From junk to master regulators of invasion: lncRNA functions in migration, EMT and metastasis

A novel melatonin-regulated lncRNA suppresses TPA-induced oral cancer cell motility through replenishing PRUNE2 expression

The inhibitory effect of melatonin on cancer cell dissemination is well established, yet the functional involvement of lncRNAs in melatonin signaling remains poorly understood. In this study, we identified a melatonin-attenuated lncRNA acting as a potential melatonin-regulated oral cancer stimulator (MROS-1). Downregulation of MROS-1 by melatonin suppressed TPA-induced oral cancer migration through replenishing the protein expression of prune homolog 2 (PRUNE2), which functioned as a tumor suppressor in oral cancer. Melatonin-mediated MROS-1/PRUNE2 expression and cell motility in oral cancer were regulated largely through the activation of JAK-STAT pathway. In addition, MROS-1, preferentially localized in the nuclei, promoted oral cancer migration in an epigenetic mechanism in which it modulates PRUNE2 expression by interacting with a member of the DNA methylation machinery, DNA methyltransferase 3A (DNMT3A). Higher methylation levels of PRUNE2 promoter were associated with nodal metastases and inversely correlated with PRUNE2 expression in head and neck cancer. Collectively, these findings suggest that MROS-1, serving as a functional mediator of melatonin signaling, could predispose patients with oral cancer to metastasize and may be implicated as a potential target for antimetastatic therapies.

A Newly Identified lncBCAS1-4_1 Associated With Vitamin D Signaling and EMT in Ovarian Cancer Cells

Long noncoding RNAs (lncRNAs) were identified rapidly due to their important role in many biological processes and human diseases including cancer. 1α,25-dihydroxyvitamin D3 [1α,25(OH)₂D₃] and its analogues are widely applied as preventative and therapeutic anticancer agents. However, the expression profile of lncRNAs regulated by 1α,25(OH)₂D₃ in ovarian cancer remains to be clarified. In the present study, we found 606 lncRNAs and 102 mRNAs that showed differential expression (DE) based on microarray data. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that the DE genes were mainly enriched in TGF-β, MAPK, Ras, PI3K-Akt, and Hippo signaling pathways, as well as the vitamin D-related pathway. We further assessed the potential lncRNAs that linked vitamin D signaling with EMT, and lncBCAS1-4_1 was identified in the first time. Moreover, we found that the most upregulated lncBCAS1-4_1 showed 75% same transcripts with CYP24A1 (metabolic enzyme of 1α,25(OH)₂D₃). Finally, the lncBCAS1-4_1 gain-of-function cell model was established, which demonstrated that the knockdown of lncBCAS1-4_1 inhibited the proliferation and migration of ovarian cancer cells. Furthermore, lncBCAS1-4_1 could resist the antitumor effect of 1α,25(OH)₂D₃, which was associated with upregulated ZEB1. These data provide new evidences that lncRNAs served as a target for the antitumor effect of 1α,25(OH)₂D₃.

Disregulations of PURPL and MiR-338-3p Could Serve As Prognosis Biomarkers for Epithelial Ovarian Cancer

Objective: The present study aimed to explore the expressions of long noncoding RNA (lncRNA) p53 upregulated regulator of p53 levels (PURPL) in different ovarian tissues, and to evaluate the significance of disregulations of PURPL and microRNA-338-3p (miR-338-3p) in epithelial ovarian cancer (EOC).

Methods: The expressions of PURPL in ovarian cancer, the relations between PURPL and the prognosis of ovarian cancer, and the relation between PURPL and miR-338-3p were queried in multiple biomedical databases. Real-time PCR was performed to detect the expressions of PURPL in different ovarian tissues. Logistic regression analysis was used to analyze the risk factors of recurrence and death. Kaplan-Meier analysis was implemented to evaluate the relations between PURPL and miR-338-3p expressions and the survival of ovarian cancer.

Results: PURPL could target miR-338-3p, PURPL were upregulated in ovarian cancer tissues, upregulation of PURPL in ovarian cancer was negatively related with the recurrence free survival (RFS) and overall survival (OS), which were indicated by biomedical databases query. Our data showed upregulations of PURPL were noted in ovarian cancer tissues. Higher expressions of PURPL were associated with more advanced FIGO stage and developed lymph node metastasis in epithelial ovarian cancer. Upregulation of PURPL was related with the recurrence (P=0.002, OR=21.482, 95%CI: 3.457~94.251) and death (P=0.004, OR=35.643, 95%CI: 2.453~84.359) of ovarian cancer patient. PURPL expressions were negatively correlated to miR-338-3p expressions in different ovarian tissues (r = -0.968, P<0.0001). Poor RFS (χ²=19.410, P=0.0002) and OS (χ²=17.600, P=0.0005) were found in patients with high level PURPL and low level miR-338-3p expressions.

Conclusions: Upregulation of PURPL and downregulation of miR-338-3p were related with the poor RFS and OS of ovarian cancer, which indicated disregulations of PURPL and miR-338-3p could serve as prognosis biomarkers for epithelial ovarian cancer.

IFNG-AS1 and MAF4 long non-coding RNAs are upregulated in acute leukemia patients who underwent bone marrow transplantation

PURPOSE OF THE STUDY

Acute graft versus host disease (aGVHD) is an immune-mediated reaction that results in impaired immune and body function after allogeneic hematopoietic stem cell transplantation (allo-HSCT). lncRNAs have been discovered as particular T cell regulators, and alloreactive T cells have been known as a critical factor in aGVHD. As a result, we investigated the importance of lnc-MAF4 and IFNG-AS1 expression levels in aGVHD patients versus non-aGVHD patients.

MATERIAL AND METHODS

This research included 38 patients with hematological disorders who were undergoing primary allo-HSCT. Human identical siblings or unrelated donors were used to collect stem cell. Samples were taken within days 0, 7, 14, 28, and 52±8 after transplantation. The expression of lncRNA levels was measured using the QRT-PCR technique. And the data were analyzed using GraphPad Prism 6 RESULTS: Our data revealed that LncRNA MAF4 and INFG-AS1 expression levels in aGVHD were not significantly different compared to the non-GVHD group immediately after transplantation, nor at day 7 or 14. However, the aGVHD group showed an overt up-regulation of the two lncRNAs on samples taken at day 28 and 52±8 compared to non-GVHD patients.

DISCUSSION

Since the intracellular pathway of these lncRNAs shows a direct relationship with the IFNγ cytokine production resulting in differentiation to TH1 cells and inhibition of differentiation to TH2 cells, they can be, therefore, considered as suitable molecular candidates for the prediction of aGVHD in patients receiving HSCT.

LncRNA TCONS_00023297 Regulates the Balance of Osteogenic and Adipogenic Differentiation in Bone Marrow Mesenchymal Stem Cells and the Coupling Process of Osteogenesis and Angiogenesis

Long noncoding RNA (lncRNA) is a noncoding RNA with a length of more than 200 bases. It plays an important role in the occurrence and development of diseases. Research on lncRNAs has received increasing attention. Bone is an important organ of the human body. As the population ages, the incidence of osteoporosis gradually increases. The mechanism of action of lncRNAs in the development of osteoporosis is unclear. The imbalance between osteogenic and adipogenic differentiation in bone marrow mesenchymal stem cells (hBMSCs) and the coupling process of osteogenesis and angiogenesis plays an important role in the development of osteoporosis. Therefore, this study focused on the mechanism by which lncRNAs regulate the osteogenic differentiation of bone marrow mesenchymal stem cells and the mechanism of action of lncRNAs in bone metabolism. The expression of lncRNAs in the osteogenic differentiation of hBMSCs was detected by lncRNA microarray. Real-time quantitative PCR was used to detect the expression changes of lncRNA and osteogenic genes during hBMSC osteogenic and adipogenic differentiation. The ceRNA mechanisms were detected by RIP and luciferase reporter gene assays. The effect of lncRNAs on the osteogenesis–angiogenesis coupling process was detected by Transwell assays. TCONS_00023297 increased expression during osteogenic differentiation; TCONS_00023297 overexpression promoted osteogenic differentiation of hBMSCs; BMP2 regulated TCONS_00023297 expression in a concentration- and time-dependent manner; TCONS_00023297 regulated miR-608 via a ceRNA mechanism; TCONS_00023297 inhibited hBMSC adipogenic differentiation; and TCONS_00023297 promoted VEGF secretion by hBMSCs. TCONS_00023297 regulates osteogenic differentiation, adipogenic differentiation, and osteogenic–angiogenic coupling of hBMSCs via the TCONS_00023297/miR-608/RUNX2/SHH signaling axis.

Linc01559 Served as a Potential Oncogene and Promoted Resistance of Hepatocellular Carcinoma to Oxaliplatin by Directly Sponging miR-6783-3p

BACKGROUND

Oxaliplatin (L-OHP)-based chemotherapy, such as FOLFOX4 (5-fluorouracil, leucovorin, and L-OHP), improves the prognosis of patients with late-stage Hepatocellular Carcinoma (HCC). However, the development of resistance to L-OHP leads to the failure of chemotherapy. The aim of this study was to investigate the role of linc01559 and miR-6783-3p in regulating resistance to L-OHP.

METHODS

Quantitative reverse transcription-polymerase chain reaction was used to determine the expression profile. The Cell Counting Kit-8 test and wound healing assay were also used. Dual-luciferase reporter gene assay, RNA pull-down assay, and RNA immunoprecipitation were used to evaluate the interaction between linc01559 and miR-6783-3p.

