Liminga G, Nygren P, Dhar S, Nilsson K, Larsson R
Division of Clinical Pharmacology, University Hospital, Uppsala University, Sweden.
Anticancer Drugs. 1995 Aug;6(4):578-85. doi: 10.1097/00001813-199508000-00011.
Calcein acetoxymethyl ester (calcein/AM) and some related cellular dyes with a cytoplasmic distribution were investigated with respect to cellular hydrolysis, accumulation, efflux and cytotoxicity in a panel of established human cell lines, including multidrug resistant (MDR) phenotypes. At 0.1-1 micrograms/ml, calcein/AM was highly cytotoxic against several cell lines, even after short-term exposure (30 min). Calcein/AM induced no immediate loss (3 h) of membrane integrity and the drug was more active against low compared with high density plated cells. In cell lines with the MDR phenotype and in the renal carcinoma cell line ACHN, the drug was considerably less active. Non-esterified calcein had no effect and calcein/AM was significantly more potent than other structurally related fluorescein analogs and AM esters tested. Although MDR cell lines showed a decreased cellular hydrolysis and accumulation of the dye, there was no strict relationship between cytoplasmic calcein exposure and cytotoxic activity. The rate of efflux was low in the two most sensitive cell lines, the human lymphoma U-937-GTB and its vincristine (vcr) resistant subline U-937/vcr10, while the remaining cell lines showed similar biphasic efflux patterns, including cell lines of the MDR phenotype. The results show that calcein/AM has cytotoxic activity against human tumor cell lines at low concentrations. The effect appears dependent on the intracellular trapping of the drug, although the specific cellular target remains unknown. Due to its cytotoxic efficacy and unique principle of cellular drug delivery, further investigation of calcein/AM and related compounds as potentially new anticancer agents seems warranted.
在一组已建立的人类细胞系中，包括多药耐药（MDR）表型，研究了钙黄绿素乙酰氧基甲酯（钙黄绿素/AM）和一些具有细胞质分布的相关细胞染料在细胞水解、积累、外排和细胞毒性方面的情况。在0.1 - 1微克/毫升的浓度下，即使经过短期暴露（30分钟），钙黄绿素/AM对几种细胞系也具有高度细胞毒性。钙黄绿素/AM不会立即导致膜完整性丧失（3小时），并且该药物对低密度接种的细胞比对高密度接种的细胞更具活性。在具有MDR表型的细胞系和肾癌细胞系ACHN中，该药物的活性明显较低。非酯化的钙黄绿素没有作用，并且钙黄绿素/AM比其他测试的结构相关的荧光素类似物和AM酯的效力明显更强。尽管MDR细胞系显示出染料的细胞水解和积累减少，但细胞质中钙黄绿素的暴露与细胞毒性活性之间没有严格的关系。在两个最敏感的细胞系，即人淋巴瘤U - 937 - GTB及其长春新碱（vcr）耐药亚系U - 937/vcr10中，外排速率较低，而其余细胞系显示出相似的双相外排模式，包括MDR表型的细胞系。结果表明，钙黄绿素/AM在低浓度下对人类肿瘤细胞系具有细胞毒性活性。尽管具体的细胞靶点仍然未知，但这种作用似乎依赖于药物在细胞内的捕获。由于其细胞毒性效力和独特的细胞药物递送原理，对钙黄绿素/AM及相关化合物作为潜在的新型抗癌药物进行进一步研究似乎是有必要的。
