Loss of RUNX3 increases osteopontin expression and promotes cell migration in gastric cancer

RUNX Proteins as Epigenetic Modulators in Cancer

RUNX proteins are highly conserved in metazoans and perform critical functions during development. Dysregulation of RUNX proteins through various molecular mechanisms facilitates the development and progression of various cancers, where different RUNX proteins show tumor type-specific functions and regulate different aspects of tumorigenesis by cross-talking with different signaling pathways such as Wnt, TGF-β, and Hippo. Molecularly, they could serve as transcription factors (TFs) to activate their direct target genes or interact with many other TFs to modulate chromatin architecture globally. Here, we review the current knowledge on the functions and regulations of RUNX proteins in different cancer types and highlight their potential role as epigenetic modulators in cancer.

Ziyin Huatan Recipe, a Chinese herbal compound, inhibits migration and invasion of gastric cancer by upregulating RUNX3 expression

OBJECTIVES

Ziyin Huatan Recipe (ZYHT), a traditional Chinese medicine comprised of Lilii Bulbus, Pinelliae Rhizoma, and Hedyotis Diffusa, has shown promise in treating gastric cancer (GC). However, its potential mechanism has not yet been clearly addressed. This study aimed to predict targets and molecular mechanisms of ZYHT in treating GC by network pharmacology analysis and to explore the role of ZYHT in GC both in vitro and in vivo.

METHODS

Targets and molecular mechanisms of ZYHT were predicted via network pharmacology analysis. The effects of ZYHT on the expression of metastasis-associated targets were further validated by Western blot and quantitative real-time polymerase chain reaction. To explore the specific molecular mechanisms of the effects of ZYHT on migration and invasion, the runt-related transcription factor 3 (RUNX3) gene was knocked out by clustered regularly interspaced short palindromic repeats/Cas9, and lentiviral vectors were transfected into SGC-7901 cells. Then lung metastasis model of GC in nude mice was established to explore the anti-metastasis effect of ZYHT. Western blot and immunohistochemistry were used to explore the impact of ZYHT on the expression of metastasis-related proteins with or without RUNX3 gene.

RESULTS

The network pharmacology analysis showed that ZYHT might inhibit focal adhesion, migration, invasion and metastasis of GC. ZYHT inhibited the proliferation, migration and invasion of GC cells in vitro via regulating the expression of metastasis-associated targets. Knocking out RUNX3 almost completely reversed the cell phenotypes (migration and invasion) and protein expression levels elicited by ZYHT. In vivo studies showed that ZYHT inhibited the metastasis of GC cells to the lung and prolonged the survival time of the nude mice. Knocking out RUNX3 partly reversed the metastasis of GC cells to the lung and the protein expression levels elicited by ZYHT.

CONCLUSION

ZYHT can effectively inhibit the invasion and migration of GC in vitro and in vivo, and its molecular mechanism may relate to the upregulation of RUNX3 expression.

Implications of protein ubiquitination modulated by lncRNAs in gastrointestinal cancers

Long non-coding RNAs (lncRNAs) are a class of RNA transcripts longer than 200 nucleotides and mostly cannot be translated into proteins. Next-generation transcriptome sequencing of various cell types has enabled the annotation of tens of thousands of lncRNAs in human genome. Varying levels of evidence supports the implications of lncRNAs in the onset and progression of cancers. Ubiquitin is an evolutionarily conserved protein and could post-translationally mark a number of proteins. The most important proteolytic role of ubiquitination is degradation of substrate proteins by the 26S proteasome. Compiling evidences demonstrated that lncRNAs are involved in the accurate execution of protein stability programs via the ubiquitin-proteasome system. In the current review, we systematically summarize the detailed mechanisms how lncRNAs modulate ubiquitination of target proteins, regulate cancerous signaling pathways and control tumorigenesis of gastrointestinal cancers. Although there are still considerable studies on unraveling the complicated interactions between lncRNAs and proteins, we believe that lncRNAs are promising but challenging molecules which may strongly facilitate precision cancer therapeutics in the future.

