Idebenone Exerts anti-Triple Negative Breast Cancer Effects via Dual Signaling Pathways of GADD45 and AMPK.

Idebenone, a mitochondrial regulator, has exhibited anti-cancer activity in neurogenic and prostate tumor cells; however, its efficacy and specific targets in the treatment of triple-negative breast cancer (TNBC) remain unclear. This study aims to evaluate the potential of Idebenone as a therapeutic agent for TNBC. TNBC cell lines and Xenograft mouse models were used to assess the effect of Idebenone on TNBC both in vitro and in vivo. To investigate the underlying mechanism of Idebenone's effect on TNBC, cell viability assay, transwell invasion assay, cell cycle analysis, apoptosis assay, mitochondrial membrane potential assay, immunofluorescence staining, and transcriptome sequencing were utilized. The results showed that Idebenone impeded the proliferation, colony formation, migration, and invasion of TNBC cells, suppressed apoptosis, and halted the cell cycle in the G2/M phase. The inhibitory effect of Idebenone on TNBC was associated with the GADD45/CyclinB/CDK1 signaling pathway. By disrupting the mitochondrial membrane potential (MMP) and promoting mitophagy, Idebenone promoted cell autophagy through the AMPK/mTOR pathway, thus further suppressing the proliferation of TNBC cells. Furthermore, we found that Idebenone inhibited the development of TNBC in vivo. In conclusion, Idebenone may be a promising therapeutic option for TNBC as it is capable of inducing autophagy and apoptosis.

VEGF-B prevents excessive angiogenesis by inhibiting FGF2/FGFR1 pathway.

Although VEGF-B was discovered as a VEGF-A homolog a long time ago, the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups. Notwithstanding, drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases. It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms. Using comprehensive in vitro and in vivo methods and models, we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed. Mechanistically, we unveil that VEGF-B binds to FGFR1, induces FGFR1/VEGFR1 complex formation, and suppresses FGF2-induced Erk activation, and inhibits FGF2-driven angiogenesis and tumor growth. Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway. Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels, caution is warranted when modulating VEGF-B activity to treat neovascular diseases.

CircRNA hsa_circRNA_104348 promotes hepatocellular carcinoma progression through modulating miR-187-3p/RTKN2 axis and activating Wnt/ß-catenin pathway.

Circular RNAs (circRNAs) have confirmed to participate in diverse biological functions in cancer. However, the expression patterns of circRNAs on hepatocellular carcinoma (HCC) remains unclear. In the present study, we clarified that hsa_circRNA_104348 was dramatically upregulated in HCC tissues and cells. Patients with HCC displaying high hsa_circRNA_104348 level possessed poor prognosis. Has_circ_104348 facilitated proliferation, migration, and invasion, meanwhile suppressed apoptosis of HCC cell. Furthermore, hsa_circRNA_104348 directly targeted miR-187-3p, could regulate miR-187-3p to affect proliferation, migration, invasion, and apoptosis of HCC cells, and may have effect on Wnt/ß-catenin signaling pathway. Moreover, RTKN2 could be a direct target of miR-187-3p. In addition, knockdown of hsa_circRNA_104348 attenuated HCC tumorigenesis and lung metastasis in vivo. Taken together, these findings indicated that circular RNA hsa_circRNA_104348 might function as a competing endogenous RNA (ceRNA) to promotes HCC progression by targeting miR-187-3p/RTKN2 axis and activating Wnt/ß-catenin pathway.

Circular RNA Gprc5a Promotes HCC Progression by Activating YAP1/TEAD1 Signalling Pathway by Sponging miR-1283.

