The Mechanism Of Antimony Promoting Prostate Cancer Progression By Up-regulating The Expression Of CtBP2

ObjectiveTo identify the influence of the low dose antimony exposure in promoting prostate cancer progression and to preliminarily explore the mechanism of the interaction. MethodsThe sublethal dose antimony exposure of PC3 cells was detected by MTT assay. And in the dose, the role of the low dose antimony exposure in cell proliferation of PC3 cells was detected by MTT assay. And the assay confirmed the most significant dose of influencing cell proliferation. PC3 cells were exposed using the dose of antimony. And the wound scratch assay, the transwell assay and Annexin V assay were used to assess the cell migration, invasion and apoptosis. The transcriptome sequencing assay was used to explore the abnormal gene expression of the low dose antimony exposed to PC3 cells. According to the results of the transcriptome sequencing assay, the role of the low dose antimony exposure in CtBP2 and downstream proteins mRNA and protein expression was assessed by RT-qPCR and Western Blot assay. The MRE was searched by inquiring the upstream DNA sequence of CtBP2 promoter. The plasmids of MRE were compounded and transfected into HEK293 T cells. And in order to confirm the relationship between the low dose antimony and MRE, the luciferase activity was detected by the luciferase reporter assay system. The model of PC3 cells transplanted into subcutaneous tissues of nude mice exposed to the low dose antimony was established. The role of the low dose antimony exposed to the tumor growth was confirmed. The change of nude mice weight and tumor volume was recorded. And the data was used to draw the growth curve. The expression of CtBP2 and downstream proteins in tumor tissue was detected by Western Blot assay. ResultsThe low dose antimony could promote cell proliferation. And the most significant dose of promoting proliferation was 8 uM(P<0.05). When 8 uM antimony exposed, it could promote cell migration and invasion significantly(P<0.05). But it could not influence cell apoptosis. The result of the transcriptome sequencing assay demonstrated the low dose antimony exposure lead to abnormal gene expression, including the high expression of CtBP2(P<0.05). The result of RT-qPCR assay testified the low dose antimony could increase the CtBP2 mRNA expression. And Western Blot assay testified the low dose antimony could increase CtBP2 and downstream proteins expression in PC3 cells(P<0.05). After the MRE was found in the upstream DNA sequence of CtBP2 promoter, it verified that MRE can regulate CtBP2 expression. After the plasmids of MRE were compounded, the luciferase reporter assay system testified that there is an interaction between the low dose antimony and MRE. And it could increase CtBP2 expression. After the model of PC3 cells transplanted into subcutaneous tissues of nude mice exposed to antimony was established, the nude mice tumor volume were(1344.9±882.8) mm3 and(2612.4±777.5) mm3 in the control group and 10mg/kg/d group. The low dose antimony exposure could promote tumor growth(P<0.05). Similarly, the result of Western Blot testified the low dose antimony exposure increase CtBP2 and downstream proteins expression in nude mice tumor(P<0.05). ConclusionThe low dose antimony exposure influence the biological behavior of the prostate cells significantly. The mechanism of the low dose antimony promoting prostate cancer progression is that the interaction between the low dose antimony and MRE increase CtBP2 expression and regulate CtBP2-c-Myc pathway.