Dataset Information

CXCL9 induces chemotaxis, chemorepulsion and endothelial barrier disruption through CXCR3-mediated activation of melanoma cells.

ABSTRACT:

Background

Metastasis is associated with poor prognosis for melanoma. The formation of metastases is a multi-step process, in which cancer cells can subsequently acquire the potential to intravasate into the blood or lymph vessels, disseminate through the circulation, extravasate through the endothelium and invade the connective tissue. There is increasing evidence that chemokines have a pivotal role in the dissemination and establishment of melanoma metastasis.

Methods

We isolated melanoma cells from melanoma metastasis and performed different migration assays and transendothelial resistance measurements of endothelial monolayers co-cultured with melanoma cells, in order to monitor barrier function and diapedesis and confirmed these results by confocal microscopy.

Results

We observed that tumour endothelial cells (ECs) secrete high levels of CXCL9 in all, and CXCL10 in most melanoma metastases. Migration studies revealed that low concentrations of these chemokines induce chemotaxis, whereas high concentrations induce spontaneous migration of melanoma cells (chemokinesis/chemorepulsion) and the disruption of the endothelial barrier, resulting in an accelerated transendothelial migration (TEM). Addition of anti-CXCL9 or anti-CXCR3 antibodies to the co-cultures delayed the TEM of melanoma cells.

Conclusion

Our data represent novel mechanisms by which tumour cells in melanoma metastases might use the chemokine-expressing endothelium to leave the tumour and eventually to form additional metastases at distinct sites.

SUBMITTER: Amatschek S

PROVIDER: S-EPMC3049560 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BACKGROUND:Mesenchymal stem cells (MSCs) are known to home to injured and inflamed regions via the bloodstream to assist in tissue regeneration in response to signals of cellular damage. However, the factors and mechanisms that affect their transendothelial migration are still unclear. In this study, the mechanisms involved in interleukin-1? (IL-1?) enhancing the transendothelial migration of MSCs were investigated. METHODS:Immunofluorescence staining and Western blotting were used to observe IL-1?-induced CXC chemokine receptor 3 (CXCR3) expression on MSCs. Quantitative real-time PCR and ELISA were used to demonstrate IL-1? upregulated both chemokine (C-X-C motif) ligand 9 (CXCL9) mRNA and CXCL9 ligand secretion in human umbilical vein endothelial cells (HUVECs). Monolayer co-cultivation, agarose drop chemotaxis, and transwell assay were conducted to investigate the chemotaxis invasion and transendothelial migration ability of IL-1?-induced MSCs in response to CXCL9. RESULTS:In this study, our immunofluorescence staining showed that IL-1? induces CXCR3 expression on MSCs. This result was confirmed by Western blotting. Following pretreatment with protein synthesis inhibitor cycloheximide, we found that IL-1? induced CXCR3 on the surface of MSCs via protein synthesis pathway. Quantitative real-time PCR and ELISA validated that IL-1? upregulated both CXCL9 mRNA and CXCL9 ligand secretion in HUVECs. In response to CXCL9, chemotaxis invasion and transendothelial migration ability were increased in IL-1?-stimulated MSCs. In addition, we pretreated MSCs with CXCR3 antagonist AMG-487 and p38 MAPK inhibitor SB203580 to confirm CXCR3-CXCL9 interaction and the role of CXCR3 in IL-1?-induced chemotaxis invasion and transendothelial migration. CONCLUSION:We found that IL-1? induces the expression of CXCR3 through p38 MAPK signaling and that IL-1? also enhances CXCL9 ligand secretion in HUVECs. These results indicated that IL-1? promotes the transendothelial migration of MSCs through CXCR3-CXCL9 axis. The implication of the finding could enhance the efficacy of MSCs homing to target sites.