RESULT

linc01559 expression was associated with response to FOLFOX4, as well as miR-1343-3p and miR- 6783-3p expression in vivo. A nomogram, including linc01559 and miR-1343-3p, precisely and accurately predicted the overall survival of patients with HCC. Regarding the in vitro tests, linc01559 showed higher expression in L-OHP-resistant cell lines, whereas miR-6783-3p was downregulated. Knockdown of linc01559 led to decreased proliferation and migration ability, and increased expression of miR-6783-3p; however, it did not influence the expression of miR-1343-3p. We also found that linc01559 directly interacted with miR-6783-3p. Furthermore, linc01559 and miR-6783-3p regulated the viability of L-OHP-resistant cells following treatment with L-OHP.

CONCLUSION

linc01559 promoted the proliferation of HCC by sponging miR-6783-3p. This suggests that linc01559/miR-6783-3p may be key factors in regulating resistance and response to L-OHP. Moreover, they may be potential therapeutic targets for improving sensitivity to L-OHP in patients with HCC.

Long non-coding RNA exploration for mesenchymal stem cell characterisation

BACKGROUND

The development of RNA sequencing (RNAseq) and the corresponding emergence of public datasets have created new avenues of transcriptional marker search. The long non-coding RNAs (lncRNAs) constitute an emerging class of transcripts with a potential for high tissue specificity and function. Therefore, we tested the biomarker potential of lncRNAs on Mesenchymal Stem Cells (MSCs), a complex type of adult multipotent stem cells of diverse tissue origins, that is frequently used in clinics but which is lacking extensive characterization.

RESULTS

We developed a dedicated bioinformatics pipeline for the purpose of building a cell-specific catalogue of unannotated lncRNAs. The pipeline performs ab initio transcript identification, pseudoalignment and uses new methodologies such as a specific k-mer approach for naive quantification of expression in numerous RNAseq data. We next applied it on MSCs, and our pipeline was able to highlight novel lncRNAs with high cell specificity. Furthermore, with original and efficient approaches for functional prediction, we demonstrated that each candidate represents one specific state of MSCs biology.

CONCLUSIONS

We showed that our approach can be employed to harness lncRNAs as cell markers. More specifically, our results suggest different candidates as potential actors in MSCs biology and propose promising directions for future experimental investigations.

Regulatory Mechanisms and Functional Roles of Hypoxia-Induced Long Non-Coding RNA MTORT1 in Breast Cancer Cells

Long non-coding RNAs (lncRNAs) have been found to participate in multiple genetic pathways in cancer. Also, mitochondria-associated lncRNAs have been discovered to modulate mitochondrial function and metabolism. Previously, we identified oxygen-responsive lncRNAs in MCF-7 breast cancer cells under different oxygen concentrations. Among them, a novel mitochondria-encoded lncRNA, mitochondrial oxygen-responsive transcript 1 (MTORT1), was chosen for further investigation. Nuclear, cytoplasmic, and mitochondrial fractionation assays were performed to evaluate the endogenous expression levels of MTORT1 in breast cancer cells. In vitro proliferation and migration assays were conducted to investigate the functions of MTORT1 in breast cancer cells by knockdown of MTORT1. RNA immunoprecipitation and luciferase reporter assays were used to examine the physical binding between MTORT1 and microRNAs. Our results showed that MTORT1 had low endogenous expression levels in breast cancer cells and was mainly located in the mitochondria. Knockdown of MTORT1 enhanced cell proliferation and migration, implying a tumor suppressor role of this novel mitochondrial lncRNA. MTORT1 served as sponge of miR-26a-5p to up-regulate its target genes, CREB1 and STK4. Our findings shed some light on the characterization, function, and regulatory mechanism of the novel hypoxia-induced mitochondrial lncRNA MTORT1, which functions as a microRNA sponge and may inhibit breast cancer progression. These data suggest that MTORT1 may be a candidate for therapeutic targeting of breast cancer progression.

Tumor Inhibitory Effect of Long Non-coding RNA LOC100505817 on Gastric Cancer

Gastric cancer (GC) is one of the major malignancies worldwide. Emerging evidence has revealed the potential involvement of long noncoding RNA (lncRNA) in human genetic disorders and cancer, but the role of LOC100505817 remains unknown. Thus, in this study, we isolated tissues from GC patients to characterize the functional importance of LOC100505817 in GC tumorigenesis. We also proposed a hypothesis that the regulation of Wnt/β-catenin pathway by LOC100505817 was regulated by miR-20a-mediated WT1. After the collection of cancer tissues and adjacent tissues were obtained from GC patients, expression of LOC100505817, Wnt/β-catenin pathway- and EMT-related genes was quantified. Ectopic expression and knockdown experiments were applied in order to investigate the protective role of LOC100505817 in the progression of GC. Subsequently, cell viability, flow cytometry for apoptosis and cell cycle were detected via CCK-8, while migration and invasion were determined using scratch test and Transwell assay respectively. Then interactions among LOC100505817, miR-20a and WT1 were explored by dual luciferase reporter gene assay, RNA pull down assay and RNA binding protein immunoprecipitation (RIP) assay. The results found poor expression LOC100505817 was poorly expressed in GC cells and tissues. Overexpressed LOC100505817 resulted in the significant reduction of cell proliferation, migration and invasion as well as the expression of Wnt2b, β-catenin, CyclinD1, N-cadherin, Vimentin and snail, while increased cell apoptosis along with the expression of E-cadherin. Wnt/β-catenin pathway and EMT in GC cells were suppressed by LOC100505817 through miR-20a-inhibted WT1. In summary, our results provided evidence suggesting that LOC100505817 inhibits GC through LOC100505817-mediated inhibition of Wnt/β-catenin pathway, that leads to the overall restraining of GC cell proliferation, migration and invasion through miR-20a-reduced WT1.

LncRNA testis-specific transcript, Y-linked 15 (TTTY15) promotes proliferation, migration and invasion of colorectal cancer cells via regulating miR-29a-3p/DVL3 axis

BACKGROUND

Long non-coding RNA testis-specific transcript, Y-linked 15 (TTTY15) is oncogenic in prostate cancer, however its expression and function in colorectal cancer remain largely unknown.

METHODS

Paired colorectal cancer samples/normal tissues were collected, and the expression levels of TTTY15, miR-29a-3p and disheveled segment polarity protein 3 (DVL3) were examined by quantitative real-time polymerase chain reaction (qRT-PCR); TTTY15 shRNA and overexpression plasmids were transfected into HT29 and HCT-116 cell lines using lipofectamine reagent, respectively; the proliferation and colony formation were detected by CCK-8 assay and plate colony formation assay; qRT-PCR and Western blot were used to analyze the changes of miR-29a-3p and DVL3; dual-luciferase reporter gene assay was used to determine the regulatory relationships between miR-29a-3p and TTTY15, miR-29a-3p and DVL3.

RESULTS

TTTY15 was significantly up-regulated in cancerous tissues of colorectal cancer samples, positively correlated with the expression of DVL3, while negatively correlated with the expression of miR-29a-3p. After TTTY15 shRNAs were transfected into colorectal cancer cells, the proliferation and metastasis of cancer cells were significantly inhibited, while TTTY15 overexpression had opposite biological effects. TTTY15 shRNA could reduce the expression of DVL3 on both mRNA and protein levels, and the luciferase activity of TTTY15 sequence was also inhibited by miR-29a-3p. DVL3 was also validated as a target gene of miR-29a-3p, and it could be repressed by miR-29a-3p mimics or TTTY15 shRNA.

CONCLUSION

TTTY15 is abnormally upregulated in colorectal cancer tissues, and it can modulate the proliferation and metastasis of colorectal cancer cells. It functions as the ceRNA to regulate the expression of DVL3 by sponging miR-29a-3p.

Knockdown of long non-coding RNA RP11-297P16.3 inhibits the migration and invasion of laryngeal squamous carcinoma cells

PURPOSE

Laryngeal cancer has a poor prognosis when progressing to an advanced stage with limited treatment options. Therefore, understanding the underlying mechanisms is important to identify novel treatment targets. Long non-coding RNAs (lncRNAs) have been shown to play oncogenic roles in cancer, including in laryngeal cancer. We previously discovered that the lncRNA RP11-297P16.3 is overexpressed in laryngeal squamous cell carcinoma (LSCC) based on RNA-sequencing data. Therefore, the aim of the present study was to investigate the effects of knockdown of RP11-297P16.3 on the migration and invasion of LSCC cells, and the significance of these effects.

METHODS

Six methods were employed to assess the function of RP11-297P16.3 including gene silencing, RT-PCR, the 5-Ethynyl-20-deoxyuridine (EdU) staining assay, Scratch wound-healing assay, transwell assay, and Western blot.

RESULTS

The results show that the expression of RP11-297P16.3 in the si-lncRNA group was significantly decreased compared with those in the BC (blank control) and NC (negative control) groups. Moreover, knockdown of RP11-297P16.3 significantly inhibited the migration and invasion of LSCC cells but had no effect on cell proliferation. The protein expression of N-cadherin and vimentin was notably decreased after RP11-297P16.3 knockdown; whereas, the protein expression of cadherin was significantly increased CONCLUSION: These results suggested that RP11-297P16.3 may inhibit the migration and invasion of LSCC cells by regulating the epithelial-mesenchymal transition process, suggesting that RP11-297P16.3 is a potential new target for treating LSCC.

