Upregulation of the long non-coding RNA CASC9 as a biomarker for squamous cell carcinoma

Linc00662 sponges miR-15b-5p to promote hypopharyngeal squamous cell carcinoma progression by facilitating cancer stem cell-like phenotypes

Background: Long non-coding RNAs (lncRNAs) are associated with multiple head and neck tumors and play important roles in cancer. This study explored the molecular mechanism of Linc00662 in hypopharyngeal squamous cell carcinoma (HSCC). Methods: Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect gene expression in HSCC tissues. The viability and proliferation of tumor cells were measured using CCK-8 assays. HSCC cell apoptosis was measured using flow cytometry and western blotting. Cell stemness was examined using the sphere formation assay. A xenograft tumor model was established to investigate the role of Linc00662 in vivo. Results: The expression level of Linc00662 in HSCC tissues was significantly higher than that in adjacent normal tissues. The expression of Linc00662 had no significant relationship with the tumor stage. Patients with high Linc00662 expression were found to have shorter overall survival than those with low Linc00662 expression. Linc00662 over-expression promoted cell viability and inhibited apoptosis. Using online databases and a dual luciferase reporter, miR-15b-5p was confirmed as a potential downstream sponge of Linc00662. Moreover, Linc00662 was negatively associated with miR-15b-5p in HSCC cells. Depletion of miR-15b-5p can reverse the function of Linc00662 in vivo and in vitro. Furthermore, Linc00662 promotes tumor growth, which was abolished by miR-15b-5p mimics. Importantly, the stemness of cancer stem cells was mediated by the Linc00662/miR-15b-5p axis. Conclusion: Patients with HSCC with high Linc00662 showed poor prognosis and high Linc00662 induced stemness of tumor cells by targeting miR-15b-5p. Linc00662 may serve as a novel diagnostic and target marker for head and neck squamous cell carcinoma.

Long non-coding RNAs involved in retinoblastoma

INTRODUCTION

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

MATERIAL AND METHODS

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

CONCLUSION

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

Diagnostic value of lncRNA HOTAIR as a biomarker for detecting and staging of non-small cell lung cancer

BACKGROUND

Since the role of long non-coding RNA (lncRNA) HOTAIR is yet to be established in non-small cell lung cancer (NSCLC), we tried to explore the expression of lncRNA HOTAIR in NSCLC and evaluate the correlation between the combined detection of lncRNA HOTAIR and routine tumour markers and the pathological staging of lung cancer.

METHODS

This study prospectively included 148 patients with NSCLC selected from our hospital from January 2017 to September 2020 as the lung cancer group, and 148 healthy volunteers who referred for physical examination were selected as the control group. Fluorescence in situ hybridisation was used to detect the expression of lncRNA HOTAIR in the cancerous tissues and adjacent tissues of lung cancer patients; the immunofluorescence method was used to detect the serum NSE, CEA and CYFRA21-1 levels of the two groups of testers. Correlation analysis was used to evaluate any relation between cancer staging and markers. In addition, ROC curve analysis was used to estimate sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

The expression of lncRNA HOTAIR in lung cancer tissues was higher than control or surrounding tissue (p < 0.05). Also, high levels of NSE, CEA and CYFRA21-1 were observed in lung cancer group (p < 0.05). In both N and T stage, the expression of lncRNA HOTAIR combined with NSE, CEA and CYFRA21-1 levels increased with the increase in the number of stages (p < 0.05). The results of single factor analysis showed that NSE, CEA, CYFRA21-1 and lncRNA HOTAIR all have appropriate diagnostic value for detecting lung cancer (specificity of 92.6, 91.5, 90.6, 86.9%, respectively and the sensitivity of 61.3, 62.9, 55.4, 52.3%, respectively).

CONCLUSION

LncRNA HOTAIR is a novel diagnostic test with high diagnostic value for detecting of pathological staging of NSCLC; however, the diagnostic accuracy of lncRNA HOTAIR is not higher than other tumour biomarkers.

The analysis of tumor-infiltrating immune cell and ceRNA networks in laryngeal squamous cell carcinoma

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is one of the most common forms of head and neck cancers. However, few studies have focused on the correlation between competing endogenous RNA (ceRNAs) and immune cells in LSCC.