BET inhibitor suppresses melanoma progression via the noncanonical NF-κB/SPP1 pathway

Background: Bromodomain and extra-terminal domain (BET) inhibitors have shown profound efficacy against hematologic malignancies and solid tumors in preclinical studies. However, the underlying molecular mechanism in melanoma is not well understood. Here we identified secreted phosphoprotein 1 (SPP1) as a melanoma driver and a crucial target of BET inhibitors in melanoma. Methods: Bioinformatics analysis and meta-analysis were used to evaluate the SPP1 expression in normal tissues, primary melanoma, and metastatic melanoma. Real-time PCR (RT-PCR) and Western blotting were employed to quantify SPP1 expression in melanoma cells and tissues. Cell proliferation, wound healing, and Transwell assays were carried out to evaluate the effects of SPP1 and BET inhibitors in melanoma cells in vitro. A xenograft mouse model was used to investigate the effect of SPP1 and BET inhibitors on melanoma in vivo. Chromatin immunoprecipitation (ChIP) assay was performed to evaluate the regulatory mechanism of BET inhibitors on SPP1. Results: SPP1 was identified as a melanoma driver by bioinformatics analysis, and meta-analysis determined it to be a diagnostic and prognostic biomarker for melanoma. SPP1 overexpression was associated with poor melanoma prognosis, and silencing SPP1 suppressed melanoma cell proliferation, migration, and invasion. Through a pilot drug screen, we identified BET inhibitors as ideal therapeutic agents that suppressed SPP1 expression. Also, SPP1 overexpression could partially reverse the suppressive effect of BET inhibitors on melanoma. We further demonstrated that bromodomain-containing 4 (BRD4) regulated SPP1 expression. Notably, BRD4 did not bind directly to the SPP1 promoter but regulated SPP1 expression through NFKB2. Silencing of NFKB2 resembled the phenotype of BET inhibitors treatment and SPP1 silencing in melanoma. Conclusion: Our findings highlight SPP1 as an essential target of BET inhibitors and provide a novel mechanism by which BET inhibitors suppress melanoma progression via the noncanonical NF-κB/SPP1 pathway.

Squalene synthase promotes the invasion of lung cancer cells via the osteopontin/ERK pathway

Cholesterol is the major component of lipid rafts. Squalene synthase (SQS) is a cholesterol biosynthase that functions in cholesterol biosynthesis, modulates the formation of lipids rafts and promotes lung cancer metastasis. In this study, we investigated the lipid raft-associated pathway of SQS in lung cancer. Gene expression microarray data revealed the upregulation of secreted phosphoprotein 1 (SPP1; also known as osteopontin, OPN) in CL1-0/SQS-overexpressing cells. Knockdown of OPN in SQS-overexpressing cells inhibits their migration and invasion, whereas an OPN treatment rescues the migration and invasion of SQS knockdown cells. High OPN expression is associated with lymph node status, advanced stage and poor prognosis in patients with lung cancer. Moreover, patients with high SQS expression and high OPN expression show poor survival compared with patients with low SQS expression and low OPN expression. SQS induces the phosphorylation of Src and ERK1/2 via OPN, resulting in increased expression of MMP1 and subsequent metastasis of lung cancer cells. Based on our findings, SQS expression increases the expression of OPN and phosphorylation of Src through cholesterol synthesis to modulate the formation of lipid rafts. SQS may represent a therapeutic strategy for lung cancer.

Emerging role of RUNX3 in the regulation of tumor microenvironment

A number of genes have been therapeutically targeted to relieve cancer, but cancer relapse is still a growing issue. The concept that the surrounding tumor environment is critical for the progression of cancer may foster an answer to the issue of cancer malignancy. Runt domain transcription factors (RUNX1, 2, and 3) are evolutionarily conserved and have been intensively studied for their roles in normal development and pathological conditions. During tumor growth, a hypoxic microenvironment and infiltration of the tumor by immune cells are common phenomena. In this review, we briefly introduce the consequences of hypoxia and immune cell infiltration into the tumor microenvironment with a focus on RUNX3 as a critical regulator. Furthermore, based on our current knowledge of the functional role of RUNX3 in hypoxia and immune cell maintenance, a probable therapeutic intervention is suggested for the effective management of tumor growth and malignancy. [BMB Reports 2018; 51(4): 174-181].

