Long noncoding RNA linc00346 promotes the malignant phenotypes of bladder cancer

Regulation of inflammatory response by LINC00346 via miR-25-3p-mediated modulation of the PTEN/PI3K/AKT/NF-κB pathway

Long intergenic non-coding RNA 346 (LINC00346) has been reported to be involved in the development of atherosclerosis and specific cancers by affecting signaling pathways. However, its function in inflammation has not been thoroughly studied. Therefore, its expression pattern and function were determined in the human macrophage-like cell line THP-1. Lipopolysaccharide (LPS) treatment induced the expression of LINC00346. LPS-induced NF-κB activation and proinflammatory cytokine expression were suppressed or enhanced by the overexpression or knockdown of LINC00346, respectively. Analyses using dual luciferase assay and decoy RNAs that could block RNA-RNA interactions indicated that LINC00346 improves phosphatase and tensin homolog (PTEN) expression by sponging miR-25-3p. Subsequently, PTEN suppresses phosphoinositide-3 kinase (PI3K)-mediated conversion of phosphatidylinositol-4,5-bisphosphate (PIP2) into phosphatidylinositol-3,4,5-trisphosphate (PIP3) as well as consequent activation of protein kinase B (AKT) and NF-κB. Interestingly, database analysis revealed that the expression levels of LINC00346 and PTEN were simultaneously decreased in breast cancer tissues. Further analyses conducted using a breast cancer cell line, MDA-MB-231, confirmed the functional relationship among LINC00346, miR-25-3p, and PTEN in LPS-induced activation of NF-κB. These results indicate that miR-25-3p-sponging activity of LINC00346 affects the balance between PTEN and PI3K as well as the downstream activation of AKT/NF-κB pathway in inflammatory conditions.

Epigenetic and Immunological Features of Bladder Cancer

Bladder cancer (BLCA) is one of the most common types of malignant tumors of the urogenital system in adults. Globally, the incidence of BLCA is more than 500,000 new cases worldwide annually, and every year, the number of registered cases of BLCA increases noticeably. Currently, the diagnosis of BLCA is based on cystoscopy and cytological examination of urine and additional laboratory and instrumental studies. However, cystoscopy is an invasive study, and voided urine cytology has a low level of sensitivity, so there is a clear need to develop more reliable markers and test systems for detecting the disease with high sensitivity and specificity. Human body fluids (urine, serum, and plasma) are known to contain significant amounts of tumorigenic nucleic acids, circulating immune cells and proinflammatory mediators that can serve as noninvasive biomarkers, particularly useful for early cancer detection, follow-up of patients, and personalization of their treatment. The review describes the most significant advances in epigenetics of BLCA.

A novel inflammation-related lncRNAs prognostic signature identifies LINC00346 in promoting proliferation, migration, and immune infiltration of glioma

In this study, a total of 13 inflammation-related lncRNAs with a high prognostic value were identified with univariate, multivariate Cox regression analysis, and LASSO analysis. LINC00346, which is one of the 13 lncRNAs identified, was positively associated with type 2 macrophage activation and the malignant degree of glioma. Fluorescence in situ hybridization (FISH) and immunohistochemical staining showed that LINC00346 was highly expressed in high-grade glioma, while type 2 macrophages key transcription factor STAT3 and surface marker CD204 were also highly expressed simultaneously. LINC00346 high-expression gliomas were more sensitive to the anti–PD-1 and anti-CTLA-4 therapy. LINC00346 was also associated with tumor proliferation and tumor migration validated by EdU, cell colony, formation CCK8, and transwell assays. These findings reveal novel biomarkers for predicting glioma prognosis and outline relationships between lncRNAs inflammation, and glioma, as well as possible immune checkpoint targets for glioma.

Aberrant expression of LINC00346 regulates cell migration and proliferation via competitively binding to miRNA-148a-3p/Dnmt1 in Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a common birth defect caused by dysplasia of neural crest cells in the gut. Long noncoding RNAs (lncRNAs) play an important role in cellular processes, including development and disease. Despite the known engagement of LINC00346 in several human diseases, its biological function in HSCR remains unknown.

METHODS

The relative expression levels of LINC00346, miR-148a-3p and Dnmt1 in HSCR colon tissues were detected by quantitative real-time PCR. Western blot assays were conducted to investigate the Dnmt1 protein expression level. Knockdown of LINC00346 and overexpression of miR-148a-3p in SH-SY5Y and SK-N-BE(2) cell lines was conducted. Cell proliferation and migration were detected by cell counting Kit-8 assays, 5-ethynyl-2'-deoxyuridine assays and transwell assays. Cell apoptosis was verified by flow cytometric analysis. Furthermore, the competing endogenous RNA (ceRNA) activity of LINC00346 on miR-148a-5p was investigated via bioinformatics analysis and luciferase reporter assays.

RESULT

Downregulation of LINC00346 and Dnmt1 was detected in HSCR tissues. Knockdown of LINC00346 and overexpression of miR-148a-3p in SK-N-BE(2) and SH-SY5Y cells inhibited cell migration and proliferation and promoted apoptosis. Moreover, the miR-148a-3p inhibitor rescued the downregulation of Dnmt1 in LINC00346 knockdown cell lines, which was evidence of the ceRNA regulatory mechanism of Dnmt1 by LINC00346.

CONCLUSIONS

LINC00346 was downregulated in HSCR colon tissues and acted as a ceRNA to regulate the expression of Dnmt1 in vitro. Together, these findings indicate that LINC00346 could affect the occurrence of HSCR by participating in the development of enteric neural crest cells.

