lncRNA KRAL reverses 5-fluorouracil resistance in hepatocellular carcinoma cells by acting as a ceRNA against miR-141

Regulatory role of non-coding RNAs in 5-Fluorouracil resistance in gastrointestinal cancers

Gastrointestinal (GI) cancers are becoming a growing cause of morbidity and mortality globally, posing a significant risk to human life and health. The main treatment for this kind of cancer is chemotherapy based on 5-fluorouracil (5-FU). However, the issue of 5-FU resistance is becoming increasingly prominent, which greatly limits its effectiveness in clinical treatment. Recently, numerous studies have disclosed that some non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), exert remarkable physiological functions within cells. In addition, these ncRNAs can also serve as important information communication molecules in the tumor microenvironment and regulate tumor chemotherapy resistance. In particular, they have been shown to play multiple roles in regulating 5-FU resistance in GI cancers. Herein, we summarize the targets, pathways, and mechanisms involved in regulating 5-FU resistance by ncRNAs and briefly discuss the application potential of ncRNAs as biomarkers or therapeutic targets for 5-FU resistance in GI cancers, aiming to offer a reference to tackle issues related to 5-FU resistance.

Lipid Nanoparticle (LNP) -A Vector Suitable for Evolving Therapies for Advanced Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) stands as the predominant form of primary liver cancer, characterized by a dismal prognosis. Therapeutic options for advanced HCC remain sparse, with efficacy significantly hampered by the emergence of drug resistance. In parallel with research into novel pharmacological agents, advances in drug delivery systems represent a promising avenue for overcoming resistance. Lipid nanoparticles (LNPs) have demonstrated considerable efficacy in the delivery of nucleic acid-based therapeutics and hold potential for broader applications in drug delivery. This review describes the development of LNPs tailored for HCC treatment and consolidates recent investigations using LNPs to target HCC.

RNA biomarkers in cancer therapeutics: The promise of personalized oncology

Cancer therapy is a rapidly evolving and constantly expanding field. Current approaches include surgery, conventional chemotherapy and novel biologic agents as in immunotherapy, that together compose a wide armamentarium. The plethora of choices can, however, be clinically challenging in prescribing the most suitable treatment for any given patient. Fortunately, biomarkers can greatly facilitate the most appropriate selection. In recent years, RNA-based biomarkers have proven most promising. These molecules that range from small noncoding RNAs to protein coding gene transcripts can be valuable in cancer management and especially in cancer therapeutics. Compared to their DNA counterparts which are stable throughout treatment, RNA-biomarkers are dynamic. This allows prediction of success prior to treatment start and can identify alterations in expression that could reflect response. Moreover, improved nucleic acid technology allows RNA to be extracted from practically every biofluid/matrix and evaluated with exceedingly high analytic sensitivity. In addition, samples are largely obtained by minimally invasive procedures and as such can be used serially to assess treatment response real-time. This chapter provides the reader insight on currently known RNA biomarkers, the latest research employing Artificial Intelligence in the identification of such molecules and in clinical decisions driving forward the era of personalized oncology.

KEAP1 overexpression is correlated with poor prognosis and immune infiltration in liver hepatocellular carcinoma

Purpose

Liver hepatocellular carcinoma (LIHC) is the most common type of liver cancer, but there is a lack of effective indicators for its early diagnosis and prognosis, so we explored the role of KEAP1 in LIHC patients in this study.

Methods

The Cancer Genome Atlas (TCGA) dataset was used to investigate the relationship between KEAP1 expression and clinicopathological features and prognosis of LIHC patients. KEAP1 expression related pathways were enriched by Gene Ontology (GO) and gene set enrichment analysis (GSEA). Besides, KEAP1 expression-related immune infiltration was performed by single-sample GSEA (ssGSEA), and function of immune cells was detected by flow cytometry.

Results

It was found that KEAP1 expression was significantly increased and correlated with overall survival of LIHC patients. A total of 231 differentially expressed genes (DEGs) between LIHC patients with high- and low-KEAP1 expression were found, which associated with various biological pathways. Besides, KEAP1 expression was positively correlated with the infiltration level of T helper cells and Th2 cells but negatively correlated with DCs and cytotoxic cells. Functional analysis revealed that the expression of IL 4 in Th2 cells and CD107a, GrA and GrB in cytotoxic cells was significantly greater in LIHC patients than in HCs. In addition, KEAP1 expression was closely correlated with liver function in LIHC patients.

Conclusion

Highly expressed KEAP1 was closely related to the diagnosis, prognosis, immune cell infiltration, and liver function of LIHC, which might promote the progression of LIHC through regulating cell development, signal transduction, and abnormal immune response. The current study partially revealed the role of KEAP1 in LIHC and provided a potential biomarker for the diagnosis, prognosis and treatment of LIHC.

2-(4-Nitrophenyl)isothiazol-3(2H)-one: A Promising Selective Agent against Hepatocellular Carcinoma Cells

Liver cancer ranks among the most prevalent malignancies globally and stands as a leading cause of cancer-related mortality. Numerous isothiazolone derivatives and analogues have been synthesized and investigated for their potential as anticancer agents; however, limited data exist regarding their efficacy against liver cancer. In the present study, two nitrophenyl-isothiazolones, the 5-benzoyl-2-(4-nitrophenyl)isothiazol-3(2H)-one (IsoA) and the 2-(4-nitrophenyl)isothiazol-3(2H)-one (IsoB), were preliminarily investigated for their cytotoxicity against hepatoma human (Huh7) cells as a liver cancer model and Immortalized Human Hepatocytes (IHHs) as a model of non-cancerous hepatocytes. IsoB, derived from IsoA after removal of the benzoyl moiety, demonstrated the highest cytotoxic effect against Huh7 cells with CC50 values of 19.3 μΜ at 24 h, 16.4 μΜ at 48 h, and 16.2 μΜ at 72 h of incubation, respectively. IsoB also exhibited selective toxicity against the liver cancerous Huh7 cells compared to IHH cells, reinforcing its role as a potent and selective anticancer agent. Remarkably, the cytotoxicity of IsoB was higher when compared with the standard chemotherapeutical agent 5-fluorouracil (5-FU), which also failed to exhibit higher toxicity against the liver cancerous cell lines. Moreover, IsoB-treated Huh7 cells presented a noteworthy reduction in mitochondrial membrane potential (ΔΨm) after 48 and 72 h, while mitochondrial superoxide levels showed an increase after 24 h of incubation. The molecular mechanism of the IsoB cytotoxic effect was also investigated using RT-qPCR, revealing an apoptosis-mediated cell death along with tumor suppressor TP53 overexpression and key-oncogene MYCN downregulation.

Novel Insights on Ferroptosis Modulation as Potential Strategy for Cancer Treatment: When Nature Kills

Significance: The multifactorial nature of the mechanisms implicated in cancer development still represents a major issue for the success of established antitumor therapies. The discovery of ferroptosis, a novel form of programmed cell death distinct from apoptosis, along with the identification of the molecular pathways activated during its execution, has led to the uncovering of novel molecules characterized by ferroptosis-inducing properties. Recent advances: As of today, the ferroptosis-inducing properties of compounds derived from natural sources have been investigated and interesting findings have been reported both in vitro and in vivo. Critical Issues: Despite the efforts made so far, only a limited number of synthetic compounds have been identified as ferroptosis inducers, and their utilization is still limited to basic research. In this review, we analyzed the most important biochemical pathways involved in ferroptosis execution, with particular attention to the newest literature findings on canonical and non-canonical hallmarks, together with mechanisms of action of natural compounds identified as novel ferroptosis inducers. Compounds have been classified based on their chemical structure, and modulation of ferroptosis-related biochemical pathways has been reported. Future Directions: The outcomes herein collected represent a fascinating starting point from which to take hints for future drug discovery studies aimed at identifying ferroptosis-inducing natural compounds for anticancer therapies. Antioxid. Redox Signal. 40, 40-85.