METHODS

RNAseq expression of LSCC and adjacent tissues were downloaded from The Cancer Genome Atlas to establish a ceRNA network. The key gene in ceRNA was screened by the cox regression analysis to establish a prognostic risk assessment model. The CIBERSORT algorithm was then used to screen important tumor-infiltrating cells related to LSCC. Finally, co-expression analysis was applied to explore the relationship between key genes in the ceRNA network and tumor-infiltrating cells. The external datasets were used to validate critical biomarkers.

RESULTS

We constructed a prognostic risk assessment model of key genes in the ceRNA network. As it turned out, Kaplan-Meier survival analysis showed significant differences in overall survival rates between high-risk and low-risk groups (P < .001). The survival rate of the high-risk group was drastically lower than that of the low-risk group, and the AUC of 1 year, 3 years, and 5 years were all above 0.7. In addition, some immune infiltrating cells were also found to be related to LSCC. In the co-expression analysis, there is a negative correlation between plasma cells and TUBB3 (r = -0.33, P = .0013). External dataset validation also supports this result.

CONCLUSION

In this study, we found that some key genes (SLC35C1, CLDN23, HOXB7, STC2, TMEM158, TNFRSF4, TUBB3) and immune cells (plasma cells) may correspond to the prognosis of LSCC.

Abnormal expression of lncRNA CASC9 in pneumonia children with respiratory failure and its feasible value for the clinical diagnosis of patients

lncRNA CASC9 expression was involved in a variety of diseases and exerted a protective role against inflammation and sepsis-induced injury. However, the role of CASC9 in severe pneumonia remains unclear. This study aimed to explore the potential diagnostic role of lncRNA CASC9 in severe pneumonia. The CASC9 expression levels were measured by RT-qPCR. The receiver operating characteristic curve (ROC) was conducted to evaluate the clinical diagnostic value of CASC9 in severe pneumonia. LPS-induced human lung fibroblast MRC-5 was used to establish the pneumonia model and then transfected with CASC9 overexpression vectors to evaluate the influence of CASC9 on cell viability and apoptosis. The inflammatory cytokines IL-1β, TNF-α, IL-6 levels were detected using a commercial enzyme-linked immunosorbent assay (ELISA). Pearson correlation analysis was used to explore the correlation between CASC9 expression and clinical data. The relative expression of CASC9 was downregulated in serum samples of severe pneumonia patients. The low expression of CASC9 in severe pneumonia was negatively correlated with several clinical data. The CASC9 had the relatively high area under ROC curve (AUC) values for distinguishing severe pneumonia from pneumonia children and healthy control. The elevated expression of CASC9 accelerated cell viability and diminished apoptosis in LPS-induced MRC-5 cells. The CASC9 expression was decreased in serum samples of severe pneumonia, and upregulation of CASC9 facilitated LPS-induced cell viability and inhibited apoptosis. In summary, CASC9 might be a diagnostic predictor and might act as a crucial regulatory roles in the progression of severe pneumonia.

Identification of novel key regulatory lncRNAs in gastric adenocarcinoma

Background

Stomach adenocarcinoma (STAD) is one of the most common and deadly cancers worldwide. Recent evidence has demonstrated that dysregulation of long noncoding RNAs (lncRNA) is associated with different hallmarks of cancer. lncRNAs also were suggested as novel promising biomarkers for cancer diagnosis and prognosis. Despite these previous investigations, the expression pattern, diagnostic role, and hallmark association of lncRNAs in STAD remain unclear.

Results

In this study, The STAD lncRNA-mRNA network was constructed based on RNAs that differentially expressed among tumor and normal samples and had a strong expression correlation with others. The high degree nodes of the network were associated with overall survival. In addition, we found that the hubs’ regulatory roles have previously been confirmed in different types of cancers by literature. For example, the HCG22 hub inhibited cell proliferation and invasion and induced apoptosis in oral squamous cell carcinoma (OSCC) cells. The levels of PCNA, Vimentin, and Bcl2 were decreased and E-cadherin and Bax expression was elevated in OSCC cells after HCG22 overexpression. Additionally, HCG22 overexpression inhibited the Akt, mTOR, and Wnt/β-catenin pathways.

Then lncRNAs were mapped to their related GO terms and cancer hallmarks. Based on these mappings, we predict the hallmarks that might be associated with each lncRNA. Finally, the literature review confirmed our prediction.

