Relationship Between Anti-silencing Function Histone Chaperone 1B（ASF1B）and Clinical Prognosis,proliferation And Invasion Of Pancreatic Cancer

Objective: To investigate the expression of antisilencing histone function 1B（ASF1B）in tumor and its clinical role in pancreatic cancer.To elucidate the differential expression of ASF1 B in human pancreatic cell lines and its effect on proliferation of pancreatic cancer SW1990 cells.Methods: Firstly,the expression differences of ASF1 B in 33 tumors and normal tissues were analyzed in GEPIA and TCGA databases.In TCGA,GEPIA,GEO,TCGA,GEPIA,GEO and KEGG databases: The survival information of each TCGA sample in 190 CASES of PAAD was extracted and the following indicators were selected: Overall survival（OS）,age,TNM stage and grade grade were used to study the relationship between ASF1 B expression and survival prognosis of patients with various cancers.KEGG database: Survival information of each TCGA sample in 190 CASES of PAAD was extracted,and the following indicators were selected: overall survival（OS）,age（AGE）,TNM stage,grade grade,etc.,to study the relationship between ASF1 B expression and survival prognosis of patients with various cancers.Kaplan-meier method and log-rank test were used to conduct Cox univariate and multivariate survival analysis for PAAD（P< 0.05）,and then R software package "Surv Miner" and "Survival" were used to draw the survival curve.Cox analysis was conducted using R package "Survival" and "forestplot" to determine the correlation between ASF1 B and survival time.FDR method was used to adjust p value,FDR truncation value <0.05.R packages "GGpubr" and "Limma" are used for clinicopathological correlation analysis,forest mapping,etc.Through KEGG and GSEA enrichment analysis,ASF1 B may be involved in the regulation of signaling pathways,so as to predict the way and path of its influence on tumor genesis and development.ASF1 B expression was detected by q RT-PCR in cultured pancreatic cell lines.Asf1b-sh1 and ASF1B-SH2 were transfected with pancreatic cancer SW19900 cell line.The transfected blank plasmid was used as the negative control group,and the cells without intervention were used as the normal control group,and the stably transfected ASF1 B knockdown cell line was obtained.The expression of ASF1 B and its effect on the proliferation and migration of SW1990 cells were detected by QRT-PCR assay,cell proliferation-toxicity assay and scratch assay.Results: 1.In TCGA database analysis of pan-cancer,ASF1 B expression was increased in 24 tumors including BLCA,BRCA,PAAD,etc.ASF1 B was expressed in both tumors and matched normal tissues,and the median expression in matched normal tissues was lower than that in tumors.2.Further survival analysis showed that the higher the level of ASF1 B,the less ideal the overall survival（OS）and prognostic effect of PAAD patients were,and the difference was statistically significant.In PAAD patients,the level of ASF1 B in TNM stage Ⅳ（2.45）was higher than that in STAGE Ⅰ（2.30）（P<0.05）.In pancreatic cancer tumors,the higher grade of grade Ⅰ : 2.18,grade Ⅲ : 2.62,the worse the degree of differentiation,the higher level of ASF1 B.In univariate and multivariate COX analysis,only ASF1 B was used as a risk factor for prognosis（P< 0.05）.3.GSEA enrichment analysis of SIX highly correlated pathways of ASF1 B in PAAD and their main regulatory functions are as follows:KEGG＿BASE＿EXCISION＿REPAIR is involved in base repair in cell cycle,KEGG＿CELL＿CYCLE is involved in regulating cell cycle,KEGG＿PRIMARY＿BILE＿ACID＿BIOSYNTHESIS is involved in regulating bile acid synthesis,KEGG＿NEUROACTIVE＿LIGAND＿RECEPTOR＿INTERACTION is involved in the regulation of neuroactive ligand receptor interactions,KEGG＿PROTEASOME is involved in the regulation of proteasome,KEGG＿CARDIAC＿MUSCLE＿CONTRACTION participates in the regulation of cardiac muscle contraction,among which KEGG＿BASE＿EXCISION＿REPAIR and KEGG＿CELL＿CYCLE are the most effective,both of which participate in the process of malignant tumor progression..4.The expression of ASF1 B was negatively correlated with that of HSA-Mir-543,R=-0.17,P=0.022.5.Compared with HPNE（1.001±0.032）cell group,ASC-1（2.799 ± 0.019,P<0.01）,BXPC-3（1.363 ± 0.031,P< 0.001）,SW1990（5.554±0.021,P< 0.01）and PANC-1（2.553 ± 0.032,P< 0.01）cells significantly increased ASF1 B m RNA expression.Knockdown of ASF1 B inhibited the proliferation of PANCREATIC cancer SW1990 cells: F（Normal control）=11.48,P<0.05;F（Negative control）=136.5,P<0.0001;F（ASF1B-SH1）=110.7,P<0.0001;F（ASF1B-SH2）=139.7,P<0.0001.Knockdown of ASF1 B inhibited the migration of PANCREATIC cancer SW1990 cells: the difference was statistically significant（F=70.02,P<0.0001）.Compared with the NC group（80.23±2.375）%,the scratch healing rate of normal control group was（84.15±41.35）%,P=0.9987,P>0.05.The scratch healing rate of ASF1B-SH1 group was（50.45±3.22）% and that of ASF1B-SH2 group was（30.58±1.246）%,both of which were significantly decreased（P<0.0001）.Conclusion: 1.ASF1B’expression is high in many tumors and is an important regulatory factor in the pathogenesis of tumors.2.ASF1 B was significantly correlated with overall survival,TNM stage and grade grade in patients with pancreatic cancer.If the expression level is high,the prognosis and the differentiation degree of malignant tumors is bad.ASF1 B was an independent prognostic factor for clinical survival analysis of patients with pancreatic cancer.3.The expression of ASF1 B was higher in pancreatic cancer tissues and cells,but lower in normal pancreatic tissues and normal pancreatic epithelial cells;Reduced expression of ASF1 B can inhibit the proliferation and migration of pancreatic cancer,which has certain significance in the diagnosis and treatment,therapeutic effect and prognosis of pancreatic cancer.