Retracted: Long noncoding RNA RHPN1-AS1, induced by KDM5B, is involved in breast cancer via sponging miR-6884-5p

The above article, published online in Journal of Cellular Biochemistry on 31 January 2020 in Wiley Online Library (https://doi.org/10.1002/jcb.29645), has been retracted by agreement between the authors, the journal's Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The authors asked to retract their article after substantial mistakes in experimental data were found, thus the results are considered to be invalid.

Long noncoding RNAs induced control of ferroptosis: Implications in cancer progression and treatment

A novel kind of nonapoptotic, iron-dependent cell death brought on by lipid peroxidation is known as ferroptosis. Numerous pathological processes, including neurotoxicity, neurological disorders, ischemia-reperfusion damage, and particularly cancer, have been demonstrated to be influenced by changes in the ferroptosis-regulating network. Recent studies have established the critical roles that ferroptosis can play in cancer development and the evolution of resistance to standard chemoradiotherapy, thus suggesting that ferroptosis may be a feasible therapeutic strategy for cancer management. Gene expression may be regulated at the transcriptional and posttranscriptional levels by long noncoding RNAs (lncRNAs). They have been implicated in tumorigenesis. Some lncRNAs participate in the biological process of ferroptosis, which represents an exciting alternative to regulate ferroptosis as a means of cancer therapy. Even though there is evidence that lncRNAs have a mechanistic role in the ferroptosis of cancer cells, research on the mechanism and potential treatments for these lncRNAs is still lacking. We elucidate the potential mechanisms by which lncRNAs modulate ferroptosis in cancer and examine the promise and challenges of employing lncRNAs as novel therapeutic targets in cancer.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

Emerging role of miRNAs in the regulation of ferroptosis

Ferroptosis is a kind of cell death which has distinctive features differentiating it from autophagy, necrosis and apoptosis. This iron-dependent form of cell death is described by an increase in lipid reactive oxygen species, shrinkage of mitochondria and decrease in mitochondrial cristae. Ferroptosis is involved in the initiation and progression of many diseases and is regarded as a hotspot of investigations on treatment of disorders. Recent studies have shown that microRNAs partake in the regulation of ferroptosis. The impact of microRNAs on this process has been verified in different cancers as well as intervertebral disc degeneration, acute myocardial infarction, vascular disease, intracerebral hemorrhage, preeclampsia, hemorrhagic stroke, atrial fibrillation, pulmonary fibrosis and atherosclerosis. miR-675, miR-93, miR-27a, miR-34a and miR-141 have been shown to affect iron metabolism, antioxidant metabolism and lipid metabolism, thus influencing all pivotal mechanisms in the ferroptosis process. In the current review, we summarize the role of microRNAs in ferroptosis and their involvement in the pathetiology of malignant and non-malignant disorders.

Interplay between Non-Coding RNAs and NRF2 in Different Cancers: Spotlight on MicroRNAs and Long Non-Coding RNAs

Cancer is a multifactorial disease, and a wealth of information has enabled basic and clinical researchers to develop a better conceptual knowledge of the highly heterogeneous nature of cancer. Deregulations of spatio-temporally controlled transduction pathways play a central role in cancer progression. NRF2-driven signaling has engrossed significant attention because of its fundamentally unique features to dualistically regulate cancer progression. Context-dependent diametrically opposed roles of NRF2-induced signaling are exciting. More importantly, non-coding RNA (ncRNA) mediated regulation of NRF2 and interplay between NRF2 and ncRNAs have added new layers of complexity to already intricate nature of NRF2 signaling. There is a gradual enrichment in the existing pool of knowledge related to interplay between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in different cancers. However, surprisingly, there are no clues about interplay between circular RNAs and NRF2 in various cancers. Therefore, future studies must converge on the functional characterization of additional important lncRNAs and circular RNAs, which regulated NRF2-driven signaling or, conversely, NRF2 transcriptionally controlled their expression to regulate various stages of cancer. SIGNIFICANCE STATEMENT: Recently, many researchers have focused on the NRF2-driven signaling in cancer progression. Excitingly, discovery of non-coding RNAs has added new layers of intricacy to the already complicated nature of KEAP1/NRF2 signaling in different cancers. These interactions are shaping the NRF2-driven signaling landscape, and better knowledge of these pathways will be advantageous in pharmacological modulation of non-coding RNA-mediated NRF2 signaling in various cancers.

Metabolic reprogramming by miRNAs in the tumor microenvironment: Focused on immunometabolism

MicroRNAs (miRNAs) are emerging as a significant modulator of immunity, and their abnormal expression/activity has been linked to numerous human disorders, such as cancer. It is now known that miRNAs potentially modulate the production of several metabolic processes in tumor-associated immune cells and indirectly via different metabolic enzymes that affect tumor-associated signaling cascades. For instance, Let-7 has been identified as a crucial modulator for the long-lasting survival of CD8+ T cells (naive phenotypes) in cancer by altering their metabolism. Furthermore, in T cells, it has been found that enhancer of zeste homolog 2 (EZH2) expression is controlled via glycolytic metabolism through miRNAs in patients with ovarian cancer. On the other hand, immunometabolism has shown us that cellular metabolic reactions and processes not only generate ATP and biosynthetic intermediates but also modulate the immune system and inflammatory processes. Based on recent studies, new and encouraging approaches to cancer involving the modification of miRNAs in immune cell metabolism are currently being investigated, providing insight into promising targets for therapeutic strategies based on the pivotal role of immunometabolism in cancer. Throughout this overview, we explore and describe the significance of miRNAs in cancer and immune cell metabolism.

Reactive Oxygen Species and Long Non-Coding RNAs, an Unexpected Crossroad in Cancer Cells

Long non-coding RNAs (lncRNA) have recently been identified as key regulators of oxidative stress in several malignancies. The level of reactive oxygen species (ROS) must be constantly regulated to maintain cancer cell proliferation and chemoresistance and to prevent apoptosis. This review will discuss how lncRNAs alter the ROS level in cancer cells. We will first describe the role of lncRNAs in the nuclear factor like 2 (Nrf-2) coordinated antioxidant response of cancer cells. Secondly, we show how lncRNAs can promote the Warburg effect in cancer cells, thus shifting the cancer cell’s “building blocks” towards molecules important in oxidative stress regulation. Lastly, we explain the role that lncRNAs play in ROS-induced cancer cell apoptosis and proliferation.

Effect of long noncoding RNA CCAT2 on drug sensitivity to 5-fluorouracil of breast cancer cells through microRNA-145 meditated by p53

The current study was set out to investigate the mechanism by which silenced long noncoding RNA (lncRNA) colon cancer-associated transcript 2 (CCAT2) modulates the cell growth, migration, invasion, and drug sensitivity of breast cancer (BC) cells to 5-fluorouracil (5-Fu) with the involvement of miR-145 and p53. First, high CCAT2 expression was presented in BC cells and tissues. Subsequently, the links between CCAT2 expression and BC clinicopathological features were analyzed. Highly-expressed CCAT2 was linked to lymph node metastasis, positive progesterone receptor, estrogen receptor, and Ki-67 of BC cells. Then, the gain- and loss-of-function approaches were performed to measure the regulatory role of CCAT2 in the biological processes of BC cells. Silencing of CCAT2 suppressed in vitro cell growth, proliferation, invasion, migration abilities, and epithelial-mesenchymal transformation, increased cell apoptosis, and enhanced drug sensitivity of BC cells. Silencing of CCAT2 upregulated miR-145, which was poorly expressed in drug-resistant BC cells. p53 can bind to the miR-145 promoter region and increase miR-145 expression. Upregulation of miR-145 induced by silencing of CCAT2 can be invalidated by p53-siRNA. To conclude, p53-induced activation of miR-145 could be inhibited by CCAT2, while overexpression of CCAT2 could improve the drug resistance of BC cells to 5-Fu.

