Long noncoding RNA linc00462 promotes hepatocellular carcinoma progression

Non-coding RNA mediated regulation of PI3K/Akt pathway in hepatocellular carcinoma: Therapeutic perspectives

Hepatocellular carcinoma (HCC) is among the primary reasons for fatalities caused by cancer globally, highlighting the need for comprehensive knowledge of its molecular aetiology to develop successful treatment approaches. The PI3K/Akt system is essential in the course of HCC, rendering it an intriguing candidate for treatment. Non-coding RNAs (ncRNAs), such as long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are important mediators of the PI3K/Akt network in HCC. The article delves into the complex regulatory functions of ncRNAs in influencing the PI3K/Akt system in HCC. The study explores how lncRNAs, miRNAs, and circRNAs impact the expression as well as the function of the PI3K/Akt network, either supporting or preventing HCC growth. Additionally, treatment strategies focusing on ncRNAs in HCC are examined, such as antisense oligonucleotide-based methods, RNA interference, and small molecule inhibitor technologies. Emphasizing the necessity of ensuring safety and effectiveness in clinical settings, limitations, and future approaches in using ncRNAs as therapies for HCC are underlined. The present study offers useful insights into the complex regulation system of ncRNAs and the PI3K/Akt cascade in HCC, suggesting possible opportunities for developing innovative treatment approaches to address this lethal tumor.

Decoding hepatocarcinogenesis from a noncoding RNAs perspective

Being a leading lethal malignancy worldwide, the pathophysiology of hepatocellular carcinoma (HCC) has gained a lot of interest. Yet, underlying mechanistic basis of the liver tumorigenesis is poorly understood. The role of some coding genes and their respective translated proteins, then later on, some noncoding RNAs (ncRNAs) such as microRNAs have been extensively studied in context of HCC pathophysiology; however, the implication of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in HCC is indeed less investigated. As a subclass of the ncRNAs which has been elusive for long time ago, lncRNAs was found to be involved in plentiful cellular functions such as DNA, RNA, and proteins regulation. Hence, it is undisputed that lncRNAs dysregulation profoundly contributes to HCC via diverse etiologies. Accordingly, lncRNAs represent a hot research topic that requires prime focus in HCC. In this review, the authors discuss breakthrough discoveries involving lncRNAs and circRNAs dysregulation that have contributed to the contemporary concepts of HCC pathophysiology and how these concepts could be leveraged as potential novel diagnostic and prognostic HCC biomarkers. Further, this review article sheds light on future trends, thereby discussing the pathological roles of lncRNAs and circRNAs in HCC proliferation, migration, and epithelial-to-mesenchymal transition. Along this line of reasoning, future recommendations of how these targets could be exploited to achieve effective HCC-related drug development is highlighted.

A comprehensive review of the role of LINC00462 in human disorders

LINC00462; a long intergenic non-coding RNA located on chromosome chr13:48,576,973-48,590,587 is a member of long non-coding RNA (lncRNA) that is participated in different human disorders such as pancreatic cancer and hepatocellular carcinoma. LINC00462 can act as competing endogenous RNAs (ceRNAs), to sponge different MicroRNAs (miRNAs) such as miR-665. Dysregulation of LINC00462 can promote cancer development, progression, and metastasis. LINC00462 can also bind directly with genes and proteins to regulate different pathways, including STAT2/3 and PI3K/AKT pathways to affected tumor progression. In addition, aberrant LINC00462 levels can be important cancer-specific prognostic and diagnostic markers. In this review, we summarize the most recent studies on the role of LINC00462 in different disorders and demonstrated the role of LINC00462 in tumorigenesis.

Long non-coding RNA LINC01793 as a potential diagnostic biomarker of hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

There is growing evidence that long non-coding RNAs (lncRNAs) play important roles in the progression of hepatocellular carcinoma (HCC) and may serve as diagnostic markers. This study investigates the diagnostic efficiency of the long intergenic non-protein-coding RNA 1793 (LINC01793) in hepatitis B virus (HBV)-related HCC.

METHODS

Bioinformatics methods were used to screen the aberrantly expressed lncRNAs in HCC tissues based on The Cancer Genome Atlas (TCGA). Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of the candidate lncRNAs in tissues, cells and whole blood samples of patients with HBV-related HCC, liver cirrhosis (LC), chronic hepatitis (CHB), and healthy controls. Then, the correlations between LINC01793 and clinical characteristics were analyzed. Finally，the diagnostic value of LINC01793 was explored based on the receiver operating characteristic curve.