LncRNA ARAP1-AS1 Promotes Bladder Cancer Development by Regulating the miR-3918/KIF20A Axis

This study is to clarify the effect of the long non-coding RNA ArfGAP with RhoGAP domain, ankyrin repeat and PH domain 1-antisense RNA 1 (ARAP1-AS1)/microRNA (miR)-3918/kinesin family member 20A (KIF20A) on bladder cancer cell function. ARAP1-AS1, miR-3918, and KIF20A expression levels in bladder cancer cells were determined using quantitative reverse transcription-polymerase chain reaction. The effects of ARAP1-AS1, miR-3918, and KIF20A on bladder cell activity, proliferation, apoptosis, and in vivo growth were examined using the cell counting kit-8, colony formation, caspase-3 activity, and xenograft tumor growth assays, respectively, in nude mice. The binding relationships among ARAP1-AS1, miR-3918, and KIF20A were analyzed using luciferase and RNA immunoprecipitation assays. ARAP1-AS1 and KIF20A were overexpressed in bladder cancer, while miR-3918 was underexpressed. The downregulation of ARAP1-AS1 or KIF20A expression significantly inhibited the viability and proliferation of cancer cells and promoted apoptosis, whereas low expression of miR-3918 or high expression of ARAP1-AS1/KIF20A showed the opposite effect. miR-3918 was sponged by ARAP1-AS1, and targeted KIF20A. In addition, miR-3918 expression was inversely correlated with ARAP1-AS1 and KIF20a expression levels in bladder cancer tissues. In addition, the rescue experiment showed that interference with miR-3918 could reverse the effect of low ARAP1-AS1 or KIF20A expression on bladder cancer cell malignancy. ARAP1-AS1 facilitates the malignant behavior of bladder cancer cells via the regulation of KIF20A expression by sponging miR-3918.

Roles of lncRNAs Mediating Wnt/β-Catenin Signaling in HCC

Hepatocellular carcinoma (HCC) is considered the second most deadly cancer worldwide. Due to the absence of early diagnostic markers and effective therapeutic approaches, distant metastasis and increasing recurrence rates are major difficulties in the clinical treatment of HCC. Further understanding of its pathogenesis has become an urgent goal in HCC research. Recently, abnormal expression of long noncoding RNAs (lncRNAs) was identified as a vital regulator involved in the initiation and development of HCC. Activation of the Wnt/β-catenin pathway has been reported to obviously impact cell proliferation, invasion, and migration of HCC. This article reviews specific interactions, significant mechanisms and molecules related to HCC initiation and progression to provide promising strategies for treatment.

New Insights into LINC00346 and its Role in Disease

Accumulating evidence has shown that long intergenic non-protein-coding RNA 346 (LINC00346) functions as an oncogene in the tumorigenesis of several cancers. The expression level of LINC00346 has been shown to be obviously correlated with prognosis, lymphoma metastasis, histological grade, TNM stage, tumor size and pathologic stage. LINC00346 has been found to regulate specific cellular functions by interacting with several molecules and signaling pathways. In this review, we summarize recent evidence concerning the role of LINC00346 in the occurrence and development of diseases. We also discuss the potential clinical utility of LINC00346, thereby providing new insight into the diagnosis and treatment of diseases. In addition, we further discuss the potential clinical utility of LINC00346 in the diagnosis, prognostication, and treatment of diseases.

High Level of Staufen1 Expression Confers Longer Recurrence Free Survival to Non-Small Cell Lung Cancer Patients by Promoting THBS1 mRNA Degradation

Stau1 is a pluripotent RNA-binding protein that is responsible for the post-transcriptional regulation of a multitude of transcripts. Here, we observed that lung cancer patients with a high Stau1 expression have a longer recurrence free survival. Strikingly, Stau1 did not impair cell proliferation in vitro, but rather cell migration and cell adhesion. In vivo, Stau1 depletion favored tumor progression and metastases development. In addition, Stau1 depletion strongly impaired vessel maturation. Among a panel of candidate genes, we specifically identified the mRNA encoding the cell adhesion molecule Thrombospondin 1 (THBS1) as a new target for Staufen-mediated mRNA decay. Altogether, our results suggest that regulation of THBS1 expression by Stau1 may be a key process involved in lung cancer progression.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

Long non-coding RNAs and their potential impact on diagnosis, prognosis, and therapy in prostate cancer: racial, ethnic, and geographical considerations

INTRODUCTION

Advances in high-throughput sequencing have greatly advanced our understanding of long non-coding RNAs (lncRNAs) in a relatively short period of time. This has expanded our knowledge of cancer, particularly how lncRNAs drive many important cancer phenotypes via their regulation of gene expression.

AREAS COVERED

Men of African descent are disproportionately affected by PC in terms of incidence, morbidity, and mortality. LncRNAs could serve as biomarkers to differentiate low-risk from high-risk diseases. Additionally, they may represent therapeutic targets for advanced and castrate-resistant cancer. We review current research surrounding lncRNAs and their association with PC. We discuss how lncRNAs can provide new insights and diagnostic biomarkers for African American men. Finally, we review advances in computational approaches that predict the regulatory effects of lncRNAs in cancer.

EXPERT OPINION

PC diagnostic biomarkers that offer high specificity and sensitivity are urgently needed. PC specific lncRNAs are compelling as diagnostic biomarkers owing to their high tissue and tumor specificity and presence in bodily fluids. Recent studies indicate that PCA3 clinical utility might be restricted to men of European descent. Further work is required to develop lncRNA biomarkers tailored for men of African descent.

LINC00346 Sponges miR-30c-2-3p to Promote the Development of Lung Adenocarcinoma by Targeting MYBL2 and Regulating CELL CYCLE Signaling Pathway

Background

LINC00346 has recently been reported to regulate the development of several cancer types, but its biological functions and underlying mechanisms in lung adenocarcinoma (LUAD) have not been elucidated. The purpose of this study was to investigate the molecular mechanism of LINC00346 in the progression of LUAD.

