Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
Auckland Regional Cancer and Blood Service, Auckland City Hospital, Private Bag 92024, Auckland, 1142, New Zealand.
Cancer Chemother Pharmacol. 2019 Oct;84(4):739-748. doi: 10.1007/s00280-019-03904-4. Epub 2019 Jul 19.
Fluorouracil (5-FU), a chemotherapeutic agent widely used in the treatment of numerous common malignancies, causes oral mucositis in a proportion of patients. The contribution of drug transport processes to the development of this toxicity is currently unknown. This work aimed to establish and optimise a simple phenotyping assay for 5-FU uptake into primary buccal mucosal cells (BMC).
The uptake kinetics of radiolabelled 5-FU were determined in pooled BMC freshly collected from healthy volunteers. The inter- and intra-individual variability in 5-FU uptake was then assessed across a cohort that included both healthy volunteers and cancer patients.
5-FU uptake into pooled primary BMC was both time and concentration dependent. An Eadie-Hofstee analysis suggested two components; a high-affinity (K = 3.3 µM) low-capacity ([Formula: see text] = 57.8 pmol min 10 viable cells) transporter, and a high-capacity ([Formula: see text] = 1230 pmol min 10 viable cells) low-affinity (K = 3932 µM) transporter. There was 180-fold variation in the rate of 5-FU uptake into BMC (0.10-17.86 pmol min 10 viable cells) across the 34 subjects (healthy participants N = 24, cancer patients N = 10). Notably, retesting of a subset of these participants (N = 16) multiple times over a period of up to 140 days demonstrated poor stability of the uptake phenotype within individuals.
The uptake of 5-FU into healthy oral mucosal cells is a highly variable process facilitated by membrane transporters at pharmacologically relevant concentrations. This bioassay is simple, minimally invasive, and suitable for phenotypic analysis of drug transport in healthy primary cells.
氟尿嘧啶（5-FU）是一种广泛用于治疗多种常见恶性肿瘤的化疗药物，会导致一部分患者出现口腔黏膜炎。目前尚不清楚药物转运过程对这种毒性的发展有何贡献。本研究旨在建立并优化一种简单的口腔颊黏膜细胞（BMC）摄取放射性标记的 5-FU 的表型分析方法。
从健康志愿者中采集新鲜的 BMC 细胞，测定放射性标记的 5-FU 的摄取动力学。然后，在包括健康志愿者和癌症患者的队列中评估 5-FU 摄取的个体内和个体间变异性。
5-FU 进入汇集的初级 BMC 细胞的摄取既依赖于时间又依赖于浓度。Eadie-Hofstee 分析表明存在两种成分；一种是高亲和力（K=3.3 μM）低容量（[公式：见正文] = 57.8 pmol min 10 个活细胞）转运体，另一种是高容量（[公式：见正文] = 1230 pmol min 10 个活细胞）低亲和力（K=3932 μM）转运体。在 34 名受试者（健康参与者 N=24，癌症患者 N=10）中，BMC 摄取 5-FU 的速度差异达 180 倍（0.10-17.86 pmol min 10 个活细胞）。值得注意的是，对其中一组参与者（N=16）进行多次重复测试，时间长达 140 天以上，结果显示个体内摄取表型的稳定性较差。
在药理学相关浓度下，健康口腔黏膜细胞摄取 5-FU 是一个高度可变的过程，由膜转运体介导。这种生物测定方法简单、微创，适用于健康原代细胞中药物转运的表型分析。