BACKGROUND: Circular RNA (circRNA) plays a critical role in tumorigenesis and tumor progression. Many studies indicate that circRNA Gprc5a is significantly upregulated and functions as an oncogene in a variety of cancers. However, the molecular mechanism of circGprc5a in liver cancer remains unclear. METHODS: qRT-PCR was used to measure the expression levels of circGprc5a, miR-1283, YAP1 and TEAD1 mRNA in hepatocellular carcinoma (HCC) tissues or cells. YAP1 and TEAD1 protein levels were detected by Western blot. CCK-8 assay, cell colony formation, BrdU incorporation and Annexin V-FITC/PI assays were performed to analyze the effects of circGprc5a and miR-1283 on cell proliferation and apoptosis. The relationship between circGprc5a, miR-1283, YAP1 and TEAD1 was analyzed using bioinformatic analysis and luciferase. The tumor changes in mice were detected by in vivo experiments. RESULTS: CircGprc5a was highly expressed in liver cancer, and closely related poor survival of patients with liver cancer. Knockout of circGprc5a inhibited proliferation of HCC and induced apoptosis. CircGprc5a activated the YAP1/TEAD1 signaling pathway by acting as a sponge for miR-1283. Furthermore, overexpression of miR-1283 abolished the promotion of circGprc5a on HCC cells. Therefore, miR-1283 expression correlated negatively with circGprc5a expression yet positively with the expression of YAP1/TEAD1 in liver cancer. CONCLUSION: CircGprc5a promoted the development of HCC by inhibiting the expression of miR-1283 and activating the YAP1/TEAD1 signaling pathway.

Correction to: LncMAPK6 drives MAPK6 expression and liver TIC self-renewal.

In the original publication of this article [1], the author found an error in Fig. 2f. lncGPR107 should be changed to lncMAPK6, and the corrected Fig. 2 is shown below.

Elevated levels of hsa_circ_006100 in gastric cancer promote cell growth and metastasis via miR-195/GPRC5A signalling.

OBJECTIVES: Circular RNAs (circRNAs) are non-coding RNAs, some of which are thought to be involved in gastric cancer development. Here, we examined the functions of circRNA hsa_circ_006100 in gastric cancer cells and an animal model of gastric cancer. MATERIALS AND METHODS: The expression of hsa_circ_006100, miR-195 and various functional genes was determined by quantitative RT-PCR. Cell viability, clone formation, apoptosis and cell migration/invasion abilities were analysed by the CCK-8 assay, crystal violet staining, Hoechst staining and Transwell assay, respectively. A tumour model was established by subcutaneously injecting tumour cells into nude mice. Levels of protein expression were analysed by Western blotting and immunohistochemistry. RESULTS: A bioinformatics analysis showed that miR-195 was negatively co-expressed with hsa_circ_006100. Patients with a high hsa_circ_006100 level or low miR-195 level had tumours with a high TNM stage, poor cellular differentiation and lymph node metastasis. miR-195 was targeted and inhibited by hsa_circ_006100. Overexpression of hsa_circ_006100 enhanced cellular viability and proliferation, while miR-195 suppressed hsa_circ_006100-enhanced cell growth and induced apoptosis in MGC-803 and AGS cells. Forced hsa_circ_006100 expression promoted the migration and invasion of MGC-803 and AGS cells, while those activities were inhibited by miR-195. Mechanistically, GPRC5A was predicted as a target of miR-195 and was upregulated in gastric cancer. A miR-195 inhibitor restored cell viability, proliferation, migration and invasion, and repressed apoptosis via GPRC5A. In vivo studies showed that knockdown of hsa_circ_006100 delayed tumour growth, reduced PCNA expression and upregulated miR-195 and BCL-2 expression which was restored by miR-195 inhibition due to GPRC5A/EGFR signalling, and changed the EMT phenotype in vivo. CONCLUSIONS: Hsa_circ_006100 functions as an oncogene in gastric cancer and exerts its effects via miR-195/GPRC5A signalling.

The lncRNA TDRG1 promotes cell proliferation, migration and invasion by targeting miR-326 to regulate MAPK1 expression in cervical cancer.

