*Article* **KIFC1 Inhibitor CW069 Induces Apoptosis and Reverses Resistance to Docetaxel in Prostate Cancer**

**Yohei Sekino 1,2, Naohide Oue 1,\*, Yuki Koike 1, Yoshinori Shigematsu 1,2, Naoya Sakamoto 1, Kazuhiro Sentani 1, Jun Teishima 2, Masaki Shiota 3, Akio Matsubara 2 and Wataru Yasui 1**


Received: 26 December 2018; Accepted: 5 February 2019; Published: 9 February 2019

**Abstract:** Kinesin family member C1 (KIFC1) is a minus end-directed motor protein that plays an essential role in centrosome clustering. Previously, we reported that KIFC1 is involved in cancer progression in prostate cancer (PCa). We designed this study to assess the involvement of KIFC1 in docetaxel (DTX) resistance in PCa and examined the effect of KIFC1 on DTX resistance. We also analyzed the possible role of a KIFC1 inhibitor (CW069) in PCa. We used DTX-resistant PCa cell lines in DU145 and C4-2 cells to analyze the effect of KIFC1 on DTX resistance in PCa. Western blotting showed that KIFC1 expression was higher in the DTX-resistant cell lines than in the parental cell lines. Downregulation of KIFC1 re-sensitized the DTX-resistant cell lines to DTX treatment. CW069 treatment suppressed cell viability in both parental and DTX-resistant cell lines. DTX alone had little effect on cell viability in the DTX-resistant cells. However, the combination of DTX and CW069 significantly reduced cell viability in the DTX-resistant cells, indicating that CW069 re-sensitized the DTX-resistant cell lines to DTX treatment. These results sugges<sup>t</sup> that a combination of CW069 and DTX could be a potential strategy to overcome DTX resistance.

**Keywords:** KIFC1; prostate cancer; docetaxel resistance; apoptosis; CW069
