Epimedium Glycoside Lncap Cell Function And Ar For Prostate Cancer Related Molecular Mechanism

Objectives:Prostate cancer is the most common and the first killer of all the fatal tumors among United States males. China has witnessed a dramatic increase in prostate cancers in recent years, making it the third leading culprit in deadly tumors among males in our country. Despite the effectiveness of androgen deprivation therapy in the initial stage, it fails to function well because of its transformation into androgen-independent prostate cancer in the ultimate phase. Traditional Chinese medicine has played a vital role in treating the prostate cancer by delaying its transformation into androgen-independent type and has some effects.Traditional Chinese Medicine holds that the pathogenesis of prostate cancer is deficiency of the kidney, so kidney-tonifying herbs and other adjuvant herbs are administered according to various patterns of syndromes. However, some kidney-tonifying herbs which may have testosterone mimetic properties might exacerbate the prostate cancer in the initial stage during which it is androgen-dependent.Therefore, there is a great controversy whether it is proper to take kidney-tonifying herbs to treat prostate cancer. And, it is essential to judge kidney-tonifying herbs’effectiveness according to their impact on the growth of prostate cells. ICariin, ICa is a flavonoid isolated from the plant Herba epimedii, which is widely used as a kidney-tonifying drug in traditional Chinese medicine (TCM) for centuries. Pharmacological studies have showed that ICa has inhibitory effects on a wide variety of tumor cells, Also, it increases the weights of testis and epididymis and the testosterone concentration in immature male rats, and has testosterone mimetic properties. So in this study, we investigate ICa’s effect on the antrogen-dependent LNCaP cells and whether it has some molecular correlation with androgen receptor(AR),and ultimately aim to providing experimental back ups for lea in treating prostate cancers.Methods:We cultivated LNCaP cells, a cell strain of prostate cancer, in vitro, and then treated them with ICa of different concentrations at various times, after which a series of detections were performed.1. To study the effects of ICa on LNCaP’s proliferation:according to MTT protocol, we evaluated LNCaP"s proliferation rate when treated with ICa of various concentrations for24h and48h respectively. Testosterone Undecanoate was set as a positive control.2To study the effects of ICa on LNCaP’s cell cycle and cell apoptosis:we evaluated cell cycles using cytometry (PI simple staining) and the cell apoptosis using cytometry (FITC/PI double staining) after the treatments last for48h.3. To study the effects of ICa on AR and PSA in LNCaP:we study the effects of ICa of various concentrations on LNCaP cells when the treatment last for48h, western blotting was used to detect expression of AR protein and PSA protein;immunofluorescence was used to detect he AR nuclear translocation.4. To study the effects of ICa on the HER2-PI3K-Akt pathway of LNCaP cells:after48h of treatment, the effects of ICa of different concentrations on LNCaP cells were evaluated; HER2, p-HER2, Akt and p-Akt expression level was detected by westem-blotting.Result1. Parallel-controlled drug Testosterone Undecanoate have two-way regulating effects on LNCaP cell proliferation, relative higher concentrations (10-5mol/L,10-6mol/L,10-7mol/L) inhibit cell proliferation, relative lower concentrations (10-8mol/L,10-9mol/L,10-10mol/L) promote cell proliferation; ICa inhibited LNCaP cell growth (final concentration10-6mol/L the highest inhibition rate is31.98%,48h). Compared with the ones at24h,48h inhibition rates are far higher.(P<0.05).2. Further analyses by flow cytometry showed that ICa which treated the LNCaP cells for48h can stagnate G0/G1phase and block the cells entry into S Phase, however, GZ/M Phase had no significant change,. Meanwhile cell apoptosis both in the early and advanced stages were low (concentration of ICa of10-6mol/L apoptosis rate in the early stage was0.13%, the apoptosis rate in the advanced stage was1.8%), and ICa can’t induce apoptosis in LNCaP cells.3. ICa (final concentration10-6mol/L, relative ratio is0.24, control group is1.17) reduced AR protein expression significantly in LNCaP cells, and suppress nuclear translocation of AR in a complete contrast with the parallel-controlled drug-Testosterone Undecanoate; ICa (final concentration10-6mol/L) also inhibited PSA protein expression of LNCaP cells significantly.4. ICa can significantly reduce the the value of p-HER2/HER2, p-Akt/Akt, and restrain Akt activation of HER2and Akt.Conclusion:1. Although the ICa had testosterone mimetic properties in animals,.there is no evidence in vitro that it can promote the proliferation of androgen-dependent LNCaP cellsRather, it can inhibit LNCaP cells to some extent.There are still a lot of investigations to be done as to evaluate whether ICa can facilitate the progression of prostate cancer.2. ICa’s inhibition of LNCaP’s proliferation may have relationship with the decrease in AR protein and the suppression of nuclear translocation, thereby suppressing the activation of AR pathway as well as the target gene (PSA).3. One possible way that ICa inhibits LNCaP’s proliferation is that it may inhibit the activation of HER2-PI3K-Akt signal pathway.4. ICa also has some effects in preventing the antrogen-dependent prostate cancer’s transformation into the antrogen-independent ones.