KEY FINDINGS

ANRIL down-regulating in OVCAR-3 cell lines resulted in significant inhibition of cellular proliferation, apoptosis induction, as well as suppression of cellular invasion. Besides, knockdown of ANRIL led to pro-apoptotic genes up-regulation, Bad and Bax and anti-apoptotic genes down-regulation, Bid and Bcl-2. More importantly, we observed that ANRIL inhibition suppressed the vital components expression of the Wnt/β-catenin cascade.

CONCLUSION

Our findings showed that down-regulation of lncRNA ANRIL resulted in the effective suppression of OVCAR-3 cell proliferation and invasion and induction of apoptosis by preventing Wnt/β-catenin signal transduction.

Knockdown of lncRNA NEAT1 expression inhibits cell migration, invasion and EMT by regulating the miR-24-3p/LRG1 axis in retinoblastoma cells

Retinoblastoma (RB) is the most common primary intraocular cancer type that occurs during retinal development in childhood. Previous studies have reported that long non-coding RNAs (lncRNAs) are involved in the development of RB. Therefore, the aim of the present study was to investigate the effects and underlying regulatory mechanisms of nuclear paraspeckle assembly transcript 1 (NEAT1) in RB. The expression levels of NEAT1, microRNA (miR)-24-3p and leucine-rich-α-2-glycoprotein (LRG1) were detected using reverse transcription-quantitative PCR (RT-qPCR). Moreover, the protein expression levels of LRG1, matrix metalloproteinase 9, N-cadherin and E-cadherin were detected via western blotting. Furthermore, cell migration and invasion abilities were evaluated via Transwell assays. The targeting relationships between miR-24-3p and NEAT1 or LRG1 were predicted using online software and confirmed via dual-luciferase reporter assay. In the present study, NEAT1 and LRG1 were upregulated, and miR-24-3p was downregulated in RB tissues and cells compared with the corresponding healthy tissues and cells. Moreover, miR-24-3p was identified as a target of NEAT and LRG1 was demonstrated to be a direct target gene of miR-24-3p. Knockdown of NEAT1 or LRG1 significantly suppressed RB cell migration and invasion ability, while the effects were reversed by an miR-24-3p inhibitor. In addition, the downregulation of LRG1 caused by miR-24-3p was restored following the overexpression of NEAT1 in RB cells. It was also demonstrated that NEAT1 knockdown inhibited the epithelial-to-mesenchymal transition (EMT) pathway by inhibiting the expression of LRG via targeting miR-24-3p. In conclusion, the present results suggest that silencing of NEAT1 suppresses cell migration, invasion and the EMT process by downregulating LRG1 expression via sponging miR-24-3p in RB, thus indicating that NEAT1 may be a potential candidate for RB treatment.

microRNA-362-3p targets USP22 to retard retinoblastoma growth via reducing deubiquitination of LSD1

Accumulating evidence has reported the role of microRNA (miR) in retinoblastoma (RB). Therefore, the objective was to discuss how miR-362-3p exerted its function in RB cell progression via regulating ubiquitin-specific protease 2 (USP22) and lysine-specific histone demethylase 1 (LSD1). MiR-362-3p, USP22 and LSD1 expression in RB cells and tissues were tested. The biological functions of RB cells were detected via over-expressing miR-362-3p and down-regulating USP22. The target relationship of USP22 and miR-362-3p as well as the interaction of USP22 and LSD1 in RB was verified. Down-regulated miR-362-3p and up-regulated USP22 and LSD1 were demonstrated in RB tissues and cells. Restoring miR-362-3p and depleting USP22 attenuated invasion, proliferation and migration, and facilitated apoptosis of RB cells. USP22 was a target gene of miR-362-3p. USP22 deubiquitinated LSD1 in RB. It is revealed that miR-362-3p targets USP22 and then restrains invasion, proliferation and migration while promotes apoptosis of RB via reducing LSD1 modified by deubiquitination.