RESULTS

LINC01793 was remarkably upregulated in the HCC tissues and cells. It was highly expressed in the whole blood of the HBV-related HCC patients, unlike in that of the healthy controls and of the CHB and LC patients. Subsequent analysis revealed that high LINC01793 was related to the Barcelona Clinic Liver Cancer (P = 0.007), tumor invasion (P = 0.042), the number of tumors (P = 0.031) and serum level of alanine aminotransferase(p = 0.022). The areas under the curve of LINC01793, for distinguishing HCC from healthy controls, CHB and LC patients, were 0.824, 0.767 and 0.756, respectively. In addition, the combination of LINC01793 with alpha fetoprotein (AFP) had a stronger diagnostic value than LINC01793 or AFP alone in AFP-negative HCC patients.

CONCLUSION

High expression of LINC01793 is correlated with adverse clinical characteristics and can serve as a non-invasive biomarker of HCC.

Identification of the Ferroptosis-Related Long Non-Coding RNAs Signature to Improve the Prognosis Prediction in Papillary Renal Cell Carcinoma

Papillary renal cell carcinoma (pRCC) is one of the epithelial renal cell carcinoma (RCC) histological subtypes. Ferroptosis is a new iron-dependent form of cell death that has been seen in a variety of clinical situations. Using differentially expressed ferroptosis-related long non-coding RNAs (lncRNAs) from patients with pRCC in The Cancer Genome Atlas; we built a prognostic lncRNA-based signature. We discovered seven different lncRNAs that were strongly linked to the prognosis of patients with pRCC. High-risk scores were linked to a poor prognosis for pRCC, which was confirmed by the findings of Kaplan–Meier studies. In addition, the constructed lncRNA signature has a 1-year area under the curve (AUC) of 0.908, suggesting that it has a high predictive value in pRCC. In the high-risk group, Gene set enrichment analyses (GSEA) analysis identified immunological and tumor-related pathways. Furthermore, single-sample GSEA (ssGSEA) revealed significant differences in T cell functions checkpoint, antigen presenting cell (APC) co-stimulation, inflammation promoting, and para inflammation between the two groups with different risk scores. In addition, immune checkpoints like PDCD1LG2 (PD-L2), LAG3, and IDO1 were expressed differently in the two risk groups. In summary, a novel signature based on ferroptosis-related lncRNAs could be applied in predicting the prognosis of patients with pRCC.

An lncRNA Model for Predicting the Prognosis of Hepatocellular Carcinoma Patients and ceRNA Mechanism

Liver cancer is a highly malignant tumor. Notably, recent studies have found that long non-coding RNAs (lncRNAs) play a prominent role in the prognosis of patients with liver cancer. Herein, we attempted to construct an lncRNA model to accurately predict the survival rate in liver cancer. Based on The Cancer Genome Atlas (TCGA) database, we first identified 1066 lncRNAs with differential expression. The patient data obtained from TCGA were divided into the experimental group and the verification group. According to the difference in lncRNAs, we used single-factor and multi-factor Cox regression to select the genes needed to build the model in the experimental group, which were verified in the verification group. The results showed that the model could accurately predict the survival rate of patients in the high and low risk groups. The reliability of the model was also confirmed by the area under the receiver operating characteristic curve. Our model is significantly correlated with different clinicopathological features. Finally, we built a ceRNA network based on lncRNAs, which was used to display miRNAs and mRNAs related to lncRNAs. In summary, we constructed an lncRNA model to predict the survival rate of patients with hepatocellular carcinoma.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

Construction of a novel risk model based on the random forest algorithm to distinguish pancreatic cancers with different prognoses and immune microenvironment features

Immune-related long noncoding RNAs (irlncRNAs) are actively involved in regulating the immune status. This study aimed to establish a risk model of irlncRNAs and further investigate the roles of irlncRNAs in predicting prognosis and the immune landscape in pancreatic cancer. The transcriptome profiles and clinical information of 176 pancreatic cancer patients were retrieved from The Cancer Genome Atlas (TCGA). Immune-related genes (irgenes) downloaded from ImmPort were used to screen 1903 immune-related lncRNAs (irlncRNAs) using Pearson’s correlation analysis (R > 0.5; p < 0.001). Random survival forest (RSF) and survival tree analysis showed that 9 irlncRNAs were highly correlated with overall survival (OS) according to the variable importance (VIMP) and minimal depth. Next, Cox regression analysis was used to establish a risk model with 3 irlncRNAs (LINC00462, LINC01887, RP11-706C16.8) that was evaluated by Kaplan-Meier analysis, the areas under the curve (AUCs) of the receiver operating characteristics and the C-index. Additionally, we performed Cox regression analysis to establish the clinical prognostic model, which showed that the risk score was an independent prognostic factor (p < 0.001). A nomogram and calibration plots were drawn to visualize the clinical features. The Wilcoxon signed-rank test and Pearson’s correlation analysis further explored the irlncRNA signatures and immune cell infiltration, as well as the immunotherapy response.

