Correlation of osteopontin protein expression and pathological stage across a wide variety of tumor histologies

Unlocking the potential of oncology biomarkers: advancements in clinical theranostics

INTRODUCTION

Cancer biomarkers have revolutionized the field of oncology by providing valuable insights into tumor changes and aiding in screening, diagnosis, prognosis, treatment prediction, and risk assessment. The emergence of "omic" technologies has enabled biomarkers to become reliable and accurate predictors of outcomes during cancer treatment.

CONTENT

In this review, we highlight the clinical utility of biomarkers in cancer identification and motivate researchers to establish a personalized/precision approach in oncology. By extending a multidisciplinary technology-based approach, biomarkers offer an alternative to traditional techniques, fulfilling the goal of cancer therapeutics to find a needle in a haystack.

SUMMARY AND OUTLOOK

We target different forms of cancer to establish a dynamic role of biomarkers in understanding the spectrum of malignancies and their biochemical and molecular characterization, emphasizing their prospective contribution to cancer screening. Biomarkers offer a promising avenue for the early detection of human cancers and the exploration of novel technologies to predict disease severity, facilitating maximum survival and minimum mortality rates. This review provides a comprehensive overview of the potential of biomarkers in oncology and highlights their prospects in advancing cancer diagnosis and treatment.

Fenofibrate suppresses the progression of hepatoma by downregulating osteopontin through inhibiting the PI3K/AKT/Twist pathway

Primary hepatic carcinoma (PHC) is a leading threat to cancer patients with few effective treatment strategies. OPN is found to be an oncogene in hepatocellular carcinoma (HCC) with potential as a treating target for PHC. Fenofibrate is a lipid-lowering drug with potential anti-tumor properties, which is claimed with suppressive effects on OPN expression. Our study proposes to explore the molecular mechanism of fenofibrate in inhibiting HCC. OPN was found extremely upregulated in 6 HCC cell lines, especially Hep3B cells. Hep3B and Huh7 cells were treated with 75 and 100 μM fenofibrate, while OPN-overexpressed Hep3B cells were treated with 100 μM fenofibrate. Decreased clone number, elevated apoptotic rate, reduced number of migrated cells, and shortened migration distance were observed in fenofibrate-treated Hep3B and Huh7 cells, which were markedly abolished by the overexpression of OPN. Furthermore, the facilitating effect against apoptosis and the inhibitory effect against migration of fenofibrate in Hep3B cells were abolished by 740 Y-P, an agonist of PI3K. Hep3B xenograft model was established, followed by treated with 100 mg/kg and 200 mg/kg fenofibrate, while OPN-overexpressed Hep3B xenograft was treated with 200 mg/kg fenofibrate. The tumor growth was repressed by fenofibrate, which was notably abolished by OPN overexpression. Furthermore, the inhibitory effect of fenofibrate on the PI3K/AKT/Twist pathway in Hep3B cells and Hep3B xenograft model was abrogated by OPN overexpression. Collectively, fenofibrate suppressed progression of hepatoma downregulating OPN through inhibiting the PI3K/AKT/Twist pathway.

Osteopontin: an essential regulatory protein in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic lung disease characterized by abnormal proliferation and activation of fibroblasts, excessive accumulation of extracellular matrix (ECM), inflammatory damage, and disrupted alveolar structure. Despite its increasing morbidity and mortality rates, effective clinical treatments for IPF remain elusive. Osteopontin (OPN), a multifunctional ECM protein found in various tissues, has been implicated in numerous biological processes such as bone remodeling, innate immunity, acute and chronic inflammation, and cancer. Recent studies have highlighted the pivotal role of OPN in the pathogenesis of IPF. This review aims to delve into the involvement of OPN in the inflammatory response, ECM deposition, and epithelial-mesenchymal transition (EMT) during IPF, and intends to lay a solid theoretical groundwork for the development of therapeutic strategies for IPF.

Osteopontin in cancer

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

Lipid polymer hybrid nanoparticles: a custom-tailored next-generation approach for cancer therapeutics

Lipid-based polymeric nanoparticles are the highly popular carrier systems for cancer drug therapy. But presently, detailed investigations have revealed their flaws as drug delivery carriers. Lipid polymer hybrid nanoparticles (LPHNPs) are advanced core-shell nanoconstructs with a polymeric core region enclosed by a lipidic layer, presumed to be derived from both liposomes and polymeric nanounits. This unique concept is of utmost importance as a combinable drug delivery platform in oncology due to its dual structured character. To add advantage and restrict one's limitation by other, LPHNPs have been designed so to gain number of advantages such as stability, high loading of cargo, increased biocompatibility, rate-limiting controlled release, and elevated drug half-lives as well as therapeutic effectiveness while minimizing their drawbacks. The outer shell, in particular, can be functionalized in a variety of ways with stimuli-responsive moieties and ligands to provide intelligent holding and for active targeting of antineoplastic medicines, transport of genes, and theragnostic. This review comprehensively provides insight into recent substantial advancements in developing strategies for treating various cancer using LPHNPs. The bioactivity assessment factors have also been highlighted with a discussion of LPHNPs future clinical prospects.

What is new in cancer-associated fibroblast biomarkers?

The tumor microenvironment is one of the important drivers of tumor development. Cancer-associated fibroblasts (CAFs) are a major component of the tumor stroma and actively participate in tumor development, invasion, metastasis, drug resistance, and other biological behaviors. CAFs are a highly heterogeneous group of cells, a reflection of the diversity of their origin, biomarkers, and functions. The diversity of CAF origin determines the complexity of CAF biomarkers, and CAF subpopulations expressing different biomarkers may play contrasting roles in tumor progression. In this review, we provide an overview of these emerging CAF biomarkers and the biological functions that they suggest, which may give a better understanding of the relationship between CAFs and tumor cells and be of great significance for breakthroughs in precision targeted therapy for tumors. Video Abstract.

Multianalyte Serum Biomarker Panel for Early Detection of Pancreatic Adenocarcinoma

PURPOSE

We determined whether a large, multianalyte panel of circulating biomarkers can improve detection of early-stage pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

We defined a biologically relevant subspace of blood analytes on the basis of previous identification in premalignant lesions or early-stage PDAC and evaluated each in pilot studies. The 31 analytes that met minimum diagnostic accuracy were measured in serum of 837 subjects (461 healthy, 194 benign pancreatic disease, and 182 early-stage PDAC). We used machine learning to develop classification algorithms using the relationship between subjects on the basis of their changes across the predictors. Model performance was subsequently evaluated in an independent validation data set from 186 additional subjects.

RESULTS

A classification model was trained on 669 subjects (358 healthy, 159 benign, and 152 early-stage PDAC). Model evaluation on a hold-out test set of 168 subjects (103 healthy, 35 benign, and 30 early-stage PDAC) yielded an area under the receiver operating characteristic curve (AUC) of 0.920 for classification of PDAC from non-PDAC (benign and healthy controls) and an AUC of 0.944 for PDAC versus healthy controls. The algorithm was then validated in 146 subsequent cases presenting with pancreatic disease (73 benign pancreatic disease and 73 early- and late-stage PDAC cases) and 40 healthy control subjects. The validation set yielded an AUC of 0.919 for classification of PDAC from non-PDAC and an AUC of 0.925 for PDAC versus healthy controls.

CONCLUSION

Individually weak serum biomarkers can be combined into a strong classification algorithm to develop a blood test to identify patients who may benefit from further testing.

