ANT2 shRNA downregulates miR-19a and miR-96 through the PI3K/Akt pathway and suppresses tumor growth in hepatocellular carcinoma cells

Exploring the multifaceted role of adenosine nucleotide translocase 2 in cellular and disease processes: A comprehensive review

Adenosine nucleotide translocases (ANTs) are a family of proteins abundant in the inner mitochondrial membrane, primarily responsible for shuttling ADP and ATP across the mitochondrial membrane. Additionally, ANTs are key players in balancing mitochondrial energy metabolism and regulating cell death. ANT2 isoform, highly expressed in undifferentiated and proliferating cells, is implicated in the development and drug resistance of various tumors. We conduct a detailed analysis of the potential mechanisms by which ANT2 may influence tumorigenesis and drug resistance. Notably, the significance of ANT2 extends beyond oncology, with roles in non-tumor cell processes including blood cell development, gastrointestinal motility, airway hydration, nonalcoholic fatty liver disease, obesity, chronic kidney disease, and myocardial development, making it a promising therapeutic target for multiple pathologies. To better understand the molecular mechanisms of ANT2, this review summarizes the structural properties, expression patterns, and basic functions of the ANT2 protein. In particular, we review and analyze the controversy surrounding ANT2, focusing on its role in transporting ADP/ATP across the inner mitochondrial membrane, its involvement in the composition of the mitochondrial permeability transition pore, and its participation in apoptosis.

Evaluation of the effect of GSK-3β on liver cancer based on the PI3K/AKT pathway

The PI3K/AKT/GSK-3β signaling pathway plays a pivotal role in numerous physiological and pathological processes, including cell proliferation, apoptosis, differentiation, and metabolic regulation. Aberrant activation of the PI3K/AKT pathway is intricately linked to development of tumor. GSK-3β, belonging to the serine/threonine protein kinase family, is crucial in the pathogenesis of liver cancer. As a key rate-limiting enzyme in the glucose metabolism pathway, GSK-3β significantly impacts the growth, proliferation, metastasis, and apoptosis of liver cancer cells. It is also implicated in chemotherapy resistance. Elevated expression of GSK-3β diminishes the sensitivity of liver cancer cells to chemotherapeutic agents, thereby playing a substantial role in the development of drug resistance. Consequently, targeting of GSK-3β, particularly within the PI3K/AKT signaling pathway, is regarded as a promising therapeutic strategy for liver cancer. The precise identification and subsequent modulation of this pathway represent a substantial potential for innovative clinical interventions in the management of liver cancer.

Disrupting CCDC137-mediated LZTS2 and β-TrCP interaction in the nucleus inhibits hepatocellular carcinoma development via β-catenin and AKT

Hepatocellular carcinoma (HCC) is a highly heterogeneous solid tumor, with its biological characteristics intricately linked to the activation of oncogenes. This research specifically explored CCDC137, a molecule within the CCDC family exhibiting the closest association with HCC. Our investigation aimed to unravel the role, underlying mechanisms, and potential therapeutic implications of CCDC137 in the context of HCC. We observed a close correlation between elevated CCDC137 expression and poor prognosis in HCC patients, along with a promotive effect on HCC progression in vitro and in vivo. Mechanistically, we identified LZTS2, a negative regulator of β-catenin, as the binding protein of CCDC137. CCDC137 facilitated K48-linked poly-ubiquitination of LZTS2 at lysine 467 via recruiting E3 ubiquitin ligase β-TrCP in the nucleus, triggering AKT phosphorylation and activation of β-catenin pathway. Moreover, the 1-75 domain of CCDC137 was responsible for the formation of the CCDC137-LZTS2-β-TrCP complex. Subsequently, designed peptides targeting the 1-75 domain of CCDC137 to disrupt CCDC137-LZTS2 interaction demonstrated efficacy in inhibiting HCC progression. This promising outcome was further supported by HCC organoids and patient-derived xenograft (PDX) models, underscoring the potential clinical utility of the peptides. This study elucidated the mechanism of the CCDC137-LZTS2-β-TrCP protein complex in HCC and offered clinically significant therapeutic strategies targeting this complex.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Decoding the interaction between miR-19a and CBX7 focusing on the implications for tumor suppression in cancer therapy

Cancer is a complex and multifaceted disease characterized by uncontrolled cell growth, genetic alterations, and disruption of normal cellular processes, leading to the formation of malignant tumors with potentially devastating consequences for patients. Molecular research is important in the diagnosis and treatment, one of the molecular mechanisms involved in various cancers is the fluctuation of gene expression. Non-coding RNAs, especially microRNAs, are involved in different stages of cancer. MicroRNAs are small RNA molecules that are naturally produced within cells and bind to the 3'-UTR of target mRNA, repressing gene expression by regulating translation. Overexpression of miR-19a has been reported in human malignancies. Upregulation of miR-19a as a member of the miR-17-92 cluster is key to tumor formation, cell proliferation, survival, invasion, metastasis, and drug resistance. Furthermore. bioinformatics and in vitro data reveal that the miR-19a-3p isoform binds to the 3'UTR of CBX7 and was identified as the miR-19a-3p target gene. CBX7 is known as a tumor suppressor. This review initially describes the regulation of mir-19a in multiple cancers. Accordingly, the roles of miR-19 in affecting its target gene expression CBX7 in carcinoma also be discussed.

UBE2S promotes malignant properties via VHL/HIF-1α and VHL/JAK2/STAT3 signaling pathways and decreases sensitivity to sorafenib in hepatocellular carcinoma

BACKGROUND

Ubiquitin-conjugating enzyme E2S (UBE2S), an E2 enzyme, is associated with the development of various tumors and exerts oncogenic activities. UBE2S is overexpressed in tumors, including hepatocellular carcinoma (HCC). However, the key molecular mechanisms of UBE2S in HCC still need additional research. The aim of this study was to explore the role of UBE2S in HCC.

METHODS

The expression levels of UBE2S in HCC tissues and cells were detected by western blot analysis, quantitative real-time polymerase chain reaction analysis (qRT-PCR), and immunohistochemistry (IHC). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, wound healing assay, colony formation assay transwell assay, and animal models were used to detect the proliferation and migration ability of HCC cells. Western blot analysis, qRT-PCR, immunofluorescence, small-interfering RNA (siRNA), and plasmid transfection and coimmunoprecipitation (Co-IP) assays were performed to detect the interaction among UBE2S, von Hippel-Lindau (VHL), hypoxia-inducible factor 1-alpha (HIF-1α), Janus kinase-2 (JAK2), and signal transducer and activator of transcription 3 (STAT3).