Long Noncoding RNA ZFPM2-AS1 Knockdown Restrains the Development of Retinoblastoma by Modulating the MicroRNA-515/HOXA1/Wnt/β-Catenin Axis

Purpose

The tumor-initiating function of long non-coding RNA (lncRNA), zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) was reported in lung cancer, yet the relevance of ZFPM2-AS1 in retinoblastoma (RB), a malignancy representing 2.5% to 4% incidence of cancers among children, has not been elucidated. Thus, we attempted to assess the effect of ZFPM2-AS1 and underlying mechanism in RB progression.

Methods

First, comparing the differentially expressed lncRNAs in normal retinal tissues as well as RB tissues, the target lncRNA ZFPM2-AS1 was screened out. We then assayed the ZFPM2-AS1 expression in three RB cell lines, and carried out methylthiazol tetrazolium (MTT), transwell assays, and flow cytometric analyses to examine the role of si-ZFPM2-AS1 on cell behaviors. Following online database predication, the correlations between ZFPM2-AS1 and microR-515 (miR-515) or homeobox A1 (HOXA1) were corroborated by dual-luciferase reporter gene assays. Quantitative real-time PCR along with Western blot assays was fulfilled to ascertain the expression of relevant genes.

Results

ZFPM2-AS1 was significantly overexpressed in RB tissues and cell lines, and ZFPM2-AS1 silencing curtailed the growth and metastasis of RB cells both in vitro and in vivo. Bioinformatic websites and dual-luciferase reporter gene assays disclosed that ZFPM2-AS1 might perform as a competing endogenous RNA for miR-515 and positively correlate with HOXA1 to activate the Wnt/β-catenin signaling pathway.

Conclusions

Altogether, these data demonstrated that ZFPM2-AS1 interacted with HOXA1 to promote RB development via mediating miR-515, establishing a promising therapeutic biomarker for RB and prognosis.

MicroRNA-24 in Cancer: A Double Side Medal With Opposite Properties

MicroRNA-24 (miR-24) has been widely studied in a variety of human cancers, which plays different roles in specific type of cancers. In the present review, we summarized the recent surveys regarding the role of miR-24 in different human cancers. On the one hand, miR-24 was reported to be down-regulated in some types of cancer, indicating its role as a tumor suppressor. On the other hand, it has shown that miR-24 was up-regulated in some other types of cancer, even in the same type of cancer, suggesting the role of miR-24 being as an oncogene. Firstly, miR-24 was dysregualted in human cancers, which is related to the clinical performance of cancer patients. Thus miR-24 could be used as a potential non-invasive diagnostic marker in human cancers. Secondly, miR-24 was associated with the tumor initiation and progression, being as a promoter or inhibitor. Therefore, miR-24 might be an effective prognostic biomarker in different type of cancers. Lastly, the abnormal expression of miR-24 was involved in the chemo- and radio- therapies of cancer patients, indicating the role of miR-24 being as a predictive biomarker to cancer treatment. Totally, miR-24 contributes to tumorigenesis, tumor progression, and tumor therapy, which closely related to clinic. The present review shows that miR-24 plays a double role in human cancers and provides plenty of evidences to apply miR-24 as a potential novel therapeutic target in treating human cancers.

Long non-coding RNA TRPM2-AS sponges microRNA-138-5p to activate epidermal growth factor receptor and PI3K/AKT signaling in non-small cell lung cancer

Background

Long non-coding RNAs (lncRNAs) can play pivotal roles in tumor progression by acting as microRNA (miRNA) sponges. This study aimed to investigate the association of a novel lncRNA, TRPM2-AS, with the miR-138-5p/EGFR axis in the development of non-small cell lung cancer (NSCLC).

Methods

Sixty NSCLC tissues and paired adjacent non-tumor tissues were analyzed. The relative expression levels of TRPM2-AS, miR138-5p, and epidermal growth factor receptor (EGFR) and the interactions between them were analyzed. The NSCLC cell lines NCI-H1299 and A549 were transfected with TRPM2-AS shRNA/pcDNA, and miR-138-5p mimics. Cell proliferation, migration, invasion, and apoptosis were examined in response to different transfection conditions. Dual-luciferase reporter assay was performed to identify the target interactions between TRPM2-AS, miR-138-5p, and EGFR. A549 cells stably transfected with shRNA were injected into BALB/c null nude mice to establish a tumor xenograft model.

