Involvement of osteopontin and its signaling molecule CD44 in clinicopathological features of adult T cell leukemia

Umbelliprenin improved anti-proliferative effects of ionizing radiation on adult T-cell leukemia/lymphoma cells via interaction with CDK6; an in vitro and in silico study

Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy with poor survival rates. The efficacy of radiotherapy in ATL needs enhancement with radiosensitizing agents. This study investigated whether umbelliprenin (UMB) could improve the therapeutic effects of ionizing radiation (IR) in ATL cells. UMB, a naturally occurring prenylated coumarin, exhibits anticancer properties and has shown synergistic effects when combined with chemotherapeutic drugs. Despite this promising profile, there is a notable lack of research on its potential combinatorial effects with IR, particularly for ATL treatment. UMB was extracted from Ferula persica using thin layer chromatography. MT-2 cells were treated with UMB alone and in combination with various doses of IR, and cell proliferation was assessed via alamarBlue assay. Flow cytometry with annexin V and PI staining was conducted, and candidate gene expression was analyzed by qPCR. In silico analysis involved identifying pathogenic targets of ATL, constructing protein-protein interaction (PPI) networks, and evaluating CDK6 expression in MT-2 cells. Molecular docking was used to determine the interaction between UMB and CDK6. The alamarBlue assay and flow cytometry showed that pretreating ATL cells with UMB significantly (p < .0001) enhanced anti-proliferative effects of IR. The combination index indicated a synergistic effect between UMB and IR. qPCR revealed significant (p < .0001) downregulation of CD44, CDK6, c-MYC, and cFLIPL, and overexpression of cFLIPS. Computational analysis identified CDK6 as a hub gene in the PPI network, and CDK6 overexpression was confirmed in MT-2 cells. Molecular docking revealed a favorable binding interaction between UMB and the ATP-binding site of CDK6, with a JAMDA score of -2.131, surpassing the control selonsertib. The current study provides evidence that UMB enhances the anti-proliferative effects of IR on ATL cells, and highlights the significance of targeting CDK6 in combinatorial approaches.

THP-1 cell line model for tuberculosis: A platform for in vitro macrophage manipulation

Macrophages are large mononuclear phagocytic cells that play a vital role in the immune response. They are present in all body tissues with extremely heterogeneous and plastic phenotypes that adapt to the organs and tissues in which they live and respond in the first-line against invading microorganisms. Tuberculosis (TB) is caused by the pathogenic bacteria Mycobacterium tuberculosis (Mtb), which is among the top 10 global infectious agents and the leading cause of mortality, ranking above human immunodeficiency virus (HIV), as a single infectious agent. Macrophages, upon Mtb infection, not only phagocytose the bacteria and present the antigens to T-cells, but also react rapidly by developing antimycobacterial immune response depending highly on the production of cytokines. However, Mtb is also capable of intracellular survival in instances of sub-optimal activation of macrophages. Hence, several systems have been established to evaluate the Mtb-macrophage interaction, where the THP-1 monocytes have been developed as an attractive model for in vitro polarized monocyte-derived macrophages. This model is extensively used for Mtb as well as other intracellular bacterial studies. Herein, we have summarized the updated implications of the THP-1 model for TB-related studies and discussed the pros and cons compared to other cell models of TB.

A Memorial Paper on Professor Takatsuki, Who Devoted Himself to the Case Report

This is a memorial paper for Prof [...]

Both Full-Length and Protease-Cleaved Products of Osteopontin Are Elevated in Infectious Diseases

Circulating full-length osteopontin (FL-OPN) is elevated in plasma from patients with various infectious diseases, such as adult T-cell leukemia, Mycobacterium tuberculosis (TB), hepatitis virus infection, leptospirosis, acquired immune deficiency syndrome (AIDS), AIDS/TB, and coronavirus disease 2019 (COVID-19). Proteolysis of OPN by thrombin, matrix metalloproteases, caspase 8/3, cathepsin D, plasmin, and enterokinase generates various cleaved OPNs with a variety of bioactivities by binding to different target cells. Moreover, OPN is susceptible to gradual proteolysis. During inflammation, one of the cleaved fragments, N-terminal thrombin-cleaved OPN (trOPN or OPN-Arg¹⁶⁸ [OPN-R]), induces dendritic cell (DC) adhesion. Further cleavage by carboxypeptidase B2 or carboxypeptidase N removes Arg¹⁶⁸ from OPN-R to OPN-Leu¹⁶⁷ (OPN-L). Consequently, OPN-L decreases DC adhesion. In particular, the differences in plasma level over time are observed between FL-OPN and its cleaved OPNs during inflammation. We found that the undefined OPN levels (mixture of FL-OPN and cleaved OPN) were elevated in plasma and reflected the pathology of TB and COVID-19 rather than FL-OPN. These infections are associated with elevated levels of various proteases. Inhibition of the cleavage or the activities of cleaved products may improve the outcome of the therapy. Research on the metabolism of OPN is expected to create new therapies against infectious diseases.