Among the 20 lncRNAs of the STAD network, 11 lncRNAs (LINC02560, SOX21-AS1, C5orf66-AS1, HCG22, PGM5-AS1, NALT1, ENSG00000241224.2, TINCR, MIR205HG, HNF4A-AS1, ENSG00000262756) demonstrated expression correlation with overall survival (OS). Based on expression analysis, survival analysis, hallmark associations, and literature review, LINC02560, SOX21-AS1, C5orf66-AS1, HCG22, PGM5-AS1, NALT1, ENSG00000241224.2, TINCR, MIR205HG, HNF4A-AS1 plays a regulatory role in STAD. For example, our prediction of association between C5orf66-AS1 expression dysregulation and “sustaining proliferative signal” and “Activating invasion and metastasis” has been confirmed in STAD, OSCC and cervical cancer. Finally, we developed a lncRNA signature with SOX21-AS1 and LINC02560, which classified patients into high and low-risk subgroups with significantly different survival outcomes. The mortality rate of the high-risk patients was significantly higher compared to the low-risk patients (28/1% vs 60.13).

Conclusion

These findings help in designing more precise and detailed experimental studies to find STAD biomarkers and therapeutic targets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08578-6.

The association of long non-coding RNA in the prognosis of oral squamous cell carcinoma

BACKGROUND

Oral cancer is considered one of the most prevalent cancers in India. This is mainly because India suffers from high usage of tobacco, which is one of the main causative agents of oral cancer, and lacks proper health and sexual hygiene in rural areas.

DISCUSSION

Non-coding RNAs are reported to be involved in the various mechanism and causality of cancer. Numerous reports have identified viable prospects connecting non-coding RNA (ncRNA) with cancer. Specific ncRNAs like long non-coding RNA or lncRNAs are recently being prioritized as potential associations in the cause of cancer.

CONCLUSION

This review aims at presenting a concise perspective on the basics and the recent advancements of the lncRNA research pertaining specifically to oral cancer, its recurrence, and the future possibilities of knowledge it might possess.

ETV5-mediated upregulation of lncRNA CTBP1-DT as a ceRNA facilitates HGSOC progression by regulating miR-188-5p/MAP3K3 axis

High-grade serous ovarian cancer (HGSOC) is a common and lethal cancer of the female reproductive system. Long non-coding RNAs (lncRNAs) are aberrantly expressed in various cancers and play crucial roles in tumour progression. However, their function and molecular mechanism in HGSOC remain largely unknown. Based on public databases and bioinformatics analyses, the overexpression of lncRNA CTBP1-DT in HGSOC tissues was detected and validated in a cohort of HGSOC tissues. High expression of lncRNA CTBP1-DT was associated with poor prognosis and was an independent risk factor for survival. Overexpression of lncRNA CTBP1-DT promoted malignant biological behaviour of HGSOC cells, whereas its depletion induced growth arrest of HGSOC cells by vitro and in vivo assays. Mechanistically, lncRNA CTBP1-DT could competitively bind to miR-188-5p to protect MAP3K3 from degradation. Moreover, our results revealed that ETV5 could specifically interact with the promoter of lncRNA CTBP1-DT and activate its transcription. Collectively, these results reveal a novel ETV5/lncRNA CTBP1-DT/miR-188-5p/MAP3K3 pathway for HGSOC progression and suggest that lncRNA CTBP1-DT might be a potential biomarker and therapeutic target for HGSOC.

Downregulation of Cell Cycle and Checkpoint Genes by Class I HDAC Inhibitors Limits Synergism with G2/M Checkpoint Inhibitor MK-1775 in Bladder Cancer Cells

Since genes encoding epigenetic regulators are often mutated or deregulated in urothelial carcinoma (UC), they represent promising therapeutic targets. Specifically, inhibition of Class-I histone deacetylase (HDAC) isoenzymes induces cell death in UC cell lines (UCC) and, in contrast to other cancer types, cell cycle arrest in G2/M. Here, we investigated whether mutations in cell cycle genes contribute to G2/M rather than G1 arrest, identified the precise point of arrest and clarified the function of individual HDAC Class-I isoenzymes. Database analyses of UC tissues and cell lines revealed mutations in G1/S, but not G2/M checkpoint regulators. Using class I-specific HDAC inhibitors (HDACi) with different isoenzyme specificity (Romidepsin, Entinostat, RGFP966), cell cycle arrest was shown to occur at the G2/M transition and to depend on inhibition of HDAC1/2 rather than HDAC3. Since HDAC1/2 inhibition caused cell-type-specific downregulation of genes encoding G2/M regulators, the WEE1 inhibitor MK-1775 could not overcome G2/M checkpoint arrest and therefore did not synergize with Romidepsin inhibiting HDAC1/2. Instead, since DNA damage was induced by inhibition of HDAC1/2, but not of HDAC3, combinations between inhibitors of HDAC1/2 and of DNA repair should be attempted.