Osteopontin and Ki-67 expression in World Health Organization graded canine meningioma

Osteopontin (OPN) is a matrix protein involved in tumour initiation and progression. In human meningioma, OPN has been correlated with World Health Organization (WHO) grade, brain invasion and recurrence. The aim of this study was to investigate OPN as a possible malignancy marker in canine meningioma by correlating its expression to WHO grade and proliferative activity as measured by the Ki-67 labelling index (LI). Thirty-five formalin-fixed, paraffin-embedded canine meningioma samples were classified according to the current human WHO classification. Evaluation of OPN expression was performed by immunohistochemical (IHC) labelling and calculation of the OPN intensity score (IS), OPN IHC score and Allred score. The scores were compared with WHO grades, Ki-67 LI, location and invasiveness. Nineteen meningiomas were graded as WHO grade I (54.3%), nine as grade II (25.7%) and seven as grade III (20.0%). Twenty-six tumours were located intracranially, four were retrobulbar and five were spinal meningiomas. In all specimens OPN expression was detected in moderate to high degrees. Neither the OPN scores nor the Ki-67 LIs were correlated with WHO grades. However, the OPN IS and OPN IHC score were significantly higher in WHO grade I samples compared with grade II samples (P <0.05). The OPN IS and OPN IHC score were significantly lower in meningioma samples that invaded surrounding tissues (P = 0.01 and 0.019, respectively). The results indicate a generally high expression of OPN in canine meningioma independent of WHO grade. Further research into the role of OPN as a possible therapeutic target or predictor of recurrence is warranted.

Cytokine profiling in plasma distinguishes the histological inflammatory subtype of head and neck squamous cell carcinoma and a novel regulatory role of osteopontin

Head and neck squamous cell carcinoma (HNSCC) can be classified according to the histological inflammatory subtype (HIS) into inflamed (HIS-INF) or immune excluded (HIS-IE). HIS-IE was previously associated with higher levels of soluble Semaphorin 4D (HsS4D) in plasma, and higher transcriptional levels of osteopontin (OPN) in the tumor tissue, compared to HIS-INF. The goal of the current study is to investigate whether the HIS inflammatory subtype can be distinguished by a differential cytokine panel in peripheral blood. Retrospectively collected five HIS-INF and five HIS-IE tumor tissue with paired plasma were included in the study. Five healthy donors (HD) and five autoimmune/chronic inflammatory conditions (AI/CI) were controls. The ELISA-Luminex™ system was used to detect 40 traditional cytokines in plasma. Human cytokine array (104 cytokines) was used for the conditioned medium (CM) of the HNSCC HN6 cell line. Semaphorin 4D (Sema4D) siRNA and recombinant human osteopontin (rh-OPN) were used to investigate the effect of OPN on Sema4D expression. The HIS-IE cytokine profile was higher than HIS-INF but comparable to AI/CI. HIS-INF had the lowest cytokine levels. HIS-IE was differentially higher in IP-10 and IL8 compared to HD, while HIS-INF was higher in IL-10. Sema4D inhibition in HN6 resulted in a decrease of OPN in the CM of HN6, and treatment with rh-OPN rescued Sema4D in HN6 cell lysate and associated CM. In conclusion, the current work demonstrates a novel association between the HIS subtypes and a differential pattern of cytokine expression in plasma. These findings can open new avenues for HNSCC patient stratification and hence provide better personalized treatment.

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.

Dysregulated Expression of Three Genes in Colorectal Cancer Stratifies Patients into Three Risk Groups

Despite advances in recent years in the study of the molecular profile of sporadic colorectal cancer (sCRC), the specific genetic events that lead to increased aggressiveness or the development of the metastatic process of tumours are not yet clear. In previous studies of the gene expression profile (GEP) using a high-density array (50,000 genes and 6000 miRNAs in a single assay) in sCRC tumours, we identified a 28-gene signature that was found to be associated with an adverse prognostic value for predicting patient survival. Here, we analyse the differential expression of these 28 genes for their possible association with tumour local aggressiveness and metastatic processes in 66 consecutive sCRC patients, followed for >5 years, using the NanoString nCounter platform. The global transcription profile (expression levels of the 28 genes studied simultaneously) allowed us to discriminate between sCRC tumours and nontumoral colonic tissues. Analysis of the biological and functional significance of the dysregulated GEPs observed in our sCRC tumours revealed 31 significantly altered canonical pathways. Among the most commonly altered pathways, we observed the increased expression of genes involved in signalling pathways and cellular processes, such as the PI3K-Akt pathway, the interaction with the extracellular matrix (ECM), and other functions related to cell signalling processes (SRPX2). From a prognostic viewpoint, the altered expression of BST2 and SRPX2 genes were the only independent variables predicting for disease-free survival (DFS). In addition to the pT stage at diagnosis, dysregulated transcripts of ADH1B, BST2, and FER1L4 genes showed a prognostic impact on OS in the multivariate analysis. Based on the altered expression of these three genes, a scoring system was built to stratify patients into low-, intermediate-, and high-risk groups with significantly different 5-year OS rates: 91%, 83%, and 52%, respectively. The prognostic impact was validated in two independent series of sCRC patients from the public GEO database (n = 562 patients). In summary, we show a strong association between the altered expression of three genes and the clinical outcome of sCRC patients, making them potential markers of suitability for adjuvant therapy after complete tumour resection. Additional prospective studies in larger series of patients are required to confirm the clinical utility of the newly identified biomarkers because the number of patients analysed remains small.

Alpha-smooth muscle actin-positive cancer-associated fibroblasts secreting osteopontin promote growth of luminal breast cancer

Background

Cancer-associated fibroblasts (CAFs) have been shown to support tumor development in a variety of cancers. Different markers were applied to classify CAFs in order to elucidate their impact on tumor progression. However, the exact mechanism by which CAFs enhance cancer development and metastasis is yet unknown.

Methods

Alpha-smooth muscle actin (α-SMA) was examined immunohistochemically in intratumoral CAFs of nonmetastatic breast cancers and correlated with clinicopathological data. Four CAF cell lines were isolated from patients with luminal breast cancer (lumBC) and classified according to the presence of α-SMA protein. Conditioned medium (CM) from CAF cultures was used to assess the influence of CAFs on lumBC cell lines: MCF7 and T47D cells using Matrigel 3D culture assay. To identify potential factors accounting for promotion of tumor growth by α-SMA^high CAFs, nCounter PanCancer Immune Profiling Panel (NanoString) was used.

Results

In luminal breast cancer, presence of intratumoral CAFs expressing high level of α-SMA (13% of lumBC group) correlated with poor prognosis (p = 0.019). In in vitro conditions, conditioned medium obtained from primary cultures of α-SMA-positive CAFs isolated from luminal tumors was observed to enhance growth of lumBC cell line colonies in 3D Matrigel, in contrast to CM derived from α-SMA-negative CAFs. Multigene expression analysis indicated that osteopontin (OPN) was overexpressed in α-SMA-positive CAFs in both clinical samples and in vitro models. OPN expression was associated with higher percentage of Ki67-positive cells in clinical material (p = 0.012), while OPN blocking in α-SMA-positive CAF-derived CM attenuated growth of lumBC cell line colonies in 3D Matrigel.

Conclusions

Our findings demonstrate that α-SMA-positive CAFs might enhance tumor growth via secretion of OPN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00351-7.

The Role of Extracellular Matrix Proteins in Breast Cancer

The extracellular matrix is a structure composed of many molecules, including fibrillar (types I, II, III, V, XI, XXIV, XXVII) and non-fibrillar collagens (mainly basement membrane collagens: types IV, VIII, X), non-collagenous glycoproteins (elastin, laminin, fibronectin, thrombospondin, tenascin, osteopontin, osteonectin, entactin, periostin) embedded in a gel of negatively charged water-retaining glycosaminoglycans (GAGs) such as non-sulfated hyaluronic acid (HA) and sulfated GAGs which are linked to a core protein to form proteoglycans (PGs). This highly dynamic molecular network provides critical biochemical and biomechanical cues that mediate the cell–cell and cell–matrix interactions, influence cell growth, migration and differentiation and serve as a reservoir of cytokines and growth factors’ action. The breakdown of normal ECM and its replacement with tumor ECM modulate the tumor microenvironment (TME) composition and is an essential part of tumorigenesis and metastasis, acting as key driver for malignant progression. Abnormal ECM also deregulate behavior of stromal cells as well as facilitating tumor-associated angiogenesis and inflammation. Thus, the tumor matrix modulates each of the classically defined hallmarks of cancer promoting the growth, survival and invasion of the cancer. Moreover, various ECM-derived components modulate the immune response affecting T cells, tumor-associated macrophages (TAM), dendritic cells and cancer-associated fibroblasts (CAF). This review article considers the role that extracellular matrix play in breast cancer. Determining the detailed connections between the ECM and cellular processes has helped to identify novel disease markers and therapeutic targets.