HOTAIR induces the ubiquitination of Runx3 by interacting with Mex3b and enhances the invasion of gastric cancer cells

BACKGROUND

Long non-coding RNAs (LncRNAs) exert their functions mainly by binding to their corresponding proteins. Runt-related transcription factor 3 (Runx3) is an important transcription factor that functions as a tumor suppressor in gastric cancer. Whether there is an interplay between LncRNAs and Runx3 remains unclear.

METHODS

RPISeq was applied to screen the LncRNAs that potentially bind to Runx3. The interaction between LncRNA HOX antisense intergenic RNA (HOTAIR) and Runx3 was validated by RNA Immunoprecipitation and RNA pull-down assays. The role of Mex3b in the ubiquitination of Runx3 induced by HOTAIR was assessed by immunoprecipitation. Pearson's correlation between HOTAIR mRNA expression and Runx3 protein expression was analyzed. Cell migration and invasion were explored by transwell assays.

RESULTS

We found that HOTAIR was bound to Runx3 protein and identified the fragment of HOTAIR spanning 1951-2100 bp as the specific binding site. In addition, mex-3 RNA binding family member B (Mex3b) was an E3 ligase involved in HOTAIR-induced ubiquitous degradation of Runx3. Silencing the expression of HOTAIR or Mex3b attenuated the degradation of Runx3. In human gastric cancer tissues, HOTAIR was negatively associated with the expression level of Runx3 protein (Pearson coefficient - 0.501, p = 0.025). Inhibition of HOTAIR significantly suppressed gastric cancer cell migration and invasion through upregulating claudin1, which could be reversed by co-deficiency of Runx3.

CONCLUSIONS

These results uncovered the novel interaction between HOTAIR and Runx3, and provided potential therapeutic targets on the metastasis of gastric cancer.

Multi-omics analysis identifies pathways and genes involved in diffuse-type gastric carcinogenesis induced by E-cadherin, p53, and Smad4 loss in mice

The molecular mechanisms underlying the pathogenesis of diffuse-type gastric cancer (DGC) have not been adequately explored due to a scarcity of appropriate animal models. A recently developed tool well suited for this line of investigation is the Pdx-1-Cre;Cdh1^F/+ ;Trp53^F/F ;Smad4^F/F (pC^he PS) mouse model that spontaneously develops metastatic DGC showing nearly complete E-cadherin loss. Here, we performed a proteogenomic analysis to uncover the molecular changes induced by the concurrent targeting of E-cadherin, p53, and Smad4 loss. The gene expression profiles of mouse DGCs and in vivo gastric phenotypes from various combinations of gene knockout demonstrated that these mutations collaborate to activate cancer-associated pathways to generate aggressive DGC. Of note, WNT-mediated epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM)-cytokine receptor interactions were prominently featured. In particular, the WNT target gene osteopontin (OPN) that functions as an ECM cytokine is highly upregulated. In validation experiments, OPN contributed to DGC stemness by promoting cancer stem cell (CSC) survival and chemoresistance. It was further found that Bcl-xL acts as a targetable downstream effector of OPN in DGC CSC survival. In addition, Zeb2 and thymosin-β4 (Tβ4) were identified as prime candidates as suppressors of E-cadherin expression from the remaining Cdh1 allele during DGC development. Specifically, Tβ4 suppressed E-cadherin expression and anoikis while promoting cancer cell growth and migration. Collectively, these proteogenomic analyses broaden and deepen our understanding of the contribution of key driver mutations in the stepwise carcinogenesis of DGC through novel effectors, namely OPN and Tβ4.

Clinicopathological and prognostic significance of the RUNX3 expression in gastric cancer: a systematic review and meta-analysis

BACKGROUND

The relationship between expression of runt related transcription factor 3 (RUNX3) and clinicopathological parameters of the patients with gastric cancer (GC) is controversial.