Identification novel prognostic signatures for Head and Neck Squamous Cell Carcinoma based on ceRNA network construction and immune infiltration analysis

Background: Head and neck squamous cell carcinoma (HNSCC) is a common malignancy with high mortality and morbidity worldwide, but the underlying biological mechanisms of molecules and tumor infiltrating-immune cells (TIICs) are still unknown. Methods and Results: We obtained mRNAs, lncRNAs, and miRNAs expression profiles of 546 HNSCC from The Cancer Genome Atlas (TCGA) database to develop a ceRNA network. CIBERSORT was employed to estimate the fraction of 22 types of TIICs in HNSCC. Univariate and multivariate Cox regression and lasso regression analyses were used to develop prognostic signatures. Then, two novel risk signatures were constructed respectively based on six ceRNAs (ANLN, KIT, PRKAA2, NFIA, PTX3 and has-miR-148a-3p) and three immune cells (naïve B cells, regulatory T cells and Neutrophils). Kaplan-Meier (K-M) analysis and Cox regression analysis further proved that these two signatures were significant prognostic factors independent of multiple clinicopathological characteristics. Two nomograms were built based on ceRNAs-riskScore and TIICs-riskScore that could be used to predict the prognosis of HNSCC. Co-expression analysis showed significant correlations between miR-148a-3p and naive B cells, naive B cells and plasmas cells. Conclusion: Through construction of the ceRNA network and estimation of TIICs, we established two risk signatures and their nomograms with excellent utility, which indicated the potential molecular and cellular mechanisms, and predicted the prognosis of HNSCC.

Inhibition of long non-coding RNA MALAT1 elevates microRNA-429 to suppress the progression of hypopharyngeal squamous cell carcinoma by reducing ZEB1

OBJECTIVE

Hypopharyngeal squamous cell carcinoma (HSCC) is a common type of malignant tumor. Long non-coding RNAs (lncRNAs) are known to participate in HSCC development, while the role of lncRNA MALAT1 in HSCC remains largely unknown. We aimed to explore function of the lncRNA MALAT1/miR-429/ZEB1 axis in HSCC progression.

METHODS

Levels of MALAT1, miR-429 and ZEB1 in HSCC tissues samples were assessed. The FaDu cells were respectively treated with relative sequence or plasmid of MALAT1, miR-429, or ZEB1. Then, CCK-8 assay, colony formation assay, flow cytometry and Transwell assay were used to determine the cell proliferation, apoptosis, cell cycle, migration and invasion of the cells. The PI3K/Akt/mTOR signaling pathway-related proteins, proliferation-related proteins, cell cycle-related proteins, apoptosis-related proteins, and migration-related proteins were detected using Western blot analysis. The cell growth in vivo was observed. The targeting relationships between MALAT1 and miR-429, and between miR-429 and ZEB1 were confirmed.

RESULTS

MALAT1 and ZEB1 expression in HSCC was upregulated while miR-429 expression was downregulated. Reduced MALAT1 and ZEB1, and upregulated miR-429 inactivated the PI3K/Akt/mTOR signaling pathway, suppressed in vitro viability, colony formation ability, migration and invasion, as well as cell growth in vivo, and promoted the apoptosis of FaDu cells. Downregulated miR-429 reversed the role of MALAT1 inhibition in FaDu cell growth. LncRNA MALAT1 served as a sponge of miR-429, thus regulating ZEB1 expression.

CONCLUSION

Inhibition of MALAT1 was able to elevate miR-429 to suppress the progression of HSCC via reducing ZEB1. Our research provided a potential therapeutic target for HSCC.

STAT3-Induced Upregulation of lncRNA CASC9 Promotes the Progression of Bladder Cancer by Interacting with EZH2 and Affecting the Expression of PTEN

Objective

Long non-coding RNA (lncRNA) cancer susceptibility candidate 9 (CASC9) has been reported to play a vital role in tumorigenesis. This study explored the biological role of CASC9 and its regulation mechanism in bladder cancer (BC).

