As these variants have an identical genetic background,

any molecular differences between these variants reflect alterations associated with the ability to form brain metastasis. We are currently using these variants to establish a melanoma brain metastasis specific genetic signature. Gelatin zymography was used to determine MMP-2 activity in the melanoma variants. Brain metastatic variants displayed a relatively higher activity level of MMP-2 than local variants, indicating a greater ability of the metastatic variants to invade through basement membrane. To identify chemokine receptors that might be involved in melanoma homing to the brain, we analyzed the expression of chemokine receptors and the membrane-bound

Lumacaftor cell line chemokine CX3CL1 in the local and metastatic variants. Five chemokine receptors (CCR3, CCR4, CXCR3, CXCR7 and CX3CR1) and CX3CL1 were expressed on the melanoma variants. Other surface molecules associated Decitabine clinical trial with tumor progression were found to be differentially expressed on local and metastatic variants. Utilizing microarrays, we generated gene expression profiles of the melanoma variants. This analysis revealed a set of genes differentially expressed in local and metastatic variants. Ongoing work focuses on differential interactions of local and brain metastasizing variants with brain endothelia. This study was supported by the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation (Needham, MA, USA) O118 Characterization of Interleukin-8 Promoted PAK6 Protease Expression and Activity in Relation to Prostate Cancer Metastasis to the Bone Ashleigh Hill 1 , Johanna Pettigrew1, Pamela Maxwell1, David Waugh1 1 Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland, UK Interleukin-8 (IL-8) is a proinflammatory CXC chemokine which activates intracellular signalling downstream of two cell surface receptors CXCR1 and CXCR2.

We have demonstrated increased expression of IL-8, CXCR1 and CXCR2 in malignant epithelium in human prostate cancer, with expression greatest in androgen-independent metastatic prostate cancer tissue. However, since CXCR1 and CXCR2 receptors are also expressed on endothelial cells, infiltrating neutrophils and tumour associated macrophages, the release of IL-8 from cancer cells is likely to make a significant contribution in regulating the constitution and activity of the tumour microenvironment. In addition, the detection of CXCR1 and CXCR2 expression on bone marrow stromal cells indicates that infiltrating metastatic cells with elevated IL-8 expression may have enhanced capacity to regulate the microenvironment of the bone marrow cavity.