Up-regulation of long intergenic noncoding RNA 01296 in ovarian cancer impacts invasion, apoptosis and cell cycle distribution via regulating EMT

The Role of EMT-Related lncRNAs in Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest cancers worldwide; late diagnosis and drug resistance are two major factors often responsible for high morbidity and treatment failure. Epithelial-to-mesenchymal transition (EMT) is a dynamic process that has been closely linked with cancer. Long non-coding RNAs (lncRNAs) have been also associated with several cancer-related mechanisms, including EMT. We conducted a literature search in the PubMed database in order to sum up and discuss the role of lncRNAs in regulating OC-related EMT and their underlying mechanisms. Seventy (70) original research articles were identified, as of 23 April 2023. Our review concluded that the dysregulation of lncRNAs is highly associated with EMT-mediated OC progression. A comprehensive understanding of lncRNAs' mechanisms in OC will help in identifying novel and sensitive biomarkers and therapeutic targets for this malignancy.

The ceRNA network regulates epithelial-mesenchymal transition in colorectal cancer

Epithelial-mesenchymal transition (EMT) is a biological process that transforms epithelial cells into a mesenchymal phenotype, conferring cell migration and invasion capabilities. EMT is involved in the progression and metastasis of colorectal cancer (CRC). Recently, emerging evidence has shown dysregulation of non-coding RNA (ncRNA) was linked to EMT. ncRNAs, including long non-coding RNA (lncRNA), regulate the transcription of downstream target genes (mRNA) through interaction with microRNAs (miRNAs); these are termed competitive endogenous RNA (ceRNA) networks. CeRNA dysregulation-induced EMT, which is linked to the progression and prognosis of CRC, has attracted wide attention. However, understanding the role of the regulation of the ceRNA network in the EMT of CRC remains limited. We discuss the molecular functions of lncRNA, the ceRNA networks related to miRNAs and mRNAs in EMT, as well as EMT transcription factors, such as the zinc finger E-box binding homeobox 1/2 (ZEB1/2), SNAIL, SLUG, and TWIST1/2. In addition, miRNAs and lncRNAs that directly target genes, thereby initiating different signaling pathways to promote EMT in CRC, were summarized. Clarifying the role of these molecules in EMT is critical for understanding molecular mechanisms and exploring the potential therapeutic targets of CRC.

Long non-coding RNA RP5-821D11.7 promotes proliferation, migration, and epithelial-mesenchymal transition in glioma and glioma stem-like cells

Long noncoding RNA (lncRNA) has been recently revealed as a main regulatory molecule, which implicates many cellular functions. Studies showed that lncRNA abnormally expressed and involved in the progression and tumorigenesis of glioma. Present study identified a novel lncRNA associated with glioma, glioma stem-like cells (GSCs), and then revealed their potential functions. During the screening of lncRNAs, we investigated overexpression of lncRNA RP5-821D11.7 (lncRNA-RP5) in GSCs compared to glioma cells. Lentivirus-mediated shRNA for lncRNA-RP5 was constructed and transfected into glioma cells. Transfected stable glioma cells were transplanted into nude mice and tumor growth was observed. Knockdown of lncRNA-RP5 significantly inhibits proliferation, colony formation, migration and reduces epithelial-mesenchymal transition (EMT) by activating the Wnt/β-catenin pathway. Additionally, the results showed that lncRNA RP5 knockdown enhances cell apoptosis through endoplasmic reticulum stress. Therefore, this study may provide a better understanding about lncRNA-RP5 which revealed that it might be a potential therapeutic target in case of glioma progression and recurrence.

Downregulation of LINC01296 suppresses non-small-cell lung cancer via targeting miR-143-3p/ATG2B

The 5-year survival rate of lung cancer is one of the lowest among various malignant tumors. Long noncoding RNAs (lncRNAs), noncoding RNAs longer than 200 nucleotides, can function either as tumor suppressors or as oncogenes. The aim of this study is to investigate the function of lncRNA LINC01296 and its molecular mechanism in non-small-cell lung cancer (NSCLC). According to the Gene Expression Omnibus database, 10 differentially expressed lncRNAs in NSCLC cells and patient tissues are upregulated. LINC01296 is the one with the most significant overexpression. Knockdown of LINC01296 inhibits the growth and migration, arrests the cell cycle, and promotes the apoptosis of NSCLC cells. Knocking down LINC01296 in vivo suppresses tumor growth and metastasis. LINC01296 also acts as the sponge of miR-143-3p. Lowering the expression of LINC01296 leads to decreased expression of autophagy-related 2B (ATG2B), a target gene of miR-143-3p. Moreover, downregulation of LINC01296 promotes paclitaxel sensitivity in NSCLC. These results demonstrated that the LINC01296/miR-143-3p/ATG2B axis is crucial in promoting the development of NSCLC and paclitaxel resistance. Our study may provide new ideas for the further research of clinical chemotherapy of NSCLC in the near future.

