Lentiviral-mediated miRNA against osteopontin suppresses tumor growth and metastasis of human hepatocellular carcinoma

HHLA2 promotes hepatoma cell proliferation, migration, and invasion via SPP1/PI3K/AKT signaling pathway

Hepatocellular carcinoma (HCC) stands as one of the most malignant tumors characterized by poor prognosis and high mortality rates. Emerging evidence underscores the crucial role of the B7 protein family in various cancers, including HCC. However, the involvement of the human endogenous retrovirus H long-terminal repeat-associated protein 2 (HHLA2, or B7-H5) in HCC remains unclear. Immunohistochemistry was employed to assess the differential expression of HHLA2 between HCC and normal liver tissues. A battery of assays, including CCK8, EdU, tablet clone-forming, Transwell, and wound healing assays, were conducted to elucidate the function and potential mechanisms of HHLA2 in the malignant biological behaviors of HCC. Additionally, a xenograft mouse model was established to evaluate the tumorigenicity of hepatoma cell lines exhibiting different HHLA2 expression levels in vivo. Western blot analysis was used to analyze HHLA2, secretory phosphoprotein 1 (SPP1), and PI3K/AKT/mTOR levels. HHLA2 exhibited elevated expression in HCC tissues, correlating with poor tumor differentiation and shortened overall survival in HCC patients. In vitro experiments demonstrated that HHLA2 overexpression (OE) promoted the proliferation, migration, and invasion of hepatoma cells, while in vivo experiments revealed that HHLA2 OE enhanced HCC tumor growth. Conversely, inhibition of HHLA2 expression yielded the opposite effect. Downregulation of SPP1 inhibited the proliferation, migration, and invasion induced by HHLA2 OE, and this effect was linked to the PI3K/AKT/mTOR signaling pathway. Our findings indicate that HHLA2 promotes the proliferation, migration, and invasion of hepatoma cells via the SPP1/PI3K/AKT signaling pathway, establishing it as a potential therapeutic target for HCC.

Osteopontin in cancer

Osteopontin (OPN) is a heavily post-translationally modified protein with a molecular weight of 44-70 kDa, depending on the degree of glycosylation. OPN is involved in various biological processes, including bone remodeling, immune response, cell adhesion, migration, and survival. It is essential for controlling osteoclast and osteoblast activity for maintaining bone mass and bone strength. Additionally, OPN has been linked to cardiovascular, inflammatory illnesses, as well as the onset and progression of cancer. OPN is a multifunctional protein that can interact with a variety of cell surface receptors, such as integrins, CD44, the urokinase-type plasminogen activator receptor (uPAR), as well as extracellular matrix (ECM) components (e.g. collagen and hydroxyapatite). These interactions contribute to its wide range of biological functions in general and has significant implications for bone biology, immunology and cancer, specifically. In this chapter, we summarize the structure of OPN with a focus on its molecular mechanisms of action in various cancers.

Multi-cohort validation study of a four-gene signature for risk stratification and treatment response prediction in hepatocellular carcinoma

BACKGROUND

The intricate molecular landscape of hepatocellular carcinoma (HCC) presents a significant challenge to achieving precise risk stratification through clinical genetic testing. At present, there is a paucity of robust gene signatures that could assist clinicians in making clinical decisions for patients with HCC.

METHODS

We obtained gene expression profiles of patients with HCC from 20 independent cohorts available in public databases. A gene signature was developed by employing two machine learning algorithms. In addition to validating the signature with high-throughput data in public cohorts, we external validated the signature in 64 HCC cases by RT-PCR method. We compared genomic, transcriptomic and proteomic features between different subgroups. We also compared our signature to 130 gene signatures that have already been published.

RESULTS

We developed a novel four-gene signature, designated as HCC4, that demonstrates significant potential for the prediction of survival outcomes in more than 1300 patients with HCC. The HCC4 also has potential for predicting recurrence and tumor volume doubling time, assessing transcatheter arterial chemoembolization and immunotherapy responses, and non-invasive detection of HCC. The high HCC4 score group shows a higher frequency of mutations in genes TP53, RB1 and TSC1/2, as well as increased activity of cell-cycle, glycolysis and hypoxia signaling pathways, higher cancer stemness score, and lower lipid metabolism activity. In seven HCC cohorts, HCC4 exhibited a higher average C-index in predicting overall survival compared to the 130 signatures previously published. Drug screening indicated that patients with high HCC4 scores were more sensitive to agents targeting AURKA, TUBB, JMJD6 and KIFC1.

CONCLUSIONS

Our findings demonstrated that HCC4 is a powerful tool for improving risk stratification and for identifying HCC patients who are most likely to benefit from TACE treatment, immunotherapy, and other experimental therapies.

Single-cell mapping reveals several immune subsets associated with liver metastasis of pancreatic ductal adenocarcinoma

BACKGROUND

Identifying a metastasis-correlated immune cell composition within the tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) will help to develop promising and innovative therapeutic strategies. However, the dynamics of immune cell lineages in the TME of advanced PDAC remains elusive.

METHODS

Twenty-six samples from 11 patients (including 11 primary tumor tissues, 10 blood, and 5 lymph nodes) with different stages were used to develop a multiscale immune profile. High-dimensional single-cell analysis with mass cytometry was performed to search for metastasis-correlated immune changes in the microenvironment. The findings were further validated by published single-cell RNA sequencing (scRNA-seq) data and multiplex fluorescent immunohistochemistry.

FINDINGS

High-dimensional single-cell profiling revealed that the three immune-relevant sites formed a distinct immune atlas. Interestingly, the PDAC microenvironment with the potential for metastatic spread to the liver was characterized by a decreased proportion of CD103+PD-1+CD39+ T cells with cytotoxic and exhausted functional status and an increased proportion of CD73+ macrophages. Analysis of scRNA-seq data of PDAC further confirmed the identified subsets and revealed strong potential interactions via various ligand-receptor pairs between the identified T subsets and the macrophages. Moreover, stratified patients with different immune compositions correlated with clinical outcomes of PDAC.

CONCLUSIONS

Our study uncovered metastasis-correlated immune changes, suggesting that ecosystem-based patient classification in PDAC will facilitate the identification of candidates likely to benefit from immunotherapy.

FUNDING

This work was supported by the National Key Research and Development Program of China, the Shanghai International Science and Technology Collaboration Program, the Shanghai Sailing Program, and the Key Laboratory of diagnosis and treatment of severe hepato-pancreatic diseases of Zhejiang Province.

Gene Therapy for High Grade Glioma: The Clinical Experience

INTRODUCTION

High-grade gliomas (HGG) are the most common malignant primary brain tumors in adults, with a median survival of ~18 months. The standard of care (SOC) is maximal safe surgical resection, and radiation therapy with concurrent and adjuvant temozolomide. This protocol remains unchanged since 2005, even though HGG median survival has marginally improved.

AREAS COVERED

Gene therapy was developed as a promising approach to treat HGG. Here, we review completed and ongoing clinical trials employing viral and non-viral vectors for adult and pediatric HGG, as well as the key supporting preclinical data.

EXPERT OPINION

These therapies have proven safe, and pre- and post-treatment tissue analyses demonstrated tumor cell lysis, increased immune cell infiltration, and increased systemic immune function. Although viral therapy in clinical trials has not yet significantly extended the survival of HGG, promising strategies are being tested. Oncolytic HSV vectors have shown promising results for both adult and pediatric HGG. A recently published study demonstrated that HG47Δ improved survival in recurrent HGG. Likewise, PVSRIPO has shown survival improvement compared to historical controls. It is likely that further analysis of these trials will stimulate the development of new administration protocols, and new therapeutic combinations that will improve HGG prognosis.

MicroRNAs in T Cell-Immunotherapy

MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.

CXCR4-guided liposomes regulating hypoxic and immunosuppressive microenvironment for sorafenib-resistant tumor treatment

Clinical sorafenib treatment could activate C-X-C receptor type 4 (CXCR4)/stromal source factor-1α (SDF-1α) axis to aggravate intra-tumoral hypoxia of hepatocellular carcinoma (HCC), which further leads to progression, invasion, metastasis, and immunosuppression of tumors and in return causes resistance to sorafenib therapy. Therefore, a multi-functional oxygen delivery nanoplatform was rationally constructed based on an oxygen-saturated perfluorohexane (PFH)-cored liposome, with the CXCR4 antagonist LFC131 peptides modifying on the surface to simultaneously deliver sorafenib and the CSF1/CSF1R inhibitor PLX3397 (named PFH@LSLP) for sorafenib-resistant HCC treatment. The PFH@LSLP was developed to overcome sorafenib resistance by synergistic effects of the following 3 roles: 1) the O₂-saturated PFH core could alleviate the tumor hypoxia by O₂ supply; 2) the LFC131 peptide recognized the hypoxia-related overexpressed CXCR4 and then blocked SDF-1α/CXCR4 axis to re-sensitize the HCC cells to sorafenib; 3) PLX3397 activated the immune responses via inhibiting the CSF1/CSF1R pathway in TAMs, further enhanced CD8⁺ T cell infiltration to reverse immunosuppression in tumors. Antitumor performance on H22 tumor-bearing mice and HCC patient-derived tumor xenograft (PDX) model showed that PFH@LSLP could overcome sorafenib resistance by synergistic effect of hypoxia attenuation, resistance-related gene regulation, and immune-microenvironment modification.