BACKGROUND: Recently, lncRNA-Testis developmental related gene 1 (TDRG1) was proved to be a key modulator in reproductive organ-related cancers. The biological role of TDRG1 in cervical cancer (CC) progression remains largely unknown. METHOD: Real-time PCR (qRT-PCR) examined the expression level of TDRG1, microRNA (miR)-326 and MAPK1 mRNA. OS tissues and corresponding relative normal tissues, as well as CC cell lines and normal cell line Ect1/E6E7 were collected to determine the expression of TDRG1 in CC. MTT, colony formation, wound-healing, transwell and flow cytometer assay detected the influence of TDRG1 and miR-326 on CC cells growth, metastasis and apoptosis. Western blot examined proteins level. Bioinformatics, RNA pull-down assay, RNA immunoprecipitation and dual-luciferase reporter assays detected the molecular mechanism of TDRG1 in CC. Xenograft tumour model was established to determine the role of TDRG1 in vivo. RESULTS: The expression of TDRG1 was significantly increased in CC tissues and cell lines compared with normal tissue and normal cell line respectively and its expression was associated with clinicopathological characteristics of CC patients. Knockdown of TDRG1 inhibited the cell proliferation, migration and invasion in Hela and SIHA cells. Moreover, TDRG1 directly interacted with miR-326, and the inhibition effect on cell growth and metastasis induced by TDRG1 siRNA can be abrogated by miR-326 silencing by its inhibitor in Hela and SIHA cells. Further, MAPK1 was proved to be a direct target of miR-326, and its expression was negatively regulated by miR-326 while positively modulated by TDRG1. CONCLUSION: TDRG1 acts as a competing endogenous lncRNA (ceRNA) to modulate MAPK1 by sponging miR-326 in CC, shedding new light on TDRG1-directed diagnostics and therapeutics in CC.

Prognostic value of plasma fibrinogen in hepatocellular carcinoma: a meta-analysis.

BACKGROUND: Elevated plasma fibrinogen levels have been associated with tumor progression in several malignancies. Our study aims to characterize the clinical significance of elevated plasma fibrinogen levels in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Relevant published articles were systematically searched in electronic databases including PubMed, Embase, and Web of Science. The pooled differences in plasma fibrinogen levels among HCC, cirrhotic, and control groups were expressed as weighted mean differences (WMDs) and their corresponding 95% CIs. The associations between elevated fibrinogen and overall survival (OS) and disease-free survival (DFS)/recurrence-free survival (RFS) were expressed as HRs and their 95% CIs, whereas the associations between elevated fibrinogen and various types of clinical characteristic of patients with HCC were expressed as ORs and their corresponding 95% CIs. RESULTS: Results showed that the plasma fibrinogen levels in patients with HCC were not significantly different than that in healthy controls (WMD = 0.50, 95% CI = [-0.82, 1.82], P = 0.457) or patients with cirrhosis (WMD = -0.62, 95% CI = [-1.56, 0.33], P = 0.200). However, our results showed that compared to those with normal levels, patients with HCC and elevated plasma fibrinogen levels showed poorer OS (HR = 2.08, 95% CI = [1.67, 2.59], P < 0.0001) and DFS/RFS (HR = 1.90, 95% CI = [1.52, 2.37], P < 0.0001). Results of trial sequential analysis of the OS indicated that currently available studies were sufficient to validate the negative prognostic value of elevated plasma fibrinogen in patients with HCC. Clinicopathological analyses showed that high plasma fibrinogen levels were associated with tumor progression as indicated by advanced tumor stage, larger tumor size, increased tumor number, and the presence of vascular invasion. CONCLUSION: Elevated plasma fibrinogen levels are associated with poor prognosis and advanced tumor progression. Plasma fibrinogen may serve as a negative prognostic biomarker in patients with HCC.

Long non-coding RNA TPT1-AS1 promotes cell growth and metastasis in cervical cancer via acting AS a sponge for miR-324-5p.

