The M1/M2 macrophage paradigm plays a key role in tumor progression. M1 macrophages are historically regarded as anti-tumor, while M2-polarized macrophages, commonly deemed tumor-associated macrophages (TAMs), are contributors to many pro-tumorigenic outcomes in cancer through angiogenic and lymphangiogenic regulation, immune suppression, hypoxia induction, tumor cell proliferation, and metastasis. The tumor microenvironment (TME) can influence macrophage recruitment and polarization, giving way to these pro-tumorigenic outcomes. Investigating TME-induced macrophage polarization is critical for further understanding of TAM-related pro-tumor outcomes and potential development of new therapeutic approaches. This review explores the current understanding of TME-induced macrophage polarization and the role of M2-polarized macrophages in promoting tumor progression.

A variety of nonmalignant cells present in the tumor microenvironment promotes tumorigenesis by stimulating tumor cell growth and metastasis or suppressing host immunity. The role of such stromal cells in T-cell lymphoproliferative disorders is incompletely understood. Monocyte-derived cells (MDCs), including professional antigen-presenting cells such as dendritic cells (DCs), play a central role in T-cell biology. Here, we provide evidence that monocytes promote the survival of malignant T cells and demonstrate that MDCs are abundant within the tumor microenvironment of T cell-derived lymphomas. Malignant T cells were observed to remain viable during in vitro culture with autologous monocytes, but cell death was significantly increased after monocyte depletion. Furthermore, monocytes prevent the induction of cell death in T-cell lymphoma lines in response to either serum starvation or doxo-rubicin, and promote the engraftment of these cells in nonobese diabetic/severe combined immunodeficient mice. Mono-cytes are actively recruited to the tumor microenvironment by CCL5 (RANTES), where their differentiation into mature DCs is impaired by tumor-derived interleukin-10. Collectively, the data presented demonstrate a previously unde-scribed role for monocytes in T-cell lym-phoproliferative disorders. (Blood. 2009;

Heparan sulfate proteoglycans (HSPGs) act as coreceptors or storage sites for growth factors and cytokines such as fibroblast growth factor and Wnts. Glypican 3 (GPC3) is the most highly expressed HSPG in hepatocellular carcinoma (HCC). Sulfatase 2 (SULF2), an enzyme with 6-O-desulfatase activity on HSPGs, is up-regulated in 60% of primary HCCs and is associated with a worse prognosis. We have previously shown that the oncogenic effect of SULF2 in HCC may be mediated in part through up-regulation of GPC3. Here we demonstrate that GPC3 stimulates the Wnt/b-catenin pathway and mediates the oncogenic function of SULF2 in HCC. Wnt signaling in vitro and in vivo was assessed in SULF2-negative Hep3B HCC cells transfected with SULF2 and in SULF2-expressing Huh7 cells transfected with short hairpin RNA targeting SULF2. The interaction between GPC3, SULF2, and Wnt3a was assessed by coimmunoprecipitation and flow cytometry. bcatenin-dependent transcriptional activity was assessed with the TOPFLASH (T cell factor reporter plasmid) luciferase assay. In HCC cells, SULF2 increased cell surface GPC3 and Wnt3a expression, stabilized b-catenin, and activated T cell factor transcription factor activity and expression of the Wnt/b-catenin target gene cyclin D1. Opposite effects were observed in SULF2-knockdown models. In vivo, nude mouse xenografts established from SULF2-transfected Hep3B cells showed enhanced GPC3, Wnt3a, and b-catenin levels. Conclusion: Together, these findings identify a novel mechanism mediating the oncogenic function of SULF2 in HCC that includes GPC3-mediated activation of Wnt signaling via the Wnt3a/glycogen synthase kinase 3 beta axis.

Although proinflammatory and chemotactic cytokines can profoundly affect the tumor microenvironment, and many of them have been shown to have therapeutic efficacy in preclinical models, the role of these molecules in Waldenströ m macroglobulinemia (WM) remains poorly understood. In this study, simultaneous analysis of WM patient sera and bone marrow biopsies identified a set of dysregulated cytokines including CCL5, G-CSF, and soluble IL-2 receptor, that were significantly elevated in WM patients whereas IL-8 and EGF levels were significantly lower in these patients compared with healthy controls. Interestingly, CCL5 levels positively correlated with features of disease aggressiveness such as elevated IgM levels and bone marrow involvement. IntroductionCytokines are protein mediators that are known to be involved in many biologic processes including cell growth, survival, inflammation, and differentiation. [1][2][3] In the malignant scenario, cytokines can profoundly affect tumor cells directly as well as the surrounding microenvironment, thereby impacting tumor cell biology. Therefore, understanding the composition of the cytokine milieu, particularly in the tumor microenvironment, is an important component of our understanding of the biology of malignant transformation. Targeting cytokines has been shown to have potent therapeutic efficacy in preclinical cancer models. 4,5 Despite the importance of cytokine networks in normal and disease states, only a limited number of studies have addressed the role of cytokines in the regulation of the tumor microenvironment in B-cell malignancies, and in particular, Waldenström macroglobulinemia (WM).WM is characterized by an infiltration of lymphoplasmacytic cells in the bone marrow accompanied by a high circulating monoclonal IgM protein that often leads to serum hyperviscosity. 6 Despite the introduction of multiple therapies, WM remains an incurable disease. Therefore, an understanding of the basic mechanisms underlying disease biology is fundamental to the development of novel therapies. In this study, we used a multiplex immunobead assay to simultaneously measure cytokines, chemokines, angiogenic factors, as well as growth factors and soluble receptors in the sera of WM patients and compared them with healthy donors. Our studies identify CCL5 (also known as regulated on activation, normal T-cell expressed, and secreted [RAN-TES]), G-CSF, and soluble IL-2 receptor ␣ (sIL-2R/CD25) as highly expressed in WM patient sera whereas IL-8 and EGF are down-regulated. Further analysis of CCL5 found that serum CCL5 levels correlated with expression of CCL5 in the bone marrow, IgM, IL-6 and bone marrow involvement by lymphoplasmacytic cells. Further analysis of the interplay between CCL5 and IL-6 indicated that CCL5 induced IL-6 secretion by WM stromal cells and identified the JAK/STAT signaling pathway as a mediator of IgM secretion in response to IL-6 stimulation. Therefore, therapies targeting CCL5 may provide therapeutic efficacy for WM patients by reducing IL-6 secretion by...