The Role of RNA Methyltransferase METTL3 in Hepatocellular Carcinoma: Results and Perspectives

Hepatocellular carcinoma (HCC) is the 6th most prevalent cancer and the 4th leading cause of cancer-related death worldwide. Mechanisms explaining the carcinogenesis of HCC are not clear yet. In recent years, rapid development of N⁶-methyladenosine (m6A) modification provides a fresh approach to disclosing this mystery. As the most prevalent mRNA modification in eukaryotes, m6A modification is capable to post-transcriptionally affect RNA splicing, stability, and translation, thus participating in a variety of biological and pathological processes including cell proliferation, apoptosis, tumor invasion and metastasis. METTL3 has been recognized as a pivotal methyltransferase and essential to the performance of m6A modification. METTL3 can regulate RNA expression in a m6A-dependent manner and contribute to the carcinogenesis, tumor progression, and drug resistance of HCC. In the present review, we are going to make a clear summary of the known roles of METTL3 in HCC, and explicitly narrate the potential mechanisms for these roles.

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

PI3K Inhibitors in Cancer: Clinical Implications and Adverse Effects

The phospatidylinositol-3 kinase (PI3K) pathway is a crucial intracellular signaling pathway which is mutated or amplified in a wide variety of cancers including breast, gastric, ovarian, colorectal, prostate, glioblastoma and endometrial cancers. PI3K signaling plays an important role in cancer cell survival, angiogenesis and metastasis, making it a promising therapeutic target. There are several ongoing and completed clinical trials involving PI3K inhibitors (pan, isoform-specific and dual PI3K/mTOR) with the goal to find efficient PI3K inhibitors that could overcome resistance to current therapies. This review focuses on the current landscape of various PI3K inhibitors either as monotherapy or in combination therapies and the treatment outcomes involved in various phases of clinical trials in different cancer types. There is a discussion of the drug-related toxicities, challenges associated with these PI3K inhibitors and the adverse events leading to treatment failure. In addition, novel PI3K drugs that have potential to be translated in the clinic are highlighted.

Long non-coding RNA-based signature for predicting prognosis of hepatocellular carcinoma

Long non-coding RNAs (lncRNAs), as one common type of non-coding RNAs, play a critical role in the tumorigenesis and development of hepatocellular carcinoma (HCC). In the current study, we aimed to assess the correlation between lncRNAs expression levels and prognosis of HCC patients. A lncRNA-based signature was also developed to predict the prognosis of HCC in this work. The lncRNAs expression profiles in tissues of tumor and para-carcinoma were obtained from The Cancer Genome Atlas (TCGA) database. The lncRNA-based prognostic model was established by least absolute shrinkage and selection operator (LASSO). The multivariate Cox-regression analysis was applied to identify the independent risk factors and subsequently developed a prognostic nomogram. Based on the co-expression analyses, we identified the lncRNA-related mRNAs and performed the biological function analysis. Between HCC and para-carcinoma tissues, 220 differentially expressed lncRNAs were filtered. Among these lncRNAs, 19 lncRNAs were identified as prognostic factors and were used to build a prognostic signature of overall survival (OS). Furthermore, a nomogram with high performance for predicting the OS of HCC patients (C-index: 0.779) by combining the 19-lncRNA signature (P < 0.001) and clinicopathologic factors including HBV (P = 0.005) and stage (P =0.017) was established. Functional enrichment analysis revealed that 19 lncRNAs had potential effects on tumor cell proliferation in HCC. In summary, we established a 19-lncRNA signature to predict the prognosis of HCC patients, which may perform a crucial role in guiding the management of HCC.

