Expressions of matrix metalloproteinase 7 and secretory leukocyte protease inhibitor in papillary thyroid carcinoma and their significances / 中国现代普通外科进展

ABSTRACT

Objective:To investigate the expressions of matrix metalloproteinase 7(MMP7)and secretory leukocyte protease inhibitor(SLPI)in papillary thyroid carcinoma(PTC)and their signifi-cances.Methods:Based on the gene expression data of thyroid cancer in the tumor Genome Atlas(TCGA)database,a total of 567 samples were collected,including 509 cancer tissues and 58 normal tissues.The gene matrix data were extracted and sorted out.Two groups of differentially expressed genes were screened by using the R language edger package,and the potential key genes were screened by the mcode plug-in in Cytoscape.Select a key gene and mine closely related genes through the UALCAN database.Immunohistochemical SABC method was used to detect the ex-pressions of MMP7 and SLPI proteins in PTC tissues and their paracancerous tissues collected from 69 patients in Binzhou People's Hospital Affiliated to Shandong First Medical University from January 2020 to June 2021,and the association of expression levels of MMP7 and SLPI with the clinico-pathological factors of PTC patients was also analyzed.Results:Based on the data of TCGA database,1471 genes were obtained,of which 1000 were up-regulated and 471 were down-regu-lated.Through the mcode plug-in in Cytoscape,20 key genes were screened(MMP7,CCL18,CYR61,SPECC1,CRABP2,PLXNA3,KRT17,TMEM59L,RETN,SRF,ITGB4,PPL,PLEKHN1,RMI2,LCN6,SPX,NRIP1,ARHGEF28,SLC39A14,SNCA).Through the UALCAN database,the correlation between MMP7 and SLPI was retrieved(Pearson correlation coefficient was 0.5,P＜0.05).The results of immunohistochemistry showed that the positive expression rates of MMP7 and SLPI proteins in PTC tissues were significantly higher than those in paracancerous tissues[82.6％(57/69)vs 29.0％(20/69),71.0％(49/69)vs 15.9％(11/69)],and the differences were statistically significant(x2 val-ues were 40.222 and 42.579,both P＜0.01).The expressions of MMP7 and SLPI in PTC tissues were correlated with TNM stage,differentiation,extramembranous invasion and lymph node metastasis(all P＜0.05).There was a positive correlation between MMP7 and SLPI proteins expressions in PTC(r=0.381,P=0.001).Conclusions:The interaction between MMP7 and SLPI proteins can be in-volved in the development and progression of PTC.