Methods

Bioinformatics was performed to find the target lncRNA, miRNA and mRNA, and the binding relationship between the target genes was verified by dual luciferase reporter gene and RIP assays. Fluorescence in situ hybridization was used to detect the location of LINC00346 in LUAD tissues. The expressions of LINC00346, miR-30c-2-3p and MYBL2 in each group were detected by qRT-PCR, and western blot was performed to detect expressions of MYBL2 and CELL CYCLE related proteins. Proliferation, metastasis, apoptosis and cell cycle of LUAD cells were detected by CCK-8, colony formation, Transwell and flow cytometry assays, respectively. Mouse xenograft models were established to further determine the effects of LINC00346 on LUAD tumor growth in vivo.

Results

LINC00346 was upregulated in LUAD tissues and cells and was mainly localized in the cytoplasm. Knockdown of LINC00346 inhibited tumor growth in vivo, proliferation, metastasis and cell cycle progression, while induced apoptosis. LINC00346 sponged miR-30c-2-3 by targeting MYBL2 and regulating CELL CYCLE signaling pathway. Inhibiting miR-30c-2-3p or overexpressing MYBL2 could reverse the inhibitory effect of LINC00346 knockdown on LUAD process.

Conclusions

LINC00346 as a ceRNA played a carcinogenic role in the development of LUAD via miR-30c-2-3p/MYBL2 axis regulating the CELL CYCLE signaling pathway. The study generally elucidated the mechanism by which LINC00346 regulated the development of LUAD, providing new ideas for the diagnosis and treatment of LUAD guided by lncRNA.

Biological functions and clinical significance of long noncoding RNAs in bladder cancer

Bladder cancer (BCa) is one of the 10 most common cancers with high morbidity and mortality worldwide. Long noncoding RNAs (lncRNAs), a large class of noncoding RNA transcripts, consist of more than 200 nucleotides and play a significant role in the regulation of molecular interactions and cellular pathways during the occurrence and development of various cancers. In recent years, with the rapid advancement of high-throughput gene sequencing technology, several differentially expressed lncRNAs have been discovered in BCa, and their functions have been proven to have an impact on BCa development, such as cell growth and proliferation, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and drug-resistance. Furthermore, evidence suggests that lncRNAs are significantly associated with BCa patients' clinicopathological characteristics, especially tumor grade, TNM stage, and clinical progression stage. In addition, lncRNAs have the potential to more accurately predict BCa patient prognosis, suggesting their potential as diagnostic and prognostic biomarkers for BCa patients in the future. In this review, we briefly summarize and discuss recent research progress on BCa-associated lncRNAs, while focusing on their biological functions and mechanisms, clinical significance, and targeted therapy in BCa oncogenesis and malignant progression.

Long Noncoding RNA KCNMB2-AS1 Promotes SMAD5 by Targeting miR-3194-3p to Induce Bladder Cancer Progression

Purpose

Bladder cancer is a common malignant tumor of the urinary system, with the fourth-highest incidence of male malignant tumors in Europe and the United States. So far, the mechanism of bladder cancer progression and metastasis has not been clarified. The aim of our study was to validate the way of long noncoding RNA (lncRNA) KCNMB2-AS1 on the metabolism and growth of bladder cancer cells by miR-3194-3p/SMAD5.

Patients and Methods

The Gene Expression was analyzed by qRT-PCR in bladder cancer tissues and cell lines, with the highly expressed KCNMB2-AS1 screened out. Cell proliferation was detected by Edu staining and clone formation assay, cell migration, and invasion by wound healing and transwell assays. Cell stemness was determined by assessing sphere-forming ability and stemness marker. Correlation between miRNA and lncRNA/gene was verified by dual‐luciferase assay and RIP, and the effect of KCNMB2-AS1 on bladder cancer growth by nude mice tumor formation experiment.

Results

Here, we revealed the increased level of KCNMB2-AS1 in bladder cancer for the first time. Knockdown of KCNMB2-AS1 in vitro prevented the ability of proliferation, metastasis, and stemness of cancer cells. In vivo, the silencing of KCNMB2-AS1 also prevented tumor growth in vivo. Next, we revealed that KCNMB2-AS1 could interact with miR-3194-3p and uncovered that SAMD5 was a downstream target of miR-3194-3p.

Conclusion

In conclusion, KCNMB2-AS1 mediated the bladder cancer cells progress by regulating the miR-3194-3p/SAMD5 signal pathway, which would provide a new target for bladder cancer research.

LINC00346 regulates glycolysis by modulation of glucose transporter 1 in breast cancer cells

Most cancer cells preferentially metabolize glucose by glycolysis rather than oxidative phosphorylation to proliferate efficiently. LncRNAs have been proposed as crucial regulators in pathophysiological processes including cell growth, apoptosis and glucose metabolism. However, little is known regarding the specific role of LINC00346 in regulating glucose metabolism in breast cancer. LINC00346 and miR-148a/b expression in breast cancer cells was detected by qRT-PCR. The relationships between LINC00346, glucose transporter 1 (GLUT1) and miR-148a/b in breast cancer cells were explored by luciferase reporter assay. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry analysis, respectively. Glycolysis was detected by measuring the glucose uptake and lactate production. Results showed that LINC00346 was over-expressed while miR-148a/b was low-expressed in breast cancer cells. miR-148a/b were direct targets of LINC00346 in breast cancer cells. LINC00346 knockdown inhibited cell proliferation and glycolysis, and induced apoptosis by upregulating miR-148a/b in breast cancer cells. Furthermore, we found that LINC00346 knockdown repressed GLUT1 expression in breast cancer cells by upregulating miR-148a/b. In conclusion, LINC00346 knockdown suppressed breast cancer cell glycolysis by upregulating miR-148a/b and repressing GLUT1 expression.

