LncRNA MBLN1-AS1 inhibits the progression of retinoblastoma through targeting miR-338-5p-Wnt/β-catenin signaling pathway

Non-coding RNA-based therapeutics in cancer therapy: An emphasis on Wnt/β-catenin control

Non-coding RNA transcripts are RNA molecules that have mainly regulatory functions and they do not encode proteins. microRNAs (miRNAs), lncRNAs and circRNAs are major types of this family and these epigenetic factors participate in disease pathogenesis, especially cancer that their abnormal expression may lead to cancer progression. miRNAs and lncRNAs possess a linear structure, whereas circRNAs possess ring structures and high stability. Wnt/β-catenin is an important factor in cancer with oncogenic function and it can increase growth, invasion and therapy resistance in tumors. Wnt upregulation occurs upon transfer of β-catenin to nucleus. Interaction of ncRNAs with Wnt/β-catenin signaling can determine tumorigenesis. Wnt upregulation is observed in cancers and miRNAs are able to bind to 3'-UTR of Wnt to reduce its level. LncRNAs can directly/indirectly regulate Wnt and in indirect manner, lncRNAs sponge miRNAs. CircRNAs are new emerging regulators of Wnt and by its stimulation, they increase tumor progression. CircRNA/miRNA axis can affect Wnt and carcinogenesis. Overall, interaction of ncRNAs with Wnt can determine proliferation rate, migration ability and therapy response of cancers. Furthermore, ncRNA/Wnt/β-catenin axis can be utilized as biomarker in cancer and for prognostic applications in patients.

LncRNA MBNL1-AS1 Suppresses Cell Proliferation and Metastasis of Pancreatic Adenocarcinoma through Targeting Carcinogenic miR-301b-3p

Pancreatic adenocarcinoma (PAAD) has been a huge challenge to public health due to its increasing incidence, frequent early metastasis, and poor outcome. The molecular basis of tumorigenesis and metastasis in PAAD is largely unclear. Here, we identified a novel tumor-suppressor long noncoding RNA (lncRNA) MBNL1-AS1, in PAAD and revealed its downstream mechanism. Quantitative real-time PCR (qRT-PCR) data showed that MBNL1-AS1 expression was significantly downregulated in PAAD tissues and cells, which was closely associated with metastasis and poor prognosis. Cell counting kit-8 (CCK-8) assay, transwell assay, and western blot verified that overexpression of MBNL1-AS1 suppressed cell proliferation, migration, and epithelial mesenchymal transformation (EMT) behavior in PAAD cells. By using a dual luciferase reporter gene system, we confirmed that miR-301b-3p was a direct target of MBNL1-AS1. Further mechanismic study revealed that upregulation of miR-301b-3p abolished the inhibitory effect of MBNL1-AS1 overexpression on cell proliferation, tumorigenesis, migration and EMT. Our results demonstrate that MBNL1-AS1 plays a tumor-suppressive role in PAAD mainly by downregulating miR-301b-3p, providing a novel therapeutic target for PAAD.

Long non-coding RNAs involved in retinoblastoma

INTRODUCTION

Retinoblastoma (RB) is the most common childhood tumor that can occur in the retina and develop in a sporadic or heritable form. Although various traditional treatment options have been used for patients with RB, identifying novel strategies for childhood cancers is necessary.

MATERIAL AND METHODS

Recently, molecular-based targeted therapies have opened a greater therapeutic window for RB. Long non-coding RNAs (lncRNAs) presented a potential role as a biomarker for the detection of RB in various stages.

CONCLUSION

LncRNAs by targeting several miRNA/transcription factors play critical roles in the stimulation or suppression of RB. In this review, we summarized recent progress on the functions of tumor suppressors or oncogenes lncRNAs in RB.

Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression

Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.

LncRNA MBNL1-AS1 Represses Proliferation and Cancer Stem-Like Properties of Breast Cancer through MBNL1-AS1/ZFP36/CENPA Axis

Background

Emerging studies have revealed long noncoding RNAs (lncRNAs) were key regulators of cancer progression. In this research, the expression and roles of MBNL1-AS1 were explored in breast cancer (BC).

