LncRNA ATB promotes the proliferation and metastasis of lung cancer via activation of the p38 signaling pathway

The p38 MAPK/snail signaling axis participates in cadmium-induced lung cancer cell migration and invasiveness

To determine that p38 MAPK activation contributes to the migration and invasion of lung cancer cells caused by cadmium (Cd). A549 lung cancer cell migration and invasion were assessed using a transwell plate system, and the role of p38 was determined by knocking down p38 activity with two different inhibitors of p38. The activity of p38 was measured by western blot analysis using phospho-specific p38 antibodies and normalized to blots using antibodies directed to total p38 proteins. Snail transcripts were measured using qRT-PCR. The inhibition of p38 blocked Cd-induced migration and invasion, which correlated with an increased activation of p38 as a function of dose and time. Furthermore, Cd-induced activation of p38 MAPK controlled the increase of snail mRNA expression. The p38 MAPK/snail signaling axis was involved in Cd-induced lung cancer cell migration and invasion.

The function of LncRNA-ATB in cancer

Cancer as a progressive and complex disease is caused by early chromosomal changes and stimulated cellular transformation. Previous studies reported that long non-coding RNAs (lncRNAs) play pivotal roles in the initiation, maintenance, and progression of cancer cells. LncRNA activated by TGF-β (ATB) has been shown to be dysregulated in different types of cancer. Aberrant expression of lncRNA-ATB plays an important role in the progression of diverse malignancies. High expression of LncRNA-ATB is associated with cancer cell growth, proliferation, metastasis, and EMT. LncRNA-ATB by targeting various signaling pathways and microRNAs (miRNAs) can trigger cancer pathogenesis. Therefore, lncRNA-ATB can be a novel target for cancer prediction and diagnosis. In this review, we will focus on the function of lncRNA-ATB in various types of human cancers.

Xiaotan Sanjie Decoction Inhibits Gastric Cancer Cell Proliferation, Migration, and Invasion through lncRNA-ATB and miR-200A

This study is aimed at exploring whether Xiaotan Sanjie decoction (XTSJ) inhibits gastric cancer (GC) proliferation and metastasis by regulating lncRNA-ATB expression. qRT-PCR and Western blot were used to analyze lncRNA-ATB and downstream-regulated genes/proteins in human GC cells. CCK8, Edu, and flow cytometry assays were used to detect the inhibitory effect of XTSJ on cell proliferation and apoptosis. Moreover, transwell and wound healing assays were used to detect the inhibitory effect of XTSJ on migration and invasion. qRT-PCR and Western blot were used to detect regulated genes and proteins levels. The HGC-27 cell line was used for follow-up analysis due to the high level of lncRNA-ATB and cell characteristics. XTSJ inhibited the proliferation and metastasis of HGC-27 in a dose-dependent manner. Further research found that XTSJ downregulated lncRNA-ATB, Vimentin, and N-cadherin, while it upregulated miR-200a and E-cadherin in a dose-dependent manner. XTSJ also upregulated Caspase 3, Caspase 9, Bax, and downregulated Bcl-2. Furthermore, XTSJ inhibited tumor growth in vivo and downregulated EMT signaling pathways. These results indicate that XTSJ may affect EMT and Bcl-2 signaling pathways by regulating lncRNA-ATB and miR-200a, thus inhibiting proliferation, migration, and invasion of HGC-27 cells. Therefore, XTSJ may be an effective treatment for the high levels of lncRNA-ATB in GC.