Integrated Analysis of lncRNA-Mediated ceRNA Network Reveals a Prognostic Signature for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignancy and is associated with high mortality. Prior research suggests that long non-coding RNAs (lncRNAs) play a crucial role in the development of HCC. Therefore, it is necessary to identify lncRNA-associated therapeutic biomarkers to improve the accuracy of HCC prognosis. Transcriptomic data of HCC obtained from The Cancer Genome Atlas (TCGA) database were used in the present study. Differentially expressed RNAs (DERNAs), including 74 lncRNAs, 16 miRNAs, and 35 mRNAs, were identified using bioinformatics analysis. The DERNAs were subsequently used to reconstruct a competing endogenous RNA (ceRNA) network. A lncRNA signature was revealed using Cox regression analysis, including LINC00200, MIR137HG, LINC00462, AP002478.1, and HTR2A-AS1. Kaplan-Meier plot demonstrated that the lncRNA signature is highly accurate in discriminating high- and low-risk patients (P < 0.05). The area under curve (AUC) value exceeded 0.7 in both training and validation cohort, suggesting a high prognostic potential of the signature. Furthermore, multivariate Cox regression analysis indicated that both the TNM stage and the lncRNA signature could serve as independent prognostic factors for HCC (P < 0.05). Then, a nomogram comprising the TNM stage and the lncRNA signature was determined to raise the accuracy in predicting the survival of HCC patients. In the present study, we have introduced a ceRNA network that could contribute to provide a new insight into the identification of potential regulation mechanisms for the development of HCC. The five-lncRNA signature could serve as a reliable biosignature for HCC prognosis, while the nomogram possesses strong potential in clinical applications.

15-lncRNA-Based Classifier-Clinicopathologic Nomogram Improves the Prediction of Recurrence in Patients with Hepatocellular Carcinoma

Background

Our study aims to develop a lncRNA-based classifier and a nomogram incorporating the genomic signature and clinicopathologic factors to help to improve the accuracy of recurrence prediction for hepatocellular carcinoma (HCC) patients.

Methods

The lncRNA profiling data of 374 HCC patients and 50 normal healthy controls were downloaded from The Cancer Genome Atlas (TCGA). Using univariable Cox regression and least absolute shrinkage and selection operator (LASSO) analysis, we developed a 15-lncRNA-based classifier and compared our classifier to the existing six-lncRNA signature. Besides, a nomogram incorporating the genomic classifier and clinicopathologic factors was also developed. The predictive accuracy and discriminative ability of the genomic-clinicopathologic nomogram were determined by a concordance index (C-index) and calibration curve and were compared with the TNM staging system by the C-index and receiver operating characteristic (ROC) analysis. Decision curve analysis (DCA) was performed to estimate the clinical value of our nomogram.

Results

Fifteen relapse-free survival (RFS-) related lncRNAs were identified, and the classifier, consisting of the identified 15 lncRNAs, could effectively classify patients into the high-risk and low-risk subgroups. The prediction accuracy of the 15-lncRNA-based classifier for predicting 2-year and 5-year RFS was 0.791 and 0.834 in the training set and 0.684 and 0.747 in the validation set, respectively, which was better than the existing six-lncRNA signature. Moreover, the AUC of genomic-clinicopathologic nomogram in predicting RFS were 0.837 in the training set and 0.753 in the validation set, and the C-index of the genomic-clinicopathologic nomogram was 0.78 (0.72-0.83) in the training set and 0.71 (0.65-0.76) in the validation set, which was better than the traditional TNM stage and 15-lncRNA-based classifier. The decision curve analysis further demonstrated that our nomogram had a larger net benefit than the TNM stage and 15-lncRNA-based classifier. The results were confirmed externally.

Conclusion

Compared to the TNM stage, the 15-lncRNAs-based classifier-clinicopathologic nomogram is a more effective and valuable tool to identify HCC recurrence and may aid in clinical decision-making.

PI3K/AKT/mTOR pathway-related long non-coding RNAs: roles and mechanisms in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide with high prevalence and lethality. The oncogenic phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is a classic dysregulated pathway involved in the pathogenesis of HCC. However, the underlying mechanism for how PI3K/AKT/mTOR pathway aberrantly activates HCC has not been entirely elucidated. The recognition of the functional roles of long non-coding RNAs (lncRNAs) in PI3K/AKT/mTOR signaling axis sheds light on a new dimension to our understanding of hepatocarcinogenesis. In this review, we comprehensively summarize 67 dysregulated PI3K/AKT/mTOR pathway-related lncRNAs in HCC. Many studies have indicated that the 67 dysregulated lncRNAs show oncogenic or anti-oncogenic effects in HCC by regulation on epigenetic, transcriptional and post-transcriptional levels and they play pivotal roles in the initiation of HCC in diverse biological processes like proliferation, metastasis, drug resistance, radio-resistance, energy metabolism, autophagy and so on. Besides, many of these lncRNAs are associated with clinicopathological features and clinical prognosis in HCC, which may provide a potential future application in the diagnosis and therapy of HCC.

