LncRNA LUADT1 sponges miR-15a-3p to upregulate Twist1 in small cell lung cancer

LncRNAs in non-small cell lung cancer: novel diagnostic and prognostic biomarkers

Non-small cell lung cancer (NSCLC) is one of the main causes of cancer-related death worldwide, with a serious impact on human health and life. The identification of NSCLC at an early stage is a formidable task that frequently culminates in a belated diagnosis. LncRNA is a kind of noncoding RNA with limited protein-coding capacity, and its expression is out of balance in many cancers, especially NSCLC. A large number of studies have reported that lncRNA acts a vital role in regulating angiogenesis, invasion, metastasis, and the proliferation and apoptosis of tumor cells, affecting the occurrence and development of NSCLC. Abundant evidence demonstrates that lncRNAs may serve as potential biomarkers for NSCLC diagnosis and prognosis. In this review, we summarize the latest progress in characterizing the functional mechanism of lncRNAs involved in the development of NSCLC and further discuss the role of lncRNAs in NSCLC therapy and chemotherapy resistance. We also discuss the advantages, limitations, and challenges of using lncRNAs as diagnostic or prognostic biomarkers in the management of NSCLC.

Analysis of two-gene signatures and related drugs in small-cell lung cancer by bioinformatics

Small-cell lung cancer (SCLC) has a poor prognosis and can be diagnosed with systemic metastases. Nevertheless, the molecular mechanisms underlying the development of SCLC are unclear, requiring further investigation. The current research aims to identify relevant biomarkers and available drugs to treat SCLC. The bioinformatics analysis comprised three Gene Expression Omnibus datasets (including GSE2149507, GSE6044, and GSE30219). Using the limma R package, we discovered differentially expressed genes (DEGs) in the current work. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were made by adopting the DAVID website. The DEG protein-protein interaction network was built based on the Search Tool for the Retrieval of Interacting Genes/Proteins website and visualized using the CytoHubba plugin in Cytoscape, aiming to screen the top ten hub genes. Quantitative real-time polymerase chain reaction was adopted for verifying the level of the top ten hub genes. Finally, the potential drugs were screened and identified using the QuartataWeb database. Totally 195 upregulated and 167 downregulated DEGs were determined. The ten hub genes were NCAPG, BUB1B, TOP2A, CCNA2, NUSAP1, UBE2C, AURKB, RRM2, CDK1, and KIF11. Ten FDA-approved drugs were screened. Finally, two genes and related drugs screened could be the prospective drug targets for SCLC treatment.

Long non-coding RNA MIR22HG inhibits the proliferation and migration, and promotes apoptosis by targeting microRNA-9-3p/ SOCS1 axis in small cell lung cancer cells

BACKGROUND

This study aims to determine the role of long non-coding RNA (LncRNA) MIR22HG in small cell lung cancer (SCLC), and to explore its relevant mechanism.

METHODS AND RESULTS

The expressions of genes and proteins in SCLC cells were examined applying qRT-PCR and western blot. Cell proliferation estimation was implemented utilizing cell counting kit-8 (CCK-8) and colony formation assays; the assessment of cell migration and invasion was operated employing Wound healing and Transwell; apoptosis evaluation was conducted adopting flow cytometric assay. Binding relationships was confirmed by luciferase reporter assay. Moreover, SCLC animal model was established to explore the role of MIR22HG in vivo. It was found that MIR22HG was declined and miR-9-3p was elevated in five SCLC cell lines (NCI-H446, NCI-H69, SHP-77, DMS79 and NCI-H345) in comparison with normal human bronchial epithelial cell line (NHBE). More interestingly, overexpression of MIR22HG resulted in decreased cell viability, declined colony formation, diminished capacities of cell migration and invasion in NCI-H446 and NCI-H345 cells but induced more apoptotic cells. However, these impacts were reversed by miR-9-3p upregulation. Meanwhile, MIR22HG could bind to miR-9-3p and negatively regulate its expression in SCLC. What's more, LncRNA MIR22HG overexpression was also testified to elevate SOCS1 via downregulating miR-9-3p expression. Furthermore, in vivo study further confirmed the role of MIR22HG/miR-9-3p in tumor regulation of SCLC.

CONCLUSIONS

In conclusion, MIR22HG in SCLC was found to modulate miR-9-3p level and might act as a possible biomarker for SCLC treatment.

