Upregulation of long intergenic noncoding RNA 00673 promotes tumor proliferation via LSD1 interaction and repression of NCALD in non-small-cell lung cancer

Long non-coding RNAs in cutaneous melanoma: clinical perspectives

Metastatic melanoma of the skin has a high mortality despite the recent introduction of targeted therapy and immunotherapy. Long non-coding RNAs (lncRNAs) are defined as transcripts of more than 200 nucleotides in length that lack protein-coding potential. There is growing evidence that lncRNAs play an important role in gene regulation, including oncogenesis. We present 13 lncRNA genes involved in the pathogenesis of cutaneous melanoma through a variety of pathways and molecular interactions. Some of these lncRNAs are possible biomarkers or therapeutic targets for malignant melanoma.

Overexpression of lncRNA HOXA11-AS promotes cell epithelial-mesenchymal transition by repressing miR-200b in non-small cell lung cancer

Background

Recent studies have verified that long noncoding RNAs (lncRNAs) involved in many biological functions and play crucial roles in human cancers progression, the study aimed to detect the association between long non-coding RNA HOXA11-AS and epithelial–mesenchymal transition (EMT) process in non-small cell lung cancer (NSCLC).

Methods

The lncRNA HOXA11-AS expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) assays in 78 paired of tumor tissue and adjacent normal tissue samples in NSCLC patients. Kaplan–Meier survival curves and log-rank test was used to examine the association between lncRNA HOXA11-AS expression and the over survival time in NSCLC patients. Transwell invasion assay was performed to detect the cell invasion ability. QRT-PCR and western-blot analysis detected the mRNA and protein expression of EMT related transcription factors ZEB1/ZEB2, Snail1/2 and EMT marker E-cadherin and N-cadherin in NSCLC cells. RIP and Chromatin immunoprecipitation assays were performed to analyze the association between lncRNA HOXA11-AS and miR-200b expression in NSCLC cells.

Results

The lncRNA HOXA11-AS expression levels were significantly higher in NSCLC tissues compared with adjacent normal tissues and higher HOXA11-AS expression levels had a poor prognosis in NSCLC patients. Furthermore, knockdown of lncRNA HOXA11-AS in A549 and H1299 cells dramatically inhibited cell invasive abilities. Besides, the transcription levels and protein levels of EMT related transcription factors ZEB1/ZEB2, Snail1/2, and EMT maker N-cadherin were down-regulated after lncRNA HOXA11-AS was knocked down, but the mRNA and protein expression levels of EMT maker E-cadherin was increasing in A549 and H1299 cells. The mechanistic findings showed demonstrated that HOXA11-AS interacted with EZH2 and DNMT1 and recruited them to the miR-200b promoter regions to repress miR-200b expression in NSCLC cells, which promoted cell EMT in NSCLC.

Conclusions

Our results showed that up-regulation of lncRNA HOXA11-AS predicted a poor prognosis and lncRNA HOXA11-AS promoted cell epithelial–mesenchymal transition (EMT) by inhibiting miR-200b expression in NSCLC.

The histone demethylase lysine-specific demethylase-1-mediated epigenetic silence of KLF2 contributes to gastric cancer cell proliferation, migration, and invasion

Gastric cancer is one of the most common malignancies and leading causes of cancer-related death worldwide. An increasing number of evidence has revealed that gastric tumorigenesis is a multistage pathological state, and epigenetic alterations are considered to play critical roles in the etiology of gastric cancer. Lysine-specific demethylase-1, a histone demethylase, has been linked to malignancy in several human cancers and considered to epigenetically regulate many tumor suppressor genes during tumorigenesis and cancer progression. However, its role and underlying targets in gastric cancer are still unclear. In this study, we detected the lysine-specific demethylase-1 expression level in gastric cancer tissues and cell lines and investigated the function and mechanism of lysine-specific demethylase-1 in the gastric cancer. The in vitro analysis shows that knockdown of lysine-specific demethylase-1 significantly inhibits gastric cancer cell proliferation, migration, and invasion and induces cell cycle G1 phase arrest and cell apoptosis. In vivo assays determine that lysine-specific demethylase-1 downregulation represses gastric cancer cell tumorigenesis. Mechanistic investigation reveals that tumor suppressor KLF2 is a key downstream target of lysine-specific demethylase-1 in gastric cancer. These findings indicate that lysine-specific demethylase-1 is an important oncogene in gastric cancer, and lysine-specific demethylase-1-mediated epigenetic repression of KLF2 plays a critical role in gastric cancer development and progression, which supports lysine-specific demethylase-1 as a potential therapeutic target in this disease.