Tumor cells interact with their surrounding microenvironment to survive and persist within the host. Cytokines play a key role in regulating this crosstalk between malignant cells and surrounding cells in the microenvironment. Although this phenomenon is clearly established, the molecular mechanisms mediating this cellular event remain elusive. Here, using as a model bone marrow stromal cells, we describe a novel signaling mechanism initiated by CCL5 in these cells leading to up-regulation of immunoglobulin secretion by malignant B cells. CCL5 increases IL-6 expression and secretion in bone marrow stromal cells. IL-6 in turn induces Ig secretion by malignant B cells. Analysis of the mechanism reveals that CCL5 signaling induces GLI2 through a PI3K-AKT-IB␣-p65 pathway and requires GLI2 transcriptional activity to modulate IL-6 expression and Ig secretion in vitro and in vivo. Together, these results identify a novel signaling pathway mediating the stromal-cancer cell interactions, leading to increased Ig production by malignant cells.

Early IFN-α/β production, followed by the development of a viral-specific CTL response, are critical factors in limiting the level of murine γ-herpesvirus-68 (γHV-68) infection. Development of a long-lived CTL response requires T cell help, and these CTLs most likely function to limit the extent of infection following reactivation. The importance of IL-12 in the development and/or activity of Th1 cells and CTLs is well documented, and we investigated the kinetics and magnitude of γHV-68-induced IL-12 production. Following intranasal infection, IL-12 and IL-23 mRNA expression was up-regulated in lung and spleen and lung, respectively, followed by increased levels of IL-12p40 in lung homogenates and sera. Exposure of cultured macrophages or dendritic cells to γHV-68 induced secretion of IL-12, suggesting that these cells might be responsible for IL-12 production in vivo. γHV-68 infection of mice made genetically deficient in IL-12p40 expression (IL-12p40−/−) resulted in a leukocytosis and splenomegaly that was significantly less than that observed in syngeneic C57BL/6 mice. IL-12p40−/− mice showed increased levels of infectious virus in the lung, but only at day 9 postinfection. Increased levels of latent virus in the spleen at day 15 postinfection were also observed in IL-12p40−/− mice when compared with syngeneic C57BL/6 mice. An overall reduction in γHV-68-induced IFN-γ production was observed in IL-12p40−/− mice, suggesting that most of the viral-induced IFN-γ in C57BL/6 mice was IL-12 dependent. Taken together, these results suggest that γHV-68-induced IL-12 contributes to the pathophysiology of viral infection while also functioning to limit viral burden.

Background: Autophagy plays a role in cancer development. Results: Oncogenic KRAS induces Vacuole Membrane Protein 1 (VMP1) through a novel AKT1-GLI3-p300 pathway and requires VMP1 to regulate autophagy in cancer cells. Conclusion: Define a novel pathway initiated by the oncogene KRAS regulating autophagy. Significance: These findings contribute to the understanding of the mechanism underlying oncogene-induced autophagy.

Double/triple-hit lymphomas (DHL/THL) account for 5–10% of diffuse large B cell lymphoma (DLBCL) with rearrangement of MYC and BCL2 and/or BCL6 resulting in MYC overexpression. Despite the poor prognosis of DHL, R-CHOP chemotherapy remains the treatment backbone and new targeted therapy is needed. We performed comprehensive cytogenetic studies/fluorescence in situ hybridization on DLBCL and Burkitt lymphoma cell lines ( n = 11) to identify the DHL/THL DLBCL in vitro model. We identified MYC/IG in Raji and Ramos (single hit); MYC/IG-BCL2 (DHL) in DOHH2, OCI-LY1, SUDHL2, and OCI-LY10; MYC/IG-BCL2/BCL6 (THL) in VAL; and no MYC rearrangement in U2932 and HBL1 (WT-MYC). Targeting MYC in the DHL/THL DLBCLs through bromodomain extra-terminal inhibitors (BETi) (JQ1, I-BET, and OTX015) significantly ( p < 0.05) reduced proliferation, similar to WT-MYC cells, accompanied by decreased MYC but not BCL2 protein. Moreover, BETi suppressed MYC transcription and decreased BRD4 binding to MYC promoter in DHL cells. CD47 and PD-L1 are immunoregulatory molecules often expressed on tumors and regulated by MYC . High levels of surface CD47 but not surface PD-L1 was observed in DHL/THL, which was reduced by JQ1 treatment. BETi in combination with Pan-HDAC inhibitor had a limited effect on survival of DHL/THL, while combination of BETi and BCL2 inhibitor (ABT-199) had a significant ( p < 0.005) inhibitory effect on survival followed by BCL-XL inhibition. Overall, the data suggests that MYC-expressing DLBCLs are probably addicted to the MYC-oncogenic effect regardless of MYC rearrangements. In summary, we identified an in vitro model for DHL/THL DLBCLs and provide evidence for the therapeutic potential of BET inhibitor alone or in combination with BCL2 inhibitor. Electronic supplementary material The online version of this article (10.1186/s13045-019-0761-2) contains supplementary material, which is available to authorized users.