microRNA-1914, which is regulated by lncRNA DUXAP10, inhibits cell proliferation by targeting the GPR39-mediated PI3K/AKT/mTOR pathway in HCC

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.

miR-769-3p inhibits cellular proliferation of KSHV-infected SH-SY5Y cells through targeting mTOR

The infection by Kaposi's sarcoma-associated herpesvirus (KSHV) is one of the most common causes of death in AIDS patients. Our studies have found that KSHV can infect SH-SY5Y cells (named SK-RG) in vivo and mTOR was up-regulated, which results in remarkable enhancement of cell proliferation, migration. But the regulatory role of mTOR in KSHV infected neurons has not yet been fully elucidated. Here, we find that miR-769-3p is decreased in SK-RG cells, which can exert anti-KSHV effect through negatively regulating the expression of mTOR. The knockdown of mTOR or overexpress of miR-769-3p decreased the proliferation, migration ability and cell cycle related protein of SK-RG cells, and the expression of KSHV related genes. In contrast, activating mTOR function by 3BDO treatment weakened the cellular behaviors of miR-769-3p overexpressing cells. Meanwhile, overexpressed miR-769-3p and rapamycin showed a shared inhibition trend in the effects on cell proliferation and motility. Our data indicated that miR-769-3p can inhibit cell proliferation and migration by down regulating mTOR in KSHV infected SH-SY5Y cells, and can be a candidate molecule for anti-KSHV therapy.

Signaling pathway mechanisms of neurological diseases induced by G protein-coupled receptor 39

BACKGROUND

G protein-coupled receptor 39 (GPR39) is a transmembrane zinc receptor with two splice variants, which belongs to the G-protein-coupled receptor growth hormone-releasing peptide family. Its expression is induced by zinc, which activates GPR39, and its activation mediates cell proliferation, ion homeostasis, and anti-inflammatory, antioxidant, and other pathophysiological effects via different signaling pathways.

AIMS

The article reviews the latest literature in this field. In particular, the role of GPR39 in nervous system is discussed.

MATERIALS AND METHODS

GPR39 can be a promising target in neurological diseases for targeted therapy, which will help doctors overcome the associated problems.

DISCUSSION

GPR39 is expressed in vivo at several sites. Increasing evidence suggests that GPR39 plays an important role as a neuroprotective agent in vivo and regulates various neurological functions, including neurodegeneration, neuroelectrophysiology, and neurovascular homeostasis.

CONCLUSION

This review aims to provide an overview of the functions, signal transduction pathways, and pathophysiological role of GPR39 in neurological diseases and summarize the GPR39 agonists that have been identified in the recent years.

A prognostic risk model for ovarian cancer based on gene expression profiles from gene expression omnibus database

This study explored prognostic genes of ovarian cancer and built a prognostic model based on these genes to predict patient's survival, which is of great significance for improving treatment of ovarian cancer. GSE26712 dataset was downloaded from Gene Expression Omnibus database as training set, while OV-AU dataset was downloaded from ICGC website as validation set. All genes in GSE26712 were analyzed by univariate Cox regression, Lasso regression, and multivariate Cox regression analyses. Then prognosis-related feature genes were screened to construct a multivariate risk model. Meanwhile, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed on samples in the high/low-risk groups using Gene Set Enrichment Analysis (GSEA) software. Finally, survival curve and receiver operating characteristic curve were drawn to verify the validity of the model. Ten feature genes related to prognosis of ovarian cancer were obtained: CMTM6, COLGALT1, F2R, GPR39, IGFBP3, RNF121, MTMR9, ORAI2, SNAI2, ZBTB16. GSEA enrichment analysis showed that there were notable differences in biological pathways such as gap junctions and homologous recombination between the high/low-risk groups. Through further verification of training set and validation set, the 10-gene prognostic model was found to be effective for the prognosis of ovarian cancer patients. In this study, we constructed a 10-gene prognostic model which predicted the prognosis of ovarian cancer patients well by integrating clinical prognostic parameters. It may have certain reference value for subsequent clinical treatment research of ovarian cancer patients and help in clinical treatment decision-making.

Long non-coding RNAs (lncRNAs) in hepatocellular carcinoma progression: Biological functions and new therapeutic targets

Liver is an important organ in body that performs vital functions such as detoxification. Liver is susceptible to development of cancers, and hepatocellular carcinoma (HCC) is among them. 75-85% of liver cancer cases are related to HCC. Therefore, much attention has been directed towards understanding factors mediating HCC progression. LncRNAs are epigenetic factors with more than 200 nucleotides in length located in both nucleus and cytoplasm and they are promising candidates in cancer therapy. Directing studies towards understanding function of lncRNAs in HCC is of importance. LncRNAs regulate cell cycle progression and growth of HCC cells, and they can also induce/inhibit apoptosis in tumor cells. LncRNAs affect invasion and metastasis in HCC mainly by epithelial-mesenchymal transition (EMT) mechanism. Revealing the association between lncRNAs and downstream signaling pathways in HCC is discussed in the current manuscript. Infectious diseases can affect lncRNA expression in mediating HCC development and then, altered expression level of lncRNA is associated with drug resistance and radio-resistance. Biomarker application of lncRNAs and their role in prognosis and diagnosis of HCC are also discussed to pave the way for treatment of HCC patients.

A diagnostic miRNA panel to detect recurrence of ovarian cancer through artificial intelligence approaches

BACKGROUND

Ovarian Cancer (OC) is the deadliest gynecology malignancy, whose high recurrence rate in OC patients is a challenging object. Therefore, having deep insights into the genetic and molecular mechanisms of OC recurrence can improve the target therapeutic procedures. This study aimed to discover crucial miRNAs for the detection of tumor recurrence in OC by artificial intelligence approaches.