RESULTS

In this study, we found that high UBE2S expression was associated with poor prognosis in HCC patients. In addition, UBE2S expression was upregulated in HCC tissues and cell lines. Knockdown of UBE2S inhibited the proliferation and migration of HCC cells in vitro and in vivo by directly interacting with VHL to downregulate the HIF-1α and JAK2/STAT3 signaling pathways. Accordingly, overexpression of UBE2S significantly enhanced the proliferation and migration of HCC cells in vitro via VHL to upregulate HIF-1α and JAK2/STAT3 signaling pathways. Furthermore, we found that downregulation of UBE2S expression enhanced the sensitivity of HCC cells to sorafenib in vivo and in vitro.

CONCLUSION

UBE2S enhances malignant properties via the VHL/HIF-1α and VHL/JAK2/STAT3 signaling pathways and reduces sensitivity to sorafenib in HCC. The findings of this study may open a new approach for HCC diagnosis and provide a potential option for the treatment of HCC.

Targeting the PI3K/AKT/mTOR and RAF/MEK/ERK pathways for cancer therapy

The PI3K/AKT/mTOR and RAF/MEK/ERK pathways are commonly activated by mutations and chromosomal translocation in vital targets. The PI3K/AKT/mTOR signaling pathway is dysregulated in nearly all kinds of neoplasms, with the component in this pathway alternations. RAF/MEK/ERK signaling cascades are used to conduct signaling from the cell surface to the nucleus to mediate gene expression, cell cycle processes and apoptosis. RAS, B-Raf, PI3K, and PTEN are frequent upstream alternative sites. These mutations resulted in activated cell growth and downregulated cell apoptosis. The two pathways interact with each other to participate in tumorigenesis. PTEN alterations suppress RAF/MEK/ERK pathway activity via AKT phosphorylation and RAS inhibition. Several inhibitors targeting major components of these two pathways have been supported by the FDA. Dozens of agents in these two pathways have attracted great attention and have been assessed in clinical trials. The combination of small molecular inhibitors with traditional regimens has also been explored. Furthermore, dual inhibitors provide new insight into antitumor activity. This review will further comprehensively describe the genetic alterations in normal patients and tumor patients and discuss the role of targeted inhibitors in malignant neoplasm therapy. We hope this review will promote a comprehensive understanding of the role of the PI3K/AKT/mTOR and RAF/MEK/ERK signaling pathways in facilitating tumors and will help direct drug selection for tumor therapy.

An integrated bioinformatic investigation of mitochondrial solute carrier family 25 (SLC25) in colon cancer followed by preliminary validation of member 5 (SLC25A5) in tumorigenesis

Solute carrier family 25 (SLC25) encodes transport proteins at the inner mitochondrial membrane and functions as carriers for metabolites. Although SLC25 genetic variants correlate with human metabolic diseases, their roles in colon cancer remain unknown. Cases of colon cancer were retrieved from The Cancer Genome Atlas, and the transcriptionally differentially expressed members (DEMs) of SLC25 were identified. DNA level alterations, clinicopathological characteristics, and clinical survival were also investigated. A risk score model based on the DEMs was constructed to further evaluate their prognostic values in a clinical setting. The results were preliminarily validated using bioinformatic analysis of datasets from the Gene Expression Omnibus, immunohistochemical evaluations in clinical specimens, and functional experiments in colon cancer-derived cell lines. Thirty-seven DEMs were identified among 53 members of SLC25. Eight of 37 DEMs were introduced into a risk score model using integrated LASSO regression and multivariate Cox regression. Validated by GSE395282 and GSE175356, DEMs with high-risk scores were associated with the phenotypes of increasing tumor immune infiltration and decreasing glycolysis and apoptosis contents. SLC25A5 was downregulated in cancer, and its upregulation was related to better overall survival in patients from public datasets and in clinical cases. High SLC25A5 expression was an independent prognostic factor for 79 patients after surgical treatment. A negative correlation between CD8 and SLC25A5 was determined in specimens from 106 patients with advanced colon cancer. SLC25A5 attenuated cell proliferation, upregulated the expression of programmed cell death-related signatures, and exerted its biological function by inhibiting the MAPK signaling pathway. Our study reveals that mitochondrial SLC25 has prognostic value in patients with colon cancer. The bioinformatic analyses by following verification in situ and in vitro provide direction for further functional and mechanistic studies on the identified member of SLC25.

Crosstalk between miRNA and PI3K/AKT/mTOR signaling pathway in cancer

Phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important proliferative signaling pathways with critical undeniable function in various aspects of cancer initiation/progression, including proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. On the other hand, numerous genetic alterations in the key genes involved in the PI3K/AKT/mTOR signaling pathway have been identified in multiple solid and hematological tumors. In addition, accumulating recent evidences have demonstrated a reciprocal interaction between this signaling pathway and microRNAs, a large group of small non-coding RNAs. Therefore, in this review, it was attempted to discuss about the interaction between key components of PI3K/AKT/mTOR signaling pathway with various miRNAs and their importance in cancer biology.

Suppression of ANT2 by miR-137 Inhibits Prostate Tumorigenesis

Prostate cancer (PCa) is a serious disease that affects men’s health. To date, no effective and long-lasting treatment option for this condition is available in clinical practice. ANT2 is highly expressed in a variety of hormone-related cancers, but its relationship and regulatory mechanism with PCa are unclear. In this study, we found that ANT2 expression was significantly upregulated in PCa tissues relative to control samples. Genetic knockdown of ANT2 effectively inhibited, while overexpression promoted, proliferation, migration, and invasion of PCa cells. In addition, miR-137 expression was reduced in prostate cancer tissues relative to control tissues. We identified a regulatory site for miR-137 in the 3′-UTR of ANT2 mRNA; luciferase reporter assays indicated that ANT2 is a direct target gene for miR-137. Transfecting cells with miR-137 mimics and/or an ANT2-encoding plasmid revealed that ANT2 promotes proliferation, migration, and invasion of PCa, whereas co-expression of miR-137 mimics inhibited these behaviors. These observations suggest that miR-137 mimics inhibit development of PCa by antagonizing expression of ANT2. Furthermore, tumorigenic assays in nude mice showed that miR-137 inhibitors abolished the inhibitory effect of ANT2 knockdown on PCa tumor growth. Collectively, our findings suggest that ANT2, a target gene of miR-137, is intimately involved in development of PCa, providing new evidence for the mechanism underlying pathogenesis of PCa as well as new options for targeted therapy.