The extracellular matrix: A key player in the pathogenesis of hematologic malignancies

Hematopoietic stem and progenitor cells located in the bone marrow lay the foundation for multiple lineages of mature hematologic cells. Bone marrow niches are architecturally complex with specific cellular, physiochemical, and biomechanical factors. Increasing evidence suggests that the bone marrow microenvironment contributes to the pathogenesis of hematological neoplasms. Numerous studies have deciphered the role of genetic mutations and chromosomal translocations in the development hematologic malignancies. Significant progress has also been made in understanding how the cellular components and cytokine interactions within the bone marrow microenvironment promote the evolution of hematologic cancers. Although the extracellular matrix is known to be a key player in the pathogenesis of various diseases, it's role in the progression of hematologic malignancies is less understood. In this review, we discuss the interactions between the extracellular matrix and malignant cells, and provide an overview of the role of extracellular matrix remodeling in sustaining hematologic malignancies.

Stimulation of THP-1 Macrophages with LPS Increased the Production of Osteopontin-Encapsulating Exosome

Osteopontin (OPN) mediates bone remodeling and tissue debridement. The OPN protein is cleaved, but it is unclear how full-length (FL)-OPN or its cleaved form perform their biological activities in target cells. We, therefore, performed the molecular characterization of OPN in exosomes (Exo). The Exo were isolated from lipopolysaccharide (LPS)-stimulated phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages. The Exo were also isolated from PMA-differentiated THP-1 macrophages. The Exo were identified using the qNano multiple analyzer (diameter 59–315 nm) and western blotting with a CD9 antibody. LPS-stimulated cells produced more particles than non-stimulated cells. The presence of the FL or the cleaved form of OPN was confirmed using western blot analysis. A mixture of FL and cleaved OPN was also measured using an ELISA system (Ud-OPN) and their presence in the Exo was confirmed. Ud/FL ratios became low after LPS stimulation, indicating the enhanced encapsulation of FL-OPN in the Exo by LPS. These findings suggest that LPS stimulation of human macrophages facilitates the synthesis of FL-OPN, which is cleaved in cells or the Exo after release. These findings indicate that Exo is a suitable vehicle to transfer OPN to the target cells.

Synergy between parthenolide and arsenic trioxide in adult T-cell leukemia/lymphoma cells in vitro

OBJECTIVES

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive lymphoid malignancy with low survival rate and distinct geographical distribution. In search for novel chemotherapeutics against ATLL, we investigated the combinatorial effects of parthenolide, a sesquiterpene lactone with valuable pharmaceutical activities, and arsenic trioxide (ATO) in vitro.

MATERIALS AND METHODS

MT2 cells, an ATLL cell line, were treated with increasing concentrations of parthenolide (1.25, 2.5, and 5 μg/ml) and ATO (2, 4, 8, and 16 µM) to determine their IC50. Then, cells were treated with a combination of sub-IC50 concentrations of parthenolide (1 μg/ml) and ATO (2 µM) for 72 hr. Cell viability and cell cycle changes were assessed by Alamar blue and PI staining, respectively. To understand the mechanisms responsible for observed effects, expression of CD44, NF-κB (REL-A), BMI-1, and C-MYC were investigated by real-time PCR.

RESULTS

Assessment of cell viability indicated that parthenolide significantly increased the toxicity of ATO, as confirmed by accumulation of MT2 cells in the sub G1 phase of the cell cycle. Moreover, molecular analysis revealed significant down-regulation of CD44, NF-κB (REL-A), BMI-1, and C-MYC upon combinatorial administration of parthenolide and ATO in comparison with relevant controls.

CONCLUSION

Taken together, present results showed that parthenolide significantly enhanced the toxicity of ATO in MT2 cells. Therefore, the future possible clinical impact of our study could be combinatorial use of parthenolide and ATO as a novel and more effective approach for ATLL.

Osteopontin expression and its relationship with prognostic factors in diffuse large B-cell lymphoma

The aim of this study is to explore the expression of osteopontin (OPN) and its relationship with prognostic factors and survival in diffuse large B cell lymphoma (DLBCL). A tissue microarray was performed for immunohistochemical evaluation. Contingency tables were analyzed for trends; chi-square test was used to determine differences between groups. Univariate and multivariate Cox proportional hazards-regression analyses were performed to evaluate the impact of prognostic factors on survival. Expression of OPN was observed in 28%. It was different in non-germinal center DLBCL (P=0.04). The mean overall survival (OS) was lower in patients with positive OPN expression (19.762; CI 95% 14.269-25.255) it was not significant (P=0.123). It is not possible to establish a clear relationship between the expression by immunohistochemistry of osteopontin and a poor prognosis but it would be important to complement the analysis with other techniques as PCR or NGS that allow us to assess the influence of the isoforms and post-translational modifications of OPN on the biological behavior of DLBCL. Our findings indicate that OPN expression could be associated with a more aggressive variant of lymphoma: non-germinal center DLBCL.