METHODS

The studies were retrieved from those already published essay in PubMed, EMBASE, Wan Fang, CNKI (China National Knowledge Infrastructure), the Cochrane Library and Google Scholar. All statistical tests in this meta-analysis were performed using Stata 10.0 software (Stata Corp, College Station, TX). A P value less than 0.05 was considered statistically significant.

RESULTS

A total of nine studies involving 796 patients were included in final meta-analysis. The pooled data showed that expression of RUNX3 was significant correlated with tumor's differentiation (OR = 0.387; 95%CI: 0.237-0.633; P = 0.000), depth of invasion (OR = 0.443; 95%CI: 0.273-0.717; P = 0.001), lymph node metastasis (OR = 0.394; 95%CI: 0.259-0.598; P = 0.000), distant metastasis (OR = 0.403; 95%CI: 0.213-0.764; P = 0.005) and TNM stage (OR = 0.461; 95%CI, 0.322-0.659; P = 0.000) in GC. Expression of RUNX3 was significant correlated with good overall survival (OS) [1-year OS (OR = 2.735; 95%CI: 1.966-3.806; P = 0.000), 3-year OS (OR = 4.782; 95%CI: 3.634-6.292; P = 0.000), 5-year OS (OR = 5.191; 95%CI: 3.775-7.138; P = 0.000]. However, RUNX3 was not correlated with gender (OR = 1.409; 95%CI: 0.986-2.014; P = 0.060).

CONCLUSION

RUNX3 expression correlates with tumor's differentiation, depth of invasion, lymph node metastasis, distant metastasis, TNM stage and OS of GC patients.

Clinical and in vitro analysis of Osteopontin as a prognostic indicator and unveil its potential downstream targets in bladder cancer

Osteopontin (OPN) plays an important role in cancer progression, however its prognostic significance and its downstream factors are largely elusive. In this study, we have shown that expression of OPN was significantly higher in bladder cancer specimens with higher T-stage or tumor grades. In addition, a high level of OPN was significantly associated with poorer survival in two independent bladder cancer patient cohorts totaling 389 bladder cancer patients with available survival data. We further identified Matrix metallopeptidase 9 (MMP9) and S100 calcium-binding protein A8 (S100A8) were both downstream factors for OPN in bladder cancer specimens and bladder cancer cell lines. Expression of OPN was significantly positively associated with that of MMP9 and S100A8, while overexpression of OPN resulted in upregulation of MMP9 and S100A8, and knockdown of OPN showed consistent downregulation of MMP9 and S100A8 expression levels. Importantly, expression levels of both MMP9 and S100A8 were significantly associated with higher T-stage, higher tumor grade and a shorter survival time in the bladder cancer patients. Interestingly, OPN expression only predicted survival in MMP9-high, but not MMP9-low subgroups, and in S100A8-low but not S100A8-high subgroups. Our results suggest that OPN, MMP9 and S100A8 all play a significant role in bladder cancer progression and are potential prognostic markers and therapeutic targets in bladder cancer. The mechanistic link between these three genes and bladder cancer progression warrants further investigation.

RUNX3 plays a tumor suppressor role by inhibiting cell migration, invasion and angiogenesis in oral squamous cell carcinoma

