Long non-coding RNA DSCAM-AS1 upregulates USP47 expression through sponging miR-101-3p to accelerate osteosarcoma progression

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Cellular functions and molecular mechanisms of ubiquitination in osteosarcoma

Although some advances have been made in the treatment of osteosarcoma in recent years, surgical resection remains the mainstream treatment. Initial and early diagnosis of osteosarcoma could be very difficult to achieve due to the insufficient sensitivity for the means of examination. The distal metastasis of osteosarcoma also predicts the poor prognosis of osteosarcoma. In order to solve this series of problems, people begin to discover a new method of diagnosing and treating osteosarcoma. Ubiquitination, as an emerging posttranslational modification, has been shown to be closely related to osteosarcoma in studies over the past decades. In general, this review describes the cellular functions and molecular mechanisms of ubiquitination during the development of osteosarcoma.

LncRNA ZNF883-Mediated NLRP3 Inflammasome Activation and Epilepsy Development Involve USP47 Upregulation

The goal of this study was to characterize the mechanisms of long noncoding RNA (lncRNA) ZNF883 regulating NOD-like receptor 3 (NLRP3) inflammasome activation in epilepsy (EP). Rat and cellular EP models were established using pilocarpine and magnesium-free extracellular fluid, respectively, to detect the differential expression of ZNF883, microRNA (miR)-138-5p, ubiquitin-specific peptidase 47 (USP47), and NLRP3. The pathology of the hippocampal neurons was examined by whole-cell patch clamping. The expression of ZNF883, miR-138-5p, and USP47 was modified in epileptic neurons, and the EP rats were injected with sh-ZNF883. Then, alterations in ZNF883, miR-138-5p, and USP47 levels were measured. The histopathology of the hippocampus was detected, along with the detection of IL-6, IL-1β, TNF-α, and NLRP3. Neuronal apoptosis in the rat and cellular EP models was determined. The relationship among ZNF883, miR-138-5p, and USP47 as well as the regulation of NLRP3 ubiquitination by USP47 was determined. ZNF883, USP47, and NLRP3 were increasingly expressed and miR-138-5p was downregulated in epileptic neurons and rats, concurrent with aggravated inflammation and apoptosis. ZNF883 overexpression in epileptic neurons elevated USP47 expression. ZNF883 targeted miR-138-5p and miR-138-5p negatively regulated USP47. In epileptic neurons, inhibiting miR-138-5p or overexpressing USP47 partially reversed the ZNF883 silencing-induced inhibition on NLRP3 inflammasome activation, neuronal apoptosis, and epileptiform activity. ZNF883 silencing in EP rats decreased USP47 and NLRP3, increased miR-138-5p, and inhibited inflammation and apoptosis. USP47 reversed the ubiquitination of NLRP3. ZNF883 inhibits NLRP3 ubiquitination and promotes EP through upregulating USP47 by sponging miR-138-5p.

DSCAM-AS1 Long Non-Coding RNA Exerts Oncogenic Functions in Endometrial Adenocarcinoma via Activation of a Tumor-Promoting Transcriptome Profile

Accumulating evidence suggests that lncRNA DSCAM-AS1 acts tumor-promoting in various cancer entities. In breast cancer, DSCAM-AS1 was shown to be the lncRNA being most responsive to induction by estrogen receptor α (ERα). In this study, we examined the function of DSCAM-AS1 in endometrial adenocarcinoma using in silico and different in vitro approaches. Initial analysis of open-source data revealed DSCAM-AS1 overexpression in endometrial cancer (EC) (p < 0.01) and a significant association with shorter overall survival of EC patients (HR = 1.78, p < 0.01). In EC, DSCAM-AS1 was associated with endometrial tumor promotor gene PRL and with expression of ERα and its target genes TFF1 and PGR. Silencing of this lncRNA by RNAi in two EC cell lines was more efficient in ERα-negative HEC-1B cells and reduced their growth and the expression of proliferation activators like NOTCH1, PTK2 and EGR1. DSCAM-AS1 knockdown triggered an anti-tumoral transcriptome response as revealed by Affymetrix microarray analysis, emerging from down-regulation of tumor-promoting genes and induction of tumor-suppressive networks. Finally, several genes regulated upon DSCAM-AS1 silencing in vitro were found to be inversely correlated with this lncRNA in EC tissues. This study clearly suggests an oncogenic function of DSCAM-AS1 in endometrial adenocarcinoma via activation of a tumor-promoting transcriptome profile.

