Qi Ling decoction enhances abiraterone treatment via suppression of autophagy in castration resistant prostate cancer

Abiraterone acetate has exhibited impressive results in improving progression-free survival of patients with metastatic castration-resistant prostate cancer. However, many patients may develop abiraterone resistance with a variable duration of response. Hence, identifying a remedy to overcome abiraterone resistance is critical for patients with castration-resistant prostate cancer. In this study, we aim to explore the potential of Qi Ling decoction (QLD), a traditional Chinese medicine, in attenuating abiraterone resistance in prostate cancer. Cell viability and apoptosis were respectively measured by Cell Counting Kit-8 (CCK-8) assay and flow cytometry. The protein levels were assessed by Western blotting assay. Autophagosome formation was quantified by counting LC3 puncta. We found that QLD was capable of promoting abiraterone-induced apoptosis and cell death of PC3-AbiR and DU145-AbiR cells in vitro. A combination of QLD and abiraterone yielded a better tumor inhibition effect than QLD alone and abiraterone alone. Further investigation revealed that QLD restored the abiraterone sensitivity of PC3-AbiR and DU145-AbiR cells through modulating autophagy. These findings suggest that QLD might serve as a potential remedy to enhance the therapeutical effect of abiraterone for patients with castration-resistant prostate cancer.