METHOD

Through the ANOVA feature selection method, we selected 100 candidate miRNAs among 588 miRNAs. For their classification, a deep-learning model was employed to validate the significance of the candidate miRNAs. The accuracy, F1-score (high-risk), and AUC-ROC of classification test data based on the 100 miRNAs were 73%, 0.81, and 0.65, respectively. Association rule mining was used to discover hidden relations among the selected miRNAs.

RESULT

Five miRNAs, including miR-1914, miR-203, miR-135a-2, miR-149, and miR-9-1, were identified as the most frequent items among high-risk association rules. The identified miRNAs may target genes/proteins involved in epithelial-mesenchymal transition (EMT), resistance to therapy, and cancer stem cells; being responsible for the heterogeneity and plasticity of the tumor. Our conclusion presents mir-1914 as the significant candidate miRNA and the most frequent item. Current knowledge indicates that the dysregulated miR-1914 may function as a tumor suppressor or oncogene in the development of cancer.

CONCLUSION

These candidate miRNAs can be considered a powerful tool in the diagnosis of OC recurrence. We hypothesize that mir-1914 might open a new line of research in the realm of managing the recurrence of OC and could be a significant factor in triggering OC recurrence.

MicroRNA-mediated regulation of key signaling pathways in hepatocellular carcinoma: A mechanistic insight

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. The molecular pathogenesis of HCC varies due to the different etiologies and genotoxic insults. The development of HCC is characterized by complex interactions between several etiological factors that result in genetic and epigenetic changes in proto-onco and/or tumor suppressor genes. MicroRNAs (miRNAs) are short non-coding RNAs that also can act as oncomiRs or tumor suppressors regulating the expression of cancer-associated genes post-transcriptionally. Studies revealed that several microRNAs are directly or indirectly involved in cellular signaling, and dysregulation of those miRNAs in the body fluids or tissues potentially affects key signaling pathways resulting in carcinogenesis. Therefore, in this mini-review, we discussed recent progress in microRNA-mediated regulation of crucial signaling networks during HCC development, concentrating on the most relevant ones such as PI3K/Akt/mTOR, Hippo-YAP/TAZ, and Wnt/β-catenin, which might open new avenues in HCC management.

Involvement of microRNAs and their potential diagnostic, therapeutic, and prognostic role in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for 85%-90% of primary liver cancer. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by targeting the 3'UTR of mRNA. Abnormal expression and regulation of miRNAs are involved in the occurrence and progression of HCC, and miRNAs can also play a role in the diagnosis and treatment of HCC as oncogenes or tumor suppressors.

METHODS

In the past decades, a large number of studies have shown that miRNAs play an essential regulatory role in HCC and have potential as biomarkers for HCC. We reviewed the literature to summarize these studies.

RESULTS

By reviewing the literature, we retrospected the roles of miRNAs in the development, diagnosis, treatment, and prognosis of HCC, and put forward prospects for the further research on miRNAs in the precision treatment of HCC.

CONCLUSION

MicroRNAs are important regulators and biomarkers in the occurrence, progression, outcome, and treatment of HCC, and can provide new targets and strategies for improving the therapeutic effect of HCC.

Hypoxia-driven miR-1307-3p promotes hepatocellular carcinoma cell proliferation and invasion by modulating DAB2 interacting protein

Hypoxia is a common feature of the solid tumor microenvironment that is presented as poor clinical outcomes in multiple tumor types, including HCC. Hypoxia stabilizes HIF-1α/HIF-2α, which then moves into the nucleus and binds with HIF-1β to form a transcription complex, thereby promoting the transcription of target genes, including mRNAs, miRNAs and lncRNAs to exert their biological functions. Here, through a series of functional assay, including hypoxia culture, MTT, colony-formation, Transwell, qRT-PCR and western blot, we confirmed that miR-1307-3p, as a novel hypoxia-responsive factor, can be directly transcribed by HIF-1α rather than HIF-2α. Hypoxia-driven miR-1307-3p facilitated proliferation and invasion of HCC cells via repressing DAB2IP. Moreover, under hypoxia microenvironment, DAB2IP, as a direct target of miR-1307-3p, was down-regulated to activate AKT/mTOR signaling to further maintain the expression level of HIF-1α, thereby forming a feedback loop between HIF-1α/miR-1307-3p and DAB2IP. Targeting miR-1307-3p/DAB2IP axis also modulated tumor growth and metastasis in vivo. In summary, there exists a feedback loop between HIF-1α/miR-1307-3p and DAB2IP in HCC. Targeting a vicious feedback loop between HIF-1α/miR-1307-3p and DAB2IP may be a promising strategy to combat HCC.

