COX4I2 is a novel biomarker of blood supply in adrenal tumors

BACKGROUND: Previous study has been reported that COX4I2 expression level demonstrated a positive correlation with microvessel density in pheochromocytomas (PCC) samples, suggesting that the expression of COX4I2 maybe related to blood supply level in other adrenal tumors as well. The aim of this study is to clarify the correlation of COX4I2 expression and blood supply in adrenal tumors. METHODS: A total of 84 patients were recruited, among which 46 was diagnosed as adrenocortical adenoma (ACA) and 38 was diagnosed as PCC. Contrast-enhanced CT values were used to evaluate the blood supply levels in those patients. The expression of mRNA was examined by quantitative real-time polymerase chain reaction (qPCR) and protein was detected by immunohistochemistry (IHC). RESULTS: The COX4I2 expression level in PCC group is significantly higher than that in ACA group (P<0.01). The expression of angiogenesis-related genes EPAS1, VEGFA and KDR mRNA in PCC group is higher than that of ACA group (P<0.05). Correlation analysis shows COX4I2 expression level is correlated with CT values (P<0.001), intraoperative blood loss (P<0.05) and operation time (P<0.05), and the expression of COX4I2 mRNA is correlated with EPAS1, VEGFA and KDR mRNA (P<0.01). CONCLUSIONS: The results displayed a distinct expression level of COX4I2 between ACA and PCC, suggesting that COX4I2 is a novel biomarker of blood supply in adrenal tumors. This research also opens the possibility for further research on COX4I2 as a novel target for anti-tumor angiogenesis.