PD-L1 lncRNA splice isoform promotes lung adenocarcinoma progression via enhancing c-Myc activity

BACKGROUND

Although using a blockade of programmed death-ligand 1 (PD-L1) to enhance T cell immune responses shows great promise in tumor immunotherapy, the immune-checkpoint inhibition strategy is limited for patients with solid tumors. The mechanism and efficacy of such immune-checkpoint inhibition strategies in solid tumors remains unclear.

RESULTS

Employing qRT-PCR, Sanger sequencing, and RNA BaseScope analysis, we show that human lung adenocarcinoma (LUAD) all produce a long non-coding RNA isoform of PD-L1 (PD-L1-lnc) by alternative splicing, regardless if the tumor is positive or negative for the protein PD-L1. Similar to PD-L1 mRNA, PD-L1-lnc in various lung adenocarcinoma cells is significantly upregulated by IFNγ. Both in vitro and in vivo studies demonstrate that PD-L1-lnc increases proliferation and invasion but decreases apoptosis of lung adenocarcinoma cells. Mechanistically, PD-L1-lnc promotes lung adenocarcinoma progression through directly binding to c-Myc and enhancing c-Myc transcriptional activity.

CONCLUSIONS

In summary, the PD-L1 gene can generate a long non-coding RNA through alternative splicing to promote lung adenocarcinoma progression by enhancing c-Myc activity. Our results argue in favor of investigating PD-L1-lnc depletion in combination with PD-L1 blockade in lung cancer therapy.

Long noncoding RNA (lncRNA) EIF3J-DT induces chemoresistance of gastric cancer via autophagy activation

Chemotherapy is currently the main treatment for unresectable or advanced postoperative gastric cancers. However, its efficacy is negatively affected by the occurrence of chemoresistance, which severely affects patient prognosis. Recently, dysregulation in autophagy has been suggested as a potential mechanism for chemoresistence, and long noncoding RNA (lncRNA) also shows its regulatory role in cancer drug resistance. Using RNA sequencing, we found that lncRNA EIF3J-DT was highly expressed in drug-resistant gastric cancer cells. In-vitro and in-vivo experiments showed that EIF3J-DT activated autophagy and induced drug resistance in gastric cancer cells by targeting ATG14. Bioinformatics and experimental results showed that EIF3J-DT regulated the expression of ATG14 through direct binding to enhance stabilization of ATG14 mRNA and via blocking the degradation of ATG14 mRNA through competitively binding with microRNA (miRNA) MIR188-3p. Therefore, EIF3J-DT increased the expression of ATG14, contributing to activation of autophagy and chemoresistance. Furthermore, it was confirmed that EIF3J-DT and ATG14 were highly expressed in gastric cancer patients resistant to chemotherapy, and this was closely associated with patient prognosis. In conclusion, EIF3J-DT is involved in the regulation of autophagy and chemoresistance in gastric cancer cells by targeting ATG14. It may be a suitable new target for enhancing chemosensitivity and improving prognosis.Abbreviations: 3-MA: 3-methyladenine; 5-Fu: 5-fluorouracil; ATG: autophagy related; C-CASP3: cleaved caspase 3; C-CASP7: cleaved caspase 7; C-PARP: cleaved PARP; CQ: chloroquine; CR: complete response; DIG: digoxigenin; ESR1: estrogen receptor 1; FBS: fetal bovine serum; FISH: fluorescence in situ hybridization; IHC: immunohistochemistry; ISH: in situ hybridization; lncRNA: long noncoding RNA; miRNA: microRNA; MUT: mutant; NC: negative control; OXA: oxaliplatin; PBS: phosphate-buffered saline; PD: progressive disease; PFA: paraformaldehyde; PR: partial response; qPCR: quantitative polymerase chain reaction; RAPA: rapamycin; SD: stable disease; TEM: transmission electron microscopy; WT: wild type.

Loss of lncRNA SNHG8 promotes epithelial-mesenchymal transition by destabilizing CDH1 mRNA

Long non-coding RNAs (lncRNAs) are widely involved in a variety of biological processes, including epithelial-mesenchymal transition (EMT). In the current study, we found that lncRNA small nucleolar RNA host gene 8 (SNHG8) was tightly correlated with EMT-associated gene signatures, and was down-regulated by Zinc finger E-box-binding homeobox 1 (ZEB1) during EMT progress. Functionally, knockdown of SNHG8 induced EMT in epithelial cells, through destabilizing the CDH1 mRNA dependent on a 17-nucleotide sequence shared by SNHG8 and CDH1. In addition, analysis with public database showed that SNHG8 tended to be down-regulated in different cancer types and the lower expression of SNHG8 predicted poorer prognosis. Taken together, our study reports a ZEB1-repressed lncRNA SNHG8 which is important for stabilizing CDH1 mRNA, thereby maintaining the epithelial status of epithelial cells.

hnRNPK-regulated LINC00263 promotes malignant phenotypes through miR-147a/CAPN2

Malignant characteristics of cancers, represented by rapid cell proliferation and high metastatic potential, are a major cause of high cancer-related mortality. As a multifunctional RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNPK) is closely associated with cancer progression in various types of cancers. In this study, we sought to identify hnRNPK-regulated long intergenic non-coding RNAs (lincRNAs) that play a critical role in the regulation of cancer malignancy. We found that hnRNPK controlled malignant phenotypes including invasiveness, proliferation, and clonogenicity. RNA sequencing and functional studies revealed that LINC00263, a novel target of hnRNPK, is involved in the oncogenic functions of hnRNPK. Knockdown of LINC00263 mitigated the malignant capabilities. Conversely, increased malignant phenotypes were observed in LINC00263-overexpressing cells. Since LINC00263 was mainly localized in the cytosol and highly enriched in Argonaute 2-immunoprecipitation (Ago2-IP), we hypothesized that LINC00263 acts as a competitive endogenous RNA (ceRNA), and thus sought to identify LINC00263-associated microRNAs. Using small RNA sequencing followed by antisense oligonucleotide pull-down, miR-147a was selected for further study. We found that miR-147a negatively regulates LINC00263 via direct interaction, thus suppressing malignant capabilities. Moreover, knockdown of hnRNPK and LINC00263 upregulated miR-147a, indicating that LINC00263 serves as a ceRNA for miR-147a. By analyzing RNA sequencing data and miRNA target prediction, calpain 2 (CAPN2) was identified as a putative target of miR-147a. Ago2-IP and luciferase reporter assay revealed that miR-147a suppressed CAPN2 expression by directly binding to the 3′UTR of CAPN2 mRNA. In addition, we found that the weakened malignant capabilities following knockdown of hnRNPK or LINC00263 were restored by miR-147a inhibition or CAPN2 overexpression. Furthermore, our findings were validated in various other types of cancer cells including lung cancer, colorectal cancer, neuroblastoma, and melanoma. Collectively, we demonstrate that hnRNPK-regulated LINC00263 plays an important role in cancer malignancy by acting as a miR-147a decoy and thus upregulating CAPN2.

Regulation of Long Non-Coding RNAs by Plant Secondary Metabolites: A Novel Anticancer Therapeutic Approach

Simple Summary

Cancer is caused by the rapid and uncontrolled growth of cells that eventually lead to tumor formation. Genetic and epigenetic alterations are among the most critical factors in the onset of carcinoma. Phytochemicals are a group of natural compounds that play an essential role in cancer prevention and treatment. Long non-coding RNAs (lncRNAs) are potential therapeutic targets of bioactive phytochemicals, and these compounds could regulate the expression of lncRNAs directly and indirectly. Here, we critically evaluate in vitro and in vivo anticancer effects of phytochemicals in numerous human cancers via regulation of lncRNA expression and their downstream target genes.

Abstract

Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs that play an essential role in various cellular activities, such as differentiation, proliferation, and apoptosis. Dysregulation of lncRNAs serves a fundamental role in the progression and initiation of various diseases, including cancer. Precision medicine is a suitable and optimal treatment method for cancer so that based on each patient’s genetic content, a specific treatment or drug is prescribed. The rapid advancement of science and technology in recent years has led to many successes in this particular treatment. Phytochemicals are a group of natural compounds extracted from fruits, vegetables, and plants. Through the downregulation of oncogenic lncRNAs or upregulation of tumor suppressor lncRNAs, these bioactive compounds can inhibit metastasis, proliferation, invasion, migration, and cancer cells. These natural products can be a novel and alternative strategy for cancer treatment and improve tumor cells’ sensitivity to standard adjuvant therapies. This review will discuss the antineoplastic effects of bioactive plant secondary metabolites (phytochemicals) via regulation of expression of lncRNAs in various human cancers and their potential for the treatment and prevention of human cancers.

Roles of Non-Coding RNAs in Cervical Cancer Metastasis

Metastasis remains to be a huge challenge in cancer therapy. The mechanism underlying cervical cancer metastasis is not well understood and needs to be elucidated. Recent studies have highlighted the diverse roles of non-coding RNAs in cancer progression and metastasis. Increasing numbers of miRNAs, lncRNAs and circRNAs are found to be dysregulated in cervical cancer, associated with metastasis. They have been shown to regulate metastasis through regulating metastasis-related genes, epithelial-mesenchymal transition, signaling pathways and interactions with tumor microenvironment. Moreover, miRNAs can interact with lncRNAs and circRNAs respectively during this complex process. Herein, we review literatures up to date involving non-coding RNAs in cervical cancer metastasis, mainly focus on the underlying mechanisms and highlight the interaction network between miRNAs and lncRNAs, as well as circRNAs. Finally, we discuss the therapeutic prospects.

