Abstract 5115: Cancer-associated fibroblasts under the influence of melanoma cells might stimulate the lymphatic vessel formation

Abstract

Abstract Introduction: Cancer-associated fibroblasts (CAFs) in tumor microenvironment have an interaction with tumor cells and play an important role for the progression and metastasis. Tumor lymphangiogenesis may be controlled by not only tumor cells but also tumor microenvironment, and some reports suggested that CAFs may promote tumor lymphangiogenesis. In malignant melanoma, lymph node metastasis is important prognostic factor. However, no study about the interaction among CAFs, tumor cells, and human lymphatic endothelial cells (HLECs) was found. In this study, we evaluated the effect of CAFs on lymphatic vessel formation in malignant melanoma. Materials and methods: We used CAFs established from a primary malignant melanoma, HLECs, and two melanoma cell lines (MMAc, COLO679). CAFs and melanoma cell lines were cultured with DMEM. Serum-free conditioned medium (CM) was obtained from CAFs (CAF-CM) and two melanoma cells (MMAc-CM, COLO679-CM). Also, CM from CAFs cultured with MMAc-CM (MMAcCAF-CM) and COLO679-CM (COLO679CAF-CM) was obtained. HLECs were cultured by endothelial growth medium (EGM) in combination with 50% of each CM. Control group was cultured with 50% EGM and 50% of serum-free endothelial basal medium. The effect of each CM on the proliferation of HLECs was examined by CCK assay and tube formation assay. Tube formation was assessed by counting total tube length, number of tubes and junctions at 12 hours of incubation. Result: Both MMAcCAF-CM and COLO679CAF-CM significantly increased the proliferation of HLECs in compared with the control or CAF-CM alone, after 24, 48 and 72 hours of incubation. In tube formation assay, both tube length and number of tubes formed by HLECs were significantly longer and larger in MMAcCAF-CM and MMAc-CM group than control group. The tube length, number of tubes and junctions treated by MMAcCAF-CM or COLO679CAF-CM were longer and larger than in control and CAF-CM group. Conclusion: CAFs under the influence of melanoma cells might have a more progressive effect on HLECs, resulting in promotion of lymphangiogenesis. Citation Format: Shusaku Maeda, Masakazu Yashiro, Hisashi Motomura, Takaharu Hatano, Heishiro Fujikawa. Cancer-associated fibroblasts under the influence of melanoma cells might stimulate the lymphatic vessel formation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5115.