Emerging roles of ferroptosis-related miRNAs in tumor metastasis

Ferroptosis, a novel mode of cell death dependent on iron and reactive oxygen species, has been extensively explored during malignant tumors metastasis. Ferroptosis can interact with multiple components of the tumor microenvironment to regulate metastasis. These interactions generally include the following aspects: (1) Epithelial-mesenchymal transformation, which can help cancer cells increase their sensitivity to ferroptosis while they have multiple mechanisms to fight against it; (2) Disorder of iron metabolism in cancer stem cells which maintains their stem characteristics; (3) Polarization of M0 macrophages to M2. (4) The paradoxical effects of iron metabolism and CD8 + T cells induced by ferroptosis (5) Regulation of angiogenesis. In addition, ferroptosis can be regulated by miRNAs through the reprogramming of various intracellular metabolism processes, including the regulation of the glutathione- glutathione peroxidase 4 pathway, glutamic acid/cystine transport, iron metabolism, lipid metabolism, and oxidative stress. Therefore, there are many potential interactions between ferroptosis-related miRNAs and tumor metastasis, including interaction with cancer cells and immune cells, regulating cytokines, and angiogenesis. This review focuses on the role of ferroptosis-related miRNA in tumor metastasis, aiming to help readers understand their relationship and provide a new perspective on the potential treatment strategies of malignant tumors.

The uprise of RNA biology in neuroendocrine neoplasms: altered splicing and RNA species unveil translational opportunities

Neuroendocrine neoplasms (NENs) comprise a highly heterogeneous group of tumors arising from the diffuse neuroendocrine system. NENs mainly originate in gastrointestinal, pancreatic, and pulmonary tissues, and despite being rare, show rising incidence. The molecular mechanisms underlying NEN development are still poorly understood, although recent studies are unveiling their genomic, epigenomic and transcriptomic landscapes. RNA was originally considered as an intermediary between DNA and protein. Today, compelling evidence underscores the regulatory relevance of RNA processing, while new RNA molecules emerge with key functional roles in core cell processes. Indeed, correct functioning of the interrelated complementary processes comprising RNA biology, its processing, transport, and surveillance, is essential to ensure adequate cell homeostasis, and its misfunction is related to cancer at multiple levels. This review is focused on the dysregulation of RNA biology in NENs. In particular, we survey alterations in the splicing process and available information implicating the main RNA species and processes in NENs pathology, including their role as biomarkers, and their functionality and targetability. Understanding how NENs precisely (mis)behave requires a profound knowledge at every layer of their heterogeneity, to help improve NEN management. RNA biology provides a wide spectrum of previously unexplored processes and molecules that open new avenues for NEN detection, classification and treatment. The current molecular biology era is rapidly evolving to facilitate a detailed comprehension of cancer biology and is enabling the arrival of personalized, predictive and precision medicine to rare tumors like NENs.

Non-coding genome in small cell lung cancer between theoretical view and clinical applications

Small cell lung cancer (SCLC) is a highly aggressive cancer of the neuroendocrine system, characterized by poor differentiation, rapid growth, and poor overall survival (OS) of patients. Despite the recent advances in the treatment of SCLC recently, the 2-year survival rate of patients with the cancer is only 14-15%, occasioned by the acquired resistance to drugs and serious off-target effects. In humans, the coding region is only 2% of the total genome, and 20% of that is associated with human diseases. Beyond the coding genome are RNAs, promoters, enhancers, and other intricate elements. The non-coding regulatory regions, mainly the non-coding RNAs (ncRNAs), regulate numerous biological activities including cell proliferation, metastasis, and drug resistance. As such, they are potential diagnostic or prognostic biomarkers, and also potential therapeutic targets for SCLC. Therefore, understanding how non-coding elements regulate SCLC development and progression holds significant clinical implications. Herein, we summarized the recent discoveries on the relationship between the non-coding elements including long non-coding RNAs (lncRNA), microRNAs (miRNAs), circular RNA (circRNA), enhancers as well as promotors, and the pathogenesis of SCLC and their potential clinical applications.

MEG3 LncRNA from Exosomes Released from Cancer-Associated Fibroblasts Enhances Cisplatin Chemoresistance in SCLC via a MiR-15a-5p/CCNE1 Axis

PURPOSE

Long non-coding RNAs (lncRNAs) may act as oncogenes in small-cell lung cancer (SCLC). Exosomes containing lncRNAs released from cancer-associated fibroblasts (CAF) accelerate tumorigenesis and confer chemoresistance. This study aimed to explore the action mechanism of the CAF-derived lncRNA maternally expressed gene 3 (MEG3) on cisplatin (DDP) chemoresistance and cell processes in SCLC.