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PFH@LSLP was developed to overcome sorafenib resistance.

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LFC131 peptide blocked SDF-1α/CXCR4 to sensitize sorafenib.

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PLX3397 blocked CSF1/CSF1R to activate immune response.

A New Inflammation-Related Risk Model for Predicting Hepatocellular Carcinoma Prognosis

Background

Hepatocellular carcinoma (HCC) is characterized by a poor prognosis. Inflammation has a vital role in the formation and development of HCC. However, the prediction of HCC prognosis using inflammation-related genes (IRGs) remains elusive. In this study, we constructed a new IRG risk model to predict the HCC prognosis.

Results

HCC-related RNA expression profiles and their corresponding clinical data were downloaded from TCGA and ICGC databases to explore the IRGs' predicting ability. Seven hundred thirty-seven IRGs from GeneCards were used as candidate genes to construct the model. The associations of overall survival (OS) with IRGs were evaluated using the log-rank test and univariate Cox analysis, and 32 out of 737 IRGs showed predicting the potential for HCC prognosis. These IRGs were further analyzed using the least absolute shrinkage and selection operator (LASSO) and multivariate Cox analyses. Finally, 6 IRGs were included in an IRG risk model. Based on the cut-off of the risk score calculated according to the IRG risk model, HCC samples were divided into the high-risk and the low-risk groups. The OS of patients was lower in the high-risk group than in the low-risk group (P < 0.05). The area under the receiver operating characteristic curve (AUC) of the risk score was 0.78 for 3-year survival. Univariate Cox and multivariate Cox analyses revealed that the risk score was an independent risk factor for HCC prognosis. The KEGG and GO enrichment analysis results further showed that the risk scores were closely related to inflammatory and immune pathways. In addition, the ssGSEA demonstrated that several immune cells and some immune-related pathways were negatively correlated with the risk score.

Conclusions

The new IRG risk score was an independent risk factor for HCC prognosis and could be used to assess the immune status of the HCC microenvironment.

MicroRNAs as therapeutic targets in breast cancer metastasis

Breast cancer is a complex disease with multiple risk factors involved in its pathogenesis. Among these factors, microRNAs are considered for playing a fundamental role in the development and progression of malignant breast tumors. In recent years, various studies have demonstrated that several microRNAs exhibit increased or decreased expression in metastatic breast cancer, acting as indicators of metastatic potential in body fluids and tissue samples. The identification of these microRNA expression patterns could prove instrumental for the development of novel therapeutic molecules that either mimic or inhibit microRNA action. Additionally, an efficient delivery system mediated by viral vectors, nonviral carriers, or scaffold biomaterials is a prerequisite for implementing microRNA-based therapies; therefore, this review attempts to highlight essential microRNA molecules involved in the metastatic process of breast cancer and discuss recent advances in microRNA-based therapeutic approaches with potential future applications to the treatment sequence of breast cancer.

Osteopontin promotes hepatocellular carcinoma progression through inducing JAK2/STAT3/NOX1-mediated ROS production

Osteopontin (OPN) is a multifunctional cytokine that can impact cancer progression. Therefore, it is crucial to determine the key factors involved in the biological role of OPN for the development of treatment. Here, we investigated that OPN promoted hepatocellular carcinoma (HCC) cell proliferation and migration by increasing Reactive oxygen species (ROS) production and disclosed the underlying mechanism. Knockdown of OPN suppressed ROS production in vitro and in vivo, whereas treatment with human recombinant OPN produced the opposite effect. N-Acetyl-L-cysteine (NAC, ROS scavenger) partially blocked HCC cell proliferation and migration induced by OPN. Mechanistically, OPN induced ROS production in HCC cells by upregulating the expression of NADPH oxidase 1 (NOX1). NOX1 knockdown in HCC cells partially abrogated the cell proliferation and migration induced by OPN. Moreover, inhibition of JAK2/STAT3 phosphorylation effectively decreased the transcription of NOX1, upregulated by OPN. In addition, NOX1 overexpression increased JAK2 and STAT3 phosphorylation by increasing ROS production, creating a positive feedback loop for stimulating JAK2/STAT3 signaling induced by OPN. This study for the first time demonstrated that HCC cells utilized OPN to generate ROS for tumor progression, and disruption of OPN/NOX1 axis might be a promising therapeutic strategy for HCC.

Role of Hepatocyte-Derived Osteopontin in Liver Carcinogenesis

Osteopontin (OPN) expression correlates with tumor progression in many cancers, including hepatocellular carcinoma (HCC); however, its role in the onset of HCC remains unclear. We hypothesized that increased hepatocyte‐derived OPN is a driver of hepatocarcinogenesis. Analysis of a tissue microarray of 366 human samples revealed a continuous increase in OPN expression during hepatocarcinogenesis. In patients with cirrhosis, a transcriptome‐based OPN correlation network was associated with HCC incidence along 10 years of follow‐up, together with messenger RNA (mRNA) signatures of carcinogenesis. After diethylnitrosamine (DEN) injection, mice with conditional overexpression of Opn in hepatocytes (Opn^Hep transgenic [Tg]) showed increased tumor burden. Surprisingly, mice with conditional ablation of Opn in hepatocytes (Opn^ΔHep) expressed a similar phenotype. The acute response to DEN was reduced in Opn^ΔHep, which also showed more cancer stem/progenitor cells (CSCs, CD44⁺AFP⁺) at 5 months. CSCs from Opn^Hep Tg mice expressed several mRNA signatures known to promote carcinogenesis, and mRNA signatures from Opn^Hep Tg mice were associated with poor outcome in human HCC patients. Treatment with rOPN had little effect on CSCs, and their progression to HCC was similar in Opn^−/− compared with wild‐type mice. Finally, ablation of Cd44, an OPN receptor, did not reduce tumor burden in Cd44^−/−Opn^Hep Tg mice. Conclusions: Hepatocyte‐derived OPN acts as a tumor suppressor at physiological levels by controlling the acute response to DEN and the presence of CSCs, while induction of OPN is pro‐tumorigenic. This is primarily due to intracellular events rather that by the secretion of the protein and receptor activation.

Tumor-associated macrophages (TAMs)-derived osteopontin (OPN) upregulates PD-L1 expression and predicts poor prognosis in non-small cell lung cancer (NSCLC)

Background

Programmed cell death ligand 1 (PD‐L1) is widely known as an immune checkpoint molecule in tumor cells. Osteopontin (OPN) is expressed by both tumor cells and tumor‐associated macrophages (TAMs), and both autocrine and paracrine of OPN are considered to be involved in tumor metastasis, proliferation and immunosuppression. However, little is known about the relationship between OPN expressed in TAMs (TOPN) and PD‐L1 in non‐small cell lung cancer (NSCLC).

Methods

Tissue microarray was used to detect the expression of TOPN, TAMs and PD‐L1 by multiple quantitative fluorescence staining in 509 NSCLC patients undergoing complete pulmonary resection. The correlations between TOPN, PD‐L1 and clinicopathological data were analyzed. An in vitro coculture system was established to investigate the crosstalk between TOPN and neoplastic PD‐L1. In vivo, the intrinsic features of PD‐L1 in NSCLC xenografts were evaluated after being coinjected with OPN‐positive TAMs, and a series of key cytokines and chemokines were detected in the tumor microenvironment.

Results

A positive association between the TOPN and PD‐L1 expression in tumor tissues from 509 patients with NSCLC was verified. In addition, TOPN and PD‐L1 were independent prognostic factors for overall survival (OS) and disease‐free survival (DFS) of NSCLC patients. Moreover, TOPN upregulated PD‐L1 expression in NSCLC cells through the nuclear factor‐κB (NF‐κB) pathway in vitro TOPN induced the PD‐L1 expression promoted the tumor growth in tumor‐bearing mice, altering immune‐related cytokines and chemokines.

Conclusions

TOPN regulates PD‐L1 expression through the NF‐κB pathway in NSCLS, which is a potential independent biomarker and target for prognosis as well as immunotherapy.