LINC01296/miR-141-3p/ZEB1-ZEB2 axis promotes tumor metastasis via enhancing epithelial-mesenchymal transition process

Purpose: Tumor metastasis seriously affects the survival of patients. In recent years, some studies confirmed that long non-coding RNA (lncRNA) played an essential role in tumor progression. A few studies reported that LINC01296 acted as an oncogenic regulator of cancer. However, its in-depth specific biological mechanism in tumor metastasis is still unknown.

Methods: Real-time quantitative PCR (qPCR) was performed to detect the expression of LINC01296 and miR-141-3p in NSCLC, CRC tissues and cell lines, and the dual luciferase report was used to evaluate the relationship between LINC01296, miR-141-3p and ZEB1/ZEB2 relationship. Western blot experiments are used to detect changes in protein levels. Transwell and wound healing measures migration and invasion capabilities.

Results: In this study, we used non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) as the research objects, LINC01296 was found to be highly expressed in NSCLC and CRC tissues and positively related to poor prognosis. We also demonstrated LINC01296 regulated NSCLC and CRC invasion and metastasis by modulating epithelial-mesenchymal transition (EMT) by up-regulating ZEB1 and ZEB2. Consequently, LINC01296 acted as a sponge of miR-141-3p, which negatively regulates EMT process.

Conclusions: The report revealed a new mechanism by which LINC01296 regulates the EMT process through miR-141-3p/ZEB1-ZEB2 axis and affects cancer metastasis.

LINC00494 Promotes Ovarian Cancer Development and Progression by Modulating NFκB1 and FBXO32

BACKGROUND

Ovarian cancer represents one of the most frequent gynecological cancers and is significant cause of death for women around the world. Long non-coding RNAs (lncRNAs) are recognized as critical governors of gene expression during carcinogenesis, but their effects on the occurrence and development of ovarian cancer require further investigation. In this report, we characterized LINC00494 as a novel oncogenic lncRNA in ovarian cancer.

METHODS

Bioinformatics analysis predicted potential interactions among LINC00494, NFκB1, and FBXO32 in ovarian cancer, which were tested by dual-luciferase reporter assay, RNA pull-down, RIP, and ChIP assay. Cancer cells were transfected with relevant treated plasmids, followed by scratch and Transwell assays. The treated cells were injected into nude mice to establish a xenograft model for testing effects of LINC00494 and its target gene in vivo.

RESULTS

LINC00494 and NFκB1 were highly expressed whereas FBXO32 had low expression in ovarian cancer cells and tissues. LINC00494 was found to bind NFκB1 and increase its activity, while NFκB1 was enriched at the FBXO32 promoter region, where it acted to reduce FBXO32 transcription. Overexpression of LINC00494 elevated NFκB1 expression and enhanced cell migration, invasion and tumorigenesis, but additional overexpression of FBXO32 interfered with the tumorgenicity of ovarian cancer cells in vitro and in vivo.

CONCLUSION

Our work demonstrated that LINC00494 promoted ovarian cancer progression by modulating FBXO32 via binding with the transcription factor NFκB1. These results provided new insight into the mechanism of ovarian cancer pathogenesis and suggested new therapeutic targets.

A novel long noncoding RNA, LOC440173, promotes the progression of esophageal squamous cell carcinoma by modulating the miR-30d-5p/HDAC9 axis and the epithelial-mesenchymal transition

Countless evidence suggests that long noncoding RNAs (lncRNAs) are involved in human malignant cancers, including esophageal squamous cell carcinoma (ESCC), although their exact function remains unclear. In the present study, we aimed to investigate the roles and molecular mechanisms of the lncRNA LOC440173 in ESCC progression. Microarray analysis and quantitative real-time polymerase chain reaction were conducted to measure the expression levels of LOC440173 and miR-30d-5p. The biological function of this lncRNA was investigated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, clone formation, and transwell assays, as well as flow cytometry and Western blot analysis. The function of LOC440173 was validated in vivo using tumor xenografts. The regulatory network of LOC440173/miR-30d-5p/HDAC9 was established using bioinformatic analysis and verified with dual-luciferase reporter assays, RNA immunoprecipitation assay, and rescue experiments. The expression level of LOC440173 was significantly increased in ESCC tissues and esophageal carcinoma cells. High LOC440173 expression was correlated with histological grade, tumor invasion depth, lymph node metastasis, and TNM stage. Overexpression of LOC440173 promoted esophageal cancer cell proliferation, migration, and invasion, as well as the epithelial-mesenchymal transition (EMT) process in vitro, and facilitated tumor growth in vivo. MicroRNA-30d-5p (miR-30d-5p) was downregulated in ESCC tissues and acted as a direct binding target of LOC440173 during the regulation of HDAC9 expression in esophageal carcinoma cells. In conclusion, LOC440173 exerts a promotive role in ESCC tumorigenesis by targeting the miR-30d-5p/HDAC9 axis and regulating the EMT process. LOC440173 might be a new therapeutic target for the treatment of ESCC.

