KLF5 influences cell biological function and chemotherapy sensitivity through the JNK signaling pathway in anaplastic thyroid carcinoma.

We aimed to investigate the effects of Krüppel-like factor 5 (KLF5) on cell biological function and chemotherapy sensitivity of anaplastic thyroid carcinoma (ATC) and explore the underlying mechanism. In this study, we found that KLF5 was expressed higher in ATC cells than that in normal thyroid cells. Knockdown of KLF5 inhibited proliferation, induced apoptosis and restrained invasion and migration abilities of ATC cells. KLF5 overexpression promoted proliferation and inhibited apoptosis of ATC cells in response to doxorubicin (Dox), whereas KLF5 knockdown increased the sensitivity of ATC cells to Dox. Multidrug resistance gene 1/permeability glycoprotein and ATP-binding cassette superfamily G member 2 were heightened in ATC cells with KLF5 overexpression, but the opposite results were found in sh-KLF5-treated cells. Phosphorylation (p)-c-Jun N-terminal kinase (JNK) was upregulated in KLF5 overexpression cells, whereas it was downregulated in the KLF5 knockdown treatment group. Furthermore, KLF5 knockdown inhibited ATC growth and enhanced the Dox sensitivity of ATC by inactivating the JNK signaling pathway. Taken together, our findings concluded that KLF5 knockdown can remarkably inhibit the proliferation, invasion, and migration and induce apoptosis of ATC cells, and increase the chemotherapy sensitivity of ATC, all of which probably through inhibiting the JNK signaling pathway.