Clinical Significance of Circulating Osteopontin Levels in Patients With Lung Cancer and Correlation With VEGF and MMP-9

Thrombin Cleavage of Osteopontin and the Host Anti-Tumor Immune Response

Osteopontin (OPN) is a multi-functional protein that is involved in various cellular processes such as cell adhesion, migration, and signaling. There is a single conserved thrombin cleavage site in OPN that, when cleaved, yields two fragments with different properties from full-length OPN. In cancer, OPN has tumor-promoting activity and plays a role in tumor growth and metastasis. High levels of OPN expression in cancer cells and tumor tissue are found in various types of cancer, including breast, lung, prostate, ovarian, colorectal, and pancreatic cancer, and are associated with poor prognosis and decreased survival rates. OPN promotes tumor progression and invasion by stimulating cell proliferation and angiogenesis and also facilitates the metastasis of cancer cells to other parts of the body by promoting cell adhesion and migration. Furthermore, OPN contributes to immune evasion by inhibiting the activity of immune cells. Thrombin cleavage of OPN initiates OPN's tumor-promoting activity, and thrombin cleavage fragments of OPN down-regulate the host immune anti-tumor response.

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.

Osteopontin Signaling in Shaping Tumor Microenvironment Conducive to Malignant Progression

Context-dependent reciprocal crosstalk between cancer and surrounding stromal cells in the tumor microenvironment is imperative for the regulation of various hallmarks of cancer. A myriad of growth factors, chemokines, and their receptors aids in the interaction between cancer cells and tumor microenvironmental components. Osteopontin is a chemokine-like protein, overexpressed in different types of cancers. Osteopontin plays a crucial role in orchestrating dialogue between cancer and stromal cells. Osteopontin, in tumor microenvironment, is produced in tumor as well as stromal cells. Tumor-derived osteopontin regulates proliferation, migration, activation, and differentiation of different types of stromal cells. Osteopontin secreted from tumor cells regulates the generation of cancer-associated fibroblasts from resident fibroblasts and mesenchymal stem cells. Osteopontin also shapes immunosuppressive tumor microenvironment by controlling regulatory T cells and tumor-associated macrophages. Moreover, secretion of osteopontin from tumor stroma has been highly documented. Stromal cell-derived osteopontin induces epithelial-to-mesenchymal transition, angiogenesis, metastasis, and cancer stem cell enrichment. Tumor- or stroma-derived osteopontin mainly functions through binding with cell surface receptors, integrins and CD44, and activates downstream signaling events like PI-3 kinase/Akt and MAPK pathways. Presumably, disrupting the communication between the tumor cells and surrounding microenvironment by targeting osteopontin-regulated signaling using specific antibodies, small-molecule inhibitors, and chemotherapeutic agents is a novel therapeutic strategy for clinical management of cancer.

MiR-181a Promotes Apoptosis and Reduces Cisplatin Resistance by Inhibiting Osteopontin in Cervical Cancer Cells

Objective: In this study, the authors established a cervical cancer cisplatin (DDP) drug-resistant cell line to explore the role of miR-181a in the regulation of osteopontin (OPN) expression and the proliferation, apoptosis, as well as DDP resistance of cervical cancer cells. Materials and Methods: Dual luciferase reporter gene assay was performed to validate the targeted relationship between miR-181a and OPN. The DDP-resistant cell line CaSki/DDP was established to compare the expressions of miR-181a and OPN. The cell proliferation activity was detected by CCK-8 assay. CaSki/DDP cells were divided into miR-NC group and miR-181a mimic group followed by analysis of cell apoptosis by flow cytometry, and the cell proliferation by EdU staining. Results: There was a targeted relationship between miR-181a and OPN mRNA. MiR-181a expression was significantly lower, while OPN mRNA and protein levels were significantly higher in CaSki/DDP cells than that in CaSki cells. Compared with the miR-NC group, OPN mRNA and protein were significantly decreased, cell apoptosis was significantly increased, and cell proliferation ability was significantly attenuated in miR-181a mimic transfection group. Conclusions: The decrease of miR-181a expression and the upregulation of OPN expression are related to the DDP resistance of cervical cancer cells. Overexpression of miR-181a can inhibit the expression of OPN, induce cell apoptosis cells, restrain cell proliferation, and reduce DDP resistance in cervical cancer cells.