Role of miRNA-19a in Cancer Diagnosis and Poor Prognosis

Cancer is a multifactorial disease that affects millions of people every year and is one of the most common causes of death in the world. The high mortality rate is very often linked to late diagnosis; in fact, nowadays there are a lack of efficient and specific markers for the early diagnosis and prognosis of cancer. In recent years, the discovery of new diagnostic markers, including microRNAs (miRNAs), has been an important turning point for cancer research. miRNAs are small, endogenous, non-coding RNAs that regulate gene expression. Compelling evidence has showed that many miRNAs are aberrantly expressed in human carcinomas and can act with either tumor-promoting or tumor-suppressing functions. miR-19a is one of the most investigated miRNAs, whose dysregulated expression is involved in different types of tumors and has been potentially associated with the prognosis of cancer patients. The aim of this review is to investigate the role of miR-19a in cancer, highlighting its involvement in cell proliferation, cell growth, cell death, tissue invasion and migration, as well as in angiogenesis. On these bases, miR-19a could prove to be truly useful as a potential diagnostic, prognostic, and therapeutic marker.

ANTs and cancer: Emerging pathogenesis, mechanisms, and perspectives

Adenine nucleotide translocases (ANTs) are a class of transporters located in the inner mitochondrial membrane that not only couple processes of cellular productivity and energy expenditure, but are also involved in the composition of the mitochondrial membrane permeability transition pore (mPTP). The function of ANTs has been found to be most closely related to their own conformational changes. Notably, as multifunctional proteins, ANTs play a key role in oncogenesis, which provides building blocks for tumor anabolism, control oxidative phosphorylation and glycolysis homeostasis, and govern cell death. Thus, ANTs constitute promising targets for the development of novel anticancer agents. Here, we review the recent findings regarding ANTs and their important mechanisms in cancer, with a focus on the therapeutic potential of targeting ANTs for cancer therapy.

Drosophila melanogaster Mitochondrial Carriers: Similarities and Differences with the Human Carriers

Mitochondrial carriers are a family of structurally related proteins responsible for the exchange of metabolites, cofactors and nucleotides between the cytoplasm and mitochondrial matrix. The in silico analysis of the Drosophila melanogaster genome has highlighted the presence of 48 genes encoding putative mitochondrial carriers, but only 20 have been functionally characterized. Despite most Drosophila mitochondrial carrier genes having human homologs and sharing with them 50% or higher sequence identity, D. melanogaster genes display peculiar differences from their human counterparts: (1) in the fruit fly, many genes encode more transcript isoforms or are duplicated, resulting in the presence of numerous subfamilies in the genome; (2) the expression of the energy-producing genes in D. melanogaster is coordinated from a motif known as Nuclear Respiratory Gene (NRG), a palindromic 8-bp sequence; (3) fruit-fly duplicated genes encoding mitochondrial carriers show a testis-biased expression pattern, probably in order to keep a duplicate copy in the genome. Here, we review the main features, biological activities and role in the metabolism of the D. melanogaster mitochondrial carriers characterized to date, highlighting similarities and differences with their human counterparts. Such knowledge is very important for obtaining an integrated view of mitochondrial function in D. melanogaster metabolism.

Antimicrobial Peptide TP4 Targets Mitochondrial Adenine Nucleotide Translocator 2

Tilapia piscidin (TP) 4 is an antimicrobial peptide derived from Nile tilapia (Oreochromis niloticus), which shows broad-spectrum antibacterial activity and excellent cancer-killing ability in vitro and in vivo. Like many other antimicrobial peptides, TP4 treatment causes mitochondrial toxicity in cancer cells. However, the molecular mechanisms underlying TP4 targeting of mitochondria remain unclear. In this study, we used a pull-down assay on A549 cell lysates combined with LC-MS/MS to discover that TP4 targets adenine nucleotide translocator (ANT) 2, a protein essential for adenine nucleotide exchange across the inner membrane. We further showed that TP4 accumulates in mitochondria and colocalizes with ANT2. Moreover, molecular docking studies showed that the interaction requires Phe1, Ile2, His3, His4, Ser11, Lys14, His17, Arg21, Arg24 and Arg25 residues in TP4 and key residues within the cavity of ANT2. These findings suggest a mechanism by which TP4 may induce mitochondrial dysfunction to disrupt cellular energy metabolism.

The Multifaceted Role of Heme in Cancer

Heme, an iron-containing porphyrin, is of vital importance for cells due to its involvement in several biological processes, including oxygen transport, energy production and drug metabolism. Besides these vital functions, heme also bears toxic properties and, therefore, the amount of heme inside the cells must be tightly regulated. Similarly, heme intake from dietary sources is strictly controlled to meet body requirements. The multifaceted nature of heme renders it a best candidate molecule exploited/controlled by tumor cells in order to modulate their energetic metabolism, to interact with the microenvironment and to sustain proliferation and survival. The present review summarizes the literature on heme and cancer, emphasizing the importance to consider heme as a prominent player in different aspects of tumor onset and progression.

Differential network analysis depicts regulatory mechanisms for hepatocellular carcinoma from diverse backgrounds

Aim: To elucidate the integrative combinational gene regulatory network landscape of hepatocellular carcinoma (HCC) molecular carcinogenesis from diverse background. Materials & methods: Modified gene regulatory network analysis was used to prioritize differentially regulated genes and links. Integrative comparisons using bioinformatics methods were applied to identify potential critical molecules and pathways in HCC with different backgrounds. Results: E2F1 with its surrounding regulatory links were identified to play different key roles in the HCC risk factor dysregulation mechanisms. Hsa-mir-19a was identified as showed different effects in the three HCC differential regulation networks, and showed vital regulatory role in HBV-related HCC. Conclusion: We describe in detail the regulatory networks involved in HCC with different backgrounds. E2F1 may serve as a universal target for HCC treatment.

miR-636: A Newly-Identified Actor for the Regulation of Pulmonary Inflammation in Cystic Fibrosis