Long Noncoding RNA LINC00673 Is Activated by SP1 and Exerts Oncogenic Properties by Interacting with LSD1 and EZH2 in Gastric Cancer

Long noncoding RNAs (lncRNAs) have emerged as important regulators in a variety of human diseases, including cancers. However, the biological function of these molecules and the mechanisms responsible for their alteration in gastric cancer (GC) are not fully understood. In this study, we found that lncRNA LINC00673 is significantly upregulated in gastric cancer. Knockdown of LINC00673 inhibited cell proliferation and invasion and induced cell apoptosis, whereas LINC00673 overexpression had the opposite effect. Online transcription factor binding site prediction analysis showed that there are SP1 binding sites in the LINC00673 promoter region. Next, luciferase reporter and chromatin immunoprecipitation (ChIP) assays provided evidence that SP1 could bind directly to the LINC00673 promoter region and activate its transcription. Moreover, mechanistic investigation showed that CADM4, KLF2, and LATS2 might be the underlying targets of LINC00673 in GC cells, and RNA immunoprecipitation, RNA pull-down, and ChIP assays showed that LINC00673 can interact with EZH2 and LSD1, thereby repressing KLF2 and LATS2 expression. Taken together, these findings show that SP1-activated LINC00673 exerts an oncogenic function that promotes GC development and progression, at least in part, by functioning as a scaffold for LSD1 and EZH2 and repressing KLF2 and LATS2 expression.

Knockdown of Long Noncoding RNA uc.338 by siRNA Inhibits Cellular Migration and Invasion in Human Lung Cancer Cells

Lung cancer remains a critical health concern worldwide. Long noncoding RNAs with ultraconserved elements have recently been implicated in human tumorigenesis. The present study investigated the role of ultraconserved element 338 (uc.338) in the regulation of cell proliferation and metastasis in human lung cancer. Our data showed that the expression of uc.338 in lung cancer was remarkably increased in vivo and in vitro. Depletion of uc.338 with specific siRNA interference retarded the cell proliferative rate in lung cancer cell lines NCI-H929 and H1688. Furthermore, knockdown of uc.338 caused cell cycle arrest in the G₀/G₁ phase in both cell lines. Transwell assays showed that inhibition of uc.338 notably decreased migration and invasion in NCI-H929 and H1688 cells. Moreover, uc.338 depletion decreased the expression of cyclin B1, Cdc25C, Snail, vimentin, and N-cadherin while increasing the protein level of E-cadherin, shown with Western blot analysis. These results suggested the pro-oncogenic potential of uc.338 in lung cancer, which might provide novel clues for the diagnosis and treatment of lung cancer in the clinic.

Long non-coding RNA 00312 regulated by HOXA5 inhibits tumour proliferation and promotes apoptosis in Non-small cell lung cancer

Non‐small cell lung cancer (NSCLC) is the most prevalent type of lung cancer. The abnormal expression of many long non‐coding RNAs (lncRNAs) has been reported involved in the progression of various tumours, which can be used as diagnostic indicators or antitumour targets. Here, we found that the long non‐coding RNA 00312 was down‐regulated in paired NSCLC tissues and correlated with poor clinical outcome; decreased linc00312 expression in NSCLC was associated with larger and later stage tumours. Functional experiments showed that linc00312 could inhibit cell proliferation and promote apoptosis in vitro and in vivo. Furthermore, we found that HOXA5 could bind in the promoter of linc00312 and up‐regulated the expression of it. Moreover, linc00312 was down‐regulated in the plasma of NSCLC patients compared with that of healthy volunteers or other pulmonary diseases patients. Taken together, our findings indicated that linc00312 could be a novel diagnosis biomarker and a promising therapeutic target for NSCLC.

Long intergenic non-coding RNA 00152 promotes lung adenocarcinoma proliferation via interacting with EZH2 and repressing IL24 expression

BACKGROUND

Numerous studies have shown that long non-coding RNAs (lncRNAs) behave as a novel class of transcript during multiple cancer processes, such as cell proliferation, apoptosis, migration, and invasion. LINC00152 is located on chromosome 2p11.2, and has a transcript length of 828 nucleotides. The biological role of LINC00152 in LAD(lung adenocarcinoma) remains unknown.

METHODS

Quantitative reverse transcription PCR(qRT-PCR) was used to detect LINC00152 expression in 60 human LAD tissues and paired normal tissues. In vitro and in vivo studies showed the biological function of LINC00152 in tumour progression. RNA transcriptome sequencing technology was performed to identify the downstream suppressor IL24(interleukin 24) which was further examined by qRT-PCR, western bolt and rescue experiments. RNA immunoprecipitation (RIP), RNA pulldown, and Chromatin immunoprecipitation (ChIP) assays were carried out to reveal the interaction between LINC00152, EZH2 and IL24.