Serum exosomal long noncoding RNAs lnc-FAM72D-3 and lnc-EPC1-4 as diagnostic biomarkers for hepatocellular carcinoma

Long noncoding RNAs (lncRNAs), such as LINC00462, HOTAIR, and MALAT1, are significantly upregulated in hepatocellular carcinoma (HCC) tissues. However, lncRNA expression in the serum of HCC patients is still unclear. To identify candidate lncRNAs for HCC diagnosis, we purified exosomal total RNA from the serum of healthy volunteers (controls) and hepatitis, cirrhosis, and HCC patients. To assess the function of lncRNAs, small interfering RNAs and overexpression vectors were designed and cell viability and cell apoptosis assays conducted. The exosomes of the control group had a larger number of lncRNAs with a high amount of alternative splicing compared to hepatic disease patients. qPCR assays showed that lnc-FAM72D-3, lnc-GPR89B-15, lncZEB2-19, and lnc-EPC1-4 are differentially expressed in HCC. Furthermore, the expression level of lnc-EPC1-4 correlated with age. While the expression levels of lnc-GPR89B-15 and lnc-EPC1-4 correlated with serum alpha-fetoprotein level. lnc-FAM72D-3 knockdown decreased cell viability and promoted cell apoptosis, indicating that lnc-FAM72D-3 functions as an oncogene in HCC. In contrast, lnc-EPC1-4 overexpression inhibited cell proliferation and induced cell apoptosis, indicating that it functions as a tumor suppressor gene. Collectively, these findings show that lnc-FAM72D-3 and lnc-EPC1-4 play a novel role that might contribute to hepatocarcinogenesis and identify potential candidate biomarkers for HCC diagnosis.

LINC00689 promotes prostate cancer progression via regulating miR-496/CTNNB1 to activate Wnt pathway

Background

Accumulating evidence has proved the significant influence of long non-coding RNAs (lncRNAs) in cancer formation and development, including PCa.

Methods

The role of LINC00689 in PCa was confirmed by RT-qPCR, MTT, colony formation, flow cytometry, western blot and transwell assays. Besides, the binding ability between LINC00689 and miR-496 was validated by using luciferase reporter assay. Then RT-qPCR, RIP and luciferase reporter and western blot assays were employed to verify the interactions among LINC00689, miR-496 and CTNNB1. Furthermore, the rescuing role of CTNNB1 in Wnt pathway was proved by RT-qPCR, TOP/FOP Flash and western blot assays.

Results

LINC00689 was upregulated in PCa tissues and cells as well as at the terminal stage. Further, knock down of LINC00689 repressed PCa cell proliferation, migration and invasion, and initiated PCa cell apoptosis. Additionally, miR-496 inhibitor and pcDNA3.1/CTNNB1 could neutralize the prohibitive effects of LINC00689 silencing on cell proliferation, migration and invasion, meanwhile, could offset the encouraging role of knocking down LINC00689 in cell apoptosis. Moreover, CTNNB1 upregulation exerted redemptive function in Wnt pathway inhibited by LINC00689 depletion.

Conclusions

To sum up, LINC00689 promotes PCa progression via regulating miR-496/CTNNB1 to activate Wnt pathway, which may contribute to research about new targets for PCa treatment.

LncPRYP4-3 serves as a novel diagnostic biomarker for dissecting subtypes of metabolic associated fatty liver disease by targeting RPS4Y2