Results

TRPM2-AS was up-regulated in NSCLC tumors and cell lines. Cell proliferation, migration, and invasion were inhibited in NSCLC cells treated with sh-TRPM2-AS, while apoptosis was induced. The targeting of TRPM2-AS by miR138-5p and miR138-5p by EGFR were validated with dual-luciferase reporter assay. TRPM2-AS was found to be negatively correlated with miR138-5p but positively correlated with EGFR. PI3K/AKT/mTOR was activated by pcDNA-EGFR but inactivated by miR-138-5p mimics. In the tumor xenograft mouse model, sh-TRPM2-AS suppressed tumor formation, reduced the expression of EGFR and Ki67, and promoted tumor cell apoptosis.

Conclusions

Our results suggested that TRPM2-AS can increase the levels of EGFR via sponging miR-138-3p; this promoted NSCLC cell proliferation, migration, and invasion in vitro, and exacerbated tumors in vivo. These findings highlight TRPM2-AS/miR-138-5p as a potential target for reducing drug resistance in patients with NSCLC.

Dysregulation of LncRNA ANRIL mediated by miR-411-3p inhibits the malignant proliferation and tumor stem cell like property of multiple myeloma via hypoxia-inducible factor 1α

Long non-coding RNA (lncRNA) ANRIL has been reported to be closely related to the relapse of multiple myeloma patients. However, the functional role and underlying mechanism of lncRNA ANRIL in multiple myeloma are not known. This study aims to investigate the biological function of lncRNA ANRIL in multiple myeloma. In this study, compared with normal tissues from healthy donors, lncRNA ANRIL and HIF-1α expressions were up-regulated in tumor tissues from multiple myeloma patients. miR-411-3p expression was down-regulated in tumor tissues from multiple myeloma patients. Besides, lncRNA ANRIL can interact with miR-411-3p. HIF-1α was confirmed to be a target of miR-411-3p. Correlation analysis showed that lncRNA ANRIL expression was negatively correlated with miR-411-3p expression. HIF-1α expression was negatively correlated with miR-411-3p expression. Further transfection experiments showed that knockdown of ANRIL or overexpression of miR-411-3p significantly inhibited cell proliferation, tumor formation ability and tumor stem cell like property, promoted cell apoptosis in vitro. Finally, miR-411-3p mimic reduced tumor volume, improved survival rate, suppressed malignant proliferation and tumor stem cell like property in U266 xenograft model. Our results demonstrate that lncRNA ANRIL mediated by miR-411-3p promotes the malignant proliferation and tumor stem cell like property of multiple myeloma through regulating HIF-1α.

LncRNA HOTTIP promotes the proliferation and invasion of ovarian cancer cells by activating the MEK/ERK pathway

Recent studies have revealed that long non-coding RNAs (lncRNAs) serve important roles in carcinogenesis and that this type of gene may be used as biomarkers in cancer. A high level of lncRNA HOXA distal transcript antisense RNA (HOTTIP) is associated with unfavorable prognosis for patients with ovarian cancer (OC), but the mechanism of HOTTIP involved in OC development remains to be elucidated. The present study aimed to investigate the mechanism of HOTTIP in metastasis-associated OC cell behaviors. HOTTIP levels in ovarian cells were quantified by reverse transcription-quantitative PCR, cell proliferation was analyzed by colony formation assay, and apoptosis was assessed by flow cytometry. Cell migratory and invasive abilities were evaluated by wound healing and Transwell assays, respectively. The expression levels of mitogen-activated protein kinase kinase (MEK)/ERK pathway-associated proteins were detected by western blotting. The results demonstrated that knockdown of HOTTIP in OC cells significantly reduced the phosphorylation levels of MEK and ERK, inhibited the proliferation and invasion of OC cells and promoted their apoptosis. Furthermore, the effects of HOTTIP on cell migration and invasion were partly associated with the epithelial-mesenchymal transition (EMT) process. Proliferation, invasion and EMT of OC cells were enhanced following overexpression of HOTTIP; however, these effects were reversed by the MEK/ERK pathway inhibitor U0126. In conclusion, HOTTIP was demonstrated to promote the proliferation, migration and invasion of OC cells by activating the MEK/ERK pathway. Therefore, HOTTIP may serve as a potential therapeutic target for OC.

