Osteopontin is a prognostic biomarker in non-small cell lung cancer

Prognostic and clinicopathological value of osteopontin expression in non-small cell lung cancer: a meta-analysis and systematic review

BACKGROUND

Although Osteopontin (OPN) has been reported to be associated with many different human cancers, the data on non-small cell lung cancer (NSCLC) are not definitive. This study aimed to explore the prognostic effect of OPN expression and clinicopathological characteristics in patients with NSCLC.

METHODS

This study followed all aspects of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) report. PubMed, Embase and the Cochrane Library were searched to identify the relative studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to estimate the prognostic value of the OPN in patients with NSCLC. The odds ratio (OR) was calculated to represent the relationship between OPN expression and clinicopathological parameters.

RESULTS

A total of fifteen studies with 2173 participants were finally included. The results revealed that high expression of OPN was significantly associated with poorer overall survival (OS) (HR = 1.89; 95%CI = 1.68-2.11; p < 0.001). Moreover, a significant correlation was observed between increased OPN expression and poorly differentiated (well and moderately differentiated vs. poorly differentiated; pooled OR = 0.38; 95% CI = 0.23-0.64; p < 0.001), lymph node metastasis (absence vs. presence; pooled OR = 0.49; 95%CI = 0.32-0.74; p < 0.001), and distant metastasis (absence vs. presence; pooled OR = 0.18; 95%CI = 0.11-0.29; p < 0.001).

CONCLUSION

This meta-analysis implies that OPN might be a valuable biomarker for a poor prognosis and poor clinicopathological outcomes for patients with NSCLC.

Common Variants in Osteopontin and CD44 Genes as Predictors of Treatment Outcome in Radiotherapy and Chemoradiotherapy for Non-Small Cell Lung Cancer

Osteopontin (OPN)-CD44 signaling plays an important role in promoting tumor progression and metastasis. In cancer, OPN and CD44 overexpression is a marker of aggressive disease and poor prognosis, and correlates with therapy resistance. In this study, we aimed to evaluate the association of single nucleotide polymorphisms (SNPs) in the OPN and CD44 genes with clinical outcomes in 307 non-small cell lung cancer (NSCLC) patients treated with radiotherapy or chemoradiotherapy. The potential impact of the variants on plasma OPN levels was also investigated. Multivariate analysis showed that OPN rs11730582 CC carriers had a significantly increased risk of death (p = 0.029), while the CD44 rs187116 A allele correlated with a reduced risk of locoregional recurrence (p = 0.016) in the curative treatment subset. The rs11730582/rs187116 combination was associated with an elevated risk of metastasis in these patients (p = 0.016). Furthermore, the OPN rs1126772 G variant alone (p = 0.018) and in combination with rs11730582 CC (p = 7 × 10-5) was associated with poor overall survival (OS) in the squamous cell carcinoma subgroup. The rs11730582 CC, rs187116 GG, and rs1126772 G, as well as their respective combinations, were independent risk factors for unfavorable treatment outcomes. The impact of rs11730582-rs1126772 haplotypes on OS was also observed. These data suggest that OPN and CD44 germline variants may predict treatment effects in NSCLC.

A Review of Biomarkers and Their Clinical Impact in Resected Early-Stage Non-Small-Cell Lung Cancer

The postoperative survival of early-stage non-small-cell lung cancer (NSCLC) patients remains unsatisfactory. In this review, we examined the relevant literature to ascertain the prognostic effect of related indicators on early-stage NSCLC. The prognostic effects of the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), mesenchymal-epithelial transition (MET), C-ros oncogene 1 (ROS1), or tumour protein p53 (TP53) alterations in resected NSCLC remains debatable. Kirsten rat sarcoma viral oncogene homologue (KRAS) alterations indicate unfavourable outcomes in early-stage NSCLC. Meanwhile, adjuvant or neoadjuvant EGFR-targeted agents can substantially improve prognosis in early-stage NSCLC with EGFR alterations. Based on the summary of current studies, resected NSCLC patients with overexpression of programmed death-ligand 1 (PD-L1) had worsening survival. Conversely, PD-L1 or PD-1 inhibitors can substantially improve patient survival. Considering blood biomarkers, perioperative peripheral venous circulating tumour cells (CTCs) and pulmonary venous CTCs predicted unfavourable prognoses and led to distant metastases. Similarly, patients with detectable perioperative circulating tumour DNA (ctDNA) also had reduced survival. Moreover, patients with perioperatively elevated carcinoembryonic antigen (CEA) in the circulation predicted significantly worse survival outcomes. In the future, we will incorporate mutated genes, immune checkpoints, and blood-based biomarkers by applying artificial intelligence (AI) to construct prognostic models that predict patient survival accurately and guide individualised treatment.

Machine learning for prediction of immunotherapeutic outcome in non-small-cell lung cancer based on circulating cytokine signatures

BACKGROUND

Immune checkpoint inhibitor (ICI) therapy has substantially improved the overall survival (OS) in patients with non-small-cell lung cancer (NSCLC); however, its response rate is still modest. In this study, we developed a machine learning-based platform, namely the Cytokine-based ICI Response Index (CIRI), to predict the ICI response of patients with NSCLC based on the peripheral blood cytokine profiles.

METHODS

We enrolled 123 and 99 patients with NSCLC who received anti-PD-1/PD-L1 monotherapy or combined chemotherapy in the training and validation cohorts, respectively. The plasma concentrations of 93 cytokines were examined in the peripheral blood obtained from patients at baseline (pre) and 6 weeks after treatment (early during treatment: edt). Ensemble learning random survival forest classifiers were developed to select feature cytokines and predict the OS of patients undergoing ICI therapy.

RESULTS

Fourteen and 19 cytokines at baseline and on treatment, respectively, were selected to generate CIRI models (namely preCIRI14 and edtCIRI19), both of which successfully identified patients with worse OS in two completely independent cohorts. At the population level, the prediction accuracies of preCIRI14 and edtCIRI19, as indicated by the concordance indices (C-indices), were 0.700 and 0.751 in the validation cohort, respectively. At the individual level, patients with higher CIRI scores demonstrated worse OS [hazard ratio (HR): 0.274 and 0.163, and p<0.0001 and p=0.0044 in preCIRI14 and edtCIRI19, respectively]. By including other circulating and clinical features, improved prediction efficacy was observed in advanced models (preCIRI21 and edtCIRI27). The C-indices in the validation cohort were 0.764 and 0.757, respectively, whereas the HRs of preCIRI21 and edtCIRI27 were 0.141 (p<0.0001) and 0.158 (p=0.038), respectively.

CONCLUSIONS

The CIRI model is highly accurate and reproducible in determining the patients with NSCLC who would benefit from anti-PD-1/PD-L1 therapy with prolonged OS and may aid in clinical decision-making before and/or at the early stage of treatment.