Aptamer grafted nanoparticle as targeted therapeutic tool for the treatment of breast cancer

Breast carcinomas repeat their number and grow exponentially making it extremely frequent malignancy among women. Approximately, 70-80% of early diagnosed or non-metastatic conditions are treatable while the metastatic cases are considered ineffective to treat with current ample amount of therapy. Target based anti-cancer treatment has been in the limelight for decades and is perceived significant consideration of scientists. Aptamers are the 'coming of age' therapeutic approach, selected using an appropriate tool from the library of sequences. Aptamers are non-immunogenic, stable, and high-affinity ligand which are poised to reach the clinical benchmark. With the heed in nanoparticle application, the delivery of aptamer to the specific site could be enhanced which also protects them from nuclease degradation. Moreover, nanoparticles due to robust structure, high drug entrapment, and modifiable release of cargo could serve as a successful candidate in the treatment of breast carcinoma. This review would showcase the method and modified method of selection of aptamers, aptamers that were able to make its way towards clinical trial and their targetability and selectivity towards breast cancers. The appropriate usage of aptamer-based biosensor in breast cancer diagnosis have also been discussed.

The role of SPP1 as a prognostic biomarker and therapeutic target in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies and has a low 5-year survival rate. Mounting evidence suggests that oral potentially malignant disorders, such as oral leukoplakia (OLK), may progress to HNSCC. Given that OLK and HNSCC are often insidious and asymptomatic, the identification of markers of OLK malignant transformation and therapeutic targets in HNSCC is critical. Using various online tools and publicly available gene expression datasets, the secreted phosphoprotein 1 gene (SPP1) was identified as a significant differentially expressed gene among OLK, HNSCC, and non-cancerous tissues. SPP1 mRNA levels were elevated in HNSCC tissues and were associated with cancer stage, tumor grade, and human papillomavirus infection status. High SPP1 mRNA levels were correlated with poor overall survival of HNSCC patients. In contrast, SPP1 mutations were not significantly associated with overall survival, although their frequency in HNSCC was very low (0.6%). Furthermore, SPP1 expression levels in HNSCC were positively correlated with the infiltration of CD4⁺ cells, macrophages, neutrophils, and dendritic cells. The study results suggest that SPP1 may represent a diagnostic and prognostic biomarker, as well as a potential therapeutic target in HNSCC.

Osteopontin, GLUT1 and Ki-67 expression in malignant peritoneal mesothelioma: prognostic implications

Background

Malignant peritoneal mesothelioma is the most common primary peritoneal neoplasm. The only universally recognised pathological prognostic factor is histopathological subtype. Prognostic markers based on patient features and clinical stages have been disappointing.

Aims

To assess the prognostic role of several clinicopathological features in a retrospective cohort of 60 patients diagnosed with peritoneal mesothelioma.

Methods

Sixty patients were centrally collected and were immunohistochemically analysed for the expression of osteopontin (OPN), GLUT1 and Ki‐67. Labelling was assessed by two pathologists. Complete clinical information and follow‐up were obtained from patients' records.

Results

OPN expression was identified in 52 (86.6%) of 60 specimens, and GLUT1 in 39 (65%) of 60 specimens. Univariate Cox regression analysis showed that a lower peritoneal carcinomatosis index (PCI), tumour‐directed treatment (chemotherapy or surgery alone or in any combination), lower Ki‐67, GLUT1 and lower OPN expression had a statistically significant positive effect on overall survival (OS). PCI (hazard ratio (HR) = 1.032 (95% confidence interval (CI): 1.000–1.067); P = 0.054) and tumour‐directed treatment (HR = 0.211 (95% CI: 0.104–0.430); P < 0.001), Ki‐67 (HR = 22.326 (95% CI: 3.523–141.498); P = 0.003) and OPN (HR = 7.268 (95% CI: 1.771–29.811); P = 0.009) retained independent prognostic significance in the multivariate analysis, all with a positive effect on OS with the exception of GLUT1.

Conclusions

OPN, Ki‐67, treatment and PCI were independent indicators for OS, and a higher level of OPN expression correlated significantly with poorer OS.

Osteopontin as a Regulator of Colorectal Cancer Progression and Its Clinical Applications

Simple Summary

The mortality of colorectal cancer is principally related to metastatic disease at the time of diagnosis or to the growth of initially undetectable micro-metastasis. Current therapeutic strategies are efficient in patients with locally advanced cancer, but are rarely able to cure patients with metastatic disease. Therapeutic failure is mainly associated with drug resistance and an aggressive phenotype. The identification of new biomarkers for micro-metastasis and tumor progression remains an unmet clinical need that should allow for improved patient stratification for optimal treatment and may lead to the identification of novel therapeutic targets. Osteopontin (OPN), a multifunctional protein, has emerged as a potentially valuable biomarker in several cancer types. This review principally describes the molecular mechanisms of OPN that are associated with colorectal cancer (CRC) progression and metastasis, as well as the use of OPN as a clinical biomarker. This review identifies a role for OPN as a biomarker ready for extended clinical application and discusses its use as a therapeutic target.

Abstract

A high expression of the phosphoprotein osteopontin (OPN) has been associated with cancer progression in several tumor types, including breast cancer, hepatocarcinoma, ovarian cancer, and colorectal cancer (CRC). Interestingly, OPN is overexpressed in CRC and is associated with a poor prognosis linked to invasion and metastasis. Here, we review the regulation and functions of OPN with an emphasis on CRC. We examine how epigenetic and genetic regulators interact with the key signaling pathways involved in this disease. Then, we describe the role of OPN in cancer progression, including proliferation, survival, migration, invasion, and angiogenesis. Furthermore, we outline the interest of using OPN as a clinical biomarker, and discuss if and how osteopontin can be implemented as a routine assay in clinical laboratories for monitoring CRC patients. Finally, we discuss the use of OPN an attractive, but challenging, therapeutic target.

The Analysis of Inflammation-Related Proteins in a Cargo of Exosomes Derived from the Serum of Uveal Melanoma Patients Reveals Potential Biomarkers of Disease Progression

Simple Summary

Uveal melanoma (UM) is the most common intraocular tumour in adults with a poor prognosis and extremely high mortality rate due to the development of metastatic disease. Despite good knowledge of the histological and genetic background of metastases formation, there is still a lack of specific biomarkers which would allow early detection of UM progression. Due to their unique molecular cargo consisting of proteins and nucleic acids, exosomes have been widely studied as carriers of biomarkers for cancer development and progression. In this study, we analyzed the inflammation-related protein cargo of exosomes derived from the serum of primary and metastatic UM patients and healthy donors using multiplex immunoassay technology. We showed a significant correlation between the disease stage and the concentration of inflammation-related proteins from exosomal cargo. Based on the obtained results, we propose the panel of exosomal proteins for early detection of uveal melanoma progression into metastatic disease.