Methods

Gene expression was evaluated using quantitative reverse transcription polymerase chain reaction and Western blot. The functional role of CASC9 in BC was studied using Cell Counting Kit-8, colony formation assay, scratch wound healing assay, transwell invasion assay, and xenograft tumor assay. In addition, the mechanism of CASC9 function in BC was determined using RNA immunoprecipitation assay and chromatin immunoprecipitation assay.

Results

CASC9 was upregulated in BC tissues and cell lines, and correlated with the staging and metastasis in BC. Knockdown of CASC9 inhibited the proliferation, migration, and invasion of BC cells. Similarly, silencing of CASC9 inhibited tumor growth in vivo. Signal transducer and activator of transcription 3 (STAT3) was upregulated in BC tissues and cell lines, and positively correlated with CASC9 in BC tissues. Moreover, CASC9 was shown to be regulated by STAT3 in BC cells. Furthermore, CASC9 regulated phosphatase and tensin homolog (PTEN) expression by interacting with enhancer of zeste homolog 2 (EZH2). More significantly, CASC9 silencing-mediated inhibition of BC progression was partly reversed by EZH2 overexpression or PTEN inhibition.

Conclusion

Upregulation of CASC9 induced by STAT3 promoted the progression of BC by interacting with EZH2 and affecting the expression of PTEN, representing a novel regulatory mechanism for BC progression.

Long non-coding RNA CTBP1-AS2 enhances cervical cancer progression via up-regulation of ZNF217 through sponging miR-3163

Background

Long non-coding RNAs (lncRNAs) play significant roles in tumorigenesis and can contribute to identification of novel therapeutic targets for cancers. This paper was aimed at exploring the role of CTBP1 divergent transcript (CTBP1-AS2) in cervical cancer (CC) progression.

Methods

qRT-PCR and western blot assays were used to detect relevant RNA and protein expressions. In vitro functional assays, including CCK8, EdU, TUNEL and transwell assays were applied to explore the functions of CTBP1-AS2 in CC cell proliferation, apoptosis and migration. In vivo animal study was utilized to investigate the role of CTBP1-AS2 in tumor growth. Luciferase reporter, RNA pull down and RIP assays were performed to determine the specific mechanical relationship between CTBP1-AS2, miR-3163 and ZNF217.

Results

CTBP1-AS2 was significantly overexpressed in CC cell lines. Knockdown of CTBP1-AS2 curbed cell proliferation, migration and invasion, while stimulated cell apoptosis in vitro. CTBP1-AS2 facilitated xenograft tumor growth in vivo. Cytoplasmic CTBP1-AS2 was found to be a miR-3163 sponge in CC cells. MiR-3163 inhibition abolished the anti-tumor effects of CTBP1-AS2 knockdown. Additionally, Zinc finger protein 217 (ZNF217) was identified as a direct target of miR-3163. CTBP1-AS2 acted as a miR-3163 sponge to elevate ZNF217 expression. ZNF217 up-regulation abrogated the tumor suppressing effects of CTBP1-AS2 knockdown.

Conclusion

CTBP1-AS2 regulates CC progression via sponging miR-3163 to up-regulate ZNF217.

Screening key lncRNAs with diagnostic and prognostic value for head and neck squamous cell carcinoma based on machine learning and mRNA-lncRNA co-expression network analysis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common type of cancer around the world. The aim of this study was to seek the long non-coding RNAs (lncRNAs) acting as diagnostic and prognostic biomarker of HNSCC.

METHODS

Base on TCGA dataset, the differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified between HNSCC and normal tissue. The machine learning and survival analysis were performed to estimate the potential diagnostic and prognostic value of lncRNAs for HNSCC. We also build the co-expression network and functional annotation. The expression of selected candidate mRNAs and lncRNAs were validated by Quantitative real time polymerase chain reaction (qRT-PCR).

