Expression of TPX2 in kidney renal clear cell carcinoma and its clinical significance / 国际肿瘤学杂志

ABSTRACT

Objective:To analyze the expression of targeting protein for Xklp2 (TPX2) in kidney renal clear cell carcinoma (KIRC) and its clinical significance.Methods:The postoperative tissue samples of 54 patients with KIRC admitted to the Department of Urology, the First Affiliated Hospital of Bengbu Medical College from July 2017 to June 2019 were collected. Immunohistochemistry was used to detect the protein expression of TPX2 in renal carcinoma and paracancerous tissues. The difference of TPX2 mRNA expression between KIRC tissues and normal tissues was analyzed by using the TIMER database, which verified the immunohistochemical results. The UALCAN database and the Kaplan-Meier plotter database were used to analyze the relationship between TPX2 mRNA expression and clinical stage, molecular subtypes, lymph node metastasis, and prognosis of patients with KIRC. The protein interaction network was constructed by STRING database to obtain TPX2-related proteins, and the genes corresponding to the related proteins were enriched for the KEGG pathway. The relationship between TPX2 expression and immune cell infiltration and the immune checkpoint was studied by using the TIMER database.Results:Immunohistochemical results showed that the positive expression rate of TPX2 protein was 48.15% (26/54) in cancer tissues, which was higher than that in paracancerous tissues (20.37%, 11/54) ( χ2=9.25, P=0.002). The results of bioinformatics analysis showed that TPX2 mRNA expression was significantly up-regulated in KIRC [cancer tissue 1.89 (1.49, 2.42), normal tissue 0.35 (0.24, 0.57), U=2 297.00, P<0.001]. The expression of TPX2 mRNA was related to the clinical stage ( χ2=34.36, P<0.001), molecular subtypes ( χ2=30.15, P<0.001), and lymph node metastasis status ( χ2=27.21, P<0.001) of KIRC patients. The 5-year survival rate (53.80%) in patients with high TPX2 expression was lower than that in patients with low TPX2 expression (74.40%, χ2=18.87, P<0.001). STRING database protein interaction network construction obtained 20 TPX2-related proteins, and the genes corresponding to the related proteins were enriched in the cell cycle. The expression of TPX2 was positively correlated with B cells ( r=0.30, P<0.001), CD8 + T cells ( r=0.23, P<0.001), CD4 + T cells ( r=0.18, P<0.001), macrophages ( r=0.20, P<0.001), neutrophils ( r=0.31, P<0.001), dendritic cells ( r=0.39, P<0.001) infiltration and most of its biomarkers (all P<0.05). It was positively correlated with immune checkpoint PD-1 ( r=0.31, P<0.001) and CTLA-4 ( r=0.27, P<0.001), but not correlated with PD-L1 ( r=0.07, P=0.146) . Conclusion:TPX2 is highly expressed in KIRC and is closely associated with poor prognosis. It is expected to be a new therapeutic target for KIRC.