Methods

In this study, the MBNL1-AS1 expression in breast cancer tissue, as well as in cell line, was studied by qRT-PCR assays. The effects of MBNL1-AS1 on proliferation and stemness were evaluated by MTT assays, colony formation assays, orthotopic breast tumor mice models, extreme limiting dilution analysis (ELDA), fluorescence in situ hybridization (FISH), flow cytometry assays, and sphere formation assays. Flexmap 3D assays were performed to show that MBNL1-AS1 downregulated the centromere protein A (CENPA) secretion in BC cells. Western blot, RNA pull-down assays, RNA immunoprecipitation (RIP) assays, and FISH were conducted to detect the mechanism.

Results

The results showed that the expression levels of MBNL1-AS1 were downregulated in breast cancer tissues and cell lines. In vitro and in vivo studies demonstrated that overexpression of MBNL1-AS1 markedly inhibited BC cells proliferation and stemness. RNA pull-down assay, RIP assay, western blot assay, and qRT-PCR assay showed that MBNL1-AS1 downregulated CENPA mRNA via directly interacting with Zinc Finger Protein 36 (ZFP36) and subsequently decreased the stability of CENPA mRNA. Restoration assays also confirmed that MBNL1-AS1 suppressed the CENPA-mediated proliferation and stemness in breast cancer cells.

Conclusions

The new mechanism of how MBNL1-AS1 regulates BC phenotype is elucidated, and the MBNL1-AS1/ZFP36/CENPA axis may be served as a therapeutic target for BC patients.

Circular RNA hsa_circ_0032683 inhibits the progression of hepatocellular carcinoma by sponging microRNA-338-5p

Recently, several studies have been conducted on circRNA (circular RNA). circRNA regulates gene expression and plays a vital role in the occurrence and development of various tumors. However, the role and mechanism of hsa_circ_0032683 in hepatocellular carcinoma (HCC) is not studied yet. In GEO (Gene Expression Omnibus) database, hsa_circ_0032683 expression was significantly lower in HCC tissues than in normal liver tissues. In vitro and in vivo functional tests revealed that hsa_circ_0032683 could inhibit HCC cells proliferation and promote their apoptosis. Mechanically, hsa_circ_0032683 primarily exists in the cytoplasm and competes with microRNA-338-5p (miR-338-5p) to regulate reticulon 4(RTN4). Our experiments revealed that hsa_circ_0032683 receded the proliferation ability of HCC via ceRNA (competing endogenous RNAs) mechanism, which provided potential biomarkers and therapeutic targets for HCC patients.Abbreviations: circRNAs: circular RNA; HCC: hepatocellular carcinoma; RTN4: reticulon 4; ceRNA: competing endogenous RNA; GEO: Gene Expression Omnibus; miRNA: microRNA; CSCD: Cancer-specific circRNA database; CRI: Circular RNA Interactome; TCGA: The Cancer Genome Atlas; qRT-PCR: quantitative real-time PCR; NEK9:NIMA-related kinase nine; CSMD1: CUB and Sushi multiple domains 1; Tob1: transducer of ERBB2, 1; miR: microRNA; sh: short hairpin; WT: wild type; MUT: mutant.

Roles of the microRNA‑338‑3p/NOVA1 axis in retinoblastoma

Retinoblastoma (RB) is an intraocular malignancy that mainly affects young children. Previous reports have demonstrated that mutations or the inactivation of the RB1 gene were the main cause of RB; however, disruption of the intracellular signaling pathways following deficiency of RB1 requires further investigation. Based on the Gene Expression Omnibus data and bioinformatics prediction, the present study aimed to investigate the microRNA (miR)-338-3p/neuro-oncological ventral antigen 1 (NOVA1) axis in RB. Subsequently, overexpression and knockdown of miR-338-3p and NOVA1, respectively, were performed to study the role of miR-338-3p/NOVA1 in the progression of the RB cells. The results demonstrated that overexpression of miR-338-3p significantly inhibited cell proliferation, migration and invasion, and promoted apoptosis of the RB cells. Moreover, knockdown of NOVA1 showed similar results. A dual-luciferase reporter assay and rescue experiments further confirmed the direct binding between miR-338-3p and NOVA1. Taken together, the results indicated that miR-338-3p acted as tumor suppressor by targeting the oncogene of NOVA1 in RB, which may serve as potential therapeutic targets in RB.