Molecular Mechanism Of SIRPB1 On Promoting Prostate Cancer Cells Proliferation And Migration

Background: With the development of economy,the incidence of cancer has gradually grown in China.Cancer is an important public health problem affecting people's quality of life and life expectancy,seriously affected social and economic development.Prostate cancer is the most common male malignancy and the second leading cause of cancer death after lung cancer in the United States.In recent years,with the aging of our population and the change of dietary habits,the incidence of prostate cancer is increasing in china.Prostate cancer is the third cause of urinary and genital malignancies in male and prostate cancer has ranked first one in some developed region.Prostate cancer has become malignant neoplasm that seriously affects men's health.The current initial treatment of metastatic prostate cancer remains androgen deprivation therapy(ADT),either through surgical castration or through medical castration.The disease inevitably progresses to castration-resistant prostate cancer(CRPC),which is associated with a poor prognosis and poses considerable therapeutic challenges.So it is particularly important to find a new target of androgen independence.We explored the molecular mechanisms of SIRPB1 through cellular function study in prostate cancerMethods: 1.To analyze of SIRPB1 expression in prostate cancer using c Bioportal database.2.To detect expression of SIRPB1 in prostate cancer cell line using RT-PCR and Western Blot.3.To knockdown SIRPB1 expression in prostate cancer cells 4.To establish stable overexpressing of SIRPB1 prostate cancer cell line 5.To explore cell proliferation in knockdown or overexpression SIRPB1 cells using clone formation assay.6.To explore cell motility in knockdown SIRPB1 cells using wound healing assay.7.To explore cell migration in knockdown SIRPB1 or overexpression SIRPB1 cells using Transwell assay.8.To detect cell apoptosis in knockdown SIRPB1 or overexpression SIRPB1 cells using Flow cytometry 9.To detect cell cycle arrest in knockdown SIRPB1 cells using Flow cytometric.10.To determine tumor formation of SIRPB1 in prostate cancer cells in vivo by a subcutaneous xenograft model.11.To analyze potential signals of pathways regulated by SIRPB1 in prostate cancer using RNA-seq method.12.To identify important molecules involved in cell proliferation regulated by SIRPB1Results: SIRPB1 gene amplification in 39% of prostate cancer tissues.SIRPB1 is widely expressed by prostate cancer cell lines.The knockdown effect and overexpression of SIRPB1 was verified by Western Blot.Knockdown of SIRPB1 in PC3 cells inhibited cell clone formation in number and size of colonies.Knockdown of SIRPB1 in PC3 cells inhibited cell motility using wound healing assay.Knockdown of SIRPB1 in PC3 cells promoted cell number of Annexin V+cells and induced cell cycle arrest at G1 phase.Overexpression of SIRPB1 in C4-2 cells promoted cell colony formation at the number and size of colonies.Overexpression of SIRPB1 in C4-2 cells promoted cell migration using trasnwell assay.Overexpression of SIRPB1 in C4-2 cells increased the rate of tumor take in mice.Knockdown of SIRPB1 down regulated phosphorylation of AKT at Th308 and Ser473.Overexpression of SIRPB1 unregulated phosphorylation of AKT at Thr308 and Ser473.AKT inhibitor MK2206 inhibited cell proliferation induced by SIRPB1 in overexpression SIRPB1 C4-2 cells.Conclusion: SIRPB1 was widely expressed by prostate cancer cell lines;Knockdown of SIRPB1 by RNAi in PC3 prostate cancer cells resulted in profound suppression of cell growth in a colony formation assay and cell mobility in wound-healing and Transwell assays.Knockdown of SIRPB1 induced cell cycle arrest during the G1 phase and an enhancement of apoptosis.Conversely,overexpression of SIPRB1 in C4-2 prostate cancer cells significantly induced cell migration,invasion,colony formation.SIRPB1 promoted cell proliferation through AKT phosphorylation.Furthermore,overexpression of SIRPB1 enhanced C4-2 xenograft tumor takes rate in nude mice.These results suggest that SIRPB1 should be an oncogene in prostate cancer and could be a biomarker for patients at risk of developing aggressive prostate cancer.