Longitudinal studies have improved current diagnostics and management of metabolic associated fatty liver disease (MAFLD) patients by liver biopsy and therapeutic intervention, yet the deficiency of biomarker spectrum for dissecting subtypes largely hinders the symptomatic treatment. We originally enriched serum from peripheral blood of 618 healthy donors (HD) and 580 MAFLD (400 NAFL, 180 NASH) patients according to multiple clinicopathological indicators. Microarray profiling and qRT-PCR were conducted to identify lncRNAs as candidate biomarkers of MAFLD. Then, we analyzed the matching score of the indicated lncRNA with CAP or MAFLD-associated pathological parameters as well. Additionally, we took advantage of interaction network together with gene expression profiling analysis to further explore the underlying target genes of the identified lncRNA. Herein, we found CAP in nearly all of the NAFL (399/400) and NASH (179/180) patients was higher than that in the HDs (611/618). The differentially expressed lncRNAs were involved in multiple metabolic or immunologic processes by regulating MAFLD-associated pathways. Of them, serum lncPRYP4-3 was identified as a novel candidate biomarker of MAFLD, which was further confirmed by correlation analysis with clinical indicators. Thereafter, we deduced PRS4Y2 was a candidate target of lncPRYP4-3 and mediated the dysfunction in NAFL and NASH patients. Serum lncPRYP4-3 served as a novel biomarker of MAFLD and helped distinguish the subtypes and benefit precise intervention therapy. Our findings also provided overwhelming new evidence for the alteration in biological processes and gene ontology in MAFLD patients.

Silencing Long Non-coding RNA LINC01224 Inhibits Hepatocellular Carcinoma Progression via MicroRNA-330-5p-Induced Inhibition of CHEK1

Hepatocellular carcinoma (HCC) accounts for approximately 85%–90% of primary liver cancers. Based on in silico analysis, differentially expressed long non-coding RNA (lncRNA) LINC01224 in HCC, the downstream microRNA (miRNA) miR-330-5p, and its target gene checkpoint kinase 1 (CHEK1) were selected as research subjects. Herein, this study was designed to evaluate their interaction effects on the malignant phenotypes of HCC cells. LINC01224 and CHEK1 were upregulated and miR-330-5p was downregulated in HCC cells. miR-330-5p shared negative correlations with LINC01224 and CHEK1, and LINC01224 shared a positive correlation with CHEK1. Notably, LINC01224 could specifically bind to miR-330-5p, and CHEK1 was identified as a target gene of miR-330-5p. When LINC01224 was silenced or miR-330-5p was elevated, the sphere and colony formation abilities and proliferative, migrative, and invasive potentials of HCC cells were diminished, while cell cycle arrest and apoptosis were enhanced. Moreover, LINC01224 induced HCC progression in vitro and accelerated tumor formation in nude mice by increasing CHEK1 expression. The key findings of the present study demonstrated that silencing LINC01224 could downregulate the expression of CHEK1 by competitively binding to miR-330-5p, thus inhibiting HCC progression. This result highlights the LINC01224/miR-330-5p/CHEK1 axis as a novel molecular mechanism involved in the pathology of HCC.

Long noncoding LINC01551 promotes hepatocellular carcinoma cell proliferation, migration, and invasion by acting as a competing endogenous RNA of microRNA-122-5p to regulate ADAM10 expression

Hepatocellular carcinoma (HCC) is a severe disease with high mortality in the world. It has been shown that long noncoding RNA (lncRNA) might play a role in HCC. The aim of the present study was to identify the role of long intergenic noncoding RNA 01551 (LINC01551) in the HCC development and explore the underlying mechanism of LINC01551/miR-122-5p/ADAM10 axis. The differentially expressed lncRNAs associated with HCC were screened out by a microarray analysis. The expression of LINC01551, miR-122-5p, and ADAM10 was determined in HCC tissues and cells. The potential miRNA (miR-122-5p) regulated by LINC01551 was explored, and the target relationship between miR-122-5p and ADAM10 was confirmed. To evaluate the effect of LINC01551 and miR-122-5p on proliferation, migration, invasion, and apoptosis of HCC, different plasmids were delivered into MHCC97-H cells. High expression of LINC01551 and ADAM10 yet low-expression of miR-122-5p were revealed in HCC tissues and cells. Overexpression of miR-122-5p could downregulate ADAM10. Biological prediction websites and fluorescence in situ hybridization assay verified that LINC01551 was mainly expressed in the cytoplasm. Silencing LINC01551 reduced HCC cell viability, proliferation, migration, invasion, and cell cycle entry yet induce cell apoptosis. Upregulation of LINC01551 increased its ability of competitively binding to miR-122-5p, thus reducing miR-122-5p and upregulating ADAM10 expression, as well as promoting the proliferative, migrative, and invasive ability. Taken together the results, it is highly possible that LINC01551 functions as an competing endogenous RNA (ceRNA) to regulate the miRNA target ADAM10 by sponging miR-122-5p and therefore promotes the development of HCC, highlighting a promising competitive new target for the HCC treatment.