Quercetin can be a more reliable treatment for metastatic prostate cancer than the localized disease: An in vitro study

Quercetin is a plant flavonoid that has been recognized to have anti-inflammatory, antioxidant and anti-proliferative activities. This study aims to evaluate the inhibitory effects of quercetin against prostate malignancy in vitro and the underlying resistance mechanism. IC50 values of quercetin were determined by MTT assay. Annexin-V/PI staining was used to measure the rate of apoptosis. DNA cell cycle was analysed by PI staining method. Real-time PCR was performed to assess mRNA levels of OPN isoforms, VEGF isoforms, P53 and KLK2. Migration potential, proliferative capability and nucleus morphology of cells were evaluated by the scratch-wound assay, colony-forming assay and Hoechst staining, respectively. Quercetin significantly increased the apoptosis rate of PC-3 and LNCaP cell lines, arrested the cell cycle at the sub-G1/G1 phase, and reduced the migration potential and colony-forming capability. Moreover, upregulation of apoptosis-related genes and downregulation of genes involved in proliferation and angiogenesis was also observed. Although our results elucidated that quercetin has antitumor effects on PC-3 and LNCaP, for the first time, we showed that quercetin treatment causes alterations in the expression of OPN and VEGF isoforms, which are cancer-promoting modulators through various processes such as angiogenesis and drug-resistance. Prostate malignant cells can dodge the anti-carcinogenic properties of quercetin via modulation of OPN and VEGF isoforms in vitro. Therefore, quercetin acts as a double-edged sword in prostate cancer treatment.

"Evaluation of ROS1 expression and rearrangements in a large cohort of early-stage lung cancer"

BACKGROUND

ROS1 fusion is an infrequent, but attractive target for therapy in patients with metastatic non- small-cell lung cancer. In studies on mainly late-stage disease, the prevalence of ROS1 fusions is about 1-3%. In early-stage lung cancer ROS1 might also provide a fruitful target for neoadjuvant or adjuvant therapy. In the present study, we investigated the prevalence of ROS1 fusion in a Norwegian cohort of early-stage lung cancer. We also explored whether positive ROS1 immunohistochemical (IHC) stain was associated with certain mutations, clinical characteristics and outcomes.

METHODS

The study was performed using biobank material from 921 lung cancer patients including 542 patients with adenocarcinoma surgically resected during 2006-2018. Initially, we screened the samples with two different IHC clones (D4D6 and SP384) targeting ROS1. All samples that showed more than weak or focal staining, as well as a subgroup of negative samples, were analyzed with ROS1 fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) with a comprehensive NGS DNA and RNA panel. Positive ROS1-fusion was defined as those samples positive in at least two of the three methods (IHC, FISH, NGS).

RESULTS

Fifty cases were IHC positive. Of these, three samples were both NGS and FISH-positive and considered positive for ROS1 fusion. Two more samples were FISH positive only, and whilst IHC and NGS were negative. These were also negative with Reverse Transcription quantitative real time Polymerase Chain Reaction (RT-qPCR). The prevalence of ROS1 fusion in adenocarcinomas was 0.6%. All cases with ROS1 fusion had TP53 mutations. IHC-positivity was associated with adenocarcinoma. Among SP384-IHC positive cases we also found an association with never smoking status. There was no association between positive IHC and overall survival, time to relapse, age, stage, sex or pack-year of smoking.

CONCLUSIONS

ROS1 seems to be less frequent in early-stage disease than in advanced stages. IHC is a sensitive, but less specific method and the results need to be confirmed with another method like FISH or NGS.

The Significance of SPP1 in Lung Cancers and Its Impact as a Marker for Protumor Tumor-Associated Macrophages

Macrophages are a representative cell type in the tumor microenvironment. Macrophages that infiltrate the cancer microenvironment are referred to as tumor-associated macrophages (TAMs). TAMs exhibit protumor functions related to invasion, metastasis, and immunosuppression, and an increased density of TAMs is associated with a poor clinical course in many cancers. Phosphoprotein 1 (SPP1), also known as osteopontin, is a multifunctional secreted phosphorylated glycoprotein. Although SPP1 is produced in a variety of organs, at the cellular level, it is expressed on only a few cell types, such as osteoblasts, fibroblasts, macrophages, dendritic cells, lymphoid cells, and mononuclear cells. SPP1 is also expressed by cancer cells, and previous studies have demonstrated correlations between levels of circulating SPP1 and/or increased SPP1 expression on tumor cells and poor prognosis in many types of cancer. We recently revealed that SPP1 expression on TAMs is correlated with poor prognosis and chemoresistance in lung adenocarcinoma. In this review, we summarize the significance of TAMs in lung cancers and discuss the importance of SPP1 as a new marker for the protumor subpopulation of monocyte-derived TAMs in lung adenocarcinoma. Several studies have shown that the SPP1/CD44 axis contribute to cancer chemoresistance in solid cancers, so the SPP1/CD44 axis may represent one of the most critical mechanisms for cell-to-cell communication between cancer cells and TAMs.

IRF8: Mechanism of Action and Health Implications

Interferon regulatory factor 8 (IRF8) is a transcription factor of the IRF protein family. IRF8 was originally identified as an essentialfactor for myeloid cell lineage commitment and differentiation. Deletion of Irf8 leads to massive accumulation of CD11b⁺Gr1⁺ immature myeloid cells (IMCs), particularly the CD11b⁺Ly6C^hi/+Ly6G⁻ polymorphonuclear myeloid-derived suppressor cell-like cells (PMN-MDSCs). Under pathological conditions such as cancer, Irf8 is silenced by its promoter DNA hypermethylation, resulting in accumulation of PMN-MDSCs and CD11b⁺ Ly6G⁺Ly6C^lo monocytic MDSCs (M-MDSCs) in mice. IRF8 is often silenced in MDSCs in human cancer patients. MDSCs are heterogeneous populations of immune suppressive cells that suppress T and NK cell activity to promote tumor immune evasion and produce growth factors to exert direct tumor-promoting activity. Emerging experimental data reveals that IRF8 is also expressed in non-hematopoietic cells. Epithelial cell-expressed IRF8 regulates apoptosis and represses Osteopontin (OPN). Human tumor cells may use the IRF8 promoter DNA methylation as a mechanism to repress IRF8 expression to advance cancer through acquiring apoptosis resistance and OPN up-regulation. Elevated OPN engages CD44 to suppress T cell activation and promote tumor cell stemness to advance cancer. IRF8 thus is a transcription factor that regulates both the immune and non-immune components in human health and diseases.

The Clinical Impact of the EPH/Ephrin System in Cancer: Unwinding the Thread

Erythropoietin-producing human hepatocellular receptors (EPHs) compose the largest known subfamily of receptor tyrosine kinases (RTKs). They bind and interact with the EPH family receptor interacting proteins (ephrins). EPHs/ephrins are implicated in a variety of physiological processes, as well as in cancer pathogenesis. With neoplastic disease remaining a leading cause of death world-wide, the development of novel biomarkers aiding in the field of diagnosis, prognosis, and disease monitoring is of utmost importance. A multitude of studies have proven the association between the expression of members of the EPH/ephrin system and various clinicopathological parameters, including disease stage, tumor histologic grade, and patients' overall survival. Besides their utilization in timely disease detection and assessment of outcome, EPHs/ephrins could also represent possible novel therapeutic targets. The aim of the current review of the literature was to present the existing data regarding the association between EPH/ephrin system expression and the clinical characteristics of malignant tumors.

