Shikonin Attenuates HOTAIR and Akt Signaling Pathway to Attenuate the Epithelial-to-Mesenchymal Transition of Paclitaxel-Resistant Cervical Cancer

Abstract

Objectives: Cervical cancer (CC) is a common gynecologic cancer. Paclitaxel (PTX) is a crucial component of CC chemotherapy, but drug resistance to PTX is a major challenge. Shikonin is known to have an inhibitory effect on various tumors. This study aimed to evaluate the effect of Shikonin on the epithelial-mesenchymal transition (EMT) of PTX-resistant CC cells. Methods: To investigate PTX-resistant CC cells, cells were treated with Shikonin at concentrations of 0, 10, 20, 30, and 40 μM. Cell viability was assessed using the 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and clone formation assays, and cell metastasis was evaluated using a Transwell® assay. Apoptosis was estimated by flow cytometry and the mRNA levels of HOX transcript antisense intergenic RNA (HOTAIR) in cells were measured through a quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein levels of E-cadherin, Vimentin, zinc finger E-box binding homeobox 1 (ZEB1), Bax, B-cell lymphoma-2 (Bcl-2), Caspase-3, cleaved-Caspase-3, c-Myc, Phosphorylated-Akt (p-Akt) and Akt were estimated by Western blot. Results: Shikonin was found to reduce the multiplication and metastasis of PTX-resistant CC cells while increasing cell apoptosis (p < 0.05). Additionally, Shikonin treatment led to a reduction in the HOTAIR mRNA levels in cells (p < 0.05). Shikonin was also found to increase the levels of E-cadherin, Bax and cleaved-Caspase-3/Caspase-3, while reducing the protein levels of Vimentin, Bcl-2, c-Myc and p-Akt (p < 0.05). Finally, it was found that HOTAIR inhibition played a role in the effects of Shikonin on the viability and metastasis of PTX-resistant CC cells (p < 0.05). Conclusions: Overall, Shikonin has been found to have several effects on cancer cells, including reducing the multiplication and metastasis of PTX-resistant CC cells and stimulating apoptosis. These effects may be related to the inhibition of HOTAIR and modulation of the Akt signal pathway.