Abstract 2037: Macrophage Inflammatory Protein-3 beta (MIP-3β) from cancer-associated fibroblasts promote the proliferation of melanoma cells

Abstract

Abstract Introduction: Malignant tumors are composed of cancer cells and various types of stromal cells, including fibroblasts, vascular endothelial cells, and immune cells. It has been reported that fibroblasts in the tumor stroma termed as cancer-associated fibroblasts (CAFs) may affect cancer progression. However, the currently available evidence regarding the function of CAFs remains controversial, with some studies reporting stimulatory activity and some studies reporting inhibitory activity in malignant melanoma cells. Previously, we reported that CAFs possibly exert a stimulatory effect on the proliferation of melanoma cells. In this study, we identified a factor from CAFs that are involved in melanoma progression. Materials and Methods: We used three malignant melanoma cell lines, namely MMAc, COLO679, and A375. Three CAFs and one type of non-affected fibroblasts (NAFs) were established from sebaceous carcinoma/skin malignant melanoma and normal skin, respectively. Serum-free conditioned medium from CAFs (CAF-CM) was prepared as follows: CAFs were seeded into 100-mm plastic dishes with 10 ml of Dulbecco's modification of Eagle medium (DMEM) containing 5% fetal calf serum. To obtain CAF-CM, CAFs were washed using phosphate-buffered saline and subsequently incubated for 3 days with serum-free DMEM, and the conditioned medium was collected as CAF-CM. Additionally, we obtained NAF-CM from NAFs using the same procedure. These fibroblasts were cultured and used before the 15th passage. The cytokines included in each conditioned medium were determined using cytokine assay. Subsequently, we selected some cytokines, which were released more abundantly in CAFs than in NAFs, as potential factors affecting the proliferation of melanoma cells. The effects of these cytokines on the proliferation of melanoma cells were determined using MTT assay and cytometry assay using a Coulter Counter. Results: CAF-CM contained significantly high concentration of MIP-3β, in compared with that in NAF-CM. In addition, MIP-3β significantly increases in the proliferation of melanoma cells, A375 and COLO679, at 48 h and 72 h culture. Conclusion: CAFs from skin cancer might promote the proliferation of malignant melanoma cells via MIP-3β signaling. Citation Format: Heishiro Fujikawa, Masakazu Yashiro, Takaharu Hatano, Shusaku Maeda, Hisashi Motomura. Macrophage Inflammatory Protein-3 beta (MIP-3β) from cancer-associated fibroblasts promote the proliferation of melanoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2037.