Abstract

Background: Uveal melanoma (UM) is the most common intraocular tumour in adults with a poor prognosis and extremely high mortality rate due to the development of metastatic disease. However, despite relatively good knowledge about the histological and genetic risk factors for metastasis development, there is no specific biomarker that would allow early detection of UM progression. Recently, exosomes and their molecular cargo have been widely studied in the search for potential biomarkers in several cancers. The purpose of this study was to analyze the inflammation-related protein cargo of exosomes derived from the serum of primary and metastatic UM patients and healthy donors. Methods: The exosomes were isolated from the serum of primary and metastatic UM patients and healthy donors. Using multiplex immunoassay technology, we analyzed the concentration of 37 inflammation-related proteins in obtained exosomes. Results: The analysis of protein cargo showed several molecules related to inflammation, such as interferon-gamma, interleukin 2, 22 and 12(p40), Pentraxin-3, TNFSF13B and TNFSF8 which were significantly enriched in metastatic UM exosomes. We showed a significant correlation between the disease stage and the concentration of these inflammation-related proteins from exosomal cargo. Conclusions: Based on the obtained results, we propose the panel of exosomal proteins for early detection of uveal melanoma progression into metastatic disease.

Evaluation of local and circulating osteopontin in malignant and benign primary bone tumors

Purpose

The development of novel and efficient biomarkers for primary bone cancers is of grave importance.

Methods

The expression pattern of osteopontin (OPN) was investigated in the 153 patients with benign (n = 72) and malignant (n = 81) primary bone cancers. Both local and circulating OPN mRNA expression levels and their protein concentration in serum and tumor site were assessed using real-time qRT-PCR, ELISA, and immunohistochemistry techniques, respectively. As a control, 29 healthy individuals were considered. The number of 153 tumor tissue specimens and the 153 paired margins were taken on surgical resection from the patients. 153 blood samples were also drained from all participants, then peripheral blood mononuclear cells (PBMC) and sera were separated.

Results

The mean mRNA expression was significantly higher in all of the cancerous tissues than the paired margins and the PBMC of the patients than the controls. Consistently, the protein concentrations of OPN in serum and tumor tissues were significantly higher in the patients. Furthermore, the malignant cases had significantly elevated the mRNA levels and the protein compared to the benign cases. OPN could potentially differentiate the patients from the controls with 100% sensitivity and specificity in serum. Moreover, OPN could predict some of the malignant cases' clinicopathological features, including metastasis, recurrence, grade, and response to chemotherapy.

Conclusions

In conclusion, OPN might be involved in the pathogenesis of primary bone tumors and can be considered as a potential biomarker to bone cancer diagnosis.

Osteopontin Blockade Immunotherapy Increases Cytotoxic T Lymphocyte Lytic Activity and Suppresses Colon Tumor Progression

Simple Summary

Despite the breakthrough in human cancer immunotherapy, colorectal cancer, except for the small subset of microsatellite instable colorectal cancer (MSI, ~4% total cases), is one of the few human cancers that does not respond to current immune checkpoint inhibitor (ICI) immunotherapy. CTLs are present in both MSI and microsatellite stable (MSS) human colon carcinoma, suggesting that PD-L1-independent mechanisms may exist and suppress CTL activation in the colon tumor microenvironment. We determined that osteopontin (OPN) inhibits tumor-specific cytotoxic T lymphocyte (CTL) lytic activity to promote colon tumor growth in vivo. Accordingly, OPN blockade immunotherapy using OPN neutralization monoclonal antibodies 100D3 and 103D6 suppressed colon tumor growth in vivo. Our findings indicate that 100D3 and 103D6 has the potential to be further developed for colorectal cancer immunotherapy.

Abstract

Human colorectal cancers are mostly microsatellite-stable with no response to anti-PD-1 blockade immunotherapy, necessitating the development of a new immunotherapy. Osteopontin (OPN) is elevated in human colorectal cancer and may function as an immune checkpoint. We aimed at elucidating the mechanism of action of OPN and determining the efficacy of OPN blockade immunotherapy in suppression of colon cancer. We report here that OPN is primarily expressed in tumor cells, myeloid cells, and innate lymphoid cells in human colorectal carcinoma. Spp1 knock out mice exhibit a high incidence and fast growth rate of carcinogen-induced tumors. Knocking out Spp1 in colon tumor cells increased tumor-specific CTL cytotoxicity in vitro and resulted in decreased tumor growth in vivo. The OPN protein level is elevated in the peripheral blood of tumor-bearing mice. We developed four OPN neutralization monoclonal antibodies based on their efficacy in blocking OPN inhibition of T cell activation. OPN clones 100D3 and 103D6 increased the efficacy of tumor-specific CTLs in killing colon tumor cells in vitro and suppressed colon tumor growth in tumor-bearing mice in vivo. Our data indicate that OPN blockade immunotherapy with 100D3 and 103D6 has great potential to be further developed for colorectal cancer immunotherapy and for rendering a colorectal cancer response to anti-PD-1 immunotherapy.

Bladder Tumor Subtype Commitment Occurs in Carcinoma In Situ Driven by Key Signaling Pathways Including ECM Remodeling

Basal and luminal subtypes of invasive bladder tumors have significant prognostic and predictive impacts for patients. However, it remains unclear whether tumor subtype commitment occurs in noninvasive urothelial lesions or in carcinoma in situ (CIS) and which gene pathways are important for bladder tumor progression. To understand the timing of this commitment, we used gene expression and protein analysis to create a global overview of 36 separate tissues excised from a whole bladder encompassing urothelium, noninvasive urothelial lesions, CIS, and invasive carcinomas. Additionally investigated were matched CIS, noninvasive urothelial lesions, and muscle-invasive bladder cancers (MIBC) from 22 patients. The final stage of subtype commitment to either a luminal or basal MIBC occurred at the CIS transition. For all tissues combined, hierarchical clustering of subtype gene expression revealed three subtypes: "luminal," "basal," and a "luminal p53-/extracellular matrix (ECM)-like" phenotype of ECM-related genes enriched in tumor-associated urothelium, noninvasive urothelial lesions, and CIS, but rarely invasive, carcinomas. A separate cohort of normal urothelium from noncancer patients showed significantly lower expression of ECM-related genes compared with tumor-associated urothelium, noninvasive urothelial lesions, and CIS. A PanCancer Progression Panel of 681 genes unveiled pathways specific for the luminal p53-/ECM-like cluster, for example, ECM remodeling, angiogenesis, epithelial-to-mesenchymal transition, cellular discohesion, cell motility involved in tumor progression, and cell proliferation and oncogenic ERBB2/ERBB3 signaling for invasive carcinomas. In conclusion, this study provides insights into bladder cancer subtype commitment and associated signaling pathways, which could help predict therapy response and enhance our understanding of therapy resistance. SIGNIFICANCE: This study demonstrates that CIS is the stage of commitment for determining MIBC tumor subtype, which is relevant for patient prognosis and therapy response.

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.

The role of osteopontin in oral cancer: A brief review with emphasis on clinical applications

Osteopontin (OPN) is a calcium-binding glycol-phosphoprotein present in many physiologic and pathological processes. This protein can control bone cell adhesion, osteoclastic activity, and bone matrix mineralization. However, its participation in pathological processes such as atherosclerosis, sarcoidosis, tuberculosis, and cancer have been described. Some studies have shown that OPN may participate in the development and progression of oral cancer. Although the role of OPN in oral cancer is not fully understood, some studies have suggested that this protein may induce malignant phenotype of cells by activation of PI3K/AKT/mTOR pathway, which favors cell proliferation, invasion, metastasis, angiogenesis, and failure of treatment. This review discusses the possible mechanism of involvement of OPN in oral cancer and its potential clinical application in diagnosis and prognosis.

Osteopontin level and promoter polymorphism in patients with metastatic breast cancer

Background

Cancer initiation typically occurs when a proto-oncogene's coding region undergoes mutation, resulting in uncontrollable cell growth and division, or when a tumour suppressor gene's coding region is affected by a mutation that inhibits activity of the resulting gene product. The pathophysiologic result is, respectively, exaggerated cell-cycle growth or deficient programmed cell death. Osteopontin (opn) is an integrin-binding phosphoprotein that is expressed on the surface of normal cells. Osteopontin has a major role in diverse tumour components, especially those implicated in invasion and metastasis. In the present study, we aimed to illustrate the value of opn as a possible contributor in breast cancer (bca).

