Background: Hypoxia is present in many solid tumors and is a prognostic factor for poor tumorigenesis. Here, we investigated whether carcinoembryonic antigen (CEA) plays a role in the hypoxic microenvironment of breast cancer.
Methods: We researched the expression of CEA in breast tumor tissues and the corresponding paracancerous tissues. Furthermore, western blotting was used to detect the expression levels of CEA in breast cancer cells cultured under hypoxia or normoxia. The expression levels of CEA, hypoxia-inducible factor-1α (HIF-1α) and carbonic anhydrase IX (CA-IX) in tumor tissues were detected by immunohistochemical staining. In addition, the correlations between CEA and clinical parameters and prognosis of breast cancer patients were analyzed by statistical analysis.
Results: We found that CEA mRNA expression of tissues in breast cancer patients was significantly increased compared to the corresponding paracancerous tissues. Furthermore, the expression levels of CEA in breast cancer cells cultured under hypoxic conditions were elevated compared with those cultured under normoxic conditions. Immunohistochemical staining demonstrated that the expression of CEA in tumor tissues was increased with HIF-1α, and the area of CA-IX expression could be seen with CEA distribution. In addition, the clinical parameter analysis found that serum CEA was significantly associated with malignant clinical features. We also found that elevated CEA expression was related to poor prognosis in breast cancer patients.
Conclusions: CEA expression was elevated in the breast cancer hypoxic microenvironment, and the data suggested a rationale for the use of CEA in breast cancer diagnosis, assessment, and prognosis.