Knock-Down of Long Non-Coding RNA ANRIL Suppresses Mouse Mesangial Cell Proliferation, Fibrosis, Inflammation via Regulating Wnt/β-Catenin and MEK/ERK Pathways in Diabetic Nephropathy

Aims Our study aimed to investigate the role of long non-coding RNA ANRIL (lnc-ANRIL) knock-down in regulating cell activities, inflammation and downstream signaling pathways in mouse mesangial cellular diabetic nephropathy (DN) model.

Methods The mouse mesangial cells (SV40-MES13 cells) were treated with high-glucose (HG) to construct cellular DN model. Lnc-ANRIL knock-down plasmid and control knock-down plasmid were transfected into HG-treated SV40-MES13 cells as Sh-ANRIL group and Sh-NC group respectively.

Results Lnc-ANRIL expression was significantly higher in HG-treated SV40-MES13 cells compared with normal glucose-treated SV40-MES13 cells and osmotic control-treated SV40-MES13 cells. Lnc-ANRIL knock-down suppressed cell proliferation and promoted cell apoptosis in HG-treated SV40-MES13 cells. As for fibrosis, lnc-ANRIL knock-down reduced fibronectin and collagen I expressions in HG-treated SV40-MES13 cells. Besides, the expressions of supernatant tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-1β, IL-6, IL-8 and IL-18 were reduced in Sh-ANRIL group compared with Sh-NC group. Furthermore, Wnt3, β-catenin, p-MEK1 and p-ERK1 expressions were suppressed in Sh-ANRIL group compared with Sh-NC group, which suggested that lnc-ANRIL knock-down inhibited Wnt/β-catenin and MEK/ERK pathways in HG-treated SV40-MES13 cells.

Conclusions Lnc-ANRIL knock-down suppresses mouse mesangial cell proliferation, fibrosis, inflammation, Wnt/β-catenin and MEK/ERK pathways in DN.

miR-3609 Decelerates the Clearance of Sorafenib in Hepatocellular Carcinoma Cells by Targeting EPAS-1 and Reducing the Activation of the Pregnane X Receptor Pathway

Background

The pregnane X receptor (PXR) not only plays an important role in cellular metabolism processes but also induces the resistance of hepatocellular carcinoma (HCC) cells to molecularly targeted drugs by mediating their metabolism and clearance by these cells. Endothelial PAS domain-containing protein 1 (EPAS-1) acts as a coactivator to regulate the transcription factor activity of PXR. In the present study, a microRNA that potentially targets EPAS-1, namely miR-3609, was identified using the miRDB tool.

Methods

The expression of miR-3609 and EPAS-1 was examined by qPCR. Lentiviral particles containing the full-length sequences of miR-3609 (pri-miR-3609) were prepared. The antitumor effect of antitumor agents was examined by the in vitro and in vivo assays.

Results

The expression of miR-3609 was negatively correlated with that of EPAS-1 in both HCC clinical specimens and paired non-tumor specimens, and the effect of miR-3609 on the expression of EPAS-1 was confirmed by Western blot experiments. Overexpression of miR-3609 decreased the expression of EPAS-1 and, in turn, repressed the activation of the PXR pathway. miR-3609 decreased the transcription factor activation of PXR, repressed its recruitment to its target gene promoter regions, and decreased the expression of its target genes CYP3A4 and P-GP. In addition, miR-3609 decelerated the metabolism and clearance of sorafenib in HCC cells and enhanced the antitumor effect of sorafenib in HCC cells.