Comprehensive Analysis of LincRNAs in Classical and Basal-Like Subtypes of Pancreatic Cancer

Pancreatic ductal adenocarcinomas (PDAC) belong to the deadliest malignancies in the western world. Mutations in TP53 and KRAS genes along with some other frequent polymorphisms occur almost universally and are major drivers of tumour initiation. However, these mutations cannot explain the heterogeneity in therapeutic responses and differences in overall survival observed in PDAC patients. Thus, recent classifications of PDAC tumour samples have leveraged transcriptome-wide gene expression data to account for epigenetic, transcriptional and post-transcriptional mechanisms that may contribute to this deadly disease. Intriguingly, long intervening RNAs (lincRNAs) are a special class of long non-coding RNAs (lncRNAs) that can control gene expression programs on multiple levels thereby contributing to cancer progression. However, their subtype-specific expression and function as well as molecular interactions in PDAC are not fully understood yet. In this study, we systematically investigated the expression of lincRNAs in pancreatic cancer and its molecular subtypes using publicly available data from large-scale studies. We identified 27 deregulated lincRNAs that showed a significant different expression pattern in PDAC subtypes suggesting context-dependent roles. We further analyzed these lincRNAs regarding their common expression patterns. Moreover, we inferred clues on their functions based on correlation analyses and predicted interactions with RNA-binding proteins, microRNAs, and mRNAs. In summary, we identified several PDAC-associated lincRNAs of prognostic relevance and potential context-dependent functions and molecular interactions. Hence, our study provides a valuable resource for future investigations to decipher the role of lincRNAs in pancreatic cancer.

Silencing of lncRNA LINC00346 Inhibits the Proliferation and Promotes the Apoptosis of Colorectal Cancer Cells Through Inhibiting JAK1/STAT3 Signaling

Purpose

The study was aimed to investigate the effect and mechanism of lncRNA LINC00346 on cell proliferation and apoptosis of colorectal cancer (CRC).

Methods

The expression of lncRNA LINC00346 in CRC tissues and cells was detected by qRT-PCR. LINC00346 was overexpressed and silenced in HT29 and LoVo cells by the transfection of pcDNA-LINC00346 and si-LINC00346. The proliferation of CRC cells was detected by CCK-8 and colony-formation assay. The apoptosis was detected by flow cytometry assay. The expression of apoptosis-associated proteins (Caspase-3, Bcl-2, Bax) and JAK1/STAT3 signaling-associated proteins (JAK1, STAT3, p-JAK1, p-STAT3) was detected by Western blot. The tumor growth was detected in mice subcutaneous injected with transfected HT29 cells.

Results

LINC00346 was significantly upregulated in CRC tissues and cells. Overexpression of LINC00346 significantly increased the OD₄₅₀ values, number of colonies, decreased the apoptosis rate, upregulated Bcl-2, and downregulated Caspase-3 and Bax in HT29 and LoVo cells. Knockdown of LINC00346 exerted opposite results of proliferation and apoptosis on HT29 and LoVo cells. The expression levels of JAK1/JAK1 and p-STAT3/STAT3 were upregulated by LINC00346 overexpression. Tofacitinib (JAK1 inhibitor) reversed the tumor-promoting effect of LINC00346 overexpression on CRC cells. In vivo experiments further validated that LINC00346 overexpression promoted the growth of CRC xenograft tumors.

Conclusion

LncRNA LINC00346 promoted the proliferation and inhibited the apoptosis of CRC cells through activating JAK1/STAT3 signaling.

Comprehensive analysis of competitive endogenous RNAs network reveals potential prognostic lncRNAs in gastric cancer

Long non-coding RNAs (lncRNAs) are key regulators of a range of human diseases, including various cancers, with multiple previous studies having explored lncRNA dysregulation in the context of gastric cancer (GC). The present study sought to expand upon these previous results by downloading lncRNA, mRNA, and microRNA (miRNA) expression profiles derived from 180 GC tissues and 24 normal control tissues within the Cancer Genome Atlas (TCGA) database. These datasets were then interrogated to identify GC-related differentially expressed (DE) RNAs (|fold change| ≥ 2, FDR< 0.01), leading to the identification of 1946 DE lncRNAs, 123 DE miRNAs, and 3159 DE mRNAs. These results were then used to generate a putative GC-related competitive endogenous RNA (ceRNA) network composed of 131 lncRNAs, 9 miRNAs, and 78 mRNAs. Subsequent survival analyses based upon this network revealed 17 of these lncRNAs to be significantly associated with GC patient survival (P < 0.05). Further multivariable Cox regression and lasso analyses allowed for the construction of an 8-lncRNA risk score that was able to effectively predict GC patient survival with good discriminative ability. The Kaplan-Meier Plotter database further confirmed that network hub genes that were related to these 8 lncRNAs were associated with GC patient prognosis (P < 0.05). As the ceRNA network in the present study was constructed with a focus on both disease stage and differential gene expression, it represents a key resource that will offer valuable insights into the mechanistic roles of ceRNA pathways in GC development and progression.

Role of ANKHD1/LINC00346/ZNF655 Feedback Loop in Regulating the Glioma Angiogenesis via Staufen1-Mediated mRNA Decay

Accumulating evidence shows that long noncoding RNA (lncRNA) dysregulation plays a critical role in tumor angiogenesis. Glioma is characterized by abundant angiogenesis. Herein, we investigated the expression and function of LINC00346 in the regulation of glioma angiogenesis. The present study first demonstrated that ANKHD1 (ankyrin repeat and KH domain-containing protein 1) and LINC00346 were significantly increased in glioma-associated endothelial cells (GECs), whereas ZNF655 (zinc finger protein 655) was decreased in GECs. Meanwhile, ANKHD1 inhibition, LINC00346 inhibition, or ZNF655 overexpression impeded angiogenesis of GECs. Moreover, ANKHD1 targeted LINC00346 and enhanced the stability of LINC00346. In addition, LINC00346 bound to ZNF655 mRNA through their Alu elements so that LINC00346 facilitated the degradation of ZNF655 mRNA via a STAU1 (Staufen1)-mediated mRNA decay (SMD) mechanism. Futhermore, ZNF655 targeted the promoter region of ANKHD1 and formed an ANKHD1/LINC00346/ZNF655 feedback loop that regulated glioma angiogenesis. Finally, knockdown of ANKHD1 and LINC00346, combined with overexpression of ZNF655, resulted in a significant decrease in new vessels and hemoglobin content in vivo. The results identified an ANKHD1/LINC00346/ZNF655 feedback loop in the regulation of glioma angiogenesis that may provide new targets and strategies for targeted therapy against glioma.