Cleavage stimulation factor 2 promotes malignant progression of liver hepatocellular carcinoma by activating phosphatidylinositol 3'-kinase/protein kinase B/mammalian target of rapamycin pathway

Liver hepatocellular carcinoma (LIHC) is the most common type, comprising 75-85% of all liver malignancies. We investigated the roles of cleavage stimulation factor 2 (CSTF2) in LIHC and explored the underlying mechanisms. CSTF2 expression and its association with LIHC patient survival probability were analyzed with The Cancer Genome Atlas. CSTF2 expression in LIHC cells was assessed using western blot and quantitative real-time PCR. Alterations in CSTF2 expression were induced by cell transfection. Cell colony formation, apoptosis, proliferation, invasion, and migration were assessed using colony formation, flow cytometry, 5-ethynyl-2'-deoxyuridine, and transwell assays. Pathway enrichment analysis was performed using gene set enrichment analysis (GSEA). The expression of apoptosis-, metastasis-, and pathway-associated factors was determined via western blot. The pathway rescue assay was further performed using 740Y-P or Wortmannin. CSTF2 upregulation was observed in LIHC tissues and cells. Patients with high CSTF2 expression had a lower probability of overall survival. CSTF2 overexpression enhanced colony formation, proliferation, invasion and migration, while repressing apoptosis in LIHC cells. GSEA revealed that CSTF2 was mainly enriched in the phosphatidylinositol 3'-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Western blot analysis proved that CSTF2 overexpression activated this pathway. CSTF2 knockdown yielded the opposite effects. 740Y-P, a PI3K activator, reversed the CSTF2 knockdown-triggered effects on cell proliferation, apoptosis, invasion, and migration. Moreover, Wortmannin, a PI3K inhibitor, also reversed the CSTF2 overexpression-induced effects on cell proliferation, apoptosis, invasion, and migration. These results indicated that CSTF2 overexpression might exacerbate the malignant phenotypes of LIHC cells via activation of PI3K/AKT/mTOR pathway.

The LncRNA DUXAP10 Could Function as a Promising Oncogene in Human Cancer

Cancer is one of the most prevalent and deadliest diseases globally, with an increasing morbidity of approximately 14 million new cancer cases per year. Identifying novel diagnostic and prognostic biomarkers for cancers is important for developing cancer therapeutic strategies and lowering mortality rates. Long noncoding RNAs (lncRNAs) represent a group of noncoding RNAs of more than 200 nucleotides that have been shown to participate in the development of human cancers. The novel lncRNA DUXAP10 was newly reported to be abnormally overexpressed in several cancers and positively correlated with poor clinical characteristics of cancer patients. Multiple studies have found that DUXAP10 widely regulates vital biological functions related to the development and progression of cancers, including cell proliferation, apoptosis, invasion, migration, and stemness, through different molecular mechanisms. The aim of this review was to recapitulate current findings regarding the roles of DUXAP10 in cancers and evaluate the potential of DUXAP10 as a novel biomarker for cancer diagnosis, treatment, and prognostic assessment.

Anticancer effect of myristicin on hepatic carcinoma and related molecular mechanism

CONTEXT

Myristicin is a natural active compound that has inflammatory, antimicrobial and anti-proliferative properties. Yet, its effect on hepatic carcinoma has not been investigated.

OBJECTIVE

To explore the role and related molecular mechanism of myristicin in hepatic carcinoma in vitro.

MATERIALS AND METHODS

Human hepatic carcinoma cell lines (Huh-7 and HCCLM3 cells) were treated with different concentrations of myristicin (0.5, 1 and 5 mM) for 24, 48 and 72 h. Then, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay (MTT), flow cytometer (FCM) analysis and transwell assay were performed to determine cell proliferation, apoptosis and migration/invasion, respectively. Protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax), E-cadherin, N-cadherin and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway-related proteins were detected using Western blot assay. Gene expression was determined using quantitative real time-polymerase chain reaction (qRT-PCR).

RESULTS

Myristicin inhibited cell proliferation and induced apoptosis in Huh-7 and HCCLM3 cells; suppressed cell migration and invasion ability, and increased E-cadherin expression and decreased N-cadherin expression, thereby inhibiting epithelial-mesenchymal transition (EMT). Finally, the findings indicated that myristicin decreased phosphorylated (p)-mTOR and p-AKT expression at the protein level.

DISCUSSION AND CONCLUSIONS

Myristicin exerts an efficient therapeutic effect on hepatic carcinoma by suppressing PI3K/Akt/mTOR signalling pathway; thus, it may be used as a new potential drug for hepatic carcinoma treatment.

MicroRNA-4317 suppresses the progression of hepatocellular carcinoma by targeting ZNF436-mediated PI3K/AKT signaling pathway

Hepatocellular carcinoma (HCC) is a major type of liver cancer with high mortality, which is a prevalent common cancer in the world. Aberrant miRNAs contribute to the progression and development of HCC. Currently, our study demonstrated that miR-4317 was decreased in HCC patient samples tissues and HCC cell lines, which was related to poor clinical features, including tumor size, advanced TNM stage and vascular invasion. Furthermore, we confirmed that miR-4317 suppressed cell viability, proliferation, invasion and migration through loss- and gain-of-function experiment in vitro. In addition, miR-4317 inhibited tumor growth in vivo experiment. Luciferase reporter assays confirmed that ZNF436 was a direct target of miR-4317. Restoration of ZNF436 reversed the role of miR-4317 on HCC. ZNF436 expression was increased in HCC tissues and cell lines, which was negatively correlated with miR-4317 expression. ZNF436 overexpression obviously promoted the cell proliferation, viability, invasion and migration of HCC cells. ZNF436 mediated the regulatory function of miR-4317 on PI3K/AKT pathway. Overall, our data suggest that miR-4317 is a novel tumor suppressor to suppress HCC progression through PI3K/AKT pathway by targeting ZNF436, and may serve as a prognostic biomarker and therapeutic target for HCC.

Hsa_circ_0007059 sponges miR-421 to repress cell growth and stemness in hepatocellular carcinoma by the PTEN-AKT/mTOR pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is a substantial health concern worldwide. Increasing studies have suggested that circle RNAs (circRNAs) function as new regulators in HCC progression. The present work explored the role of hsa_circ_0007059 (circ_0007059) in the developing process of hepatocarcinogenesis.

