National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
Hum Mutat. 2012 Nov;33(11):1566-75. doi: 10.1002/humu.22145. Epub 2012 Jul 16.
Aberrant activation of receptor tyrosine kinases (RTKs) is a common feature of many cancer cells. It was previously suggested that the mechanisms of kinase activation in cancer might be linked to transitions between active and inactive states. Here, we estimate the effects of single and double cancer mutations on the stability of active and inactive states of the kinase domains from different RTKs. We show that singleton cancer mutations destabilize active and inactive states; however, inactive states are destabilized more than the active ones, leading to kinase activation. We show that there exists a relationship between the estimate of oncogenic potential of cancer mutation and kinase activation. Namely, more frequent mutations have a higher activating effect, which might allow us to predict the activating effect of the mutations from the mutation spectra. Independent evolutionary analysis of mutation spectra complements this observation and finds the same frequency threshold defining mutation hotspots. We analyze double mutations and report a positive epistasis and additional advantage of doublets with respect to cancer cell fitness. The activation mechanisms of double mutations differ from those of single mutations and double mutation spectrum is found to be dissimilar to the mutation spectrum of singletons.
受体酪氨酸激酶(RTKs)的异常激活是许多癌细胞的共同特征。先前有人提出,癌症中激酶激活的机制可能与活性和非活性状态之间的转换有关。在这里,我们估计单癌突变和双癌突变对不同 RTK 的激酶结构域的活性和非活性状态稳定性的影响。我们表明,单癌突变会使活性和非活性状态失稳;然而,非活性状态的失稳程度超过活性状态,导致激酶激活。我们表明,癌症突变的致癌潜力估计与激酶激活之间存在关系。即,更频繁的突变具有更高的激活作用,这可能使我们能够根据突变谱预测突变的激活作用。对突变谱的独立进化分析补充了这一观察结果,并发现了定义突变热点的相同频率阈值。我们分析了双突变,并报告了正的上位效应,以及双突变体相对于癌细胞适应性的额外优势。双突变的激活机制与单突变不同,并且双突变谱与单突变体的突变谱不同。