Methods

This prospective study included 115 patients newly diagnosed with bca and distant metastasis who were recruited from the Oncology Center, Mansoura University, and the Department of Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Egypt. The patients recruited had been diagnosed with disseminated visceral metastasis (visceral crisis), with or without bone metastasis; patients with cranial metastasis were excluded from the study. All patients received first-line chemotherapy with docetaxel 75 mg/m2 plus cisplatin 75 mg/m2 or carboplatin 6 auc (area under the curve) on day 1 every 21 days for a maximum of 6 cycles or till development of toxicity. Trastuzumab (in cases of her2-positive disease) was given whenever possible (if government assistance or personal finances permitted). Serum levels of opn were assessed by enzyme-linked immunosorbent assay (elisa) before treatment was started. A group of 30 matched healthy women whose median serum opn level was 15 ng/dL were included, and that level was therefore defined as the cut-off value. In addition, opn gene mutation was determined by polymerase chain reaction (pcr). Correlations of pretreatment serum opn and opn gene mutation with various patient clinicopathologic variables, response to the treatment, progression-free survival (pfs), and overall survival (os) were assessed.

Results

Mean serum opn was highest in her2-amplified bca (64.4 ± 42.3 ng/dL), and then in triple-negative bca (55.9 ± 34.7 ng/dL), followed by the luminal B and A subtypes (38.4 ± 33.1 ng/dL and 36.3 ± 32.2 ng/dL respectively, p = 0.017). Testing by pcr revealed that opn gene mutation was highest in triple-negative bca (85% opn mutant vs. 15% non-mutant), and then in her2-overexpressed bca (80% opn mutant vs. 20% non-mutant), followed by luminal B bca (61.9% opn mutant vs. 38.1% non-mutant); the least expression was detected in luminal A bca (57.9% opn mutant vs. 42.1% non-mutant). Interestingly, patients with high serum opn and opn gene mutation experienced both poor pfs (median: 12 months vs. 14 months; p = 0.001) and poor os (median: 14 months vs. 18 months; p = 0.001). Moreover, participants with opn gene mutation experienced a poor response: of those with progressive disease, 74% had opn mutation and 26% had unmutated opn (p = 0.04). Additionally, high pretreatment serum opn was correlated with poor treatment response: 49.1 ± 33.8 ng/dL in patients with progressive disease and 35.5 ± 34.3 ng/dL in those who achieved a complete response, a partial response, or stable disease (p = 0.05). Strong concordance was found between high serum opn and opn gene mutation in 69 tumours (79.3%), and strong concordance was detected between normal or low serum opn and non-mutant opn in 28 tumours (60.8%).

Conclusions

The current prospective work helps to highlight opn as a valid prognostic biomarker for patients with metastatic bca and reveals that high pretreatment serum opn and opn gene mutation are both strongly linked with poor response and survival. Concordance between elisa and pcr results indicates that either method can be used for the evaluation of opn. Increased opn gene mutation in triple-negative bca could assist in tailoring the treatment response in this very aggressive tumour subtype and could be considered a targetable molecule in future studies.

Mesothelioma Biomarkers: Discovery in Search of Validation

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm that can only be treated successfully when correctly diagnosed and treated early. The asbestos-exposed population is a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. We review recent work with biomarker development in MPM and literature of the last 20 years on the most promising blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms are covered. SMRP is the only validated blood-based biomarker with diagnostic, monitoring and prognostic value. To strengthen development and testing of MPM biomarkers, cohorts for validation must be established by enlisting worldwide collaborations.

Mesothelioma Biomarkers: A Review Highlighting Contributions from the Early Detection Research Network

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm, which can be treated successfully only if correctly diagnosed and treated in early stages. The asbestos-exposed population serves as a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. This review details the recent work with biomarker development in MPM and the contributions of the NCI Early Detection Research Network Biomarker Developmental Laboratory of NYU Langone Medical Center. The literature of the last 20 years was reviewed to comment on the most promising of the blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms as well as novel studies such as "breath testing" are covered. Soluble mesothelin-related proteins (SMRP) have been characterized extensively and constitute an FDA-approved biomarker in plasma with diagnostic, monitoring, and prognostic value in MPM. Osteopontin is found to be a valuable prognostic biomarker for MPM, while its utility in diagnosis is slightly lower. Other biomarkers, such as calretinin, fibulin 3, and High-Mobility Group Box 1 (HMGB1), remain under study and need international validation trials with large cohorts of cases and controls to demonstrate any utility. The EDRN has played a key role in the development and testing of MPM biomarkers by enlisting collaborations all over the world. A comprehensive understanding of previously investigated biomarkers and their utility in screening and early diagnosis of MPM will provide guidance for further future research.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Mmu_circ_003795 regulates osteoblast differentiation and mineralization in MC3T3‑E1 and MDPC23 by targeting COL15A1

Circular RNAs (circRNAs) are a class of non-coding RNAs that exhibit important regulatory roles in various biological processes. However, the role of circRNAs and their potential role in osteoblast differentiation and mineralization is unclear. The aim of the present study was to investigate the expression of mmu_circ_003795 and its effect on collagen type XV α 1 chain (COL15A1). First, it was identified that the expression levels of mmu_circ_003795 and osteopontin (OPN) were upregulated in the induced cells. Silencing of mmu_circ_003795 reduced the gene and protein levels of COL15A1 and OPN, whereas the expression level of mmu-microRNA (miR)-1249-5p was upregulated. In addition, after 7 or 14 days of induction, alkaline phosphatase and Alizarin Red-S staining were decreased in the mmu_circRNA_003795 inhibitory group compared with the negative control group. In conclusion, mmu_circ_003795 may regulate osteoblast differentiation and mineralization in MC3T3-E1 and MDPC23 cells via mmu-miR-1249-5p by targeting COL15A1.

Osteopontin Mediates Cetuximab Resistance via the MAPK Pathway in NSCLC Cells

Background

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The high expression of osteopontin (OPN) is an important factor that aggravates drug resistance and causes a poor prognosis in this disease. Therefore, understanding the molecular mechanism of OPN is critical for the treatment and prognosis of NSCLC.

Methods

We used bioinformatics analysis to verify the expression of OPN in normal lung tissues and lung cancer tissues. Then we overexpressed and knocked down OPN in cell lines to detect cell proliferation, migration, invasion, and effects on signaling pathways. Finally, malignant progression and drug resistance induced by OPN were investigated by the wound healing assay, transwell assay, clone formation assay, and Western blot analysis.

Results

We verified that OPN was upregulated in NSCLC tissues, and its overexpression induced NSCLC cell proliferation, migration, and invasion via the mitogen-activated protein kinase (MAPK) pathway. Furthermore, overexpression of OPN reduced the sensitivity of NSCLC cells to cetuximab by upregulating MAPK pathway-related proteins. These results suggested that OPN promoted malignant progression and mediated drug resistance via the MAPK signaling pathway in NSCLC cells.

Conclusion

This study reveals the important role of OPN in NSCLC cells, making it a potential target for improving chemotherapy efficiency in patients with NSCLC.

Linking NRP2 With EMT and Chemoradioresistance in Bladder Cancer

Neuropilin-2 (NRP2) is a prognostic indicator for reduced survival in bladder cancer (BCa) patients. Together with its major ligand, vascular endothelial growth factor (VEGF)-C, NRP2 expression is a predictive factor for treatment outcome in response to radiochemotherapy in BCa patients who underwent transurethral resection. Therefore, we investigated the benefit of combining cisplatin-based chemotherapy with irradiation treatment in the BCa cell line RT112 exhibiting or lacking endogenous NRP2 expression in order to evaluate NRP2 as potential therapeutic target. We have identified a high correlation of NRP2 and the glioma-associated oncogene family zinc finger 2 (GLI2) transcripts in the cancer genome atlas (TCGA) cohort of BCa patients and a panel of 15 human BCa cell lines. Furthermore, we used in vitro BCa models to show the transforming growth factor-beta 1 (TGFβ1)-dependent regulation of NRP2 and GLI2 expression levels. Since NRP2 was shown to bind TGFβ1, associate with TGFβ receptors, and enhance TGFβ1 signaling, we evaluated downstream signaling pathways using an epithelial-to-mesenchymal transition (EMT)-assay in combination with a PCR profiling array containing 84 genes related to EMT. Subsequent target validation in NRP2 knockout and knockdown models revealed secreted phosphoprotein 1 (SPP1/OPN/Osteopontin) as a downstream target positively regulated by NRP2.

