| Objective: Prostate Cancer(PCa)is one of the most common epithelial malignancies in elderly men worldwide,and it is also the fifth leading cause of death from cancer in men.Currently,prostate specific antigen(PSA)is a diagnostic indicator of prostate cancer,but false positives and overdiagnosis have appeared.Among them,prostate cancer patients are more likely to develop into castration-resistant prostate cancer after androgen deprivation treatment,and their prognosis is poor.Therefore,it is necessary to construct a robust prognostic model of prostate cancer risk to distinguish between high and low risk patients.Iron is one of the trace elements closely related to human health.It not only participates in oxygen transport,cell respiration,immune function,CO metabolism and DNA synthesis.At the same time,iron ions also mediate the occurrence of iron death,which can promote cell death.Play an important role in treatment.This study uses a two-sample Mendelian randomization method to explore the causal relationship between iron and prostate cancer,observe the changes in iron ions during iron death,establish a prognostic model based on iron death-related genes,and verify the key gene pairs in the prognostic model The impact of prostate cancer.Methods: This study explores the effect of iron death on prostate cancer step by step,which consists of three parts.The first part is to explore the causal relationship between iron and prostate cancer and the change of iron ion concentration in iron death.First,extract the single nucleoside closely related to iron status(P<5×10-8)from the genome-wide association study of iron status Acid polymorphisms(SNPs)are used as instrumental variables,and the corresponding genetic sites are further selected in the PRACTICAL database,and the current Mendelian randomization method,which is more effective in causal inference,is used to explore the causal relationship between iron and prostate cancer.At the same time,CCK8 was used to observe the inhibition of cell proliferation when iron death occurred,the morphological changes of intracellular mitochondria were observed by transmission electron microscope,and the change of intracellular iron ion concentration was monitored by iron ion colorimetry.The second part is to construct a prognostic model of prostate cancer patients based on iron death-related genes.In determining the causal relationship between iron and prostate cancer,the second part of the study downloads the transcriptome expression data of prostate cancer patients and the corresponding clinical data from the TCGA database,and obtains the gene data related to iron death from the Ferr Db database,which is related to iron death Take the intersection of genes based on gene and TCGA expression matrix to calculate differentially expressed genes.Subsequently,LASSO and COX regression were used to construct a multi-gene prognostic model in the TCGA cohort.Based on the prognostic model,prostate cancer patients are divided into high and low risk groups.Through the high-risk and low-risk groups,genetic analysis of differences between the groups was performed.Finally,GO analysis,KEGG analysis and ss GSEA analysis were performed according to the risk differentially expressed genes.The third part is the effect of AKR1C1 overexpression on the function of prostate cancer cells.The second part is to screen out the differential genes of AKR1C1 with prognostic value through the construction of the second part of the prognosis model.The third part is to detect the expression of AKR1C1 in PC3,DU145 and LNCap by q PCR According to the situation,select the best target cells for plasmid transfection.AKR1C1 was overexpressed in prostate cancer cells by plasmid transfection.Transwell migration test was used to detect the migration ability of AKR1C1 overexpressed PC3 cells and the cell proliferation ability was observed by CCK8.Results: In the first part of the study,11 SNPs strongly correlated with iron status were obtained from the data of genome-wide association analysis as instrumental variables.In the traditional group,there was a causal relationship between iron status and prostate cancer(OR: 0.879,95% CI: 0.813-0.950,P=0.001).At the same time,in the free group,there was a causal relationship between serum iron and prostate cancer(OR: 0.910,95% CI: 0.833-0.995,P=0.039),and the other three iron biomarkers(transferrin saturation,ferritin And transferrin)and prostate cancer have no significant causal relationship(P>0.05).At the same time,the iron death inducer Erastin can not only inhibit the survival of PC3,LNCap and Du145 and induce their death,but the viability of prostate cancer cells decreases with the increase of erastin concentration,and the mitochondrial morphology of prostate cancer cells induced by erastin also changes.Moreover,after Erastin induces iron death in cells,the intracellular iron ion level increases with the increase of erastin concentration.In the second part of the study,it was found that 24 iron death-related genes were differentially expressed between prostate cancer samples and the normal group.18 intersection genes with both expression differences and prognostic value were screened and regressed through LASSO and COX A prognostic model based on7 iron death-related genes(NOX1,VDAC2,ALOX12,BAP1,MIOX,AKR1C1,BNIP3)was constructed.Among the 7 iron death-related genes,AKR1C1 is compared with adjacent tissues in prostate cancer.Tissue low expression.At the same time,patients are divided into high-risk and low-risk groups through a prognostic model.Compared with the low-risk group,the overall survival rate of the high-risk group was significantly lower(P<0.001).In addition,the AUC values within 1 year,2 years,and 3 years are calculated by the time-dependent ROC curve to be 0.988,0.936,0.861.The third part of the study found that the expression of AKR1C1 in PC3 and LNCap cells was much lower than that in DU145,but the expression of AKR1C1 was similar in PC3 and LNCap.Due to the fast growth of PC3 cells,PC3 was selected as the target cell for AKR1C1 overexpression transfection.After AKR1C1 was expressed in PC3 cells,it inhibited the migration of PC3 cells.Conclusions: Based on the two-sample Mendelian randomization method,SNP is used as an instrumental variable to predict the causal relationship between iron and the risk of prostate cancer.Iron ions play an important role in inducing iron death in prostate cancer and can be adjusted to a certain extent by regulating iron ions.Prevent,control and treat prostate cancer.At the same time,7 differential genes with prognostic value were screened.The prognostic model constructed based on these 7 iron death-related genes can effectively distinguish high and low risk prostate cancer patients,in order to avoid excessive treatment of prostate cancer patients.Provide a reference.AKR1C1 plays an important role in the migration and proliferation of prostate cancer.On the one hand,it provides a basis for more in-depth research on the role of AKR1C1 in iron death of prostate cancer.On the other hand,it also confirms the role of prostate cancer prognostic models. |
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