Conclusion

Therefore, the results indicate that miR-3609 decreases the expression of EPAS-1 and enhances the sensitivity of HCC cells to sorafenib.

miR-494 promotes progression of retinoblastoma via PTEN through PI3K/AKT signaling pathway

Increasing evidence has indicated that the dysregulation of microRNA (miRNA) occur in the pathogenesis of retinoblastoma (RB). Aim of the present study was to investigate the possible role of miR-494 (miR-494-3p) in RB. It was demonstrated that miR-494 expression was increased in RB tissue samples and cell lines. Also, it was prominently associated with clinicopathological features. Functional assays showed that RB cell proliferation, invasion and migration can be promoted by miR-494 overexpression. Besides, phosphatase and tensin homolog (PTEN) was verified as a possible target of miR-494 by a luciferase assay, western blot and qRT-PCR assay in RB. miR-494 and PTEN expression was negatively related in a correlation analysis on tumor tissues of 66 patients. In addition, PTEN was proved to reverse miR-494 effect on RB cell progression. Moreover, PI3K/AKT signaling pathway was validated to take part in RB progression. Taken together, the current study proposes that miR-494 might function as a tumor promoter and regulates RB progression through targeting PTEN.

Long non-coding RNA ANRIL enhances mitochondrial function of hepatocellular carcinoma by regulating the MiR-199a-5p/ARL2 axis

Although the roles of long non-coding RNA (lncRNA) ANRIL (Antisense non-coding RNA in the INK4A locus) have been established in various tumors, its roles in mitochondrial metabolic reprogramming of hepatocellular carcinoma (HCC) cells are still unclear. This work aims to explore lncRNA ANRIL roles in regulating the mitochondrial metabolic reprogramming of liver cancer cells. First, we found that lncRAN ANRIL expression was significantly increased in HCC tissues or cells compared with the normal adjacent tissues and normal tissues or cells. Functional experiment showed that overexpression of lncRNA ANRIL promoted mitochondrial function in HCC cells, evident by the increased mitochondrial DNA copy numbers, ATP (Adenosine triphosphate) level, mitochondrial membrane potential, and the expression levels of mitochondrial markers, while ANRIL knockdown exerted the opposite effects. Mechanistically, lncRNA ANRIL acted as a competing endogenous RNA to increase ARL2 (ADP-ribosylationfactor-like 2) expression via sponging miR-199a-5p. Notably, the miR-199a-5p/ARL2 axis is necessary for ANRIL-mediated promoting effects on HCC cell mitochondrial function. This work reveals a novel ANRIL-miR-199a-5p-ARL2 axis in HCC cell progression, which might provide potential targets for HCC treatment.

Propofol upregulates miR-320a and reduces HMGB1 by downregulating ANRIL to inhibit PTC cell malignant behaviors

BACKGROUND

Our previous study states that propofol suppresses proliferation and migration of papillary thyroid cancer (PTC) cells by downregulation of lncRNA ANRIL. This study intended to probe the downstream mechanism of ANRIL in PTC with potential microRNAs (miR) and genes.

METHODS

ANRIL expression was detected in normal thyroid epithelial cells (Nthy-ori 3-1) and PTC cells (TPC-1, FTC-133, K1 and BCPAP). ANRIL expression was inhibited in TPC-1 and BCPAP cells to explore the effects of si-ANRIL in PTC malignant behaviors. The gain-and loss-of functions of ANRIL/miR-320a were performed to measure their roles in PTC. Levels of ANRIL, miR-320a, HMGB1, apoptosis- and Wnt/β-catenin and NF-κB pathways-related proteins were measured. Dual-luciferase reporter gene assay and RNA pull-down assay were applied to verify ANRIL/miR-320a/HMGB1 relation. si-ANRIL was transplanted into xenograft tumors in nude mice.

RESULTS

ANRIL was upregulated in TPC-1 and BCPAP cells. miR-320a targeted HMGB1, and ANRIL bound to miR-320a. In TPC-1 and BCPAP cells, si-ANRIL prevented PTC cell malignant behaviors, and inactivated the Wnt/β-catenin and NF-κB pathways; while si-ANRIL + miR-320a inhibition showed opposite trends. Overexpressing miR-320a promoted malignant behaviors of TPC-1 cells. In 6 μg/mL propofol-treated TPC-1 cells, miR-320a inhibition weakened propofol's inhibitory effects on PTC cell growth. After ANRIL inhibition, the volume and weight of xenograft tumors were decreased.