Ubiquitin specific peptidase 47 promotes proliferation of lung squamous cell carcinoma

BACKGROUND

Ubiquitin specific peptidase 47 (USP47) is a kind of deubiquitinase, which has been reported to play oncogenic roles in several malignancies including colorectal cancer and breast cancer.

OBJECTIVE

Here we aimed to investigate the clinical significance of USP47 in lung squamous cell carcinoma (LUSC).

METHODS

We retrospectively enrolled a cohort of LUSC patients who underwent surgical resection in our hospital (n = 280) and conducted immunohistochemistry staining for their tumor tissues targeting USP47. The correlations between USP47 expression and clinicopathological characteristics were evaluated by Chi-square test. Univariate and multivariate analyses were conducted to assess the prognostic predictive role of USP47 in LUSC. Cell lines and mice models were utilized to explore the tumor-related functions of USP47 in vitro and in vivo, respectively.

RESULTS

Among the 280 cases, there were 127 cases classified as high-USP47 expression and 153 cases with low-USP47 expression. Statistical analyses revealed that higher USP47 expression was independently correlated with larger tumor size, advanced T stage, and unfavorable prognosis. Knockdown of USP47 by shRNA resulted in impaired proliferation of LUSC cell lines and reduced nucleus beta-catenin level. Furthermore, xenograft assays demonstrated that silencing USP47 can inhibit LUSC tumor growth in vivo.

CONCLUSION

Our research established a novel tumor-promoting effect and prognostic predictive role of USP47 in LUSC, thereby providing evidence for further therapeutic development.

MicroRNA-101-3p Suppresses Cancer Cell Growth by Inhibiting the USP47-Induced Deubiquitination of RPL11

Simple Summary

An abnormal expression of microRNA is commonly observed in cancer. Since a single miRNA can target numerous genes, it is important to understand the exact mechanism for the regulation of cancer growth by miRNAs. Here, we show that miR-101-3p, which is downregulated in several cancers, regulates RPL11 ubiquitination by targeting USP47, thereby controlling p53 levels by affecting the localization of RPL11 and its interaction with MDM2. Our results provide a novel mechanism for the inhibition of cancer cell growth by miR-101-3p, and suggest that miR-101-3p could be a potential target as an anticancer agent.

Abstract

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that regulate a countless number of genes in the cell, and the aberrant expression of miRNA can lead to cancer. Here, we demonstrate that miR-101-3p regulates the RPL11–MDM2–p53 pathway by targeting ubiquitin-specific peptidase 47 (USP47), consequently inhibiting cancer cell proliferation. We confirm that miR-101-3p directly binds to the 3′-UTR region of the USP47 gene and inhibits USP47 expression. In addition, the overexpression of miR-101-3p suppresses cell proliferation in a p53-dependent manner. MiR-101-3p promotes interaction between RPL11 and MDM2 by inducing the translocation of RPL11 from the nucleolus to the nucleoplasm, thus preventing the MDM2-mediated proteasomal degradation of p53. However, these phenomena are restored by the overexpression of USP47, but not by its catalytically inactive form. Indeed, miR-101-3p regulates RPL11 localization and its interaction with MDM2 by inhibiting the USP47-induced deubiquitination of RPL11. Finally, the expression of miR-101-3p is downregulated in lung cancer patients, and the patients with low miR-101-3p expression exhibit a lower survival rate, indicating that miR-101-3p is associated with tumorigenesis. Together, our findings suggest that miR-101-3p functions as a tumor suppressor by targeting USP47 and could be a potential therapeutic target for cancers.