Cystic fibrosis (CF) results from deficient CF transmembrane conductance regulator (CFTR) protein activity leading to defective epithelial ion transport. Pulmonary degradation due to excessive inflammation is the main cause of morbidity and mortality in CF patients. By analysing miRNAs (small RNAseq) in human primary air-liquid interface cell cultures, we measured the overexpression of miR-636 in CF patients compared to non-CF controls. We validated these results in explant biopsies and determined that the mechanism underlying miR-636 overexpression is linked to inflammation. To identify specific targets, we used bioinformatics analysis to predict whether miR-636 targets the 3′-UTR mRNA regions of IL1R1 and RANK (two pro-inflammatory cytokine receptors), IKBKB (a major protein in the NF-κB pathway), and FAM13A (a modifier gene of CF lung phenotype implicated in epithelial remodelling). Using bronchial epithelial cells from CF patients to conduct a functional analysis, we showed a direct interaction between miR-636 and IL1R1, RANK, and IKBKB, but not with FAM13A. These interactions led to a decrease in IL1R1 and IKKβ protein expression levels, while we observed an increase in RANK protein expression levels following the overexpression of miR-636. Moreover, NF-κB activity and IL-8 and IL-6 secretions decreased following the transfection of miR-636 mimics in CF cells. Similar but opposite effects were found after transfection with an antagomiR-636 in the same cells. Furthermore, we demonstrated that miR-636 was not regulated by Pseudomonas aeruginosa in our model. We went on to show that miR-636 is raised in the blood neutrophils, but not in the plasma, of CF patients and may have potential as a novel biomarker. Collectively, our findings reveal a novel actor for the regulation of inflammation in CF, miR-636, which is able to reduce constitutive NF-κB pathway activation when it is overexpressed.

A functional polymorphism in the promoter of miR-17-92 cluster is associated with decreased risk of ischemic stroke

Background

The microRNA-17-92 (miR-17-92) cluster is one of the most extensively studied miRNA clusters. Abnormal expression of the cluster has been found to play important role in different kinds of human diseases, including ischemic stroke (IS). The aim of our study was to investigate the association between three polymorphisms (rs1491034, rs9301654 and rs982873) in the promoter of the miR-17-92 cluster and risk of IS.

Methods

Three hundred and ninety-eight patients with IS and 397 control subjects were included. The genotypes of the three polymorphisms were determined by Snapshot SNP genotyping assay. Relative expression of the cluster in peripheral blood mononuclear cells (PBMCs) of cases and controls were examined by quantitative real-time PCR.

Results

Significant association between rs9301654 polymorphism and risk of IS were observed basing on genotype, model and allele analyses (GA vs. AA: adjusted OR = 0.63, 95% CI: 0.41~0.97, P = 0.037; GG vs. AA: adjusted OR = 0.23, 95% CI: 0.07~0.78, P = 0.018; GA + GG vs. AA: adjusted OR = 0.57, 95% CI: 0.38~0.87, P = 0.009; GA + AA vs. GG: adjusted OR = 0.27, 95% CI: 0.08~0.89, P = 0.032; G vs. A: adjusted OR = 0.58, 95% CI: 0.40~0.83). Haplotype analysis showed that TGC and TGT haplotypes were associated with decreased risk of IS (OR = 0.59, 95% CI: 0.40~0.87, P = 0.007 for TGC haplotype; OR = 0.21, 95% CI: 0.06~0.75, P = 0.009 for TGT haplotype). Importantly, we found the expression of miR-17-5p was significant higher while miR-19a-3p was significant lower in patient with IS compared with the control group (P < 0.01), and patients with rs9301654GG or GA genotype displayed lower level of miR-19a-3p compared with the AA genotype (P < 0.01).

Conclusions

Our findings indicated that rs9301654 polymorphism in the promoter of miR-17-92 cluster may be associated with susceptibility of IS in the Chinese population. However, we found that rs9301654 polymorphism and its respective gene expression did not demonstrate consistent association with IS in the Chinese population. Further studies such as gene-gene interaction are warranted to reveal the role of miR-19a and its regulatory genes in the etiology of IS.

Down-regulated lncRNA SLC25A5-AS1 facilitates cell growth and inhibits apoptosis via miR-19a-3p/PTEN/PI3K/AKT signalling pathway in gastric cancer

Mounting evidence has illustrated the vital roles of long non-coding RNAs (lncRNAs in gastric cancer (GC). Nevertheless, the majority of their roles and mechanisms in GC are still largely unknown. In this study, we investigate the roles of lncRNA SLC25A5-AS1 on tumourigenesis and explore its potential mechanisms in GC. The results showed that the expressions of SLC25A5-AS1 in GC were significantly lower than that of adjacent normal tissues, which were significantly associated with tumour size, TNM stage and lymph node metastasis. Moreover, SLC25A5-AS1 could inhibit GC cell proliferation, induce G1/G1 cell cycle arrest and cell apoptosis in vitro, as well as GC growth in vivo. Dual-luciferase reporter assay confirmed the direct interaction between SLC25A5-AS1 and miR-19a-3p, rescue experiment showed that co-transfection miR-19a-3p mimics and pcDNA-SLC25A5-AS1 could partially restore the ability of GC cell proliferation and the inhibition of cell apoptosis. The mechanism analyses further found that SLC25A5-AS1 might act as a competing endogenous RNAs (ceRNA), which was involved in the derepression of PTEN expression, a target gene of miR-19a-3p, and regulate malignant phenotype via PI3K/AKT signalling pathway in GC. Taken together, this study indicated that SLC25A5-AS1 was down-regulated in GC and functioned as a suppressor in the progression of GC. Moreover, it could act as a ceRNA to regulate cellular behaviours via miR-19a-3p/PTEN/PI3K/AKT signalling pathway. Thus, SLC25A5-AS1 might be served as a potential target for cancer therapeutics in GC.

miR-96 exerts carcinogenic effect by activating AKT/GSK-3β/β-catenin signaling pathway through targeting inhibition of FOXO1 in hepatocellular carcinoma

Background

The aim of this research was to investigate the mechanism of miR-96 affecting hepatocellular carcinoma (HCC).

Methods

mRNA and protein expression was detected by qRT-PCR and Western blot, respectively. HepG2 cells were transfected and grouped as follows: miR-NC group, miR-mimics group, NC + Vector group, mimics + Vector group, mimics + FOXO1 group. Luciferase reporter assay was performed. MTT and Transwell assay was conducted. In vivo studies by nude mice were performed. Immunohistochemistry and immunofluorescence was executed.

Results

Up-regulated miR-96 and down-regulated FOXO1 was found in tumor tissues and HepG2 cells (P < 0.01). FOXO1 was directly suppressed by miR-96. Compared with NC + Vector group, mimics + Vector group has higher OD495 value (P < 0.05), higher migration and invasion cells (P < 0.01), larger transplanted tumor volume (P < 0.01), lower FOXO1 positive cell numbers (P < 0.01), higher p-AKT and p-GSK-3β expression (P < 0.01), lower p-β-catenin expression (P < 0.01), more β-catenin expression in the nucleus (P < 0.01). Compared with mimics + Vector group, mimics + FOXO1 group has lower OD495 value (P < 0.05), lower migration and invasion cells (P < 0.01), smaller transplanted tumor volume (P < 0.01), higher FOXO1 positive cells (P < 0.01), lower p-AKT and p-GSK-3β expression (P < 0.01), higher p-β-catenin expression (P < 0.01), less β-catenin expression in the nucleus (P < 0.01).

