Herein we report the sophisticated process of structural optimization toward a previously disclosed Src inhibitor, compound 1, which showed high potency in the treatment of triple negative breast cancer (TNBC) both in vitro and in vivo but had considerable toxicity. A series of 3-(phenylethynyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine derivatives were synthesized. In vitro cell-based phenotypic screening together with in vivo assays and structure–activity relationship (SAR) studies finally led to the discovery of N-(3-((4-amino-1-(trans-4-hydroxycyclohexyl)-1H-pyrazolo[3,4-d]pyrimidin-3-yl)ethynyl)-4-methylphenyl)-4-methyl-3-(trifluoromethyl)benzamide (13an). 13an is a multikinase inhibitor, which potently inhibited Src (IC₅₀ = 0.003 μM), KDR (IC₅₀ = 0.032 μM), and several kinases involved in the MAPK signal transduction. This compound showed potent anti-TNBC activities both in vitro and in vivo, and good pharmacokinetic properties and low toxicity. Mechanisms of action of anti-TNBC were also investigated. Collectively, the data obtained in this study indicate that 13an could be a promising drug candidate for the treatment of TNBC and hence merits further studies.

中文翻译：

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从铅到药物候选者：3-（苯基乙炔基）-1 H-吡唑并[3,4- d ]嘧啶-4-胺衍生物作为治疗三阴性乳腺癌的药物的优化

本文中，我们报告了针对先前公开的Src抑制剂化合物1进行结构优化的复杂过程，该化合物在体外和体内均显示出对三阴性乳腺癌（TNBC）的高治疗能力，但具有相当大的毒性。合成了一系列的3-（苯基乙炔基）-1 H-吡唑并[3,4- d ]嘧啶-4-胺衍生物。最终基于体外细胞的表型筛选，以及体内测定和结构-活性关系（SAR）研究最终导致了N-（3-（（4-氨基-1-（反式-4-羟基环己基）-1 H）的发现-吡唑并[3,4- d ]嘧啶-3-基）乙炔基）-4-甲基苯基）-4-甲基-3-（三氟甲基）苯甲酰胺（13an）。13an是一种多激酶抑制剂，可有效抑制Src（IC ₅₀ = 0.003μM），KDR（IC ₅₀ = 0.032μM）和几种参与MAPK信号转导的激酶。该化合物在体外和体内均显示出有效的抗TNBC活性，并具有良好的药代动力学特性和低毒性。还研究了抗TNBC的作用机理。总体而言，本研究获得的数据表明13an可能是有希望的TNBC治疗药物，因此值得进一步研究。