RESULTS

A total of 3363 DEmRNAs (1822 down-regulated and 1541 up-regulated mRNAs) and 32 DElncRNAs (13 down-regulated and 19 up-regulated lncRNAs) between HNSCC and normal tissue were obtained. A total of 13 lncRNAs (IL12A.AS1, RP11.159F24.6, RP11.863P13.3, LINC00941, FOXCUT, RNF144A.AS1, RP11.218E20.3, HCG22, HAGLROS, LINC01615, RP11.351J23.1, AC024592.9 and MIR9.3HG) were defined as optimal diagnostic lncRNAs biomarkers for HNSCC. The area under curve (AUC) of the support vector machine (SVM) model, decision tree model and random forests model and were 0.983, 0.842 and 0.983, and the specificity and sensitivity of the three model were 95.5% and 96.2%, 77.3% and 97.6% and 93.2% and 97.8%, respectively. Among them, AC024592.9, LINC00941, LINC01615 and MIR9-3HG was not only an optimal diagnostic lncRNAs biomarkers, but also related to survival time. The focal adhesion, ECM-receptor interaction, pathways in cancer and cytokine-cytokine receptor interaction were four significantly enriched pathways in DEmRNAs co-expressed with the identified optimal diagnostic lncRNAs. But for most of the selected DEmRNAs and DElncRNAs, the expression was consistent with our integrated analysis results, including LINC00941, LINC01615, FOXCUT, TGA6 and MMP13.

CONCLUSION

AC024592.9, LINC00941, LINC01615 and MIR9-3HG was not only an optimal diagnostic lncRNAs biomarkers, but also were a prognostic lncRNAs biomarkers.

Long non-coding RNA CASC9 promotes tumor growth and metastasis via modulating FZD6/Wnt/β-catenin signaling pathway in bladder cancer

BACKGROUND

Accumulating evidence have highlighted the importance of long noncoding RNAs (lncRNAs) in multiple cancers development and progression. Cancer susceptibility candidate 9 (CASC9) is a novel long non-coding RNA and plays important regulatory role in diverse biological processes of cancers. However, the clinical significance and molecular mechanism of CASC9 in bladder cancer is still unknown.

METHODS

Comprehensive lncRNAs profiling analysis were conducted to identify lncRNAs profile alterations and uncover valuable lncRNA candidates for bladder cancer. The expression level of CASC9 was determined in a total of 106 patients with bladder cancer. Loss-of-function experiments were performed to identify the functions of CASC9 in tumor growth and metastasis of bladder cancer in vitro and in vivo. Bioinformatics analysis and further experiments were performed to explore the molecular mechanisms underlying the functions of CASC9.

RESULTS

This study found that CASC9 expression was markedly upregulated in bladder cancer and related to histological grade, TNM stage and prognosis. Knockdown of CASC9 inhibited tumor growth and metastasis of bladder cancer in vitro and in vivo. Mechanistically, we found that CASC9 functions as a miRNA sponge to positively regulate FZD6 expression and subsequently activates Wnt/β-catenin signaling pathway, thus playing an oncogenic role in bladder cancer pathogenesis.

CONCLUSION

In summary, lncRNA CASC9 plays a critical regulatory role in bladder cancer. The CASC9/miR-497-5p/ FZD6 axis provides insights for regulatory mechanism of bladder cancer, and new strategies for clinical practice.

Exosomal Long Non-Coding RNAs in Lung Diseases

Within the non-coding genome landscape, long non-coding RNAs (lncRNAs) and their secretion within exosomes are a window that could further explain the regulation, the sustaining, and the spread of lung diseases. We present here a compilation of the current knowledge on lncRNAs commonly found in Chronic Obstructive Pulmonary Disease (COPD), asthma, Idiopathic Pulmonary Fibrosis (IPF), or lung cancers. We built interaction networks describing the mechanisms of action for COPD, asthma, and IPF, as well as private networks for H19, MALAT1, MEG3, FENDRR, CDKN2B-AS1, TUG1, HOTAIR, and GAS5 lncRNAs in lung cancers. We identified five signaling pathways targeted by these eight lncRNAs over the lung diseases mentioned above. These lncRNAs were involved in ten treatment resistances in lung cancers, with HOTAIR being itself described in seven resistances. Besides, five of them were previously described as promising biomarkers for the diagnosis and prognosis of asthma, COPD, and lung cancers. Additionally, we describe the exosomal-based studies on H19, MALAT1, HOTAIR, GAS5, UCA1, lnc-MMP2-2, GAPLINC, TBILA, AGAP2-AS1, and SOX2-OT. This review concludes on the need for additional studies describing the lncRNA mechanisms of action and confirming their potential as biomarkers, as well as their involvement in resistance to treatment, especially in non-cancerous lung diseases.