Osteopontin Takes Center Stage in Chronic Liver Disease

Osteopontin (OPN) was first identified in 1986. The prefix osteo- means bone; however, OPN is expressed in other tissues, including liver. The suffix -pontin means bridge and denotes the role of OPN as a link protein within the extracellular matrix. While OPN has well-established physiological roles, multiple "omics" analyses suggest that it is also involved in chronic liver disease. In this review, we provide a summary of the OPN gene and protein structure and regulation. We outline the current knowledge on how OPN is involved in hepatic steatosis in the context of alcoholic liver disease and non-alcoholic fatty liver disease. We describe the mechanisms whereby OPN participates in inflammation and liver fibrosis and discuss current research on its role in hepatocellular carcinoma and cholangiopathies. To conclude, we highlight important points to consider when doing research on OPN and provide direction for making progress on how OPN contributes to chronic liver disease.

The interaction between cancer associated fibroblasts and tumor associated macrophages via the osteopontin pathway in the tumor microenvironment of hepatocellular carcinoma

BACKGROUND

Cancer-tumor associated macrophage (TAM)-cancer associated fibroblast (CAF) interactions are an important factor in the tumor microenvironment of hepatocellular carcinoma.

MATERIALS AND METHODS

Hepatic stellate cells (HSCs) were cultured with cancer cell-conditioned medium (Ca.-CM), TAM-CM and CAF-CM, and the expression of CAF markers were evaluated by RT-PCR. Whether HSCs cultured with Ca.-CM, TAM-CM and CAF-CM contributed to the enhanced malignancy of cancer cells was examined using proliferation, invasion and migration assays. Furthermore, the differences between these three types of CM were evaluated using cytokine arrays.

RESULTS

HSCs cultured with Ca.-CM, TAM-CM and CAF-CM showed significantly increased mRNA expression of αSMA, FAP and IL-6. All HSCs cultured with each CM exhibited significantly increased proliferation, invasion and migration of cancer cells. The osteopontin concentration was significantly higher in HSCs cultured with TAM-CM than the other CAF-CMs. Osteopontin inhibition significantly reduced osteopontin secretion from HSCs cultured with TAM-CM and suppressed the proliferation and invasion of cancer cells enhanced by HSCs cultured with TAM-CM.

CONCLUSIONS

We observed enhanced osteopontin secretion from TAMs, and this increased osteopontin further promoted osteopontin secretion from HSCs cultured with TAM-CM, leading to increased malignancy. For the first time, we demonstrated the importance of cancer-TAM-CAF interactions via osteopontin in hepatocellular carcinoma.

Artificial miRNAs as therapeutic tools: Challenges and opportunities

RNA interference (RNAi) technology has been used for almost two decades to study gene functions and in therapeutic approaches. It uses cellular machinery and small, designed RNAs in the form of synthetic small interfering RNAs (siRNAs) or vector-based short hairpin RNAs (shRNAs), and artificial miRNAs (amiRNAs) to inhibit a gene of interest. Artificial miRNAs, known also as miRNA mimics, shRNA-miRs, or pri-miRNA-like shRNAs have the most complex structures and undergo two-step processing in cells to form mature siRNAs, which are RNAi effectors. AmiRNAs are composed of a target-specific siRNA insert and scaffold based on a natural primary miRNA (pri-miRNA). siRNAs serve as a guide to search for complementary sequences in transcripts, whereas pri-miRNA scaffolds ensure proper processing and transport. The dynamics of siRNA maturation and siRNA levels in the cell resemble those of endogenous miRNAs; therefore amiRNAs are safer than other RNAi triggers. Delivered as viral vectors and expressed under tissue-specific polymerase II (Pol II) promoters, amiRNAs provide long-lasting silencing and expression in selected tissues. Therefore, amiRNAs are useful therapeutic tools for a broad spectrum of human diseases, including neurodegenerative diseases, cancers and viral infections. Recent reports on the role of sequence and structure in pri-miRNA processing may contribute to the improvement of the amiRNA tools. In addition, the success of a recently initiated clinical trial for Huntington's disease could pave the way for other amiRNA-based therapies, if proven effective and safe. This article is categorized under: RNA Processing > Processing of Small RNAs Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action RNA in Disease and Development > RNA in Disease.

Sox9/INHBB axis-mediated crosstalk between the hepatoma and hepatic stellate cells promotes the metastasis of hepatocellular carcinoma

The activation of hepatic stellate cells (HSCs) and liver fibrosis in the peri-tumoral tissue contributes to the progression of hepatocellular carcinoma (HCC). However, the mechanisms underlying the crosstalk between hepatoma and peri-tumoral HSCs remain elusive. We found that the Sox9/INHBB axis is upregulated in HCC and is associated with tumor metastasis. Using gain- and loss-of-function approaches, we revealed that the Sox9/INHBB axis promotes the growth and metastasis of an orthotopic HCC tumor by activating the peri-tumoral HSCs. Mechanistically, Sox9 induces INHBB expression by directly binding to its enhancer, thus aiding in the secretion of activin B from hepatoma cells, and in turn, promoting the activation of the surrounding HSCs through activin B/Smad signaling. Furthermore, inhibition of activin B/Smad singaling attenuates the fibrotic response in the peri-tumoral tissue and decreases the incidence of metastasis. Finally, clinical analyses indicated a positive correlation between Sox9 and INHBB expression in HCC specimens and identified the Sox9/INHBB axis as a positive regulator of liver fibrosis. In conclusion, Sox9/INHBB axis-mediated crosstalk between hepatoma cells and HSCs induces a fertile environment favoring HCC metastasis, thereby exhibiting as a potential therapeutic target.

Circulating biomarkers for early detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is estimated to be the fourth leading cause of cancer-related deaths worldwide. HCC patients face a dismal prognosis because symptoms usually appear in an advanced stage of disease. The detection of early stage HCC allows for curative surgical treatment and therefore saves lives. Specific non-invasive or diagnostic markers for HCC may represent a valuable tool for detecting these tumors at an early stage. The clinically most established serological biomarker alpha-fetoprotein shows only limited diagnostic performance, however novel candidate biomarkers and biomarker panels for detecting HCC at early stages of development are being studied. In this review we will discuss the findings of these studies.

Integrated analysis reveals critical glycolytic regulators in hepatocellular carcinoma

Background

Cancer cells primarily utilize aerobic glycolysis for energy production, a phenomenon known as the Warburg effect. Increased aerobic glycolysis supports cancer cell survival and rapid proliferation and predicts a poor prognosis in cancer patients.

Methods

Molecular profiles from The Cancer Genome Atlas (TCGA) cohort were used to analyze the prognostic value of glycolysis gene signature in human cancers. Gain- and loss-of-function studies were performed to key drivers implicated in hepatocellular carcinoma (HCC) glycolysis. The molecular mechanisms underlying Osteopontin (OPN)-mediated glycolysis were investigated by real-time qPCR, western blotting, immunohistochemistry, luciferase reporter assay, and xenograft and diethyl-nitrosamine (DEN)-induced HCC mouse models.

Results

Increased glycolysis predicts adverse clinical outcome in many types of human cancers, especially HCC. Then, we identified a handful of differentially expressed genes related to HCC glycolysis. Gain- and loss-of-function studies showed that OPN promotes, while SPP2, LECT2, SLC10A1, CYP3A4, HSD17B13, and IYD inhibit HCC cell glycolysis as revealed by glucose utilization, lactate production, and extracellular acidification ratio. These glycolysis-related genes exhibited significant tumor-promoting or tumor suppressive effect on HCC cells and these effects were glycolysis-dependent. Mechanistically, OPN enhanced HCC glycolysis by activating the αvβ3-NF-κB signaling. Genetic or pharmacological blockade of OPN-αvβ3 axis suppressed HCC glycolysis in xenograft tumor model and hepatocarcinogenesis induced by DEN.

Conclusions

Our findings reveal crucial determinants for controlling the Warburg metabolism in HCC cells and provide a new insight into the oncogenic roles of OPN in HCC.

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.

