Abstract:BackgroundThe expression of the chemokine receptor CCR6 has been previously correlated with higher grades and stages of breast cancer and decreased relapse-free survival. Also, its cognate chemokine ligand CCL20 has been reported to induce proliferation of cultured human breast epithelial cells.MethodsTo establish if CCR6 plays a functional role in mammary tumorigenesis, a bigenic MMTV-PyMT CCR6-null mouse was generated and mammary tumor development was assessed. Levels of tumor-infiltrating immune cells withi… Show more
“…+ T EM (31,32), Th-17 cells (33), B cells, immature dendritic cells (DCs) (34), and tumor-promoting macrophages (35). We also observed high CD200 expression levels in the TME (Fig.…”
Section: Tme Shapes the Immune Landscape And Determines The Immune Sumentioning
The recent development of immunotherapy as a cancer treatment has proved effective over recent years, but the precise dynamics between the tumor microenvironment (TME), nontumor microenvironment (NTME), and the systemic immune system remain elusive. Here, we interrogated these compartments in hepatocellular carcinoma (HCC) using high-dimensional proteomic and transcriptomic analyses. By time-of-flight mass cytometry, we found that the TME was enriched in regulatory T cells (Tregs), tissue resident memory CD8 + T cells (T RM s), resident natural killer cells (NK R s), and tumorassociated macrophages (TAMs). This finding was also validated with immunofluorescence staining on Foxp3Interestingly, Tregs and T RM s isolated from the TME expressed multiple markers for T-cell exhaustion, including PD-1, Lag-3, and Tim-3 compared with Tregs and T RM s isolated from the NTME. We found PD-1 + T RM s were the predominant T-cell subset responsive to anti-PD-1 treatment and significantly reduced in number with increasing HCC tumor progression. Furthermore, T-bet was identified as a key transcription factor, negatively correlated with PD-1 expression on memory CD8 + T cells, and the PD-1:T-bet ratio increased upon exposure to tumor antigens. Finally, transcriptomic analysis of tumor and adjacent nontumor tissues identified a chemotactic gradient for recruitment of TAMs and NK R s via CXCR3/ CXCL10 and CCR6/CCL20 pathways, respectively. Taken together, these data confirm the existence of an immunosuppressive gradient across the TME, NTME, and peripheral blood in primary HCC that manipulates the activation status of tumor-infiltrating leukocytes and renders them immunocompromised against tumor cells. By understanding the immunologic composition of this gradient, more effective immunotherapeutics for HCC may be designed.CyTOF | tumor microenvironment | regulatory T cells | resident memory T cells | hepatocellular carcinoma
“…+ T EM (31,32), Th-17 cells (33), B cells, immature dendritic cells (DCs) (34), and tumor-promoting macrophages (35). We also observed high CD200 expression levels in the TME (Fig.…”
Section: Tme Shapes the Immune Landscape And Determines The Immune Sumentioning
The recent development of immunotherapy as a cancer treatment has proved effective over recent years, but the precise dynamics between the tumor microenvironment (TME), nontumor microenvironment (NTME), and the systemic immune system remain elusive. Here, we interrogated these compartments in hepatocellular carcinoma (HCC) using high-dimensional proteomic and transcriptomic analyses. By time-of-flight mass cytometry, we found that the TME was enriched in regulatory T cells (Tregs), tissue resident memory CD8 + T cells (T RM s), resident natural killer cells (NK R s), and tumorassociated macrophages (TAMs). This finding was also validated with immunofluorescence staining on Foxp3Interestingly, Tregs and T RM s isolated from the TME expressed multiple markers for T-cell exhaustion, including PD-1, Lag-3, and Tim-3 compared with Tregs and T RM s isolated from the NTME. We found PD-1 + T RM s were the predominant T-cell subset responsive to anti-PD-1 treatment and significantly reduced in number with increasing HCC tumor progression. Furthermore, T-bet was identified as a key transcription factor, negatively correlated with PD-1 expression on memory CD8 + T cells, and the PD-1:T-bet ratio increased upon exposure to tumor antigens. Finally, transcriptomic analysis of tumor and adjacent nontumor tissues identified a chemotactic gradient for recruitment of TAMs and NK R s via CXCR3/ CXCL10 and CCR6/CCL20 pathways, respectively. Taken together, these data confirm the existence of an immunosuppressive gradient across the TME, NTME, and peripheral blood in primary HCC that manipulates the activation status of tumor-infiltrating leukocytes and renders them immunocompromised against tumor cells. By understanding the immunologic composition of this gradient, more effective immunotherapeutics for HCC may be designed.CyTOF | tumor microenvironment | regulatory T cells | resident memory T cells | hepatocellular carcinoma