Non-coding RNAs in ferroptotic cancer cell death pathway: meet the new masters

Despite the recent advances in cancer therapy, cancer chemoresistance looms large along with radioresistance, a major challenge in dire need of thorough and minute investigation. Not long ago, cancer cells were reported to have proven refractory to the ferroptotic cell death, a newly discovered form of regulated cell death (RCD), conspicuous enough to draw attention from scholars in terms of targeting ferroptosis as a prospective therapeutic strategy. However, our knowledge concerning the underlying molecular mechanisms through which cancer cells gain immunity against ferroptosis is still in its infancy. Of late, the implication of non-coding RNAs (ncRNAs), including circular RNAs (circRNAs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) in ferroptosis has been disclosed. Nevertheless, precisely explaining the molecular mechanisms behind the contribution of ncRNAs to cancer radio/chemotherapy resistance remains a challenge, requiring further clarification. In this review, we have presented the latest available information on the ways and means of regulating ferroptosis by ncRNAs. Moreover, we have provided important insights about targeting ncRNAs implicated in ferroptosis with the hope of opening up new horizons for overcoming cancer treatment modalities. Though a long path awaits until we make this ambitious dream come true, recent progress in gene therapy, including gene-editing technology will aid us to be optimistic that ncRNAs-based ferroptosis targeting would soon be on stream as a novel therapeutic strategy for treating cancer.

Identification of lncRNA/circRNA-miRNA-mRNA ceRNA Network as Biomarkers for Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) accounts for the majority of liver cancer, with the incidence and mortality rates increasing every year. Despite the improvement of clinical management, substantial challenges remain due to its high recurrence rates and short survival period. This study aimed to identify potential diagnostic and prognostic biomarkers in HCC through bioinformatic analysis.

Methods: Datasets from GEO and TCGA databases were used for the bioinformatic analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were carried out by WebGestalt website and clusterProfiler package of R. The STRING database and Cytoscape software were used to establish the protein-protein interaction (PPI) network. The GEPIA website was used to perform expression analyses of the genes. The miRDB, miRWalk, and TargetScan were employed to predict miRNAs and the expression levels of the predicted miRNAs were explored via OncomiR database. LncRNAs were predicted in the StarBase and LncBase while circRNA prediction was performed by the circBank. ROC curve analysis and Kaplan-Meier (KM) survival analysis were performed to evaluate the diagnostic and prognostic value of the gene expression, respectively.

Results: A total of 327 upregulated and 422 downregulated overlapping DEGs were identified between HCC tissues and noncancerous liver tissues. The PPI network was constructed with 89 nodes and 178 edges and eight hub genes were selected to predict upstream miRNAs and ceRNAs. A lncRNA/circRNA-miRNA-mRNA network was successfully constructed based on the ceRNA hypothesis, including five lncRNAs (DLGAP1-AS1, GAS5, LINC00665, TYMSOS, and ZFAS1), six circRNAs (hsa_circ_0003209, hsa_circ_0008128, hsa_circ_0020396, hsa_circ_0030051, hsa_circ_0034049, and hsa_circ_0082333), eight miRNAs (hsa-miR-150-5p, hsa-miR-19b-3p, hsa-miR-23b-3p, hsa-miR-26a-5p, hsa-miR-651-5p, hsa-miR-10a-5p, hsa-miR-214-5p and hsa-miR-486-5p), and five mRNAs (CDC6, GINS1, MCM4, MCM6, and MCM7). The ceRNA network can promote HCC progression via cell cycle, DNA replication, and other pathways. Clinical diagnostic and survival analyses demonstrated that the ZFAS1/hsa-miR-150-5p/GINS1 ceRNA regulatory axis had a high diagnostic and prognostic value.

Conclusion: These results revealed that cell cycle and DNA replication pathway could be potential pathways to participate in HCC development. The ceRNA network is expected to provide potential biomarkers and therapeutic targets for HCC management, especially the ZFAS1/hsa-miR-150-5p/GINS1 regulatory axis.

KCNQ1OT1 affects cell proliferation, invasion, and migration through a miR-34a / Notch3 axis in breast cancer

BACKGROUND

Breast cancer (BC) accounts for a significant share of cancer-related deaths worldwide. Ongoing investigations have shown that long non-coding RNAs (lncRNAs) drive BC progression but their underlying mechanisms remain largely undescribed. LncRNA KCNQ1OT1 was previously identified in BC but its functional significance remained to be fully investigated.

METHODS

KCNQ1OT1 and its downstream target genes were analyzed in breast cancer tissues and cell lines using methods including RT-qPCR, immunohistochemistry and Western blotting. The effects of KCNQ1OT1, miR-34a and Notch3 on BC cells were investigated using assays measuring proliferation (CCK-8, colony formation), apoptosis, and migration/invasion (scratch and Transwell assays). MS2-RIP and dual-luciferase reporter assays were used to study RNA interactions. Xenograft studies were employed to define the tumorigenic potential of KCNQ1OT1 in vivo.

RESULTS

KCNQ1OT1 expression was up-regulated in BC tissues and high levels were associated with poorer prognosis. ShRNA inhibition of KCNQ1OT1 expression in BC cell lines retarded proliferation, migration and invasion in vitro and tumor growth in vivo. Up-regulation of KCNQ1OT1 was shown to inhibit miR-34a which was associated with blocking the inhibitory effect of miR-34a on BC cell proliferation, migration and invasion. Notch3 was found to be a downstream target of miR-34a with KCNQ1OT1 markedly inducing Notch3 expression in BC. Evidence for KCNQ1OT1/miR-34a/Notch3 axis was further established in clinical BC samples.

CONCLUSION

We identified a KCNQ1OT1/miR-34a/Notch3 axis which promotes BC progression through effects on cell proliferation and metastasis that was further associated with poor patient prognosis. These results propose targeting this axis as novel treatment approach for BC.

CDK Inhibition Reverses Acquired 5-Fluorouracil Resistance in Hepatocellular Carcinoma Cells

Background. 5-Fluorouracil (5-FU) has been widely applied in treating cancers. However, its usage is largely limited in hepatocellular carcinoma (HCC), due to acquired resistance. Here, we aim to identify target proteins and investigate their roles in 5-FU sensitivity of HCC cells. Methods. Mass spectrometry (MS) proteomics was performed on 5-FU-resistant cell line (BEL7402/5-FU) and its parental cell line (BEL7402) with 5-FU treatment. In order to identify potential targets, we compared the proteomics between two cell line groups and used bioinformatics tools to select hub proteins from all differentially expressed proteins. Results. We finally focused on a group of cell cycle-related kinases (CDKs). By CCK8 assay, we confirmed that the CDK inhibitor significantly decreased the IC50 of 5-FU-resistant cells. Conclusions. Our study verified that CDK inhibition can reverse 5-FU resistance of HCC cells.

The Role of Ferroptosis in the Treatment and Drug Resistance of Hepatocellular Carcinoma

Cell death is a fundamental feature of multicellular organisms’ development and a key driver of degenerative diseases. Ferroptosis is a new regulatory cell death mediated by iron-dependent lipid peroxidation, which is different from apoptosis and necrosis in morphology, pathophysiology and mechanism. Recent studies have found that ferroptosis is involved in the development of many diseases including hepatocellular carcinoma (HCC). As further research progresses, specific mechanisms of ferroptosis in HCC are being revealed. In this review, we summarize these recent advances about the treatment of drug-resistance in HCC and the latest ferroptosis-related treatment for HCC.