Downregulation of osteopontin inhibits browning of white adipose tissues through PI3K-AKT pathway in C57BL / 6 mice

Brown adipose tissue (BAT) plays important roles in regulating energy homeostasis and combating obesity. Accordingly, increasing the abundance and/or activating BAT would be effective and promising approaches to combat obesity and obesity-relative diseases. Our previous data in vitro have shown that osteopontin (OPN) induces the brown adipogenesis in 3T3-L1 cells via a phosphatidylinositol 3 kinase (PI3K)-AKT pathway. However, it is currently unknown whether OPN exerts such an effect on animals in vivo. Therefore, in the study we sought to investigate the pro-browning effects of OPN and to explore its underlying mechanisms by transfecting with Ad-GFP-aP2-OPN-shRNA to specifically down-regulate the OPN of white adipose tissue (WAT) in mice. Our present results show that downregulation of OPN in WAT exacerbates obesity and inhibits WAT-browning. Moreover, immunohistochemical results also exhibit that the downregulation of OPN significantly diminishes the expression and sub-cellular localization of UCP-1, PRDM16 and PGC-1α. Besides, the western blotting results reveal that the expression levels of PI3K, AKT-pS473 and PPARγ markedly reduce. Consequently, we conclude that the downregulation of OPN inhibits the browning of WAT through inhibiting the expression of PPARγ mediated by the PI3K-AKT pathway. The findings suggest that OPN is involved in regulation of WAT-browning and regulating its expression would become a potential strategy to combat obesity and obesity-relative metabolic diseases.

Liquid Biopsy in Malignant Pleural Mesothelioma: State of the Art, Pitfalls, and Perspectives

Malignant pleural mesothelioma (MPM) is an aggressive tumor linked to asbestos exposure. Although the risk factors for MPM are well-known, the majority of MPM patients are diagnosed at an advanced stage and have a very poor prognosis. Circulating biomarkers for early diagnosis remain to be identified, and the current standard for MPM diagnosis relies on pleural biopsies. Robust non-invasive tests for the screening of asbestos-exposed subjects are therefore an important unmet clinical need. This review provides a critical summary of recent liquid biopsy-based studies aimed at discovering novel blood-based circulating biomarkers for the early diagnosis and prognostic stratification of MPM patients.

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.

New Insights in Bladder Cancer Diagnosis: Urinary miRNAs and Proteins

Bladder cancer is the 10th-most common cancer worldwide. The diagnosis and follow-up of patients require costly invasive methods and due to these expenses, bladder cancer continues to be one of the expensive malignancies. Early diagnosis is crucial in bladder cancer as it is in other cancers; therefore, non-invasive biomarkers for early diagnosis are very important. In this review, we aimed to focus on the most recent investigations on potential urinary micro RNA (miRNA) and protein biomarkers for bladder cancer diagnosis and their associated pathways. Studies performed by different groups were compiled and the biomarker properties of various proteins and miRNAs in the urine of bladder cancer patients were evaluated. Key studies were obtained by searching keywords “bladder cancer, urinary miRNA, urinary protein, urinary biomarker”. Targets and the pathways of the miRNAs and proteins were analyzed according to mirBase Catalogue and Panther Database. The major pathways that are targeted by aberrantly expressed miRNAs are Cholecystokinin receptor (CCKR), p53, Wnt signaling pathway, and feedback loops. We hereby conclude that urinary micro RNAs and proteins are promising candidates for bladder cancer diagnosis. It should be noted that urine collection, storage conditions, choice of fraction, and normalization strategies should be standardized.

An osteopontin/CD44 immune checkpoint controls CD8+ T cell activation and tumor immune evasion

Despite breakthroughs in immune checkpoint inhibitor (ICI) immunotherapy, not all human cancers respond to ICI immunotherapy and a large fraction of patients with the responsive types of cancers do not respond to current ICI immunotherapy. This clinical conundrum suggests that additional immune checkpoints exist. We report here that interferon regulatory factor 8 (IRF8) deficiency led to impairment of cytotoxic T lymphocyte (CTL) activation and allograft tumor tolerance. However, analysis of chimera mice with competitive reconstitution of WT and IRF8-KO bone marrow cells as well as mice with IRF8 deficiency only in T cells indicated that IRF8 plays no intrinsic role in CTL activation. Instead, IRF8 functioned as a repressor of osteopontin (OPN), the physiological ligand for CD44 on T cells, in CD11b+Ly6CloLy6G+ myeloid cells and OPN acted as a potent T cell suppressor. IRF8 bound to the Spp1 promoter to repress OPN expression in colon epithelial cells, and colon carcinoma exhibited decreased IRF8 and increased OPN expression. The elevated expression of OPN in human colon carcinoma was correlated with decreased patient survival. Our data indicate that myeloid and tumor cell-expressed OPN acts as an immune checkpoint to suppress T cell activation and confer host tumor immune tolerance.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Osteopontin-targeted probe detects orthotopic breast cancers using optoacoustic imaging

Improved detection of breast cancer using highly sensitive, tumor-specific imaging would facilitate diagnosis, surveillance and assessment of response to treatment. We conjugated osteopontin peptide to an infrared fluorescent dye to serve as a contrast agent for detection of breast cancer by multispectral optoacoustic tomography (MSOT). Selective binding of the osteopontin-based probe was identified using flow cytometry and near infrared fluorescent imaging in triple negative and HER2 positive breast cancer cell lines in vitro. Osteopontin-750 accumulation was evaluated in vivo using MSOT with secondary confirmation of signal accumulation using near infrared fluorescent imaging. The osteopontin-based probe demonstrated binding to breast cancer cells in vitro. Similarly, after intravenous administration of the osteopontin-750 probe, it accumulated preferentially in the subcutaneous breast tumor in nude mice (557 MSOT a.u. compared to untargeted organs such as kidney (53.7 MSOT a.u.) and liver (32.1 MSOT a.u.). At 2.5 h post-injection, signal intensity within the tumor was 9.7 and 17 times greater in the tumor bed than in the kidney or liver, respectively. Fluorescence imaging ex vivo comparing tumor signal to that of nontarget organs confirmed the results in vivo. MSOT imaging demonstrated selective accumulation of the fluorescent osteopontin targeting probe to tumor sites both in vitro and in vivo, and provided high-resolution images. Further development of this tool is promising for advanced diagnostic imaging, disease surveillance and therapeutic models that limit nontarget toxicity.

Osteopontin promotes cancer cell drug resistance, invasion, and lactate production and is associated with poor outcome of patients with advanced non-small-cell lung cancer

Background

Osteopontin (OPN), a member of the small integrin binding ligand N-linked glycoprotein family, has been analyzed in numerous types of human malignancy.

Purpose

The present study detected the expression levels of OPN and evaluated its role in tumor progression in patients with non-small cell lung cancer (NSCLC).

Patients and methods

OPN expression levels were detected using immunohistochemistry in 101 NSCLC tumors. The mRNA and protein levels have significant difference between advanced NSCLC and stage I/II NSCLC. The drug resistance, invasive ability and lactate production of NSCLC cancer cell lines (A549 and SK-MES-1) were detected in cancer cells with the disturbance of OPN.