Osteopontin improves sensitivity to tyrosine kinase inhibitor in lung adenocarcinoma in vitro by promoting epidermal growth factor receptor phosphorylation

PURPOSE

Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) improve the prognosis of lung adenocarcinoma (LUAD). However, the factors affecting its clinical efficacy remain unclear. This study aimed to determine the correlation between Osteopontin (OPN) and EGFR, and explore the inhibitory effect of first-generation TKI gefitinib on LUAD cells.

METHODS

The correlation between OPN and EGFR was determined through bioinformatics technology, and the clinical information as well as samples of related patients were collected to verify the relationship between them. Using three different NSCLC cell lines A549, H1299 and PC9, we studied the effects of OPN expression and EGFR phosphorylation on the first-generation TKI's efficacy in vitro.

RESULTS

Our data revealed that OPN staining positively linked to a more advanced clinical stage. Compared with the control group, LUAD cells with elevated OPN levels are more sensitive to the growth inhibitory effect of TKI. Knocking down of OPN decreased the response of cells to gefitinib. Besides, OPN also upregulated the phosphorylation of EGFR, thereby affecting the effect of TKI.

CONCLUSION

OPN enhanced the sensitivity of LUAD cells to gefitinib by promoting EGFR phosphorylation. OPN may be a potential target for evaluating TKI efficacy and a potential target for molecular therapy.

Osteopontin drives KRAS-mutant lung adenocarcinoma

Increased expression of osteopontin (secreted phosphoprotein 1, SPP1) is associated with aggressive human lung adenocarcinoma (LADC), but its function remains unknown. Our aim was to determine the role of SPP1 in smoking-induced LADC. We combined mouse models of tobacco carcinogen-induced LADC, of deficiency of endogenous Spp1 alleles, and of adoptive pulmonary macrophage reconstitution to map the expression of SPP1 and its receptors and determine its impact during carcinogenesis. Co-expression of Spp1 and mutant KrasG12C in benign cells was employed to investigate SPP1/KRAS interactions in oncogenesis. Finally, intratracheal adenovirus encoding Cre recombinase was delivered to LSL.KRASG12D mice lacking endogenous or overexpressing transgenic Spp1 alleles. SPP1 was overexpressed in experimental and human LADC and portended poor survival. In response to two different smoke carcinogens, Spp1-deficient mice developed fewer and smaller LADC with decreased cellular survival and angiogenesis. Both lung epithelial- and macrophage-secreted SPP1 drove tumor-associated inflammation, while epithelial SPP1 promoted early tumorigenesis by fostering the survival of KRAS-mutated cells. Finally, loss and overexpression of Spp1 was, respectively, protective and deleterious for mice harboring KRASG12D-driven LADC. Our data support that SPP1 is functionally involved in early stages of airway epithelial carcinogenesis driven by smoking and mutant KRAS and may present an important therapeutic target.

High expression of SPP1 in patients with chronic obstructive pulmonary disease (COPD) is correlated with increased risk of lung cancer

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airway inflammation and fixed airflow obstruction. Patients with COPD have increased risk of lung cancer (LC), and the coexistence of both diseases is associated with poorer survival. However, the mechanisms predisposing patients with COPD to LC development and poor prognosis remain unclear. Gene expression profiles were downloaded from the Gene Expression Omnibus. Twenty‐two data sets were included (n = 876). We identified 133 DEGs and 145 DEGs in patients with COPD and LC compared with healthy controls, respectively. There were 1544 DEGs in patients with LC and coexisting COPD compared with COPD, and these DEGs are mainly involved in the cell cycle, DNA replication, p53 signalling and insulin signalling. The biological processes primarily associated with these DEGs are oxidation reduction and apoptosis. SPP1 was the only overlapping DEG that was up‐regulated in patients with COPD and/or LC, and this was validated by qPCR in an independent cohort. The area under the curve value for SPP1 was 0.893 (0.822–0.963) for the prediction of LC in patients with COPD. High expression of SPP1 in patients with LC was associated with shorter survival time. Up‐regulation of SPP1 may be associated with increased risk of LC in patients with COPD and therefore may have potential as a therapeutic target for LC in patients with COPD.

Immunogenic Chemotherapy Enhances Recruitment of CAR-T Cells to Lung Tumors and Improves Antitumor Efficacy when Combined with Checkpoint Blockade

Adoptive therapy using chimeric antigen receptor-modified T cells (CAR-T cells) is effective in hematologic but not epithelial malignancies, which cause the greatest mortality. In breast and lung cancer patients, CAR-T cells targeting the tumor-associated antigen receptor tyrosine kinase-like orphan receptor 1 (ROR1) infiltrate tumors poorly and become dysfunctional. To test strategies for enhancing efficacy, we adapted the Kras^LSL-G12D/+;p53^f/f autochthonous model of lung adenocarcinoma to express the CAR target ROR1. Murine ROR1 CAR-T cells transferred after lymphodepletion with cyclophosphamide (Cy) transiently control tumor growth but infiltrate tumors poorly and lose function, similar to what is seen in patients. Adding oxaliplatin (Ox) to the lymphodepletion regimen activates tumor macrophages to express T-cell-recruiting chemokines, resulting in improved CAR-T cell infiltration, remodeling of the tumor microenvironment, and increased tumor sensitivity to anti-PD-L1. Combination therapy with Ox/Cy and anti-PD-L1 synergistically improves CAR-T cell-mediated tumor control and survival, providing a strategy to improve CAR-T cell efficacy in the clinic.

Osteopontin: A Key Regulator of Tumor Progression and Immunomodulation

Simple Summary

Anti-PD-1/PD-L1 and anti-CTLA-4-based immune checkpoint blockade (ICB) immunotherapy have recently emerged as a breakthrough in human cancer treatment. Durable efficacy has been achieved in many types of human cancers. However, not all human cancers respond to current ICB immunotherapy and only a fraction of the responsive cancers exhibit efficacy. Osteopontin (OPN) expression is highly elevated in human cancers and functions as a tumor promoter. Emerging data suggest that OPN may also regulate immune cell function in the tumor microenvironment. This review aims at OPN function in human cancer progression and new findings of OPN as a new immune checkpoint. We propose that OPN compensates PD-L1 function to promote tumor immune evasion, which may underlie human cancer non-response to current ICB immunotherapy.