MATERIALS AND METHODS

Quantitative real-time PCR was conducted to determine the expression levels of MEG3, miR-15a-5p, and CCNE1. Cell viability and metastasis were measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-h-tetrazolium bromide and invasion assays, respectively. A xenograft tumor model was developed to confirm the effect of MEG3 overexpression on SCLC progression in vivo. Relationships between miR-15a-5p and MEG3/CCNE1 were predicted using StarBase software and validated by dual luciferase reporter assay. Western blotting was used to determine protein levels. A co-culture model was established to explore the effects of exosomes on MEG3 expression in SCLC cell lines.

RESULTS

MEG3 was overexpressed in SCLC tissues and cells. MEG3 silencing significantly repressed cell viability and metastasis in SCLC. High expression of MEG3 was observed in CAF-derived conditioned medium (CM) and exosomes, and promoted chemoresistance and cancer progression. Additionally, MEG3 was found to serve as a sponge of miR-15a-5p to mediate CCNE1 expression. Overexpression of miR-15a-5p and knockout of CCNE1 reversed the effects of MEG3 overexpression on cell viability and metastasis.

CONCLUSION

MEG3 lncRNA released from CAF-derived exosomes promotes DDP chemoresistance via regulation of a miR-15a-5p/CCNE1 axis. These findings may provide insight into SCLC therapy.

Evaluating the expression of tumorigenic long noncoding RNAs in circulating exosomes isolated from non-small-cell lung cancer patients

Aim: To evaluate the correlation of long noncoding RNAs (lncRNAs) expression in circulating exosomes and the cancerous and noncancerous tissues in patients with non-small-cell lung carcinoma. Methods: The relative expression of the four lncRNAs including LUADT1, MALAT1, NEAT1 and MIAT between tumor tissue, adjacent noncancerous tissues and circulating exosomes were evaluated by quantitative reverse transcription PCR. Results & conclusion: The relative expression of the lncRNAs, including LUADT1, MALAT1 and NEAT1, was upregulated and MIAT was downregulated in tumor tissue compared with noncancerous tissue samples. The expression of lncRNAs in circulating exosomes was not significantly different from cancerous tissue. Our results indicate that the studied exosomal lncRNAs have a good potential to be further evaluated as prognostic/diagnostic biomarkers in patients with non-small-cell lung cancer.

Down-regulation of lncRNA LUADT1 suppresses cervical cancer cell growth by sequestering microRNA-1207-5p

Emerging evidence has proved the essential roles of long non-coding RNAs (lncRNAs) in cervical carcinoma (CC). LncRNA lung adenocarcinoma-associated transcript 1 (LUADT1) is overexpressed and plays an oncogenic role in various cancers; however, the function and clinical values of LUADT1 in CC remain unclear. In this study we found that LUADT1 is highly expressed in CC tissues and cells. Up-regulated LUADT1 is significantly correlated with the more aggressive status and poorer survival of CC patients. studies show that LUADT1 depletion suppresses CC proliferation, and leads to cell apoptosis and cell cycle arrest. Furthermore, the xenograft mouse assay demonstrates that LUADT1 knockdown remarkably suppresses tumor growth. Mechanistically, LUADT1 binds to miR-1207-5p and inhibits miR-1207-5p expression in CC cells. Septin 9 (SEPT9) is identified as a miR-1207-5p target which is negatively regulated by LUADT1. Overexpression of SEPT9 abrogates the suppressed proliferation of CC cells induced by LUADT1 knockdown. These results demonstrate that LUADT1 sponges miR-1207-5p and consequently modulates SEPT9 expression in CC. Our study suggests the possible application of LUADT1 as a prognostic and therapeutic target to inhibit CC.

miR-15a-3p Protects Against Isoniazid-Induced Liver Injury via Suppressing N-Acetyltransferase 2 Expression