Long Noncoding RNAs as Innovative Urinary Diagnostic Biomarkers

The characterization of circulating tumor cells (CTCs) is now widely studied as a promising source of cancer-derived biomarkers because of their role in tumor formation and progression. However, CTCs analysis presents some limitations and no standardized method for CTCs isolation from urine has been defined so far. In fact, besides blood, urine represents an ideal source of noninvasive biomarkers, especially for the early detection of genitourinary tumors. Besides CTCs, long noncoding RNAs (lncRNAs) have also been proposed as potential noninvasive biomarkers, and the evaluation of the diagnostic accuracy of urinary lncRNAs has dramatically increased over the last years, with many studies being published. Therefore, this review provides an update on the clinical utility of urinary lncRNAs as novel biomarkers for the diagnosis of bladder and prostate cancers.

Novel lncRNA LINC00941 Promotes Proliferation and Invasion of Colon Cancer Through Activation of MYC

Purpose

We conducted the study to elucidate how LncRNA LINC00941 affects colon cancer progression and its possible regulatory mechanism.

Methods

The expression level of LINC00941 in colon cancer tissues and cells was detected by qRT-PCR. The function of LINC00941 on colon cancer cell proliferation, migration, and invasion was detected by CCK-8 and Transwell assay respectively. The target interactions among LINC00941, miR-205-5p, and MYC were further confirmed by dual-luciferase reporter gene assays and RNA pull-down experiments. Meanwhile, in vivo experiments were carried out to study the role of LINC00941 in the xenotransplantation model.

Results

LINC00941 expression level was elevated in colon cancer tissues and cells. LINC00941 overexpression accelerated proliferation, migration, and invasion of colon cancer cells, while the LINC00941 knockdown showed the opposite results. In addition, LINC00941 regulated the expression of MYC by sponging miR-205-5p as a competitive endogenous RNA, and miR-205-5p knockdown reversed the tumor inhibition of LINC00941 knockdown on colon cancer cells. Xenograft model assay confirmed that LINC00941 silencing could inhibit colon cancer cell growth and metastasis.

Conclusion

LINC00941 may markedly promote colon cancer progression by acting on the miR-205-5p/MYC axis as a ceRNA, which offers novel clues for lncRNA to guide the treatment and prognosis of colon cancer.

LncRNA HOTAIRM1 knockdown inhibits cell glycolysis metabolism and tumor progression by miR-498/ABCE1 axis in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is a major contributor of cancer-related mortality. Long non-coding RNAs (lncRNAs) are indicated to participate in the pathogenesis of NSCLC.

OBJECTIVE

In this research, the effects of lncRNA HOXA transcript antisense RNA, myeloid-specific 1 (HOTAIRM1) on NSCLC progression and underlying mechanism were revealed.

METHODS

The expression levels of HOTAIRM1 and microRNA-498 (miR-498) were detected by quantitative real time polymerase chain reaction (qRT-PCR) in NSCLC tissues, cells or exosomes. The protein expression of CD63, CD81, hexokinase 2 (HK2) and ATP binding cassette subfamily E member 1 (ABCE1) was determined by western blot. Cell viability, apoptosis, migration and invasion were investigated by cell counting kit-8 (CCK-8), flow cytometry, transwell migration and invasion assays, respectively. Cell glycolysis metabolism was revealed by glucose uptake and lactate production assays and western blot analysis. The binding relationship between miR-498 and HOTAIRM1 or ABCE1 was predicted by DIANA-LncBase v2 and starBase online database, and identified by dual-luciferase reporter assay. The effects of HOTAIRM1 on NSCLC growth in vivo were revealed by in vivo tumor formation assay.

RESULTS

HOTAIRM1 expression was dramatically upregulated, whereas miR-498 expression was significantly downregulated in NSCLC tissues cells or exosomes as compared to control groups. Mechanistically, HOTAIRM1 knockdown repressed cell viability, migration, invasion and glycolysis metabolism, whereas induced cell apoptosis in NSCLC; however, miR-498 inhibitor hindered these effects. Functionally, HOTAIRM1 functioned as a sponge of miR-498 and miR-498 targeted ABCE1. In addition, HOTAIRM1 silencing inhibited NSCLC growth in vivo by downregulating ABCE1 and upregulating miR-498 expression.

CONCLUSIONS

HOTAIRM1 knockdown repressed cell glycolysis metabolism and tumor development by reducing ABCE1 expression through sponging miR-498 in NSCLC, which provided a theoretical basis for further studying NSCLC progression.

The Roles of circRNAs in Liver Cancer Immunity

Circular RNAs (circRNAs) are stable covalently closed non-coding RNAs (ncRNAs). Many studies indicate that circRNAs are involved in the pathological and physiological processes of liver cancer. However, the functions of circRNAs in liver cancer immunity are less known. In this review, we summarized the functions of circRNAs in liver cancer, including proliferative, metastasis and apoptosis, liver cancer stemness, cell cycle, immune evasion, glycolysis, angiogenesis, drug resistance/sensitizer, and senescence. Immune escape is considered to be one of the hallmarks of cancer development, and circRNA participates in the immune escape of liver cancer cells by regulating natural killer (NK) cell function. CircRNAs may provide new ideas for immunotherapy in liver cancer.

Long non-coding RNA signatures as predictors of prognosis in thyroid cancer: a narrative review

Thyroid cancer (TC) is the most common endocrine malignancy, with high incidence rates in recent decades. Most TC cases have good prognoses, but a high risk of recurrence and metastases poses challenges, especially for patients with high-risk factors. Currently used prognostic markers for TC involve a combination of genetic factors and overexpressed proteins. Long non-coding RNAs (lncRNAs) regulate several integral biologic processes by playing key roles in the transcription of several downstream targets maintaining cellular behavior. Prior studies have revealed that lncRNAs promote tumor cell proliferation, invasion, metastasis, and angiogenesis, making them important targets for therapeutic intervention in cancer. While the exact molecular mechanisms underlying the role of lncRNAs in modulating TC progression and recurrence is still unclear, it is important to note that some lncRNAs are upregulated in certain cancers, while others are downregulated. In the present study, we review several key lncRNAs, their association with cancer progression, and the important roles they may play as tumor suppressors or tumor promoters in tumorigenesis. We discuss the potential mechanisms of lncRNA-mediated pathogenesis that can be targeted for the treatment of TC, the existing and potential benefits of using lncRNAs as diagnostic and prognostic measures for cancer detection, and tumor burden in patients.

Long non-coding RNAs in recurrent ovarian cancer: Theranostic perspectives

Nearly 70% of ovarian cancer (OC) patients experience recurrence within the first 2 years after initial treatment. Emerging evidence indicates that long non-coding RNAs (lncRNAs) play a pivotal role in the pathogenesis of OC progression, resistance to therapy and recurrent OC (ROC). Transcriptome profiling studies have reported differential expression patterns of lncRNAs in OC which are related to increased cell invasion, metastasis and drug resistance. In this review, we highlighted the roles of lncRNAs in OC progression and outlined the potential molecular mechanisms by which lncRNAs impact on ROC. Recent advances using lncRNAs as potential biomarkers for screening, detection, prediction, response to therapy and as therapeutic targets are discussed.

RNA stabilization by a poly(A) tail 3'-end binding pocket and other modes of poly(A)-RNA interaction

Polyadenylate [poly(A)] tail addition to the 3' end of a wide range of RNAs is a highly conserved modification that plays a central role in cellular RNA function. Elements for nuclear expression (ENEs) are cis-acting RNA elements that stabilize poly(A) tails by sequestering them in RNA triplex structures. A crystal structure of a double ENE from a rice hAT transposon messenger RNA complexed with poly(A)₂₈ at a resolution of 2.89 angstroms reveals multiple modes of interaction with poly(A), including major-groove triple helices, extended minor-groove interactions with RNA double helices, a quintuple-base motif that transitions poly(A) from minor-groove associations to major-groove triple helices, and a poly(A) 3'-end binding pocket. Our findings both expand the repertoire of motifs involved in long-range RNA interactions and provide insights into how polyadenylation can protect an RNA's extreme 3' end.

Steps in metastasis: an updated review

Metastasis is the most complex and deadly event. Tumor-stromal interface is a place where invasion of tumor cells in the form of single-cell or collective migration occurs, with the latter being less common but more efficient. Initiation of metastasis relies on the tumor cell cross-talking with stromal cells and taking an epithelial-mesenchymal transition (EMT) in single cells, and a hybrid EMT in collective migratory cells. Stromal cross-talking along with an abnormal leaky vasculature facilitate intravasation of tumor cells, here the cells are called circulating tumor cells (CTCs). Tumor cells isolated from the primary tumor exploit several mechanisms to maintain their survival including rewiring metabolic demands to use sources available within the new environments, avoiding anoikis cell death when cells are detached from extracellular matrix (ECM), adopting flow mechanic by acquiring platelet shielding and immunosuppression by negating the activity of suppressor immune cells, such as natural killer (NK) cells. CTCs will adhere to the interstituim of the secondary organ/s, within which the newly arrived disseminative tumor cells (DTCs) undergo either dormancy or proliferation. Metastatic outgrowth is under the influence of several factors, such as the activity of macrophages, impaired autophagy and secondary site inflammatory events. Metastasis can be targeted by multiple ways, such as repressing the promoters of pre-metastatic niche (PMN) formation, suppressing environmental contributors, such as hypoxia, oxidative and metabolic stressors, and targeting signaling and cell types that take major contribution to the whole process. These strategies can be used in adjuvant with other therapeutics, such as immunotherapy.

