Objective: Prostate cancer (PCa) is the most common malignant tumor diagnosed in men in developed countries. In developing countries, the PCa morbidity and mortality rates are also increasing rapidly. Since androgen receptor (AR) is a key driver and plays a critical role in the regulation of PCa development, AR-targeted agents provide a key component of current therapy regimens. However, even new-generation AR antagonists are prone to drug resistance, and there is currently no effective strategy for overcoming advanced PCa aggressiveness, including drug-resistance progression. The aim of this study was to evaluate the potential efficacy and novel therapy strategy of proxalutamide (a newly developed AR antagonist) in PCa. Methods: Four PCa cell lines with various biological heterogeneities were utilized in this study, namely, androgen-sensitive/-insensitive with/without AR expression. Proliferation, migration and apoptosis assays in PCa cells were used to evaluate the effective therapeutic activity of proxalutamide. The changes in lipid droplet accumulation and lipidomic profiles were analyzed to determine the influence of proxalutamide on lipogenesis in PCa cells. The molecular basis of the effects of proxalutamide on lipogenesis and the AR axis was then further investigated. Results: Proxalutamide significantly inhibited the proliferation and migration of PCa cells, and its inhibitory effect was superior to that of enzalutamide (Enz, second-generation AR antagonist). Proxalutamide induced the caspase-dependent apoptosis of PCa cells. Proxalutamide significantly diminished the level of lipid droplets in PCa cells, changed the lipid profile of PCa cells and reduced the content of most lipids (especially triglycerides) in PCa cells. Proxalutamide attenuated de novo lipogenesis by inhibiting the expression of ATP citrate lyase (ACL), acetyl CoA carboxylase (ACC), fatty acid synthase (FASN) and sterol regulatory element-binding protein-1 (SREBP-1). Moreover, proxalutamide also decreased AR expression in PCa cells, and its inhibitory effect on lipogenesis did not depend on its ability to down-regulate AR expression. However, Enz had no effect on AR expression, lipid accumulation or lipid de novo synthesis in PCa cells. Conclusions: By co-targeting the AR axis and endogenous adipogenesis, a novel and promising strategy was established for proxalutamide to combat the progress of PCa. The unique effect of proxalutamide on the metabolic reprogramming of PCa provides a potential solution to overcome the resistance of current AR-targeted therapy, which will help to effectively prolong its clinical service life.

Background The application of neoadjuvant docetaxel and androgen deprivation therapy before radical prostatectomy has been clinically recognized as beneficial for the overall and progression‐free survival of patients with advanced prostate cancer. However, the mechanism underlying its clinical efficacy has not yet been reported. Methods We conducted a randomized comparative study on about 100 patients with high‐risk localized prostate cancer. Through nontarget metabolomics and tissue microarray immunohistochemistry, we investigated the difference in the endogenous metabolism of tumors in patients with prostate cancer who received or did not receive the neoadjuvant therapy. Results Many endogenous metabolic pathways, especially nucleotide synthesis, glutathione metabolism, citric acid cycle, and lipid synthesis, in prostate cancer tissue were altered after the neoadjuvant treatment, and the levels of nearly 90% of the differentially regulated metabolites were significantly decreased. Moreover, the levels of key enzymes in the cellular energy pathways were downregulated in tumor tissues and upregulated in adjacent tissues after the treatment. The positive and negative effects of the neoadjuvant therapy on normal and tumor cells in the prostate, respectively, resulted in the activation of the former and inhibition of the latter, which helped in reducing the number of tumors and weakened their aggressiveness. Conclusions From the perspective of endogenous metabolism in tumors, we have confirmed that neoadjuvant therapy can significantly downregulate important pathways for biosynthesis and energy metabolism in prostate cancer tissue, and thereby, inhibit tumor growth and metastasis.