Close interactions between lncRNAs, lipid metabolism and ferroptosis in cancer

Abnormal lipid metabolism including synthesis, uptake, modification, degradation and transport has been considered a hallmark of malignant tumors and contributes to the supply of substances and energy for rapid cell growth. Meanwhile, abnormal lipid metabolism is also associated with lipid peroxidation, which plays an important role in a newly discovered type of regulated cell death termed ferroptosis. Long noncoding RNAs (lncRNAs) have been proven to be associated with the occurrence and progression of cancer. Growing evidence indicates that lncRNAs are key regulators of abnormal lipid metabolism and ferroptosis in cancer. In this review, we mainly summarized the mechanism by which lncRNAs regulate aberrant lipid metabolism in cancer, illustrated that lipid metabolism can also influence the expression of lncRNAs, and discussed the mechanism by which lncRNAs affect ferroptosis. A comprehensive understanding of the interactions between lncRNAs, lipid metabolism and ferroptosis could help us to develop novel strategies for precise cancer treatment in the future.

The Mechanism of miR-141 Regulating the Proliferation and Metastasis of Liver Cancer Cells by Targeting STAT4

Background

In recent years, it has been reported that miRNA can be used as one of the markers of tumor diagnosis, treatment, and prognosis (including liver cancer), and it plays an important role in tumorigenesis. However, there are still very few studies on the mechanism and role of miR-141 in liver cancer.

Methods

qRT-PCR was used to test the expressions of miR-141 and STAT4 in collected liver cancer tissues and adjacent tissues, cultured liver cancer cell lines MHCC97H, Hep3B, and Huh7, and normal human liver cells HL7702. After processing the results of the qRT-PCR experiment, liver cancer cell MHCC97H which has the lowest expression level was decided to be taken as the research object. miR-NC, miR-141 mimics, si-NC, si-STAT4, miR-141 mimics and pcDNA-NC, and miR-141 mimics and pcDNA-STAT4 were transfected into MHCC97H cells, respectively. The MTT assay was used to detect the proliferation of each group of cells, and the Transwell test was used to detect the effect of miR-141 on cell proliferation, migration, and invasion. The interaction between miR-141 and STAT4 was verified by the dual-luciferase reporter experiment, and the expression level of Cyclin D1 and MMP2 was detected by the western blot.

Results

Compared with normal cell HL7702, the expression level of miR-141 in liver cancer cell lines was relatively low (P < 0.05) and the expression level of STAT4 in liver cancer cell lines was relatively high (P < 0.05) after testing the expression level of STAT4; transfecting miR-141 mimics or Si-SLBP can inhibit cell proliferation, migration, and invasion; dual-luciferase reporter experiments confirmed that miR-141 can specifically bind to the 3′UTR of STAT4; cotransfection of miR-141 mimics and pcDNA-STAT4 can antagonize the effects of miR-141 mimics on cell proliferation, migration, and invasion.

Conclusion

miR-141 can target the STAT4 gene expression to inhibit the proliferation, migration, and invasion of liver cancer cells.

LncRNA ENSG00000254615 Modulates Proliferation and 5-FU Resistance by Regulating p21 and Cyclin D1 in Colorectal Cancer

5-Fluorouracil (5-FU) resistance is an urgent problem of colorectal cancer (CRC) chemotherapy that needs to be resolved. To investigate 5-FU-associated lncRNAs for CRC might be of great significant. LncRNA ENSG00000254615 was detected by RNA-sequencing. ENSG00000254615 were detected highly expressed in 5-FU-sensitive CRC cells and tissue specimens, and inhibited cell proliferation and attenuated 5-FU resistance in vitro and in vivo. Furthermore, ENSG00000254615 participated in the regulation of p21 and Cyclin D1. Taken together, we proposed that ENSG00000254615 inhibits proliferation and attenuates 5-FU resistance of CRC by regulating p21 and Cyclin D1 expression.

Expression, regulation, and function of exosome-derived miRNAs in cancer progression and therapy

Exosomes are a novel class of intercellular signal modulators that contain a wide range of molecules and deliver information between cells and tissues. MicroRNAs (miRNAs), a type of regulatory non-coding RNA, are often incorporated into exosomes as signaling molecules. In this review, we discuss the expression of exosomal miRNAs from diverse origins such as tumor cells, solid tumor tissue, and biological fluids in various cancers (lung, breast, colorectal, liver, stomach, and pancreatic). We address the biological functions of exosome-derived miRNAs in processes such as tumor-cell proliferation, angiogenesis, metastasis, and chemoresistance in the tumor microenvironment. In particular, we discuss three oncogenic miRNAs, miR-21, miR-141, and miR-451, which occur within exosomes, in terms of gene regulation and intercellular communication. We consider therapeutic miRNA-based nanoparticles, which are widely expressed in tumors and show promise in drug therapy. The review assesses the wide-ranging evidence for using exosomal miRNAs as tumor markers in molecular diagnosis. Further, we consider the use of nanoparticle platforms to transport miRNAs, in the targeted treatment of disease and tumors.

Targeting Long Non-Coding RNAs in Hepatocellular Carcinoma: Progress and Prospects

Hepatocellular carcinoma is the fifth-ranked cancer worldwide with a relatively low five-year survival rate. Long non-coding RNAs are a group of RNAs with remarkable aberrant expression which could act on multiple bioprocesses and ultimately impact upon tumor proliferation, invasion, migration, metastasis, apoptosis, and therapy resistance in cancer cells including hepatocellular carcinoma cells. In recent years, long non-coding RNAs have been reported to be indispensable targets in clinical target therapy to stop the growth of cancer and prolong the lifespan of patients with hepatocellular carcinoma. In this review, we enumerate the signaling pathways and life activities affected by long non-coding RNAs in hepatocellular carcinoma cells to illustrate the role of long non-coding RNAs in the development and therapy resistance of hepatocellular carcinoma.

CircKEAP1 Suppresses the Progression of Lung Adenocarcinoma via the miR-141-3p/KEAP1/NRF2 Axis

Background

Lung cancer is the leading cause of death from cancer, and lung adenocarcinoma (LUAD) is the most common form. Despite the great advances that has been made in the diagnosis and treatment for LUAD, the pathogenesis of LUAD remains unclear. In this study, we aimed to identify the function of circKEAP1 derived from the exon of KEAP1 in LUAD.

Methods

The expression profiles of circRNAs in LUAD tissues and adjacent non-tumor tissues were analyzed by Agilent Arraystar Human CircRNA microarray. The levels and prognostic values of circKEAP1 in tissues and cancer cell lines were determined by quantitative real-time PCR (qRT-PCR). Subsequently, the effects of circKEAP1 on tumor growth were investigated by functional experiments in vitro and in vivo. Mechanistically, the dual luciferase reporter assay, RNA pull-down, and RNA immunoprecipitation experiments were performed to confirm the interaction between circKEAP1 and miR-141-3p in LUAD.

Results

We found circKEAP1 was significantly downregulated in LUAD tissues and repressed tumor growth both in vitro and in vivo. Mechanistically, circKEAP1 competitively binds to miR-141-3p and relive miR-141-3p repression for its host gene, which activated the KEAP1/NRF2 signal pathway, and finally suppresses the tumor progress. Our findings suggest that circKEAP1 inhibits LUAD progression through circKEAP1/miR-141-3p/KEAP1 axis and it may serve as a novel method for the treatment of LUAD.

linc‑ROR facilitates hepatocellular carcinoma resistance to doxorubicin by regulating TWIST1‑mediated epithelial‑mesenchymal transition

Long non‑coding RNAs are associated with cancer progression. Long intergenic non‑protein coding RNA (linc)‑regulator of reprogramming (ROR) enhances tumor development in hepatocellular carcinoma (HCC). However, the effect of chemoresistance and its underlying mechanisms in HCC are not completely understood. The present study aimed to identify the effect of ROR on sensitivity to doxorubicin (DOX) in HCC cells. In the present study, Cell Counting Kit‑8 and EdU assays were performed to assess cell viability and proliferation, respectively. In addition, E‑cadherin and vimentin protein expression levels were assessed via western blotting and immunofluorescence.The results of the present study demonstrated that HCC cells with high linc‑ROR expression levels were more resistant to DOX, and linc‑ROR knockdown increased HCC cell DOX sensitivity compared with the control group. The results indicated that compared with the NC siRNA group, linc‑ROR knockdown notably suppressed epithelial‑mesenchymal transition by downregulating twist family bHLH transcription factor 1 (TWIST1) expression. TWIST1 knockdown displayed a similar effect on HCC cell DOX sensitivity to linc‑ROR knockdown. Moreover, linc‑ROR knockdown‑induced HCC cell DOX sensitivity was inhibited by TWIST1 overexpression. The present study provided evidence that linc‑ROR promoted HCC resistance to DOX by inducing EMT via interacting with TWIST1. Therefore, linc‑ROR might serve as a therapeutic target for reducing DOX resistance in HCC.