Serous IFNA3 predicts unfavorable prognosis in lung cancer via abnormal activation of AKT signaling

This study addresses the demand through datamining The Cancer Genome Atlas (TCGA) database and elucidates mechanistic involvements of interferon alpha 8 (IFNA8) in lung cancer. The overall survival and disease-free survival of lung cancer patients in respect to IFNA8 expression level were analyzed. IFNA8 expression levels in both serum and tumor tissue were determined by real-time polymerase chain reaction. The diagnostic value of serous IFNA8 in lung cancer was assessed by receiver operating characteristic (ROC) curve analysis. Cell viability and proliferation were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Cell Counting Kit-8 assays. in vivo pro-tumor effect of IFNA8 was evaluated using xenograft tumor model. The metastasis-prone behaviors were determined by Transwell chamber assay and tail vein-injection in mice. Protein levels of p-AKT, total AKT, and endogenous reference actin were analyzed by western blot. We uncovered high IFNA8 associated with unfavorable overall survival and disease-free survival in lung cancer patients from TCGA. We further characterized the aberrant over-expression of IFNA8 in both peripheral blood and solid tumor from our clinical patient panel, and ROC analysis suggested its potential diagnostic value. Ectopic over-expression of IFNA8 promoted viability and proliferation in both A549 and H1299 cells in vitro and accelerated xenograft tumor growth in vivo. Furthermore, IFNA8 facilitated migration, invasion, and metastasis of A549 cells in vivo. Mechanistically, we disclosed the over-activation of AKT signaling in IFNA8-proficient A549 cells, inhibition of which completely abolished the pro-tumor effects of IFNA8. We have identified IFNA8 as a novel biomarker for either diagnostic or prognostic purpose in lung cancer, which is mechanistically associated with abnormal activation of AKT signaling.

Tumor Extracellular Matrix Remodeling: New Perspectives as a Circulating Tool in the Diagnosis and Prognosis of Solid Tumors

In recent years, it has become increasingly evident that cancer cells and the local microenvironment are crucial in the development and progression of tumors. One of the major components of the tumor microenvironment is the extracellular matrix (ECM), which comprises a complex mixture of components, including proteins, glycoproteins, proteoglycans, and polysaccharides. In addition to providing structural and biochemical support to tumor tissue, the ECM undergoes remodeling that alters the biochemical and mechanical properties of the tumor microenvironment and contributes to tumor progression and resistance to therapy. A novel concept has emerged, in which tumor-driven ECM remodeling affects the release of ECM components into peripheral blood, the levels of which are potential diagnostic or prognostic markers for tumors. This review discusses the most recent evidence on ECM remodeling-derived signals that are detectable in the bloodstream, as new early diagnostic and risk prediction tools for the most frequent solid cancers.

Therapeutic effect of combined hyperbaric oxygen and radiation therapy for single brain metastasis and its influence on osteopontin and MMP-9

The present study aimed to investigate the therapeutic effect of combined hyperbaric oxygen and radiation therapy for the treatment of single brain metastasis (SBM), as well as its influence on osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9). A total of 86 patients with SBM were admitted to Hongqi Hospital from January 2013 to January 2016 and those included within the study were randomly divided into two groups. The control group was only treated with whole brain radiotherapy, while the observation group was treated with hyperbaric oxygenation combined with whole brain radiotherapy. OPN and MMP-9 expression was measured in each group by ELISA and the results prior to and following treatment were compared. The total effective rate (patients with complete remission, partial remission or stabilized lesions) in the observation group (95.3%) was significantly increased compared with the control group (67.4%). However, the OPN and MMP-9 protein levels observed in the observation group were significantly reduced compared with the control group (P<0.05). In addition, the quality of life and the incidence of adverse reactions in the observation group were significantly improved compared with the control group (P<0.05). For patients with SBM, hyperbaric oxygenation combined with radiotherapy may improve the efficiency of treatment and should be considered for further investigation and use within a clinical setting.

Efficacy of radiotherapy on intermediate and advanced lung cancer and its effect on dynamic changes of serum vascular endothelial growth factor and matrix metalloproteinase-9

The present study intended to investigate efficacy of radiotherapy in the treatment of intermediate and advanced stage lung cancer and the effects on serum vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9). Serum levels of VEGF and MMP-9 of 77 patients with intermediate or advanced lung cancer were detected before and after the treatment. At the same time, 19 healthy people were selected as the control group. Gelatin zymography was applied to measure the activity of serum MMP-9, ELISA was performed to detect the VEGF and MMP-9 levels in the peripheral blood and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the messenger RNA (mRNA) levels of VEGF and MMP-9 in serum. Results indicated that the overall response rate of radiotherapy on intermediate and advanced lung cancer reached 70.1%. Levels of serum VEGF and MMP-9 in the effective treatment group were significantly lower than those before the treatment (P<0.05). Furthermore, expression levels of VEGF and MMP-9 in the effective radiotherapy group were significantly lower than those in ineffective group (P<0.05), MMP-9 activity before treatment was significantly higher than that after treatment (P<0.05) and expression levels of VEGF and MMP-9 mRNA before treatment were significantly elevated compared with those after treatment (P<0.05). The results suggested that the expression levels of serum VEGF and MMP-9 may be useful indicators for the evaluation of the efficacy of radiotherapy in the treatment of intermediate and advanced lung cancer.

