Expression of apolipoprotein <scp>C1</scp> in clear cell renal cell carcinoma: An oncogenic gene and a prognostic marker

This study aimed to explore whether APOC1 expression has a function in the biological behavior of clear cell renal cell carcinoma (ccRCC) cells and its possible mechanism. Bioinformatics analysis of data TCGA and OnComine was conducted to explore the expression pattern and prognostic value of APOC1, as well as the relationship between APOC1 expression and clinical indicators. Loss‐ and gain‐ of APOC1 function assays were carried out to assess the biological functions of APOC1. Western blotting was applied to detect protein expression. We revealed that APOC1 was upregulated in ccRCC tissues. APOC1 expression was related to gender, grade, pathologic‐T, pathologic‐stage, and pathologic‐M in patients with ccRCC. Meanwhile, Kaplan–Meier analysis evidenced that the high APOC1 expression indicated unfavorable outcomes of ccRCC. Functional experiments in vitro revealed that upregulation of APOC1 in UT33A cells promoted cell proliferation, invasion, and migration, while downregulation of APOC1 in 786‐O cells had the opposite effect. Furthermore, epithelial mesenchymal transition (EMT) was activated in cells with upregulated APOC1 but inhibited in cells with down‐regulated APOC1. Collectively, our data suggested that APOC1 was overexpressed in ccRCC cells and promoted the malignant biological behaviors and EMT of ccRCC cells.