Inhibition of inflammatory-molecule synthesis in THP-1 cells stimulated with phorbol 12-myristate 13-acetate by brefelamide derivatives

Plasma osteopontin (OPN) levels are elevated in tuberculosis patients and may involve granuloma formation. New inhibitors using brefelamide, an aromatic amide isolated from Dictyostelium cellular slime molds that may inhibit OPN transcription in A549 cells at 1 μM concentration, were synthesized as compounds C, D, and E. Their inhibitory activity against OPN synthesis in phorbol 12-myristate 13-acetate (PMA)-stimulated THP-1 cells was confirmed using enzyme-linked immunosorbent assay (ELISA), a multicolor immune-fluorescent microscope, and western blot. In the ELISA performed using full-length OPN, each compound showed significant inhibition in culture supernatants with half maximal inhibitory concentration (IC₅₀) values of 1.6, 1.8, and 2.2 μM for C, D, and E, respectively. In another ELISA to detect the immune-related form of OPN, IC₅₀ values were 0.6, 1.2, and 2.5 μM for compounds C, D, and E, respectively. The decreases in OPN expression and synthesis were confirmed using immunofluorescence and western blot studies using compound-treated cells or cell lysates. Luminex assay of the supernatants of PMA-treated THP-1 cells showed significant reduction in the synthesis of interleukin (IL)-1β, galectin-9, and tumor necrosis factor (TNF)-α. Elucidation of the detailed mechanisms of the biological activities of these compounds would be necessary; however, they may be used in clinical trials for infectious diseases, inflammatory disorders, and cancer.

Successful Amplified-Natural-Killer Cell (ANK) Therapy Administered to a Patient with Smoldering Adult T-Cell Leukemia in Acute Crisis

Adult T-cell leukemia (ATL) is an indolent leukemia caused by type 1 human T-cell leukemia virus (HTLV-1). A variety of therapeutic interventions via immunological approaches have been attempted. ATL cells express costimulatory molecules of natural killer (NK) cells, and a new modality—amplified NK (ANK) cell treatment—was administered here to a patient with ATL. A 70-year-old female presenting with ringworm infection received a diagnosis of smoldering ATL in 2004. Monitoring of soluble IL-2 receptors (sIL-2Rs) in the serum showed disease exacerbation in 2007, associated with the enlargement of lymph nodes and formation of a skin tumor. NK cells were amplified by in vitro cell culture methods. To avoid cytokine release syndrome, 2–5 × 108 cells were administered with each injection. A total of 15 injections from 12 November 2007 to 15 February 2008 were administered to this patient. This case showed drastic downregulation of sIL-2R, resulting in the induction of complete remission, which lasted for >5 years. This is the first report of treatment of a patient with ATL using ANK cell therapy. More attempts of this therapy will enhance our insight into the appropriate application of this new therapy to clinically diverse 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.

Synthesis of a Cleaved Form of Osteopontin by THP-1 Cells and Its Alteration by Phorbol 12-Myristate 13-Acetate and BCG Infection

The protease-cleaved osteopontin (OPN) was proposed to enhance the migration of memory T cells to granulomas in tuberculosis. Various forms of OPN were identified in human monocytic THP-1 cells stimulated by phorbol 12-myristate 13-acetate (PMA). Antibodies O-17, 10A16 and 34E3, which recognize N-terminus, the C-half, and thrombin-cleaved site of OPN, respectively, all detected distinct bands on Western blots following PMA stimulation. Bands corresponding to 18 and 30 kD were detected by antibodies 34E3 and 10A16, indicating that OPN cleavage occurred by endogenous proteases in the PMA-stimulated THP-1 cells. In immune-fluorescence (IF) assay, 34E3 positive signals were detected in intracellular space of non-infected and bacillus Calmette-Guérin (BCG)-infected cells; however, 10A16 positive signals were confirmed in extracellular area in PMA-stimulated cells followed by BCG infection. Small amounts of full-length (FL) and thrombin-cleaved (Tr) OPN were detected by ELISA in the supernatants of non-PMA-stimulated cells, and increased levels of all forms, including undefined (Ud) OPN, in PMA-stimulated cells. ELISA showed a decrease in OPN synthesis during BCG infection. To our knowledge, this is the first report of OPN cleavage in THP-1 macrophages after PMA stimulation, and of enhanced cleavage induced by BCG infection.