A Review on the Carcinogenic Roles of DSCAM-AS1

Long non-coding RNAs (lncRNAs) are a group of transcripts with fundamental roles in the carcinogenesis. DSCAM Antisense RNA 1 (DSCAM−AS1) is an example of this group of transcripts which has been firstly identified in an attempt to find differentially expressed transcripts between breast tumor cells and benign breast samples. The pathogenic roles of DSCAM-AS1 have been vastly assessed in breast cancer, yet its roles are not restricted to this type of cancer. Independent studies in non-small cell lung cancer, colorectal cancer, osteosarcoma, hepatocellular carcinoma, melanoma and cervical cancer have validated participation of DSCAM-AS1 in the carcinogenic processes. miR-577, miR-122-5p, miR-204-5p, miR-136, miR−137, miR−382, miR−183, miR−99, miR-3173-5p, miR-874-3p, miR-874-3p, miR-150-5p, miR-2467-3p, miR-216b, miR-384, miR-186-5p, miR-338-3p, miR-877-5p and miR-101 are among miRNAs which interact with DSCAM-AS1. Moreover, this lncRNA has interactions with Wnt/β-catenin pathway. The current study aims at summarization of the results of studies which focused on the assessment of oncogenic role of DSCAM-AS1.

Role of Ubiquitin-Specific Peptidase 47 in Cancers and Other Diseases

Deubiquitination is the reverse process of ubiquitination, which is catalyzed by deubiquitinase enzymes. More than 100 deubiquitinases have been identified. Ubiquitin-specific peptidase 47 (USP47), a member of the ubiquitin-specific protease family with high homology to USP7, is an active molecule with a wide range of functions and is closely associated with cancer and other diseases. However, no systematic summary exists regarding the functions of USP47. Here, we summarize the functions and expression regulation of USP47. USP47 is highly expressed in many tumors and is widely involved in tumor development, metastasis, drug resistance, epithelial-mesenchymal transition, and other processes. Targeted inhibition of USP47 can reverse malignant tumor behavior. USP47 also plays a role in inflammatory responses, myocardial infarction, and neuronal development. USP47 is involved in multiple levels of expression-regulating mechanisms, including transcriptional, post-transcriptional, and post-translational modifications. Development of targeted inhibitors against USP47 will provide a basis for studying the mechanisms of USP47 and developing therapeutic strategies for cancers and other diseases.

Inhibition of MicroRNA miR-101-3p on prostate cancer progression by regulating Cullin 4B (CUL4B) and PI3K/AKT/mTOR signaling pathways

To probe into the efffects of miR-101-3p via regulating CUL4B within PI3K/AKT/mTOR signaling pathway on progression of prostate cancer (PCA). Western blot and qRT-PCR were adopted to detect CUL4B and miR-101-3p expressions in 75 cases with PCA . The cellular strains of PCA (LNCaP and PC3) were chose as the objects to check the targeting correlation between CUL4B and miR-101-3p through dual-luciferase reporter experiments. LNCaP cells and PC3 cells were randomly divided into the blank group, miR-101-3p mimic group, siRNA negative control (NC) group, CUL4B siRNA group and CUL4B siRNA plus the miR-101-3p inhibitor group. Cellular bioactivity measurement was done via Cell-Light EDU, MTT, Annexin-V-FITC/PI, scratch-heal experiments and invasion tests of Transwell. MiR-101-3p expression was decreased more signally in tumor tissues than in normal tissues adjacent to the cancer. MiR-101-3p inhibited cellular proliferating, migrating and invasion. Nevertheless, it promoted cellular apoptosis, up-regulated apoptotic proteins as well as down-regulated anti-apoptotic proteins. CUL4B siRNA and miR-101-3p simulation were similar in terms of their outcomes. Nonetheless, these results could be reversed through the miR-101-3p inhibitor. Besides, CUL4B siRNA and the simulation halted a serious of PI3K signal in PCA cells. MiR-101-3p expression was down-regulated in PCA patients. CUL4B was upregulated in PCA patients. Moreover, miR-101-3p suppressed cellular invasion, migration, proliferation and led to cellular apoptosis, which might be related to the PI3K/AKT/mTOR signaling pathway suppression. Finally, we found, MiR-101-3P suppressed PCA progression via aiming for CUL4B, which may offer the new molecular target for PCA clinical treatment.

Long-non-coding RNA RUSC1-AS1 accelerates osteosarcoma development by miR-101-3p-mediated Notch1 signalling pathway

Background

Long non-coding RNA (lncRNA) RUSC1-AS1 has been found to modulate several cancers development. In this study, we explored the role of RUSC1-AS1 on osteosarcoma (OS) progression.