Long non-coding RNA LINC00346 contributes to cisplatin resistance in nasopharyngeal carcinoma by repressing miR-342-5p

Cisplatin has been used as the first-line chemotherapy to treat advanced nasopharyngeal carcinoma (NPC), while acquired cisplatin resistance resulting from epigenetic regulation is not well understood. The relative expression of LINC00346 was detected in healthy persons, cisplatin-sensitive (CS) patients and cisplatin-resistant (CR) patients. The regulatory effect of LINC00346 on the proliferation was detected by cell-counting kit-8. Apoptosis was assayed by histone/DNA ELISA and Caspase-3 activity. Clonal formation and cisplatin resistance were also deciphered. Luciferase reporter and RNA immunoprecipitation assay were adopted to study the interaction between LINC00346 and miR-342-5p. LINC00346 was highly expressed in NPC patients, especially in CR patients, which was associated with cisplatin resistance and poor prognosis. Inhibition of LINC00346 expression promoted cisplatin sensitivity of NPC cells, while LINC00346 over-expression promoted cisplatin resistance of NPC cells. miR-342-5p expression was negatively correlated with cisplatin resistance, and microRNA-342-5p siRNAs treatment could rescue the cisplatin resistance diminished by LINC00346 inhibition. It was further found that miR-342-5p was negatively regulated by LINC00346. In conclusion, LINC00346 regulates the cisplatin resistance of NPC cells by inhibiting miR-342-5p, which could provide a potential target for chemotherapy resistance.

Silencing of Long Noncoding RNA LINC00346 Inhibits the Tumorigenesis of Colorectal Cancer Through Targeting MicroRNA-148b

PURPOSE

This study was aimed to explore the regulatory effect of long noncoding RNA LINC00346 (LINC00346) on colorectal cancer (CRC) and the potential molecular mechanisms.

METHODS

The expression of LINC00346 and microRNA-148b (miR-148b) in CRC tissues and cells was detected by qRT-PCR. LINC00346 was overexpressed and silenced in HT29 and HCT116 cells by the transfection of pcDNA-LINC00346 and si-LINC00346, respectively. The cell proliferation, migration, invasion, and apoptosis were analyzed by cell counting kit-8 (CCK-8), wound-healing, transwell, and flow cytometry assay, respectively. The targeting relationship between LINC00346 and miR-148b was predicted by TargetScan and determined by dual-luciferase reporter assay. A tumor xenograft model was established in mice to evaluate the tumor growth in vivo.

RESULTS

The expression of LINC00346 was up-regulated in CRC tissues and cells. The expression of LINC00346 was positively associated with the TNM stage, lymphoma metastasis and histological grade. Overexpression of LINC00346 promoted the proliferation, migration and invasion and inhibited the apoptosis of HT29 and HCT116 cells. MiR-148b was a target of LINC00346. Silencing of miR-148b reversed the anti-tumor effect of si-LINC00346 on CRC cells. Furthermore, silencing of LINC00346 inhibited the tumor growth in mice through up-regulating miR-148b.

CONCLUSION

Silencing of LINC00346 inhibited the proliferation, migration and invasion, and promoted the apoptosis of CRC cells through targeting miR-148b.

Long Non-Coding RNA BCAR4 Binds to miR-644a and Targets TLX1 to Promote the Progression of Bladder Cancer

Background

Bladder cancer is a serious threat to human health. It is meaningful to study the pathogenesis of bladder cancer. Long non-coding RNAs (lncRNAs) are reported to promote or inhibit bladder cancer development. However, the role of lncRNA BCAR4 in the regulation of bladder cancer remains unclear.

Purpose

This study was to explore the role of lncRNA BCAR4 in the progression of bladder cancer cell.

Methods

RT-PCR was used to examine the expression of BCAR4 and miR-644a. CCK8 assay, colony formation assay, Transwell assay were used to detect the progression of bladder cancer cells after transfecting of indicated plasmids.

Results

The expression of BCAR4 was higher in bladder cancer cell lines than normal urothelial cell line. Moreover, the expression of BCAR4 was associated with the advanced stage and metastasis of bladder cancer. Through knockdown of BCAR4, we discovered that knockdown of BCAR4 significantly decreased the proliferation, migration and invasive abilities of bladder cancer cells. Mechanically, we showed that BCAR4 can bind to miR-644a directly and targets TLX1. Moreover, we also showed that miR-644a was also highly expressed in bladder cancer cells and inhibition of miR-644a or overexpression of TLX1 can increased the migration abilities of bladder cancer caused by knockdown of BCAR4.

Conclusion

We showed that BCAR4 sponged miR-644a to modulate the expression of TLX1 and promote bladder cancer development.