The Roles of Matricellular Proteins in Oncogenic Virus-Induced Cancers and Their Potential Utilities as Therapeutic Targets

Matricellular proteins differ from other classical extracellular matrix proteins; for instance, they are transiently expressed as soluble proteins rather than being constitutively expressed in pathological conditions, such as acute viral infections. Accumulating studies have revealed that matricellular proteins, including osteopontin and tenascin-C, both of which interact with integrin heterodimers, are involved in inflammatory diseases, autoimmune disorders, and cancers. The concentrations of these matricellular proteins are elevated in the plasma of patients with certain types of cancers, indicating that they play important roles in oncogenesis. Chronic viral infections are associated with certain cancers, which are distinct from non-viral cancers. Viral oncogenes play critical roles in the development and progression of such cancers. It is vital to investigate the mechanisms of tumorigenesis and, particularly, the mechanism by which viral proteins induce tumor progression. Viral proteins have been shown to influence not only the viral-infected cancer cells, but also the stromal cells and matricellular proteins that constitute the extracellular matrix that surrounds tumor tissues. In this review, we summarize the recent progress on the involvement of matricellular proteins in oncogenic virus-induced cancers to elucidate the mechanism of oncogenesis and consider the possible role of matricellular proteins as therapeutic targets in virus-induced cancers.

Osteopontin and their roles in hematological malignancies: Splice variants on the new avenues

Osteopontin (OPN) is a protein expressed in several tissues, including bone marrow, in which it performs distinct roles, such as modulating hematopoietic stem cell niche and bone remodeling. Most data in hematological malignancies (HMs) refers to total OPN (tOPN), comprehending the sum of distinct OPN splicing isoforms (OPN-SI), while reports describing the expression and roles of each OPN-SI are scarce. This review aims to summarize tOPN roles in HMs and provide evidence that OPN-SIs can also modulate specific functions in HMs biology. We summarize that upregulated tOPN can modulate HMs (leukemia, lymphoma and myeloma) progression, inducing cell adhesion, invasion, angiogenesis, cell differentiation and extramedullary and/or central nervous system infiltration. Based on this expression pattern, tOPN has been pointed out as a biomarker in those HMs, thus providing potential targets for therapeutic approaches. Our group found that OPN-SIs are expressed in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cell lines (unpublished data), providing early evidence that OPN-SIs are also expressed in BCP-ALL. Further studies should investigate whether these OPN-SIs can differently modulate HMs biology and their putative application as auxiliary biomarkers for HMs.

Galectin-9 as a Predictive Marker for the Onset of Immune-Related Adverse Effects Associated with Anti-CCR4 MoAb Therapy in Patients with Adult T Cell Leukemia

Adult T-cell leukemia/lymphoma (ATL/ATLL) is one of the most malignant lymphomas with poor prognosis. ATL/ATLL cells express CC chemokine receptor 4, and mogamulizumab (anti-CCR4 monoclonal antibody) exhibits strong cytotoxicity for ATL/ATLL cells. We analyzed plasma samples of 6 patients with ATL/ATLL treated with chemotherapy followed by mogamulizumab therapy (mogatherapy) for changes in the levels of biomarkers in relation to immune-related adverse effects. As treatment is often associated with skin eruptions, we investigated the profiles of inflammatory cytokines, including galectin-9 (Gal-9), which becomes increased in various infectious diseases and allergic patients. Gal-9, soluble interleukin (IL)-2 receptor, tumor necrosis factor-α, and IL-10 levels were increased before chemotherapy, and Gal-9 levels were associated with the sIL-2 receptor, which reflects tumor burden. Inflammatory levels decreased after chemotherapy. After mogatherapy, 5 of 6 patients attained complete remission (CR), whereas 1 patient showed no response (NR) and died. Among 5 patients with CR, the biomarkers remained low during mogatherapy, except for a 3-5-fold increment in Gal-9 (associated with skin eruptions). A skin biopsy showed infiltration by inflammatory cells and Gal-9 synthesis in areas with CD8 cell infiltration. In the patient with NR, increased levels of Gal-9 and the aforementioned biomarkers were noted 3 days after mogatherapy, followed by opportunistic infections resembling immune reconstitution inflammatory syndrome. Therefore, an increased Gal-9 plasma level in ATL/ATLL indicates tumor burden and reflects immune activation by mogatherapy. These findings may indicate that an increase in the Gal-9 level, a novel immune checkpoint molecule, can reflect immune-related adverse effects of various biotherapies.

Secretion of IFN-γ Associated with Galectin-9 Production by Pleural Fluid Cells from a Patient with Extrapulmonary Tuberculosis