BACKGROUND: Increasing studies confirmed that abnormal lncRNAs expression play a critical role in cervical cancer (CC) development and progression. LncRNA TPT1-AS1, a novel lncRNA, its role and underlying mechanisms involved in CC remain largely unknown. METHODS: Colony formation, EdU and Transwell assays were used to determine colony formation, proliferation, migration and invasion in vitro. The subcutaneous tumor model and tail vein injection lung metastasis model were performed to check tumor growth and metastasis in vivo. Luciferase activity and RIP experiment were carried out to determine the interaction between miR-324-5p and TPT1-AS1. RESULTS: We demonstrated for the first time that TPT1-AS1 expression was up-regulated in CC tissues and cell lines. High TPT1-AS1 was significantly correlated with adverse prognostic characteristics and poor survival. TPT1-AS1 overexpression and knockdown experiments revealed that TPT1-AS1 promoted cell colony formation, proliferation, migration, invasion and EMT progression of CC cells in vitro and in vivo. The underlying mechanism indicated that TPT1-AS1 functioned as an endogenous sponge for miR-324-5p in CC cells. Gain- and loss- experiment confirmed that miR-324-5p inhibited cell colony formation, proliferation, migration, invasion and EMT progression of CC cells, and mediated the biological effects of TPT1-AS1. Further investigations confirmed that SP1 was a direct target of miR-324-5p and mediated the effects of TPT1-AS1 and miR-324-5p in CC. CONCLUSIONS: We demonstrated for the first time that TPT1-AS1 as an oncogenic lncRNA in CC progression and as a potential target for CC cure.

LncGPR107 drives the self-renewal of liver tumor initiating cells and liver tumorigenesis through GPR107-dependent manner.

BACKGROUND: With self-renewal and differentiation properties, liver tumor initiating cells (TICs) are the reasons for tumor initiation, metastasis and drug resistance. G protein coupled receptors (GPCR) are critical modulators in many physiological and pathological processes. While, their roles in liver TICs are unknown. METHODS: An unbiased screening was performed using online-available data dataset. Liver TICs were sorted by FACS with surface marker CD133, or enriched by oncosphere formation. TIC self-renewal was examined by oncosphere formation and tumor initiation assay. Loss of function and gain of function assays were performed to examine the role of lncRNA. RNA pulldown, RNA immunoprecipitation, ChIP, western blot and double FISH were used explore the molecular mechanism of lncRNA. RESULTS: We performed an unbiased screening for GPCR expression in liver cancers, and found GPR107 was the most highly expressed GPCR in liver cancer and liver TICs. GPR107 was essential for the self-renewal of liver TICs. The expression of GPR107 was regulated by a long noncoding RNA lncGPR107. LncGPR107 was also highly expressed in liver cancers and liver TICs. LncGPR107 drove the self-renewal of liver TICs through GPR107. Moreover, lncGPR107 recruited SRCAP complex to GPR107 promoter to drive its transcriptional activation. LncGPR107 depletion inhibited the binding of SRCAP complex and GPR107 promoter and subsequent GPR107 expression. Moreover, LncGPR107-SRCAP-GPR107 can be targeted for liver TIC elimination. CONCLUSION: GPR107 was the most highly expressed GPCR in liver cancer and liver TICs. LncGPR107 participated in the transcriptional regulation of GPR107 in cis, through recruiting SRCAP remodeling complex to GPR107 promoter. This work revealed the important role of GPCR signaling in liver TIC self-renewal and added a new layer for liver TIC and GPCR regulation.

LncMAPK6 drives MAPK6 expression and liver TIC self-renewal.

BACKGROUND: Liver tumor initiating cells (TICs) have self-renewal and differentiate capacities, and largely contribute to tumor initiation, metastasis and drug resistance. MAPK signaling is a critical pathway in many biological processes, while its role in liver TICs hasn't been explored. METHODS: Online-available dataset was used for unbiased screening. Liver TICs were examined CD133 FACS or oncosphere formation. TIC self-renewal was detected by oncosphere formation and tumor initiation assay. LncRNA function was detected by loss of function or gain of function assays. The molecular mechanism of lncRNA was explored by RNA pulldown, RNA immunoprecipitation, ChIP, western blot and double FISH. RESULTS: Here, we examined the expression profiles of MAPK components (MAPKs, MAP2Ks, MAP3Ks, MAP4Ks), and found MAPK6 is most highly expressed in liver cancer samples. Moreover, a divergent lncRNA (long noncoding RNA) of MAPK6, termed lncMAPK6 here, is also overexpressed along with liver tumorigenesis. LncMAPK6 promotes liver tumor propagation and TIC self-renewal through MAPK6. LncMAPK6 interacts with and recruits RNA polymerase II to MAPK6 promoter, and finally activates the transcription of MAPK6. Through MAPK6 transcriptional regulation, lncMAPK6 drives MARK signaling activation. LncMAPK6-MAPK6 pathway can be used for liver TIC targeting. Altogether, lncMAPK6 promotes MARK signaling and the self-renewal of liver TICs through MAPK6 expression. CONCLUSION: MAPK6 was the most highly expressed MAPK component in liver cancer and liver TICs and lncMAPK6 participated in the transcriptional regulation of MAPK6in cis. This work revealed the importance role of MAPK signaling in liver TIC self-renewal and added a new layer for liver TIC and MAPK6 expression regulation.

