MAGEA11 Cooperates With AR To Regulate The Mechanism Of FSTL1 In The Occurrence And Development Of Prostate Cancer

Prostate cancer is the most common malignancy of male genitourinary system,and it is one of the main causes of cancer death in men in Europe and the United States.The incidence of prostate cancer is up to 46 percent in men over the age of 50 years old,according to an autopsy conducted by a research institute in the United States.The incidence and mortality of prostate cancer vary by region and race,with the highest incidence among black people,followed by Caucasian,and the lowest among Asians.However,in China,with the aging of the population and the change of diet structure,the incidence and mortality of tumors continue to increase,and the incidence of prostate cancer is also increasing year by year,which has become an important factor affecting the health of Chinese men,especially men over 50 years old.The treatment of prostate cancer includes radical surgery,radiotherapy,endocrine therapy,chemotherapy,targeted therapy,immunotherapy and other comprehensive treatment measures.The prognosis of patients with early stage prostate cancer is usually promising,but there are still a considerable number of patients are diagnosed after distant metastasis related symptoms appear,leading to poor prognosis.After 1 to 2 years of androgen deprivation therapy,advanced Prostate Cancer is prone to evolve from Androgen Dependent Prostate Cancer(ADPC)to castration-resistant Prostate Cancer(CRPC),and patients eventually die from extensive metastasis of androgen-insensitive Prostate Cancer cells.Prostate cancer is also one of the most common malignant tumors with bone metastasis.Bone metastasis occurs in 85%of prostate cancer patients,and the 5-year survival rate for orthotopic prostate cancer is 88%,while the 5-year survival rate for patients with bone metastasis is 29%,and the incidence of bone metastasis is about 90%in patients who die of prostate cancer.In castration-resistant prostate cancer,the incidence of bone metastasis was greater than 90%,significantly higher than androgen-dependent prostate cancer.Bone metastasis of prostate cancer can cause a variety of complications,such as pathological fractures,spinal nerve compression symptoms and severe pain,which seriously affect the daily life of patients and significantly shorten the survival period of patients.Therefore,the study on the occurrence and development mechanism of prostate cancer and the mechanism of metastasis and evolution of advanced prostate cancer to castration-resistant prostate cancer can provide a new insight for the treatment of prostate cancer.Melanoma antigen family All(MAGEA11),as a co-regulator of Androgen Receptor(AR),is significantly increased in the mRNA and protein level in castration-resistant prostate cancer,thereby enhancing the transcriptional activity of AR.Interaction between the two plays an important role in the progression of prostate cancer.In the meanwhile,studies found that Follistatin-like protein 1(FSTL1)fuction as a glycoprotein,belong to the extracellular matrix protein family,participate in a variety of biological processes,including cell proliferation,apoptosis,metabolism,differentiation and immune response and endocrine function,and play an important role in human organ development and tumorigenesis.Studies have confirmed that FSTL1 plays an important regulatory role in the occurrence and development of colon cancer,brain glioblastoma,breast cancer,endometrial cancer and ovarian cancer.However,the mechanism of FSTL1 in the occurrence and development of prostate cancer is still unknown.Previous studies have found that FSTL1 gene expression was significantly down-regulated in prostate cancer cells LAPC4 after silencing MAGEA11 with lentivirus shRNA,using Microarray technology.Realtime PCR was used to further confirm that the expression level of FSTL1 mRNA was significantly inhibited when MAGEA11 gene was silenced.The aim of this study was to to explore the role of FSTL1 in the occurrence and development of prostate cancer by detecting the regulation and interaction of MAGEA11 synergistic AR in the expression of FSTL1 in prostate cancer,so as to provide new insights for the diagnosis and treatment of prostate cancer.Part IRegulation of FSTL1 by MAGEA11 and AR in prostate cancer Objective:To investigate the interaction between MAGEA11 and AR and FSTL1 in prostate cancer cells.Materials and methods:Real-time quantitative PCR(qrt-pcr)and Western Blot were used to detect the expression level of FSTL1 in different malignant tumor cell lines and its relationship with MAGEA11.Lentivirus transfection was used to MAGEA11 and AR in human prostate cancer cell line LAPC4,the transfection efficiency was detected by real-time quantitative PCR(qrt-pcr)and Western blot,and the expression of FSTL1 gene after MAGEA11 and AR knockdown was further detected.To detect the effect of different hormones on the expression of FSTL1 in prostate cancer cell line LAPC4.Chromatin Immunoprecipitation(ChIP Assay)was used to detect the interaction between androgen receptor and FSTL1 and the androgen-dependent characteristics.Results:Compared with other malignant tumor cell lines,both MAGEA11 and FSTL1 proteins were highly expressed in prostate cancer cell line LAPC4.After knockdown of MAGEA11 and AR by lentivirus transfection in prostate cancer cells LAPC4,qrt-pcr results showed that the expression of FSTL1 gene was significantly decreased,and the expression of FSTL1 gene was increased in an androgen dependent manner.The expression of FSTL1 protein was increased in an androgen dependent manner and was not affected by progestrone and estrogen.Chromatin Immunoprecipitation found that ndrogen receptor binds to the 10th intron region of FSTL1 gene,and the combination of AR protein and FSTL1 gene shows an increase in androgen dependence and time dependence manner.Conclusion:In prostate cancer cells,the expression of FSTL1 is regulated by MAGEA11 and AR,and the expression of FSTL1 is increased in an androgen-dependent manner.The interaction between AR and FSTL1 increased in androgen dependent and time dependent manner.Part ?The role of FSTL1 in the progression of prostate cancerObjective:To invest the expression of FSTL1 in CWR22 xenograft tumor model of prostate cancer and the relationship between FSTL1 and MAGEA11,and to explore the role of FSTL1 in the progression of prostate cancer.Materials and methods:Real-time quantitative PCR(q-rt-pcr)was used to detect the expressions of FSTL1 and MAGEA11 in tissue samples of CWR22 xenograft tumor model of prostate cancer at different stages.Immunohistochemistry was used to detect the localization of FSTL1 and MAGEA11 proteins in CWR22 xenograft tumor model of prostate cancer,benign prostatic hyperplasia and castration-resistant prostate cancer.Immunofluorescence assay was used to detect the relationship between the nuclear localization of FSTL1 and androgen receptor and androgen in different prostate cancer cells.Results:The expression of FSTL1 mRNA increased during the progression of CWR22 mouse model to castration-resistant prostate cancer,and was positively correlated with the expression of MAGE A11 mRNA.Immunohistochemistry showed that FSTL1 was located in cytoplasm and nucleus of androgen-stimulated CWR22 tumor tissues and tumor tissues on day 2 and day 6 of castration,while FSTL1 was less stained in cytoplasm and mainly in nuclear of castrated resisten CWR22 tumor tissues..In benign prostate epithelial cells,FSTL1 is mainly located in the cytoplasm,while in castration resistant prostate cancer tissues,FSTL1 is mainly located in the nuclear.Conclusion:During the progression of prostate cancer to castration-resistant prostate cancer,the expression of FSTL1 mRNA gradually increased and was positively correlated with the expression of MAGEA11 mRNA,and the increased expression of FSTL1 was related to the nuclear localization of FSTL1.