LINC00346 Acts as a Competing Endogenous RNA Regulating Development of Hepatocellular Carcinoma via Modulating CDK1/CCNB1 Axis

Hepatocellular carcinoma (HCC) is one of the important types of liver cancer. LncRNA is an important regulatory factor that regulates many biological processes such as tumor cells during tumorigenesis and metastasis. LINC00346 has been associated with various types of liver cancer, but its role and regulatory mechanism in HCC remain unclear. In our study, we found the LINC00356-miR-199a-3p-CDK1/CCNB1 axis through bioinformatics analysis. The expressions of LINC00356, miR-199a-3p, CDK1, and CCNB1 in HCC and normal hepatocytes were determined by qRT-PCR and WB. The results showed that LINC00356, CDK1 and CCNB1 were highly expressed in HCC, while miR-199a-3p was lowly expressed. Dual luciferase reporter gene assay, RIP and RNA-pull down assays demonstrated the targeted binding relationship of LINC00346-miR-199a-3p-CDK1/CCNB1. Overexpressing LINC00460 and silencing miR-199a-3p promoted cell invasion, inhibited apoptosis of HCC, and arrested the cell cycle in S phase while opposite results were obtained when silencing LINC00346, CDK1, and CCNB1. LINC00346 indirectly affects liver cancer by promoting the expression of CDK1/CCNB1 through competitive adsorption of miR-199a-3p. In addition, the study also demonstrated that overexpression of LINC00346 indirectly inhibited the expression of p53 and p21 proteins by promoting CDK1/CCNB1 expressions, thereby blocking the p53 signaling pathway. These results proved that LINC00346 could regulate the expression of CDK1/CCNB1 through the competitive adsorption of miR-199a-3p, thereby affecting the p53 signaling pathway and finally regulating the apoptosis, invasion and cell cycle of HCC cells. In conclusion, LINC00346 can be used as a tumor promoter and potential therapeutic target for HCC metastasis and prognosis.

WBSCR22 Competes with Long Non-coding RNA Linc00346 for miR-509-5p Binding Site to Regulate Cancer Stem Cell Phenotypes of Colorectal Cancer

Various Long non-coding RNAs (lncRNAs) and MicroRNAs (miRNAs) have been demonstrated to be involved in colorectal cancer stem cells (CSCs). WBSCR22 is a key gene we previously found that functions in colorectal cancer (CRC). This paper aims to investigate the effects of WBSCR22 and its corresponding miRNA and lncRNA in CRC. The expression of WBSCR22 was detected by Western blot and qRT-PCR analysis. Tumor sphere formation assays, CCK-8 analysis, and Transwell assays were applied to examine the colorectal cancer stem cell properties. Luciferase assay and biotin RNA pulldown assay were used to detect the interaction between miR-509-5p and WBSCR22/Linc00346. WBSCR22 is highly expressed in CRC and correlates with poor prognosis. Knockdown of WBSCR22 decreased the sphere-forming capacities, cell proliferation, and invasion abilities. WBSCR22 was negatively regulated by miR-509-5p. Linc00346 promoted the expression of WBSCR22 by adsorbing miR-509-5p. The Linc00346/miR-509-5p/WBSCR22 signal axis regulated the characteristics of colon cancer stem cells. Linc00346 regulated the expression of WBSCR22 by binding to miR-509-5p, thereby monitoring the characteristics of colorectal cancer stem cells. Thus, WBSCR22, Linc00346, and miR-509-5p might be utilized as potential targets for clinical diagnosis and treatment of CRC.

Long non-coding RNA in bladder cancer

Bladder cancer (BC) is the ninth most common malignant disease and ranks fourteenth in cancer mortality worldwide. Moreover, among cancers, the incidence and mortality of BC in males increased to the 6th and 9th place, respectively. The overall survival (OS) declines dramatically as the cancer progresses, especially when urothelial cells transition from noninvasive to invasive. It is well known that epithelial cells can acquire invasive properties and a propensity to metastasize through the epithelial-to-mesenchymal transition (EMT) process in tumourigenesis and progression. However, the potential molecular mechanisms and key pathways are still unclear. As the sequencing technology advances, long non-coding RNAs (lncRNAs) have been proven to play an important role in regulating biological processes and cellular pathways. Here, we reviewed important lncRNAs, such as H19, UCA1 and MALAT1, that participate in the malignant phenotype of BC and regulate EMT signalling networks in the invasion-metastasis cascade during BC development. We further discuss MALAT1, PCAT-1 and SPRY4-IT1, and also urine and blood exosomal H19 and PTENP as potential noninvasive biomarkers. Moreover, antisense oligonucleotides (ASOs) and a double-stranded DNA plasmid (BC-819) have been designed for use in preclinical cancer models and clinical trials in patients. Therefore, the results of investigations have gradually prompted the utility of lncRNAs.

p53-Regulated Long Noncoding RNA PRECSIT Promotes Progression of Cutaneous Squamous Cell Carcinoma via STAT3 Signaling

Long noncoding RNAs (lncRNAs) have emerged as putative biomarkers and therapeutic targets in cancer. The role of lncRNA LINC00346 in cutaneous squamous carcinoma (cSCC) was examined. The expression of LINC00346 was up-regulated in cSCC cells compared with normal human epidermal keratinocytes. Elevated expression of LINC00346 was noted in tumor cells in cSCC tissue sections in vivo, as compared with cSCC in situ, and actinic keratosis by RNA in situ hybridization; and the expression in seborrheic keratosis and normal skin was very low. Immunohistochemical analysis of cSCC tissue sections and functional assays of cSCC cells in culture showed that LINC00346 expression is down-regulated by p53. Knockdown of LINC00346 inhibited invasion of cSCC cells in culture and suppressed growth of human cSCC xenografts in vivo. Knockdown of LINC00346 inhibited expression of activated STAT3 and resulted in down-regulation of the expression of matrix metalloproteinase (MMP)-1, MMP-3, MMP-10, and MMP-13. Based on these observations LINC00346 was named p53 regulated carcinoma-associated STAT3-activating long intergenic non-protein coding transcript (PRECSIT). These results identify PRECSIT as a new p53-regulated lncRNA, which promotes progression of cSCC via STAT3 signaling.