Development and Validation of a RNA Binding Protein-Associated Prognostic Model for Hepatocellular Carcinoma

BACKGROUND

Dysregulation of RNA binding proteins (RBPs) has been identified in multiple malignant tumors correlated with tumor progression and occurrence. However, the function of RBPs is not well understood in hepatocellular carcinoma (HCC).

METHODS

The RNA sequence data of HCC was extracted out of the Cancer Genome Atlas (TCGA) database and different RBPs were calculated between regular and cancerous tissue. The study explored the expression and predictive value of the RBPs systemically with a series of bioinformatic analyzes.

RESULTS

A total of 330 RBPs, including 208 up-regulated and 122 down-regulated RBPs, were classified differently. Four RBPs (MRPL54, EZH2, PPARGC1A, EIF2AK4) were defined as the forecast related hub gene and used to construct a model for prediction. Further study showed that the high-risk subgroup is poor survived (OS) compared to the model-based low-risk subgroup. The area of the prognostic model under the time-dependent receiver operator characteristic (ROC) curve is 0.814 in TCGA training group and 0.729 in validation group, indicating a strong prognostic model. We also created a predictive nomogram and a web-based calculator (https://dxyjiang.shinyapps.io/RBPpredict/) based on the 4 RBPs and internal validation in the TCGA cohort, which displayed a beneficial predictive ability for HCC.

CONCLUSIONS

Our results provide new insights into HCC pathogenesis. The 4-RBP gene signature showed a reliable HCC prediction ability with possible applications in therapeutic decision making and personalized therapy.

5-Fluorouracil: A Narrative Review on the Role of Regulatory Mechanisms in Driving Resistance to This Chemotherapeutic Agent

5-fluorouracil (5-FU) is among the mostly administrated chemotherapeutic agents for a wide variety of neoplasms. Non-coding RNAs have a central impact on the determination of the response of patients to 5-FU. These transcripts via modulation of cancer-related pathways, cell apoptosis, autophagy, epithelial-mesenchymal transition, and other aspects of cell behavior can affect cell response to 5-FU. Modulation of expression levels of microRNAs or long non-coding RNAs may be a suitable approach to sensitize tumor cells to 5-FU treatment via modulating multiple biological signaling pathways such as Hippo/YAP, Wnt/β-catenin, Hedgehog, NF-kB, and Notch cascades. Moreover, there is an increasing interest in targeting these transcripts in various kinds of cancers that are treated by 5-FU. In the present article, we provide a review of the function of non-coding transcripts in the modulation of response of neoplastic cells to 5-FU.

The FENDRR/FOXC2 Axis Contributes to Multidrug Resistance in Gastric Cancer and Correlates With Poor Prognosis

The dysregulation of long non-coding RNAs (lncRNAs) and transcription factors (TFs) is closely related to the development and progression of drug resistance in cancer chemotherapy. However, their regulatory interactions in the multidrug resistance (MDR) of gastric cancer (GC) has largely remained unknown. In this study, we report a novel oncogenic role of lncRNA FENDRR in conferring MDR in GC by coordinated regulation of FOXC2 expression at the transcriptional and posttranscriptional levels. In vitro and in vivo experiments demonstrated that downregulation of FENDRR expression remarkably decreased drug resistant ability of GC MDR cells while upregulation of FENDRR expression produced the opposite effect. FENDRR overexpression was observed in MDR GC cell lines, patient-derived xenografts, and clinical samples. And the high levels of FENDRR expression were correlated with poor prognosis in GC patients. Regarding the mechanism, FENDRR was revealed to increase proto-oncogene FOXC2 transcription by performing an enhancer-like role in the nucleus and by sponging miR-4700-3p in the cytoplasm. Both FOXC2 and miR-4700-3p were shown to be functionally involved in the FENDRR-induced chemoresistance. In addition, there is a positive correlation between FENDRR and FOXC2 expression in clinic and the overexpressed FOXC2 indicated a poor prognosis in GC patients. Collectively, our findings provide a new perspective for the lncRNA-TF regulatory interaction involved in MDR, suggesting that targeting the FENDRR/FOXC2 axis may be an effective approach to circumvent GC chemoresistance.

Upregulated UCA1 contributes to oxaliplatin resistance of hepatocellular carcinoma through inhibition of miR-138-5p and activation of AKT/mTOR signaling pathway

Hepatocellular carcinoma (HCC) inevitably developed oxaliplatin (OXA) resistance after long-term treatment, but the mechanism remains unclear. Here, we found that LncRNA UCA1 was upregulated in most of OXA-resistant HCC tissues and cells (HepG2/OXA and SMMC-7721/OXA). Follow-up analysis and online Kaplan-Meier Plotter revealed that HCC patients with high UCA1 level had a shorter survival compared with those with low expression. Overexpression of UCA1 increased OXA IC50 in HepG2 and SMMC-7721 cells, whereas knockdown of UCA1 decreased OXA IC50 in resistant counterparts. Moreover, dual luciferase reporter assay showed that co-transfection of UCA1-WT plasmid with miR-138-5p mimics enhanced fluorescence signals, whereas co-transfection of UCA1-Mut plasmid and miR-138-5p mimics did not induce any changes. Consistently, UCA1 levels in HepG2/OXA and SMMC-7721/OXA cells were downregulated after transfected with miR-138-5p mimics. UCA1 silencing or transfection of miR-138-5p mmics inhibited the activation of AKT and mTOR in HepG2/OXA and SMMC-7721/OXA cells, whereas UCA1 overexpression increased the phosphorylated AKT and mTOR levels in parental counterparts. Rapamycin or miR-138-5p mimics similarly suppressed the activation of AKT and mTOR, whereas UCA1 overexpression exert opposite roles. Interestingly, administration of rapamycin or miR-138-5p mimics apparently antagonized the effects of UCA1 on AKT and mTOR activation. Besides, depletion of UCA1 triggered more dramatic regression of HepG2 xenografts than that of HepG2/OXA xenografts with OXA treatment and impaired the p-AKT and p-mTOR levels in vivo. In conclusion, our findings provide the evidence that UCA1 may contribute to OXA resistance via miR-138-5p-mediated AK /mTOR activation, suggesting that UCA1 is a potential therapeutic target for HCC.

LINC00680 enhances hepatocellular carcinoma stemness behavior and chemoresistance by sponging miR-568 to upregulate AKT3

BACKGROUND

Hepatocellular carcinoma (HCC) has an extremely poor prognosis due to the development of chemoresistance, coupled with inherently increased stemness properties. Long non-coding RNAs (LncRNAs) are key regulators for tumor cell stemness and chemosensitivity. Currently the relevance between LINC00680 and tumor progression was still largely unknown, with only one study showing its significance in glioblastoma. The study herein was aimed at identifying the role of LINC00680 in the regulation HCC stemness and chemosensitivity.

METHODS

QRT-PCR was used to detect the expression of LINC00680, miR-568 and AKT3 in tissue specimen and cell lines. Gain- or loss-of function assays were applied to access the function of LINC00680 in HCC cells, including cell proliferation and stemness properties. HCC stemness and chemosensitivity were determined by sphere formation, cell viability and colony formation. Luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were performed to examine the interaction between LINC00680 and miR-568 as well as that between miR-568 and AKT3. A nude mouse xenograft model was established for the in vivo study.