Abstract

OPN is a multifunctional phosphoglycoprotein expressed in a wide range of cells, including osteoclasts, osteoblasts, neurons, epithelial cells, T, B, NK, NK T, myeloid, and innate lymphoid cells. OPN plays an important role in diverse biological processes and is implicated in multiple diseases such as cardiovascular, diabetes, kidney, proinflammatory, fibrosis, nephrolithiasis, wound healing, and cancer. In cancer patients, overexpressed OPN is often detected in the tumor microenvironment and elevated serum OPN level is correlated with poor prognosis. Initially identified in activated T cells and termed as early T cell activation gene, OPN links innate cells to adaptive cells in immune response to infection and cancer. Recent single cell RNA sequencing revealed that OPN is primarily expressed in tumor cells and tumor-infiltrating myeloid cells in human cancer patients. Emerging experimental data reveal a key role of OPN is tumor immune evasion through regulating macrophage polarization, recruitment, and inhibition of T cell activation in the tumor microenvironment. Therefore, in addition to its well-established direct tumor cell promotion function, OPN also acts as an immune checkpoint to negatively regulate T cell activation. The OPN protein level is highly elevated in peripheral blood of human cancer patients. OPN blockade immunotherapy with OPN neutralization monoclonal antibodies (mAbs) thus represents an attractive approach in human cancer immunotherapy.

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.

Prognostic value of OCT4A and SPP1C transcript variant co-expression in early-stage lung adenocarcinoma

BACKGROUND

Octamer-binding transcription factor 4A (OCT4A) is essential for cell pluripotency and reprogramming both in humans and mice. To date, however, the function of human OCT4 in somatic and/or tumour tissues is largely unknown.

METHODS

RT-PCR was used to identify full-length splice forms of OCT4 transcripts in normal and cancer cells. A FLAG-tagged OCT4 genomic transgene was used to identify OCT4-positive cancer cells. A potential role for OCT4 in somatic cancer cells was examined by cell ablation of OCT4-positive cells using promoter-driven diphtheria toxin A. OCT4 and secreted phosphoprotein 1 (SPP1) transcripts in early-stage lung adenocarcinoma tumours were analysed and compared with pathohistological features.

RESULTS

The results show that, unlike in murine cells, OCT4A and OCT4B variants are transcribed in both human cancer cells and in adult tissues such as lung, kidney, uterus, breast, and eye. We found that OCT4A and SPP1C are co-expressed in highly aggressive human breast, endometrial, and lung adenocarcinoma cell lines, but not in mesothelial tumour cell lines. Ablation of OCT4-positive cells in lung adenocarcinoma cells significantly decreased cell migration and SPP1C mRNA levels. The OCT4A/SPP1C axis was found in primary, early-stage, lung adenocarcinoma tumours.

CONCLUSIONS

Co-expression of OCT4 and SPP1 may correlate with cancer aggressiveness, and the OCT4A/SPP1C axis may help identify early-stage high-risk patients with lung adenocarcinoma. Contrary to the case in mice, our data strongly suggest a critical role for OCT4A and SPP1C in the development and progression of human epithelial cancers.

Osteopontin as a Link between Inflammation and Cancer: The Thorax in the Spotlight

The glycoprotein osteopontin (OPN) possesses multiple functions in health and disease. To this end, osteopontin has beneficial roles in wound healing, bone homeostasis, and extracellular matrix (ECM) function. On the contrary, osteopontin can be deleterious for the human body during disease. Indeed, osteopontin is a cardinal mediator of tumor-associated inflammation and facilitates metastasis. The purpose of this review is to highlight the importance of osteopontin in malignant processes, focusing on lung and pleural tumors as examples.

Osteopontin expression is associated with progression and adverse prognosis in patients with resectable gastrointestinal stromal tumor

OBJECTIVES

Osteopontin (OPN) is reported to be particularly associated with the progression of several human malignancies. This study was designed to examine the clinicopathologic significance of OPN in gastrointestinal stromal tumor (GISTs).

METHODS

The level of OPN expression in a large cohort of resectable GISTs was evaluated with immunohistochemistry. Its correlation with the clinicopathologic parameters of patients with resectable GISTs was analyzed. A survival analysis was performed to evaluate the prognostic significance of OPN expression using the Kaplan-Meier method.

RESULTS

In 108 patients with resectable GISTs, the most high-risk GISTs had a strong level of OPN expression. Strong OPN expression was also significantly associated with tumor size, mitosis, and recurrence, but not gender and age. Patients with weak OPN expression had a relatively longer disease-free survival compared to patients with strong OPN expression.

CONCLUSIONS

OPN expression is a putative marker for tumor progression and an adverse prognosis in GISTs.

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.

SIRT1 overexpression protects non-small cell lung cancer cells against osteopontin-induced epithelial-mesenchymal transition by suppressing NF-κB signaling

Osteopontin (OPN) is a promoter for tumor progression. It has been reported to promote non-small cell lung cancer (NSCLC) progression via the activation of nuclear factor-κB (NF-κB) signaling. As the increased acetylation of NF-κB p65 is linked to NF-κB activation, the regulation of NF-κB p65 acetylation could be a potential treatment target for OPN-induced NSCLC progression. Sirtuin 1 (SIRT1) is a deacetylase, and the role of SIRT1 in tumor progression is still controversial. The effect and mechanism of SIRT1 on OPN-induced tumor progression remains unknown. The results presented in this research demonstrated that OPN inhibited SIRT1 expression and promoted NF-κB p65 acetylation in NSCLC cell lines (A549 and NCI-H358). In this article, overexpression of SIRT1 was induced by infection of SIRT1-overexpressing lentiviral vectors. The overexpression of SIRT1 protected NSCLC cells against OPN-induced NF-κB p65 acetylation and epithelial-mesenchymal transition (EMT), as indicated by the reduction of OPN-induced changes in the expression levels of EMT-related markers and cellular morphology. Furthermore, SIRT1 overexpression significantly attenuated OPN-induced cell proliferation, migration and invasion. Moreover, overexpression of SIRT1 inhibited OPN-induced NF-κB activation. As OPN induced NSCLC cell EMT through activation of NF-κB signaling, OPN-induced SIRT1 downregulation may play an important role in NSCLC cell EMT via NF-κB signaling. The results suggest that SIRT1 could be a tumor suppressor to attenuate OPN-induced NSCLC progression through the regulation of NF-κB signaling.

Serum osteopontin in patients with lung cancer and chronic obstructive pulmonary disease: does the co-existence make the difference?

Background

Osteopontin (OPN) is involved in cancer development and metastasis. Increased sputum OPN was detected in chronic obstructive pulmonary disease (COPD).

Methods

We evaluated serum OPN levels in patients with lung cancer (LC) and/or COPD and aimed to determine OPN prognostic performance in 1-year mortality in LC and also its diagnostic performance in LC among COPD patients. We recruited 167 LC patients, 85 with concomitant COPD. 28 COPD patients served as control group.

Results

OPN levels were higher in LC compared to COPD alone (P=0.017) and higher in COPD and LC compared to COPD alone (P=0.031). No difference was observed in OPN levels between LC and COPD vs. LC without COPD (P=0.171). Serum OPN ≥50.3 ng/mL was an independent predictor of 1-year mortality in LC.

Conclusions

OPN levels ≥35 ng/mL could predict the presence of LC among COPD patients. In patients with LC and/or COPD, LC is the major determinant for serum OPN. Serum OPN might be a promising prognostic biomarker of LC and a diagnostic biomarker of LC among COPD patients.

