Expression Of LEFTY1 And Screening Of Differentially Expressed Genes Between Left And Right Colon Cancer

Objective :1.To compare the expression of LEFTY1 between left and right colon cancer and to explore its clinical significance.2.To further investigate the differences in gene expression between left and right colon cancer,and to provide more molecular genetic basis for genotyping,pathogenesis,individualized treatment and survival prognosis of left and right colon cancer.Methods:1.Retrospective analysis of clinical and pathological data of locally advanced left and right colon cancer patients admitted to The Third Affiliated Hospital of Kunming Medical University(Yunnan Cancer Hospital)and treated with surgery from January 2015 to December 2017,and the expression of LEFTY1 in left and right colon cancer tissues was detected by applying immunohistochemistry.2.By downloading and analyzing relevant datasets from GEO database to obtain differentially expressed genes between left and right colon cancer tissues,and performing gene GO,KEGG enrichment analysis and protein interaction network analysis.Results:1.There are significant differences between left and right colon cancer in terms of tissue differentiation,tumor size,incidence of anemia and clinical manifestations.In terms of the degree of tissue differentiation,tumor size and incidence of anemia,there are significantly more patients with right colon cancer,tumor size ≥5 cm and anemia than those with left colon cancer,and the difference is statistically significant(P < 0.05);In terms of clinical manifestations,patients with right colon cancer mainly showed symptoms such as abdominal pain,ventosity,and diarrhea,while patients with left colon cancer mainly showed bleeding symptoms such as blood in stool,bloody stool and black stool.The high expression rate of LEFTY1 in left colon cancer(34.6%)is significantly higher than that in right colon cancer(22.2%),but the difference is not statistically significant(P > 0.05).The expression of LEFTY1 correlated with tumor size in left and right colon cancer,and the proportion of patients with tumor size ≥5 cm is significantly higher in colon cancer with low expression of LEFTY1 than in those with high expression of LEFTY1,and it is more significant in right colon cancer,and the difference is statistically significant(P < 0.05).The mean survival time of patients with left colon cancer is significantly higher than that of right colon cancer(64.6 months vs 60.1 months),and the difference is statistically significant(P < 0.05);the cumulative survival rate of patients with low expression of LEFTY1 in left and right colon cancer is slightly lower than that of patients with high expression(61.2 months vs 63.7 months),but the difference is not statistically significant(P > 0.05);Total bile acid is the most important factor affecting independent risk factors for prognosis of patients with left colon cancer;stage M1,stage IV,vascular infiltration,CA-199 and CA-242 are independent risk factors for prognosis of patients with right colon cancer.2.Bioinformatics analysis is performed to identify DEGs that may be involved in the carcinogenesis or progression of left and right colon cancer.12 DEGs(HOXC6,PRAC1,SNW1,SPTLC2,AREL1,ZBTB25,ETNK1,PTPRD,NTRK3,ATXN3,SMCHD1,RSRC1)and 6 key genes(SYF2,SNRPA1,PRPF19,DHX8,SNW1,SNRNP200),provide more ideas for the follow-up study on the occurrence and development of left and right colon cancer.Conclusion:1.There are differences between left and right colon cancer in terms of tissue differentiation,tumor size,incidence of anemia,and clinical manifestations.While there is no significant difference in the expression of LEFTY1 between left and right colon cancer,but its low expression was associated with tumor size.The proportion of patients with primary tumor ≥5cm in colon cancer with low LEFTY1 expression was significantly higher than that in patients with high LEFTY1 expression,and it was more significant in right colon cancer.2.The total bile acids are independent risk factors affecting the prognosis of patients with left colon cancer;stage M1,stage IV,vascular infiltration,CA-199 and CA-242 were independent risk factors affecting the prognosis of patients with right colon cancer.3.There are significant differences in the expression of genes between left and right colon cancer.These differentially expressed genes are involved in several signaling pathways,including the neuronutrient signaling pathway,calcium signaling pathway,sphingoid signaling pathway and Notch signaling pathway,and are involved in several metabolic processes including sphingoid metabolism,glycerol phospholipid metabolism and central carbon metabolism of cancer.The role of these genes and their related signaling pathways in the occurrence and development of left and right colon cancer remains to be further verified.