RESULTS

We found that LINC00680 was remarkably upregulated in HCC tissues. Patients with high level of LINC00680 had poorer prognosis. LINC00680 overexpression significantly enhanced HCC cell stemness and decreased in vitro and in vivo chemosensitivity to 5-fluorouracil (5-Fu), whereas LINC00680 knockdown led to opposite results. Mechanism study revealed that LINC00680 regulated HCC stemness and chemosensitivity through sponging miR-568, thereby expediting the expression of AKT3, which further activated its downstream signaling molecules, including mTOR, elF4EBP1, and p70S6K.

CONCLUSION

LINC00680 promotes HCC stemness properties and decreases chemosensitivity through sponging miR-568 to activate AKT3, suggesting that LINC00680 might be a potentially important HCC diagnosis marker and therapeutic target.

Long Non-Coding RNAs: Potential Biomarkers and Targets for Hepatocellular Carcinoma Therapy and Diagnosis

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Increasing studies showed that long non-coding RNAs (lncRNAs), a novel class of RNAs that are greater than 200 nucleotides in length but lack the ability to encode proteins, exert crucial roles in the occurrence and progression of HCC. LncRNAs promote the proliferation, migration, invasion, autophagy, and apoptosis of tumor cells by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can be used as biomarkers to predict the efficacy of HCC treatment strategies, such as surgery, radiotherapy, chemotherapy, and immunotherapy, and as a potential individualized tool for HCC diagnosis and treatment. In this review, we overview up-to-date findings on lncRNAs as potential biomarkers for HCC surgery, radiotherapy, chemotherapy resistance, target therapy, and immunotherapy, and discuss the potential clinical application of lncRNA as tools for HCC diagnosis and treatment.

MicroRNA-200a and microRNA-141 have a synergetic effect on the suppression of epithelial-mesenchymal transition in liver cancer by targeting STAT4

MicroRNAs (miRNAs or miRs) are non-coding small RNAs that target specific messenger RNAs to inhibit protein translation. miR-200a and miR-141 function as tumor suppressors by targeting STAT4. These two miRNAs belong to the same family, and their expression is often decreased in various cancer types, but are located on different chromosomes of the human genome. The present study showed that the expression levels of miR-141 and miR-200a in serum and cells of liver cancer are significantly downregulated. The expression levels of miR-141 and miR-200a are closely associated with clinicopathological features of liver cancer, especially metastasis and invasion. It is first reported that STAT4 is the new common target gene of miR-141 and miR-200a. In the present study, miR-141 and miR-200a were confirmed to inhibit the expression of E-cadherin and vimentin synergistically during epithelial-mesenchymal transition to regulate the proliferation, migration and invasion of liver cancer cells by targeting STAT4. Simultaneous overexpression of miR-200a and miR-141 resulted in stronger effects compared with each miRNA alone. In addition, overexpression of STAT4 significantly reversed the tumor suppressive roles of miR-200a and miR-141 in liver cancer cells. These findings enrich the tumor suppressor mechanisms of the miR-200 family, and may also provide new experimental and theoretical basis for the use of miRNAs for early diagnosis, prognosis and thorough treatment of liver cancer.

Sustained expression of MCP-1 induced low wall shear stress loading in conjunction with turbulent flow on endothelial cells of intracranial aneurysm

Shear stress was reported to regulate the expression of AC007362, but its underlying mechanisms remain to be explored. In this study, to isolate endothelial cells of blood vessels, unruptured and ruptured intracranial aneurysm (IA) tissues were collected from IA patients. Subsequently, quantitative real‐time PCR (qRT‐PCR), Western blot and luciferase assay were performed to investigate the relationships between AC007362, miRNAs‐493 and monocyte chemoattractant protein‐1 (MCP‐1) in human umbilical vein endothelial cells (HUVECs) exposed to shear stress. Reduced representation bisulphite sequencing (RRBS) was performed to assess the level of DNA methylation in AC007362 promoter. Accordingly, AC007362 and MCP‐1 were significantly up‐regulated while miR‐493 was significantly down‐regulated in HUVECs exposed to shear stress. AC007362 could suppress the miR‐493 expression and elevate the MCP‐1 expression, and miR‐493 was shown to respectively target AC007362 and MCP‐1. Moreover, shear stress in HUVECs led to the down‐regulated DNA methyltransferase 1 (DNMT1), as well as the decreased DNA methylation level of AC007362 promoter. Similar results were also observed in ruptured IA tissues when compared with unruptured IA tissues. In conclusion, this study presented a deep insight into the operation of the regulatory network of AC007362, miR‐493 and MCP‐1 upon shear stress. Under shear stress, the expression of AC007362 was enhanced by the inhibited promoter DNA methylation, while the expression of MCP‐1 was enhanced by sponging the expression of miR‐493.

Oxidative Stress and Cancer Development: Are Noncoding RNAs the Missing Links?

Significance: It is now clear that genetic changes underlie the basis of cancer, and alterations in functions of multiple genes are responsible for the process of tumorigenesis. Besides the classical genes that are usually implicated in cancer, the role of noncoding RNAs (ncRNAs) and reactive oxygen species (ROS) as independent entitites has also been investigated. Recent Advances: The microRNAs and long noncoding RNAs (lncRNAs), two main classes of ncRNAs, are known to regulate many aspects of tumor development. ROS, generated during oxidative stress and pathological conditions, are known to regulate every step of tumor development. Conversely, oxidative stress and ROS producing agents can suppress tumor development. The malignant cells normally produce high levels of ROS compared with normal cells. The interaction between ROS and ncRNAs regulates the expression of multiple genes and pathways implicated in cancer, suggesting a unique mechanistic relationship among ncRNA-ROS-cancer. The mechanistic relationship has been reported in hepatocellular carcinoma, glioma, and malignancies of blood, breast, colorectum, esophagus, kidney, lung, mouth, ovary, pancreas, prostate, and stomach. The ncRNA-ROS regulate several cancer-related cell signaling pathways, namely, protein kinase B (AKT), epidermal growth factor receptor (EGFR), forkhead box O3 (FOXO3), kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), p53, phosphatase and tensin homologue (PTEN), and wingless-related integration site (Wnt)/glycogen synthase kinase-3 beta (GSK3β). Critical Issues: To date, most of the reports about ncRNA-oxidative stress-carcinogenesis relationships are based on cell lines. The mechanistic basis for this relationship has not been completely elucidated. Future Directions: Attempts should be made to explore the association of lncRNAs with ROS. The significance of the ncRNA-oxidative stress-carcinogenesis interplay should also be explored through studies in animal models.

NRF2 Regulation by Noncoding RNAs in Cancers: The Present Knowledge and the Way Forward

Simple Summary

The NRF2 pathway represents one of the most intriguing pathways that promotes chemo- and radioresistance of neoplastic cells. Increasing findings suggest that the NRF2 signaling can be modulated by multiple epigenetic factors such as noncoding RNAs, which influence a large number of oncogenic mechanisms, both at transcriptional and at post-transcriptional levels. As a consequence, the identification and characterization of specific noncoding RNAs as biomarkers related to oxidative stress may help to clarify the relationship between them and NRF2 signaling in the tumor context, in terms of positive and negative modulation, also referring to their intersection with other NRF2 crosstalking pathways. In this review, we summarize the recent updates on NRF2 network regulation by noncoding RNAs in tumors, thus paving the way toward the potential translational role of these small RNAs as key tumor biomarkers of neoplastic processes.