LINC00346 promotes hepatocellular carcinoma progression via activating the JAK-STAT3 signaling pathway

Hepatocellular carcinoma (HCC) remains the most common malignant tumor worldwide. Long noncoding RNAs can modulate various tumorigenic processes. In addition, growing evidence has indicated tha the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is activated in multiple cancers, including HCC. Recently, it was found that LINC00346 can participate in several cancers. Nevertheless, the biological roles of LINC00346 in HCC have been barely investigated. In this study, the function of LINC00346 was specifically concentrated upon. We observed that LINC00346 was obviously elevated in HCC cells (Bel7404, Huh-6, HepG2, and QGY-7703 cells). Then, Bel7404 and HepG2 cells were overexpressed with LINC00346. Overexpression of LINC00346 repressed HCC cell survival and cell proliferation. In addition, apoptosis of Bel7404 and HepG2 cells was triggered by LINC00346 upregulation. Bel7404 and HepG2 cell cycle was arrested in the G1 phase by LINC00346. Meanwhile, we conducted wound-healing assay and Transwell invasion assays. As shown, we observed that the migratory and invasive capacities of Bel7404 and HepG2 cells were remarkably restrained by the increase of LINC00346. Moreover, we showed that LINC00346 overexpression activated the JAK-STAT3 pathway, which is involved in many cancers. Afterward, in vivo experiments were utilized and we proved that LINC00346 was able to induce HCC tumor growth via activating the JAK-STAT3 pathway. To conclude, we revealed the potential possibility of developing LINC00346 as an indicator for HCC.

Long non-coding RNA LINC00346 promotes pancreatic cancer growth and gemcitabine resistance by sponging miR-188-3p to derepress BRD4 expression

BACKGROUND

Long non-coding RNA LINC00346 has been recently suggested as a prognostic marker in pancreatic cancer. However, its biological function in pancreatic cancer has not yet been determined. In this study, we attempted to ascertain the role of LINC00346 in regulating the aggressiveness of pancreatic cancer.

METHODS

The effects of overexpression and knockdown of LINC00346 on the proliferation, cell cycle progression, apoptosis, and gemcitabine resistance were investigated. Bioinformatic analysis, luciferase reporter assay, and RNA immunoprecipitation assay were performed to search for potential microRNAs (miRs) that can interact with LINC00346.

RESULTS

Overexpression of LINC00346 significantly enhanced the proliferation, colony formation, and tumorigenesis of pancreatic cancer cells. Conversely, knockdown of LINC00346 suppressed pancreatic cancer cell proliferation and caused a cell-cycle arrest at the G2/M-phase. Depletion of LINC00346 also enhanced gemcitabine sensitivity in pancreatic cancer cells both in vitro and in vivo. Mechanistic investigation revealed that LINC00346 acted as a sponge for miR-188-3p and blocked the repression of BRD4 by miR-188-3p in pancreatic cancer cells. Clinical evidence indicated a negative correlation between LINC00346 and miR-188-3p in pancreatic cancer specimens. Rescue experiments showed that LINC00346 attenuated the growth-suppressing and chemosensitizing effects of miR-188-3p on pancreatic cancer cells. In addition, silencing of BRD4 significantly inhibited LINC00346-induced pancreatic cancer cell proliferation and colony formation.

CONCLUSIONS

LINC00346 shows the ability to promote pancreatic cancer growth and gemcitabine resistance, which is in part mediated by antagonization of miR-188-3p and induction of BRD4. Targeting LINC00346 may improve gemcitabine-based therapeutic efficacy.

Long noncoding RNAs in cancer cells

Long noncoding RNA (lncRNA) has recently been investigated as key modulators that regulate many biological processes in human cancers via diverse mechanisms. LncRNAs can interact with macromolecules such as DNA, RNA, or protein to exert cellular effects and to act as either tumor promoters or tumor suppressors in various malignancies. Moreover, the aberrant expression of lncRNAs may be detected in multiple cancer phenotypes by employing the rapidly developing modern gene chip technology and bioinformatics analysis. Herein, we highlight the mechanisms of action of lncRNAs, their functional cellular roles and their involvement in cancer progression. Finally, we provide an overview of recent progress in the lncRNA field and future potential for lncRNAs as cancer diagnostic markers and therapeutics.

Integrated analysis of lncRNA-associated ceRNA network reveals potential biomarkers for the prognosis of hepatitis B virus-related hepatocellular carcinoma

Background

There is evidence that abnormal expression of lncRNAs is associated with hepatitis B virus (HBV) infection-induced hepatocellular carcinoma (HCC). However, the mechanisms remain not fully elucidated. The study aimed to identify novel lncRNAs and explore their underlying mechanisms based on the ceRNA hypothesis.

Methods

The RNA and miRNA expression profiling in 20 tumor and matched adjacent tissues from HBV–HCC patients were retrieved from the Gene Expression Omnibus database under accession numbers GSE77509 and GSE76903, respectively. Differentially expressed lncRNAs (DELs), miRNAs (DEMs), and genes (DEGs) were identified using the EdgeR package. Protein–protein interaction (PPI) network was constructed for DEGs followed by module analysis. The ceRNA network was constructed based on interaction relationships between miRNAs and mRNAs/lncRNAs. The functions of DEGs were predicted using DAVID and BinGO databases. The prognosis values (overall survival [OS] and recurrence-free survival [RFS]) of ceRNA network genes were determined using The Cancer Genome Atlas (TCGA) data with Cox regression analysis and Kaplan–Meier method.

