Dongguan Institute of Clinical Cancer Research, Affiliated Dongguan People's Hospital, Southern Medical University, Dongguan, China.
Department of Pathology, Gaozhou People's Hospital, Maoming, China.
BMC Pulm Med. 2021 May 15;21(1):163. doi: 10.1186/s12890-021-01540-4.
ID1 is associated with resistance to the first generation of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, the effect of ID1 expression on osimertinib resistance in EGFR T790M-positive NSCLC is not clear.
We established a drug-resistant cell line, H1975/OR, from the osimertinib-sensitive cell line H1975. Alterations in ID1 protein expression and Epithelial-mesenchymal transition (EMT)-related proteins were detected with western blot analysis. RT-PCR was used to evaluate the differences of gene mRNA levels. ID1 silencing and overexpression were used to investigate the effects of related gene on osimertinib resistance. Cell Counting Kit-8 (CCK8) was used to assess the proliferation rate in cells with altered of ID1 expression. Transwell assay was used to evaluate the invasion ability of different cells. The effects on the cell cycle and apoptosis were also compared using flow cytometry.
In our study, we found that in osimertinib-resistant NSCLC cells, the expression level of the EMT-related protein E-cadherin was lower than that of sensitive cells, while the expression level of ID1 and vimentin were higher than those of sensitive cells. ID1 expression levels was closely related to E-cadherin and vimentin in both osimertinib-sensitive and resistant cells. Alteration of ID1 expression in H1975/OR cells could change the expression of E-cadherin. Downregulating ID1 expression in H1975/OR cells could inhibit cell proliferation, reduce cell invasion, promote cell apoptosis and arrested the cell cycle in the G1/G0 stage phase. Our study suggests that ID1 may induce EMT in EGFR T790M-positive NSCLC, which mediates drug resistance of osimertinib.
Our study revealed the mechanism of ID1 mediated resistance to osimertinib in EGFR T790M-positive NSCLC through EMT, which may provide new ideas and methods for the treatment of EGFR mutated NSCLC after osimertinib resistance.
ID1 与非小细胞肺癌（NSCLC）中第一代 EGFR 酪氨酸激酶抑制剂（EGFR-TKIs）的耐药性有关。然而，ID1 表达对 EGFR T790M 阳性 NSCLC 对奥希替尼耐药的影响尚不清楚。
我们从奥希替尼敏感细胞系 H1975 中建立了耐药细胞系 H1975/OR。用 Western blot 分析检测 ID1 蛋白表达和上皮-间质转化（EMT）相关蛋白的变化。RT-PCR 用于评估基因 mRNA 水平的差异。ID1 沉默和过表达用于研究相关基因对奥希替尼耐药的影响。细胞计数试剂盒-8（CCK8）用于评估改变 ID1 表达的细胞的增殖率。Transwell 测定用于评估不同细胞的侵袭能力。还通过流式细胞术比较了对细胞周期和凋亡的影响。
在我们的研究中，我们发现奥希替尼耐药 NSCLC 细胞中 EMT 相关蛋白 E-钙黏蛋白的表达水平低于敏感细胞，而 ID1 和波形蛋白的表达水平高于敏感细胞。ID1 表达水平与奥希替尼敏感和耐药细胞中的 E-钙黏蛋白和波形蛋白密切相关。改变 H1975/OR 细胞中的 ID1 表达可改变 E-钙黏蛋白的表达。下调 H1975/OR 细胞中的 ID1 表达可抑制细胞增殖、减少细胞侵袭、促进细胞凋亡并将细胞周期阻滞在 G1/G0 期。我们的研究表明，ID1 可能通过 EMT 诱导 EGFR T790M 阳性 NSCLC 中的 EMT，从而介导奥希替尼耐药。
我们的研究通过 EMT 揭示了 ID1 介导的 EGFR T790M 阳性 NSCLC 对奥希替尼耐药的机制，这可能为奥希替尼耐药后 EGFR 突变型 NSCLC 的治疗提供新的思路和方法。