Aberrant Scinderin Expression Correlates With Liver Metastasis and Poor Prognosis in Colorectal Cancer

Many genes and mutations have been reported for colorectal cancer (CRC); however, very few have been associated with colorectal cancer liver metastasis (CRLM). We performed gene expression profiling experiments to identify genetic markers for CRLM and elucidate the molecular mechanisms. Microarray experiments were performed on CRC primary tumor samples with or without liver metastasis (LM) using the Affymetrix U133 plus 2.0 GeneChip Array. A new identified gene-scinderin (SCIN) was overexpressed with synchronous LM at both the RNA level evaluated with quantitative real-time PCR and protein level evaluated with immunohistochemistry and also with short overall survival analyzed with Kaplan-Meier method. With multivariate analysis indicated that SCIN served as an independent poor prognostic predictor for CRC patients. Disease-free survival was also significantly lower in SCIN overexpressing CRC patients with metachronous LM. In addition, SCIN knockdown significantly reduced cell proliferation, induced cell cycle arrest, and promoted the expression of some cell cycle apoptosis-related protein. Moreover, the DIAPH1, STAT3, CDK2, CDK4, and EGFR levels were downregulated, whereas CDKN2B and COL4A1 were upregulated in DLD-1-shSCIN cells by microarray analysis compared with DLD-1 shCon cells. These findings revealed that SCIN may serve as an important predictor of CRLM and poor outcome for CRC patients. SCIN may be a potential therapeutic target in human CRC. However, translation of its roles into clinical practice will require further investigation and additional experimental validation.

DNA methylation-driven genes for constructing diagnostic, prognostic, and recurrence models for hepatocellular carcinoma

In this study, we performed a comprehensively analysis of gene expression and DNA methylation data to establish diagnostic, prognostic, and recurrence models for hepatocellular carcinoma (HCC).

Methods: We collected gene expression and DNA methylation datasets for over 1,200 clinical samples. Integrated analyses of RNA-sequencing and DNA methylation data were performed to identify DNA methylation-driven genes. These genes were utilized in univariate, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses to build a prognostic model. Recurrence and diagnostic models for HCC were also constructed using the same genes.

Results: A total of 123 DNA methylation-driven genes were identified. Two of these genes (SPP1 and LCAT) were chosen to construct the prognostic model. The high-risk group showed a markedly unfavorable prognosis compared to the low-risk group in both training (HR = 2.81; P < 0.001) and validation (HR = 3.06; P < 0.001) datasets. Multivariate Cox regression analysis indicated the prognostic model to be an independent predictor of prognosis (P < 0.05). Also, the recurrence model successfully distinguished the HCC recurrence rate between the high-risk and low-risk groups in both training (HR = 2.22; P < 0.001) and validation (HR = 2; P < 0.01) datasets. The two diagnostic models provided high accuracy for distinguishing HCC from normal samples and dysplastic nodules in the training and validation datasets, respectively.

Conclusions: We identified and validated prognostic, recurrence, and diagnostic models that were constructed using two DNA methylation-driven genes in HCC. The results obtained by integrating multidimensional genomic data offer novel research directions for HCC biomarkers and new possibilities for individualized treatment of patients with HCC.

Disruption of tumour-associated macrophage trafficking by the osteopontin-induced colony-stimulating factor-1 signalling sensitises hepatocellular carcinoma to anti-PD-L1 blockade

OBJECTIVE

In the tumour microenvironment, critical drivers of immune escape include the oncogenic activity of the tumour cell-intrinsic osteopontin (OPN), the expression of programmed death ligand 1 (PD-L1) and the expansion of tumour-associated macrophages (TAMs). We investigated the feasibility of targeting these pathways as a therapeutic option in hepatocellular carcinoma (HCC) mouse models.

DESIGN

We analysed the number of tumour-infiltrating immune cells and the inflammatory immune profiles in chemically induced liver tumour isolated from wild-type and OPNknockout (KO) mice. In vitro cell cocultures were further conducted to investigate the crosstalk between TAMs and HCC cells mediated by OPN, colony stimulating factor-1 (CSF1) and CSF1 receptor (CSF1R). The in vivo efficacy of anti-PD-L1 and CSF1/CSF1R inhibition was evaluated in OPN overexpressing subcutaneous or orthotopic mouse model of HCC.

RESULTS

The numbers of TAMs, as well as the expression levels of M2 macrophage markers and PD-L1 were significantly decreased, but the levels of cytokines produced by T-helper 1 (Th1) cells were upregulated in tumour tissues from OPN KO mice compared with that from the controls. In addition, we observed a positive association between the OPN and PD-L1 expression, and OPN expression and TAM infiltration in tumour tissues from patients with HCC. We further demonstrated that OPN facilitates chemotactic migration, and alternative activation of macrophages, and promotes the PD-L1 expression in HCC via activation of the CSF1-CSF1R pathway in macrophages. Combining anti-PD-L1 and CSF1R inhibition elicited potent antitumour activity and prolonged survival of OPN^high tumour-bearing mice. Histological, flow cytometric and ELISA revealed increased CD8⁺ T cell infiltration, reduced TAMs and enhanced Th1/Th2 cytokine balance in multiple mouse models of HCC.

CONCLUSIONS

OPN/CSF1/CSF1R axis plays a critical role in the immunosuppressive nature of the HCC microenvironment. Blocking CSF1/CSF1R prevents TAM trafficking and thereby enhances the efficacy of immune checkpoint inhibitors for the treatment of HCC.

Lack of galectin-1 exacerbates chronic hepatitis, liver fibrosis, and carcinogenesis in murine hepatocellular carcinoma model

Chronic liver inflammation (CLI) is a risk factor for development of hepatocellular carcinoma (HCC). Galectin-1 (Gal1) is involved in the regulation of inflammation, angiogenesis, and tumorigenesis, exhibiting multiple anti-inflammatory and protumorigenic activities. We aimed to explore its regulatory role in CLI and HCC progression using an established model of CLI-mediated HCC development, Abcb4 [multidrug-resistance 2 (Mdr2)]-knockout (KO) mice, which express high levels of Gal1 in the liver. We generated double-KO (dKO) Gal1-KO/Mdr2-KO mice on C57BL/6 and FVB/N genetic backgrounds and compared HCC development in the generated strains with their parental Mdr2-KO strains. Loss of Gal1 increased liver injury, inflammation, fibrosis, and ductular reaction in dKO mice of both strains starting from an early age. Aged dKO mutants displayed earlier hepatocarcinogenesis and increased tumor size compared with control Mdr2-KO mice. We found that osteopontin, a well-known modulator of HCC development, and oncogenic proteins Ntrk2 (TrkB) and S100A4 were overexpressed in dKO compared with Mdr2-KO livers. Our results demonstrate that in Mdr2-KO mice, a model of CLI-mediated HCC, Gal1-mediated protection from hepatitis, liver fibrosis, and HCC initiation dominates over its known procarcinogenic activities at later stages of HCC development. These findings suggest that anti-Gal1 treatments may not be applicable at all stages of CLI-mediated HCC.-Potikha, T., Pappo, O., Mizrahi, L., Olam, D., Maller, S. M., Rabinovich, G. A., Galun, E., Goldenberg, D. S. Lack of galectin-1 exacerbates chronic hepatitis, liver fibrosis, and carcinogenesis in murine hepatocellular carcinoma model.

CCN2-MAPK-Id-1 loop feedback amplification is involved in maintaining stemness in oxaliplatin-resistant hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Chemotherapy is an alternative treatment for advanced HCCs, but chemo-resistance prevents cancer therapies from achieving stable and complete responses. Understanding the underlying mechanisms in chemo-resistance is critical to improve the efficacy of HCC.

Methods

The expression levels of Id-1 and CCN2 were detected in large cohorts of HCCs, and functional analyses of Id-1 and CCN2 were performed both in vitro and in vivo. cDNA microarrays were performed to evaluate the alterations of expression profiling of HCC cells with overexpression of CCN2. Finally, the role of downstream signaling of MAPK/Id-1 signaling pathway in oxaliplatin resistance were also explored.

Results

The increased expression of Id-1 and CCN2 were closely related to oxaliplatin resistance in HCC. Upregulation of CCN2 and Id-1 was independently associated with shorter survival and increased recurrence in HCC patients, and significantly enhanced oxaliplatin resistance and promoted lung metastasis in vivo, whereas knock-down of their expression significantly reversed the chemo-resistance and inhibited HCC cell stemness. cDNA microarrays and PCR revealed that Id-1 and MAPK pathway were the downstream signaling of CCN2. CCN2 significantly enhanced oxaliplatin resistance by activating the MAPK/Id-1 signaling pathway, and Id-1 could upregulate CCN2 in a positive feedback manner.

Conclusions

CCN2/MAPK/Id-1 loop feedback amplification is involved in oxaliplatin resistance, and the combination of oxaliplatin with inhibitor of CCN2 or MAPK signaling could provide a promising approach to ameliorating oxaliplatin resistance in HCC.

Electronic supplementary material

The online version of this article (10.1007/s12072-019-09960-5) contains supplementary material, which is available to authorized users.