Methods

Quantitative Real-time PCR (qRT-PCR) was conducted to test the relative expression of RUSC1-AS1, Notch1 mRNA and miR-101-3p in OS tissues and adjacent normal tissues. Gain- or loss- of functional assays were carried out to determine the roles of RUSC1-AS1 and miR-101-3p in OS progression both in vitro and in vivo. The expression of E-cadherin, N-cadherin, Vimentin, Snail, Notch1, Ras and ERK was determined by Western blot. Furthermore, the relationships between RUSC1-AS1 and miR-101-3p, Notch1 and miR-101-3p were confirmed through RNA immunoprecipitation (RIP) and dual luciferase reporter gene assay.

Results

RUSC1-AS1 and Notch1 were up-regulated in OS cells and tissues. Down-regulating RUSC1-AS1 significantly attenuated the proliferative, epithelial-mesenchymal transition (EMT), growth, lung metastasis, migrative and invasive abilities of MG-63 and Saos-2 cells, and aggravated apoptosis, accompanied with down-regulated Notch1-Ras-ERK1/2 in those cells both in vitro and in vivo, while overexpression of RUSC1-AS1 exerted opposite effects. Overexpressing miR-101-3p in OS cells had similar effects as RUSC1-AS1 inhibition. In addition, RUSC1-AS1 functioned as a competing endogenous RNA (ceRNA) to competitively sponge miR-101-3p, thus upregulating Notch1 expression and mediating the malignant behaviors of OS cells.

Conclusion

RUSC1-AS1 is a novel oncogenic lncRNA in OS through the miR-101-3p-Notch1-Ras-ERK pathway, which might be a potential therapeutic target for OS.

Functional interplay between long non-coding RNAs and the Wnt signaling cascade in osteosarcoma

Osteosarcoma is a common and highly malignant bone tumor among children, adolescents and young adults. However, the underlying molecular mechanisms remain largely unexplored. LncRNAs are transcripts with no or limited protein-coding capacity in human genomes, and have been demonstrated to play crucial functions in initiation, progression, therapeutic resistance, recurrence and metastasis of tumor. Considerable studies revealed a dysregulated lncRNA expression pattern in osteosarcoma, which may act as oncogenes or suppressors to regulate osteosarcoma progression. Wnt signaling pathway is an important cascade in tumorigenesis by modulation of pleiotropic biological functions including cell proliferation, apoptosis, differentiation, stemness, genetic stability and chemoresistance. Hyperactivation or deficiency of key effectors in Wnt cascade is a common event in many osteosarcoma patients. Recently, increasing evidences have suggested that lncRNAs could interplay with component of Wnt pathway, and thereby contribute to osteosarcoma onset, progression and dissemination. In this review, we briefly summarize Wnt signaling-related lncRNAs in osteosarcoma progression, aiming to gain insights into their underlying crosstalk as well as clinical application in osteosarcoma therapeutic modalities.

LncRNA BCRT1 facilitates osteosarcoma progression via regulating miR-1303/FGF7 axis

Growing studies noted that lncRNA was closely related with the initiation and progression of tumors. However, the role of BCRT1 in the progression of osteosarcoma remains unknown. We noted that BCRT1 is significantly upregulated in osteosarcoma specimens and cells. Elevated expression of BCRT1 promotes cell growth and cell cycle in osteosarcoma cell. Moreover, BCRT1 induces EMT and secretion of inflammatory mediators in osteosarcoma cell. We illustrated that elevated expression of BCRT1 decreases miR-1303 expression in MG-63 cell. The expression of miR-1303 is lower in osteosarcoma specimens than in non-tumor specimens. There is an inverse interrelation between miR-1303 levels and BCRT1 levels in osteosarcoma specimens. Furthermore, we identified FGF7 is one direct target gene of miR-1303 in osteosarcoma cell. Ectopic expression of miR-1303 suppresses FGF7 expression and elevated expression of BCRT1 enhanced FGF7 expression in MG-63 cell. Finally, we illustrated that BCRT1 induces osteosarcoma cell cycle and proliferation and promotes EMT progression and inflammatory mediators secretion via modulating FGF7 expression. Our study suggested that BCRT1 acts as one oncogene in osteosarcoma progression.

