HER2和EGFR双重抑制剂，如拉帕替尼，对HER2阳性乳腺癌的治疗显示出显着疗效。先前的实验表明，在细胞培养物中，拉帕替尼的功效因暴露于人血清和人表皮生长因子（EGF）而显着降低。在蛋白质组和转录组水平上，我们检查了 HER2 阳性乳腺癌细胞系 SK-BR-3 在单独使用拉帕替尼或与人血清或 EGF 联合治疗后的变化。蛋白质组学分析揭示了 350 种差异表达蛋白 (DEP)，这些蛋白质在诱导细胞生长停滞的浓度下对拉帕替尼治疗产生反应。添加人血清或 EGF 与拉帕替尼组合可防止细胞生长抑制，并且这种组合治疗使人血清和 EGF 的约 93% DEP 的表达恢复至无药物水平。基因本体富集和 OncoboxPD 通路激活水平分析表明，拉帕替尼的添加影响了基于 RNA 和蛋白质的测定中揭示的大多数常见功能过程。然而，在蛋白质组水平上观察到一个具体特征：拉帕替尼的添加增加了与线粒体功能和细胞呼吸相关的蛋白质的表达。当使用 RNA 测序数据进行相同实验时，没有观察到这一特征。然而，这与刃天青测试的结果一致，刃天青测试显示暴露于拉帕替尼后 SK-BR-3 细胞呼吸增加了 1.8 倍。因此，我们得出结论，增强细胞呼吸是拉帕替尼对 HER2 阳性癌细胞的一种新的作用机制。版权所有 © 2024 Kamashev、Shaban、Zakharova、Modestov、Kamynina、Baranov 和 Buzdin。

Dual inhibitors of HER2 and EGFR, such as lapatinib, have shown significant efficacy for the therapy of HER2-positive breast cancer. Previous experiments showed that in cell cultures, the efficacy of lapatinib was significantly reduced by exposure to human serum and human epidermal growth factor (EGF). At the proteomic and transcriptomic levels, we examined the changes in the HER2-positive breast cancer cell line SK-BR-3 profiles upon treatment with lapatinib, either alone or in combination with human serum or EGF. Proteomic profiling revealed 350 differentially expressed proteins (DEPs) in response to lapatinib treatment at concentrations that induced cell growth arrest. Addition of human serum or EGF in combination with lapatinib prevented cell growth inhibition, and this combination treatment returned the expression of ∼93% of DEPs to drug-free levels for both human serum and EGF. Gene ontology enrichment and OncoboxPD pathway activation level analysis showed that lapatinib addition influenced mostly common functional processes revealed in RNA- and protein-based assays. However, a specific feature was observed at the proteome level: addition of lapatinib increased the expression of proteins associated with mitochondrial function and cellular respiration. This feature was not observed when using RNA sequencing data for the same experiments. However, it is consistent with the results of the resazurin test, which showed a 1.8-fold increase in SK-BR-3 cellular respiration upon exposure to lapatinib. Thus, we conclude that enhanced cellular respiration is a novel additional mechanism of action of lapatinib on HER2-positive cancer cells.Copyright © 2024 Kamashev, Shaban, Zakharova, Modestov, Kamynina, Baranov and Buzdin.