Conclusion

miR-96 exerts carcinogenic effect by activating AKT/GSK-3β/β-catenin signaling pathway through targeting inhibition of FOXO1 in HCC.

MT1-MMP downregulation via the PI3K/Akt signaling pathway is required for the mechanical stretching-inhibited invasion of bone-marrow-derived mesenchymal stem cells

Mobilization from the bone marrow and the migration of bone-marrow-derived mesenchymal stem cells (BMSCs) through the peripheral circulation to injured tissue sites are regulated by multiple mechanical and chemical factors. We previously demonstrated that mechanical stretching promotes the migration but inhibits the invasion of BMSCs. However, the involved mechanisms, especially the mechanism of stretching-inhibited BMSC invasion, have not been thoroughly elucidated to date. In this study, we found that mechanical stretching with a 10% amplitude at a 1-Hz frequency for 8 hr significantly reduces BMSC invasion and downregulates the expression of membrane type-1 matrix metalloproteinases (MT1-MMP) at both the messenger RNA and protein levels. The overexpression of MT1-MMP restores mechanical stretching-reduced BMSC invasion. Moreover, phosphatidylinositol 3-kinase (PI3K)-dependent Akt phosphorylation in BMSCs was found to be inactivated by mechanical stretching. Pharmacological inhibitors of PI3K/Akt signaling (LY294002 or A443654) reduced the expression of MT1-MMP and impaired BMSC invasion. In addition, the upregulation of Akt phosphorylation by a pharmacological activator (SC79) increased MT1-MMP expression and suppressed mechanical stretching-reduced BMSC invasion. Taken together, our results suggest that mechanical stretching inhibits BMSC invasion by downregulating MT1-MMP expression by suppressing the PI3K/Akt signaling pathway.

Comparison of breast cancer metastasis models reveals a possible mechanism of tumor aggressiveness

In breast cancer patients, the lungs are among the first sites of cancer metastasis, and in nearly one quarter of metastatic patients, the exclusive first event. Two common mouse models mimic breast cancer lung colonization and distal metastasis: an orthotopic model and intravenous (IV) cell injections. Gene expression analysis of pulmonary lesions from these two methods demonstrated high inter-model resemblance. However, microRNA (miRNA) expression profiles were not compared. In this study, we compared the overall miRNA expression profiles (miRNome) of the orthotopic and IV breast cancer metastasis models and identified significant miRNome changes between the two models. Overexpression of the most significant candidate, miR-96 or downregulation of its validated gene-target, ABCE1 reduced cancer cells 2D/3D cell movement and proliferation in vitro, and abated tumor growth and metastasis formation in vivo. Human data analysis further strengthened miR-96/ABCE1 role in breast cancer tumor aggression. Taken together, our results indicate that IV- and orthotopic models differ by their miRNome. Specifically in our study, breast cancer aggressiveness was dictated by miR-96 regulating ABCE1. Overall, miRNome analysis of various metastatic cancer models may lead to the identification of candidate genes critical to metastasis development.

Identification of miRNA and mRNA expression profiles by PCR microarray in hepatitis B virus‑associated hepatocellular carcinoma

The present study aimed to identify differentially expressed microRNAs (miRNAs) and mRNAs in hepatitis B virus‑associated hepatocellular carcinoma (HCC). A total of five HCC tissues and paired adjacent non‑tumor tissues were screened to identify the differentially expressed miRNAs and target mRNAs using polymerase chain reaction microarrays. The interaction between differential miRNA and mRNA expression was concurrently analyzed using bioinformatics methods. A total of 32 differentially expressed miRNAs (four upregulated miRNAs and 28 downregulated miRNAs) and 16 differentially expressed mRNAs (11 upregulated mRNAs and five downregulated mRNAs) were identified. Among these, upregulated hsa‑miRNA (miR)‑96‑5p and hsa‑miR‑18b‑5p suppressed their target mRNAs forkhead box O1 and MET transcriptional regulator MACC1 (MACC1). Downregulation of hsa‑miR‑199a‑5p led to upregulation of its target mRNAs, cyclin dependent kinase 4 and insulin like growth factor 2 (IGF2). The high‑level expression of IGF2 mRNA and cyclin E1 mRNA was due to the low‑level expression of hsa‑miR‑145‑5p, hsa‑miR‑181a‑5p, hsa‑miR‑199a‑5p and hsa‑miR‑223a‑3p, and hsa‑miR‑26a‑5p and hsa‑miR‑26b‑5p, respectively. The low‑level expression of coronin 1A mRNA and MACC1 mRNA was due to overexpression of hsa‑miR‑517a‑3p and hsa‑miR‑18a‑5p, and hsa‑miR‑18b‑5p, respectively. Numerous gene ontology terms were associated with oncogenesis. The most enriched pathways targeted by the dysregulated miRNAs and mRNAs were associated with cancer and oncogenesis pathways. The present data suggested that differential miRNA and mRNA expression is present in HCC. Thus, interactions between certain miRNAs and mRNAs may be involved in the pathogenesis of HCC.

microRNA-19a-3p promotes tumor metastasis and chemoresistance through the PTEN/Akt pathway in hepatocellular carcinoma

microRNA-19a-3p (miR-19a-3p) has been reported to regulate cell proliferation in hepatocellular carcinoma (HCC), but its role in HCC metastasis remains unknown. In this study, miR-19a-3p was noted to be upregulated in HCC specimens and cell lines. Aberrant expression of miR-19a-3p stimulated HCC cell metastasis, and phosphatase and tensin homolog (PTEN) was shown to be a direct target of miR-19a-3p. miR-19a-3p-mediated HCC metastasis was reversed by restoration of PTEN or could be imitated by silencing of PTEN. Modulation of miR-19a-3p also altered expression of phosphorylated Akt, a downstream mediator of PTEN. Moreover, aberrant expression of miR-19a-3p induced sorafenib resistance by regulating the PTEN/Akt pathway. In conclusion, ectopic expression of miR-19a-3p contributes to HCC metastasis and chemoresistance by modulating PTEN expression and the PTEN-dependent pathways.

