Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemoon-gu, Seoul 02447, Korea.
Department of Science in Korean Medicine, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemoon-gu, Seoul 02447, Korea.
Int J Mol Sci. 2022 Mar 13;23(6):3094. doi: 10.3390/ijms23063094.
Melanoma is an immunogenic tumor and a serious type of skin cancer. Tumor-associated macrophages (TAMs) express an M2-like phenotype and are involved in all stages of melanomagenesis; it is hence a promising target for cancer immunotherapy. We herein investigated whether melittin-dKLA inhibits the growth of melanoma by inducing apoptosis of M2-like macrophages. For the in vitro study, a conditioned medium of macrophages was prepared from M0, M1, or M2-differentiated THP-1 cells with and without melittin-dKLA. The affinity of melittin for M2 macrophages was studied with FITC (fluorescein isothiocyanate)-conjugated melittin. For the in vivo study, murine melanoma cells were inoculated subcutaneously in the right flank of mice, melittin-dKLA was intraperitoneally injected at 200 nmol/kg every three days, and flow cytometry analysis of TAMs was performed. Since melittin binds preferentially to M2-like macrophages, melittin-dKLA induced more caspase 3 expression and cell death in M2 macrophages compared with M0 and M1 macrophages and melanoma cells. Melittin-dKLA significantly inhibited the proliferation and migration of M2 macrophages, resulting in a decrease in melanoma tumor growth in vivo. The CD206 M2-like TAMs were reduced, while the CD86 M1-like TAMs were not affected. Melittin-dKLA is therapeutically effective against melanoma by inducing the apoptosis of M2-like TAMs.
黑色素瘤是一种免疫原性肿瘤，也是一种严重的皮肤癌。肿瘤相关巨噬细胞（TAMs）表达 M2 样表型，并参与黑色素瘤发生的所有阶段；因此，它是癌症免疫治疗的一个有前途的靶点。我们在此研究了蜂毒素-dKLA 是否通过诱导 M2 样巨噬细胞凋亡来抑制黑色素瘤的生长。在体外研究中，用和不用蜂毒素-dKLA 从 M0、M1 或 M2 分化的 THP-1 细胞制备巨噬细胞条件培养基。用 FITC（异硫氰酸荧光素）缀合的蜂毒素研究蜂毒素与 M2 巨噬细胞的亲和力。在体内研究中，将鼠黑色素瘤细胞皮下接种于小鼠右侧肋部，每三天腹腔内注射 200nmol/kg 的蜂毒素-dKLA，并进行 TAMs 的流式细胞术分析。由于蜂毒素优先与 M2 样巨噬细胞结合，与 M0 和 M1 巨噬细胞和黑色素瘤细胞相比，蜂毒素-dKLA 诱导 M2 巨噬细胞中更多的 caspase 3 表达和细胞死亡。蜂毒素-dKLA 显著抑制 M2 巨噬细胞的增殖和迁移，导致体内黑色素瘤肿瘤生长减少。CD206 M2 样 TAMs 减少，而 CD86 M1 样 TAMs 不受影响。蜂毒素-dKLA 通过诱导 M2 样 TAMs 凋亡对黑色素瘤具有治疗效果。