The Emerging role of EMT-related lncRNAs in therapy resistance and their application as biomarkers

Cancer is the world's second largest cause of death. The most common cancer treatments are surgery, radiation therapy, and chemotherapy. Drug resistance, epithelial-to-mesenchymal transition (EMT), and metastasis are all pressing issues in cancer therapy today. Increasing evidence showed that drug-resistant and EMT are co-related with each other. Indeed, drug-resistant cancer cells possess enhanced EMT and invasive ability. Recent researches have demonstrated lncRNAs (long noncoding RNAs) are noncoding transcripts, which play an important role in the regulation of EMT, metastasis, and drug resistance in different cancers. However, the relationships among lncRNAs, EMT, and drug resistance are still unclear. These effects could be exerted via several signaling pathways such as TGF-β, PI3K-AKT, and Wnt/β-catenin. Identifying the crucial regulatory roles of lncRNAs in these pathways and processes leads to the development of novel targeted therapies. We review the key aspects of lncRNAs associated with EMT and therapy resistance. We focus on the crosstalk between lncRNAs and molecular signaling pathways affecting EMT and drug resistance. Moreover, each of the mentioned lncRNAs could be used as a potential diagnostic, prognostic, and therapeutic biomarker for cancer. Although, there are still many challenges to investigate lncRNAs for clinical applications.

Missing lnc(RNAs) in Alzheimer's Disease?

With the ongoing demographic shift towards increasingly elderly populations, it is estimated that approximately 150 million people will live with Alzheimer's disease (AD) by 2050. By then, AD will be one of the most burdensome diseases of this and potentially next centuries. Although its exact etiology remains elusive, both environmental and genetic factors play crucial roles in the mechanisms underlying AD neuropathology. Genome-wide association studies (GWAS) identified genetic variants associated with AD susceptibility in more than 40 different genomic loci. Most of these disease-associated variants reside in non-coding regions of the genome. In recent years, it has become clear that functionally active transcripts arise from these non-coding loci. One type of non-coding transcript, referred to as long non-coding RNAs (lncRNAs), gained significant attention due to their multiple roles in neurodevelopment, brain homeostasis, aging, and their dysregulation or dysfunction in neurological diseases including in AD. Here, we will summarize the current knowledge regarding genetic variations, expression profiles, as well as potential functions, diagnostic or therapeutic roles of lncRNAs in AD. We postulate that lncRNAs may represent the missing link in AD pathology and that unraveling their role may open avenues to better AD treatments.

Long non-coding RNA ATB is associated with metastases and promotes cell invasion in colorectal cancer via sponging miR-141-3p

Long non-coding RNAs (lncRNAs) serve crucial roles in cancer development and progression. lncRNA-activated by transforming growth factor-β (lncRNA-ATB) mediates cell proliferation. However, the association between lncRNA-ATB and human colorectal cancer (CRC) is not completely understood. Therefore, the present study aimed to investigate the role of lncRNA-ATB in CRC, as well as the underlying mechanism. 50 pairs of tumor tissues and adjacent normal tissues from patients with primary CRC were collected. The expression of lncRNA-ATB and microRNA (miR)-141-3p in CRC tissues, adjacent normal tissues and cell lines was detected using reverse transcription-quantitative PCR. CCK-8, colony formation, Transwell, western blot, dual luciferase reporter gene, RNA immunoprecipitation and immunohistochemistry staining assays were conducted to assess the biological function of lncRNA-ATB and miR-141-3p in CRC progression. lncRNA-ATB was upregulated in CRC tissues and cell lines compared with healthy tissues and cells, respectively. Moreover, high expression of lncRNA-ATB was significantly associated with advanced TNM stage and metastasis in CRC. In addition, the results indicated that lncRNA-ATB expression predicted the prognosis and overall survival of patients with CRC. Compared with small interfering RNA-negative control, lncRNA-ATB knockdown inhibited CRC cell proliferation, migration and invasion, whereas, compared with vector, lncRNA-ATB overexpression promoted CRC cell proliferation, migration and invasion. Furthermore, the in vivo experiment suggested that lncRNA-ATB knockdown inhibited tumor growth. The results also indicated that lncRNA-ATB may contribute to CRC progression via binding to tumor suppressor microRNA-141-3p. Collectively, the present study suggested a crucial role of lncRNA-ATB in CRC tumorigenesis, suggesting that lncRNA-ATB may serve as an important marker for the diagnosis and development of CRC.