Osteopontin: its potential role in cancer of children and young adults

Objective: Osteopontin (OPN) is aglyco-phosphoprotein, involved in tissue remodeling, inflammation and boneresorption. In various adult neoplasms OPN was shown to correlate with cancer progression, invasiveness and metastasis. Aim: to define the role of OPN in malignancies of children and young adults. Material and methods: a structured PubMed and Google Scholar literature analysis based on reports published in English between I'1995 and XII'2015. Results: 14 studies (four on hematological malignancies, four on bone tumors, three on CNS tumors, two on dendritic proliferative diseases and one on renal tumors) were identified. Higher levels of serum and cerebro-spinal fluid OPN protein, and high expressions of OPN mRNA and SPP1 gene were present in more aggressive and advanced childhood malignancies. In children with acute lymphoblastic leukemia with CNS involvement and with atypical teratoid/rhabdoid tumor (AT/RT) and medulloblastoma, the serum and CSF OPN levels reflected tumor bulk and response to therapy, while in children with AT/RT and multisystem Langerhans cell histiocytosis with high-risk organs involvement, high OPN serum levels correlated with poorer survival. To the contrary, in osteosarcoma, high OPN mRNA and SPP1 gene expressions correlated with better survival and good response to chemotherapy. Conclusions: The literature review suggests that OPN may play important roles in the development and progression of selected cancers of children and young adults, including acute lymphoblastic leukemia, malignant gliomas, AT/RT and Langerhans cell histiocytosis. However, limited number of published studies prevents from definite concluding on the clinical utility of OPN as a marker of diagnosis, prognosis and treatment monitoring in these pediatric cancers. Further studies performed in more numerous groups of patients with particular types of cancers of children and young adults are warranted.

Runx3 and Cell Fate Decisions in Pancreas Cancer

The RUNX family transcription factors are critical regulators of development and frequently dysregulated in cancer. RUNX3, the least well characterized of the three family members, has been variously described as a tumor promoter or suppressor, sometimes with conflicting results and opinions in the same cancer and likely reflecting a complex role in oncogenesis. We recently identified RUNX3 expression as a crucial determinant of the predilection for pancreatic ductal adenocarcinoma (PDA) cells to proliferate locally or promulgate throughout the body. High RUNX3 expression induces the production and secretion of soluble factors that support metastatic niche construction and stimulates PDA cells to migrate and invade, while simultaneously suppressing proliferation through increased expression of cell cycle regulators such as CDKN1A/p21 ^WAF1/CIP1 . RUNX3 expression and function are coordinated by numerous transcriptional and post-translational inputs, and interactions with diverse cofactors influence whether the resulting RUNX3 complexes enact tumor suppressive or tumor promoting programs. Understanding these exquisitely context-dependent tumor cell behaviors has the potential to inform clinical decision-making including the most appropriate timing and sequencing of local vs. systemic therapies.

Osteopontin and thrombospondin-1 play opposite roles in promoting tumor aggressiveness of primary resected non-small cell lung cancer

Background

Osteopontin (OPN) and thrombospondin-1 (TSP-1) are extracellular matrix proteins secreted by stromal and tumor cells. These proteins appear to have a key role in the tumor microenvironment for cancer development and metastasis. There is little information regarding the prognostic value of the combination of these two proteins in human cancers. Our aim was to clarify clinical significance and prognostic value of each circulating protein and their combination in primary resected non-small cell lung cancer (NSCLC) patients.

Methods

We retrospectively reviewed 171 patients with NSCLC following curative intent surgery from January to December of 2012. Preoperative serums, demographics, clinical and pathological data and molecular profiling were analyzed. Pre-treatment OPN and TSP-1 serum levels were measured by ELISA. Tissue protein expression in primary tumor samples was determined by immunohistochemical analysis.

Results

OPN and TSP-1 serum levels were inversely correlated with survival rates. For each 50 units increment of serum OPN, an increased risk of metastasis by 69 % (unadjusted HR 1.69, 95 % CI 1.12–2.56, p = 0.01) and an increased risk of death by 95 % (unadjusted HR 1.95, 95 % CI 1.15–3.32, p = 0.01) were observed. Conversely, for each 10 units increment in TSP-1, the risk of death was decreased by 85 % (unadjusted HR 0.15, 95 % CI 0.03–0.89; p = 0.04). No statistically significant correlation was found between TSP-1 serum level and distant metastasis-free survival (p = 0.2). On multivariate analysis, OPN and TSP-1 serum levels were independent prognostic factors of overall survival (HR 1.71, 95 % CI 1.04–2.82, p = 0.04 for an increase of 50 ng/mL in OPN; HR 0.18, 95 % CI 0.04–0.87, p = 0.03 for an increase of 10 ng/mL in TSP-1). In addition, the combination of OPN and TSP-1 serum levels remained an independent prognostic factor for overall survival (HR 1.31, 95 % CI 1.03–1.67, p = 0.03 for an increase of 6 ng/mL in OPN/TSP-1 ratio).

Conclusions

Our results show that pre-treatment OPN and TSP-1 serum levels may reflect the aggressiveness of the tumor and might serve as prognostic markers in patients with primary resected NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2541-5) contains supplementary material, which is available to authorized users.

Osteopontin in cerebrospinal fluid as diagnostic biomarker for central nervous system lymphoma

Central nervous system lymphoma (CNSL) is diagnostically challenging. The identification of reliable and easy to measure biomarkers is desirable to facilitate diagnosis. Here, we evaluated the value of cerebrospinal fluid (CSF) osteopontin (OPN) as a diagnostic biomarker for CNSL. OPN concentrations in CSF from 37 patients with CNSL (29 with primary CNSL and 8 with secondary CNS involvement of systemic lymphoma) and 36 controls [6 patients with inflammatory CNS disease other than multiple sclerosis (MS), 8 with MS, 9 with glioblastoma (GBM) and 13 healthy controls] were determined using an enzyme-linked immunosorbent assay. Non-parametric tests and receiver operating characteristic (ROC) curves were performed for determination of diagnostic accuracy. Median CSF OPN level in all CNSL patients was 620 ng/mL and higher than in patients with inflammatory CNS disease (356 ng/mL); P < .05, MS (163 ng/mL); P < .01, GBM (41 ng/mL); P < .01, or healthy controls (319 ng/mL); P < .01. The area under the ROC curve was 0.865 [95 % confidence interval (CI) 0.745-0.985] for differentiating CNSL and patients with inflammatory CNS disease; 0.956 (95 % CI 0.898-1.000) for CNSL and MS patients; 0.988 (95 % CI 0.964-1.000) for CNSL and GBM patients, and 0.915 (95 % CI 0.834-0.996) for CNSL patients and healthy controls. In multivariate analysis, high CSF OPN level was associated with shorter progression-free (HR 1.61, 95 % CI 1.13-2.31; P = .009) and overall survival (HR 1.52, 95 % CI 1.04-2.21; P = .029). CSF OPN is a potential biomarker in CNSL.

Prognostic value of blood-biomarkers related to hypoxia, inflammation, immune response and tumour load in non-small cell lung cancer - A survival model with external validation

AIM

Improve the prognostic prediction of clinical variables for non-small cell lung cancer (NSCLC), by selecting from blood-biomarkers, non-invasively describing hypoxia, inflammation and tumour load.