Isoniazid (INH), an effective first-line drug for tuberculosis treatment, has been reported to be associated with hepatotoxicity for decades, but the underlying mechanisms are poorly understood. N-acetyltransferase 2 (NAT2) is a Phase II enzyme that specifically catalyzes the acetylation of INH, and NAT2 expression/activity play pivotal roles in INH metabolism, drug efficacy, and toxicity. In this study, we systematically investigated the regulatory roles of microRNA (miRNA) in NAT2 expression and INH-induced liver injury via a series of in silico, in vitro, and in vivo analyses. Four mature miRNAs, including hsa-miR-15a-3p, hsa-miR-628-5p, hsa-miR-1262, and hsa-miR-3132, were predicted to target the NAT2 transcript, and a negative correlation was observed between hsa-miR-15a-3p and NAT2 transcripts in liver samples. Further experiments serially revealed that hsa-miR-15a-3p was able to interact with the 3′-untranslated region (UTR) of NAT2 directly, suppressed the endogenous NAT2 expression, and then inhibited INH-induced NAT2 overexpression as well as INH-induced liver injury, both in liver cells and mouse model. In summary, our results identified hsa-miR-15a-3p as a novel epigenetic factor modulating NAT2 expression and as a protective module against INH-induced liver injury, and provided new clues to elucidate the epigenetic regulatory mechanisms concerning drug-induced liver injury (DILI).

Long non-coding RNA LUADT1 promotes nasopharyngeal carcinoma cell proliferation and invasion by downregulating miR-1207-5p

Nasopharyngeal carcinoma (NPC) is a typical type of malignant tumor. This research paper aims to study the function and mechanism of long non-coding RNA lung adenocarcinoma-related transcript 1 (lncRNA-LUADT1) in the progression of NPC. In this study, the expressions of lncRNA-LUADT1, miR-1207-5p, and TEAD1 in NPC tissues and cell lines were detected by RT-qPCR. Initially, the expression of lncRNA-LUADT1 and TEAD1 were significantly up-regulated in NPC tissues and cells, while miR-1207-5p was significantly down-regulated. Next, miR-1207-5p was confirmed to bind to lncRNA-LUADT1 or TEAD1 by bioinformatics and luciferase reporter assay. In addition, after interfering with lncRNA-LUADT1 expression, experiments of CCK8, EDU staining, and Transwell invasion were used to detect proliferation, invasion, and migration of NPC cells. The results showed that interfering with lncRNA-LUADT1 expression could inhibit the proliferation, invasion, and migration of NPC cells. Western blot showed that lncRNA-LUADT1 knockdown significantly decreased the expression of Hippo/YAP pathway protein (YAP1 and TAZ). However, interfering with the expression of miR-1207-5p reversed these results. In addition, the nude mouse tumor formation experiment suggested that low-expressed lncRNA-LUADT1 reduced the volume and weight of tumor tissues. In summary, lncRNA-LUADT1 down-regulation could inhibit NPC cell proliferation and invasion, which may be achieved through regulating miR-1207-5p expression and affecting TEAD1 expression, thus inhibiting the activation of Hippo/YAP signaling pathway.

MiR-15a-3p regulates ferroptosis via targeting glutathione peroxidase GPX4 in colorectal cancer

Colorectal cancer (CRC) is the second most common cancer-related deaths throughout the world. Ferroptosis is a recently regulated form of cell death, lately gains attention. MicroRNA-15a-3p (miR-15a-3p) plays a regulatory role in various kinds of cancers. However, the role of miR-15a-3p in cellular ferroptosis is still unclear. Here, we aimed to clarify whether miR-15a-3p could regulate the ferroptosis of CRC. Here we identified miR-15a-3p positively regulates ferroptosis via directly targeting glutathione peroxidase glutathione peroxidase 4 (GPX4) in CRC. Overexpression of miR-15a-3p repressed GPX4 through binding to the 3'-untranslated region of GPX4, resulting in increased reactive oxygen species level, intracellular Fe²⁺ level, and malondialdehyde accumulation in vitro and in vivo. Correspondingly, suppression of miR-15a-3p reduced the sensitivity of CRC cells to erastin and GPX4. Taken together, these data demonstrate that miR-15a-3p regulates ferroptosis through targeting GPX4 in CRC cells, illustrating the novel role of microRNA in ferroptosis.

LncRNA FGD5-AS1 promotes the malignant phenotypes of ovarian cancer cells via targeting miR-142-5p

