Department of Physiology & Medical Science, Chungnam National University School of Medicine, Daejeon, Republic of Korea.
Department of thoracic surgery, Chungnam National University School of Medicine, Daejeon, Republic of Korea.
Anticancer Res. 2024 Sep;44(9):3867-3874. doi: 10.21873/anticanres.17213.
BACKGROUND/AIM: Macrophages prevail in the microenvironment of several tumors, including non-small-cell lung cancer (NSCLC), where they secrete pro-tumorigenic factors that contribute to cancer progression. This study investigated the role of macrophages on the resistance of epidermal growth factor receptor (EGFR)-mutated NSCLC cells to tyrosine kinase inhibitors (TKIs).
EGFR-mutated cell lines PC-9 and HCC827 were cocultured with macrophages and treated with TKIs (erlotinib and gefitinib). The effects of the macrophage-conditioned medium (macrophage CM) on gefitinib resistance and cell migration were also evaluated.
Co-culture with macrophages significantly enhanced the resistance to erlotinib and gefitinib in PC-9 and HCC827 cells compared to that in cells cultured independently. Macrophage CM markedly induced gefitinib resistance in PC-9 cells, with maximum resistance observed at 50% CM concentration. This resistance persisted for up to 48 h post-CM removal. Macrophage CM inhibited gefitinib-induced apoptosis, as evidenced by the decreased expression of cleaved caspase-3, PARP, and BIM. Additionally, macrophage CM increased the migration ability of PC-9 cells, as shown by the wound healing and transwell migration assays. Studies have shown that TonEBP is crucial in cancer metastasis and drug resistance; we found that inhibition of TonEBP/NFAT5 expression reduced gefitinib resistance and migration in macrophage CM-induced PC-9 cells, indicating its role as mediator of these effects.
Macrophages contribute to TKI resistance and enhance the migration of EGFR-mutated NSCLC cells through mechanisms involving TonEBP/NFAT5. Therefore, targeting TonEBP/NFAT5 represents a potential therapeutic strategy for overcoming macrophage-induced TKI resistance in NSCLC cells.
背景/目的：巨噬细胞存在于多种肿瘤的微环境中，包括非小细胞肺癌（NSCLC），它们分泌的促肿瘤因子有助于癌症进展。本研究探讨了巨噬细胞在表皮生长因子受体（EGFR）突变型 NSCLC 细胞对酪氨酸激酶抑制剂（TKI）耐药中的作用。
将 EGFR 突变细胞系 PC-9 和 HCC827 与巨噬细胞共培养，并使用 TKI（厄洛替尼和吉非替尼）进行处理。还评估了巨噬细胞条件培养基（macrophage CM）对吉非替尼耐药和细胞迁移的影响。
与独立培养的细胞相比，与巨噬细胞共培养显著增强了 PC-9 和 HCC827 细胞对厄洛替尼和吉非替尼的耐药性。巨噬细胞 CM 显著诱导了 PC-9 细胞对吉非替尼的耐药性，在 50%CM 浓度时达到最大耐药性。这种耐药性在 CM 去除后持续长达 48 小时。巨噬细胞 CM 抑制了吉非替尼诱导的细胞凋亡，表现为 cleaved caspase-3、PARP 和 BIM 的表达减少。此外，巨噬细胞 CM 增加了 PC-9 细胞的迁移能力，划痕愈合和 Transwell 迁移实验均表明了这一点。研究表明，TonEBP 在癌症转移和耐药中起关键作用；我们发现，抑制 TonEBP/NFAT5 的表达降低了巨噬细胞 CM 诱导的 PC-9 细胞中的吉非替尼耐药性和迁移，表明其作为这些作用的介导物的作用。
巨噬细胞通过涉及 TonEBP/NFAT5 的机制促进 TKI 耐药并增强 EGFR 突变型 NSCLC 细胞的迁移。因此，靶向 TonEBP/NFAT5 可能是克服 NSCLC 细胞中巨噬细胞诱导的 TKI 耐药的潜在治疗策略。