Results

The present study screened 643 DELs, 83 DEMs, and 1,187 DEGs. PPI network analysis demonstrated that CDK1 and CCNE1 were hub genes and extracted in functionally related modules. E2F2, CDK1, and CCNE1 were significantly enriched into cell cycle pathway. FAM182B-miR-125b-5p-E2F2 and LINC00346-miR-10a-5p-CDK1/CCNE1 ceRNA axes were obtained by constructing the ceRNA network. Patients with high expressions of DELs and DEGs in the above ceRNA axes had poor OS, while patients with the high expression of DEMs possessed excellent OS. CDK1 was also an RFS-related biomarker, with its high expression predicting poor RFS. The upregulation of LINC00346 and CDK1 but the downregulation of miR-10a-5p in HCC was validated in other microarray datasets and TCGA database.

Conclusion

The LINC00346-miR-10a-5p-CDK1 axis may be an important mechanism for HBV-related HCC, and genes in this ceRNA axis may be potential prognostic biomarkers and therapeutic targets.

High LINC01605 expression predicts poor prognosis and promotes tumor progression via up-regulation of MMP9 in bladder cancer

The advent of high-throughput sequencing methods has facilitated identification of novel long non-coding RNAs (lncRNAs), which have been demonstrated to play an important role in multiple tumors. Moreover, with the assistance of bioinformatics analysis, LINC01605 has been found to be up-regulated in bladder cancer (BC) tissues compared with normal tissues. Hence, the present study was to explore its specific biological role and related mechanism in BC. The relative expression level of LINC01605 was measured in a cohort of BC tissues with matched normal tissues as well as human BC cell lines by quantitative real-time PCR (qRT-PCR). Survival analysis was performed to explore the relationship between LINC01605 expression and the prognosis of BC patients. The biological function of LINC01605 was studied in vitroand in vivo, by means of CCK-8 assay, colony formation assay, transwell assay, and tumor xenografts mice model. LINC01605 was found to be frequently highly expressed in both human BC cells and tissues. Survival analysis indicated that high LINC01605 expression was associated with higher histological grade and clinical stages. In addition, down-regulated LINC01605 in BC cells could significantly inhibit the abilities of proliferation, migration, and invasion in vitro and knockdown of LINC01605 in subcutaneous xenograft tumor model could impede tumorigenesis in vivo. Mechanistically, LINC01605 could activate epithelial–mesenchymal transition (EMT) signaling pathway and promote the expression of matrix metallopeptidase (MMP) 9 (MMP9). In summary, our results shed light on that LINC01605, as a new prognostic biomarker, could promote the proliferation, migration, and invasion of BC cells via activating EMT signaling pathway and up-regulating MMP9 expression.

Long non-coding RNA expression in bladder cancer

The advent of novel high-throughput sequencing methods has facilitated identification of non-coding RNAs with fundamental roles in cellular biological and pathological conditions. A group of these consisting of at least 200 nucleotides are called long non-coding RNAs (lncRNAs). Their participation in the pathogenesis of cancer has been highlighted in recent years. Bladder cancer, one of the most prevalent cancers worldwide, exhibits altered expression levels of several lncRNAs. Several in vitro and in vivo studies have assessed the effects of silencing RNAs on cancer cell phenotypes and in vivo tumor growth. For instance, in vitro studies have shown that nuclear paraspeckle assembly transcript 1 (NEAT1), promoter of CDKN1A antisense DNA damage-activated RNA(PANDAR) and metastasis-associated lung adenocarcinoma transcript 1(MALAT1) have oncogenic effects while Maternally expressed 3 (MEG3) and BRAF activated non-coding RNA (BANCR) are tumor suppressors. Analysis of these data will help to identify a panel of lncRNAs that can be potentially used for both early detection and prognosis in bladder cancer patients. Here, we review the roles of several lncRNAs in the oncogenesis, tumor suppression, early detection, and prognosis of bladder cancer.

Clinical Values of Long Non-coding RNAs in Bladder Cancer: A Systematic Review

Background: Increasing evidence shows that dysregulated expression of long non-coding RNAs (lncRNAs) can serve as diagnostic or prognostic markers in bladder cancer. The aim of this study was to evaluate the clinical values of dysregulated lncRNAs in bladder cancer.

Methods: Eligible studies were systematically searched in PubMed, Embase, and Web of Science databases from inception to December 2017. Odds ratios (OR) were calculated to investigate the correlation between lncRNAs and clinicopathological parameters. Pooled hazard ratios (HR) and 95% confidence interval (CI) were calculated to explore the prognostic value of lncRNAs in bladder cancer. Pooled diagnostic parameters were also calculated to estimate the performance of lncRNAs in diagnosing bladder cancer. All statistical analyses were performed by using STATA 13.1 program.

Results: A total of 37 relevant studies were included to the present systematic review according to the inclusion and exclusion criteria, including 26 on clinicopathological parameters, 19 on prognosis, and 7 on diagnosis. For clinicopathological parameters, MALAT1 expression was significantly associated with lymph node metastasis (OR = 2.731; 95% CI: 1.409–5.292; p = 0.003), and high-level expression of XIST was related to larger tumor size (OR = 2.473; 95% CI: 1.159–5.276; p = 0.019) and higher TNM stage (OR = 0.400; 95% CI, 0.184–0.868; p = 0.020). For the prognostic values, the most significant association was observed between increased expressions of SPRY4-IT1 and poor overall survival (OS) (HR = 3.716; 95% CI: 2.084–6.719; p < 0.001); high MALAT1 expression was significantly associated with poor OS (HR = 1.611; 95% CI: 1.076–2.412; p = 0.020). For the diagnostic values, UCA1 expression profile achieved a combined AUC of 0.92, with sensitivity of 0.84 and specificity of 0.89 in distinguishing patients with bladder cancer from non-cancerous controls.

Conclusions: In summary, systematic review elaborated that abnormal lncRNAs expression can serve as potential markers for prognostic evaluation in bladder cancer patients. In addition, the diagnostic meta-analysis concluded that abnormally expressed UCA1 can function as potential diagnostic markers for bladder cancer.