Long Noncoding RNA MNX1 antisense RNA 1 Exerts Oncogenic Functions in Bladder Cancer by Regulating miR-218-5p/RAB1A Axis

LncRNA MNX1 antisense RNA 1 (MNX1-AS1) is significantly overexpressed in patients with bladder cancer, suggesting that it might be associated with bladder cancer. However, the molecular mechanism of MNX1-AS1 in bladder cancer remained indistinct. To illustrate the role of MNX1-AS1 in bladder cancer, the gain- and loss-of-function experiments were conducted in bladder cancer cells. Reduced expression of MNX1-AS1 could suppress cell proliferation, migration, invasion, and epithelial-mesenchymal transition in bladder cancer cells, whereas overexpression of MNX1-AS1 resulted in the opposite effects. Mechanistic analysis demonstrated that miR-218-5p was a direct target of RAB1A. MNX1-AS1 could competitively bind to miR-218-5p to regulate RAB1A expression in bladder cancer cells. Furthermore, in vivo experiments revealed that reduced expression of MNX1-AS1 inhibited tumor growth and metastasis. Taken together, MNX1-AS1 functions as a sponge to miR-218-5p to modulate RAB1A expression in bladder cancer, which suggests that MNX1-AS1 might serve as a novel therapeutic target and a novel biomarker for metastasis and prognosis in bladder cancer. SIGNIFICANCE STATEMENT: Our study demonstrates that long noncoding RNA MNX1-AS1 promotes the initiation and progression of bladder cancer. MNX1-AS1 regulates RAB1A expression to promote proliferation, migration, invasion, and epithelial-mesenchymal transitions of bladder cancer cells via miR-218-5p, which contributes to the tumor growth and metastasis of bladder cancer. Collectively, these results suggest that MNX1-AS1 might serve as a potential biomarker for bladder cancer.

Epigenetic Modifications in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common human malignancy in the world, with high mortality and poor prognosis for patients. Among the risk factors are tobacco and alcohol intake, human papilloma virus, and also genetic and epigenetic modifications. Many studies show that epigenetic events play an important role in HNSCC development and progression, including DNA methylation, chromatin remodeling, histone posttranslational covalent modifications, and effects of non-coding RNA. Epigenetic modifications may influence silencing of tumor suppressor genes by promoter hypermethylation, regulate transcription by microRNAs and changes in chromatin structure, or induce genome instability through hypomethylation. Moreover, getting to better understand aberrant patterns of methylation may provide biomarkers for early detection and diagnosis, while knowledge about target genes of microRNAs may improve the therapy of HNSCC and extend overall survival. The aim of this review is to present recent studies which demonstrate the role of epigenetic regulation in the development of HNSCC.

GLUT-1 participates in the promotion of LncRNA CASC9 in proliferation and metastasis of laryngeal carcinoma cells

Increasing evidence indicates that long non-coding RNA (lncRNA) may play important roles in tumorigenesis. Increased lncRNA CASC9 occurs in laryngeal carcinoma, which accounts for 20% of all head and neck cancers, but its role in this disease remains unknown. Using quantitative reverse transcriptase PCR, we found higher expression of CASC9 and GLUT-1 in laryngeal carcinoma tissues and cells, compared to adjacent tissues and cells. A correlation analysis showed a positive relationship between CASC9 and GLUT-1 expression in laryngeal carcinoma tissues. An MTT assay of TU212 and Hep-2 cells showed increased cell proliferation after transfection with overexpressed CASC9 and decreased cell proliferation after transfection with silenced CASC9. A Transwell assay showed that overexpressing CASC9 increased and silencing CASC9 decreased cell migration of TU212 and Hep-2 cells. A flow cytometry assay showed that overexpressing CASC9 reduced and silencing CASC9 increased cell apoptosis. In other words, we found that overexpressing CASC9 increased cell proliferation and cell migration and decreased apoptosis both in TU212 and Hep-2 cells, whereas silencing CASC9 had the opposite effects. Moreover, overexpression vector of GLUT-1 was used to investigate the molecular mechanism of CASC9 in laryngeal carcinoma. The results showed that transfection with an overexpressed GLUT-1vector reversed the effects of silencing CASC9 on proliferation, migration, and apoptosis in TU212 and Hep-2 cells. In conclusion, our study of laryngeal carcinoma found that CASC9 was positively correlated with GLUT-1 expression and that CASC9 may promote proliferation and metastasis of laryngeal carcinoma cells by regulating GLUT-1.