CONCLUSION

Propofol upregulated miR-320a and reduced HMGB1 by downregulating ANRIL and inactivating the Wnt/β-catenin and NF-κB pathways, thus preventing PTC cell malignant behaviors. This study may offer new insights in PTC prevention and treatment.

Long Non-Coding RNA CDKN2B-AS1 Facilitates Laryngeal Squamous Cell Cancer Through Regulating miR-497/CDK6 Pathway

BACKGROUND

CDKN2B antisense RNA 1 (CDKN2B-AS1), a long noncoding RNA, was reported to play crucial roles in the progression of multiple cancers. However, the functional roles and regulatory mechanism of CDKN2B-AS1 in human laryngeal squamous cell cancer (LSCC) remain unclear. The goals of this study were to investigate biological roles and underlying mechanisms of CDKN2B-AS1 in LSCC.

METHODS

The expressions of CDKN2B-AS1, miR-497 and cyclin-dependent kinase 6 (CDK6) were detected in LSCC tissues and cell lines by real-time quantitative PCR (qRT-PCR). The effects of CDKN2B-AS1 on LSCC cell proliferation, apoptosis, migration and invasion were examined by corresponding experiments. Bioinformatics analysis and luciferase activity assay were applied to analyze the interaction between CDKN2B-AS1 and miR-497.

RESULTS

The expression of CDKN2B-AS1 was significantly higher in LSCC tissues than in adjacent normal tissues. Higher CDKN2B-AS1 was closely associated with lymph node metastasis and advanced clinical stage. Moreover, CDKN2B-AS1 knockdown by siRNA significantly inhibited the proliferation, induced cell apoptosis, and suppressed migration and invasion in LSCC cells. Mechanically, CDKN2B functions as an oncogenic lncRNA in LSCC via regulating miR-497/CDK6 axis.

CONCLUSION

The observations in this study identify CDKN2B-AS1 an oncogenic role in the tumorigenesis of LSCC by regulating miR-497/CDK6 axis and indicate that it may serve as a potential target for LSCC treatment.

Bta-miR-24-3p Controls the Myogenic Differentiation and Proliferation of Fetal, Bovine, Skeletal Muscle-Derived Progenitor Cells by Targeting ACVR1B

Simple Summary

MicroRNAs play pivotal roles in skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is largely unknown. Here, we report a mechanistic study of bta-miR-24-3p, a key miRNA regulator of the myogenic differentiation of fetal bovine platelet-derived growth factor receptor alpha negative (PDGFRα^-) progenitor cells. We isolated progenitor cells from the bovine fetal longissimus dorsi muscle and purified them with PDGFRα antibodies to remove fibro-adipogenic progenitors. We observed elevated bta-miR-24-3p expression during differentiation, and bta-miR-24-3p overexpression led to promoted myogenic differentiation but suppressed proliferation. Moreover, activin receptor type 1B (ACVR1B) was identified as a direct target of bta-miR-24-3p, and ACVR1B-silencing cells exhibited similar phenotypes to bta-miR-24-3p-overexpressing bovine PDGFRα^- progenitor cells. These results extended our understanding on the roles of miRNA in fetal muscle development. The method of removing fibro-adipogenic progenitors in our study will also provide useful information for other investigators.

Abstract

MicroRNAs modulate a variety of cellular events, including skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is poorly understood. In this study, we report that bta-miR-24-3p promotes the myogenic differentiation of fetal bovine PDGFRα^- progenitor cells. The expression of bta-miR-24-3p increased during myogenic differentiation. Overexpression of bta-miR-24-3p significantly promoted myogenic differentiation, but inhibited proliferation. A dual-luciferase assay identified ACVR1B as a direct target of bta-miR-24-3p. Similarly, knocking down ACVR1B by RNA interference also significantly inhibited proliferation and promoted the differentiation of bovine PDGFRα^- progenitor cells. Thus, our study provides a mechanism in which bta-miR-24-3p regulates myogenesis by inhibiting ACVR1B expression.

