Thus, an ongoing, large-scale effort is underway to develop clinically active drugs that target elements of the PI3K pathway. However, conflicting data suggest that gain-of-function PIK3CA mutations may be associated with either a favorable or a poor clinical outcome, compared with the wild-type PIK3CA gene. In the current study, we performed a systematic review of breast cancer clinical studies. Upon evaluation of 2587

breast cancer cases from 12 independent studies, we showed that patients with tumors harboring a PIK3CA mutation have a better clinical outcome than those with a wild-type PIK3CA gene. Importantly, this improved prognosis may pertain only to patients with mutations in the kinase domain of p110α and to postmenopausal women with MLN2238细胞系 estrogen receptor-positive breast cancer. We propose three potential explanations for this paradoxical observation. First, PIK3CA mutations may interfere with the metastasis process or may induce senescence, which results in a better

outcome for patients with mutated tumors. Secondly, we speculate that PIK3CA mutations may increase early tumor diagnosis by modification of the actin cytoskeleton in tumor cells. Lastly, we propose that PIK3CA mutations may be a favorable predictive factor for response to hormonal Erlotinib体内 therapy, giving a therapeutic advantage to these patients. Ultimately, an improved understanding of the clinical

impact of PIK3CA mutations is critical for the development 什么 of optimally personalized therapeutics against breast cancer and other solid tumors. This effort will be important to prevent or explain therapeutic failures and select patients who are most likely to respond to new therapies that inhibit the PI3K pathway.
磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT/PKB)/哺乳动物雷帕霉素靶蛋白(mTOR)信号传导通路可抑制肿瘤细胞凋亡、促进细胞生存、调节细胞周期,促进肿瘤新生血管的形成以及侵袭与转移,在肿瘤的发生、发展、治疗及转归中发挥着重要作用。而近来研究发现此信号通路与乳腺癌的关系非常密切,使之成为乳腺癌新的治疗靶点及研究热点。临床前研究已经证实,PI3K抑制剂及mTOR抑制剂通过不同的作用靶点作用于PI3K/AKT/mTOR信号传导通路上,从而达到抗癌的作用。PI3K抑制剂中有些药物只作用于PI3K靶点,有些作用于PI3K和mTOR双靶点,且现阶段的研究更倾向于进行针对不同PI3K亚型的分子靶向药物的研究,以达到对PI3K通路的抑制作用更具有针对性和特异性的目的,其在临床上的作用和疗效需要进行进一步的研究。而mTOR抑制剂针对的作用靶点是mTORC1,是PI3K/AKT/mTOR通路中开发较为完善的分子靶向药物,雷帕霉素衍生物类药物已经在乳腺癌中进行Ⅱ/Ⅲ期临床试验,且该类药物在联合乳腺癌内分泌治疗药物或人表皮生长因子受体-2(Her-2)靶向治疗药物治疗转移性乳腺癌中取得了良好的疗效。
目的设计合成一系列6-取代亚甲肼基嘧啶及三嗪衍生物,并对其体外抗肿瘤活性进行初步评价。方法以2,4,6-三氯嘧啶或三聚氯氰、苯胺、苯并咪唑、吡咯为起始原料,经多步反应合成目标化合物;采用MTT法,以BMCL-200908069-1为阳性对照药,以H460、A549和H226为测试细胞株,对目标化合物进行抗肿瘤活性评价。结果合成了20个未见文献报道的6-取代亚甲肼基-2,4-双吗啉嘧啶及三嗪类化合物,其结构经MS、1H-NMR谱确证。结论体外活性实验显示:该系列化合物具有较强的抗肿瘤活性,其中,化合物6a活性最佳,其对H460、A549和H226抑制作用的IC50值分别为3.4、0.75、0.86μmol.L-1,其活性为阳性对照药的2.8～16.