In this study, we investigated the role of a matricellular protein galectin-9 (Gal-9) in pleural effusion related to tuberculosis (TB). Plasma and pleural fluid of a patient with extrapulmonary TB were analyzed for cytokine content by ELISA and Luminex. Peripheral blood mononuclear cells (PBMCs) and pleural fluid cells (PFCs) were examined for interferon-γ (IFN-γ) secretion by the enzyme-linked immunospot (ELISPOT) assay or IFN-γ ELISA, for apoptosis and necrosis by Cell Death Detection ELISA, and also underwent cell sorting. The results indicate that compared to plasma, pleural fluid had increased levels of IFN-γ (1.6 vs. 55.5 pg/mL), IL-10, IL-12p40, vascular endothelial growth factor (VEGF), and Gal-9 (3.0 vs. 936.0 pg/mL), respectively. PFCs culture supernatant exhibited higher concentration of Gal-9 compared to PBMCs in culture, consistent with enriched Gal-9 staining in the granuloma that is in closer vicinity to PFCs compared to PBMCs. PFCS displayed higher IFN-γ secretion after stimulation with TB antigens ESAT-6/CFP-10. Furthermore, in PFCs, Gal-9 alone could stimulate IFN-γ synthesis in culture or ELISPOT, which was inhibited by a Gal-9 antagonist lactose, and which may promote apoptosis and necrosis. These findings suggest that Gal-9 could modulate immune responses and participate in immunopathology of pleural effusion during TB.

Prognostic significance of osteopontin in acute myeloid leukemia: A meta-analysis

Osteopontin (OPN) has been investigated in the field of tumor research for several years. However, the prognostic role of OPN overexpression in acute myeloid leukemia (AML) remains controversial. A meta-analysis of four studies, including a total of 492 patients, was performed to determine the association of OPN with overall survival (OS) in AML patients. The random-effects model of Der Simonian and Laird was used to synthesize data; hazard ratio (HR) with its 95% confidence interval (CI) was used as the effect size estimate. It was observed that serum-based OPN was inversely correlated with OS and the difference was statistically significant (HR=1.83; 95% CI: 1.43-2.35; P<0.001). Experimental findings indicate that OPN overexpression is associated with a poor prognosis in AML and may be of prognostic value for AML stage and metastasis.

Crucial role of carbonic anhydrase IX in tumorigenicity of xenotransplanted adult T-cell leukemia-derived cells

Carbonic anhydrase IX (CA9) is a membrane‐associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T‐cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1‐N6 subline from the ATL‐derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1‐N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1‐CA9^high and ST1‐CA9^low sublines. ST1‐CA9^high cells, like ST1‐N6 cells, were more strongly tumorigenic than ST1‐CA9^low or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1‐CA9^high cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild‐type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9⁺CD25⁺ cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL‐derived cells and may be involved in malignant development of lymphoma‐type ATL.

Induction of Osteopontin by Dengue Virus-3 Infection in THP-1 Cells: Inhibition of the Synthesis by Brefelamide and Its Derivative

Osteopontin (OPN) is a multifunctional matricellular protein produced by a broad range of cells including osteoclasts, macrophages, T cells, endothelial cells, and vascular smooth muscle cells. OPN modulates various physiological and pathological events such as inflammation, wound healing, and bone formation and remodeling. Dengue virus (DENV) infection causes an increase in plasma OPN levels, which is correlated with the severity of symptoms and coagulation abnormalities. DENV infection also induces OPN gene expression in human macrophages. This study investigated the inhibitory effects of brefelamide and its methyl ether derivative on DENV-3 by measuring changes in OPN levels in human THP-1 and 293T cell lines infected at different multiplicities of infection and post-infection time points. OPN mRNA expression and viral RNA were detected by reverse transcriptase quantitative real-time PCR, whereas protein level was determined by enzyme-linked immunosorbent assay. We found that viral copy number was higher in 293T than in THP-1 cells. However, THP-1 constitutively expressed higher levels of OPN mRNA and protein, which were enhanced by DENV-3 infection. Brefelamide and its derivative suppressed OPN production in DENV-3 infected THP-1 cells; the effective doses of these compounds had no effect on uninfected cells, indicating low cytotoxicity. These results suggest that brefelamide and its methyl ether derivative have therapeutic effects in preventing inflammation, coagulopathy, and fibrinolysis caused by OPN upregulation induced by DENV-3 infection.

Immunological Roles of Elevated Plasma Levels of Matricellular Proteins in Japanese Patients with Pulmonary Tuberculosis

Elevated matricellular proteins (MCPs), including osteopontin (OPN) and galectin-9 (Gal-9), were observed in the plasma of patients with Manila-type tuberculosis (TB) previously. Here, we quantified plasma OPN, Gal-9, and soluble CD44 (sCD44) by enzyme-linked immunosorbent assay (ELISA), and another 29 cytokines by Luminex assay in 36 patients with pulmonary TB, six subjects with latent tuberculosis (LTBI), and 19 healthy controls (HCs) from Japan for a better understanding of the roles of MCPs in TB. All TB subjects showed positive results of enzyme-linked immunospot assays (ELISPOTs). Spoligotyping showed that 20 out of 36 Mycobacterium tuberculosis (MTB) strains belong to the Beijing type. The levels of OPN, Gal-9, and sCD44 were higher in TB (positivity of 61.1%, 66.7%, and 63.9%, respectively) than in the HCs. Positive correlations between OPN and Gal-9, between OPN and sCD44, and negative correlation between OPN and ESAT-6-ELISPOT response, between chest X-ray severity score of cavitary TB and ESAT-6-ELISPOT response were observed. Instead of OPN, Gal-9, and sCD44, cytokines G-CSF, GM-CSF, IFN-α, IFN-γ, IL-12p70, and IL-1RA levels were higher in Beijing MTB-infected patients. These findings suggest immunoregulatory, rather than inflammatory, effect of MCPs and can advance the understanding of the roles of MCPs in the context of TB pathology.