RESULTS

LINC00152 expression was upregulated in 60 human LAD tissues and paired normal tissues. High levels of LINC00152 expression were correlated with advanced TNM stage, larger tumor size, and lymph node metastasis, as well as shorter survival time. Silencing of LINC00152 suppressed cell growth and induced cell apoptosis. LINC00152 knockdown altered the expression of many downstream genes, including IL24. LINC00152 could interact with EZH2 and inhibit IL24 transcription. Moreover, the ectopic expression of IL24 repressed cell proliferation and partly reversed LINC00152 overexpression-induced promotion of cell growth in LAD.

CONCLUSIONS

Our study reveals an oncogenic role for LINC00152 in LAD tumorigenesis, suggesting that it could be used as a therapeutic target in LAD treatment.

Long non-coding RNAs in anti-cancer drug resistance

Chemotherapy is one of the basic treatments for cancers; however, drug resistance is mainly responsible for the failure of clinical treatment. The mechanism of drug resistance is complicated because of interaction among various factors including drug efflux, DNA damage repair, apoptosis and targets mutation. Long non-coding RNAs (lncRNAs) have been a focus of research in the field of bioscience, and the latest studies have revealed that lncRNAs play essential roles in drug resistance in breast cancer, gastric cancer and lung cancer, et al. Dysregulation of multiple targets and pathways by lncRNAs results in the occurrence of chemoresistance. In this review, we will discuss the mechanisms underlying lncRNA-mediated resistance to chemotherapy and the therapeutic potential of lncRNAs in future cancer treatment.

Integrated analysis of long non-coding RNA‑associated ceRNA network reveals potential lncRNA biomarkers in human lung adenocarcinoma

Accumulating evidence has highlighted the important roles of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) in tumor biology. However, the roles of cancer specific lncRNAs in lncRNA-related ceRNA network of lung adenocarcinoma (LUAD) are still unclear. In the present study, the 465 RNA sequencing profiles in LUAD patients were obtained from the cancer genome atlas (TCGA) database, which provides large sample RNA sequencing data free of charge, and 41 cancer specific lncRNAs, 25 miRNAs and 1053 mRNAs (fold change >2, p<0.05) were identified. Then, the lncRNA-miRNA-mRNA ceRNA network of LUAD was constructed with 29 key lncRNAs, 24 miRNAs and 72 mRNAs. Subsequently, we selected these 29 key lncRNAs to analyze their correlation with clinical features, and 21 of them were aberrantly expressed with tumor pathological stage, TNM staging system, lymph node metastasis and patient outcome assessment, respectively. Furthermore, there were 5 lncRNAs (BCRP3, LINC00472, CHIAP2, BMS1P20 and UNQ6494) positively correlated with overall survival (OS, log-rank p<0.05). Finally, 7 cancer specific lncRNAs were randomly selected to verify the expression in 53 newly diagnosed LUAD patients using qRT-PCR. The expression results between TCGA and qRT-PCR were 100% in agreement. The correlation between AFAP1-AS1 and LINC00472 and clinical features were also confirmed. Thus, our results showed the lncRNA expression profiles and we constructed an lncRNA-miRNA-mRNA ceRNA network in LUAD. The present study provides novel insight for better understanding of lncRNA-related ceRNA network in LUAD and facilitates the identification of potential biomarkers for diagnosis and prognosis.

The lncRNA SLNCR1 Mediates Melanoma Invasion through a Conserved SRA1-like Region

Long non-coding RNAs (lncRNAs) have been implicated in numerous physiological processes and diseases, most notably cancers. However, little is known about the mechanism of many functional lncRNAs. We identified an abundantly expressed lncRNA associated with decreased melanoma patient survival. Increased expression of this lncRNA, SLNCR1, mediates melanoma invasion through a highly conserved sequence similar to that of the lncRNA SRA1. Using a sensitive technique we term RATA (RNA-associated transcription factor array), we show that the brain-specific homeobox protein 3a (Brn3a) and the androgen receptor (AR) bind within and adjacent to SLNCR1's conserved region, respectively. SLNCR1, AR, and Brn3a are specifically required for transcriptional activation of matrix metalloproteinase 9 (MMP9) and increased melanoma invasion. Our observations directly link AR to melanoma invasion, possibly explaining why males experience more melanoma metastases and have an overall lower survival in comparison to females.