Differential effects of ginkgol C17:1 on cisplatin-induced cytotoxicity: Protecting human normal L02 hepatocytes versus sensitizing human hepatoma HepG2 cells

Liver cancer is a major healthcare problem and one of the leading causes of cancer-associated mortality in the world. To date, chemotherapy remains a common method for treating cancer and cisplatin is one of the most widely used chemotherapeutics. However, owing to drug resistance and side effects, it is imperative to identify a novel approach to improve the anticancer effect of cisplatin. Auxiliary chemotherapy drugs with minor toxicity to normal cells may represent a novel strategy for cancer therapy. Previous studies have indicated that ginkgol C17:1 exhibits anticancer effects in liver cancer cells in vitro and in vivo. The antitumor activity of ginkgol C17:1 has been reported in combination with cisplatin in human liver cancer cells. Owing to the route of systemic administration, liver cancer cells and normal hepatocytes were exposed to chemotherapeutics and auxiliary chemotherapy drugs. However, the effects of ginkgol C17:1 in normal hepatocytes remain unclear. In the present study, the biological effects of ginkgol C17:1 alone and as co-treatment with cisplatin were compared in human hepatoma cells and normal hepatocytes. Consistently, the results confirmed that in human hepatoma HepG2 cells, ginkgol C17:1 or cisplatin alone induced autophagy and apoptosis. The co-treatment increased cisplatin-induced apoptosis and inhibited cisplatin-induced autophagy. In comparison, the treatments in human normal L02 hepatocytes indicated that ginkgol C17:1 alone induced autophagy, whereas cisplatin alone induced apoptosis. The co-treatment inhibited cisplatin-induced apoptosis, but enhanced autophagy in L02 cells. Further investigation revealed that the AMP-activated protein kinase/serine/threonine protein kinase ULK1 and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathways were involved in the underlying regulatory mechanisms. Taken together, the results of the present study provide the first evidence that ginkgol C17:1 protects normal hepatocytes against cisplatin-induced cytotoxicity while potentiating the anticancer effect of cisplatin chemotherapy. The differential effects on normal and cancer cells suggest that ginkgol C17:1 is a promising candidate for auxiliary chemotherapy.

Periostin involved in the activated hepatic stellate cells-induced progression of residual hepatocellular carcinoma after sublethal heat treatment: its role and potential for therapeutic inhibition

BACKGROUND

Incomplete thermal ablation may induce invasiveness of hepatocellular carcinoma (HCC). Here, we investigated whether activated hepatic stellate cells (HSCs) would accelerate the progression of residual HCC after sublethal heat treatment, and thus sought to identify the potential targets.

METHODS

Hepatocellular carcinoma cells were exposed to sublethal heat treatment and then cultured with the conditioned medium from activated HSCs (HSC-CM). The cell proliferation, migration, invasion and parameters of epithelial-mesenchymal transition (EMT) were analyzed. In vivo tumor progression of heat-treated residual HCC cells inoculated with activated HSCs was studied in nude mice.

RESULTS

HSC-CM significantly enhanced the proliferation, motility, invasion, prominent EMT activation and decreased apoptosis of heat-exposed residual HCC cells. These increased malignant phenotypes were markedly attenuated by neutralizing periostin (POSTN) in HSC-CM. Furthermore, exogenous POSTN administration exerted the similar effects of HSC-CM on heat-treated residual HCC cells. POSTN induced the prominent activation of p52Shc and ERK1/2 via integrin β1 in heat-exposed residual HCC cells. Vitamin D analog calcipotriol blocked POSTN secretion from activated HSCs. Calcipotriol plus cisplatin significantly suppressed the activated HSCs-enhanced tumor progression of heat-treated residual HCC cells via the inhibited POSTN expression and the increased apoptosis.

CONCLUSIONS

Activated HSCs promote the tumor progression of heat-treated residual HCC through the release of POSTN, which could be inhibited by calcipotriol. Calcipotriol plus cisplatin could be used to thwart the accelerated progression of residual HCC after suboptimal heat treatment.

Lentivirus‑mediated microRNA‑26a overexpression in bone mesenchymal stem cells facilitates bone regeneration in bone defects of calvaria in mice

Repair of bone defects presents a serious clinical challenge as it is difficult to restore bone function and regenerate bone loss. In the present study, the effects of lentivirus-mediated transfection of bone marrow mesenchymal stem cells (BMSCs) with microRNA (miR)-26a on bone regeneration were investigated in a mouse bone defect repair model. Marker of proliferation Ki67 (Ki67) staining was employed to detect the cell proliferation capacity and alkaline phosphatase (ALP) staining was used to investigate osteogenic differentiation. A mouse model of cranial bone defects was established. β-tricalcium phosphate biomaterials co-cultured with the transfected BMSCs were implanted into the defect areas of mouse models. Micro-computed tomography, and hematoxylin and eosin and toluidine blue staining, were used to detect bone regeneration in the defect areas and the degradation of scaffolds. miR-26a expression, and the mRNA and protein expression of osteogenesis-associated cytokines, were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis. Separated and cultured BMSCs highly expressed CD29 and CD105, but not CD34 and CD45, as determined by flow cytometry. miR-26a expression and the positive cell rate of Ki67 and ALP staining in BMSCs transfected with pLVTHM-miR-26a were increased. The BMSC and negative control-transfected BMSC groups exhibited increased bone regeneration in the defect areas, increased bone volume of newly formed bones, and elevated mRNA and protein expression of runt-related transcription factor 2 (Runx2) and osteocalcin (OC), compared with the blank group. However, the miR-26a-transfected BMSC group exhibited further increases in bone regeneration and the volume of newly formed bones, and further elevations of the mRNA and protein expression levels of Runx2 and OC. The present findings demonstrated that lentivirus-mediated modification of BMSCs enhanced bone regeneration during the repair of cranial bone defects in mice.

Prognostic value of osteopontin in patients with hepatocellular carcinoma: A systematic review and meta-analysis

PURPOSE

The prognostic value of tissue and serum osteopontin (OPN) in hepatocellular carcinoma (HCC) remain controversial. The aim of present meta-analysis was to evaluate the prognostic value of OPN in patients with HCC.

METHODS

Eligible studies were systematically searched by PubMed, EMBASE, and Google scholar. A meta-analysis of 12 studies included 2117 cases was performed to estimate the association between OPN level and overall survival (OS), disease-free survival (DFS) in HCC patients. Subgroup analyses were also performed in the meta-analysis.

RESULTS

The pooled data of studies showed that high OPN level was significantly associated with poor OS (hazard ratios [HR] 1.84; 95% confidence intervals [CI] 1.54-2.20; P = .000) and DFS (HR 1.67; 95% CI 1.40-1.98; P = .000) in HCC. Furthermore, in subgroup analysis, high tissue based OPN by immunohistochemistry detection and serum-based OPN by enzyme-linked immunosorbent assay (ELISA) detection were both significantly associated with OS (tissue: HR 1.88; 95% CI 1.53-2.31; P < .0001; serum: HR 2.38; 95% CI 1.58-3.59; P < .0001). Simultaneously, we also found that OPN expression was positively associated with stage (odds ratios [OR] 5.68; 95% CI 3.443-7.758), tumor size (Size≤5 cm vs >5 cm; OR 2.001; 95% CI1.036-3.867).

CONCLUSION

The current evidence indicates that OPN could serve as a prognostic biomarker and a potential therapeutic target for HCC.

Osteopontin promotes hepatocellular carcinoma progression via the PI3K/AKT/Twist signaling pathway

The epithelial-mesenchymal transition (EMT) serves critical roles in the migration, invasion and metastasis of human cancer cells. This process is initiated by regulation of E-cadherin expression by the major inducers of EMT. Previous studies reported that osteopontin (OPN) is essential for hepatocellular carcinoma (HCC) metastasis as it facilitates the EMT in HCC. However, the role and clinical significance of OPN as an EMT regulator in HCC remains unknown. The present study revealed that OPN regulated the expression of Twist by activating RAC serine/threonine-protein kinase (Akt), a critical EMT regulator. Interfering with the phosphoinositide 3-kinase (PI3K)/Akt pathway may suppress the expression of Twist enhanced by OPN. Increased Twist levels in HCC were associated with poor survival and tumor recurrence in patients with HCC following surgery. A significant association was observed between OPN expression and Twist levels in HCC, and a combination of these two parameters was revealed to be a more powerful predictor of poor patient prognosis. The findings of the present study indicate that Twist serves an notable role in OPN-mediated metastasis of HCC through activation of the PI3K/Akt pathway. Twist may be a potential therapeutic target for the prevention of HCC metastasis in patients exhibiting high OPN expression.