Comprehensive analysis of competing endogenous RNA network and 3-mRNA signature predicting survival in papillary renal cell cancer

Long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNAs) to exert significant roles in regulating the expression of mRNAs by sequestering and binding miRNAs. To elucidate the functional roles and regulatory mechanism of lncRNAs in papillary renal cell cancer (pRCC), we conducted a comprehensive analysis of ceRNA network and constructed a mRNA signature to predict prognosis of pRCC.We collected mRNAs and lncRNAs expression profiles of 289 pRCC samples and 32 normal renal tissues, and miRNA expression profiles of 292 pRCC samples and 34 normal samples from The Cancer Genome Atlas (TCGA) database. Differential expressions of RNAs were evaluated by the "edgeR" package in R. Functional enrichment analysis of DEmRNA was performed by DAVID 6.8 and KEGG, while PPI network of top 200 DEmRNAs was conducted using the STRING database. The univariate and multivariate Cox regression were conducted to figure out the candidate DEmRNAs with predictive values in prognosis. Receiver operator characteristic (ROC) curve estimation was performed to achieve the area under the curve (AUC) of the ROC curve to judge mRNA-associated prognosic model. A ceRNA network was established relying on the basis of combination of lncRNA-miRNA interactions and miRNA-mRNA interactions.A total of 1928 DEmRNAs, 981 DElncRNAs, and 52 DEmiRNAs were identified at significance level of |log2Fold Change |>2 and adjusted P-value < .01. A 3-mRNA signatures consisting of ERG, RRM2, and EGF was constructed to predict survival in pRCC. Moreover, a pRCC-associated ceRNA network was constructed, with 57 lncRNAs, 11 miRNAs, and 28 mRNAs.Our study illustrated the regulatory mechanism of ceRNA network in papillary renal cancer. The identified mRNA signatures could be used to predict survival of pRCC.

Comprehensive analysis of a ceRNA network reveals potential prognostic cytoplasmic lncRNAs involved in HCC progression

The aberrant expression of long noncoding RNAs (lncRNAs) has drawn increasing attention in the field of hepatocellular carcinoma (HCC) biology. In the present study, we obtained the expression profiles of lncRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs) in 371 HCC tissues and 50 normal tissues from The Cancer Genome Atlas (TCGA) and identified hepatocarcinogenesis‐specific differentially expressed genes (DEGs, log fold change ≥ 2, FDR < 0.01), including 753 lncRNAs, 97 miRNAs, and 1,535 mRNAs. Because the specific functions of lncRNAs are closely related to their intracellular localizations and because the cytoplasm is the main location for competitive endogenous RNA (ceRNA) action, we analyzed not only the interactions among these DEGs but also the distributions of lncRNAs (cytoplasmic, nuclear or both). Then, an HCC‐associated deregulated ceRNA network consisting of 37 lncRNAs, 10 miRNAs, and 26 mRNAs was constructed after excluding those lncRNAs located only in the nucleus. Survival analysis of this network demonstrated that 15 lncRNAs, 3 miRNAs, and 16 mRNAs were significantly correlated with the overall survival of HCC patients (p < 0.01). Through multivariate Cox regression and lasso analysis, a risk score system based on 13 lncRNAs was constructed, which showed good discrimination and predictive ability for HCC patient survival time. This ceRNA network‐construction approach, based on lncRNA distribution, not only narrowed the scope of target lncRNAs but also provided specific candidate molecular biomarkers for evaluating the prognosis of HCC, which will help expand our understanding of the ceRNA mechanisms involved in the early development of HCC.

Targeting PI3K in cancer: mechanisms and advances in clinical trials

Phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is one of the most important intracellular pathways, which can be considered as a master regulator for cancer. Enormous efforts have been dedicated to the development of drugs targeting PI3K signaling, many of which are currently employed in clinical trials evaluation, and it is becoming increasingly clear that PI3K inhibitors are effective in inhibiting tumor progression. PI3K inhibitors are subdivided into dual PI3K/mTOR inhibitors, pan-PI3K inhibitors and isoform-specific inhibitors. In this review, we performed a critical review to summarize the role of the PI3K pathway in tumor development, recent PI3K inhibitors development based on clinical trials, and the mechanisms of resistance to PI3K inhibition.