Role of osteopontin in lung cancer evolution and heterogeneity

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

Evaluation of matricellular proteins in systemic and local immune response to Mycobacterium tuberculosis infection

Matricellular proteins such as osteopontin (OPN), galectin-9 (Gal-9), and tenascin-C (TN-C) are expressed not only under normal physiological conditions, but also during infection, inflammation and tumorigenesis. Plasma concentrations of matricellular proteins were studied to determine their diagnostic value as potential markers of tuberculosis (TB) activity. It was found that concentrations of OPN and TN-C were higher in patients with active TB than in healthy controls and individuals with latent infection. Moreover, LTBI patients had higher concentrations of OPN than did healthy controls. Gal-9 concentrations did not differ significantly between groups. Concentrations of matricellular proteins were higher in pleural fluid than in the plasma of patients with TB. Expression of matricellular proteins was also investigated in TB granulomas and other granulomatous diseases. Positive OPN and Gal-9 staining was observed in TB and sarcoidosis granulomas, but not in Crohn disease granulomas. The fibrotic ring around granulomas stained positive for TN-C in TB and sarcoidosis, but not in Crohn disease. Of the three matricellular proteins studied, OPN and TN-C may serve as reliable plasma markers for monitoring TB activity, whereas Gal-9 seems to be expressed more at the site of infection than in the systemic circulation.

Concurrent Elevations of VEGF, Osteopontin and MCP-1 Serum Levels Are Independent Predictors of Survival in Patients with Diffuse Large B-Cell Lymphoma

BACKGROUND

Diffuse large B-cell lymphomas (DLBCL) are heterogeneous diseases, and the identification of additional DLBCL risk factors is especially important.

METHODS

In this pilot study, we determined pretreatment serum levels of vascular endothelial growth factor (VEGF), osteopontin (OPN) and macrophage chemotactic protein-1 (MCP-1) in 67 newly diagnosed DLBCL patients before treatment with standard chemoimmunotherapy and in 30 healthy persons.

RESULTS

Serum levels of all three cytokines were significantly elevated in untreated patients compared to controls. VEGF and OPN concentrations were higher in patients with advanced Ann Arbor stage, B symptoms, Eastern Cooperative Oncology Group score ≥2, International Prognostic Index (IPI) ≥3 and partial/no remission. A high MCP-1 level was associated with advanced stage, increased IPI and bone marrow infiltration. In univariate analysis, elevated OPN and VEGF, and concurrent elevation of all three biomarkers, were identified as significant predictors of poor survival. Multivariate Cox analysis revealed that elevated OPN combined with elevated VEGF levels was one of the best parameter subsets predicting poorest survival.

CONCLUSION

According to our preliminary results, serum levels of VEGF and OPN before treatment predict response to therapy and survival after chemoimmunotherapy, and may help to further stratify DLBCL patients into risk groups.

Osteopontin-integrin interaction as a novel molecular target for antibody-mediated immunotherapy in adult T-cell leukemia

Background

Adult T-cell leukemia (ATL) is a CD4⁺ T-cell neoplasm with a poor prognosis. A previous study has shown that there is a strong correlation between the secreted matricellular protein osteopontin (OPN) level and disease severity in ATL patients. Here, we investigated the role of OPN in ATL pathogenesis and the possible application of anti-OPN monoclonal antibody (mAb) for ATL immunotherapy in NOD/Shi-scid,IL-2Rg^null (NOG) mice.

Results

Subcutaneous inoculation of ATL cell lines into NOG mice increased the plasma level of OPN, which significantly correlated with metastasis of the inoculated cells and survival time. Administration of an SVVYGLR motif-recognizing anti-OPN mAb resulted in inhibition not only of tumor growth but also of tumor invasion and metastasis. The number of fibroblast activating protein-positive fibroblasts was also reduced by this mAb. We then co-inoculated mouse embryonic fibroblasts (MEFs) isolated from wild-type (WT) or OPN knockout mice together with ATL-derived TL-OmI cells into the NOG mice. The mice co-inoculated with WT MEFs displayed a significant decrease in survival relative to those injected with TL-OmI cells alone and the absence of OPN in MEFs markedly improved the survival rate of TL-OmI-inoculated mice. In addition, tumor volume and metastasis were also reduced in the absence of OPN.

