背景:服用BRAF抑制剂如维罗非尼(PLX4032)治疗黑色素瘤的患者中有20%至30%会发生皮肤鳞状细胞癌。
目的:本研究旨在阐明水薄荷精油的化学预防作用。石灰(EO)及其主要成分,柠檬烯和香芹酮(L+C)占环氧乙烷的45.68%,针对PLX4032诱导的皮肤副作用。
方法:PLX4032在7,12-二甲基苯并[a]蒽(DMBA)/12-O-十四烷酰基佛波醇-13-乙酸酯(TPA)诱导的两阶段皮肤癌发生小鼠模型中加速皮肤乳头状瘤形成和角质形成细胞HRAS突变使用EO和L+C的体内生物功效评估。西方印迹,免疫化学,和角质形成细胞-巨噬细胞共培养试验。
结果:用EO处理抑制了集落形成能力,细胞迁移,入侵,并诱导PDVHRASQ61L角质形成细胞的G2/M细胞周期阻滞和凋亡,和L+C处理抑制集落形成,PDV细胞的细胞迁移和侵袭。在用DMBA/TPA(DT组)或DMBA/TPA与PLX4032(DTP组)刺激的小鼠皮肤中,与DT或DTP对照组相比,局部应用EO和L+C可显著延迟乳头状瘤的出现并降低乳头状瘤的发生率.组织病理学结果显示EO和L+C处理减弱了K14+角质形成细胞增殖和矛盾的MAPK激活,并将小鼠皮肤微环境中的巨噬细胞从M2(CD163)转移到M1(iNOS)。EO或L+C预处理的PDV角质形成细胞的条件培养基促进M0巨噬细胞从THP-1细胞分化成M1样巨噬细胞。
结论:这项研究表明,EO和L+C联合使用可通过重编程巨噬细胞群和抑制角质形成细胞活性来预防PLX4032诱导的小鼠皮肤副作用和皮肤癌变。薄荷EO和天然产物L+C均可被认为是有效的化学预防剂,其可用于减少施用BRAF抑制剂的人类患者的皮肤损伤。
BACKGROUND: Twenty to thirty percent of patients taking BRAF inhibitors such as vemurafenib (PLX4032) for melanoma develop cutaneous squamous cell carcinomas.
OBJECTIVE: This study aimed to elucidate the chemopreventive effect of essential oil from Mentha aquatica L. cv. Lime (EO) and its major constituents, limonene and carvone (L + C) that made up 45.68% of the EO, against PLX4032-induced cutaneous side effects.
METHODS: PLX4032 accelerated skin papilloma formation and keratinocyte HRAS mutation in 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced two-stage skin carcinogenesis mouse model was used to evaluate the in vivo bioefficacy of EO and L + C. The effects and molecular mechanisms of EO and L + C on deregulating mouse PDVHRASQ61L keratinocyte activities were demonstrated using a spectrum of bioactivity assays, western blotting, immunochemistry, and keratinocyte-macrophage co-culture assay.
RESULTS: Treatment with EO suppressed colony formation ability, cell migration, invasion, and induced G2/M cell-cycle arrest and apoptosis in PDVHRASQ61L keratinocytes, and L + C treatment inhibited colony formation, cell migration and invasion of PDV cells. In mouse skin irritated with DMBA/TPA (DT group) or DMBA/TPA with PLX4032 (DTP group), topical application of EO and L + C significantly delayed papilloma appearance and reduced papilloma incidence compared to DT or DTP controls. Histopathology results showed that EO and L + C treatment attenuated K14+ keratinocyte proliferation and paradoxical MAPK activation, and shifted the macrophage population from M2 (CD163+) to M1 (iNOS+) in the mouse skin microenvironment. The conditioned medium of EO or L + C pre-treated PDV keratinocytes promoted M0 macrophages to differentiate from THP-1 cells into M1-like macrophages.
CONCLUSIONS: This study demonstrates that EO and L + C in combination prevent PLX4032-induced cutaneous side-effects and skin carcinogenesis in mice through reprogramming the macrophage cell population and inhibiting keratinocyte activity. Both mint EO and the natural products L + C can be considered to be effective chemopreventive agents that might be useful in reducing cutaneous lesions in human patients administrated with BRAF inhibitors.