Multifaceted Roles of Long Non-coding RNAs in Head and Neck Cancer

The majority of RNA transcripts are non-coding RNA (ncRNA) transcripts with lengths exceeding 200 nucleotides that are not translated into protein. Unlike microRNAs (miRNAs), long ncRNAs (lncRNAs) are not confined to a single mechanism of action but have a large and diverse role in biological processes as they can function as transcription regulators, decoys, scaffolds, and enhancer RNAs. Currently, many lncRNA molecules are under investigation for their role in tumorigenesis, metastasis, and prognosis in different types of cancer. This review not only summarizes the characteristics and functions of lncRNAs but also discusses the therapeutic implications and applications of lncRNAs with roles associated with head and neck cancer. Our aim is to pinpoint the potential way to perturb specific lncRNAs for future therapeutic use.

Long Non-Coding RNAs: Potential Biomarkers and Targets for Hepatocellular Carcinoma Therapy and Diagnosis

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Increasing studies showed that long non-coding RNAs (lncRNAs), a novel class of RNAs that are greater than 200 nucleotides in length but lack the ability to encode proteins, exert crucial roles in the occurrence and progression of HCC. LncRNAs promote the proliferation, migration, invasion, autophagy, and apoptosis of tumor cells by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can be used as biomarkers to predict the efficacy of HCC treatment strategies, such as surgery, radiotherapy, chemotherapy, and immunotherapy, and as a potential individualized tool for HCC diagnosis and treatment. In this review, we overview up-to-date findings on lncRNAs as potential biomarkers for HCC surgery, radiotherapy, chemotherapy resistance, target therapy, and immunotherapy, and discuss the potential clinical application of lncRNA as tools for HCC diagnosis and treatment.

Therapeutic targets of cancer drugs: Modulation by melatonin

The biological functions of melatonin range beyond the regulation of the circadian rhythm. With regard to cancer, melatonin's potential to suppress cancer initiation, progression, angiogenesis and metastasis as well as sensitizing malignant cells to conventional chemo- and radiotherapy are among its most interesting effects. The targets at which melatonin initiates its anti-cancer effects are in common with those of a majority of existing anti-cancer agents, giving rise to the notion that this molecule is a pleiotropic agent sharing many features with other antineoplastic drugs in terms of their mechanisms of action. Among these common mechanisms of action are the regulation of several major intracellular pathways including mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and protein kinase B (AKT/PKB) signaling. The important mediators affected by melatonin include cyclins, nuclear factor-κB (NF-κB), heat shock proteins (HSPs) and c-Myc, all of which can serve as potential targets for cancer drugs. Melatonin also exerts some of its anti-cancer effects via inducing epigenetic modifications, DNA damage and mitochondrial disruption in malignant cells. The regulation of these mediators by melatonin mitigates tumor growth and invasiveness via modulating their downstream responsive genes, housekeeping enzymes, telomerase reverse transcriptase, apoptotic gene expression, angiogenic factors and structural proteins involved in metastasis. Increasing our knowledge on how melatonin affects its target sites will help find ways of exploiting the beneficial effects of this ubiquitously-acting molecule in cancer therapy. Acknowledging this, here we reviewed the most studied target pathways attributed to the anti-cancer effects of melatonin, highlighting their therapeutic potential.

lncRNA involvement in cancer stem cell function and epithelial-mesenchymal transitions

Epithelial to mesenchymal transition (EMT) is a cellular process in which cells composing epithelial tissue lose requirements for physical contact with neighboring cells and acquire mesenchymal characteristics consisting of increased migratory and invasive behaviors. EMT is a fundamental process that is required for initial and later events during embryogenesis. Cancer stem cells (CSCs) possess multipotency sufficient for their differentiation into bulk tumor cells and also have the capacity to undergo EMT. When CSCs initiate EMT programs the resulting cancerous mesenchymal cells become invasive and this migratory behavior also poises them for metastatic activity. Long noncoding RNAs (lncRNAs) are functional RNA molecules that do not encode proteins, yet regulate the expression of protein-coding genes through recruitment or sequestration of gene-regulatory proteins and microRNAs. lncRNA exhibit tissue-specific patterns of gene expression during development and specific sets of lncRNAs are also involved in various cancer types. This review considers the interplay between lncRNAs and the biogenesis of CSCs. We also review function of lncRNAs in EMT in CSCs. In addition, we discuss the utility of lncRNAs as biomarkers of cancer progression, and their potential use as therapeutic targets for treatment of cancer.

Exercise-mediated downregulation of MALAT1 expression and implications in primary and secondary cancer prevention

Long non-coding RNAs (lncRNAs) play critical roles in various biological functions and disease processes including cancer. The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was initially identified as a lncRNA with elevated expression in primary human non-small cell lung tumors with high propensity to metastasize, and subsequently shown to be highly expressed in numerous other human cancers including breast, ovarian, prostate, cervical, endometrial, gastric, pancreatic, sarcoma, colorectal, bladder, brain, multiple myeloma, and lymphoma. MALAT1 is deeply involved in several physiological processes, including alternative splicing, epigenetic modification of gene expression, cellular senescence, healthy aging, and redox homeostasis. The aim of this work was to investigate the modulation exerted by a single bout of endurance exercise on the level of MALAT1 expression in peripheral blood mononuclear cells (PBMCs) from healthy male donors displaying different training status and redox homeostasis features. Our findings show that MALAT1 is downregulated after acute endurance exercise in subjects whose fitness level guarantee a high expression of SOD1 and SOD2 antioxidant genes and low levels of endogenous oxidative damage. In vitro protocols in Jurkat lymphoblastoid cells exposed to pro-oxidant environment confirmed the link between MALAT1 expression and antioxidant gene modulation, documenting p53 phosphorylation and its recruitment to MALAT1 promoter. Remarkably, analyses of Microarray-Based Gene Expression Profiling revealed high MALAT1 expression in leukemia patients in comparison to healthy control and a significant negative correlation between MALAT1 and SOD1 expression. Collectively our results highlight the beneficial effect of a physically active lifestyle in counteracting aberrant cancer-related gene expression programs by improving the redox buffering capacity.

Comprehensive Analysis of Aberrantly Expressed Competitive Endogenous RNA Network and Identification of Prognostic Biomarkers in Pheochromocytoma and Paraganglioma

Background

Long non-coding RNA (lncRNA) functions as a competitive endogenous RNA (ceRNA) and plays an important role in the biological processes underlying tumorigenesis. However, studies describing the function of lncRNA in pheochromocytoma and paraganglioma (PCPG) remain largely unknown. Our study aims to construct a regulatory ceRNA network and explore prognostic biomarkers for PCPG through a comprehensive analysis.

Methods

PCPG data from The Cancer Genome Atlas (TCGA) were utilized to obtain differentially expressed lncRNAs (DElncRNAs), microRNAs (DEmiRNAs), and mRNAs (DEmRNAs). Kaplan–Meier analysis was used to detect prognostic biomarkers and Cytoscape was utilized to construct a regulatory network of ceRNA. Potential lncRNA–miRNA–mRNA axes were inferred by correlation analysis. GO and KEGG pathways were constructed using “clusterProfiler” and “DOSE” R-packages. Immunohistochemistry (IHC) staining was performed to validate differential protein expression levels of genes in the axes. Finally, the GSE19422 dataset and Pan-Cancer data were applied to validate the expression pattern and survival status of mRNAs, respectively.

Results

A total of 334 DElncRNAs, 116 DEmiRNAs, and 3496 DEmRNAs were identified and mainly enriched in hormone secretion, metabolism signaling, metastatic and proliferative pathways. Among these differentially expressed genes, 16 mRNAs, six lncRNAs, and two miRNAs were associated with overall survival of patients with PCPG and sequentially enrolled in the ceRNA network. Two lncRNA–miRNA–mRNA regulatory axes were predicted: AP001486.2/hsa-miR-195-5p/RCAN3 and AP006333.2/hsa-miR-34a-5p/PTPRJ. The GSE19422 dataset and IHC analysis validated that mRNA and protein levels of RCAN3 and PTPRJ were upregulated in PCPG tissues compared with adjacent adrenal gland medulla tissues. Pan-Cancer data showed that the upregulated expression of RCAN3 and PTPRJ was associated with favorable overall survival and disease-free survival.

Conclusion

A regulatory lncRNA–miRNA–mRNA ceRNA network was successfully constructed and 24 prognostic biomarkers were identified for PCPG patients. These findings may contribute toward a better understanding of the biological mechanism of tumorigenesis and enable further evaluation of the prognosis of patients with PCPG.