An update on long intergenic noncoding RNA p21: a regulatory molecule with various significant functions in cancer

Long intergenic noncoding RNA p21 was mapped on the human chromosome 6p21.2. Accordingly, it was firstly described by promoting the p53-dependent apoptosis in the mouse. Also, it is a new lncRNA playing some vital roles in the cell cycle, apoptosis, cell proliferation, tumorigenesis, invasion, metastasis, and angiogenesis. In this regard, it was shown that, lincRNA-p21 regulates these biological processes involved in carcinogenesis through various signaling pathways including Notch signaling, JAK2/STAT3, and AKT/mTOR pathways. Another mechanism by that lincRNA-p21 can affect these processes is a cross-talk with different miRNAs. In vitro and in vivo studies revealed dysregulation of lincRNA-p21 in various human cancers. In addition, emerging evidence demonstrated that, lincRNA-p21 can be considered as a potential prognostic and therapeutic biomarker in cancers. Also, lincRNA-p21 enhances the response to radiotherapy for colorectal cancer. However, the molecular mechanisms of lincRNA-p21 in carcinogenesis have not been fully elucidated so far. So, this review summarizes the function of lincRNA-p21, as a tumor suppressor factor in different biological processes implicated in cancers.

LncRNA-ATB Promotes Cisplatin Resistance in Lung Adenocarcinoma Cells by Targeting the miR-200a/β-Catenin Pathway

Introduction

Lung adenocarcinoma (LUAD), which is associated with high morbidity and mortality, is prone to cisplatin resistance, resulting in poor patient prognosis. Long non-coding RNAs (lncRNAs) have complex biological functions in a variety of tumors. Elucidating the underlying molecular mechanisms between lncRNA and cisplatin resistance in LUAD is expected to enable identification of new targets for drug development.

Methods

Cell proliferation was measured by CCK-8 assay and cell apoptosis was detected using flow cytometry analysis. Luciferase reporter assay was conducted to determine the interaction between lncRNA and MicroRNA. Gene expression was evaluated by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction and Western blot analysis.

Results

Long non-coding RNA activated by TGF-β (lncRNA-ATB) was shown to be significantly up-regulated in A549 cells resistant to cisplatin/cis-dichlorodiammineplatinum (II) (cis-DDP) (A549/CDDP cells), compared with corresponding levels in parental A549 cells. Overexpression of lncRNA-ATB significantly elevated cisplatin resistance in LUAD cell lines (A549 and H1975 cells), and this was associated with activation of apoptosis-related genes. Conversely, silencing of lncRNA-ATB decreased cisplatin resistance in LUAD cells. Mechanistically, lncRNA-ATB increased expression of β-catenin by directly binding to MicroRNA-200a (miR-200a), thereby promoting cell survival and cisplatin resistance. Transfection with a miR-200a mimic or treatment with the β-catenin downstream pathway inhibitor IWR-1 could reverse the phenotypes induced by lncRNA-ATB overexpression.

Conclusion

In summary, this study revealed that lncRNA-ATB is dramatically up-regulated in cisplatin-resistant LUAD cell lines, and that lncRNA-ATB facilitates cell survival by targeting the miR-200a/β-catenin pathway in these cells.

lncRNA-ATB promotes stemness maintenance in colorectal cancer by regulating transcriptional activity of the β-catenin pathway

Long non-coding RNA activated by transforming growth factor-β (ATB) was recently reported to be involved in a wide range of physiological and pathological processes. However, the role of ATB in colorectal cancer (CRC) stemness remains unclear. In the present study, the functional role of ATB in maintaining stemness of CRC was determined using colony formation and sphere formation assays, and xenograft models. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were performed to investigate the mechanisms underlying the effects of ATB. Knockdown of ATB impaired colony formation and sphere formation in CRC cells, accompanied by an inhibition of colon tumor growth. Further results suggested that ATB regulated the transcriptional activity of the β-catenin pathway by inhibiting β-catenin expression. In addition, the results confirmed the role of β-catenin in ATB-mediated regulation of stemness in CRC. Collectively, the results indicated that ATB is a promising therapeutic target for CRC.