METHODS

The circ_0007059 level in HCC was determined by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and northern blot. Its biological role in HCC cells was assessed using 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry, Transwell, sphere formation and western blotting analyses. Bioinformatics analysis, luciferase reporter, and RNA immunoprecipitation (RIP) assays were used to test the regulatory mechanisms of circ_0007059.

RESULTS

Our results revealed that circ_0007059 expression was downregulated in HCC samples and cells. Moreover, circ_0007059 overexpression inhibited HCC cell proliferation, migration, invasion, and stem cell-like property, and strengthened cell apoptosis. In mechanism, circ_0007059 suppressed AKT/mTOR pathway by positively regulating phosphatase and tensin homolog (PTEN) expression. Additionally, circ_0007059 acted as a positive regulator of PTEN through controlling the availability of miR-421. Rescue assays demonstrated that PTEN knockdown or SC79 (AKT agonist) eliminated the effect of circ_0007059 on HCC cell phenotypes.

CONCLUSION

Circ_0007059 sponges miR-421 to inhibit oncogenic cellular process in HCC by mediating the PTEN-AKT/mTOR pathway.

LncRNA DUXAP10 Upregulation and the Hedgehog Pathway Activation Are Critically Involved in Chronic Cadmium Exposure-Induced Cancer Stem Cell-Like Property

Cadmium (Cd) is a well-known lung carcinogen. However, the mechanism of Cd carcinogenesis remains to be clearly defined. Cd has been shown to act as a weak mutagen, suggesting that it may exert tumorigenic effect through nongenotoxic ways, such as epigenetic mechanisms. Long noncoding RNAs (lncRNAs) refer to RNA molecules that are longer than 200 nucleotides in length but lack protein-coding capacities. Regulation of gene expressions by lncRNAs is considered as one of important epigenetic mechanisms. The goal of this study is to investigate the mechanism of Cd carcinogenesis focusing on the role of lncRNA dysregulations. Cd-induced malignant transformation of human bronchial epithelia BEAS-2B cells was accomplished by a 9-month low-dose Cd (CdCl2, 2.5 µM) exposure. The Cd-exposed cells formed significantly more colonies in soft agar, displayed cancer stem cell (CSC)-like property, and formed tumors in nude mice. Mechanistically, chronic low-dose Cd exposure did not cause significant genotoxic effects but dysregulated lncRNA expressions. Further Q-PCR analysis confirmed the significant upregulation of the oncogenic lncRNA DUXAP10 in Cd-transformed cells. DUXAP10 knockdown in Cd-transformed cells significantly reduced their CSC-like property. Further mechanistic studies showed that the Hedgehog pathway is activated in Cd-transformed cells and inhibition of this pathway reduces Cd-induced CSC-like property. DUXAP10 knockdown caused the Hedgehog pathway inactivation in Cd-transformed cells. Furthermore, Pax6 expression was upregulated in Cd-transformed cells and Pax6 knockdown significantly reduced their DUXAP10 levels and CSC-like property. In summary, these findings suggest that the lncRNA DUXAP10 upregulation may play an important role in Cd carcinogenesis.

RNA sequencing identifies two novel liver-specific long noncoding RNAs with potential diagnostic value in hepatocellular carcinoma

Aim: To explore the expression profiles of long noncoding RNAs (lncRNAs) and identify novel lncRNAs as biomarkers for early diagnosis and therapy of hepatocellular carcinoma (HCC). Materials & methods: Expression profiles of lncRNAs and mRNAs in five paired HCC and adjacent normal tissues were obtained by RNA sequencing. Eight lncRNAs, including two novel liver-specific lncRNAs (NONHSAT059247.2 and NONHSAT013897.2), were validated in another 74 pairs of HCC and adjacent normal tissues by quantitative reverse transcription PCR. Results: The results of quantitative reverse transcription PCR showed that NONHSAT252133.1, NONHSAT112116.2 and NONHSAT242657.1 were significantly upregulated in HCC tissues, whereas NONHSAT169790.1, NONHSAT059247.2 and NONHSAT013897.2 were significantly downregulated. Two liver-specific lncRNAs demonstrated excellent diagnostic performance: NONHSAT059247.2 (area under the curve = 0.941, 95% CI: 0.902-0.979, p < 0.0001), NONHSAT013897.2 (area under the curve = 0.944, 95% CI: 0.906-0.983, p < 0.0001). Conclusion: The liver-specific lncRNAs NONHSAT059247.2 and NONHSAT013897.2, may provide new biomarkers for the future study on diagnosis, therapy and mechanisms of HCC.

Long non-coding RNA LINC01116 is activated by EGR1 and facilitates lung adenocarcinoma oncogenicity via targeting miR-744-5p/CDCA4 axis

Background

Lung adenocarcinoma (LAD) is one of the most frequently diagnosed pathological categories of human lung cancer. Nevertheless, the link between long non-coding RNA (lncRNA) LINC01116 and LAD remains poorly investigated.

Methods

QRT-PCR and western blot were applied for quantifying the expression of RNAs and proteins. Both functional experiments assays in vitro and xenografts model in vivo were implemented for analyzing LINC01116 function in LAD while molecular relationship among RNAs was investigated via mechanism experiments.

Results

LINC01116 was expressed at an abnormally high level in LAD, which was induced by transcription activator EGR1. LINC01116 depletion restrained proliferation, migration and invasion, yet facilitated apoptosis of LAD cells. MiR-744-5p could bind to LINC01116. MiR-744-5p inhibitor reversed the inhibitory effects of silencing LINC01116 on LAD malignant behaviors. In addition, cell division cycle-associated protein 4 (CDCA4) shared binding sites with miR-744-5p. Silencing LINC01116 elicited decline in CDCA4 mRNA and protein levels. Moreover, CDCA4 up-regulation could counteract the biological effects of LINC01116 knockdown on LAD cells.