Long non‑coding RNA KCNQ1OT1 promotes nasopharyngeal carcinoma cell cisplatin resistance via the miR‑454/USP47 axis

Long non‑coding RNAs serve an essential role in drug resistance in various types of cancer, including lung, breast and bladder cancer. The present study aimed to investigate whether KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) was associated with cisplatin (DDP) resistance in nasopharyngeal carcinoma (NPC). KCNQ1OT1, microRNA (miR)‑454 and ubiquitin specific peptidase 47 (USP47) expression levels were measured via reverse transcription‑quantitative PCR. 5‑8F/DDP and SUNE‑1/DDP cell viability and chemosensitivity were assessed by performing Cell Counting Kit‑8 assays. Colony forming and Transwell assays were conducted to assess the effect of the KCNQ1OT1/miR‑454/USP47 axis on DDP resistance in NPC cells. The association between miR‑454 and KCNQ1OT1 or USP47 was verified via bioinformatics analysis, dual‑luciferase reporter assays and RIP assays. KCNQ1OT1 and USP47 expression levels were significantly upregulated, whereas miR‑454 expression levels were significantly downregulated in DDP‑resistant NPC cells compared with parental NPC cells. KCNQ1OT1 knockdown promoted chemosensitivity in DDP‑resistant NPC cells (5‑8F/DDP and SUNE‑1/DDP), as indicated by significantly decreased cell proliferation, migration and invasion in the short hairpin RNA (sh)KCNQ1OT1 group compared with the sh‑negative control (NC) group. Moreover, miR‑454 was identified as a target of KCNQ1OT1. KCNQ1OT1 overexpression significantly reversed miR‑454 overexpression‑mediated effects on NPC cell viability and DDP resistance. Furthermore, the results indicated that miR‑454 directly targeted USP47. Compared with the shNC group, USP47 knockdown significantly suppressed NPC cell viability and DDP resistance, which was significantly reversed by co‑transfection with miR‑454 inhibitor. Furthermore, compared with the shNC group, KCNQ1OT1 knockdown significantly downregulated USP47 expression, which was significantly counteracted by miR‑454 knockdown. Collectively, the results of the present study indicated that KCNQ1OT1 enhanced DDP resistance in NPC cells via the miR‑454/USP47 axis, suggesting a potential therapeutic target for patients with DDP‑resistant NPC.

lncRNA FLVCR1‑AS1 drives colorectal cancer progression via modulation of the miR‑381/RAP2A axis

Colorectal cancer (CRC) is one of the most prevalent types of cancer globally. Long non-coding RNAs (lncRNAs) have been suggested to serve as vital regulators in CRC. lncRNA feline leukemia virus subgroup C receptor 1 antisense RNA 1 (FLVCR1-AS1) is closely associated with the tumorigenesis of various types of cancer. The aim of the present study was to investigate the molecular mechanisms of lncRNA FLVCR1-AS1 in CRC progression. The expression levels of FLVCR1-AS1, microRNA (miR)-381 and Ras-related protein 2a (RAP2A) were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A Kaplan-Meier analysis was performed to determine the overall survival rate of patients with CRC. Furthermore, cell viability, migration and invasion were assessed using Cell Counting Kit-8 (CCK-8) and Transwell assays. The interaction between genes was confirmed using dual-luciferase reporter and pull-down assays. The results demonstrated that FLVCR1-AS1 was upregulated in CRC tissues and cells, and increased FLVCR1-AS1 expression levels in patients with CRC were associated with poor prognosis. FLVCR1-AS1 knockdown significantly attenuated the viability, migration and invasion ability of CRC cells. In addition, the results confirmed that FLVCR1-AS1 directly binds with miR-381-3p, and that RAP2A is a direct target of miR-381-3p. The overexpression of FLVCR1-AS1 increased RAP2A expression levels. Functional assays revealed that miR-381 inhibitor or RAP2A overexpression attenuated the suppressive effects of FLVCR1-AS1 silencing on CRC cell viability, migration and invasion. Overall, the findings of the current study suggest that FLVCR1-AS1 promotes CRC progression via the miR-381/RAP2A pathway. These findings may provide a novel approach for CRC treatment.