LINC00265 targets miR-382-5p to regulate SAT1, VAV3 and angiogenesis in osteosarcoma

We explored the mechanism by which LINC00265 regulates angiogenesis of osteosarcoma cells via the miR-382-5p/spermidine/spermine N1-acetyltransferase-1 (SAT1) and miR-382-5p/vav guanine nucleotide exchange factor 3 (VAV3) axis. Cell scratch assay, Transwell assay and tube formation assay were applied to detect cell migration, invasion and tube formation abilities. The effects of LINC00265 targeting miR-382-5p in osteosarcoma in vivo were studied using a tumour-burden assay. A total of 70 genes potentially involved in osteosarcoma angiogenesis were identified, and a Gene Ontology (GO) analysis found that SAT1 and VAV3 were closely related to angiogenesis. Bioinformatics analysis and clinical experiments confirmed that LINC00265, SAT1 and VAV3 were overexpressed in osteosarcoma and related to a poor prognosis, whereas miR-382-5p was downregulated and associated with a poor prognosis. It was confirmed that LINC00265 promoted the proliferation, migration, invasion and angiogenesis of osteosarcoma cells by targeting miR-382-5p to mediate SAT1 and VAV3. Collectively, LINC00265 might promote proliferation, migration, invasion and angiogenesis by targeting miR-382-5p/SAT1 and miR-382-5p/VAV3 in osteosarcoma.

Comprehensive analysis of long non‑coding RNA using an associated competitive endogenous RNA network in Wilms tumor

Wilms tumor (WT) is the most common malignant renal neoplasm in children; however, the underlying molecular mechanisms are not well understood. According to the competing endogenous RNA (ceRNA) theory, long non-coding RNAs (lncRNAs) can regulate the expression of target genes by adsorbing microRNAs (miRNAs/miRs). However, the role of lncRNAs in WT has not been fully elucidated. The aim of the present study was to construct a ceRNA network to identify the potential lncRNAs involved in WT. The expression profiles of lncRNAs, miRNAs and mRNAs in 120 WT and six normal tissues were obtained from the Therapeutically Applicable Research to Generate Effective Treatments database. A total of 442 lncRNAs, 214 miRNAs and 4,912 mRNAs were identified as differentially expressed in WT and were enriched in 472 Gene Ontology terms (355 biological processes, 89 cellular components and 29 molecular functions) and 18 Kyoto Encyclopedia of Genes and Genomes pathways. A lncRNA-miRNA-mRNA ceRNA network of WT consisting of with 32 lncRNAs, 14 miRNAs and 158 mRNAs was constructed, based on the bioinformatics analysis of the miR target prediction database and the miRNAcode, miRTarBase and TargetScan databases. Subsequently, three lncRNAs, three miRNAs and 17 mRNAs, which had a significant effect on the overall survival rate of patients with WT, were identified based on the survival analysis. The three lncRNAs were also differentially expressed in the late and early stages of WT and were validated using the GSE66405 dataset obtained from the Gene Expression Omnibus database. In conclusion, the present study generated a specific lncRNA-related ceRNA network of WT, which may provide a novel perspective on the molecular mechanisms underlying the progression and prognosis of the disease.

MiR-29c-3p, a target miRNA of LINC01296, accelerates tumor malignancy: therapeutic potential of a LINC01296/miR-29c-3p axis in ovarian cancer

As one of the main gynecological cancers, ovarian cancer (OC) has an unfavourable outcomes owing to its high recurrence and metastasis rate. Our previous studies have revealed that LINC01296 functions as an oncogene in OC, but the underlying mechanism has not been explored. The aim of this paper was to further investigate that how LINC01296 plays a role in OC. Through online software prediction, miR-29c-3p has been discriminated as the target miRNA of LINC01296 for further research, and subsequent luciferase assay confirmed bioinformatics prediction. Then the data obtained from the two databases (GSE119055 and GSE83693) were analyzed by GEO2R for differential gene analysis. The results indicated that the miR-29c-3p was lowly expressed in OC tissues than that in normal ovarian tissues, and its expression in recurrent OC tissues was lower than that in primary OC tissues. Simultaneously, Kaplan-Meier survival analysis illustrated that the lower expression of miR-29c-3p was interrelated to unfavourable outcomes of OC. Further, the qRT-PCR data revealed that the miR-29c-3p expression in OC cell lines (SKOV-3 and OVCAR-3) was markedly declined than that in normal control cells (IOSE80). Subsequently, the functional experiments, such as CCK8, colony formation and Transwell assays, prompted that inhibition of miR-29c-3p can obviously increase the proliferation, invasion and migration of OVCAR3 and SKOV3 cells compared with control group, while downregulation of LINC01296 showed an opposite result. It is worth noting that downregulation of LINC01296 can reverse the effect of miR-29c-3p suppression on OC cells. Finally, we detected the changes of EMT-related proteins by western blot experiment, and reached a similar conclusion that knockdown of LINC01296 reversed the EMT caused by miR-29c-3p inhibition. In sum up, the cancer-promoting function of LINC01296 was achieved by regulating the expression of miR-29c-3p, and LINC01296/miR-29c-3p axis mediates the mechanical regulation of EMT in OC cells, hoping to provide the novel biomarkers and possibilities for OC therapy.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.