Mallon Robert, Feldberg Larry, Kim Steven, Collins Karen, Wojciechowicz Donald, Kohler Constance, Kovacs Diana, Discafani Carolyn, Zhang Nan, Wu Biqi, Floyd Brawner, Powell Dennis, Berger Dan
Oncology Research, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965, USA.
Mol Cancer Ther. 2004 Jun;3(6):755-62.
A high-throughput screen for Ras-mitogen-activated protein kinase (MAPK) signaling inhibitors identified two series (class 1 and 2) of substituted 4-anilino-3-quinolinecarbonitriles as potent (IC(50)s <10 nmol/L) mitogen-activated protein/extracellular signal-regulated kinase 1 (MEK1) kinase inhibitors. These compounds had cyanoquinoline cores, but differed in their respective aniline groups [1a, 1b: 4-phenoxyphenylaniline; 2a, 2b: 3-chloro-4-(1-methylimidazol-2-sulfanyl)aniline]. These compounds were competitive inhibitors of ATP binding by MEK1 kinase, and they had minimal or no effect on Raf, epidermal growth factor receptor (EGFR), Akt, cyclin-dependent kinase 4 (CDK4), or MK2 kinases at concentrations >100-fold higher than those that inhibited MEK1 kinase. Both class 1 and 2 compounds inhibited in vitro growth of human tumor cell lines. A class 2 compound (2b) was the most potent inhibitor of human tumor cell growth in vitro, and this effect was linked to distinct suppression of MAPK phosphorylation in cells. Compound 2b did not affect phosphorylation status of other kinases, such as EGFR, Akt, and stress-activated protein (SAP)/c-jun-NH kinase (Jnk); nor did it affect overall tyrosine phosphorylation level in cells. However, compound 2b did inhibit MEK1 phosphorylation in cells. Inhibition of MEK1 phosphorylation by 2b was not due to a major effect on Raf kinase activity, because enzyme assays showed minimal Raf kinase inhibition. We believe compound 2b inhibits kinase activity upstream of Raf, and thereby affects MEK1 phosphorylation in cells. Even with the dual effect of 2b on MEK and MAPK phosphorylation, this compound was well tolerated and significantly inhibited growth of the human colon tumor cell line LoVo (at 50 and 100 mg/kg BID, i.p.) in a nude mouse xenograft model.
一项针对Ras-丝裂原活化蛋白激酶（MAPK）信号抑制剂的高通量筛选，鉴定出两类（1类和2类）取代的4-苯胺基-3-喹啉腈作为有效的（半数抑制浓度（IC50）<10 nmol/L）丝裂原活化蛋白/细胞外信号调节激酶1（MEK1）激酶抑制剂。这些化合物具有氰基喹啉核心，但各自的苯胺基团不同[1a、1b：4-苯氧基苯基苯胺；2a、2b：3-氯-4-（1-甲基咪唑-2-硫烷基）苯胺]。这些化合物是MEK1激酶ATP结合的竞争性抑制剂，在浓度比抑制MEK1激酶的浓度高100倍以上时，它们对Raf、表皮生长因子受体（EGFR）、Akt、细胞周期蛋白依赖性激酶4（CDK4）或MK2激酶的影响极小或无影响。1类和2类化合物均抑制人肿瘤细胞系的体外生长。2类化合物（2b）是体外人肿瘤细胞生长的最有效抑制剂，这种作用与细胞中MAPK磷酸化的明显抑制有关。化合物2b不影响其他激酶的磷酸化状态，如EGFR、Akt和应激激活蛋白（SAP）/c-Jun氨基末端激酶（Jnk）；也不影响细胞中的总体酪氨酸磷酸化水平。然而，化合物2b确实抑制细胞中的MEK1磷酸化。2b对MEK1磷酸化的抑制不是由于对Raf激酶活性的主要影响，因为酶分析显示Raf激酶抑制作用极小。我们认为化合物2b抑制Raf上游的激酶活性，从而影响细胞中的MEK1磷酸化。即使2b对MEK和MAPK磷酸化有双重作用，该化合物在裸鼠异种移植模型中仍具有良好的耐受性，并显著抑制人结肠肿瘤细胞系LoVo的生长（腹腔注射，每日两次，50和100 mg/kg）。
