Background/Aim: KT2 is a lysine/tryptophan-rich peptide modified from Crocodylus siamensis Leucrocin I. In this study, we examined the cell toxicity, cellular uptake, anti-migration and anti-invasion activities of KT2 in A375.S2 human melanoma cells. Materials and Methods: A375.S2 cells were treated with KT2 peptide and then we performed MTT assay, study of cellular uptake by a confocal microscope, wound healing assay, transwell migration/invasion assay, and evaluation of the expression of metastasis-associated proteins. Results: KT2 can be internalized through the plasma membrane and can slightly alter cell morphology, decrease the percentage of viable cells and inhibit cell migration and invasion of A375.S2 cells in a dose-dependent manner. This peptide suppressed MMP-2 activity, as measured by gelatine zymography assay. The protein level of MMP-2 was decreased by KT2. KT2 also down-regulated metastasis pathway-related molecules, including FAK, RhoA, ROCK1, GRB2, SOS-1, p-JNK, p-c-Jun, PI3K, p-AKT (Thr308), p-AKT (Ser473), p-p38, MMP-9, NF-kB, and uPA. Conclusion: These results indicate that KT2 inhibits the migration and invasion of human melanoma cells by decreasing MMP-2 and MMP-9 expression through inhibition of FAK, uPA, MAPK, PI3K/AKT NF-kB, and RhoA–ROCK signalling pathways. These findings suggest that KT2 deserves further investigation as an anti-metastatic agent for human melanoma.

中文翻译：

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阳离子 KT2 肽（一种富含赖氨酸/色氨酸的肽）对人黑色素瘤 A375.S2 细胞的抗转移作用

背景/目的：KT2 是一种由暹罗鳄 Leucrocin I 修饰的富含赖氨酸/色氨酸的肽。在本研究中，我们检测了 KT2 在 A375.S2 人黑色素瘤细胞中的细胞毒性、细胞摄取、抗迁移和抗侵袭活性. 材料和方法：A375.S2 细胞用 KT2 肽处理，然后我们进行了 MTT 分析，通过共聚焦显微镜研究细胞摄取，伤口愈合分析，transwell 迁移/侵袭分析，以及转移相关蛋白表达的评估。结果：KT2可通过质膜内化，并能轻微改变细胞形态，降低活细胞百分比，并以剂量​​依赖性方式抑制A375.S2细胞的细胞迁移和侵袭。该肽抑制了 MMP-2 活性，如明胶酶谱分析所测得的。KT2降低了MMP-2的蛋白质水平。KT2 还下调转移通路相关分子，包括 FAK、RhoA、ROCK1、GRB2、SOS-1、p-JNK、pc-Jun、PI3K、p-AKT (Thr308)、p-AKT (Ser473)、p- p38、MMP-9、NF-kB 和 uPA。结论：这些结果表明 KT2 通过抑制 FAK、uPA、MAPK、PI3K/AKT NF-kB 和 RhoA-ROCK 信号通路来降低 MMP-2 和 MMP-9 的表达，从而抑制人黑色素瘤细胞的迁移和侵袭。这些发现表明 KT2 作为人类黑色素瘤的抗转移剂值得进一步研究。这些结果表明，KT2 通过抑制 FAK、uPA、MAPK、PI3K/AKT NF-kB 和 RhoA-ROCK 信号通路来降低 MMP-2 和 MMP-9 的表达，从而抑制人黑色素瘤细胞的迁移和侵袭。这些发现表明 KT2 作为人类黑色素瘤的抗转移剂值得进一步研究。这些结果表明，KT2 通过抑制 FAK、uPA、MAPK、PI3K/AKT NF-kB 和 RhoA-ROCK 信号通路来降低 MMP-2 和 MMP-9 的表达，从而抑制人黑色素瘤细胞的迁移和侵袭。这些发现表明 KT2 作为人类黑色素瘤的抗转移剂值得进一步研究。