Prostatic cancer (PCa) is a leading cause of cancer related death in males and is often regarded as a kind of androgen-sensitive cancer. Artesunate (ART), a semi-synthetic derivative of the Chinese herb Artemisia annua, is such an anti-cancer agent. However, the effects and mechanism of ART on PCa cells remains unclear. The study aims to elaborate the mechanism of the involvement of androgen receptor (AR) in antiprostatic cancer (PCa) of artesunate (ART). PCa cells 22rvl were used in vivo and in vitro, and the viability and apoptosis were conducted using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay, respectively. Ectopic expressions of AR and DNA methyltransferase (DNMT) were detected in cells in overexpression or interference of AR or DNMT3b. ART dose-dependently suppressed tumor growth, inhibited cell viability, enhanced apoptosis, decreased AR expression, and increased the expression and the catalytic activity of DNMT3b in 22rv1 cells either in transplanted mice or in vitro. Furthermore, AR downregulated DNMT3b expression, and overexpression of AR or interference of DNMT3b could reverse ART-induced cytotoxicity and apoptosis in 22rvl cells, whereas overexpression of DNMT3b could not change the effect profiles of ART on the cells. The results indicated that ART suppressed tumor growth of prostatic cancer cells through AR-DNMT3b pathway, underlying ART will allow for the utilization of this Chinese therapeutic agent for the potential treatment of prostate cancer.Key words artesunate; prostatic cancer; androgen receptor; DNA methyltransferase; apoptosis Prostatic cancer (PCa) is the most common cause of cancerrelated death in males. Morbidity and mortality of PCa underscore the need for novel treatment options. Although improved therapies have been recently developed to treat and prevent PCa, prostate cancer still remains refractory disease. Lately, herbs and phytochemicals 1) have been attractive as therapeutic agents for tumorigenesis suppression. Understanding how the production of these Chinese herbs is regulated during cancer progression would help develop new cancer therapeutic strategy.Artesunate (ART) is a semi-synthetic derivative of artemisinin, the active principle of the Chinese herb Artemisia annua. ART has been revealed remarkable activity against otherwise multidrug-resistant Plasmodium falciparum and P. vivax malaria. With the recognition of ART, it has now been analyzed for its anti-cancer activity in various tissues-specificity. For example, Tran et al. found that enhancement of ART activity could effectively induce the apoptosis of breast cancer cells.
2)Moreover, ART was proved to be as a novel therapeutic agent for metastatic renal cell carcinoma due to its attenuation action on tumor growth, metastasis.3) Recently, Michaelsen et al. clinically treated PCa patients with long-term Artemisia annua capsules via oral administration combined with shortterm ART inj...