Osteopontin alters DNA methylation through up-regulating DNMT1 and sensitizes CD133+/CD44+ cancer stem cells to 5 azacytidine in hepatocellular carcinoma

BACKGROUND

In hepatocellular carcinoma (HCC), CD133+/CD44+ cells are one subgroup with high stemness and responsible for metastatic relapse and resistance to treatment. Our previous studies have demonstrated that osteopontin (OPN) plays critical roles in HCC metastasis. We further investigated the molecular mechanism underlying the role of OPN in regulating the stemness of HCC epigenetically and explored possible targeting strategy.

METHODS

CD133+/CD44+ subgroup sorting from HCC cell lines and HCC tissues was used to investigate the effects of OPN knockdown on stemness. iTRAQ and MedIP-sequencing were applied to detect the protein profile and epigenetic modification of CD133+/CD44+ subgroup with or without OPN knockdown. The antitumor effects of 5 Azacytidine were examined in cultured HCC cells and patient derived xenograft (PDX) models.

RESULTS

OPN was accumulated in CD133+/CD44+ subgroup of HCC cells. Knocking down OPN significantly inhibited the sphere formation and stemness-related genes expression, and delayed tumor initiation of CD133+/CD44+ subgroup of HCC cells. Employing MedIP-sequencing, dot blot and iTRAQ analyses of CD133+/CD44+ SCR and CD133+/CD44+ shOPN cells, we found that OPN knockdown leaded to reduction in DNA methylation with particular enrichment in CGI. Meanwhile, DNA (cytosine-5)-methyltransferase 1 (DNMT1), the main methylation maintainer, was downregulated via proteomics analysis, which mediated OPN altering DNA methylation. Furthermore, DNMT1 upregulation could partially rescue the properties of CD133+/CD44+ shOPN cells. Both in vitro and in vivo assays showed that CD133+/CD44+ cells with high OPN levels were more sensitive to DNA methylation inhibitor, 5 Azacytidine (5 Aza). The above findings were validated in HCC primary cells, a more clinically relevant model.

CONCLUSIONS

OPN induces methylome reprogramming to enhance the stemness of CD133+/CD44+ subgroup and provides the therapeutic benefits to DNMT1 targeting treatment in HCC.

New role of osteopontin in DNA repair and impact on human glioblastoma radiosensitivity

Glioblastoma (GBM) represents the most aggressive and common solid human brain tumor. We have recently demonstrated the importance of osteopontin (OPN) in the acquisition/maintenance of stemness characters and tumorigenicity of glioma initiating cells. Consultation of publicly available TCGA database indicated that high OPN expression correlated with poor survival in GBM patients. In this study, we explored the role of OPN in GBM radioresistance using an OPN-depletion strategy in U87-MG, U87-MG vIII and U251-MG human GBM cell lines. Clonogenic experiments showed that OPN-depleted GBM cells were sensitized to irradiation. In comet assays, these cells displayed higher amounts of unrepaired DNA fragments post-irradiation when compared to control. We next evaluated the phosphorylation of key markers of DNA double-strand break repair pathway. Activating phosphorylation of H2AX, ATM and 53BP1 was significantly decreased in OPN-deficient cells. The addition of recombinant OPN prior to irradiation rescued phospho-H2AX foci formation thus establishing a new link between DNA repair and OPN expression in GBM cells. Finally, OPN knockdown improved mice survival and induced a significant reduction of heterotopic human GBM xenograft when combined with radiotherapy. This study reveals a new function of OPN in DNA damage repair process post-irradiation thus further confirming its major role in GBM aggressive disease.

lncRNAPCAT29 inhibits pulmonary fibrosis via the TGF‑β1‑regulated RASAL1/ERK1/2 signal pathway

Pulmonary fibrosis is a severe respiratory disease characterized by the aggregation of extracellular matrix components and inflammation‑associated injury. Studies have suggested that long non‑coding RNAs (lncRNA) may serve a role in the pathophysiological processes of pulmonary fibrosis. However, the potential molecular mechanisms involving the lncRNA, prostate cancer‑associated transcript 29 (lncRNAPCAT29) in the progression of pulmonary fibrosis are yet to be determined. In the present study, the role of lncRNAPCAT29 and the potential signaling mechanism in pulmonary fibrosis progression was investigated. Reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry revealed that the expression levels of lncRNAPCAT29 were downregulated within interstitial lung cells from mice with silica‑induced pulmonary fibrosis. Transfection with lncRNAPCAT29 was associated with upregulated expression of microRNA (miRNA)‑221 and downregulated expression of transforming growth factor‑β1 (TGF‑β1); reduced inflammation and fibrotic progression was also associated with lncRNAPCAT29 transfection. TGF‑β1 expression levels were inhibited within pulmonary fibroblasts due to lncRNAPCAT29 expression; NEDD4 binding protein 2 and Plexin‑A4 expression levels were also suppressed. Analysis of the potential mechanism underlying silica‑induced pulmonary fibrosis revealed that the expression levels of RAS protein activator like 1 (RASAL1) and extracellular signal‑regulated kinases 1/2 (ERK1/2) were suppressed due to lncRNAPCAT29 expression. The results of the present study demonstrated that lncRNAPCAT29 induced miRNA‑221 upregulation and TGF‑β1 downregulation. These observations were associated with reduced inflammation and progression of silica‑induced pulmonary fibrosis via the TGF‑β1‑regulated RASAL1/ERK1/2 signaling pathway, which may serve as a potential target for the treatment of pulmonary fibrosis.

Osteopontin b and c Splice isoforms in Leukemias and Solid Tumors: Angiogenesis Alongside Chemoresistance

Osteopontin (OPN) is a glycoprotein involved in regulation of various influences on tumor progression, such as cellular proliferation, apoptosis, angiogenesis, and metastasis. Vascular endothelial growth factor (VEGF) is a secreted molecule supporting angiogenesis in various cancers through activation of the PI3K/AKT/ERK1/2 pathway. OPN and VEGF have a number of isoforms with various activities. In spite of the well-defined association between OPN and VEGF isoform expression and cure rate for solid tumors, there is a scarcity of information as to any association in leukemia. Based on the critical role of OPN in cell survival, it seems reasonable to hypothesize that OPN and VEGF isoform expression levels may impact on chemoresistance and relapse in leukemia the same as in solid tumors. Hence, the aim of our review was to explain relationships between OPN and VEGF isoforms and angiogenesis and related pathways in chemoresistance of leukemia and solid tumors. Our findings demonstrated that OPNb and OPNc alongside with VEGF isoforms and other gene pathways are involved in angiogenesis and also might promote chemoresistance and even recurrence in leukemia and solid tumors. To sum up, targeting OPN isoforms, particularly b and c, might be a novel therapeutic strategy for the treatment of leukemia as well as solid tumors.

The role of osteopontin in the progression of solid organ tumour

Osteopontin (OPN) is a bone sialoprotein involved in osteoclast attachment to mineralised bone matrix, as well as being a bone matrix protein, OPN is also a versatile protein that acts on various receptors which are associated with different signalling pathways implicated in cancer. OPN mediates various biological events involving the immune system and the vascular system; the protein plays a role in processes such as immune response, cell adhesion and migration, and tumorigenesis. This review discusses the potential role of OPN in tumour cell proliferation, angiogenesis and metastasis, as well as the molecular mechanisms involved in these processes in different cancers, including brain, lung, kidney, liver, bladder, breast, oesophageal, gastric, colon, pancreatic, prostate and ovarian cancers. The understanding of OPN’s role in tumour development and progression could potentially influence cancer therapy and contribute to the development of novel anti-tumour treatments.

C-C chemokine receptor type 1 mediates osteopontin-promoted metastasis in hepatocellular carcinoma

In the hepatocellular carcinoma (HCC) microenvironment, chemokine receptors play a critical role in tumorigenesis and metastasis. Our previous studies have found that osteopontin (OPN) is a promoter for HCC metastasis. However, the role of chemokine receptors in OPN-induced HCC metastasis remains unclear. In this study, we demonstrate that OPN is dramatically elevated in HCC tissues with metastasis and that high expression of OPN correlates with poorer overall survival and higher recurrence rate. OPN upregulates chemokine receptor expression, migration, invasion and pulmonary metastasis in HCC. We find that C-C chemokine receptor type 1 (CCR1) and C-X-C chemokine receptor type 6 (CXCR6) are the most upregulated chemokine receptors induced by OPN. CCR1 knockdown results in reduction of migration, invasion and pulmonary metastasis induced by OPN in vitro and in vivo, whereas CXCR6 knockdown does not reverse OPN-promoted migration and invasion. Moreover, OPN upregulates the expression of CCR1 through activating phosphoinositide 3-kinase (PI3K)/AKT and hypoxia-inducible factor 1α (HIF-1α) in HCC cells. Furthermore, blockade of OPN-CCR1 axis with CCR1 antagonist significantly restrains the promoting effects of OPN on HCC progression and metastasis. In human HCC tissues, OPN expression shows significantly positive correlation with CCR1 expression, and the patients with high levels of both OPN and CCR1 have the most dismal prognosis. Collectively, our results indicate that the OPN-CCR1 axis in HCC is important for accelerating tumor metastasis and that CCR1 is a potential therapeutic target for controlling metastasis in HCC patients with high OPN.