METHODS

Model development and validation included 182 and 181 inoperable stage I-IIIB NSCLC patients treated radically with radiotherapy (55.2%) or chemo-radiotherapy (44.8%). Least absolute shrinkage and selection operator (LASSO), selected from blood-biomarkers related to hypoxia [osteopontin (OPN) and carbonic anhydrase IX (CA-IX)], inflammation [interleukin-6 (IL-6), IL-8, and C-reactive protein (CRP)], and tumour load [carcinoembryonic antigen (CEA), and cytokeratin fragment 21-1 (Cyfra 21-1)]. Sequent model extension selected from alpha-2-macroglobulin (α2M), serum interleukin-2 receptor (sIL2r), toll-like receptor 4 (TLR4), and vascular endothelial growth factor (VEGF). Discrimination was reported by concordance-index.

RESULTS

OPN and Cyfra 21-1 (hazard ratios of 3.3 and 1.7) significantly improved a clinical model comprising gender, World Health Organization performance-status, forced expiratory volume in 1s, number of positive lymph node stations, and gross tumour volume, from a concordance-index of 0.66 to 0.70 (validation=0.62 and 0.66). Extension of the validated model yielded a concordance-index of 0.67, including α2M, sIL2r and VEGF (hazard ratios of 4.6, 3.1, and 1.4).

CONCLUSION

Improvement of a clinical model including hypoxia and tumour load blood-biomarkers was validated. New immunological markers were associated with overall survival. Data and models can be found at www.cancerdata.org (http://dx.doi.org/10.17195/candat.2016.04.1) and www.predictcancer.org.

Correlation between lung neoplasm and serum level of osteopontin: A meta-analysis

The aim of this meta-analysis was to evaluate the clinical significance of serum osteopontin (OPN) levels in lung neoplasm in patients to establish a novel diagnostic score model. Articles were identified by searching the PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure, and Wang Fang databases. Studies identified were pooled, and the standardized mean difference (SMD) and its corresponding 95% confidence interval (CI) were calculated. Subgroup analyses and publication bias detection were also conducted. Version 12.0 STATA software was used for statistical analysis. A final analysis of 1,327 subjects together (740 patients with lung neoplasms and 587 controls) was performed from 10 clinical case-control studies. The meta-analysis results showed a positive association between serum OPN levels and lung neoplasm (SMD=5.59, 95% CI: 1.85–3.32, P<0.001). The subgroup analysis by ethnicity detected that high levels of serum OPN may be the main risk factor for lung neoplasms in Asians (SMD=1.76, 95% CI: 1.24–2.29, P<0.001), but not in Caucasians (P=0.072). In conclusion, the present meta-analysis indicated that serum OPN levels were generally elevated in lung neoplasm patients, and thus, serum levels of OPN may be useful in diagnosing lung neoplasm in certain population groups.

The association between osteopontin and survival in non-small-cell lung cancer patients: a meta-analysis of 13 cohorts

In the last decade, osteopontin (OPN) was identified as one of the important proteins that promote the metastasis of tumor. However, the association between OPN overexpression and clinical outcome of non-small-cell lung cancer (NSCLC) was unclear. The purpose of this study is to investigate the role of OPN in NSCLC patients. A total of 13 studies are included to explore the relationship between the OPN elevation and the overall survival (OS) and disease-free survival (DFS) in NSCLC patients. We searched for related articles in PubMed, Web of Science, Google Scholar, and Cochrane Library databases, which were published before January 31, 2015. Hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) in the high OPN expression group compared with the low OPN expression group were calculated and analyzed. Primary results were summarized by using a fixed-effects model or a random-effects model. The stratified analyses in subgroups were also performed. Thirteen cohort studies, which involved 1,630 patients, were included. Subgroup analyses were performed by area and test method of OPN. We found that OPN was significantly associated with poor OS (HR =2.20, 95% CI 1.71–2.83, P<0.001) and DFS (HR =2.11, 95% CI 1.62–2.74, P<0.001) in NSCLC patients. OPN overexpression tended to be associated with the presence of advanced tumor TNM stage (III and IV) (OR =2.57, 95% CI 1.61–4.11, P<0.001). The Egger’s test suggested that there was no publication bias in OS studies (P=0.062) and DFS studies (P=0.740). These data indicate that OPN seems to have a significant predictive potential in estimating survival in NSCLC.

Is there any correlation between levels of serum ostepontin, CEA, and FDG uptake in lung cancer patients with bone metastasis?

OBJECTIVE

In this study, an evaluation was made of the relationship between the serum levels of carcinoembryonic antigen (CEA), osteopontin (OPN), and the semi-quantitative parameters of 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in lung cancer patients with bone metastasis.

MATERIAL AND METHODS

The evaluation included 42 non-small cell lung cancer (NSCLC) and 31 small cell lung cancer (SCLC) patients who were referred to our institution for staging by (18)F-FDG PET/CT. The biochemical parameters measured included CEA and OPN serum levels.

RESULTS

Serum levels of OPN in NSCLC patients with and without bone metastasis were 21.20±4.97 ng/ml and 13.33±4.53 ng/ml, respectively (p<0.05). In SCLC patients with and without bone metastasis serum OPN levels were 23.95±4.78 ng/ml and 17.30±3.09 ng/ml, respectively (p<0.05). Serum levels of CEA in NSCLC patients with and without bone metastasis were 33.79±6.49 ng/ml and 11.74±2.96 ng/ml, respectively (p<0.05). In SCLC patients with and without bone metastasis serum levels of CEA were 28.93±4.59 ng/ml and 13.88±4.47 ng/ml, respectively (p<0.05). There were no correlations between primary tumor SUVmax, and serum levels of CEA and OPN.

CONCLUSIONS

Bone metastasis can be detected in patients with lung cancer by measuring CEA and OPN levels. Increased levels of CEA and OPN levels may be considered an early warning sign in patients needing accurate imaging, as they are at higher risk of bone metastasis.

Prognostic significance of osteopontin in patients with non-small cell lung cancer: results from a meta-analysis

BACKGROUNDS

Non-small cell lung cancer (NSCLC) is one of the most common malignancies with a high mortality level. Recently, a variety of studies explored the role of osteopontin (OPN) expression in the prognosis of NSCLC, but the results were controversial.

METHODS

We performed a meta-analysis of eligible studies to evaluate the prognostic significance of OPN expression in NSCLC patients. In order to assess the association between OPN and OS and DFS/PFS, hazard ratio (HR) with 95% confidence interval (CI) was calculated.

RESULTS

A total of ten studies comprising 1420 patients were included in the meta-analysis. The summary results indicated that high OPN expression was a poor predictor for OS (HR = 2.19, 95% CI: 1.6-2.98), and DFS/PFS (HR = 2, 95% CI: 1.66-2.41). Subgroup analysis revealed that high OPN expression was a negative prognostic marker for OS and DFS/PFS regardless of ethnicity background, treatment and OPN detection method.