Conclusion

Our data revealed that LINC01116 promoted malignant behaviors of LAD cells by targeting miR-744-5p/CDCA4 axis, implying the theoretical potential of LINC01116 as a novel target for LAD treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01994-w.

Epigenetic Regulation of Hepatocellular Carcinoma Progression through the mTOR Signaling Pathway

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is an aggressive tumor with a high mortality rate because of the limited systemic and locoregional treatment modalities. The development and progression of HCC depend on epigenetic changes that result in the activation or inhibition of some signaling pathways. The mTOR signaling pathway is essential for many pathophysiological processes and is considered a major regulator of cancer. Increasing evidence has shown that epigenetics plays a key role in HCC biology by regulating the mTOR signaling pathway. Therefore, epigenetic regulation through the mTOR signaling pathway to diagnose and treat HCC will become a very promising strategy.

Long noncoding RNA DUXAP10 promotes the stemness of glioma cells by recruiting HuR to enhance Sox12 mRNA stability

Long noncoding RNA (lncRNA) DUXAP10 has been shown to act as an oncogene in various tumors; however, its roles in glioma progression have never been established. Here, we show that DUXAP10 is overexpressed in glioma tissues and cells. Loss of function experiments reveal that DUXAP10 knockdown has little effects on glioma cell viability, but significantly reduces the stemness of glioma cells, which is characterized as the decrease of stemness marker expression, tumor sphere-forming ability, and ALDH activity. RNA immunoprecipitation and immunofluorescence assays indicate that DUXAP10 can directly interact with HuR protein and suppress the cytoplasm-nuclear translocation of HuR, which subsequently enhances Sox12 mRNA stability in cytoplasm and thus increases Sox12 expression. Further rescuing experiments show that the HuR/Sox12 axis is responsible for DUXAP10-mediated effects on glioma cell stemness.

The Zinc-Sensing Receptor GPR39 in Physiology and as a Pharmacological Target

The G-protein coupled receptor GPR39 is abundantly expressed in various tissues and can be activated by changes in extracellular Zn²⁺ in physiological concentrations. Previously, genetically modified rodent models have been able to shed some light on the physiological functions of GPR39, and more recently the utilization of novel synthetic agonists has led to the unraveling of several new functions in the variety of tissues GPR39 is expressed. Indeed, GPR39 seems to be involved in many important metabolic and endocrine functions, but also to play a part in inflammation, cardiovascular diseases, saliva secretion, bone formation, male fertility, addictive and depression disorders and cancer. These new discoveries offer opportunities for the development of novel therapeutic approaches against many diseases where efficient therapeutics are still lacking. This review focuses on Zn²⁺ as an endogenous ligand as well as on the novel synthetic agonists of GPR39, placing special emphasis on the recently discovered physiological functions and discusses their pharmacological potential.

In vitro and in vivo antitumor effects of lupeol-loaded galactosylated liposomes

Lupeol liposomes, modified with Gal-PEG-DSPE, were developed following a thin-film dispersion method. Then, the morphology, physicochemical properties, and in vitro release properties of those liposomes were investigated. The scanning electron microscopic images showed that most of the liposomes were spherical particles; they were similar in size and uniformly dispersed. Both lupeol liposomes and Gal-lupeol liposomes exhibited an average particle size of about 100 nm. The encapsulation efficiency was greater than 85%. The encapsulation efficiency of lupeol liposome and Gal-lupeol liposome, stored with 15% sucrose as glycoprotein for 6 months, was higher than 80%; although the particle size increased, they remained within 200 nm. The cell-uptake study demonstrated that the Gal-lupeol-liposome uptake efficiency was the highest in HepG2 cells. The HepG2 cells treated with the Gal-lupeol liposomes had higher apoptotic efficiency than the lupeol liposome and free lupeol. After HepG2 cells were treated with Gal-lupeol liposome, the expressions of AKT/mTOR-related proteins (p-AKT308 and p-AKT473) were also significantly reduced than the lupeol-liposome and free lupeol group. The in vivo targeting studies showed that Gal-NR-L exhibited liver-targeting effects on FVB mice. The pharmacodynamic study was performed by transfecting AKT and c-MET via the high-pressure tail vein of FVB mice. After Gal-lupeol-L administration, the liver index and liver weight of mice were less than those non-targeted group. The histopathological study showed that the lobular structure in the mice liver was clearer, the vacuoles were more obvious, and the cytoplasm was more abundant after Gal-lupeol-L administration. Also, the qRT-PCR study showed that AFP, GPC3, and EpCAM mRNA expression levels were significantly lower than those non-targeted lupeol-liposomes.