lncAKHE enhances cell growth and migration in hepatocellular carcinoma via activation of NOTCH2 signaling.

Hepatocellular carcinoma is the sixth most common cancer and gives rise to numerous deaths around the world every year. However, the molecular mechanism that controls hepatocarcinogenesis remains largely unknown. Here we found out an uncharacterized long noncoding RNA named lncAKHE. We found that lncAKHE was highly expressed in hepatocellular carcinoma tissues. lncAKHE depletion remarkably impaired the abilities of cell proliferation, migration, and invasion in hepatocellular carcinoma while promgoogoting cell apoptosis. Moreover, higher expression level of lncAKHE in hepatocellular carcinoma tissues was associated with more clinical severity and lower survival rates. Mechanistically, lncAKHE cooperated with YEATS4 to enhance the activation of NOTCH2 signaling which is usually abnormally upregulated in hepatocellular carcinoma. In conclusions, our study showed that lncAKHE may promote tumor progression in HCC and serve as a novel target for HCC treatment.

CDK3, target of miR-4469, suppresses breast cancer metastasis via inhibiting Wnt/ß-catenin pathway.

Cyclin-dependent kinase 3 (CDK3), a member of CDK family, is involved in G0/G1 and G1/S cell cycle transitions. Although several researchers discovered that CDK3 related to cell growth in some kinds of cancer, the functions of CDK3 during tumor development remains unclear. Here, we first found that the expression of CDK3 was higher in primary tumors of non-metastatic breast cancer compared with those in metastatic breast cancer. Overexpression of CDK3 suppressed cell migration and invasion of breast cancer cells, and decreased the metastasis in nude mice. We further identified miR-4469 was a negative regulator of CDK3 by directly targeting its 3'-untranslated region (UTR). The increase of motility induced by miR-4469 could be abolished by CDK3 overexpression. Moreover, RNA-seq analysis revealed that Wnt pathway may be inhibited by CDK3 expression, which was subsequently confirmed by western blot. Moreover, Wnt3a treatment abolished the inhibitory role of CDK3 in cell motility, suggesting that Wnt signaling is the potential downstream of CDK3. In conclusion, these results support that CDK3 which is targeted by miR-4469 suppresses breast cancer metastasis by inhibiting Wnt/ß-catenin pathway.

Recent progress in circular RNAs in human cancers.

Circular RNAs (circRNAs) are a large class of endogenous RNAs, formed by exon skipping or back-splicing events as covalently closed loops, which are expressed abundantly in mammalian cells. Although their biological functions remain largely unknown, recent studies show that circRNAs have three main functions in mammalian cells. First, circRNAs can regulate transcription and RNA splicing. Second, circRNAs function as microRNA (miRNA) sponges. Third, they can be translated into protein driven by N6-methyladenosine modification. Taking advantage of RNA sequencing (RNA-seq) technology, the expressions of circRNAs were found to be dysregulated in all types of cancer cell lines, tumor tissues, and even plasma samples from patients, which correlated with certain clinical characteristics, suggesting the potential roles of circRNAs in tumor progression. Considering their conserved sequences and stable structures, circRNAs were deemed to be promising biomarkers for the early diagnosis and prognosis prediction of cancer. In this review, we describe briefly the formation and properties of circRNAs, and focus mainly on recent progress in research into their function, regulation, and clinical relevance in different cancers.

Increased gene expression noise in human cancers is correlated with low p53 and immune activities as well as late stage cancer.