CONCLUSION

Our results showed that increased OPN expression significantly correlated with poor OS and DPS/PFS in NSCLC patients.

Clinical and prognostic significance of OPN and VEGF expression in patients with non-small-cell lung cancer

BACKGROUND

Osteopontin (OPN) and vascular endothelial growth factor (VEGF) play important roles in cancer progression and angiogenesis. In the current study we aimed to investigate the clinical significance of OPN and VEGF expression in patients with non-small-cell lung cancer (NSCLC) and to investigate their prognostic value for NSCLC.

METHODS

Immunohistochemical staining was used to detect the expression of OPN and VEGF in 146 NSCLC patients undergoing surgical resection in our hospital between 2006 and 2008. The associations between OPN and VEGF expression and clinicopathological data were analyzed using chi-square test analysis. Survival analysis was performed using the Kaplan-Meier method. The prognostic values of OPN and VEGF were evaluated by univariate and multivariate Cox proportional hazard model analysis.

RESULTS

OPN and VEGF expression was positive in 94 and 86 out of 146 NSCLC specimens, respectively. OPN expression was significantly associated with gender (P=0.002), TNM stage (P<0.001) and tumor differentiation (P=0.008). VEGF expression was significantly associated with TNM stage (P=0.015), tumor differentiation (P=0.032) and lymph-node status (P<0.001). There was a significant correlation between OPN and VEGF expression (P=0.035). Survival analysis indicated that OPN(+)/VEGF(+) patients had the worst prognosis. Furthermore, univariate and multivariate analysis suggested that tumor stage, lymph-node metastases, OPN expression and VEGF expression were independent prognostic factors for NSCLC.

CONCLUSION

The data suggest that OPN and VEGF expressions could serve as prognostic factors for NSCLC.

Evaluation of serum osteopontin level and gene polymorphism as biomarkers: analyses from the Nordic Adjuvant Interferon alpha Melanoma trial

Malignant melanoma is highly aggressive cancer with poor prognosis and few therapeutic options. Interferon alpha (IFN-α) has been tested as adjuvant immunotherapy in high-risk melanoma patients in a number of studies, but its beneficial role is controversial. Although IFN-α treatment can prolong relapse-free survival, the effect on overall survival is not significant. However, a small subset of patients benefits from the treatment, signifying the need for biomarkers able to identify a responding subgroup. Here we evaluated whether serum osteopontin (OPN) could function as a biomarker identifying patients with poor prognosis that might benefit from IFN-α. The choice of osteopontin was based on the knowledge about the dual role of this protein in cancer and immune response, an apparent association between OPN and IFN signaling and a prognostic value of OPN in multiple other tumor types. Serum samples from 275 high-risk melanoma patients enrolled in the Nordic Adjuvant IFN Melanoma trial were analyzed for circulating OPN concentrations and OPN promoter polymorphisms in position -443. The potential relation between serum OPN levels, the genotypes and survival in non-treated patients and patients receiving adjuvant IFN-α was investigated. Although slightly better survival was observed in the treated patients that had high levels of OPN, the difference was not statistically significant. In conclusion, serum OPN (its level or the genotype) cannot distinguish melanoma patients with poor prognosis, or patients that might benefit from adjuvant treatment with IFN-α.

The role of osteopontin expression in melanoma progression

It was shown that osteopontin (OPN), a glycophosphoprotein, plays divergent roles in cancer progression. In addition to multiple intra- and extracellular functions, it facilitates migration of tumour cells, has crucial role in cell adhesion and is associated with increased metastasis formation. In previous studies, we performed global gene expression profiling on a series of primary melanoma samples and found that OPN was significantly overexpressed in ulcerated melanomas. The major purpose of this study was to define OPN expression in primary melanomas with differing biological behaviours. OPN mRNA expression was analysed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in primary melanoma tissues. Immunohistochemistry was performed using a tissue microarray. Cox regression tests were used for survival analysis. Greater than 50 % of the tissues exhibited high protein expression that was significantly associated with tumour thickness and metastasis. OPN mRNA expression was significantly increased in thicker melanomas and lesions with an ulcerated surface. Increased expression was primarily detected in advanced-stage tumours. A multivariate Cox regression analysis revealed that high OPN expression, tumour thickness and metastasis were significantly associated with reduced relapse-free survival. In summary, high OPN mRNA and protein expression were associated with a less favourable clinical outcome of primary melanoma patients. We determined that OPN is a significant predictive factor for the survival of primary melanoma patients. Based on our and others data, the high expression of OPN may have a crucial stimulatory role in tumour progression and metastasis formation, which, thus, have been proposed as potential targets for cancer diagnosis and therapy.

Prognostic significance of osteopontin in patients with lung cancer: a meta-analysis

Both plasma/serum/pleural effusion osteopontin concentration (PSPO) and tumor tissue osteopontin expression (TTO) have recently been reported to be involved in the prognosis of lung cancer. In this study, we performed a meta-analysis to demonstrate the association between PSPO/TTO and survival in patients with lung cancer. We searched in PubMed, EMBASE, Cochrane library, Web of Science and Chinese Biomedical database (CBM) for relevant literatures. Stata 12.0 was applied to pool the eligible studies and synthesize hazard ratios (HRs) and its corresponding 95% confidence interval (CI). For PSPO, a total of 8 studies with 1000 patients were included in final analysis. Combined HR suggested high PSPO predicted an unfavorable overall survival (OS) (HR=1.52, 95% CI: 1.13-2.05) and progress-free survival (PFS) (HR=1.73, 95% CI: 1.35-2.21). For TTO, 5 studies with a total of 747 patients were employed in final analysis. Pooled HR indicated that elevated TTO was associated with poor OS (HR=2.16, 95% CI: 1.65-2.83) and disease/relapse-free survival (D/RFS) (HR=2.36, 95% CI: 1.79-3.12). Subgroup analysis was performed to explore the causes of heterogeneity. Publication bias by begg's test was not statistically significant. Sensitivity analysis showed that the pooled results were robust. This study revealed that both high TTO and PSPO are associated with poor prognosis in patients with lung cancer.

Aberrant expression of osteopontin and E-cadherin indicates radiation resistance and poor prognosis for patients with cervical carcinoma

Radiotherapy is the first-line treatment for all stages of cervical cancer, whether it is used for radical or palliative therapy. However, radioresistance of cervical cancer remains a major therapeutic problem. Consequently, we explored if E-cadherin (a marker of epithelial-mesenchymal transition) and osteopontin could predict radioresistance in patients with locally advanced cervical squamous cell carcinoma (LACSCC). Patients were retrospectively reviewed and 111 patients divided into two groups (radiation-resistant and radiation-sensitive groups) according to progression-free survival (PFS). In pretreated paraffin-embedded tissues, we evaluated E-cadherin and osteopontin expression using immunohistochemical staining. The percentage of patients with high osteopontin but low E-cadherin expression in the radiation-resistant group was significantly higher than those in the radiation-sensitive group (p<0.001). These patients also had a lower 5-year PFS rate (p<0.001). Our research suggests that high osteopontin but low E-cadherin expression can be considered as a negative, independent prognostic factor in patients with LACSCC ([Hazard ratios (95% CI) 6.766 (2.940, 15.572)], p<0.001).