Non-Coding RNAs: Uncharted Mediators of Thyroid Cancer Pathogenesis

Thyroid cancer is the most prevalent malignancy of the endocrine system and the ninth most common cancer globally. Despite the advances in the management of thyroid cancer, there are critical issues with the diagnosis and treatment of thyroid cancer that result in the poor overall survival of undifferentiated and metastatic thyroid cancer patients. Recent studies have revealed the role of different non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) that are dysregulated during thyroid cancer development or the acquisition of resistance to therapeutics, and may play key roles in treatment failure and poor prognosis of the thyroid cancer patients. Here, we systematically review the emerging roles and molecular mechanisms of ncRNAs that regulate thyroid tumorigenesis and drug response. We then propose the potential clinical implications of ncRNAs as novel diagnostic and prognostic biomarkers for thyroid cancer.

LncRNA DGCR5 plays a tumor-suppressive role in glioma via the miR-21/Smad7 and miR-23a/PTEN axes

Glioma is one of the most commonly diagnosed brain malignancies with a high cancer-related death rate in humans. The prognosis of glioma patients is still unsatisfactory. In the present study, we attempted to identify lncRNAs and miRNAs that might be related to NF-κB-mediated epithelial-mesenchymal transition in glioma cells based on online microarray expression profiles, and investigate the specific effects of lncRNA-miRNA-mRNA axes on glioma cell phenotypes. Herein, we identified lncRNA DGCR5 as a downregulated lncRNA in glioma that was negatively regulated by NF-κB1 in an NF-κB1 RE-dependent manner. LncRNA DGCR5 overexpression significantly inhibited the capacity of glioma cells to proliferate, migrate, and invade, whereas promoted the apoptosis of glioma cells. Moreover, lncRNA DGCR5 overexpression upregulated the epithelial marker E-cadherin while downregulating the mesenchymal marker VIM, as well as Snai2 and TWIST. Regarding the underlying molecular mechanisms, lncRNA DGCR5 could inhibit miR-21 and miR-23a expression, and miR-21 or miR-23a overexpression significantly reversed the tumor-suppressive effects of lncRNA DGCR5 overexpression. LncRNA DGCR5 exerted its tumor-suppressive effects through the DGCR5/miR-21/Smad7 and DGCR5/miR-23a/PTEN axes. In conclusion, lncRNA DGCR5 suppresses the capacity of glioma cells to migrate and invade via miR-21/Smad7, whereas it inhibits the proliferation and enhances the apoptosis of glioma cells through miR-23a/PTEN.

Small nucleolar RNA host gene 22 (SNHG22) promotes the progression of esophageal squamous cell carcinoma by miR-429/SESN3 axis

Background

It has been observed that lncRNAs have been taking part in many cancer progressions, including non-small cell lung cancer and gastric cancer. Meanwhile, lncRNA small nucleolar RNA host gene 22 (SNHG22) has been studied, taking part in the progression of ovarian epithelial carcinoma. However, we know little about the function of SNHG22 in esophageal squamous cell carcinoma (ESCC).

Methods

In this study, we will explore the inner mechanism of SNHG22 in ESCC. Quantitative real-time PCR (qRT-PCR) assay was implemented in ESCC cells for detecting the expression of lncRNA, SNHG22, and miR-429. Also, functional experiments, including CCK8 and colony formation assay, were implemented to assess the growth of ESCC cells. Meanwhile, flow cytometry analysis was conducted to test the apoptosis of ESCC cells. The immunofluorescence (IF) assay and western blot were conducted to verify the autophagy of ESCC cells.

Results

Inhibition of SNHG22 was found that can inhibit the progression and promotes autophagy and apoptosis of ESCC cells. Meanwhile, as subcellular fraction assay and FISH assay found that SNHG22 mainly in the cytoplasm, miR-429 was found can bind to SNHG22 and SESN3 by RIP assay and luciferase reporter assay. SESN3 was found it can play the oncogene in ESCC cells.

Conclusions

SNHG22 promotes the progression of ESCC by the miR-429/SESN3 axis.

RNA-Binding Proteins as Regulators of Migration, Invasion and Metastasis in Oral Squamous Cell Carcinoma

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.

RHPN1-AS1 Drives the Progression of Hepatocellular Carcinoma via Regulating miR-596/IGF2BP2 Axis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most deadly cancer types worldwide, and its incidence is high in China. Multiple long non-coding RNAs (lncRNAs) have been recently identified as crucial oncogenic factors or tumor suppressors. In this study, we explored the effects of LncRNA RHPN1 antisense RNA 1 (RHPN1-AS1) on the progression of HCC.

METHODS

Expression levels of RHPN1-AS1 and miR-596 in HCC samples were measured by qRT-PCR. The association between pathological indexes and the expression level of RHPN1-AS1 was also analyzed. Human HCC cell lines Huh7 and SMMC-7721 were used as cell models. CCK-8 and colony formation assays were performed to assess the effect of RHPN1-AS1 on HCC cell line proliferation. The flow cytometer instrument was used to study the effect of RHPN1-AS1 on apoptosis of HCC cells. The transwell assay was conducted to detect the effect of RHPN1-AS1 on migration and invasion. Furthermore, luciferase reporter assay was used to confirm targeting of miR-596 by RHPN1-AS1. Additionally, the regulatory function of RHPN1-AS1 on insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) was detected by western blot.

RESULTS

The expression level of RHPN1-AS1 in HCC samples was observed to significantly increase compared with normal tissues and its high expression was correlated with unfavorable pathological indexes. Highly expressed RHPN1-AS1 was associated with shorter overall survival time. RHPN1-AS1 overexpression remarkably accelerated proliferation and metastasis of HCC cells, while reduced apoptosis. Accordingly, RHPN1-AS1 knockdown suppressed the malignant phenotypes of HCC cells. RHPN1-AS1 overexpression significantly reduced miR-596 expression by sponging it, but enhanced IGF2BP2 expression.

CONCLUSION

RHPN1-AS1 acts as a sponge of tumor suppressor miR-596 in HCC that can indirectly enhance the IGF2BP2 expression and function as an oncogenic lncRNA.

The roles of long noncoding RNAs in breast cancer metastasis

Breast cancer is the most significant threat to female health. Breast cancer metastasis is the major cause of mortality in breast cancer patients. To fully unravel the molecular mechanisms that underlie the breast cancer cell metastasis is critical for developing strategies to improve survival and prognosis in breast cancer patients. Recent studies have revealed that the long noncoding RNAs (lncRNAs) are involved in breast cancer metastasis through a variety of molecule mechanisms, though the precise functional details of these lncRNAs are yet to be clarified. In the present review, we focus on the functions of lncRNAs in breast cancer invasion and metastasis, with particular emphasis on the functional properties, the regulatory factors, the therapeutic promise, as well as the future challenges in studying these lncRNA.

A Long Intergenic Non-coding RNA, LINC01426, Promotes Cancer Progression via AZGP1 and Predicts Poor Prognosis in Patients with LUAD

Various long non-coding RNAs (lncRNAs) are closely associated with lung adenocarcinoma (LUAD), playing oncogenic or anti-oncogenic roles in tumorigenesis and progression. Herein, we report a novel lncRNA-long intergenic non-protein coding RNA 1426 (LINC01426)-that has not yet been characterized in LUAD. We note that LINC01426 expression was markedly upregulated in LUAD tissues, and that functional assays verified that LINC01426 knockdown markedly inhibited cell proliferation, migration, and invasion in vitro. Xenografts derived from A549 cells knocked down of LINC01426 had evidently lower tumor weights and smaller tumor volumes. Our study also found that LINC01426 bound to hsa-miR-30b-3p as a competitive endogenous RNA in LUAD. Moreover, LINC01426 affected LUAD wound healing by interacting and combining with AZGP1, and LINC01426 expression was significantly associated with tumor-node-metastasis (TNM) staging and prognosis in patients with LUAD. To summarize, our study elucidates the oncogenic roles of LINC01426 in LUAD tumorigenesis and progression. We think that LINC01426 can serve as a potential diagnostic biomarker and therapeutic target in patients with LUAD.

Prognostic value of long non-coding RNAs in triple negative breast cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive and lethal subtype of breast cancer. Accumulating evidence showed long non-coding RNAs (lncRNAs) are abnormally expressed in TNBC and could be valuable prognostic tools for TNBC patients. This study aims to research the prognostic value of lncRNAs in TNBC, using the meta-analysis method.

METHODS

We performed a detailed literature search on Pubmed, Scopus, and Web of Science for studies on the prognostic value of lncRNAs in TNBC. The meta-analysis method was used to determine the relationship between lncRNAs expression and survival of TNBC patients.

RESULTS

A total of 2803 TNBC patients and 24 lncRNAs from 27 different articles were included in the present study. Subgroup analysis demonstrated that overexpression of lncRNAs in a group that is upregulated in TBNC showed a significant association with poor overall survival (HR = 1.86, 95%CI = 1.45-2.27, I = 41.9%) and disease-free survival (HR = 1.85, 95%CI = 1.37-2.33, I = 0%). Conversely, overexpression of lncRNAs in a downregulation group was markedly related to good overall survival (HR = 0.60, 95%CI = 0.43-0.77, I = 28.6%). Moreover, expression of lncRNA SNHG12, MALAT1, HOTAIR, HIF1A-AS2, HULC, LINC00096, ZEB2-AS1, LUCAT1, and LINC000173 showed a marked correlation with positive lymph node metastasis (LNM), while lncRNA MIR503HG, GAS5, TCONS_l2_00002973 showed the opposite effect. High expression level of MALAT1, HIF1A-AS2, HULC, LINC00096, ADPGK-AS1, ZEB2-AS1, LUCAT1 were positively correlated with distant metastasis (DM), while lncRNA MIR503HG showed the opposite effect. In addition, the mechanisms of lncRNAs in TNBC were summarized.