Screening therapeutic targets of ribavirin in hepatocellular carcinoma

The objective of the present study was to screen the key genes of ribavirin in hepatocellular carcinoma (HCC) and provide novel therapeutic targets for HCC treatment. The mRNA expression datasets of GSE23031 and GSE74656, as well as the microRNA (miRNA) expression dataset of GSE22058 were downloaded from the Gene Expressed Omnibus database. In the GSE23031 dataset, there were three HCC cell lines treated with PBS and three HCC cell lines treated with ribavirin. In the GSE74656 dataset, five HCC tissues and five carcinoma adjacent tissues were selected. In the GSE22058 dataset, 96 HCC tissues and 96 carcinoma adjacent tissues were selected. The differentially expressed genes (DEGs) and differentially expressed miRNAs were identified via the limma package of R. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed with the Database for Annotation, Visualization and Integrated Discovery. The target mRNAs of DEMs were obtained with TargetScan. A total of 559 DEGs (designated DEG-Ribavirin) were identified in HCC cells treated with ribavirin compared with PBS and 632 DEGs (designated DEG-Tumor) were identified in HCC tissues compared with carcinoma adjacent tissues. A total of 220 differentially expressed miRNAs were identified in HCC tissues compared with carcinoma adjacent tissues. In addition, 121 GO terms and three KEGG pathways of DEG-Ribavirin were obtained, and 383 GO terms and 25 KEGG pathways of DEG-Tumor were obtained. A total of five key miRNA-mRNA regulated pairs were identified, namely miR-183→CCNB1, miR-96→DEPDC1, miR-96→NTN4, miR-183→NTN4 and miR-145→NTN4. The present study indicated that certain miRNAs (including miR-96, miR-145 and miR-183) and mRNAs (including NAT2, FBXO5, CCNB1, DEPDC1 and NTN4) may be associated with the effects of ribavirin on HCC. Furthermore, they may provide novel therapeutic targets for HCC treatment.

Effect of miRNA-19a on gastrointestinal motility in rats with functional dyspepsia

The effect of microRNA (miRNA)-19a on gastrointestinal motility in rats with functional dyspepsia was investigated. Fifty adult Sprague-Dawley (SD) rats were randomly divided into 5 groups, 10 rats in each group, one group as the normal group, one group as the model group, and the other three groups were divided into negative control group, miRNA-19a mimic group and miRNA-19a inhibitor group. All rats were intraperitoneally injected with miRNA-19a scramble, miRNA-19a mimic and miRNA-19a inhibitor. Except the normal group, the functional dyspepsia model rat was established by proper clipping tail stimulation. The gastric emptying rate, intestinal propulsive ratio, serum motilin and vasoactive intestinal peptide of rats in each group were measured. The level of miRNA-19a expression in each group was detected by reverse transcription-polymerase chain reaction (RT-PCR). The gastric emptying rate, intestinal propulsive ratio and serum motilin in model group were significantly lower than those in normal group, and vasoactive intestinal peptide was higher in model group than that in normal group (P<0.05). The expression of miRNA-19a in model group was significantly higher than that in normal group (P<0.05). After intraperitoneal injection of miRNA-19a mimic, the expression of miRNA-19a was increased; gastric emptying rate, intestinal propulsive ratio and serum motilin were significantly reduced in model group, and vasoactive intestinal peptide was increased (P<0.05). After intraperitoneal injection of miRNA-19a inhibitor, the expression of miRNA-19a was remarkably decreased; gastric emptying rate, intestinal propulsive ratio and serum motilin were further increased in model group, and vasoactive intestinal peptide was decreased (P<0.05). In conclusion, the expression of miRNA-19a in rats with functional dyspepsia is higher than that in normal rats, and the reduced miRNA-19a expression can ameliorate the gastrointestinal motility in rats with functional dyspepsia.

miR-146a and miR-146b promote proliferation, migration and invasion of follicular thyroid carcinoma via inhibition of ST8SIA4

Follicular thyroid carcinoma (FTC) is a more aggressive form of thyroid cancer than the common papillary type. Alpha-2,8-sialyltransferase (ST8SIA) family members are expressed in various cancers and may be associated with FTC progression. In this study, we measured ST8SIA family expression in two FTC cell lines with different invasive potentials (FTC-133 and FTC-238) and Nthy-ori 3-1 cell lines, as well as FTC and normal thyroid tissues. ST8SIA4 was downregulated in the highly invasive FTC-238 cells and FTC tissues. Additionally, ST8SIA4 inhibited proliferation, migration and invasion of FTC both in vitro and in vivo. miR-146a and miR-146b were previously shown to be upregulated in thyroid carcinoma, and bioinformatics analyses indicated that miR-146a and miR-146b inhibit ST8SIA4. We found that miR-146a and miR-146b were significantly upregulated in FTC and promoted tumour progression. Furthermore, ST8SIA4 restoration decreased the invasiveness of miR-146a/b-overexpressing FTC-133 cells, and ST8SIA4 suppression reversed the effects of miR-146a/b inhibition in FTC-238 cells. We showed that miR-146a/b activated the PI3K-AKT-mTOR signalling pathway at least partially via suppression of ST8SIA4. Thus, our results demonstrate that miR-146a and miR-146b promote proliferation, migration and invasion of FTC via inhibition of ST8SIA4.

Retracted Article: MiR-182-5p and miR-96-5p increased hepatocellular carcinoma cell mobility, proliferation and cisplatin resistance partially by targeting RND3

We investigated whether miR-182-5p or miR-96-5p could increase hepatocellular carcinoma (HCC) development by targeting Rho Family GTPase 3 (RND3) gene expression. The expression levels of miR-182-5p, miR-96-5p and mRNA/protein of RND3 in non-HCC liver tissue, HCC tissue and adjacent tissue specimens were evaluated by RT-qPCR and western blot. Patient-derived HCC cell culture was established, and miR-182-5p or miR-96-5p agomir or antagomir treatment was performed to mimic the overexpression or knockdown of the two miRNAs. HCC cell mobility in vitro was monitored by trans-well migration and invasion assay, while HCC cell growth in vitro was evaluated by cell viability, proliferation and apoptosis assay. HCC cell apoptosis was further investigated by caspase-3/-8/-9 activity assay. MiR-182-5p and miR-96-5p were significantly upregulated in HCC tissue specimens compared with non-HCC or adjacent tissue specimens, inversely correlating to RND3 mRNA expression level. Treatment with miR-182-5p or miR-96-5p agomir significantly reduced RND3 mRNA/protein expression level in HCC cells. MiR-182-5p- or miR-96-5p-targeting RND3 mRNA was verified by luciferase reporter assay and AGO2-RNA immunoprecipitation assay. MiR-182-5p or miR-96-5p agomir treatment significantly rescued HCC cell migration and invasion in vitro that were repressed by RND3 overexpression, during which ROCK1 and ROCK2 inhibition were involved. MiR-182-5p or miR-96-5p agomir treatment also increased HCC cell proliferation and cisplatin resistance in vitro, which could be antagonized by RND3 overexpression or ROCK inhibition. Thus, miR-182-5p and miR-96-5p increased HCC cell mobility, proliferation and cisplatin resistance in vitro partially by targeting RND3.

