Abstract 3763: Effect of cancer-associated fibroblasts on lymphatic vessel formation in malignant melanoma

Abstract

Abstract Introduction: It has been reported that cancer-associated fibroblasts (CAFs) in tumor microenvironment may play an important role for the progression and metastasis of cancer cells. Some reports suggested that CAFs may promote tumor lymphangiogenesis. In malignant melanoma, lymph node metastasis is one of important prognostic factors. Tumor lymphangiogenesis may be controlled not only by tumor cells but also tumor microenvironment such as CAFs, however no study about the interaction between CAFs and human lymphatic endothelial cells (HLECs) was found. Then, we evaluated the effect of CAFs on lymphatic vessel formation in malignant melanoma. Materials and methods: We used CAFs, normal tissue associated fibroblasts (NAFs) established from a patient of malignant melanoma, and HLECs. Serum-free conditioned medium was obtained from NAFs (NAF-CM) or CAFs (CAFs-CM). CAFs and NAFs were cultured with or without supernatant from malignant melanoma cells. HLECs were cultured by EBM with 50% of NAF-CM or CAFs-CM. Control group was cultured with 50% EBM and 50% of serum-free medium. The effect of each CM on the proliferation of HLECs was examined by CCK assay and tube formation assay. Tube formation was assessed at 12 hours of incubation by fluorescence microscope. Result: CAFs-CM significantly decreased the proliferation of HLECs in comparison with NAFs-CM after 48, 72 and 96 hours of incubation by CCK assay. In tube formation assay, tube length and number of tubes and junctions were also significantly shorter and smaller in CAFs group, in compared with the control and NAFs group. Conclusion: CAFs might have a suppressive effect on HLECs, resulting in inhibition of lymphangiogenesis. Citation Format: Shusaku Maeda, Masakazu Yashiro, Hisashi Motomura, Takaharu Hatano, Heishiro Fujikawa. Effect of cancer-associated fibroblasts on lymphatic vessel formation in malignant melanoma [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 3763.