CONCLUSIONS

This meta-analysis demonstrated that abnormally expressed lncRNA were significantly associated with the survival of TNBC patients and may serve as biomarkers and therapeutic targets for TNBC prognosis.

Silencing of LncRNA C1RL-AS1 Suppresses the Malignant Phenotype in Gastric Cancer Cells via the AKT/β-Catenin/c-Myc Pathway

Purpose: Numerous studies have shown that lncRNAs play vital roles in the development and progression of cancer. However, investigations of lncRNAs in gastric cancer are limited and need to be further pursued. Materials and Methods: According to RNA-seq results of gastric cancer (GC) tissues, we identified a novel lncRNA, C1RL-AS1. qRT-PCR was used to detect the expression level of C1RL-AS1 in paired GC and normal tissues. Nuclear/cytoplasmic fractionation was applied to evaluate the distribution of C1RL-AS1 in GC cells. For functional evaluation, CCK-8, colony formation, transwell, and apoptosis assays were used to determine the oncogenic role of C1RL-AS1. Results: C1RL-AS1 was upregulated in GC tissues, and high expression levels of C1RL-AS1 were associated with poor prognosis. Further in vitro functional assays revealed that silencing C1RL-AS1 attenuated the proliferation rate and migration ability and enhanced the apoptotic rate and the senescence of GC cells. The subsequent underlying mechanistic investigation revealed that Wnt/β-catenin was involved in C1RL-AS1-mediated signaling. Rescue experiments suggested that C1RL-AS1 probably promoted the malignant phenotype via the AKT/β-catenin pathway by downregulating c-Myc. Conclusions: C1RL-AS1 probably exerts its biological function by mediating the AKT/β-catenin/c-Myc pathway, indicating a novel therapeutic target in GC.

Inhibition of lncRNA TMPO‑AS1 suppresses proliferation, migration and invasion of colorectal cancer cells by targeting miR‑143‑3p

Long non-coding RNAs (lncRNAs) are widely studied in cancer pathogenesis. Accumulating evidence has demonstrated that lncRNAs are involved in the cellular progression of colorectal cancer (CRC). However, the regulatory mechanism of lncRNA TMPO-antisense (AS)1 in CRC has not been fully elucidated. The present study aimed to elucidate the role and regulatory mechanisms of lncRNA TMPO-AS1 in CRC. In the present study, the expression levels of TMPO-AS1 and microRNA-143-3p (miR-143-3p) were detected using reverse transcription-quantitative PCR assay. The relative protein expression levels were measured via western blot analysis. MTT and Transwell assays were used to determine cell proliferation, migration and invasion, while a luciferase reporter assay was performed to assess the relationship between TMPO-AS1 and miR-143-3p. In addition, a tumor animal model was used to investigate the effect of TMPO-AS1 on tumor growth in CRC in vivo. TMPO-AS1 expression was increased and miR-143-3p expression was decreased in CRC cells. TMPO-AS1 knockdown and miR-143-3p overexpression significantly inhibited cell proliferation, migration and invasion of CRC cells. Luciferase reporter assay results demonstrated that miR-143-3p was a direct target of TMPO-AS1. Inhibition of miR-143-3p could alleviate the suppressive effects of TMPO-AS1 deletion on cell proliferation, migration and invasion of CRC cells. Furthermore, TMPO-AS1 deletion could inhibit tumor growth in CRC in vivo. It was concluded that TMPO-AS1 regulated cell proliferation, migration and invasion of CRC cells by targeting miR-143-3p. These findings provided a new regulatory network and therapeutic target for the treatment of CRC.

LncR2metasta: a manually curated database for experimentally supported lncRNAs during various cancer metastatic events

Mounting evidence has shown the involvement of long non-coding RNAs (lncRNAs) during various cancer metastatic events (abbreviated as CMEs, e.g. cancer cell invasion, intravasation, extravasation, proliferation, etc.) that may cooperatively facilitate malignant tumor spread and cause massive patient deaths. The study of lncRNA-CME associations might help understand lncRNA functions in metastasis and present reliable biomarkers for early dissemination detection and optimized treatment. Therefore, we developed a database named 'lncR2metasta' by manually compiling experimentally supported lncRNAs during various CMEs from existing studies. LncR2metasta documents 1238 associations between 304 lncRNAs and 39 CMEs across 54 human cancer subtypes. Each entry of lncR2metasta contains detailed information on a lncRNA-CME association, including lncRNA symbol, a specific CME, brief description of the association, lncRNA category, lncRNA Entrez or Ensembl ID, lncRNA genomic location and strand, lncRNA experiment, lncRNA expression pattern, detection method, target gene (or pathway) of lncRNA, lncRNA regulatory role on a CME, cancer name and the literature reference. An easy-to-use web interface was deployed in lncR2metasta for its users to easily browse, search and download as well as to submit novel lncRNA-CME associations. LncR2metasta will be a useful resource in cancer research community. It is freely available at http://lncR2metasta.wchoda.com.

Serum LncRNA-ATB and FAM83H-AS1 as diagnostic/prognostic non-invasive biomarkers for breast cancer

AIMS

Circulating long non-coding RNAs (lncRNAs) have proven to be useful non-invasive tools for diagnosis of various cancers. FAM83H antisense RNA 1 (FAM83H-AS1) and lncRNA activated by TGF β (lncRNA-ATB) are two lncRNAs that have been shown to play an important role in different cancer types including breast cancer. The primary aim of our study was to investigate the potential role of serum FAM83H-AS1 and lncRNA-ATB as diagnostic/prognostic markers for breast cancer patients.

MAIN METHODS

Serum expression levels of FAM83H-AS1 and lncRNA-ATB were analyzed in 90 breast cancer patients and 30 age- and sex-matched healthy controls using RT-qPCR.

KEY FINDINGS

We found that FAM83H-AS1 and lncRNA-ATB were significantly overexpressed in sera of breast cancer patients compared to controls (p = 0.000 for both). Analysis of receiver operating characteristic curve demonstrated that lncRNA-ATB had a higher area under curve (AUC) value than the conventional tumor marker cancer antigen 15-3 (CA15-3) (AUC: 0.844, p = 0.000 versus 0.738, p = 0.002) for early diagnosis of breast cancer in patients with stage I-II. On the other hand, FAM83H-AS1 showed a significant correlation with tumor-node metastasis (TNM) stages, large tumor size and lymph node metastasis, suggesting a prognostic rather than diagnostic value.

SIGNIFICANCE

This is the first study to demonstrate that serum lncRNA-ATB could be used as a non-invasive diagnostic marker for early stages of breast cancer. Furthermore, serum FAM83H-AS1 has a potential ability for monitoring of progression and staging of breast cancer.

Exosomal lncRNA PCAT-1 promotes Kras-associated chemoresistance via immunosuppressive miR-182/miR-217 signaling and p27/CDK6 regulation

Immunosuppressive chemoresistance is a major burden in lung cancer. Recent data reveal that long noncoding RNAs (lncRNAs) present in the lung tumor microenvironment are implicated in chemoresistant-related immune deregulation, and metastasis but their exact pathogenic role is still unknown. In this study, we investigate the role of lncRNA PCAT-1 in chemoresistant immunosuppression and its involvement in tumor stroma remodeling. Findings reveal PCAT-1 to regulate Kras-related lung chemoresistance through increased expression of the immunosuppressive micrornas miR-182/miR217 in lung tissues, thus promoting a pre-metastatic niche formation and a subsequent increase in lung metastatic burden. Elevated expression of PCAT-1 negative regulates p27/CDK6 expression by inducing G₀/G₁ cell cycle arrest through AMPK augmentation, contributing to a tumor-promoting status. Furthermore, PCAT-1 triggered fibroblast differentiation followed by CAF/myofibroblast secretion in TME triggering a CD133/SOX2-related stem cell phenotype. Subsequent PCAT-1 knockdown impaired CAF-mediated stromal activation, and reversed chemoresistance and tumor growth in vivo. Overall, these findings demonstrate the versatile roles of PCAT-1 in sustaining lung immunosuppressive neoplasia through tumor microenvironment remodeling and provide new opportunities for effective metastasis inhibition, especially in chemoresistant tumors.

Silencing of long non-coding RNA SOX21-AS1 inhibits lung adenocarcinoma invasion and migration by impairing TSPAN8 via transcription factor GATA6

Here, we revealed the novel role of long non-coding RNAs (lncRNAs) SOX21 antisense RNA 1 (SOX21-AS1)/TSPAN8/GATA6 in progression of lung adenocarcinoma. SOX21-AS1 expression was quantified in lung adenocarcinoma tissues and cells by RT-qPCR. Then, gain- and loss-of-function experiments were conducted in lung adenocarcinoma cells. Expression of GATA6, TSPAN8 and extracellular signal-regulated kinase (ERK) signaling pathway-related genes was determined in lung adenocarcinoma cells by western blot analysis. The interaction and relationship among SOX21-AS1, GATA6 and TSPAN8 were predicted and verified respectively by RNA pull down, RIP, ChIP, and dual-luciferase reporter assays. Next, lung adenocarcinoma cell proliferation, colony formation, invasion and migration were assessed by 5-ethynyl-2'-deoxyuridine staining, colony formation assay and Transwell assay. Xenograft tumors were established in nude mice and the tumor growth was observed and recorded. SOX21-AS1 was observed to be highly expressed in lung adenocarcinoma tissues. The overexpression of SOX21-AS1, GATA6 or TSPAN8 obviously enhanced cell biological functions in lung adenocarcinoma. Meanwhile, SOX21-AS1 interacted with GATA6 which bound to TSPAN8 promoter and promoted TSPAN8 expression, which further enhanced cell colony formation, proliferation and invasion, and also activated ERK signaling pathway. Silencing of SOX21-AS1 and inhibiting its binding to GATA6 downregulate TSPAN8 and thereby exert anti-oncogenic effects in lung adenocarcinoma.