Clinical validation of a blood-based classifier for diagnostic evaluation of asymptomatic individuals with pulmonary nodules

BACKGROUND

The number of pulmonary nodules detected in the US is expected to increase substantially following recent recommendations for nationwide CT-based lung cancer screening. Given the low specificity of CT screening, non-invasive adjuvant methods are needed to differentiate cancerous lesions from benign nodules to help avoid unnecessary invasive procedures in the asymptomatic population. We have constructed a serum-based multi-biomarker panel and assessed its clinical accuracy in a retrospective analysis of samples collected from participants with suspicious radiographic findings in the Prostate, Lung, Chest and Ovarian (PLCO) cancer screening trial.

METHODS

Starting with a set of 9 candidate biomarkers, we identified 8 that exhibited limited pre-analytical variability with increasing clotting time, a key pre-analytical variable associated with the collection of serum. These 8 biomarkers were evaluated in a training study consisting of 95 stage I NSCLC patients and 186 smoker controls where a 5-biomarker pulmonary nodule classifier (PNC) was selected. The clinical accuracy of the PNC was determined in a blinded study of asymptomatic individuals comprising 119 confirmed malignant nodule cases and 119 benign nodule controls selected from the PLCO screening trial.

RESULTS

A PNC comprising 5 biomarkers: CEA, CYFRA 21-1, OPN, SCC, and TFPI, was selected in the training study. In an independent validation study, the PNC resolved lung cancer cases from benign nodule controls with an AUC of 0.653 (p < 0.0001). CEA and CYFRA 21-1, two of the markers included in the PNC, also accurately distinguished malignant lesions from benign controls.

CONCLUSIONS

A 5-biomarker blood test has been developed for the diagnostic evaluation of asymptomatic individuals with solitary pulmonary nodules.

Osteopontin induced vascular endothelial growth factor production in dispersed nasal polyp cells through the phosphatidylinositol 3-kinase-protein kinase B and the extracellular signal-regulated kinase 1/2 pathways

BACKGROUND

Osteopontin (OPN) is involved in cell survival, migration, and angiogenesis. The role of OPN in inducing angiogenesis in tumor has been confirmed. In this study, we investigated the expression of OPN in patients with chronic rhinosinusitis (CRS) with nasal polyp (NP) and the relationship of OPN with vascular endothelial growth factor (VEGF) production.

METHODS

We enrolled 45 subjects with CRS (25 with CRS with NPs [CRSwNP] and 20 subjects with CRS without NPs [CRSsNP]), and with 14 normal controls to determine the expression of OPN and VEGF. The distribution, messenger RNA (mRNA), and protein levels of OPN and VEGF were examined by immunohistochemistry, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively. The effect of OPN on the VEGF production was tested in dispersed NP cells (DNPC) and the involved signaling pathways were examined by Western blot.

RESULTS

In NP tissue of the subjects with CRSwNP, the epithelial cells, interstitial cells, glandular cells, and endothelial cells were positive for OPN and VEGF staining, whereas OPN and VEGF immunoactivity in specimens of subjects with CRSsNP and in normal controls was significantly reduced. We found that the immunostainings, the mRNA expression, and the protein levels of OPN and VEGF were significantly increased in NPs compared with normal controls. OPN induced VEGF production by DNPCs in a time- and dose-dependent manner through phosphatidylinositol 3-kinase- protein kinase B and the extracellular signal-regulated kinase 1/2 pathway. Moreover, VEGF also induced OPN production, which formed a positive feedback between OPN and VEGF.

CONCLUSION

Our findings demonstrated that OPN and VEGF were overproduced in NPs and that OPN induced VEGF production, which indicated that OPN-VEGF axis might contribute to angiogenesis in NPs.

Human osteopontin: Potential clinical applications in cancer (Review)

Human osteopontin (OPN) is a glycosylated phosphoprotein which is expressed in a variety of tissues in the body. In recent years, accumulating evidence has indicated that the aberrant expression of OPN is closely associated with tumourigensis, progression and most prominently with metastasis in several tumour types. In this review, we present the current knowledge on the expression profiles of OPN and its main splice variants in human cancers, as well as the potential implications in patient outcome. We also discuss its putative clinical application as a cancer biomarker and as a therapeutic target.