GPR39 promotes cardiac hypertrophy by regulating the AMPK-mTOR pathway and protein synthesis

Hypertrophic growth of the cardiomyocytes is one of the core mechanisms underlying cardiac hypertrophy. However, the mechanism underlying cardiac hypertrophy remains not fully understood. Here we provided evidence that G protein-coupled receptor 39 (GPR39) promotes cardiac hypertrophy via inhibiting AMP-activated protein kinase (AMPK) signaling. GRP39 expression is overexpressed in hypertrophic hearts of humans and transverse aortic constriction (TAC)-induced cardiac hypertrophy in mice. In neonatal cardiomyocytes, adenovirus-mediated overexpression of GPR39 promoted angiotensin II-induced cardiac hypertrophy, while GPR39 knockdown repressed hypertrophic response. Adeno-associated virus 9-mediated knockdown of GPR39 suppressed TAC-induced decline in fraction shortening and ejection fraction, increase in heart weight and cardiomyocyte size, as well as overexpression of hypertrophic fetal genes. A mechanism study demonstrated that GPR39 repressed the activation of AMPK to activate the mammalian target of rapamycin (mTOR) and ribosomal protein S6 kinase β-1 (S6K1), subsequently promoted de novo protein synthesis. Inhibition of mTOR with rapamycin blocked the effects of GPR39 overexpression on protein synthesis and repressed cardiac hypertrophy. Collectively, our findings demonstrated that GPR39 promoted cardiac hypertrophy via regulating the AMPK-mTOR-S6K1 signaling pathway, and GRP39 can be targeted for the treatment of cardiac hypertrophy.

Long noncoding RNA PICSAR/miR-588/EIF6 axis regulates tumorigenesis of hepatocellular carcinoma by activating PI3K/AKT/mTOR signaling pathway

Accumulating evidence has identified long noncoding RNAs (lncRNAs) as regulators in tumor progression and development. Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA‐PICSAR (p38 inhibited cutaneous squamous cell carcinoma associated lincRNA) on the biological behaviors of HCC. In the present study, we found that PICSAR was upregulated in HCC tissues and cells and correlated with progression and poor prognosis in HCC patients. Gain‐ and loss‐of‐function experiments indicated that PICSAR enhanced cell proliferation, colony formation, and cell cycle progression and inhibited apoptosis of HCC cells. PICSAR could function as a competing endogenous RNA by sponging microRNA (miR)‐588 in HCC cells. Mechanically, miR‐588 inhibited HCC progression and alternation of miR‐588 reversed the promotive effects of PICSAR on HCC cells. In addition, we confirmed that eukaryotic initiation factor 6 (EIF6) was a direct target of miR‐588 in HCC and mediated the biological effects of miR‐588 and PICSAR in HCC, resulting in PI3K/AKT/mTOR pathway activation. Our data identified PICSAR as a novel oncogenic lncRNA associated with malignant clinical outcomes in HCC patients. PICSAR played an oncogenic role by targeting miR‐588 and subsequently promoted EIF6 expression and PI3K/AKT/mTOR activation in HCC. Our results revealed that PICSAR could be a potential prognostic biomarker and therapeutic target for HCC.

Long non-coding RNA ADAMTS9-AS1 exacerbates cell proliferation, migration, and invasion via triggering of the PI3K/AKT/mTOR pathway in hepatocellular carcinoma cells

Although many long non-coding RNAs (lncRNAs) are modulators of biological events in hepatocellular carcinoma (HCC), the potential significance of most lncRNAs in HCC remains to be fully understood. The role of lncRNA ADAMTS9-AS1 in HCC was therefore determined. ADAMTS9-AS1 expression was higher in HCC cell lines compared to normal cells as determined by qPCR analyses. Furthermore, CCK-8, scratch wound healing, transwell migration, and invasion assays suggested that ADAMTS9-AS1 overexpression promoted the proliferation, migration, and invasion in MHCC97-H and HepG2 cells; ADAMTS9-AS1 knockdown showed the opposite results. Based on the results from GEO, the correlation between ADAMTS9-AS1 and PI3K/AKT/mTOR was identified. Thus, an association between ADAMTS9-AS1 and the PI3K/AKT/mTOR signaling pathway was further observed. To confirm the pathway protein levels, p-AKT, PIK3CB, and p-mTOR were selected. Western blot assays suggested that ADAMTS9-AS1 enhanced the expression levels of the three proteins. Because of their close relationship with PI3K/AKT/mTOR, apoptosis- or autophagy-related proteins were further investigated. ADAMTS9-AS1 expression was negatively related with LC3-II, BECN1, and pro-apoptotic Bax, whereas it was positively correlated SQSTM1 and anti-apoptotic Bcl-2 expression. Western blot results suggested that ADAMTS9-AS1 decreased ADAMTS9 expression. Our data revealed that ADAMTS9-AS1 contributed to proliferation, migration, and invasion in HCC cells, likely due to the activation of the PI3K/AKT/mTOR signaling pathway, to influence autophagy and apoptosis. These findings suggest that ADAMTS9-AS1 could serve as a molecular target in HCC treatment.

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.

Orchestration of Intracellular Circuits by G Protein-Coupled Receptor 39 for Hepatitis B Virus Proliferation

Hepatitis B virus (HBV), a highly persistent pathogen causing hepatocellular carcinoma (HCC), takes full advantage of host machinery, presenting therapeutic targets. Here we aimed to identify novel druggable host cellular factors using the reporter HBV we have recently generated. In an RNAi screen of G protein-coupled receptors (GPCRs), GPCR39 (GPR39) appeared as the top hit to facilitate HBV proliferation. Lentiviral overexpression of active GPR39 proteins and an agonist enhanced HBV replication and transcriptional activities of viral promoters, inducing the expression of CCAAT/enhancer binding protein (CEBP)-β (CEBPB). Meanwhile, GPR39 was uncovered to activate the heat shock response, upregulating the expression of proviral heat shock proteins (HSPs). In addition, glioma-associated oncogene homologue signaling, a recently reported target of GPR39, was suggested to inhibit HBV replication and eventually suppress expression of CEBPB and HSPs. Thus, GPR39 provirally governed intracellular circuits simultaneously affecting the carcinopathogenetic gene functions. GPR39 and the regulated signaling networks would serve as antiviral targets, and strategies with selective inhibitors of GPR39 functions can develop host-targeted antiviral therapies preventing HCC.