Although aberrant expression of Runt-related transcription factor 3 (RUNX3) contributes to tumor progression and metastasis in a number of carcinomas, the status of RUNX3 and its correlation with prognosis in oral squamous cell carcinomas (OSCC) are still controversial. The aim of present study was to investigate the function of RUNX3 in OSCC and the underlying molecular mechanisms. Tissue microarray (TMA) consisting of 232 OSCC specimens was used to detect the expression of RUNX3 by immunohistochemistry method. The effects of RUNX3 restoration on OSCC cell migration and invasion were determined by wound-healing assay, migration and Matrigel cell invasion assays. The antiangiogenic role of RUNX3 was analyzed by testing proliferation and tube formation of human umbilical vascular endothelial cells (HUVECs) cultured with conditioned medium from RUNX3 transfected OSCC cell lines. The activities of MMP-9 and VEGF in RUNX3 transfected OSCC cell lines were examined by western blot and Elisa methods. RUNX3 expression was reduced in OSCC specimens and significantly associated with tumor size (P=0.002), lymph node statue (P=0.0036) and clinical stage (P=0.0001). Negative expression of RUNX3 correlated with worse 5-year overall and disease-specific survival rates (P=0.0348 and P=0.0301, respectively). Furthermore, we found that RUNX3 restoration suppressed cell migration and invasion through downregulating MMP-9 expression and secretion, and exerted antiangiogenic capability by inhibiting VEGF activity in HN6 and Cal27 cells. These findings suggested that RUNX3 played a tumor suppressor role in OSCC by inhibiting cell migration, invasion and angiogenesis, supporting that it could be a potential therapeutic target for OSCC.

Runx3 inhibits melanoma cell migration through regulation of cell shape change

The transcription factor Runx3 is a known tumor suppressor gene, and its expression is frequently lost in melanoma. However, the potential contribution of the loss of Runx3 expression to melanoma development and progression remains unclear. In this in vitro study, we demonstrated that ectopic Runx3 re-expression in B16-F10 melanoma cells changed the cell shape from elongated and branched to spread and unbranched, which enhanced stress fiber formation, increased the number of mature and fibrillar focal adhesions, and up-regulated fibronectin expression. In association with the cell shape change, the Runx3 re-expression in B16-F10 melanoma cells inhibited cell migration. Moreover, the phenotype of the Runx3 induced cell shape change was partially resembled when the melanoma cells were cultured on a fibronectin-coated coverslip, suggesting that fibronectin may mediate the Runx3 induced cell shape change of the melanoma cells. Taken together, our findings suggest that Runx3 may regulate cell shape to inhibit melanoma cell migration partly through enhancing stress fiber formation and ECM protein production. Our present study provides further evidence for the idea that cell shape change is potentially correlated with melanoma development and progression.

The Emerging Roles of RUNX Transcription Factors in Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is an evolutionary conserved morphogenetic program necessary for the shaping of the body plan during development. It is guided precisely by growth factor signaling and a dedicated network of specialised transcription factors. These are supported by other transcription factor families serving auxiliary functions during EMT, beyond their general roles as effectors of major signaling pathways. EMT transiently induces in epithelial cells mesenchymal properties, such as the loss of cell-cell adhesion and a gain in cell motility. Together, these newly acquired properties enable their migration to distant sites where they eventually give rise to adult epithelia. However, it is now recognized that EMT contributes to the pathogenesis of several human diseases, notably in tissue fibrosis and cancer metastasis. The RUNX family of transcription factors are important players in cell fate determination during development, where their spatio-temporal expression often overlaps with the occurrence of EMT. Furthermore, the dysregulation of RUNX expression and functions are increasingly linked to the aberrant induction of EMT in cancer. The present chapter reviews the current knowledge of this emerging field and the common themes of RUNX involvement during EMT, with the intention of fostering future research.

Role of osteopontin in lung cancer evolution and heterogeneity

Patients with lung cancer still have high mortality, recurrence rate after adjuvant treatment, and poor five-year survival rates, despite of advances in multidisciplinary anti-cancer therapies, e.g. chemotherapy, radiotherapy and targeted therapies, It depends upon the presence of intratumoral heterogeneity and complexity of lung cancer. There is growing evidence to suggest that osteopontin (OPN) may play a critical role in tumor progression and metastasis. The present review briefly describes the structure and molecular biology of OPN, highlights the role of OPN in the development and metastasis of lung cancer, and summarizes potential mechanisms of OPN heterogeneity in tumor to underline some of these inconsistencies. The article will emphasize the importance to understand the role of OPN in cancer evolution and heterogeneity and explore the potential of OPN as a therapeutic target.