“…The expression of stemness-associated inflammatory cytokines namely; IL-6 and IL-8, and gp130 mRNAs were downregulated by 39%, 38% and 34% in Syndecan-1-silenced SUM149 and by 55%, 61% and 49% in SKBR3 upon Syndecan-1 knockdown, respectively. A relevant clue for regulation of IL-6 is the chemokine CCL20, which induces proliferation of cultured human breast epithelial cells [47] and is involved in IL-6 induction [48]. CCL20 mRNA was downregulated by 40% and 51% in Syndecan-1 knockdown SUM-149 and SKBR3 compared to control cells, respectively, suggesting the existence of a Syndecan-1/CCL20/IL-6 axis.Fig.…”
BackgroundInflammatory breast cancer (IBC), a particularly aggressive form of breast cancer, is characterized by cancer stem cell (CSC) phenotype. Due to a lack of targeted therapies, the identification of molecular markers of IBC is of major importance. The heparan sulfate proteoglycan Syndecan-1 acts as a coreceptor for growth factors and chemokines, modulating inflammation, tumor progression, and cancer stemness, thus it may emerge as a molecular marker for IBC.MethodsWe characterized expression of Syndecan-1 and the CSC marker CD44, Notch-1 & -3 and EGFR in carcinoma tissues of triple negative IBC (n = 13) and non-IBC (n = 17) patients using qPCR and immunohistochemistry. Impact of siRNA-mediated Syndecan-1 knockdown on the CSC phenotype of the human triple negative IBC cell line SUM-149 and HER-2-overexpressing non-IBC SKBR3 cells employing qPCR, flow cytometry, Western blotting, secretome profiling and Notch pharmacological inhibition experiments. Data were statistically analyzed using Student’s t-test/Mann-Whitney U-test or one-way ANOVA followed by Tukey’s multiple comparison tests.ResultsOur data indicate upregulation and a significant positive correlation of Syndecan-1 with CD44 protein, and Notch-1 & -3 and EGFR mRNA in IBC vs non-IBC. ALDH1 activity and the CD44(+)CD24(-/low) subset as readout of a CSC phenotype were reduced upon Syndecan-1 knockdown. Functionally, Syndecan-1 silencing significantly reduced 3D spheroid and colony formation. Intriguingly, qPCR results indicate downregulation of the IL-6, IL-8, CCL20, gp130 and EGFR mRNA upon Syndecan-1 suppression in both cell lines. Moreover, Syndecan-1 silencing significantly downregulated Notch-1, -3, -4 and Hey-1 in SUM-149 cells, and downregulated only Notch-3 and Gli-1 mRNA in SKBR3 cells. Secretome profiling unveiled reduced IL-6, IL-8, GRO-alpha and GRO a/b/g cytokines in conditioned media of Syndecan-1 knockdown SUM-149 cells compared to controls. The constitutively activated STAT3 and NFκB, and expression of gp130, Notch-1 & -2, and EGFR proteins were suppressed upon Syndecan-1 ablation. Mechanistically, gamma-secretase inhibition experiments suggested that Syndecan-1 may regulate the expression of IL-6, IL-8, gp130, Hey-1, EGFR and p-Akt via Notch signaling.ConclusionsSyndecan-1 acts as a novel tissue biomarker and a modulator of CSC phenotype of triple negative IBC via the IL-6/STAT3, Notch and EGFR signaling pathways, thus emerging as a promising therapeutic target for IBC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-017-0621-z) contains supplementary material, which is available to authorized users.
“…In a model of breast cancer development related to expression of a polyoma virus gene, tumor macrophages were found to be decreased in tumors that developed in CCR6-deficient mice. 28 Two independent studies utilizing different murine models of atherosclerosis found that atheromas developing in CCR6-deficient mice had decreased infiltrating macrophages. 29,30 Murine monocyte migration to CCL20 in vitro was shown in one of these studies.…”
Interactions between the inflammatory chemokine CCL20 and its receptor CCR6 have been implicated in promoting colon cancer; however, the mechanisms behind this effect are poorly understood. We have previously demonstrated that deficiency of CCR6 is associated with decreased tumor macrophage accumulation in a model of sporadic intestinal tumorigenesis. In this study, we aimed to determine the role of stromal CCR6 expression in a murine syngeneic transplantable colon cancer model. We show that deficiency of host CCR6 is associated with decreased growth of syngeneic CCR6-expressing colon cancers. Colon cancers adoptively transplanted into CCR6-deficient mice have decreased tumor-associated macrophages without alterations in the number of monocytes in blood or bone marrow. CCL20, the unique ligand for CCR6, promotes migration of monocytes in vitro and promotes accumulation of macrophages in vivo. Depletion of tumor-associated macrophages decreases the growth of tumors in the transplantable tumor model. Macrophages infiltrating the colon cancers in this model secrete the inflammatory mediators CCL2, IL-1a, IL-6 and TNFa. Ccl2, Il1a and Il6 are consequently downregulated in tumors from CCR6-deficient mice. CCL2, IL-1a and IL-6 also promote proliferation of colon cancer cells, linking the decreased macrophage migration into tumors mediated by CCL20-CCR6 interactions to the delay in tumor growth in CCR6-deficient hosts. The relevance of these findings in human colon cancer is demonstrated through correlation of CCR6 expression with that of the macrophage marker CD163 as well as that of CCL2, IL1a and TNFa. Our findings support the exploration of targeting the CCL20-CCR6 pathway for the treatment of colon cancer.
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