ZNF521 which is downregulated by miR-802 suppresses malignant progression of Hepatocellular Carcinoma through regulating Runx2 expression

Zinc finger protein 521 (ZNF521) plays an important role in the tumor development and process. However, its regulatory role in hepatocellular carcinoma (HCC) remains unclear. In this study, we demonstrated for the first time that ZNF521 mRNA and protein was down-regulated in HCC tissues and cell lines. Down-regulated ZNF521 expression was significantly associated with malignant prognostic features, including advanced TNM stage and large tumor size. For 5-year survival, ZNF521 served as a potential prognostic marker of HCC patients. Moreover, ZNF521 inhibited cell proliferation, colony formation and cell viability through Runx2 transcriptional inhibition and AKT phosphorylation pathway. Moreover, we demonstrated that ZNF521 expression was regulated by miR-802. In HCC tissues. MiR-802 has an inverse correlation with ZNF521 expression. In conclusion, we demonstrate for the first time that ZNF521 is down-regulated in HCC tissues and inhibits HCC growth through Runx2 transcriptional inhibition and AKT inactivation, which was regulated by miR-802, suggesting the potential therapeutic value for HCC.

Long Noncoding RNA ADAMTS9-AS2 Inhibits the Proliferation, Migration, and Invasion in Bladder Tumor Cells

BACKGROUND

Bladder tumor is the fifth most prevalent tumor in men, yet its pathogenesis remains to be fully identified. Albeit a host of long noncoding RNAs (lncRNA) are emerging as new players involved in bladder tumor, the functions of many lncRNAs are still enigmatic. Reports on the deluge of studies on lncRNA ADAMTS9-AS2 have been convincingly associated with various tumors, but without mention of its roles in bladder tumor. Therefore, the roles of ADAMTS9-AS2 in bladder tumor cells were explored in our study.

MATERIALS AND METHODS

Quantitative real-time PCR assays and bioinformatic tools were applied in bladder tumor cells to identify the ADAMTS9-AS2 and ADAMTS9 expression. Western blot assays were performed to obtain the protein levels of bladder tumor related key molecules. CCK8, clonogenic assay, scratch wound healing, and transwell assays were separately applied to identify the functional roles of ADAMTS9-AS2 on proliferation, migration, and invasion in bladder tumor cells.

RESULTS

First, ADAMTS9-AS2 downregulation in bladder tumor cells was identified. Overexpression and knockdown experiments showed that ADAMTS9-AS2 expression was positively related to ADAMTS9, which is in accordance with the results from GEO database. Second, ADAMTS9-AS2 contributed to the inhibition of proliferation, migration, and invasion in bladder tumor cells. Third, ADAMTS9-AS2 was linked with PI3K/AKT/mTOR pathway related-molecules, several key autophagy, and apoptotic proteins.

CONCLUSION

Conjointly, our findings suggested that ADAMTS9-AS2 might function as a tumor suppressor to restrain the proliferation, migration, and invasion in bladder tumor cells. The potential mechanism of ADAMTS9-AS2 related to PI3K/AKT/mTOR signal pathway was further identified. Of note, we found that ADAMTS9-AS2 has a significant effect on several key autophagy and apoptotic proteins. Therefore, these observations will provide supportive evidence to ADAMTS9-AS2 as a potential biomarker in patients with bladder tumor.

ZKSCAN3 drives tumor metastasis via integrin β4/FAK/AKT mediated epithelial-mesenchymal transition in hepatocellular carcinoma

Background

ZKSCAN3, a zinc-finger transcription factor containing KRAB and SCAN domains, has been reported to be regulated in several human cancers. However, its expression and function in hepatocellular carcinoma (HCC) remains unknown.

Methods

Expression of ZKSCAN3 in HCC was analyzed by western blotting, immunohistochemistry, and real time PCR. Its correlation with the clinicopathological characteristics and prognosis of HCC patients was analyzed. The effects of ZKSCAN3 on the migration and invasion were determined by Transwell assays. The potential downstream targets of ZKSCAN3 and related molecular mechanisms were clarified by Western blot and dual luciferase reporter assay.

Results

In this study, we demonstrated for the first time that ZKSCAN3 mRNA and protein was up-regulated in HCC tissues and cell lines. High ZKSCAN3 expression was significantly associated with poor prognostic features, including advanced TNM stage and vascular invasion. For 5-year survival, ZKSCAN3 served as a potential prognostic marker of HCC patients. Functionally, ZKSCAN3 promoted migration, invasion and EMT progress via directly binding to integrin β4 (ITGB4) promoter and enhanced its expression. Further investigation proved that ITGB4 triggers the focal adhesion kinase (FAK) to activate the AKT signaling pathway. Inactivation of FAK and AKT by their specific inhibitors respectively reversed the effects of ZKSCAN3 on HCC cells. In addition, we demonstrated that ZKSCAN3 expression was regulated by miR-124. In HCC tissues. MiR-124 has an inverse correlation with ZKSCAN3 expression.

Conclusion

We demonstrate for the first time that ZKSCAN3 is overexpressed in HCC tissues and promotes migration, invasion and EMT process through ITGB4-dependent FAK/AKT activation, which was regulated by miR-124, suggesting the potential therapeutic value for HCC.

