Contribution of Heparan Sulphate Binding in CCL21-Mediated Migration of Breast Cancer Cells

Abstract

Chemokine receptor CCR7 is implicated in the metastasis of breast cancer to the lymph nodes. Chemokine function is dependent upon their binding to both cell-surface heparan sulphate (HS) and to their specific receptors; thus, the role of HS in CCR7-mediated lymph node metastasis was investigated by creating a non-HS binding chemokine CCL21 (mut-CCL21). Mut-CCL21 (Δ103–134) induced leukocyte chemotaxis in diffusion gradients but did not stimulate trans-endothelial migration of PBMCs (p < 0.001) and 4T1-Luc cells (p < 0.01). Furthermore, the effect of heparin and HS on the chemotactic properties of wild-type (WT) and mut-CCL21 was examined. Interestingly, heparin and HS completely inhibit the chemotaxis mediated by WT-CCL21 at 250 and 500 µg/mL, whereas minimal effect was seen with mut-CCL21. This difference could potentially be attributed to reduced HS binding, as surface plasmon resonance spectroscopy showed that mut-CCL21 did not significantly bind HS compared to WT-CCL21. A murine model was used to assess the potential of mut-CCL21 to prevent lymph node metastasis in vivo. Mice were injected with 4T1-Luc cells in the mammary fat pad and treated daily for a week with 20 µg mut-CCL21. Mice were imaged weekly with IVIS and sacrificed on day 18. Luciferase expression was significantly reduced in lymph nodes from mice that had been treated with mut-CCL21 compared to the control (p = 0.0148), suggesting the potential to target chemokine binding to HS as a therapeutic option.

Heparin Specifically Interacts with Basic BBXB Motifs of the Chemokine CCL21 to Define CCR7 Signaling

“…Interestingly, heparin addition to chemokine-receptor binding and signaling assays indicates a ligand-specific formation of a complex with CCL21, but not with CCL19, that defines and limits CCR7 signaling in a ligand-dependent manner. Our results thus extend previous studies assessing the interaction of CCR7 ligands with different ECM proteins [ 33 , 41 , 42 ]. In addition, our study sheds light on the role of BBXB motifs and the charged C-terminus of CCL21 in receptor activation and ECM interaction.…”

Current Strategies of Photoacoustic Imaging Assisted Cancer Theragnostics toward Clinical Studies

“…The sentinel lymph node (SLN) is the first region to be invaded by breast cancer metastasis. Thus, the detection of SLNs plays a crucial role in the therapeutic management of breast cancer. , During surgery, it is not necessary to exenterate SLN while no obvious involvement in metastasis via accurate diagnosis. Nevertheless, differentiation of metastatic SLN from the normal or inflamed ones is still a serious challenge in clinical surgery.…”

“…Thus, the detection of SLNs plays a crucial role in the therapeutic management of breast cancer. 126,127 Uribe et al developed a dual-mode imaging system that integrated PA and US imaging to perform noninvasive detection of SLNs with the assistance of methylene blue dye, as shown in Figure 3b. 128 Their work may provide support in guiding percutaneous needle biopsies and axillary staging of breast cancer.…”

Emerging Roles of Chemokines in Cancer Immunotherapy

“…Chemokines are bi-functional in their ability to interact with their cognate receptors on target cells as well as proteoglycans, such as heparin sulfate (HS), present on cell surfaces and extracellular matrix. One article explored the possibility of using mutated CCL21, a CCR7-specific chemokine engineered to lack the HS-binding portion, to interfere with metastasis of tumor cells to the lymph nodes [ 1 ]. Similarly, a second article examined the possibility of using the HS-binding portion of CXCL9 to inhibit the angiogenic properties of diverse growth factors (VEGF, FGF, EGF) [ 2 ].…”

“…This antibody selectively binds to CCR4 on T-cell lymphomas and induces their elimination via antibody-mediated cellular cytotoxicity (ADCC) [ 9 ]. CXCR4 is one of the best-studied chemokine receptors associated with tumor growth and metastasis, as demonstrated in a separate review dedicated to CXCR4 in breast cancer [ 1 ]. This chemokine receptor is also the topic of a discussion focusing on targeting CXCR4 to improve tumor immunotherapy [ 10 ].…”