University of Medicine and Dentistry of New Jersey, 185 South Orange Avenue MSB-E650, Newark, NJ 07103, USA.
Mol Cancer Ther. 2010 Nov;9(11):3065-73. doi: 10.1158/1535-7163.MCT-10-0623. Epub 2010 Sep 3.
Despite the initial effectiveness of oncogene-directed cancer therapeutics, acquired drug resistance remains the ultimate "Achilles' heel" for long-term durable remission in cancer patients. Acquisition of drug resistance is not more evident elsewhere than in the use of tyrosine kinase inhibitors, imatinib and dasatinib, for patients with chronic myelogenous leukemia. Hence, even though imatinib initially produces remission in the chronic phase, ultimately these therapeutics fail via the emergence of drug resistance, in which chronic myelogenous leukemia could inevitably progress to a terminal blast phase culminating in fatal outcome. Technically, it is challenging to predict the onset of drug resistance in a small number of oncogene-transformed cells, making the decision of when and how to employ second-generation tyrosine kinase inhibitors, or employ novel compounds that would be of benefit in treating drug-resistant Bcr-Abl mutants mainly retrospective. Here, we characterize a rapid and sensitive real-time fluorescent resonance energy transfer-based assay that is able to detect the in vivo activity of Bcr-Abl and its inhibition by small molecule compounds. Due to its real-time and in vivo nature, such an approach has the potential to monitor a drug-resistant phenotype, as well as to identify pharmaceutical agents that inhibit drug-resistant Bcr-Abl oncoproteins in vivo.
尽管针对致癌基因的癌症治疗在初期非常有效，但获得性耐药仍然是癌症患者长期持久缓解的最终“阿喀琉斯之踵”。在慢性髓性白血病患者中使用酪氨酸激酶抑制剂伊马替尼和达沙替尼时，耐药性的获得比其他任何地方都更为明显。因此，尽管伊马替尼最初能使慢性期缓解，但这些治疗方法最终会因耐药性的出现而失败，慢性髓性白血病不可避免地会进展为终末期的爆炸期，导致致命的后果。从技术上讲，预测少数致癌基因转化细胞中耐药性的发生具有挑战性，因此决定何时以及如何使用第二代酪氨酸激酶抑制剂，或者使用可能有益于治疗耐药 Bcr-Abl 突变体的新型化合物，主要是回顾性的。在这里，我们描述了一种快速灵敏的实时荧光共振能量转移（FRET）检测方法，能够检测体内 Bcr-Abl 的活性及其被小分子化合物的抑制情况。由于其实时和体内的特性，这种方法有可能监测耐药表型，并识别抑制体内耐药 Bcr-Abl 癌蛋白的药物。