A G-protein coupled receptor 39 agonist stimulates proliferation of keratinocytes via an ERK-dependent pathway

Keratinocyte proliferation serves as a crucial process in skin wound healing. The zinc-sensing G-protein coupled receptor 39 (GPR39), which is highly expressed in keratinocytes, has been shown to promote skin wound healing. The aim of this study was to investigate the effect of GPR39 activation on proliferation of keratinocytes and its underlying mechanism using immortalized human keratinocytes (HaCaT) as an in vitro model. GPR39 was functionally expressed in HaCaT cells. BrdU proliferation assays showed that treatment with GPR39 agonist TC-G 1008 (100 nM and 1 μM) increased cell proliferation. TC-G 1008 also enhanced ERK phosphorylation in time- and concentration-dependent manners. This effect was suppressed by co-treatment with wortmannin (PI3K inhibitor) and U0126 (MKK inhibitor). Of note, neither inhibition of Gα_q-phospholipase C (PLC)-[Ca²⁺]_i nor Gα_s-PKA pathway affected GPR39 stimulation-induced ERK phosphorylation. Similarly, barbadin, an inhibitor of G-protein-independent β-arrestin pathway, did not suppress ERK phosphorylation induced by GPR39 activation. Of particular importance, wortmannin, U0126, and FR180204 (ERK inhibitor) abrogated the effect of TC-G 1008-induced cell proliferation. Taken together, this study reveals novel insights into the role of GPR39 in regulating keratinocyte proliferation via a PI3K-MKK-ERK-dependent mechanism. GPR39 agonists may be used in enhancing keratinocyte proliferation, which may be beneficial for the cutaneous wound treatment.

Oncogenic pseudogene DUXAP10 knockdown suppresses proliferation and invasion and induces apoptosis of papillary thyroid carcinoma cells by inhibition of Akt/mTOR pathway

Pseudogenes, another novel group of non-coding segments without protein-coding capacity, are closely associated with tumourigenesis and cancer progression. Double homeoboxA pseudogene 10 (DUXAP10) is reported to be robustly expressed in thyroid carcinoma. However, the functional role and underlying mechanism of DUXAP10 in papillary thyroid carcinoma (PTC) progression remain undefined. DUXAP10 expression in PTC cells was detected by qRT-PCR. Cell proliferation and invasion were determined using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and Transwell invasion assay, respectively. Apoptosis was evaluated using flow cytometry. Protein expression of matrix metalloproteinase (MMP)-2, MMP-9, protein kinase B (Akt), phosphorylated Akt, mammalian target of rapamycin (mTOR), and phosphorylated mTOR was examined by western blot. Results showed that DUXAP10 was significantly overexpressed in PTC cells compared with normal thyroid follicular epithelium cells. DUXAP10 silencing suppressed cell proliferation and invasive ability, reduced the expression of MMP-2 and MMP-9, and increased apoptotic rate and caspase-3 activity in PTC cells. Additionally, the Akt/mTOR pathway was inhibited following DUXAP10 knockdown in PTC cells. Activation of the Akt/mTOR pathway by 740Y-P and MHY1485 attenuated DUXAP10 knockdown-induced proliferation reduction, invasion suppression and apoptosis in PTC cells. In conclusion, DUXAP10 knockdown suppressed proliferation and invasion and induced apoptosis in PTC cells at least partially by inhibition of the Akt/mTOR pathway.

Significance of lncRNA MIR31HG in predicting the prognosis for Chinese patients with cancer: a meta-analysis

It is important to clarify the significance of long noncoding RNA MIR31 host gene (lncRNA MIR31HG) in predicting the prognosis for malignant tumors through meta-analysis. Electronic databases were systemically searched, from inception until 2 January 2019, to identify related articles. Meanwhile, the hazard ratios (odds ratios) and 95% CIs were computed for exploring the association between the expression of lncRNA MIR31HG and the survival (pathological variables). Eleven studies with 1041 cases were enrolled into the current meta-analysis. Low expression of lncRNA MIR31HG showed correlation with the dismal overall survival, disease-free survival, high tumor stage and lymph node metastasis among patients with digestive system cancers. Low expression of lncRNA MIR31HG may serve as a potential novel factor to indicate the dismal prognosis and metastasis in patients with digestive system cancers.

microRNA-1914, which is regulated by lncRNA DUXAP10, inhibits cell proliferation by targeting the GPR39-mediated PI3K/AKT/mTOR pathway in HCC

Increasing studies have confirmed that abnormally expressed microRNAs (miRNAs) take part in the carcinogenesis as well as the aggravation of hepatocellular carcinoma (HCC). However, little information is currently available about miR-1914 in HCC. Here, we first confirmed that miR-1914 inhibition in HCC cell lines and tumour specimens correlates with tumour size and histological grade. In a series of functional experiments, miR-1914 inhibited tumour proliferation and colony formation, resulting in cell cycle arrest and increased apoptosis. Moreover, miR-1914 mediated its functional effects by directly targeting GPR39 in HCC cells, leading to PI3K/AKT/mTOR repression. Restoring GPR39 expression incompletely counteracted the physiological roles of miR-1914 in HCC cells. In addition, down-regulation of AKT phosphorylation inhibited the effects of miR-1914 in HCC. Furthermore, the overexpression of lncRNA DUXAP10 negatively correlated with the expression of miR-1914 in HCC; thus, lncRNA DUXAP10 regulated miR-1914 expression and modulated the GPR39/PI3K/AKT-mediated cellular behaviours. In summary, the present study demonstrated for the first time that lncRNA DUXAP10-regulated miR-1914 plays a functional role in inhibiting HCC progression by targeting GPR39-mediated PI3K/AKT/mTOR pathway, and this miRNA represents a novel therapeutic target for patients with HCC.