Osteopontin expression is correlated with differentiation and good prognosis in medullary thyroid carcinoma

BACKGROUND

Osteopontin (OPN) or secreted phosphoprotein 1 (SPP1) is a matricellular glycoprotein whose expression is elevated in various types of cancer and has been shown to be involved in tumourigenesis and metastasis in many malignancies, including follicular cell-derived thyroid carcinomas. Its role in C-cell-derived thyroid lesions and tumours remains to be established.

OBJECTIVE

The objective of this study is to clarify the role of OPN expression in the development of medullary thyroid carcinoma (MTC).

METHODS

OPN expression was analysed in a series of 116 MTCs by immunohistochemistry and by qPCR mRNA quantification of the 3 OPN isoforms (OPNa, OPNb and OPNc) in six cases from which fresh frozen tissue was available. Statistical tests were used to evaluate the relationship of OPN expression and the clinicopathological and molecular characteristics of patients and tumours.

RESULTS

OPN expression was detected in 91 of 116 (78.4%) of the MTC. We also observed high OPN expression in C-cell hyperplasia as well as in C-cells scattered in the thyroid parenchyma adjacent to the tumours. OPN expression was significantly associated with smaller tumour size, PTEN nuclear expression and RAS status, and suggestively associated with non-invasive tumours. OPNa isoform was expressed significantly at higher levels in tumours than in non-tumour samples. OPNb and OPNc presented similar levels of expression in all samples. Furthermore, OPNa isoform overexpression was significantly associated with reduced growth and viability in the MTC-derived cell line (TT).

CONCLUSION

The expression of OPN in normal C-cells and C-cell hyperplasia suggests that OPN is a differentiation marker of C-cells, rather than a marker of biological aggressiveness in this setting. At variance with other cancers, OPN expression is associated with good prognostic features in MTC.

The emerging role of RUNX3 in cancer metastasis (Review)

Metastasis remains the major driver of mortality in patients with cancer. The multistep metastatic process starts with the dissemination of tumor cells from a primary site and leading to secondary tumor development in an anatomically distant location. Although significant progress has been made in understanding the molecular characteristics of metastasis, many questions remain regarding the intracellular mechanisms governing transition through the various metastatic stages. The runt-related transcription factor 3 (RUNX3) is a downstream effector of the transforming growth factor-β (TGF-β) signaling pathway, and has critical roles in the regulation of cell death by apoptosis, and in angiogenesis, epithelial-to-mesenchymal transition (EMT), cell migration and invasion. RUNX3 functions as a bona fide initiator of carcinogenesis by linking the Wnt oncogenic and TGF-β tumor suppressive pathways. RUNX3 is frequently inactivated in human cancer cell lines and cancer samples by hemizygous deletion of the Runx3 gene, hypermethylation of the Runx3 promoter, or cytoplasmic sequestration of RUNX3 protein. Inactivation of RUNX3 makes it a putative tumor suppressor in human neoplasia. In the present review, we summarize the proposed roles of RUNX3 in metastasis and, when applicable, highlight the mechanism by which they function.

miR-130a acts as a potential diagnostic biomarker and promotes gastric cancer migration, invasion and proliferation by targeting RUNX3

MicroRNAs (miRNAs) are abnormally expressed in various types of cancer. miR-130a expression and function in gastric cancer has yet to be elucidated. The aim of the present study was to identify the miR-130a expression and function in gastric cancer. miR-130a expression was examined in gastric cancer cell lines and tissues by RT-qPCR. The diagnostic and prognostic significance of miR-130a in gastric cancer was analyzed by receiver-operating characteristic (ROC) curve and Kaplan-Meier analysis. miR130a expression was identified and the diagnostic significance in the serum of gastric cancer patients and healthy controls was analyzed using RT-qPCR and ROC curves, respectively. A target gene for miR-130a was identified using luciferase reporter assays, and gastric cancer tumorigenesis ability was examined by 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays. The results showed that miR‑130a was upregulated in gastric cancer. The low-miR-130a group had significantly improved overall survival compared to the high-miR-130a group. Furthermore, the expression of miR‑130a in plasma in gastric cancer patients was upregulated and diagnostic value for gastric cancer of miR-130a is more effective than the tumor markers carcinoembryonic antigen (CEA) and CA-199. miR-130a directly targeted runt‑related transcription factor 3 (RUNX3) and promoted gastric cancer tumorigenesis by targeting RUNX3. miR-130a may therefore be a useful marker for the diagnosis and prognosis of gastric cancer. Additionally, miR-130a was identified as an oncogene that promotes gastric cancer tumorigenesis by targeting RUNX3.