Conclusion

We showed that the xenograft NOG mice model can be a useful system for assessment of the physiological role of OPN in ATL pathogenesis. Using this xenograft model, we found that fibroblast-derived OPN was involved in tumor growth and metastasis, and that this tumor growth and metastasis was significantly suppressed by administration of the anti-OPN mAbs. Our findings will lead to a novel mAb-mediated immunotherapeutic strategy targeting against the interaction of OPN with integrins on the tumor of ATL patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0225-x) contains supplementary material, which is available to authorized users.

Anchorage-dependent multicellular aggregate formation induces CD44 high cancer stem cell-like ATL cells in an NF-κB- and vimentin-dependent manner

Adult T-cell leukemia/lymphoma (ATL) is an intractable T-cell malignancy accompanied by massive invasion of lymphoma cells into various tissues. We demonstrate here that ATL cells cultured on a layer of epithelial-like feeder cells form anchorage-dependent multicellular aggregates (Ad-MCAs) and that a fraction of MCA-forming ATL cells acquire CD44 high cancer stem cell-like phenotypes. ATL cells forming Ad-MCAs displayed extracellular microvesicles with enhanced expression of CD44v9 at cell synapses, augmented expression of multidrug resistance protein 1, and increased NF-κB activity. Blockade of the NF-κB pathway dramatically reduced Ad-MCA formation by ATL cells and the emergence of CD44 high ATL cells, but left a considerable number of ATL cells adhering to the feeder layer. Disruption of vimentin cytoskeleton by treatment with withaferin A, a natural steroidal lactone, suppressed not only the adhesion of ATL cells to the feeder layer but also subsequent Ad-MCA formation by ATL cells, suggesting the involvement of vimentin in anchoring ATL cells to the feeder layer. Ad-MCA formation by ATL cells on a layer of epithelial-like feeder cells may mimic critical events that occur in metastatic colonization.

Role of osteopontin in the pathophysiology of cancer

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

Elevated levels of full-length and thrombin-cleaved osteopontin during acute dengue virus infection are associated with coagulation abnormalities

INTRODUCTION

Dengue virus (DENV) is transmitted by the mosquito vector, and causes a wide range of symptoms that lead to dengue fever (DF) or life-threatening dengue hemorrhagic fever (DHF). The host and viral correlates that contribute to DF and DHF are complex and poorly understood, but appear to be linked to inflammation and impaired coagulation. Full-length osteopontin (FL-OPN), a glycoprotein, and its activated thrombin-cleaved product, trOPN, integrate multiple immunological signals through the induction of pro-inflammatory cytokines.

MATERIALS AND METHOD

To understand the role of OPN in DENV-infection, we assessed circulating levels of FL-OPN, trOPN, and several coagulation markers (D-dimer, thrombin-antithrombin complex [TAT], thrombomodulin [TM], and ferritin in blood obtained from 65 DENV infected patients in the critical and recovery phases of DF and DHF during a dengue virus epidemic in the Philippines in 2010.

RESULTS

Levels of FL-OPN, trOPN, D-dimer, TAT, and TM were significantly elevated in the critical phase in both the DF and DHF groups, as compared with healthy controls. During the recovery phase, FL-OPN levels declined while trOPN levels increased dramatically in both the DF and DHF groups. FL-OPN levels were directly correlated with D-dimer and ferritin levels, while the generation of trOPN was associated with TAT levels, platelet counts, and viral RNA load.

CONCLUSION

Our study demonstrated the marked elevation of plasma levels of FL-OPN and thrombin-cleaved OPN product, trOPN, in DENV-infection for the first time. Further studies on the biological functions of these matricellular proteins in DENV-infection would clarify its pathogenesis.

Effects and mechanisms of curcumin and basil polysaccharide on the invasion of SKOV3 cells and dendritic cells

In the present study, a polysaccharide extract was obtained from Ocimum basilicum (basil polysaccharide, BPS) and the effects of curcumin and BPS on the invasion activity of the SKOV3 ovarian cancer cells and human monocyte-derived dendritic cells (DCs) were investigated. SKOV3 cells and immature or mature DCs were treated with 50 µM curcumin or 100 µg/ml BPS. A transwell invasion assay demonstrated that curcumin and BPS differentially regulate the invasion of SKOV3 cells and DCs. Curcumin significantly decreased the invasion of SKOV3 cells and immature and mature DCs, while BPS only decreased SKOV3 cell invasion. Osteopontin (OPN) mRNA and protein expression were significantly reduced in curcumin and BPS-treated SKOV3 cells and curcumin-treated DCs. Furthermore, flow cytometry showed that curcumin significantly inhibited the surface expression of CD44 in SKOV3 cells and DCs, while BPS had a minimal effect on CD44 expression. Matrix metallopeptidase-9 (MMP-9) mRNA and protein expression were also reduced in all curcumin-treated cells and BPS-treated SKOV3 cells. The results indicated that curcumin and BPS regulated invasion of SKOV3 cells and DCs by distinctly downregulating OPN, CD44 and MMP-9 expression. Therefore, Curcumin and BPS may be suitable candidates for DC-based vaccines for ovarian cancer immunotherapy.