MicroRNA‑199a‑5p suppresses cell proliferation, migration and invasion by targeting ITGA3 in colorectal cancer

As a member of the integrin family, integrin α3β1 (ITGA3) has been linked to intercellular communication and serves an important role in the signaling among cells and the extracellular matrix. MicroRNA (miR)-199a-5p has been demonstrated to be related to the pathogenesis and progression of multiple malignant diseases. However, the biological functions of miR-199a-5p and ITGA3 in colorectal cancer (CRC) have rarely been reported. The aim of the present study was to explore the roles of miR-199a-5p and ITGA3 in CRC. Immunohistochemistry staining and western blotting were applied to detect the protein expression of ITGA3 in CRC tissues and cells. Reverse transcription-quantitative PCR was performed to investigate the expression of miR-199a-5p and ITGA3 mRNA. HCT-116 cells were transfected with miR-199a-5p mimics, mimics control, short hairpin RNA targeting ITGA3, or pcDNA-ITGA3 for the functional experiments. Dual luciferase reporter assay was applied to confirm whether miR-199a-5p targeted the 3′ untranslated region (3′UTR) of ITGA3. The MTT, Transwell and wound healing assays were used to evaluate the proliferation, invasion and migration of CRC cells. Immunofluorescence assay was used to monitor the epithelial-mesenchymal transition (EMT) biomarker expression. The results demonstrated downregulation of miR-199a-5p and upregulation of ITGA3 in CRC tissues and cell lines. miR-199a-5p mimics and knockdown of ITGA3 suppressed the proliferation, invasion and migration of CRC cells. Bioinformatics analysis and luciferase reporter assay indicated that miR-199a-5p targeted the 3′UTR of the ITGA3 transcript, and overexpression of ITGA3 reversed the tumor-suppressive effects of miR-199a-5p elevation. In addition, the immunofluorescence assay suggested that miR-199a-5p mimics suppressed the EMT of CRC cells, whereas the overexpression of ITGA3 restored this effect. In conclusion, miR-199a-5p may act as a tumor suppressor by targeting and negatively regulating ITGA3 in CRC.

Long Intergenic Non-Protein Coding RNA 1089 Suppresses Cell Proliferation and Metastasis in Gastric Cancer by Regulating miRNA-27a-3p/Epithelial-Mesenchymal Transition (EMT) Axis

Aim

To explore the expression and biological function of long intergenic non-protein coding RNA 1089 (LINC01089) in gastric cancer (GC) progression and its underlying mechanism.

Methods

LINC01089 and microRNA-27a-3p (miR-27a-3p) expressions were detected with the quantitative real-time polymerase chain reaction (RT-qPCR). Cell proliferation, migration and invasion were evaluated by Cell Counting Kit-8 (CCK-8) and Transwell assay. Epithelial-mesenchymal transition (EMT)-related proteins were also measured by Western blot. The relationship between LINC01089 and miR-27a-3p was revealed by a bioinformatics analysis and dual-luciferase reporter assay.

Results

LINC01089 was significantly down-regulated in GC tissues, as well as GC cell lines. GC patients with lower LINC01089 expression were more likely to have poor outcomes. Overexpression of LINC01089 significantly suppressed GC cells growth, migration and invasion and forbade the EMT process. LINC01089 was directly targeted at miR-27a-3p. The transfection of miR-27a-3p mimics reversed the inhibitory effects on proliferative and metastatic abilities of GC cells with LINC01089 overexpression.

Conclusion

LINC01089 inhibits cell proliferation and metastasis in GC by targeting miR-27a-3p/EMT axis, which should be considered as a promising therapeutic target.

Hypoxia-induced alternative splicing: the 11th Hallmark of Cancer

Hypoxia-induced alternative splicing is a potent driving force in tumour pathogenesis and progression. In this review, we update currents concepts of hypoxia-induced alternative splicing and how it influences tumour biology. Following brief descriptions of tumour-associated hypoxia and the pre-mRNA splicing process, we review the many ways hypoxia regulates alternative splicing and how hypoxia-induced alternative splicing impacts each individual hallmark of cancer. Hypoxia-induced alternative splicing integrates chemical and cellular tumour microenvironments, underpins continuous adaptation of the tumour cellular microenvironment responsible for metastatic progression and plays clear roles in oncogene activation and autonomous tumour growth, tumor suppressor inactivation, tumour cell immortalization, angiogenesis, tumour cell evasion of programmed cell death and the anti-tumour immune response, a tumour-promoting inflammatory response, adaptive metabolic re-programming, epithelial to mesenchymal transition, invasion and genetic instability, all of which combine to promote metastatic disease. The impressive number of hypoxia-induced alternative spliced protein isoforms that characterize tumour progression, classifies hypoxia-induced alternative splicing as the 11th hallmark of cancer, and offers a fertile source of potential diagnostic/prognostic markers and therapeutic targets.

Novel Long Non-coding RNA lncAMPC Promotes Metastasis and Immunosuppression in Prostate Cancer by Stimulating LIF/LIFR Expression

Long non-coding RNAs (lncRNAs) participate in the development and progression of prostate cancer (PCa). We aimd to identify a novel lncRNA, named lncRNA activated in metastatic PCa (lncAMPC), and investigate its mechanisms and clinical significance in PCa. First, the biological capacity of lncAMPC in PCa was demonstrated both in vitro and in vivo. The lncAMPC was overexpressed in tumor tissue and urine of metastatic PCa patients and promoted PCa tumorigenesis and metastasis. Then, a mechanism study was conducted to determine how the lncAMPC-activated pathway contributed to PCa metastasis and immunosuppression. In the cytoplasm, lncAMPC upregulated LIF expression by sponging miR-637 and inhibiting its activity. In the nucleus, lncAMPC enhanced LIFR transcription by decoying histone H1.2 away from the upstream sequence of the LIFR gene. The lncAMPC-activated LIF/LIFR expressions stimulated the Jak1-STAT3 pathway to simultaneously maintain programmed death-ligand 1 (PD-L1) protein stability and promote metastasis-associated gene expression. Finally, the prognostic value of the expression of lncAMPC and its downstream genes in PCa patients was evaluated. High LIF/LIFR levels indicated shorter biochemical recurrence-free survival among patients who underwent radical prostatectomy. Therefore, the lncAMPC/LIF/LIFR axis plays a critical role in PCa metastasis and immunosuppression and may serve as a prognostic biomarker and potential therapeutic target.

Astragaloside-IV regulates endoplasmic reticulum stress-mediated neuronal apoptosis in a murine model of Parkinson's disease via the lincRNA-p21/CHOP pathway

OBJECTIVES

Astragaloside-IV (AS-IV) protects the nerve cells of Parkinson's disease (PD) from damage. Long non-coding RNA (lincRNA) has been found to be important for many diseases. Lincnra-p21 is abnormally expressed in PD. The purpose of this study was to investigate whether Astragaloside-IV (AS-IV) affects endoplasmic reticulum stress (ERS)-induced neuronal apoptosis in PD, and its possible mechanisms.

METHODS

The PD mouse model was established via injecting 1-methyl-4-phenyl-1, 2, 3, 6- tetrahydropyridine (MPTP) and the PD cell model was established via inducing the MN9D cell line with 1-methyl-4-pehnyl-pyridine (MPP⁺). The behavioral testing of PD model mice was tested after AS-IV treatment and PD-related lincRNAs expression were detected by qRT-PCR. After treatment of PD model cells with AS-IV, lincRNA-p21 expression was detected by qRT-PCR, and cell viability and apoptosis were detected by MTT assay and flow cytometry, respectively. The binding of lincRNA-p21 to C/EBP-homologous (CHOP) protein was investigated by RNA immunoprecipitation and RNA pull-down, and the effect of lincRNA-p21 on the ubiquitination of CHOP protein was examined by ubiquitination assay. The role of lincRNA-p21 in PD model was studied by cell transfection.

RESULTS

In PD mice, AS-IV can improve the behavior of mice and significantly inhibit expression of lincRNA-p21. Similarly, AS-IV can obviously restrain the expression of lincRNA-p21 in PD cells, and obviously elevated cell viability and restrained apoptosis. LincRNA-p21 is able to bind to CHOP protein. Further studies showed that restraint of lincRNA-p21 expression can facilitate ubiquitination of CHOP and accelerate its protein degradation. In AS-IV-treated PD model cells, overexpression of lincRNA-p21 lessened cell viability and facilitated apoptosis, whereas low expression of CHOP reversed this result.

CONCLUSION

In this study, we found that AS-IV can lessen the expression of CHOP protein by restraining the expression of lincRNA-p21 in the PD model, thereby inhibiting neuronal apoptosis.