Department of Medical Oncology, Xuzhou Central Hospital, Xuzhou Medical University, Xuzhou, P.R. China.
Department of Respiratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, P.R. China.
Oncol Res. 2019 Jul 12;27(7):751-761. doi: 10.3727/096504018X15372657298381. Epub 2019 Feb 7.
Acquired resistance remains a key challenge in epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) therapy in lung adenocarcinoma (LUAD). Recent studies have shown that Notch signaling is associated with drug resistance. However, its role and possible mechanisms in EGFR-TKI resistance are not yet clear. In our study, we found that among four members of NOTCH1-4, only NOTCH3 was upregulated in LUAD tissues and TKI-resistant cell line (HCC827GR6). Knockdown of NOTCH3 by siRNA significantly inhibited proliferative ability, and decreased colony and sphere formation in HCC827GR6 cells. Then miR-150 was identified as a posttranscriptional regulator of NOTCH3. Its expression was downregulated in LUAD tissues and negatively correlated with NOTCH3 mRNA. The cell proliferation and IC of gefitinib were decreased in HCC827GR6 cells transfected with miR-150 mimic, but was reversed when cotransfected with NOTCH3 overexpressed vector. Moreover, we also enrolled 20 patients with advanced LUAD who have taken TKIs as first-line therapy in this study. We found that collagen 1A1 (COL1A1) expression was increased significantly in LUAD tissues both at mRNA and protein levels, and positively correlated with NOTCH3 expression verified in our data and TCGA data. Univariate survival analysis showed that patients with high protein expression of NOTCH3 or COL1A1 were associated with shorter overall survival (OS). Taken together, these results suggest that miR-150/NOTCH3/COL1A1 axis contributed to EGFR-TKI resistance in LUAD, which provide a potential therapeutic target for LUAD treatment.
获得性耐药仍是肺腺癌（LUAD）表皮生长因子受体（EGFR）-酪氨酸激酶抑制剂（TKI）治疗的关键挑战。最近的研究表明，Notch 信号通路与耐药性相关。然而，其在 EGFR-TKI 耐药中的作用和可能的机制尚不清楚。在我们的研究中，我们发现，在 NOTCH1-4 的四个成员中，只有 NOTCH3 在 LUAD 组织和 TKI 耐药细胞系（HCC827GR6）中上调。用 siRNA 敲低 NOTCH3 可显著抑制 HCC827GR6 细胞的增殖能力，并降低集落和球体形成。然后确定 miR-150 是 NOTCH3 的转录后调节因子。它在 LUAD 组织中的表达下调，与 NOTCH3 mRNA 呈负相关。在 HCC827GR6 细胞中转染 miR-150 模拟物后，细胞增殖和吉非替尼的 IC 降低，但与过表达 NOTCH3 载体共转染时则逆转。此外，我们还招募了 20 名接受 TKI 作为一线治疗的晚期 LUAD 患者进行这项研究。我们发现，COL1A1 在 LUAD 组织中的 mRNA 和蛋白水平均显著增加，与我们的数据和 TCGA 数据中验证的 NOTCH3 表达呈正相关。单因素生存分析显示，NOTCH3 或 COL1A1 蛋白高表达的患者总生存期（OS）较短。总之，这些结果表明，miR-150/NOTCH3/COL1A1 轴参与了 LUAD 的 EGFR-TKI 耐药，为 LUAD 的治疗提供了一个潜在的治疗靶点。