Emerging roles of long non-coding RNAs in tumor metabolism

Compared with normal cells, tumor cells display distinct metabolic characteristics. Long non-coding RNAs (lncRNAs), a large class of regulatory RNA molecules with limited or no protein-coding capacity, play key roles in tumorigenesis and progression. Recent advances have revealed that lncRNAs play a vital role in cell metabolism by regulating the reprogramming of the metabolic pathways in cancer cells. LncRNAs could regulate various metabolic enzymes that integrate cell malignant transformation and metabolic reprogramming. In addition to the known functions of lncRNAs in regulating glycolysis and glucose homeostasis, recent studies also implicate lncRNAs in amino acid and lipid metabolism. These observations reveal the high complexity of the malignant metabolism. Elucidating the metabolic-related functions of lncRNAs will provide a better understanding of the regulatory mechanisms of metabolism and thus may provide insights for the clinical development of cancer diagnostics, prognostics and therapeutics.

Serum and exosome long non coding RNAs as potential biomarkers for hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most aggressive cancers, with limited new diagnostic and therapeutic measures. This study aimed to investigate the utility of specific serum and exosome lncRNAs as biomarkers for early diagnosis of HCC.

Methods: The relative expression levels of eight selected lncRNAs in serum were evaluated by quantitative reverse transcription-PCR (qRT-PCR) in the training and validation sets of HCC patients and matched healthy controls. Additionally, the stability, specificity and diagnostic efficiency of these lncRNAs were evaluated to determine their potential as biomarkers. The levels of the final validated lncRNAs in exosome and urine samples of 15 HCC patients and 15 healthy controls were examined for source and path analysis.

Results: LINC00161 was significantly upregulated in serum samples of HCC patients and showed excellent stability and specificity (P< 0.001, fold change=2.85). The area under the receiver operating characteristic (ROC) curve of the validated lncRNA signature was 0.794 (95% CI, 0.712-0.877). LINC00161 expression was detected in serum exosome, exosome-free, and urine samples, and its levels in serum exosome were upregulated in patients with HCC as compared to controls (P= 0.011, fold change=4.27).

Conclusions: Our results indicated that circulating exosomal LINC00161 in serum may be a novel biomarker for HCC. LINC00161 is derived from exosomes into serum and may at least be partly metabolized through urine.

Linc00462 promotes pancreatic cancer invasiveness through the miR-665/TGFBR1-TGFBR2/SMAD2/3 pathway

Emerging evidence has identified that long non-coding RNAs (lncRNAs) may play an important role in the pathogenesis of many cancers, pancreatic cancer (PC) included. However, the role of linc00462 in PC remains unclear. The aim of our present study was to investigate the potential functions of linc00462 in PC and to identify the underlying mechanisms of action. CCK8 assay, transwell assay, cell cycle assay, cell apoptosis assay, EdU assay, western blot assay, cell adhesion assay, HE staining, IF staining, ELISA assay, vivo growth and metastasis assay, and colony formation assay were performed. We demonstrated that OSM mediated up-regulation of linc00462 promoted cell proliferation by accelerating cell cycle process and inhibiting cell apoptosis and adhesion in vitro, enhanced cell migration and invasion by accelerating EMT process, promoted tumor growth and matastasis in vivo and was associated with large tumor size, poor tumor differentiation, TNM stage and distant metastasis in patients of PC. In addition, we demonstrated that linc00462 was a target of miR-665. Linc00462 overexpression enhanced the expression levels of TGFBR1 and TGFBR2, and thus activated the SMAD2/3 pathway in PC cells. In conclusion, linc00462/miR-665/TGFBR1/2 regulatory network may shed light on tumorigenesis in PC.

Behind the curtain of non-coding RNAs; long non-coding RNAs regulating hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most common and aggressive cancers worldwide. HCC is the fifth common malignancy in the world and the second leading cause of cancer death in Asia. Long non-coding RNAs (lncRNAs) are RNAs with a length greater than 200 nucleotides that do not encode proteins. lncRNAs can regulate gene expression and protein synthesis in several ways by interacting with DNA, RNA and proteins in a sequence specific manner. They could regulate cellular and developmental processes through either gene inhibition or gene activation. Many studies have shown that dysregulation of lncRNAs is related to many human diseases such as cardiovascular diseases, genetic disorders, neurological diseases, immune mediated disorders and cancers. However, the study of lncRNAs is challenging as they are poorly conserved between species, their expression levels aren’t as high as that of mRNAs and have great interpatient variations. The study of lncRNAs expression in cancers have been a breakthrough as it unveils potential biomarkers and drug targets for cancer therapy and helps understand the mechanism of pathogenesis. This review discusses many long non-coding RNAs and their contribution in HCC, their role in development, metastasis, and prognosis of HCC and how to regulate and target these lncRNAs as a therapeutic tool in HCC treatment in the future.