Long non-coding RNAs (lncRNAs) have been reported to participate in regulating gene expression and are related to tumor progression. FGD5 antisense RNA 1 (FGD5-AS1) facilitates the progression of various tumors. However, the expression and function of FGD5-AS1 in ovarian cancer (OC) and its mechanism of action are not yet clear. Real-time polymerase chain reaction (RT-PCR) was employed to explore the expression levels of FGD5-AS1 and miR-142-5p in OC. The relationship between the expression of FGD5-AS1 and clinicopathological indicators of OC patients was analyzed by χ² test. CCK-8 assay, BrdU assay, and Transwell assay were carried out to detect cell proliferation, migration, as well as invasion, respectively. Subcutaneous tumorigenesis experiment and lung metastasis model were used to examine the biological effects of FGD5-AS1 in OC in vivo. Dual luciferase reporter gene assay or RIP experiment was employed to explore the targeting relationship between FGD5-AS1 and miR-142-5p, as well as miR-142-5p and PD-L1 3'UTR. First, we found that FGD5-AS1 was markedly up-regulated in OC. Moreover, its high expression level was associated with positive local lymph node metastasis and higher T stage in OC patients. Gain-of-function and loss-of-function assays demonstrated that FGD5-AS1 facilitated the proliferation, migration, as well as invasion of OC cells. Mechanistically, it was revealed that FGD5-AS1 targeted miR-142-5p to repress its expression and function. Furthermore, miR-142-5p has a binding site for 3' UTR of PD-L1, and FGD5-AS1 could positively regulate PD-L1 expression via repressing miR-142-5p. The present study reports that FGD5-AS1/miR-142-5p/PD-L1 axis is involved in regulating OC progression.

The interplay between non-coding RNAs and Twist1 signaling contribute to human disorders

Twist-related protein 1 (Twist1) is a basic helix-loop-helix (bHLH) transcription factor (TF) being coded by the TWIST1 gene. This TF has a fundamental effect on the normal development and in the pathogenesis of various diseases especially cancer. Twist1 has interactions with some long non-coding RNAs and miRNAs. The interactions between this TF and various miRNAs such as miR-16, miR-26b-5p, miR-1271, miR-539, miR-214, miR-200b/c, miR-335, miR-10b, and miR-381 are implicated in the carcinogenic processes. TP73-AS1, LINC01638, ATB, NONHSAT101069, CASC15, H19, PVT1, LINC00339, LINC01385, TANAR, SNHG5, DANCR, CHRF, and TUG1 are among long non-coding RNAs which interact with Twist1 and participate in the carcinogenesis. This review aims at depicting the interaction between these non-coding transcripts and Twist1 and the consequence of these interactions in human neoplasms.

Long non-coding RNAs as potential biomarkers in the prognosis and diagnosis of lung cancer: A review and target analysis

Long non-coding RNAs (lncRNA) have been emerged as a novel class of molecular regulators in cancer. They are dysregulated in many types of cancer; however, there is not enough knowledge available on their expression and functional profiles. Lung cancer is the leading cause of the cancer deaths worldwide. Generally, lncRNAs may be associated with lung tumor pathogenesis and they may act as biomarkers for the cancer prognosis and diagnosis. Compared to other invasive prognostic and diagnostic methods, detection of lncRNAs might be a user-friendly and noninvasive method. In this review article, we selected 27 tumor-associated lncRNAs by literature reviewing to further discussing in detail for using as diagnostic and prognostic biomarkers in lung cancer. Also, in an in silico target analysis, the "Experimentally supported functional regulation" approach of the LncTarD web tool was used to identifying the target genes and regulatory mechanisms of the selected lncRNAs. The reports on diagnostic and prognostic potential of all selected lncRNAs were discussed. However, the target genes and regulatory mechanisms of the 22 lncRNAs were identified by in silico analysis and we found the pathways that are controlled by each target group of lncRNAs. They use epigenetic mechanisms, ceRNA mechanisms, protein interaction and sponge mechanism. Also, 10, 23, 5, and 28 target genes for each of these mechanisms were identified, respectively. Finally, each group of target genes controls 50, 12, 7, and 2 molecular pathways, respectively. In conclusion, LncRNAs could be used as biomarkers in lung cancer due to their roles in control of several signaling pathways related to lung tumors. Also, it seems that lncRNAs, which use epigenetic mechanisms for modulating a large number of pathways, could be considered as important subjects for lung cancer-related diagnostic and prognostic biomarkers.

Biological functions of long noncoding RNAs and circular RNAs in small-cell lung cancer

We aim to discuss comprehensively the role of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in small-cell lung cancer (SCLC) biology and their clinical utility as cancer biomarkers. We searched the scientific literature to select articles related to the role of lncRNAs and circRNAs in SCLC biology or as cancer biomarkers. We identified that a number of lncRNAs and circRNAs can regulate key biological processes involved in SCLC development, including cell proliferation, metastasis and chemoresistance mainly acting as miRNA sponges. Also, the expression of a few lncRNAs and circRNAs predicted survival outcome depicting their utility as prognostic biomarkers. Further investigations on the role of lncRNAs and circRNAs in SCLC tumors may yield novel therapeutic targets for SCLC.