Long non-coding RNAs: How to regulate the metastasis of non-small-cell lung cancer

Non–small‐cell lung cancer (NSCLC) has become the most lethal human cancer because of the high rate of metastasis. Hence, clarifying the molecular mechanism underlying NSCLC metastasis is very important to improve the prognosis of patients with NSCLC. Long non‐coding RNAs (LncRNAs) are a class of RNA molecules longer than 200 nucleotides, which can participate in diverse biological processes. About 18% of human LncRNAs were recently found to be associated with tumours. Many studies indicated that aberrant expression of LncRNAs played key roles in the progression and metastasis of NSCLC. According to the function in tumours, LncRNAs can be divided into two classes: oncogenic LncRNAs and tumour‐suppressor LncRNAs. In this review, we summarized the main molecular mechanism of LncRNAs regulating NSCLC metastasis, including three aspects: (a) LncRNAs interact with miRNAs as ceRNAs; (b) LncRNAs bind with target proteins; and (c) LncRNAs participate in the transduction of different signal pathways. Then, LncRNAs can exert their function to regulate the metastasis of NSCLC through influencing the progression of epithelial‐mesenchymal transition (EMT) and the properties of cancer stem cell (CSC). But, it is necessary to do some further research to demonstrate the LncRNAs particular regulatory mechanism of inhibiting the metastasis of NSCLC and explore new drugs targeting LncRNAs.

MiRNAs and LncRNAs: Dual Roles in TGF-β Signaling-Regulated Metastasis in Lung Cancer

Lung cancer is one of the most malignant cancers around the world, with high morbidity and mortality. Metastasis is the leading cause of lung cancer deaths and treatment failure. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs), two groups of small non-coding RNAs (nc-RNAs), are confirmed to be lung cancer oncogenes or suppressors. Transforming growth factor-β (TGF-β) critically regulates lung cancer metastasis. In this review, we summarize the dual roles of miRNAs and lncRNAs in TGF-β signaling-regulated lung cancer epithelial-mesenchymal transition (EMT), invasion, migration, stemness, and metastasis. In addition, lncRNAs, competing endogenous RNAs (ceRNAs), and circular RNAs (circRNAs) can act as miRNA sponges to suppress miRNAs, thereby mediating TGF-β signaling-regulated lung cancer invasion, migration, and metastasis. Through this review, we hope to cast light on the regulatory mechanisms of miRNAs and lncRNAs in TGF-β signaling-regulated lung cancer metastasis and provide new insights for lung cancer treatment.

lncRNA‑u50535 promotes the progression of lung cancer by activating CCL20/ERK signaling

The ligand/receptor pair C‑C motif chemokine ligand 20 (CCL20)/C‑C motif chemokine receptor 6 (CCR6) is considered to be highly activated in lung cancer and significantly accelerates lung cancer progression through activation of ERK signaling. In addition, it has been shown that long non‑coding RNA‑u50535 (lncRNA‑u50535) upregulates CCL20 expression and facilitates cancer progression in colorectal cancer (CRC). However, the effects of lncRNA‑u50535 in lung cancer progression and whether lncRNA‑u50535 regulates CCL20/CCR6/ERK signaling in lung cancer remain ill‑defined. Therefore, the aim of the present study was to investigate the effects of lncRNA‑u50535 on CCL20/CCR6/ERK signaling in lung cancer progression. The results demonstrated that lncRNA‑u50535 expression was upregulated in lung cancer tissues and cell lines compared with normal tissues and cells. Knockdown of lncRNA‑u50535 decreased lung cancer cell proliferation and migration, induced G0/G1 phase arrest and promoted cell apoptosis. Western blot and luciferase reporter gene assays demonstrated that lncRNA‑u50535 overexpression increased the translation and transcription of CCL20. In addition, knockdown of lncRNA‑u50535 decreased CCL20, CCR6 and p‑ERK levels. The effects of lncRNA‑u50535 on cell proliferation and cell apoptosis were weakened when CCL20 was silenced. Overall, the present study demonstrated that lncRNA‑u50535 may function as an oncogene in lung cancer progression by regulating CCL20/ERK signaling.