Protective roles of epithelial cells in the survival of adult T-cell leukemia/lymphoma cells

Adult T-cell leukemia/lymphoma (ATL) is a highly invasive and intractable T-cell malignancy caused by human T-cell leukemia virus-1 infection. We demonstrate herein that normal tissue-derived epithelial cells (NECs) exert protective effects on the survival of leukemic cells, which may partially account for high resistance to antileukemic therapies in patients with ATL. Viral gene-silenced, ATL-derived cell lines (ATL cells) dramatically escaped from histone deacetylase inhibitor-induced apoptosis by direct co-culture with NECs. Adhesions to NECs suppressed p21(Cip1) expression and increased a proportion of resting G0/G1 phase cells in trichostatin A (TSA)-treated ATL cells. ATL cells adhering to NECs down-regulated CD25 expression and enhanced vimentin expression, suggesting that most ATL cells acquired a quiescent state by cell-cell interactions with NECs. ATL cells adhering to NECs displayed highly elevated expression of the cancer stem cell marker CD44. Blockade of CD44 signaling diminished the NEC-conferred resistance of ATL cells to TSA-induced apoptosis. Co-culture with NECs also suppressed the expression of NKG2D ligands on TSA-treated ATL cells, resulting in decreased natural killer cell-mediated cytotoxicity. Combined evidence suggests that interactions with normal epithelial cells augment the resistance of ATL cells to TSA-induced apoptosis and facilitate immune evasion by ATL cells.

Rapid decrease of plasma galectin-9 levels in patients with acute HIV infection after therapy

Acute HIV-1 infection is often diagnosed as infectious mononucleosis and the symptoms resolve spontaneously after varying periods of time. After the infection of HIV-1 through the mucosa, the characteristic clinical symptoms and laboratory markers of acute HIV-1 infection appear in each patient through a complicated virus-host interaction. To understand the host responses, we measured two unique proinflammatory cytokines, galectin-9 (Gal-9) and osteopontin (OPN). A β-galactoside-binding mammalian lectin, Gal-9, reduces pro-inflammatory type-1 helper T (Th1) cells and Th17 cells and increases anti-inflammatory regulatory T cells. The plasma level of Gal-9 is known to be associated with HIV-1 viral load in chronic HIV-1 infection. On the contrary, osteopontin induces Th1/Th17 cells and promotes tissue inflammation. OPN is synthesized by variety of cells in the body, and dendritic cells are known to synthesize OPN in HIV-1 infected individuals. It was hypothesized that Gal-9 and/or OPN could be not only immune-modulators but also novel biomarkers of acute HIV-1 infection. We experienced 3 patients with acute HIV-1 and measured the levels of Gal-9 and OPN periodically before and after antiretroviral treatment. The results showed that the plasma levels of Gal-9 were extremely elevated [more than 2,300 pg/ml (normal range < 46 pg/ml)] in all three acute HIV-1 infected individuals and decreased rapidly after treatment. The changes in the OPN levels were less marked. In conclusion, the plasma levels of Gal-9 may be predictive of a severe inflammation status during the acute phase of HIV-1 infection and could be a potential biomarker during acute infection.

Frequent detection of anti-tubercular-glycolipid-IgG and -IgA antibodies in healthcare workers with latent tuberculosis infection in the Philippines

Anti-tubercular-glycolipid-IgG (TBGL-IgG) and -IgA (TBGL-IgA) antibodies, and the QuantiFERON-TB Gold test (QFT) were compared in healthcare workers (HCWs, n = 31) and asymptomatic human immunodeficiency virus-carriers (HIV-AC, n = 56) in Manila. In HCWs, 48%, 51%, and 19% were positive in QFT, TBGL-IgG, and -IgA, respectively. The TBGL-IgG positivity was significantly higher (P = 0.02) in QFT-positive than QFT-negative HCWs. Both TBGL-IgG- and -IgA-positive cases were only found in QFT-positive HCWs (27%). The plasma IFN-γ levels positively correlated with TBGL-IgA titers (r = 0.74, P = 0.005), but not TBGL-IgG titers in this group, indicating that mucosal immunity is involved in LTBI in immunocompetent individuals. The QFT positivity in HIV-AC was 31% in those with CD4+ cell counts >350/μL and 12.5% in low CD4 group (<350/μL). 59 % and 29% were positive for TBGL-IgG and -IgA, respectively, in HIV-AC, but no association was found between QFT and TBGL assays. TBGL-IgG-positive rates in QFT-positive and QFT-negative HIV-AC were 61% and 58%, and those of TBGL-IgA were 23% and 30%, respectively. The titers of TBGL-IgA were associated with serum IgA (P = 0.02) in HIV-AC. Elevations of TBGL-IgG and -IgA were related to latent tuberculosis infection in HCWs, but careful interpretation is necessary in HIV-AC.