We investigated whether miR-182-5p or miR-96-5p could increase hepatocellular carcinoma (HCC) development by targeting Rho Family GTPase 3 (RND3) gene expression.

miR-96-5p prevents hepatic stellate cell activation by inhibiting autophagy via ATG7

Activation of hepatic stellate cell (HSC), which is the main source of extracellular matrix, plays a pivotal role in liver fibrogenesis. Autophagy of hepatic stellate cell has been recently implicated in liver fibrosis, but the regulation of hepatic stellate cell autophagy during this process remains poorly understood. Here, we first identified miR-96-5p as an aberrantly expressed miRNA in fibrotic liver tissues. Next, we transfected miR-96-5p mimic into human hepatic stellate cell line LX-2 and observed decreased protein and mRNA levels of α-SMA and Col1A1. In addition, transfection of miR-96-5p mimic significantly reduced autophagy activity of LX-2 cells, while transfection of miR-96-5p inhibitor promoted LX-2 cell autophagy. Moreover, autophagy-related protein 7 (ATG7) was predicted as a potential target of miR-96-5p and luciferase assay confirmed its direct interaction with miR-96-5p. Finally, reintroduction of ATG7 into LX-2 cells reversed miR-96-5p-mediated inhibition of autophagy as well as α-SMA and Col1A1 expression. In conclusion, we demonstrated that miR-96-5p can inhibit hepatic stellate cell activation by blocking autophagy via ATG7. These findings provide new insight into the development of miRNA-based anti-fibrotic strategies.

KEY MESSAGES

• Altered miRNA expression profile is observed in fibrotic liver tissues. • miR-96-5p can inhibit HSC activation. • Autophagy of HSC is repressed by miR-96-5p during activation. • ATG7 is a direct target of miR-96-5p. • ATG7 can rescue miR-96-5p-mediated inhibition of autophagy and HSC activation.

MiR-19a Affects Hepatocyte Autophagy via Regulating lncRNA NBR2 and AMPK/PPARα in D-GalN/Lipopolysaccharide-Stimulated Hepatocytes

This study aims to evaluate the potential involvement and regulatory mechanism of miR-19a in hepatocytes autophagy of acute liver failure (ALF). The in vitro hepatocytes injury model of primary hepatocyte and hepatocytes line HL-7702 was established by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) co-treatment. Relative expression level of miR-19a and NBR2 was determined by qRT-PCR. Protein expression of AMPK/PPARα and autophagy-related gene was determined by Western blot. In hepatic tissue of 20 ALF patients and D-GalN/LPS-stimulated hepatocytes, miR-19a was upregulated and NBR2 was downregulated. D-GalN/LPS stimulation caused the inactivation of AMPK/PPARα signaling and the decrease of autophagy-related LC3-II/LC3-I ratio and beclin-1 expression in hepatocytes. The expression of both AMPK/PPARα and NBR2 were negatively controlled by miR-19a overexpression or knockdown. Moreover, both NBR2 and PPARα were targeted regulated by miR-19a according to luciferase reporter assay. In D-GalN/LPS-stimulated hepatocytes, AMPK activation promoted PPARα expression. AMPK inactivation inhibited the pro-autophagy effect of miR-19a and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. PPARα activation abrogated the anti-autophagy effect of miR-19a mimic and caused the increase of LC3-II/LC3-I ratio and beclin-1 expression. NBR2 knockdown reversed the anti-autophagy impact of miR-19a inhibitor and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. In summary, our data suggested that miR-19a negatively controlled the autophagy of hepatocytes attenuated in D-GalN/LPS-stimulated hepatocytes via regulating NBR2 and AMPK/PPARα signaling. J. Cell. Biochem. 119: 358-365, 2018. © 2017 Wiley Periodicals, Inc.

Macrophages activating chemokine (C-X-C motif) ligand 8/miR-17 cluster modulate hepatocellular carcinoma cell growth and metastasis

Macrophages are a major component of tumor stroma and the infiltrated macrophages in malignant tumor tissues (as called tumor associated macrophages, TAM) play a pivotal role in hepatocellular carcinoma (HCC) progression. However, the molecular mechanisms of macrophages promoting HCC metastasis are poorly understood. The study was to investigate the effects of macrophages on liver cancer cell proliferation and metastasis through chemokine (C-X-C Motif) Ligand 8 (CXCL8). We found that macrophages activated by co-cultured liver cancer cells produced higher levels of CXCL8, which accelerated cell growth and metastasis. The expression of miR-18a and miR-19a (belonging to miR-17 cluster) increased in HCC cells by CXCL8 simulation and led to the enhancement of HCC cell proliferation and metastasis. In a conclusion, HCC cells and macrophages interaction promoted cancer cell proliferation and metastasis through the up-regulation of CXCL8/miR-17 cluster.

MiR-19a regulates the cell growth and apoptosis of osteosarcoma stem cells by targeting PTEN

MicroRNAs are small, endogenous, and non-coding RNAs that play important regulatory roles in multiple biological processes in cancers. Recent evidence has indicated that miR-19a participates in the cancer tumorigenic progression. However, the functional roles of miR-19a in cancer stem cells are still unclear. As the cancer stem cells are considered to be responsible for the tumor recurrence and treatment failure in osteosarcoma, the aim of this study is to investigate the molecular mechanism of miR-19a underlying osteosarcoma tumorigenesis. In this study, we observed significant upregulation of miR-19a in osteosarcoma patients' tumor tissues as well as the osteosarcoma cell lines in vitro. We showed that knockdown of miR-19a by its antisense oligonucleotide (anti-miR-19a) significantly decreased the population of cancer stem cells in osteosarcoma cell lines. Furthermore, we found the miR-19a regulated the cell proliferation, migration, and viability in the human osteosarcoma-cancer stem cells. The gene of phosphatase and tensin homolog deleted on chromosome 10, which is an important tumor suppressor, was found to be directly regulated by miR-19a in human osteosarcoma-cancer stem cells. We demonstrated that knockdown of miR-19a increased the expression of phosphatase and tensin homolog deleted on chromosome 10. As the anti-miR-19a inhibited the phosphatidylinositol 3-kinase/AKT pathway and induced apoptosis of human osteosarcoma-cancer stem cells, the phosphatase and tensin homolog deleted on chromosome 10 small interfering RNA inhibited the effect of it. Meanwhile, the phosphatase and tensin homolog deleted on chromosome 10 small interfering RNA also abolished the effect of anti-miR-19a on inhibiting the cell proliferation, migration, and viability in the human osteosarcoma-cancer stem cells. In conclusion, our findings demonstrated that dysregulation of miR-19a plays critical roles in the osteosarcoma stem cells, at least in part via targeting the phosphatase and tensin homolog deleted on chromosome 10. Knockdown of miR-19a may represent a potential strategy for the osteosarcoma treatment.