Association of osteopontin expression with the prognosis of glioma patient: a meta-analysis

So far, several studies on the association between osteopontin (OPN) expression and glioma have been performed, but the conclusion still was not clear. The aim of the present meta-analysis was to determine the relationship between OPN expression and prognosis of patients with glioma. The electronic database was searched for articles on the association between OPN expression and glioma until 31 January 2014. Odds ratios (OR) and the relative risks with 95 % CI were utilized to analyze the qualitative data in retrospective studies and prospective studies, respectively. The standardized mean difference and the corresponding 95 % CI were used for analyzing the studies with quantitative data. Heterogeneity of all included studies was assessed using Cochrane's Q test and I (2) measurement. The publication bias was examined by the Egger test. Sixteen cohort studies (854 patients) on OPN expression and gliomas prognosis were included in the present meta-analysis. It was found that OPN expression was significantly higher in patients with high-grade glioma than in patients with low-grade glioma (χ (2) = 8.38, I (2)  = 16.6 %, P = 0.300), and the expression of OPN increased with glioma grade. The combined data showed the correlation between high OPN expression and tumor reoccurrence (OR = 18.61, 95 % CI = 6.34-54.67, P = 0.405). In addition, the results of the pooled analysis indicated that OPN expression was significantly related to overall survival (HR = 1.83; 95 % CI = 1.36-2.46). In conclusion, OPN may be a biomarker for predicting the prognosis of gliomas.

Genetic association of osteopontin (OPN) and its receptor CD44 genes with susceptibility to Chinese gastric cancer patients

PURPOSE

(1) To investigate associations between single nucleotide polymorphisms (SNPs) in osteopontin (OPN) and its receptor-cluster of differentiation 44 (CD44) genes and gastric cancer susceptibility. (2) To explore the correlation of OPN and CD44 expression of gastric cancer.

METHODS

We detected 26 SNPs of the genes in gastric cancer patients from the Chinese Han population by Sequenom technique and performed expression of OPN in combination with CD44 in 243 tissues samples of the cases by tissue microarray and immunohistochemistry (IHC).

RESULTS

We found that the minor alleles of OPN rs4754C>T and OPN rs9138C>A remained strongly associated with decreased gastric cancer risk (P = 1.53 × 10(-4), odds ratio (OR) 0.642, 95 % confidence interval (CI) 0.511-0.808 and P = 1.59 × 10(-4), OR 0.642, 95 %CI 0.510-0.809). OPN variant rs1126772A>G and CD44 variant rs353639A>C significantly contributed to elevated risk of gastric cancer (P = 0.042, OR 1.279, 95 % CI 1.008-1.622 and P = 0.047, OR 1.334, 95 % CI 1.003-1.772). Haplotypes of OPN and CD44 variants significantly influenced risk of gastric cancer. Clinical data indicated that rs4754 and rs9138 of OPN were significantly associated with smoking (P = 0.029, OR 0.343, 95 % CI 0.127-0.926 and P = 0.029, OR 0.343, 95 %CI 0.127-0.926) and OPN rs1126772 revealed associations with tumor-node-metastasis (TNM) stage (P = 0.025, OR 1.765, 95 % CI 1.073-2.905) and tumor differentiation (P = 0.031, OR 1.722, 95 % CI 1.049-2.825). OPN expression was observed in 133 of the 243 cases (54.7 %) by IHC and was correlated with serosa invasion (P = 0.013), TNM stage (P = 0.003) and lymph node metastasis (P = 0.002). CD44 expression was found in 92 of the 243 cases (37.9 %) and was associated with tumor size (P = 0.005) and lymph node metastasis (P = 0.023), respectively. The OPN expression displayed a positive association with CD44 (P = 0.01, r s = 0.164).

CONCLUSIONS

We found that the polymorphisms rs4754, rs9138 and rs1126772 of OPN gene and rs353639 of CD44 gene were significantly associated with gastric cancer. Our IHC data indicated that interaction of OPN and CD44 protein would promote progression and metastasis of gastric cancer.

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.

Diagnostic significance of serum osteopontin level for pancreatic cancer: a meta-analysis

OBJECTIVE

This meta-analysis aimed to identify the significance of serum osteopontin (OPN) level for the diagnosis of pancreatic cancer (PC).

METHODS

Through searching the following electronic databases-the Cochrane Library Database (Issue 12, 2013), Web of Science (1945-2013), PubMed (1966-2013), CINAHL (1982-2013), EMBASE (1980-2013), and the Chinese Biomedical Database (CBM) (1982-2013)-related articles were determined without any language restrictions. The STATA statistical software (version 12.0; Stata Corporation, College Station, TX) was chosen to deal with statistical data. Standard mean difference (SMD) and its corresponding 95% confidence interval (95% CI) was calculated. Eleven clinical case-control studies, which recruited 491 PC patients and 481 healthy controls, were selected for statistical analysis.

RESULTS

Combined SMD of OPN suggested that the serum OPN level in PC patients was significantly higher than that in healthy controls (SMD=3.58, 95% CI=2.42-4.74, p<0.001). Ethnicity stratified analysis indicated a higher serum OPN level in PC patients compared with control subjects among both Caucasians and Asians (Caucasians: SMD=2.62, 95% CI=1.33-3.91, p<0.001; Asians: SMD=4.54, 95% CI=2.80-6.27, p<0.001; respectively).

CONCLUSION

The main finding of our meta-analysis revealed that an elevated serum OPN level may be used as a promising diagnostic tool for early identification of PC.

The prognostic value of osteopontin expression in non-small cell lung cancer: a meta-analysis

To investigate the association of Osteopontin (OPN) expression in tumor tissue with clinicopathological features of non-small cell lung carcinoma (NSCLC) patients. Publications assessing the clinicopathological characteristics and prognostic significance of OPN in expression NSCLC were identified up to March 2014. A meta-analysis of eligible studies was performed using standard statistical methods to clarify the association between OPN expression and these clinical parameters. A total of eleven studies met the inclusion criteria, and included 1536 cases of NSCLC tumor tissue and 340 cases of normal lung tissue. The OPN expression rate in NSCLC tissue was higher than normal tissue [Odds ratio (OR) 6.427; 95% confidence interval (CI) 4.689-8.808; P = 0.000]. Simultaneously, we also found that OPN expression was positively associated with stage (OR 0.332; 95% CI 0.250-0.440; P = 0.000), lymph node metastasis (OR 3.094; 95% CI 2.295-4.172; P = 0.000), tumor size (tumor size <3 cm vs. ≥3 cm; OR 0.484; 95% CI 0.303-0.773; P = 0.002) and pathology (OR 0.611; 95% CI 0.466-0.800; P = 0.000). It was unrelated that OPN expression in NSCLC tissue with and degree of differentiation and other clinical features (P > 0.05). Experimental findings indicate that, OPN plays a crucial role in the development of NSCLC.