Silencing of KCNK15-AS1 inhibits lung cancer cell proliferation via upregulation of miR-202 and miR-370

Lung cancer is the most common cause of cancer-associated mortality globally. Long non-coding RNAs (lncRNAs) are transcripts with a length of >200 nucleotides, which are not translated into proteins. Growing evidence has indicated that certain lncRNAs are associated with various biological processes in cancer. However, the functions of KCNK15 and WISP2 antisense RNA 1 (KCNK15-AS1) in lung cancer carcinogenesis and progression have remained elusive. The present study indicated that KCNK15-AS1 was overexpressed in lung adenocarcinoma tissues compared with paracancerous normal tissues, and the high expression of KCNK15-AS1 was significantly associated with poor prognosis compared with the patients with low expression (P<0.001). Furthermore, the knockdown of KCNK15-AS1 was performed in A549 and H460 lung cancer cells with small interfering RNA, resulting in a significant inhibition of the proliferation, a decrease in the mRNA and protein expression of cyclin D1 (CCND1) and epidermal growth factor receptor (EGFR), in addition to the phosphorylation of protein kinase B, with a concomitant increase in the expression of microRNA (miR)-202 and miR-370 compared with negative control group. Rescue experiments demonstrated that the inhibition of miR-202 or miR-370 partially recovered the EGFR and CCND1 expression and the proliferation rates, which were reduced by KCNK15-AS1 silencing. In conclusion, these results suggested that KCNK15-AS1 functions as an oncogene via regulating the miR-202/miR-370/EGFR axis in lung cancer and may provide a potential target for lung cancer treatment.

lincRNA‑p21 inhibits the progression of non‑small cell lung cancer via targeting miR‑17‑5p

Non-small-cell lung cancer (NSCLC) is well established as one of the major subtypes of human lung cancer. NSCLC is characterized by a high incidence rate and poor patient prognosis. Previous studies have identified that long intergenic non-coding RNA (lincRNA) serves a key role in the development of tumor and malignant metastasis. However, the majority of the underlying mechanisms for lincRNA deregulation in various diseases, including cancer and diabetes, have not been completely elucidated. In the present study, the deregulation of lincRNA-p21 in NSCLC tumor tissues in comparison to adjacent healthy tissues was examined using reverse transcription-quantitative polymerase chain reaction. Furthermore, the effect of lincRNA-p21 overexpression and knockdown on different NSCLC cell lines was further investigated in vitro. The association between lincRNA-p21 expression and microRNA (miR)-17-5p level in NSCLC tumor cells was also investigated to clarify the underlying mechanism. The influence of miR-17-5p on different NSCLC cell lines A549 and PC9 were also examined in vitro using miR-17-5p mimics and inhibitors. Bioinformatics and luciferase assays were conducted to verify the direct binding sites on lincRNA-p21 for miR-17-5p. The results demonstrated that there was a significant low-expression of lincRNA-p21 in NSCLC tumor tissues, and lincRNA-p21 effectively inhibited the progression of lung cancer cells by suppressing cell proliferation and migration and promoting cell apoptosis. An evident negative association between lincRNA-p21 and miR-17-5p expression was observed, and the inhibitory effect of overexpressed lincRNA-p21 on lung cancer cells was counteracted by miR-17-5p. Bioinformatics and luciferase reporter analysis results confirmed that miR-17-5p is a direct target for lincRNA-p21. The present study provides evidence for lincRNA-p21 to inhibit the progression of NSCLC via direct targeting of a miR-17-5p associated signaling pathway.