The pleiotropic regulation of cyclin D1 by newly identified sesaminol-binding protein ANT2

The expression of cyclin D1 is upregulated in various cancer cells by diverse mechanisms, such as increases in mRNA levels, the promotion of the translation by mammalian target of rapamycin complex 1 (mTORC1) signaling and the protein stabilization. We here show that sesaminol, a sesame lignan, reduces the expression of cyclin D1 with decreasing mRNA expression levels, inhibiting mTORC1 signaling and promoting proteasomal degradation. We subsequently generated sesaminol-immobilized FG beads to newly identify sesaminol-binding proteins. As a consequence, we found that adenine nucleotide translocase 2 (ANT2), the inner mitochondrial membrane protein, directly bound to sesaminol. Consistent with the effects of sesaminol, the depletion of ANT2 caused a reduction in cyclin D1 with decreases in its mRNA levels, mTORC1 inhibition and the proteasomal degradation of its protein, suggesting that sesaminol negatively regulates the function of ANT2. Furthermore, we screened other ANT2-binding compounds and found that the proliferator-activated receptor-γ agonist troglitazone also reduced cyclin D1 expression in a multifaceted manner, analogous to that of the sesaminol treatment and ANT2 depletion. Therefore, the chemical biology approach using magnetic FG beads employed in the present study revealed that sesaminol bound to ANT2, which may pleiotropically upregulate cyclin D1 expression at the mRNA level and protein level with mTORC1 activation and protein stabilization. These results suggest the potential of ANT2 as a target against cyclin D1-overexpressing cancers.

Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. More than 80% of patients with HCC are not good candidates for curative surgical resection due to advanced liver cirrhosis caused by underlying chronic hepatitis virus (B or C) infection. Sorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced HCC. Although, sorafenib currently sets the new standard for advanced HCC treatment, tumor response rates are usually quite low. An understanding of the underlying mechanisms for sorafenib resistance is critical. In the present study, we found that adenine nucleotide translocator 2 (ANT2) was upregulated in sorafenib‑resistant HCC Huh7 cells (Huh7-R) and its overexpression promoted sorafenib resistance. ANT2 induced the formation of cancer-initiating cell (CIC) phenotypes and promoted metastasis-associated traits in the Huh7 cells. Silencing of miR-137 upregulated ANT2 protein expression in the Huh7 cells. miR-137 was downregulated in the Huh7-R cells, compared with that in the Huh7 cells and its restoration reversed sorafenib resistance in the Huh7-R cells. Restoration of miR-137 inhibited formation of CIC traits and attenuated the abilities of migration and invasion in the Huh7-R cells. Moreover, we demonstrated that high-intensity focused ultrasound (HIFU) in unresectable HCC upregulated serum miR-137. Combining HIFU and sorafenib may be a wise option for advanced and unresectable HCC.

Synergistic Antitumor Effect of Sorafenib in Combination with ATM Inhibitor in Hepatocellular Carcinoma Cells

Background: Currently, sorafenib is the only systemic chemotherapy drug for advanced stage Hepatocellular carcinoma (HCC). However, emerging data from some clinical HCC patients indicate that sorafenib alone has only moderate antitumor efficacy, and could not inhibit disease metastasis and progression. KU-55933 is a specific ATM inhibitor, which has pro-apoptotic effect on tumor cells. In this study, we analyzed the synergistic effect of sorafenib and KU-55933 on the proliferation of HCC cell lines. Methods: Three HCC cell lines were treated with sorafenib and KU-55933 alone or combination in vitro to investigate inhibitory effect by MTT and wound healing assay. Epithelial to mesenchymal transition (EMT) phenotype change was investigated after sorafenib and KU-55933 treatment by microscopy. Akt signaling pathway proteins including p-Akt, p-mTOR and p-p70S6K were examined by western blot. In addition, cleaved PARP and autophage-related proteins LC3A/B were detected by western blot. Results: KU-55933 can enhance the effect of sorafenib in inhibiting cell proliferation and migration, overcoming EMT, inducing cell apoptosis via inactivating Akt signaling pathway and inducing autophage. The combination treatment with sorafenib and KU-55933 resulted in a strong synergistic effect in vitro. Conclusion: Our results demonstrate that sorafenib combined with KU-55933 treatment does effectively inhibit proliferation of HCC cell lines synergistically. These data suggests that KU-55933 may be a promising chemosensitizer to sorafenib in the treatment of HCC.

Promotive effects of bone morphogenetic protein 2 on angiogenesis in hepatocarcinoma via multiple signal pathways

The effects of Bone morphogenetic protein 2 (BMP-2) on the angiogenesis of hepatocellular carcinoma have not yet been observed and its molecular mechanisms is not clear. We first constructed the recombinant lentivirus vectors expressing small hairpin RNA against BMP-2 gene (LV-SH-BMP2) and the recombinant lentivirus vectors over-expressing BMP-2 (overexpression-LV-BMP2), and then the two recombinant lentivirus vectors were respectively transfected into Hep G2 cells. The Hep G2 cells transfected with LV-SH-BMP2 or overexpression-LV-BMP2 were respectively co-cultured with human umbilical vein endothelial cells (HUVECs) to observe the effects of BMP-2 on HUVECs. The effect of BMP-2 on tumor microvessel density (MVD) was examined. The abilities of proliferation, migration and angiogenesis were significantly inhibited in the HUVECs co-cultured with BMP-2 knockdown Hep G2 (all P < 0.05), but significantly enhanced in the HUVECs co-cultured with BMP-2 overexpression Hep G2 (all P < 0.05). MVD was significantly increased in overexpression-LV-BMP2-transfected Hep G2 tumor, but decreased in LV-SH-BMP2-transfected Hep G2 tumors. The protein expressions of VEGF, p-P38, p-ERK, p-AKT, p-m-TOR were significantly increased after BMP-2 over-expression, or significantly decreased after BMP-2 knockdown (all P < 0.05). These results reveal that BMP-2 can enhance HUVEC proliferation, migration and angiogenesis through P38, ERK and Akt/m-TOR pathway.