Results

Immunostaining indicated that OPN was primarily expressed in the cytoplasm of NSCLC cells. Moreover, OPN correlates with NSCLC clinical traits. The results demonstrated that OPN expression levels significantly correlated with cancer differentiation, distant metastasis and the efficacy of platinum-based treatment. Notably, the results identified OPN expression levels as a potential factor for predicting the response of cells to first-line platinum-based chemotherapy using multivariate analysis, as well as predicting cancer differentiation and distant metastasis. Additionally, the abrogation of OPN levels reduced lactate production in NSCLC cells and occurred along side with the downregulation of lactate dehydrogenase A (LDHA).

Conclusion

The results of the current study suggest that OPN may be able to predict poor prognosis and cisplatin resistance in patients.

The multiple functions and mechanisms of osteopontin

Osteopontin (OPN) is a highly phosphorylated glycophosphoprotein having acidic characteristics and rich in aspartic acid. OPN, a multifunctional protein, has important functions on cardiovascular diseases, cancer, diabetes and kidney stone diseases and in the process of inflammation, biomineralization, cell viability and wound healing. Osteopontin acts on organisms by playing a key role in secretion levels of interleukin-10 (IL-10), interleukin-12 (IL-12), interleukin-3 (IL-3), interferon-γ (IFN-γ), integrin αvB3, nuclear factor kappa B (NF-kB), macrophage and T cells, regulating the osteoclast function and affecting CD44 receptors. The aim of the present review is to address majority of different functions of OPN protein which are known, suspected or suggested through the data obtained about this protein yet.

CNS Langerhans cell histiocytosis: Common hematopoietic origin for LCH-associated neurodegeneration and mass lesions

BACKGROUND

Central nervous system Langerhans cell histiocytosis (CNS-LCH) brain involvement may include mass lesions and/or a neurodegenerative disease (LCH-ND) of unknown etiology. The goal of this study was to define the mechanisms of pathogenesis that drive CNS-LCH.

METHODS

Cerebrospinal fluid (CSF) biomarkers including CSF proteins and extracellular BRAFV600E DNA were analyzed in CSF from patients with CNS-LCH lesions compared with patients with brain tumors and other neurodegenerative conditions. Additionally, the presence of BRAFV600E was tested in peripheral mononuclear blood cells (PBMCs) as well as brain biopsies from LCH-ND patients, and the response to BRAF-V600E inhibitor was evaluated in 4 patients with progressive disease.

RESULTS

Osteopontin was the only consistently elevated CSF protein in patients with CNS-LCH compared with patients with other brain pathologies. BRAFV600E DNA was detected in CSF of only 2/20 (10%) cases, both with LCH-ND and active lesions outside the CNS. However, BRAFV600E+ PBMCs were detected with significantly higher frequency at all stages of therapy in LCH patients who developed LCH-ND. Brain biopsies of patients with LCH-ND demonstrated diffuse perivascular infiltration by BRAFV600E+ cells with monocyte phenotype (CD14+ CD33+ CD163+ P2RY12- ) and associated osteopontin expression. Three of 4 patients with LCH-ND treated with BRAF-V600E inhibitor experienced significant clinical and radiologic improvement.

CONCLUSION

In LCH-ND patients, BRAFV600E+ cells in PBMCs and infiltrating myeloid/monocytic cells in the brain is consistent with LCH-ND as an active demyelinating process arising from a mutated hematopoietic precursor from which LCH lesion CD207+ cells are also derived. Therapy directed against myeloid precursors with activated MAPK signaling may be effective for LCH-ND. Cancer 2018;124:2607-20. © 2018 American Cancer Society.

TRIM66 expression in non-small cell lung cancer: A new predictor of prognosis

OBJECTIVE

The tripartite motif-containing protein (TRIM) family is involved in important biological processes such as the cell cycle, cell apoptosis, and innate immunity of virus. This study aimed to investigate TRIM66 expression and its predictive role in non-small cell lung cancer (NSCLC) patients.

METHODS

We detected the expression levels of TRIM66 protein and TRIM66 mRNA in NSCLC tissues, and evaluated the prognostic role of TRIM66 in NSCLC.

RESULTS

TRIMM66 was highly expressed in NSCLC tissues compared with normal paracancerous tissues (P= 0.001). The high TRIM66 expression closely associated with lymph node metastasis and TNM stage in NSCLC patients (P< 0.05). Kaplan-Meier survival model indicated that survival time of NSCLC patients in the high TRIM66 expression group were markedly lower than those in the low expression group (P< 0.05). Cox regression analysis showed that high expression of TRIM66 is associated with poor prognosis in NSCLC patients.

CONCLUSION

TRIM66 can be serve as an important molecular marker for predicting the prognosis in NSCLC patients.

Biological role of site-specific O-glycosylation in cell adhesion activity and phosphorylation of osteopontin

Osteopontin (OPN) is an extracellular glycosylated phosphoprotein that promotes cell adhesion by interacting with several integrin receptors. We previously reported that an OPN mutant lacking five O-glycosylation sites (Thr¹³⁴/Thr¹³⁸/Thr¹⁴³/Thr¹⁴⁷/Thr¹⁵²) in the threonine/proline-rich region increased cell adhesion activity and phosphorylation compared with the wild type. However, the role of O-glycosylation in cell adhesion activity and phosphorylation of OPN remains to be clarified. Here, we show that site-specific O-glycosylation in the threonine/proline-rich region of OPN affects its cell adhesion activity and phosphorylation independently and/or synergistically. Using site-directed mutagenesis, we found that OPN mutants with substitution sets of Thr¹³⁴/Thr¹³⁸ or Thr¹⁴³/Thr¹⁴⁷/Thr¹⁵² had decreased and increased cell adhesion activity, respectively. In contrast, the introduction of a single mutation into the O-glycosylation sites had no effect on OPN cell adhesion activity. An adhesion assay using function-blocking antibodies against αvβ3 and β1 integrins, as well as αvβ3 integrin-overexpressing A549 cells, revealed that site-specific O-glycosylation affected the association of OPN with the two integrins. Phosphorylation analyses using phos-tag and LC-MS/MS indicated that phosphorylation levels and sites were influenced by the O-glycosylation status, although the number of O-glycosylation sites was not correlated with the phosphorylation level in OPN. Furthermore, a correlation analysis between phosphorylation level and cell adhesion activity in OPN mutants with the site-specific O-glycosylation showed that they were not always correlated. These results provide conclusive evidence of a novel regulatory mechanism of cell adhesion activity and phosphorylation of OPN by site-specific O-glycosylation.

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.

Comparison between Plasma and Serum Osteopontin Levels: Usefulness in Diagnosis of Epithelial Malignant Pleural Mesothelioma

Background

A potential role of serum osteopontin (OPN) and serum mesothelin-related peptide (SMRP) in the diagnosis of malignant pleural mesothelioma (MPM) has been recently reported. Although the most important data regarding the role of OPN in MPMs derive from the marker's measurement in serum samples, most commercial laboratory kits for OPN assay are suitable only for measuring plasma levels, as indicated by the manufacturers. Our study aimed to evaluate the influence of preanalytic variables on serum and plasma OPN, to compare serum and plasma OPN in the same population, and to assess whether OPN levels can aid in the diagnostic distinction of patients with MPM versus benign respiratory disease (BRD) and healthy subjects exposed to asbestos.

Methods

The influence of preanalytic variables such as the length of storage at different temperatures and the number of thawings of samples on serum and plasma OPN measurements were evaluated. We measured OPN in 239 plasma samples from 207 asbestos-exposed subjects including 94 healthy controls and 113 subjects with BRD, and 32 patients with epithelial MPM, employing a commercially available ELISA. Serum OPN was measured in 196 of the same 239 samples from 80 healthy subjects, 92 BRD patients and 24 MPM patients.

Results

We found that both serum and plasma OPN levels were influenced by storage at –80°C and by the number of thawings, while serum OPN was influenced also by storage at room temperature. Plasma and serum OPN levels were significantly higher (p<0.0001) in patients with epithelial MPM than in the healthy control group and the BRD group. The application of a ROC curve for plasma OPN resulted in an AUC value of 0.780 with a best cutoff of 878.65 ng/mL, with a sensitivity of 68.8% and a specificity of 84.5%. The AUC for sOPN was 0.725 with a best cutoff of 16.06 ng/mL, with a sensitivity of 62.5% and a specificity of 87.3%. Within the control group no significant correlation was observed between age, duration of asbestos exposure, pack-years in current smokers, lung function or imaging parameters and plasma or serum OPN.