Metalloproteinase meprin α regulates migration and invasion of human hepatocarcinoma cells and is a mediator of the oncoprotein Reptin

Hepatocellular carcinoma is associated with a high rate of intra-hepatic invasion that carries a poor prognosis. Meprin alpha (Mep1A) is a secreted metalloproteinase with many substrates relevant to cancer invasion. We found that Mep1A was a target of Reptin, a protein that is oncogenic in HCC. We studied Mep1A regulation by Reptin, its role in HCC, and whether it mediates Reptin oncogenic effects.

MepA and Reptin expression was measured in human HCC by qRT-PCR and in cultured cells by PCR, western blot and enzymatic activity measurements. Cell growth was assessed by counting and MTS assay. Cell migration was measured in Boyden chambers and wound healing assays, and cell invasion in Boyden chambers.

Silencing Reptin decreased Mep1A expression and activity, without affecting meprin β. Mep1A, but not meprin β, was overexpressed in a series of 242 human HCC (2.04 fold, p < 0.0001), and a high expression correlated with a poor prognosis. Mep1A and Reptin expressions were positively correlated (r = 0.39, p < 0.0001). Silencing Mep1A had little effect on cell proliferation, but decreased cell migration and invasion of HuH7 and Hep3B cells. Conversely, overexpression of Mep1A or addition of recombinant Mep1A increased migration and invasion. Finally, overexpression of Mep1A restored a normal cell migration in cells where Reptin was depleted.

Mep1A is overexpressed in most HCC and induces HCC cell migration and invasion. Mep1A expression is regulated by Reptin, and Mep1A mediates Reptin-induced migration. Overall, we suggest that Mep1A may be a useful target in HCC.

Osteopontin promotes metastasis of intrahepatic cholangiocarcinoma through recruiting MAPK1 and mediating Ser675 phosphorylation of β-Catenin

The incidence and mortality of intrahepatic cholangiocarcinoma (ICC) are increasing worldwide in recent decades. Osteopontin (OPN) plays an important role in cancer metastasis, but its functional mechanism in ICC is not clear yet. In this study, we found that OPN level was elevated both in plasma and tumor tissues of ICC patients, which was closely related to a shorter overall survival (OS) and high probability of tumor relapse after curative resection. The gain- and loss-of-function studies determined that OPN could promote ICC growth and metastasis. OPN selectively interacted with β-Catenin and knockdown of β-Catenin abrogated the effects induced by OPN. OPN recruited MAPK1 and activated MEK-MAPK1 pathway to mediate the S675 phosphorylation of β-Catenin and nucleus accumulation, which induced the activation of Wnt signaling. Moreover, a significant correlation between OPN and β-Catenin was found in ICC tissues. OPN, β-Catenin, and their combination were independent prognostic indicator for ICC patients. In conclusion, OPN promotes ICC progression through recruiting MAPK1 and activating the Wnt/β-Catenin pathway and can serve as a novel prognostic marker and therapeutic target for ICC.

Improving miRNA Delivery by Optimizing miRNA Expression Cassettes in Diverse Virus Vectors

The RNA interference pathway is an evolutionary conserved post-transcriptional gene regulation mechanism that is exclusively triggered by double-stranded RNA inducers. RNAi-based methods and technologies have facilitated the discovery of many basic science findings and spurred the development of novel RNA therapeutics. Transient induction of RNAi via transfection of synthetic small interfering RNAs can trigger the selective knockdown of a target mRNA. For durable silencing of gene expression, either artificial short hairpin RNA or microRNA encoding transgene constructs were developed. These miRNAs are based on the molecules that induce the natural RNAi pathway in mammals and humans: the endogenously expressed miRNAs. Significant efforts focused on the construction and delivery of miRNA cassettes in order to solve basic biology questions or to design new therapy strategies. Several viral vectors have been developed, which are particularly useful for the delivery of miRNA expression cassettes to specific target cells. Each vector system has its own unique set of distinct properties. Thus, depending on the specific application, a particular vector may be most suitable. This field was previously reviewed for different viral vector systems, and now the recent progress in the field of miRNA-based gene-silencing approaches using lentiviral vectors is reported. The focus is on the unique properties and respective limitations of the available vector systems for miRNA delivery.

Osteopontin promotes epithelial-mesenchymal transition of hepatocellular carcinoma through regulating vimentin

Our previous studies have found that osteopontin (OPN) is a promoter for hepatocellular carcinoma (HCC) progression. However, the molecular mechanism by which OPN enhances HCC metastasis remains elusive. Epithelial-mesenchymal transition (EMT) of cancer cells plays a pivotal role in promoting metastatic process. In this study, we demonstrated that OPN promotes HCC metastasis by inducing an EMT-like, more aggressive cellular phenotype in vitro and in vivo. Furthermore, OPN was identified to interact with vimentin by reciprocal OPN and vimentin immunoprecipitation as well as co-immunofluorescence examination. By using deletion mutants, we found that the residues between 246 and 406 in vimentin are required for binding to OPN. Importantly, OPN significantly increased vimentin stability through inhibition of its protein degradation. Knockdown of vimentin neutralized the EMT induced by OPN both in vitro and in vivo. Moreover, a significant correlation between OPN and vimentin levels was found in clinical HCC specimens and their combination had a worse prognosis with shorter overall survival (OS) and time to recurrence (TTR). In multivariate analysis, OPN and their combination were demonstrated to be independent prognostic indicators for OS and TTR of HCC patients. Collectively, this study indicates that OPN can induce EMT of HCC cells through increasing vimentin stability, which provides more in-depth understanding about the molecular mechanisms of OPN in promoting HCC metastasis and opens tantalizing therapeutic possibilities in HCC.

CCN3 is a therapeutic target relating enhanced stemness and coagulation in hepatocellular carcinoma

The general prognosis of patients with hepatocellular carcinoma (HCC) remains extremely dismal, due to the high frequency of metastasis. Since 2003, our research group has explored the gene expression profiles of metastasized HCC tissue samples and identified a significant upregulation of CCN3. However, the role and precise pathological function of CCN3 remains elusive. We showed that CCN3 is associated with the poor prognosis of patients with HCC, the malignant phenotype of HCC, and vascular thrombosis. We further evaluated the negative roles of CCN3 in vitro and in vivo, and identified osteopontin (OPN), and coagulation factors tissue factor (TF) and thrombin as the leading genes downstream of CCN3, that are positively associated with HCC cell stemness. We demonstrated that overexpressed CCN3 in HCC cells leads to enhanced survival and increased number of pulmonary metastases in vivo. The elevated levels of OPN and TF were associated with signal activation of nuclear factor κB (NFκB) and extracellular signal-regulated kinases (ERK). Our findings suggest CCN3 is a potential therapeutic target that would affect the upregulation of OPN and coagulation factors, which would lead to an enhanced stemness and blood coagulation microenvironment in HCC tissue.

Pivotal roles of glycogen synthase-3 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, and represents the second most frequently cancer and third most common cause of death from cancer worldwide. At advanced stage, HCC is a highly aggressive tumor with a poor prognosis and with very limited response to common therapies. Therefore, there is still the need for new effective and well-tolerated therapeutic strategies. Molecular-targeted therapies hold promise for HCC treatment. One promising molecular target is the multifunctional serine/threonine kinase glycogen synthase kinase 3 (GSK-3). The roles of GSK-3β in HCC remain controversial, several studies suggested a possible role of GSK-3β as a tumor suppressor gene in HCC, whereas, other studies indicate that GSK-3β is a potential therapeutic target for this neoplasia. In this review, we will focus on the different roles that GSK-3 plays in HCC and its interaction with signaling pathways implicated in the pathogenesis of HCC, such as Insulin-like Growth Factor (IGF), Notch, Wnt/β-catenin, Hedgehog (HH), and TGF-β pathways. In addition, the pivotal roles of GSK3 in epithelial-mesenchymal transition (EMT), invasion and metastasis will be also discussed.

