The Effects and Mechanism of YK-4-279 in Combination with Docetaxel on Prostate Cancer

Background: Docetaxel is the first-line treatment for castration-resistant prostate cancer (CRPC). The limited survival benefit associated with the quick emergence of resistance and systemic toxicity diminishes its efficacy in high-dose monotherapy. YK-4-279 is a small molecule inhibitor of ETV1 that plays an important role in the progression of prostate cancer. The aim of this study was to evaluate the hypothesis that the combination of docetaxel and YK-4-279 will have a synergistic effect on inhibiting growth and accelerating apoptosis in human prostate cancer cells. Methods: Cell growth assessed using CCK-8 and trypan blue exclusion assays. Cell apoptosis was determined by morphological assessment in cells stained with propidium iodide. Standard scratch migration and Matrigel-coated transwell invasion assays were used to assess cell migration and invasion, respectively. Western blotting was used to investigate the levels of ETV1, AR, PSA, p-STAT3, survivin, Bcl-2, and p-Akt in prostate cancer cells. Results: The combination of low-dose docetaxel and YK-4-279 synergistically inhibited growth and induced apoptosis in human prostate cancer cells. The combination also more efficiently suppressed the migration and invasion of LNCaP and PC-3 cells. The combination of low-dose docetaxel and YK-4-279 caused a stronger decrease in the levels of ETV1, AR, PSA, p-STAT3, survivin, Bcl-2, and p-Akt in LNCaP cells and of p-Akt, Bcl-2, and p-STAT3 in PC-3 cells compared with either drug alone. Conclusions: These data suggest that the combination of docetaxel and YK-4-279 may be an effective approach for inhibiting the growth and metastasis of prostate cancer. This could permit a decrease in the docetaxel dose necessary for patients with CRPC and thereby lower its systemic toxicity.