Abstract

Nuclear factor erythroid 2-related factor 2 (NRF2) is the key transcription factor triggered by oxidative stress that moves in cells of the antioxidant response element (ARE)-antioxidant gene network against reactive oxygen species (ROS) cellular damage. In tumors, the NRF2 pathway represents one of the most intriguing pathways that promotes chemo- and radioresistance of neoplastic cells and its activity is regulated by genetic and epigenetic mechanisms; some of these being poorly investigated in cancer. The noncoding RNA (ncRNA) network is governed by microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) and modulates a variety of cellular mechanisms linked to cancer onset and progression, both at transcriptional and post-transcriptional levels. In recent years, the scientific findings about the effects of ncRNA landscape variations on NRF2 machines are rapidly increasing and need to be continuously updated. Here, we review the latest knowledge about the link between NRF2 and ncRNA networks in cancer, thus focusing on their potential translational significance as key tumor biomarkers.

Progress of long noncoding RNAs in anti-tumor resistance

The resistance of cancer cells to anti-cancer drugs is an important reason for the failure of treatment. Overcoming drug resistance can achieve long-lasting and efficient cancer treatment. Long non-coding RNA (lncRNA) is a class of RNA molecules that does not encode protein and has more than 200 nucleotides. LncRNA not only has a regulatory role in the occurrence and development of malignant tumors, but also has been found to have a potential impact on anti-tumor resistance. Abnormal expression of lncRNA can cause tumor cells to develop resistance to anti-tumor drugs. This article reviews the recent research progress of lncRNA in various tumor resistances and the mechanism of lncRNA acting on tumor drug resistance.

Revisiting cancer hallmarks: insights from the interplay between oxidative stress and non-coding RNAs

Cancer is one of the most common disease worldwide, with complex changes and certain traits which have been described as “The Hallmarks of Cancer.” Despite increasing studies on in-depth investigation of these hallmarks, the molecular mechanisms associated with tumorigenesis have still not yet been fully defined. Recently, accumulating evidence supports the observation that microRNAs and long noncoding RNAs (lncRNAs), two main classes of noncoding RNAs (ncRNAs), regulate most cancer hallmarks through their binding with DNA, RNA or proteins, or encoding small peptides. Reactive oxygen species (ROS), the byproducts generated during metabolic processes, are known to regulate every step of tumorigenesis by acting as second messengers in cancer cells. The disturbance in ROS homeostasis leads to a specific pathological state termed “oxidative stress”, which plays essential roles in regulation of cancer progression. In addition, the interplay between oxidative stress and ncRNAs is found to regulate the expression of multiple genes and the activation of several signaling pathways involved in cancer hallmarks, revealing a potential mechanistic relationship involving ncRNAs, oxidative stress and cancer. In this review, we provide evidence that shows the essential role of ncRNAs and the interplay between oxidative stress and ncRNAs in regulating cancer hallmarks, which may expand our understanding of ncRNAs in the cancer development from the new perspective.

Long non-coding RNA LINC00473 acts as a microRNA-29a-3p sponge to promote hepatocellular carcinoma development by activating Robo1-dependent PI3K/AKT/mTOR signaling pathway

Background:

Long non-coding RNAs have suppressive or oncogenic effects in various types of cancers by serving as competing endogenous RNAs for specific microRNAs. In the present study, we aim to delineate the underlying mechanism by which the LINC00473/miR-29a-3p/Robo1 axis affects cell proliferation, migration, invasion, and metastasis in hepatocellular carcinoma (HCC).

Methods:

The level of Robo1 was examined in HCC tissues and cells, along with its regulatory effects on proliferation, migration, and invasion of HCC cells. Afterwards, the possible involvement of the PI3K/AKT/mTOR signaling pathway was determined. Next, miR-29a-3p expression was overexpressed or inhibited to investigate its regulatory role on HCC cell activities. The interaction among miR-29a-3p, Robo1, and LINC00473 was further characterized. Finally, a xenograft tumor in nude mice was conducted to measure tumorigenesis and metastasis in vivo.

Results:

miR-29a-3p was downregulated while Robo1 was upregulated in HCC tissues and cells. miR-29a-3p targeted Robo1 and negatively regulated its expression. In response to miR-29a-3p overexpression, Robo1 silencing or LINC00473 silencing, HCC cell proliferation, migration, invasion, tumor progression, and metastasis were impeded, which was involved with the inactivation of the PI3K/AKT/mTOR signaling pathway. Notably, LINC00473 could competitively bind to miR-29a-3p to upregulate Robo1 expression.

Conclusion:

LINC00473 might be involved in HCC progression by acting as a miR-29a-3p sponge to upregulate the expression of Robo1 that activates the PI3K/AKT/mTOR signaling pathway, which leads to enhanced cell proliferation, migration, invasion, tumor progression, and metastasis in HCC.

Role of long noncoding RNA-mediated competing endogenous RNA regulatory network in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are noncoding RNAs (ncRNAs) that occupy over 90% of the human genome, and their main function is to directly or indirectly regulate messenger RNA (mRNA) expression and participate in the tumorigenesis and progression of malignances. In particular, some lncRNAs can interact with miRNAs as competing endogenous RNAs (ceRNAs) to modulate mRNA expression. Accordingly, these RNA molecules are interrelated and coordinate to form a dynamic lncRNA-mediated ceRNA regulatory network. Mounting evidence has revealed that lncRNAs that act as ceRNAs are closely related to tumorigenesis. To date, numerous studies have established many different regulatory networks in hepatocellular carcinoma (HCC), and perturbations in these ceRNA interactions may result in the initiation and progression of HCC. Herein, we emphasize recent advances concerning the biological function of lncRNAs as ceRNAs in HCC, with the aim of elucidating the molecular mechanism underlying these HCC-related RNA molecules and providing novel insights into the diagnosis and treatment of HCC.

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.

Risk Scoring System based on lncRNA Expression for Predicting Survival in Hepatocellular Carcinoma with Cirrhosis

Objective:

This study aims to explore the roles of long non-coding RNAs (lncRNAs) for predicting survival in hepatocellular carcinoma (HCC) patients with cirrhosis.

Methods:

A set of lncRNAs differentially expressed between HCC patients with or without cirrhosis was identified using expression profiles of The Cancer Genome Atlas database, and these lncRNAs were screened for their risk scoring system to predict recurrence-free survival (RFS) or overall survival (OS). Predictive ability of risk scoring systems was confirmed using uni- and multivariate Cox analyses while adjusting for clinical features. Predictive lncRNAs were analyzed by functional enrichment analysis.

Results:

Our screen identified 22 lncRNAs that were upregulated in the presence of cirrhosis and 59 that were downregulated. To predict OS of HCC patients with cirrhosis, a risk scoring system was developed with four lncRNAs (LINC02086, LINC00880, LINC01549 and AC136475.3); to predict RFS in these patients, the risk scoring system contained five lncRNAs (SH3RF3-AS1, AC104117.3, AC136475.3, LINC00239 and MRPL23-AS1). All risk scoring systems were associated with an area under the receiver operating characteristic curve > 0.7. Based on uni- and multivariate Cox analyses, the risk scoring system could serve as a significant independent predictor for OS in HCC patients with cirrhosis. Functional enrichment analysis suggested that the lncRNAs in the risk scoring systems are involved primarily in the pathway of Wnt signal and cytokine-cytokine receptor interaction.

Conclusion:

Risk scoring systems based on lncRNAs can effectively predict OS of HCC patients with cirrhosis. The system should be further developed and validated in larger, preferably multi-site patient populations.

Roles of DANCR/microRNA-518a-3p/MDMA ceRNA network in the growth and malignant behaviors of colon cancer cells

Background

The competing endogenous RNA (ceRNA) networks of long non-coding RNAs (lncRNAs) and microRNAs (miRs) have aroused wide concerns. The study aims to investigate the roles of lncRNA DANCR-associated ceRNA network in the growth and behaviors of colon cancer (CC) cells.

Methods

Differentially expressed lncRNAs between CC and paracancerous tissues were analyzed using microarrays and RT-qPCR. Follow-up studies were conducted to evaluate the correlation between DANCR expression and prognosis of CC patients. Loss-of-functions of DANCR were performed to identify its role in the malignant behaviors of CC cells. Sub-cellular localization of DANCR and the potential targets of DANCR were predicted and validated. Cells with inhibited DANCR were implanted into nude mice to evaluate the tumor formation and metastasis in vivo.