Osteopontin -- a promising biomarker for cancer therapy

Osteopontin (OPN), a multifunctional protein, has emerged as a potentially valuable biomarker for diagnosing and treating cancers. Recent research focuses on its involvement in tumor biology including the cell proliferation, survival, angiogenesis, invasion, and metastasis. Understanding the molecular mechanisms and pharmacological effects of OPN in cancer development could lead to new targets for improving cancer diagnosis and treatment. This review explains how the structurally conserved domains of OPN are associated with OPN signaling mediators and CD44, and how the conserved OPN domains determine biological functions. The authors have reviewed representative works of OPN expression in breast cancer and colorectal cancer to elucidate the relationship between OPN and cancer/tumor biology. It has also been shown that the prognostic sensitivity in non-small cell lung cancer, hepatocellular carcinoma, gastric cancer, and ovarian cancer improved compared to the individual marker when OPN was analyzed in conjunction with other markers. The therapeutic approaches based on OPN inhibitors are discussed to illustrate recent research progress. Previous clinical data has indicated that OPN has played a unique role in cancer development, but further investigation is required to understand the underlying mechanism. More clinical trials are also required to examine the applicability and efficacy of OPN inhibitors in cancer therapy.

Suppression of osteopontin inhibits chemically induced hepatic carcinogenesis by induction of apoptosis in mice

Previous clinical reports have found elevated osteopontin (OPN) levels in tumor tissues to be indicative of greater malignancy in human hepatocellular carcinoma (HCC). However, the role of OPN on carcinogenesis and its underlying mechanism remain unclear. In the present study, we investigated the oncogenic role of OPN in diethylnitrosamine (DEN)-induced hepatic carcinogenesis in mice. The overall incidence of hepatic tumors at 36 weeks was significantly lower in OPN knockout (KO) mice than in wild-type (WT) mice. Apoptosis was significantly enhanced in OPN KO mice, and was accompanied by the downregulation of epidermal growth factor receptor (EGFR). In the in vitro study, OPN suppression also led to lower mRNA and protein levels of EGFR associated with the downregulation of c-Jun in Hep3B and Huh7 human HCC cells lines, which resulted in increased apoptotic cell death in both cell lines. Moreover, a positive correlation was clearly identified between the expression of OPN and EGFR in human HCC tissues. These data demonstrate that the OPN deficiency reduced the incidence of chemically induced HCC by suppressing EGFR-mediated anti-apoptotic signaling. An important implication of our findings is that OPN positively contributes to hepatic carcinogenesis.

KIT over-expression by p55PIK-PI3K leads to Imatinib-resistance in patients with gastrointestinal stromal tumors

Imatinib is the first-line drug for gastrointestinal stromal tumors (GISTs), as mutated KIT is closely associated with the occurrence of GIST. However, Imatinib resistance (IMA-resistance) occurs inevitably in most GIST patients. Although the over-expression of KIT in GIST is one of the major factors contributing to IMA-resistance, the underlying mechanism is still unclear. In this study, we demonstrate that p55PIK, an isoform of phosphoinositide 3-kinase (PI3K), increases KIT expression, leading to IMA-resistance in GISTs by activating NF-κB signaling pathway. Furthermore, down-regulation of p55PIK significantly decreases KIT expression and re-sensitizes IMA-resistance-GIST cells to Imatinib in vitro and in vivo. Interestingly, the expression of both p55PIK and KIT proteins is significantly increased in tumor samples from IMA-resistance-GIST patients, suggesting that p55PIK up-regulation may be important for IMA-resistance in the clinical setting. Altogether, our data provide evidence that p55PIK-PI3K signaling can contribute to IMA-resistance in GIST by increasing KIT expression. Moreover, p55PIK may be a novel potential drug target for treating tumors that develop IMA-resistance.

Osteopontin induces autophagy to promote chemo-resistance in human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a major health burden worldwide for its high incidence and mortality. Osteopontin (OPN) is a chemokine-like, matricellular phosphoglycoprotein whose expression is elevated in various types of cancer including HCC. OPN has been shown to be involved in tumorigenesis, chemo-resistance, metastasis and sustaining stem-like properties of cancer cells. Autophagy is a cellular process by which cytoplasmic components are degraded and recycled for maintaining cellular homeostasis. There is increasing evidence supports that autophagy plays a critical role for stem-like properties and chemo-resistance of cancer cells. However, the relationship between OPN and autophagy in maintaining cancer stem-like properties and chemo-resistance is yet to be clarified. Herein, we found that secreted OPN induced autophagy via binding with its receptor integrin αvβ3 and sustaining FoxO3a stability. OPN-elicited autophagy could promote cancer cell survival and resistance to chemotherapy drugs, as well as stem-like properties. Our findings indicated that OPN was capable of promoting chemo-resistance of HCCs via autophagy, which might provide a new strategy for the treatment of HCC.

Upregulation of FAM83D affects the proliferation and invasion of hepatocellular carcinoma

The identification of potential oncogenes plays an important role in finding novel therapeutic targets for many cancers, including hepatocellular carcinoma (HCC), which is one of the most common cancers worldwide. In our previous research, using microarray technology, we found that FAM83D was overexpressed in HCCs. However, whether the overexpression of FAM83D contributes to hepatocarcinogenesis remains unclear. In this study, we found that FAM83D was significantly upregulated in 76.6% (167 of 218) of the HCC specimens at the mRNA level and in 69.44% (50 of 72) of the HCC specimens at the protein level compared with adjacent non-cancerous liver specimens, as indicated by RT-PCR and immunohistochemical staining, respectively. The FAM83DmRNA expression level was positively correlated with the level of alpha-fetoprotein (AFP) (≥100 ng/ml), the clinical TNM stage, the presence of a portal vein tumor thrombus (PVTT), disease-free survival (DFS) and the overall survival (OS) time of the HCC patients (P < 0.05). Knocking down FAM83D significantly promoted the growth of Huh7 and HepG2 cells, as demonstrated in an RNA interference assay. Moreover, the DNA methylation status of the FAM83D promoter was significantly reduced in the HCC specimens with overexpression of FAM83D gene. Our data suggest that the upregulation of FAM83D, a potential oncotarget gene, may be triggered by epigenetic events and can contribute to hepatocarcinogenesis.

Role of Osteopontin in Liver Diseases

Osteopontin (OPN), a multifunctional protein, is involved in numerous pathological conditions including inflammation, immunity, angiogenesis, fibrogenesis and carcinogenesis in various tissues. Extensive studies have elucidated the critical role of OPN in cell signaling such as regulation of cell proliferation, migration, inflammation, fibrosis and tumor progression. In the liver, OPN interacts with integrins, CD44, vimentin and MyD88 signaling, thereby induces infiltration, migration, invasion and metastasis of cells. OPN is highlighted as a chemoattractant for macrophages and neutrophils during injury in inflammatory liver diseases. OPN activates hepatic stellate cells (HSCs) to exert an enhancer in fibrogenesis. The role of OPN in hepatocellular carcinoma (HCC) has also generated significant interests, especially with regards to its role as a diagnostic and prognostic factor. Interestingly, OPN acts an opposing role in liver repair under different pathological conditions. This review summarizes the current understanding of OPN in liver diseases. Further understanding of the pathophysiological role of OPN in cellular interactions and molecular mechanisms associated with hepatic inflammation, fibrosis and cancer may contribute to the development of novel strategies for clinical diagnosis, monitoring and therapy of liver diseases.

Osteopontin Fragments with Intact Thrombin-Sensitive Site Circulate in Cervical Cancer Patients

We investigated whether circulating osteopontin (OPN) could be used as a biomarker for cervical cancer. We employed a monoclonal antibody (mAb 659) specific for the unique and intact thrombin-sensitive site in OPN using an inhibition ELISA. We found significantly higher levels of OPN in 33 cervical cancer patients in both the plasma (mean +/- SD, 612 +/- 106 ng/mL) and serum (424 +/- 121 ng/mL) compared to healthy subjects [409 +/- 56 ng/mL, from 31 plasma samples (P < 0.0001), and 314 +/- 98 ng/mL, from 32 serum samples (P = 0.0002), respectively]. Similar results were obtained when the plasma from a bigger group (147 individuals) of cervical cancer patients (560 +/- 211 ng/mL) were compared with the same plasma samples of the healthy individuals (P = 0.0014). More significantly, the OPN level was highest in stage III-IV disease (614 +/- 210 ng/mL, from 52 individuals; P = 0.0001) and least and non-discriminatory in stage I (473 +/- 110 ng/mL, from 40 individuals; P = 0.5318). No such discrimination was found when a mAb of a different specificity (mAb 446) was used in a similar inhibition ELISA to compare the two groups in the first study; a commercial capture ELISA also failed. The possibility that the target epitope recognized by the antibody probe in these assays was absent from the circulating OPN due to protein truncation was supported by gel fractionation of the OPN found in patients' plasma: 60-64 kDa fragments were found instead of the presumably full-length OPN (68 kDa) seen in healthy people. How these fragments are generated and what possible role they play in cancer biology remain interesting questions.