ZEB1 Contributes to Drug Resistance Through Canonical Wnt Signaling in Lung Cancer.

Lung cancer is a severe malignant disease and causes plenty of deaths each year. The survival and prognosis are disappointing for patients with recurrence or metastasis. This is partially due to the lack of mechanisms underlying lung cancer. The ZEB1 gene was reported to promote progression in lung cancer. However, the mechanism of ZEB1 in lung cancer is a puzzle. ZEB1 and WNT7B were expressed more strongly in lung cancer cells. In clinical lung cancer tissues, ZEB1 was also overexpressed compared to the adjacent normal tissues. ZEB1 knockdown (ZEB1-KD) inhibited the activation of Wnt/β-catenin signaling. However, overexpression of WNT7B alleviated this inhibition. Furthermore, ZEB1 was shown to regulate the expression of WNT7B, and WNT7B was the bridge between ZEB1 and Wnt signaling. Cell proliferation and invasion ability were inhibited by ZEB1-KD, which was reversed by WNT7B overexpression. This regulation was supported by the expression patterns of PCNA, E-cadherin, and N-cadherin. In addition, much more cell apoptosis was induced in ZEB1-KD cells treated with Docetaxel compared to that without ZEB1-KD. This induction was reversed when WNT7B was overexpressed. Consistently, the IC50 value in the ZEB1-KD/Docetaxel group was much lower than that in the ZEB1-KD or Docetaxel alone group. In contrast, WNT7B overexpression increased the IC50 value of Docetaxel. In conclusion, ZEB1 positively regulates Wnt/β-catenin signaling in lung cancer and contributes to cancer progression. ZEB1 knockdown increases the efficacy of Docetaxel in lung cancer.