ABSTRACT
OBJECTIVE: Intratumoral hypoxia (IH) occurs during cellular proliferation of malignant tumors. This phenomenon is characterized by a decrease in oxygen levels in the neoplastic microenvironment. Throughout this condition, the proteins HIF-1α, NOTCH1, ADAM12, and HB-EGF can be activated, triggering signaling pathways associated with tumor invasiveness through invadopodia formation. This study aimed to evaluate the immunostaining of HIF-1α, NOTCH1, ADAM12, and HBEGF in 19 cases of mucoepidermoid carcinoma (MEC) and 10 samples of salivary glands (control group). STUDY DESIGN: The immunoperoxidase technique was employed to detect the proteins of interest. The Student t test was used to compare immunoexpression between MEC samples and the control group. RESULTS: Protein immunostaining was statistically significantly higher in MEC samples than in the control group (P < .01), and the proteins were especially overexpressed in epidermoid cells of MEC. CONCLUSIONS: We suggest that there is an association between the NOTCH1 signaling pathway activated by IH and the biologic behavior of MEC.