Conclusions

These data suggest that plasm OPN and serum OPN are not influenced by confounding factors such as age, smoking habits and asbestos exposure. Plasma and serum OPN may be useful markers in the diagnosis of epithelial MPM in addition to traditional radiological exams. However, in our opinion plasma OPN is preferable to serum OPN because it is more stable and measurements of OPN in serum are less reliable.

BCSC-1 suppresses human breast cancer metastasis by inhibiting NF-κB signaling

Breast cancer suppressor candidate-1 (BCSC-1; also termed von Willebrand factor A domain containing 5A and LOH11CR2A) is a newly identified candidate tumor suppressor gene that has been implicated in several types of cancer in previous studies. However, there have been few reports about the association between BCSC-1 and human breast cancer in recent years. In the present study, the expression of BCSC-1 in breast cancer was determined by immunohistochemistry (IHC) staining of tissue microarrays and clinical tissue specimens. Subsequently, BCSC-1 gene expression was evaluated in different breast cancer cell lines by quantitative polymerase chain reaction and the MDA-MB-231 cell line was selected for further use in subsequent experiments, due to its low BCSC-1 expression. An MDA-MB-231 cell line with stable overexpression of BCSC-1 was established through transfection with plasmid containing the BCSC-1 gene, and then screening for G418 resistance. Wound-healing, migration and invasion assays were conducted to detect the effect of BCSC-1 on MDA-MB-231 cells. Furthermore, changes in matrix metalloproteinases (MMPs), osteopontin (OPN) and the nuclear factor-κB (NF-κB) pathway were detected in the current study. Additionally, stable silencing of BCSC-1 expression in MCF-7 cells was performed using a lentivirus. The results of IHC indicated that BCSC-1 is expressed at low levels in breast cancer tissues compared with in normal breast tissue. Results of the wound healing, migration and invasion assays demonstrated that BCSC-1 overexpression reduced the metastasis ability of MDA-MB-231 cells in vitro. Further research confirmed that the BCSC-1 overexpression reduced the expression levels of MMP7, MMP9 and OPN, and the phosphorylation of NF-κB p65. Furthermore, inhibition of BCSC-1 via lentivirus-mediated RNA interference revealed that the downregulation of BCSC-1 increased the invasive ability of MCF-7 cells. In summary, the results demonstrated that BCSC-1 is expressed at low levels in breast cancer tissues, and that it can suppress human breast cancer cell migration and invasion, potentially altering the expression of MMP7, MMP9, OPN, and the activity of the NF-κB pathway. Therefore, BCSC-1 may be useful as a biomarker for the treatment of breast cancer in the future.

The role of osteopontin in the progression of solid organ tumour

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

Osteopontin Expression According to Molecular Profile of Invasive Breast Cancer: A Clinicopathological and Immunohistochemical Study

Osteopontin (OPN) is a secreted, calcium-binding phosphorylated glycoprotein involved in several physiological and pathological events such as angiogenesis, apoptosis, inflammation, wound healing, vascular remodeling, calcification of mineralized tissues, and induction of cell proteases. There is growing interest in the role of OPN in breast cancer. In an attempt to obtain new insight into the pathogenesis of OPN-associated breast carcinomas, an immunohistochemical panel with 17 primary antibodies including cytokeratins and key regulators of the cell cycle was performed in 100 formalin-fixed paraffin-embedded samples of invasive breast carcinomas. OPN was expressed in 65% of tumors and was negatively correlated with estrogen (p=0.0350) and progesterone (p=0.0069) receptors, but not with the other markers and clinicopathological features evaluated including age, menstrual status, pathological grading, tumor size, and metastasis. There was no correlation between OPN expression and carcinomas of the basal-like phenotype (p=0.1615); however, OPN correlated positively with c-erbB-2 status (p=0.0286) and negatively with carcinomas of the luminal subtype (p=0.0353). It is well known that carcinomas overexpressing c-erbB-2 protein have a worse prognosis than luminal tumors. Here, we hypothesize that the differential expression of OPN in the first subtype of carcinomas may contribute to their more aggressive behavior.

Inducible T-cell co-stimulators regulate the proliferation and invasion of human hepatocellular carcinoma HepG2 cells

Background

This study determined the regulatory effects of inducible T-cell co-stimulators (ICOS) in human hepatocellular carcinoma HepG2 cells using a RNA interference (RNAi) technique.

Methods

A RNAi technique was used to knockdown the expression of ICOS. ICOS expression after knockdown was detected as mRNA and protein levels by RT-PCR and Western blot, respectively. A MTT colorimetric assay was used to detect cell proliferation, and the Transwell assay was used to detect cell invasion. Western blot was carried out to detect the level of Bcl-2, AKT, and PI3K protein expression in different groups.

Results

The proliferation of HepG2 cells were significantly decreased after ICOS siRNA transfection (EG group). Similarly, the results of the Transwell experiment showed that invasion of HepG2 cells in the EG group was clearly reduced compared to the negative control (NC) and blank control groups (CON). Western blot analysis showed that knockdown of ICOS expression reduced the levels of Bcl-2 and AKT, and also significantly up-regulated the level of PI3K phosphorylation (P < 0.01).

Conclusion

Down-regulating ICOS expression in HepG2 cells suppressed cell proliferation and invasion. The underlying mechanism may be related to the expression of the downstream factor, PI3K/AKT.

Serum mesothelin and other biomarkers: what have we learned in the last decade?

In the last decade there is been much interest in noninvasive, economic and well-accepted diagnostic tests for screening of subjects exposed to asbestos, and in patients with malignant pleuric mesothelioma (MPM) for diagnosis or monitoring response to treatment. Several biomarkers have been suggested as tools for screening and early diagnosis of MPM. Currently, in patients with MPM, have been reported high levels of soluble mesothelin-related peptides (SMRP), plasmatic osteopontin (pOPN), vimentin, fibulin-3 and many others as promising marker for diagnosis, even their use in prevention monitoring is still discussed. In this type of disease, a key role could be played by miRNAs, which expression has been investigated in a large series of MPM to examine new pathways useful in diagnosis, prognosis and therapy. An altered expression of some proteins has been reported, useful as biomarkers, in comparative proteomic analysis of malignant pleural mesothelioma. New promising markers are nowadays under study and alone or better in combination, they'll be very helpful in diagnosing, monitoring mesothelioma patients or for screening of risk groups.

Biomarkers in the prevention and follow-up of workers exposed to asbestos

Although in most developed countries the use of asbestos is banned, there is still a consistent portion of the world where asbestos extraction, trading and manufacturing of asbestos-made products is largely diffuse. Worldwide, hundreds of millions of people are at risk of developing an asbestos caused disease because of occupational, environmental or domestic exposure. The WHO estimates that asbestos is responsible for more than 100,000 deaths yearly. This scenario has prompted the research on biomarkers potentially useful for early diagnosis, prognosis and preventive programs on exposed population as well. Here we reviewed the up-to-date literature on this field of research highlighting that along with mesothelin and osteopontin (OPN), some more recently investigated molecules, such as high mobility group box 1 (HMGB1) protein, fibulin-3 and some miRNAs showed very promising. Most of the carried-out studies showed an interesting diagnostic and prognostic performance of some biomarkers, but since they usually lack adequate either specificity or sensitivity, their use in screening or in preventive programs is still not recommended on a routine basis. However, this review suggests the need for more reliable experimental design involving larger population and preferring longitudinal screening of asbestos exposed individuals rather than a single baseline assessment investigation. In addition, given their better diagnostic accuracy, the use of panels including several biomarkers is highly recommended.