MicroRNA-125b and chemokine CCL4 expression are associated with calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a progressive pathological condition with no effective pharmacological therapy. To identify novel molecular pathways as potential targets for pharmacotherapy, we studied microRNA (miRNA) profiles of heavily stenotic aortic valves (AS). One of the most upregulated miRNAs in AS valves compared to control valves was miR-125b (1.4-fold; P < 0.05). To identify CAVD-related changes in gene expression, DNA microarray analysis was performed, including an intermediate fibro(sclero)tic stage of the disease. This revealed changes especially in genes related to inflammation and immune response, including chemokine (C-C motif) ligand 3 (CCL3) and 4 (CCL4). CCL3 mRNA level was increased 3.9-fold (P < 0.05) when AS valves were compared to control valves, and a 2.5-fold increase (P < 0.05) in CCL4 gene expression was observed when fibro(sclero)tic valves were compared to control valves. Both CCL3 and CCL4 localized to macrophages by immunofluorescence. To identify chemokine-miRNA target pairs, data from miRNA target prediction databases were combined with valvular miRNA and mRNA expression profiles. MiR-125b was computationally predicted to target CCL4, as confirmed experimentally in cultured human THP-1 macrophages. Collectively, miR-125b and CCL4 appear to be involved in the progression of CAVD and may offer novel therapeutic and diagnostic strategies related to this disease.

Role of osteopontin in the pathophysiology of cancer

Osteopontin (OPN) is a multifunctional cytokine that impacts cell proliferation, survival, drug resistance, invasion, and stem like behavior. Due to its critical involvement in regulating cellular functions, its aberrant expression and/or splicing is functionally responsible for undesirable alterations in disease pathologies, specifically cancer. It is implicated in promoting invasive and metastatic progression of many carcinomas. Due to its autocrine and paracrine activities OPN has been shown to be a crucial mediator of cellular cross talk and an influential factor in the tumor microenvironment. OPN has been implicated as a prognostic and diagnostic marker for several cancer types. It has also been explored as a possible target for treatment. In this article we hope to provide a broad perspective on the importance of OPN in the pathophysiology of cancer.

Osteopontin Promotes EZH2 Expression and Tumor Progression in Nasopharyngeal Carcinoma

<b><i>Objective:</i></b> To evaluate the possible mechanism of osteopontin (OPN) in the tumor progression of nasopharyngeal carcinoma (NPC). <b><i>Methods:</i></b> Twenty NPC specimens and 10 normal biopsy specimens were analyzed, and the expression of OPN and enhancer of zeste homolog 2 (EZH2) was examined by immunohistochemical staining. Moreover, the expression of EZH2 in NPC cell lines was examined using quantitative reverse transcription polymerase chain reaction and Western blot analysis in the presence of recombinant human (rh) OPN and specific inhibitors. NPC cell migration and invasion were evaluated using a transwell chamber in the presence of rhOPN and/or EZH2 siRNA. <b><i>Results:</i></b> The immunoreactivity of OPN and EZH2 was significantly enhanced in NPC specimens compared with the normal controls (p < 0.05). EZH2 expression in NPC specimens was significantly associated with OPN expression and tumor stage (p < 0.05). Moreover, rhOPN significantly stimulated EZH2 expression in the NPC cell line through a MAPK-mediated pathway and significantly stimulated migration and invasion of the NPC cell line (p < 0.05), which was notably inhibited by EZH2 siRNA transfection (p < 0.05). <b><i>Conclusion:</i></b> Our findings suggest that OPN may promote tumor progression of NPC through an EZH2-dependent pathway. i 2014 S. Karger AG, Basel