Results

DANCR was highly-expressed in CC tissues and cell lines, and higher levels of DANCR were linked with worse prognosis and less survival time of CC patients. Silencing of DANCR inhibited proliferation, viability, metastasis and resistance to death of CC cells. DANCR was found to be sub-localized in cytoplasmic matrix and to mediate murine double minute 2 (MDM2) expression through sponging miR-518a-3p in CC cells, during which the Smad2/3 signaling was activated. Likewise, silencing of DANCR in CC cells inhibited tumor formation and metastasis in vivo.

Conclusion

This study provided evidence that silencing of DANCR might inhibit the growth and metastasis of CC cells through the DANCR/miR-518a-3p/MDM2 ceRNA network and the defect of Smad2/3 while activation of the p53 signaling pathways. This study may offer novel insights in CC treatment.

The Underlying Mechanisms of Noncoding RNAs in the Chemoresistance of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal human malignancies. Chemotherapeutic agents, such as sorafenib and lenvatinib, can improve the outcomes of HCC patients. Nevertheless, chemoresistance has become a major hurdle in the effective treatment of HCC. Noncoding RNAs (ncRNAs), including mircoRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), have been demonstrated to participate in the onset and progression of HCC. Moreover, multiple lines of evidence have indicated that ncRNAs also play a pivotal role in HCC drug resistance. ncRNAs can regulate drug efflux and metabolism, glucose metabolism, cellular death pathways, and malignant characteristics in HCC. A deeper understanding of the molecular mechanisms responsible for ncRNA-mediated drug resistance in HCC will provide new opportunities for improving the treatment of HCC. In this review, we summarize recent findings on the molecular mechanisms by which ncRNAs regulate HCC chemoresistance, as well as their potential clinical implications in overcoming HCC chemoresistance.

Risk scoring based on expression of long non‑coding RNAs can effectively predict survival in hepatocellular carcinoma patients with or without fibrosis

Patients with hepatocellular carcinoma (HCC) have different prognoses depending on whether or not they also have fibrosis. Since long non-coding RNAs (lncRNAs) affect tumor formation and progression, the present study aimed to investigate whether their expression might help predict the survival of patients with HCC. Expression profiles downloaded from The Cancer Genome Atlas database were examined to identify lncRNAs differentially expressed (DElncRNAs) between HCC patients with or without fibrosis. These DElncRNAs were then used to develop a risk scoring system to predict overall survival (OS) or recurrence-free survival (RFS). A total of 142 significant DElncRNAs were identified using data from 135 patients with fibrosis and 72 without fibrosis. For HCC patients with fibrosis, a risk scoring system to predict OS was constructed based on five lncRNAs (AL359853.1, Z93930.3, HOXA-AS3, AL772337.1 and AC012640.3), while the risk scoring system to predict RFS was based on 12 lncRNAs (PLCE1-AS1, Z93930.3, LINC02273, TRBV11-2, HHIP-AS1, AC004687.1, LINC01857, AC004585.1, AP000808.1, CU638689.4, AC090152.1 and AL357060.1). For HCC patients without fibrosis, the risk scoring system to predict OS was established based on seven lncRNAs (LINC00239, AC104971.4, AP006285.2, HOXA-AS3, AC079834.2, NRIR and LINC01929), and the system to predict RFS was based on five lncRNAs (AC021744.1, NRIR, LINC00487, AC005858.1 and AC107398.3). Areas under the receiver operating characteristic curves for all risk scoring systems exceeded 0.7. Uni- and multivariate Cox analyses showed that the risk scoring systems were significant independent predictors of OS for HCC patients with fibrosis, or of OS and RFS for HCC patients without fibrosis, after adjusting for clinical factors. Functional enrichment analysis suggested that, depending on the risk scoring system, highly associated genes were involved in pathways mainly associated with the cell cycle, chemokines, Th17 cell differentiation or thermogenesis. The findings of the present study indicate that risk scoring systems based on lncRNA expression can effectively predict the OS of HCC patients with fibrosis as well as the OS or RFS of HCC patients without fibrosis.

LncRNA KRAL suppresses cell growth and increases sensitivity to doxorubicin in osteosarcoma cells by sponging microRNAs-141

Osteosarcoma (OS) is one of the most common types of malignant tumors characterized by uncontrolled proliferation ability and acquired drug resistance. The previous study indicated that lncRNA KRAL participated in the reversal of 5-FU resistance in liver cancer, but it remains unclear whether lncRNA KRAL involved in doxorubicin (DOX) resistance of osteosarcoma. The expression of lncRNA KRAL and MicroRNAs-141 (miR-141) were detected by RT-qPCR experiment. Also, we used the plasmids transfection to construct the lncRNA KRAL overexpressed OS cell lines. Subsequently, the cell proliferation ability and the sensitivity to DOX in OS cells upon upregulating lncRNA KRAL expression were analyzed via CCK-8 and EDU assay, while western blotting experiment was performed to detect the regulatory mechanism. We found that lncRNA KRAL was downregulated in OS tissues, and the OS patients with OS patients with lower expression of lncRNA KRAL were more likely to have advanced Enneking stage, larger tumor size and distant metastasis. Subsequently, we discovered that upregulation of lncRNA KRAL could inhibit cell proliferation and increase the sensitivity to DOX of OS cells. Interestingly, the western blot results showed that over-expression of lncRNA KRAL could lead to down-expression of P-gp protein and reversal of Epithelial–mesenchymal transition (EMT) pathway. Furthermore, we identified miR-141 as the downstream target gene of lncRNA KRAL, which was further confirmed by the luciferase reporter assay. More importantly, our data demonstrated that addition of miR-141 could reverse cell proliferation and drug sensitivity of lncRNA KRAL-overexpressed OS cells. LncRNA KRAL could suppress cell growth and increases sensitivity to DOX in OS cells by sponging miR-141.

Long non-coding RNA F11-AS1 inhibits HBV-related hepatocellular carcinoma progression by regulating NR1I3 via binding to microRNA-211-5p

Long non-coding RNAs (lncRNAs) could regulate growth and metastasis of hepatocellular carcinoma (HCC). In this study, we aimed to investigate the mechanism of lncRNA F11-AS1 in hepatitis B virus (HBV)-related HCC. The relation of lncRNA F11-AS1 expression in HBV-related HCC tissues to prognosis was analysed in silico. Stably HBV-expressing HepG2.2.15 cells were established to explore the regulation of lncRNA F11-AS1 by HBx protein, as well as to study the effects of overexpressed lncRNA F11-AS1 on proliferation, migration, invasion and apoptosis in vitro. Subsequently, the underlying interactions and roles of lncRNA F11-AS1/miR-211-5p/NR1I3 axis in HBV-related HCC were investigated. Additionally, the influence of lncRNA F11-AS1 and miR-211-5p on tumour growth and metastasis capacity of HepG2.2.15 cells were studied on tumour-bearing nude mice. Poor expression of lncRNA F11-AS1 was correlated with poor prognosis in patients with HBV-related HCC, and its down-regulation was caused by the HBx protein. lncRNA F11-AS1 was proved to up-regulate the NR1I3 expression by binding to miR-211-5p. Overexpression of lncRNA F11-AS1 reduced the proliferation, migration and invasion, yet induced apoptosis of HepG2.2.15 cells in vitro, which could be abolished by overexpression of miR-211-5p. Additionally, either lncRNA F11-AS1 overexpression or miR-211-5p inhibition attenuated the tumour growth and metastasis capacity of HepG2.2.15 cells in vivo. Collectively, lncRNA F11-AS1 acted as a modulator of miR-211-5p to positively regulate the expression of NR1I3, and the lncRNA F11-AS1/miR-211-5p/NR1I3 axis participated in HBV-related HCC progression via interference with the cellular physiology of HCC.