MicroRNA-6077 enhances the sensitivity of patients-derived lung adenocarcinoma cells to anlotinib by repressing the activation of glucose transporter 1 pathway

Anlotinib is a novel molecular targeted agent targeting the vascular endothelial growth factor receptor, which differs from the other currently available non-small cell lung cancer (NSCLC) molecular targeted drugs targeting this receptor. Although the application of anlotinib may bring new hope for patients with advanced NSCLC, the cost of treatment is high. The results of this study showed that microRNA-6077 (miR-6077) represses the expression of GLUT1 (glucose transporter 1) and enhances the sensitivity of patient-derived lung adenocarcinoma (AC) cells to anlotinib. The miR-6077, which potentially binds to the 3'untranslated region of GLUT1, was identified and screened by miRDB, an online tool; sequences of miR-6077 were prepared as lentivirus particles. A549 cells (a lung adenocarcinoma cell line) and five patient-derived AC cell lines were infected with control miRNA or miR-6077, and subsequently treated with the indicated concentration of anlotinib. The expression of proteins, such as GLUT1, was determined by western blotting. The antitumor effect of anlotinib was identified through in-vitro (e.g., MTT) or in-vivo methods (e.g., subcutaneous tumor model). Overexpression of miR-6077 repressed the expression of GLUT1 and decreased the glucose uptake, lactate production, or ATP generation in AC cells. In addition, MiR-6077 may enhance the antitumor effect of anlotinib on A549 or patient-derived AC cell lines. Therefore, our results indicated that miR-6077 represses the expression of GLUT1 and enhances the sensitivity of patients-derived lung AC cells to anlotinib.

Long non-coding RNAs in retinoblastoma

Retinoblastoma represents 3% of all childhood cancers and is the most common intraocular malignant tumor with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have reported new insights into the mechanism of retinoblastoma development, the involvement of regulatory non-coding RNAs remains unclear. Long non-coding RNAs (lncRNAs) are a group of endogenous non-protein-coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidence has shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration, and invasion. Several lncRNAs, including BANCR, AFAP1-AS1, NEAT1, XIST, ANRIL, PlncRNA-1, HOTAIR, PANDAR, DANCR, and THOR, promote the progression and metastasis of retinoblastoma. However, some lncRNAs, such as MEG3, MT1JP, and H19, play a tumor suppressive role. Our review summarizes the functional role of lncRNAs in retinoblastoma and their potential clinical applications for diagnosis, prognosis, and treatment.

Retracted Article: Long noncoding RNA ANRIL knockdown increases sensitivity of non-small cell lung cancer to cisplatin by regulating the miR-656-3p/SOX4 axis

Long noncoding RNAs (lncRNAs) are implicated in the development of chemoresistance in many cancers. However, the effect and mechanism of lncRNA antisense noncoding RNA in the INK4 locus (ANRIL) on cisplatin (CDDP) resistance in non-small cell lung cancer (NSCLC) remain unclear. The levels of ANRIL, microRNA (miR)-656-3p and sex-determining region Y-related high-mobility group box 4 (SOX4) in NSCLC tissues and cells were detected by quantitative real-time polymerase chain reaction or western blotting. Cell viability, apoptosis, migration and epithelial-to-mesenchymal transition (EMT) were assessed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT assay), flow cytometry, trans-well assays and western blotting, respectively. The xenograft model was established using CDDP-resistant NSCLC cells. The target association between miR-656-3p and ANRIL or SOX4 was validated by luciferase reporter assay and RNA immunoprecipitation. ANRIL expression was increased in CDDP-resistant NSCLC tissues and cells. Knockdown of ANRIL decreased cell viability, migration and EMT but induced apoptosis in CDDP-resistant NSCLC cells. Moreover, silencing of ANRIL reduced xenograft tumor growth in vivo. miR-656-3p was targeted by ANRIL and its exhaustion attenuated the suppressive role of ANRIL knockdown in CDDP resistance in NSCLC cells. SOX4 acted as a target of miR-656-3p and was positively regulated by ANRIL. Collectively, interference of ANRIL repressed CDDP resistance through promoting apoptosis and inhibiting cell viability, migration and EMT by up-regulating miR-656-3p and down-regulating SOX4, indicating a new target to improve the chemotherapeutic efficacy in NSCLC.

Long noncoding RNAs (lncRNAs) are implicated in the development of chemoresistance in many cancers.