Gene expression in metazoans is delicately organized. As genetic information transmits from DNA to RNA and protein, expression noise is inevitably generated. Recent studies begin to unveil the mechanisms of gene expression noise control, but the changes of gene expression precision in pathologic conditions like cancers are unknown. Here we analyzed the transcriptomic data of human breast, liver, lung and colon cancers, and found that the expression noise of more than 74.9% genes was increased in cancer tissues as compared to adjacent normal tissues. This suggested that gene expression precision controlling collapsed during cancer development. A set of 269 genes with noise increased more than 2-fold were identified across different cancer types. These genes were involved in cell adhesion, catalytic and metabolic functions, implying the vulnerability of deregulation of these processes in cancers. We also observed a tendency of increased expression noise in patients with low p53 and immune activity in breast, liver and lung caners but not in colon cancers, which indicated the contributions of p53 signaling and host immune surveillance to gene expression noise in cancers. Moreover, more than 53.7% genes had increased noise in patients with late stage than early stage cancers, suggesting that gene expression precision was associated with cancer outcome. Together, these results provided genomic scale explorations of gene expression noise control in human cancers.

W346 inhibits cell growth, invasion, induces cycle arrest and potentiates apoptosis in human gastric cancer cells in vitro through the NF-κB signaling pathway.

The therapeutic agent selectively killing cancer cells is urgently needed for gastric cancer treatment. Curcumin has been investigated for its effect on the cancer treatment because of its significant therapeutic potential and safety profile. A synthetic unsymmetry mono-carbonyl compound termed W346 was developed from curcumin. In this study, we investigated the potential antineoplastic effect and mechanism of W346 against human gastric cancer cells. W346 suppressed the proliferation and invasion, blocked cell cycle arrest at G2/M phase, and increased apoptosis in gastric cancer cells, and it presented obviously improved anticancer activity than curcumin. Moreover, W346 effectively inhibited tumor necrosis factor (TNF-α)-induced NF-κB activation by suppressing IKK phosphorylation, inhibiting IκB-α degradation, and restraining the accumulation of NF-κB subunit p65 nuclear translocation. W346 also affected NF-κB-regulated downstream products involved in cycle arrest and apoptosis. In a word, W346 exhibited significantly improved anti-gastric cancer activity over curcumin by targeting NF-κB signaling pathway, and it is likely to be a promising starting point for the development of curcumin-based therapeutic agent.

p53 Configures the G2/M Arrest Response of Nucleostemin-Deficient Cells.

Nucleostemin (NS) protects the genome from replication-induced DNA damage and plays an indispensable role in maintaining the continuous proliferation of both p53-wildtype and mutant cells. Yet, some outcomes of NS-deficient cells appear to be shaped by their p53 status, which stimulates conflicting claims on the role of p53 in executing the NS function. This disparity was conveniently attributed to the usual suspect of cell-type variations. To provide a definitive resolution, we investigated the interplay between NS and p53 in two pairs of isogenic cells, i.e. genetically modified mouse embryonic fibroblast (MEF) cells and HCT116 human colon cancer cells. In MEF cells, p53 deletion further compromises rather than rescues the proliferative potential of NS-depleted cells without changing their G2/M arrest fate before prophase entry. The detrimental effect of p53 loss in NS-depleted MEF cells correlates with a dramatic increase of polyploid giant cells (PGCs) (up to 24%), which indicates aberrant mitosis. To determine how p53 shapes the response of cells to NS depletion at the molecular level, we showed that p53 turns on the expression of reprimo and MDM2 in NS-deficient MEF cells. In the absence of p53, NS-deficient MEF cells exhibit increased levels of phosphorylated cdc2 (Y15) protein and cyclin B1. In cancer (HCT116) cells, NS loss leads to G2/M arrest under both p53wt and p53ko conditions and increases phosphorylated cdc2 more in p53ko than in p53wt cells, as it does in MEF cells. Unlike its effect in MEF cells, NS depletion decreases tumor growth and increases the expression of reprimo and cyclin B1 in a p53-independent manner in HCT116 cells. Our data indicate that the p53 status of NS-deficient cells orchestrates how they respond to G2/M arrest in a normal vs. cancer cell distinct fashion.