The Effect Of TGF-β1 To The Stem Cells Of Prostate Cancer Cell Line DU145

Background:Prostate cancer (PCa) is the most common malignant tumor in elderly male. scope, its incidence rate incidence rate has been high in the world. In all malignant tumor of male, its incidence rate only after lung cancer, the death rate is sixth. In our country, because of the improvement of living standards, changes in diet and increase of the elderly population, the incidence of prostate cancer is also showed a rising trend year by year.prostate cancer is the second cause of death for male cancer in the western countries. The five years survival rate of localized prostate cancer is up to 100%, but only 31% for advanced prostate cancer. For the early patients without metastases with prostate cancer, most of which can be received very good treatment by radical prostatectomy. At present, for advanced prostate cancer, the main treatment is androgem-deprivation therapy(ADT). but the patients who accept the ADT early sensitive, the majority will be evolution for Castration-Resistant Prostate Cancer(CRPC) in The median survival, eventually lead to difficult to cure. The survival time of patients with PRCP rarely more than eighteen months, so to clarify formation mechanism and effective treatment of CRPC is a very challenging project.The current study shows that the formation of CRPC might related to cancer stem cells exist in prostate cancer.Many scholars believe that there are two kinds of cells in tumor tissue, namely CSC and terminal differentiation of tumor cells.tumor cell of mature terminal differentiation also known as non-tumorigenic cells, accounted for the vast majority of total tumor cells, but the limited ability of proliferation, plays an important role in maintaining the tumor volume and so on, in vitro experiments are hard to become new tumor. The fundamental reason of recurrence and metastasis of tumor is CSC in the presence of tumor tissue. CSC through the activation of anti-apoptotic pathways, increase of membrane transport protein, enhance DNA repair and other means to evade the killing effect on tumor cells by chemotherapy and radiotherapy, leaving a hidden danger for the recurrence and metastasis of tumor.after the anti-tumor treatment, CSC can differentiate into non-proliferation tumor cells and form new tumors.Transforming growth factorβ1(TGF-β1) belongs to a group of the TGF-βsuperfamily which regulation of cell growth and differentiation, it is a kind of multifunctional cytokine, play an important role in the process of invasion and metastasis of tumor.TGF-β is involved in the self-renewal and differentiation of embryonic stem cell, also play an important role in the process of differentiation of adult stem cells.It plays an irreplaceable role in the self-renewal and differentiation of small intestine stem cells, hair follicle stem cells, mesenchymal stem cells and neural stem cells. TGF-β1 signaling pathway is participate in the important process of epithelial-mesenchymal transition (EMT), and the process of EMT was positively correlated with the degree of tumor malignant.Objective:Research the TGF-β1 effects on prostate cancer cell line DU145 by in vitro experimental. Using flow cytometry to detect the tumor stem cell phenotype of CD133 expressing rate in prostate cancer DU145 cell line after intervene by TGF-β1 of different concentrations. Study the effect of DU145 in proliferation, invasion, migration after TGF-β1 of different concentrations roled by MTT method. And detected the expression of related protein and gene by Western-Blot(WB) and qRT-PCR, to explore its related mechanism.Methods:1. Using MTT method to detect the changes of proliferation of prostate cancer DU145 cell line before and after the intervention of different TGF-β1 concentrations.2. Research the affect of migration and invasion ability of prostate carcinoma cell line DU145 with different concentrations of TGF-β1 by Transwell.3. Using flow cytometry to detect the tumor stem cell phenotype of CD133 expressing rate of prostate cancer DU145 cell line after intervene by different concentrations of TGF-β1.4. Using qRT-PCR detected the expression of related gene of prostate cancer DU145 cell line with different concentrations of TGF-β1.5. Detected the expression of related protein of prostate cancer DU145 cell line with different concentrations of TGF-β1 by Western-Blot.Results:1. The MTT showed that TGF-β1 can inhibit the proliferation of prostate cancer cell line DU145. The proliferation capacity of DU145 declined when TGF-β1 is increased from 2.5ng/ml to lOng/ml2. TGF-β1 can promote the migration and invasive ability of prostate cancer DU145 cells line, and increased with the concentration of TGF-β1, the migration and invasion ability of prostate cancer DU145 cells line was enhanced, presented positive correlation.3. the flow cytometry detection displayed that TGF-β1 can promote the expression of tumor stem cell surface marker GD133, and the expression rate of CD133 was increased with the concentration of TGF-β1.4. the qRT-PCR results indicated that TGF-β1 can inhibit expression of the gene and β-catenin when the its concentration at 2.5ng/ml, but the effect not increased with concentration. At the same time, the TGF-β1 promoting the expression of the gene of Sox2 and ABCG2 and the effect increased with concentration.5. Western-blot results showed that TGF-β1 inhibits the expression of protein β-catenin when the its concentration at 2.5ng/ml and the difference had been statistical significance (P<0.05), and with the increase of TGF-β1 concentration, the inhibition not increased. TGF-β1 can promote the expression of ABCG2 and Sox2 protein and the difference had statistical significance (P<0.05) when the concentration of 2.5ng/mlConclusion:In prostate cancer cell line DU145, TGF-β1 can inhibit the proliferation of tumour cells and weaken the function of Wnt/β-catenin pathway, and promote the expression of ABCG2 and Sox2 meanwhile.At the same time, TGF-β1 can promote the expression of cancer stem cell surface marker CD133 and enhanced the migration and invasion ability. Anyway, TGF-β1 may through some signal pathway in tumor cells, the proliferation ability is abate, but enhanced the ability of stem cells, leading to tumor is difficult to cure, easy to relapse and metastasis.