Kohn E C, Felder C C, Jacobs W, Holmes K A, Day A, Freer R, Liotta L A
Laboratory of Pathology, NCI, Bethesda, Maryland.
Cancer Res. 1994 Feb 15;54(4):935-42.
Evidence is accumulating that calcium homeostasis and calcium-regulated events may be selectively important in generation and maintenance of the malignant phenotype. CAI, a carboxyamido-triazole with a halogenated benzophenone tail, is a novel inhibitor of receptor-operated calcium influx and arachidonic acid release which inhibits malignant proliferation, invasion, and metastasis. The focus of this investigation was structural analysis of CAI and to determine if the inhibition of calcium influx and arachidonic acid release by CAI and its antiproliferative activity were mediated through the same chemical domains. Four families of molecular modifications of the CAI parent were synthesized: (I) modification or substitution of the triazole ring; (II) removal of the substituted benzophenone tail; (III) dehalogenation or partial truncation of the benzophenone moiety; and (IV) removal of the triazole and altered substitutions of the benzophenone tail. Compounds were tested for the inhibition of calcium influx and arachidonic acid release and inhibition of proliferation and colony formation in soft agar using the malignant CHO line transfected with the m5 muscarinic receptor and the A2058 human melanoma cell line. Only CAI and Group I compounds inhibited stimulated calcium influx, arachidonic acid release, and proliferation. Linear regression analysis of the relationship of the 50% inhibitory concentration values for all compounds in inhibition of calcium influx and arachidonate release was statistically significant (r2 = 0.993). Similarly, a linear relationship was demonstrated between inhibition of calcium influx and inhibition of tumor cell proliferation (r2 = 0.971). Groups II-IV had minimal or no signal or growth inhibitory activity. This investigation provides the first evidence for a coordinate link between calcium influx, calcium-mediated arachidonic acid release, and malignant proliferation and metastasis and constitutes the initial analysis of structurally important domains of the CAI molecule.
越来越多的证据表明，钙稳态和钙调节事件在恶性表型的产生和维持中可能具有选择性重要意义。CAI是一种带有卤代二苯甲酮尾部的羧酰胺基三唑，是一种新型的受体操纵性钙内流和花生四烯酸释放抑制剂，可抑制恶性增殖、侵袭和转移。本研究的重点是对CAI进行结构分析，并确定CAI对钙内流和花生四烯酸释放的抑制作用及其抗增殖活性是否通过相同的化学结构域介导。合成了CAI母体的四个分子修饰家族：（I）三唑环的修饰或取代；（II）去除取代的二苯甲酮尾部；（III）二苯甲酮部分的脱卤或部分截短；（IV）去除三唑并改变二苯甲酮尾部的取代基。使用转染了m5毒蕈碱受体的恶性CHO细胞系和A2058人黑色素瘤细胞系，测试了化合物对钙内流和花生四烯酸释放的抑制作用以及对软琼脂中增殖和集落形成的抑制作用。只有CAI和I组化合物抑制刺激的钙内流、花生四烯酸释放和增殖。对所有化合物抑制钙内流和花生四烯酸释放的50%抑制浓度值之间的关系进行线性回归分析，具有统计学意义（r2 = 0.993）。同样，在钙内流抑制和肿瘤细胞增殖抑制之间也显示出线性关系（r2 = 0.971）。II-IV组具有最小或无信号或生长抑制活性。本研究为钙内流、钙介导的花生四烯酸释放与恶性增殖和转移之间的协同联系提供了首个证据，并构成了对CAI分子结构重要结构域的初步分析。
