Rabbit Anti-Human CCL21 monoclonal antibody, clone 7I5M29

Ets-1 is a prototype of the ETS protein family. Members of the ETS protein family contain a unique ETS domain. Ets-1 is associated with cancer progression and metastasis in many types of cancer. Many studies have shown a link between elevated expression of Ets-1 in cancer biopsies and poor survival. CCR7 is a chemokine that binds to specific ligand CCL21/CCL19. CCR7 expression is associated with tumor metastasis and infiltration into lymph nodes. The objective of this study was to test whether Ets-1 could regulate CCR7 expression and enhance tumor metastasis. Our data showed that CCR7 expression was downregulated in Ets-1-deficient T cells upon T-cell stimulation. Overexpression of Ets-1 increased CCR7 expression in breast cancer cell lines. In contrast, knockdown of Ets-1 reduced CCR7 expression. Ets-1 could directly bind to CCR7 promoter and mediate CCR7 expression in luciferase reporter assays and chromatin immunoprecipitation assays. Transactivation activity of Ets-1 was independent of the Pointed domain of Ets-1. Ets-1 could also enhance NF-kappa B and CBP transactivation of CCR7 promoter. Our results also showed that Ets-1 could modulate cancer cell transmigration by altering CCR7 expression in transwell assay and wound healing assay. Taken together, our data suggest that Ets-1 can enhance CCR7 expression and contribute to tumor cell migration.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is frequently accompanied by excruciating pain, which has been associated with attraction of cancer cells and their invasion of intrapancreatic sensory nerves. Neutralization of the chemokine CCL2 reduced cancer-associated pain in a clinical trial, but there have been no systematic analyses of the highly diverse chemokine families and their receptors in PDAC. METHODS: We performed an open, unbiased RNA -interference screen of mammalian chemokines in co-cultures of mouse PDAC cells (K8484) and mouse peripheral sensory neurons, and confirmed findings in studies of DT8082 PDAC cells. We studied the effects of chemokines on migration of PDAC cell lines. Orthotopic tumors were grown from K8484 cells in mice, and mice were given injections of neutralizing antibodies against chemokines, antagonists, or control anti-bodies. We analyzed abdominal mechanical hypersensitivity and collected tumors and analyzed them by histology and immunohistochemistry to assess neural remodeling. We collected PDAC samples and information on pain levels from 74 patients undergoing resection and measured levels of CXCR3 and CCR7 by immunohistochemistry and immuno-blotting. RESULTS: Knockdown of 9 chemokines in DRG neurons significantly reduced migration of PDAC cells to-wards sensory neurons. Sensory neuron-derived CCL21 and CXCL10 promoted migration of PDAC cells via their receptors CCR7 and CXCR3, respectively, which were expressed by cells in orthotopic tumors and PDAC specimens from patients. Neutralization of CCL21 or CXCL10, or their receptors, in mice with orthotopic tumors significantly reduced nociceptive hypersensitivity and nerve fiber hypertrophy and improved behavioral parameters without affecting tumor infiltration by T cells or neutrophils. Increased levels of CXCR3 and CCR7 in human PDAC specimens were associated with increased fre-quency of cancer-associated pain, determined from patient questionnaires. CONCLUSIONS: In an unbiased screen of che-mokines, we identified CCL21 and CXCL10 as proteins that promote migration of pancreatic cancer cells toward sensory neurons. Inhibition of these chemokines or their receptors reduce hypersensitivity in mice with orthotopic tumors, and patients with PDACs with high levels of the chemokine re-ceptors of CXCR3 and CCR7 had increased frequency of cancer -associated pain.