Decrease in paracellular permeability and chemosensitivity to doxorubicin by claudin-1 in spheroid culture models of human lung adenocarcinoma A549 cells
Decrease in paracellular permeability and chemosensitivity to doxorubicin by claudin-1 in spheroid culture models of human lung adenocarcinoma A549 cells
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DOI：
10.1016/j.bbamcr.2018.03.001
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发表时间：
2018-05-01
影响因子：
5.1
通讯作者：
Ikari, Akira
中科院分区：
文献类型：
--
作者：
Akizuki, Risa;Maruhashi, Ryohei;Ikari, Akira
化疗耐药是癌症治疗中的一个主要问题，但其潜在机制尚不完全清楚。我们发现，紧密连接蛋白claudin-1 (CLDN1) 和3 的表达水平在顺铂(CDDP) 耐药的人肺腺癌A549 (A549R) 细胞中上调。 A549R 细胞表现出对阿霉素 (DXR) 的交叉耐药性。在此，检查了CLDN1和3的表达机制和功能。在 A549 和 A549R 细胞中，CLDN1 和 3 主要位于与支架蛋白闭合带 (ZO)-1 相伴的紧密连接处。 A549R细胞中Src、MEK、ERK、c-Fos和Akt的磷酸化水平高于A549细胞。 LY-294002（一种磷酸肌醇 3-激酶 (PI3K) 抑制剂）和 BAY 11-7082（一种 NF-κ B 抑制剂）可降低 CLDN1 和 3 的表达水平。 CLDN1 和 3 的过表达降低了 A549 细胞中 DXR 的细胞旁通透性。在球状培养模型中，A549R 和 CLDN1 过表达细胞 (CLDN1/A549) 的缺氧水平高于 A549、mock/A549 和 CLDN3/A549 细胞。相反，A549R和CLDN1/A549细胞中DXR在球体内部区域的积累和毒性均低于其他细胞。此外，CLDN1 siRNA 在 A549R 细胞中挽救了 DXR 的积累和毒性。我们认为，CDDP 耐药性通过激活 PI3K/Akt/NF-kappa B 通路而上调 CLDN1，从而抑制抗癌药物渗透到球体内部区域。
Chemotherapy resistance is a major problem in the treatment of cancer, but the underlying mechanisms are not fully understood. We found that the expression levels of claudin-1 (CLDN1) and 3, tight junctional proteins, are upregulated in cisplatin (CDDP)-resistant human lung adenocarcinoma A549 (A549R) cells. A549R cells showed cross-resistance to doxorubicin (DXR). Here, the expression mechanism and function of CLDN1 and 3 were examined. CLDN1 and 3 were mainly localized at tight junctions concomitant with zonula occludens (ZO)-1, a scaffolding protein, in A549 and A549R cells. The phosphorylation levels of Src, MEK, ERK, c-Fos, and Akt in A549R cells were higher than those in A549 cells. The expression levels of CLDN1 and 3 were decreased by LY-294002, a phosphoinositide 3-kinase (PI3K) inhibitor, and BAY 11-7082, an NF-kappa B inhibitor. The overexpression of CLDN1 and 3 decreased the paracellular permeability of DXR in A549 cells. Hypoxia levels in A549R and CLDN1-overexpressing cells (CLDN1/A549) were greater than those in A549, mock/A549, and CLDN3/A549 cells in a spheroid culture model. In contrast, accumulation in the region inside the spheroids and the toxicity of DXR in A549R and CLDN1/A549 cells were lower than those in other cells. Furthermore, the accumulation and toxicity of DXR were rescued by CLDN1 siRNA in A549R cells. We suggest that CLDN1 is upregulated by CDDP resistance through activation of a PI3K/Akt/NF-kappa B pathway, resulting in the inhibition of penetration of anticancer drugs into the inner area of spheroids.