Objective: To investigate the expression of Notch1 in human tongue squamous carcinoma (TSCC) and precancerous lesion, and to explore the potential relation between Notch1 and epidermal growth factor receptor (EGFR).
Methods: The expression of Notch1 and EGFR was detected in human TSCC (n = 41), tongue leukoplakia (LP) (n = 39) and normal tongue mucosa (n = 7) by immunohistochemistry.
Results: In normal tongue mucosa and LP, the positive staining of Notch1 was mainly distributed in stratum corneum, partially in stratum granulosum and stratum spinosum, but not in stratum basale, while the positive staining of EGFR was mainly distributed in stratum basale, rarely in stratum spinosum, but not in stratum granulosum and stratum corneum. In TSCC, Notch1 expression was mainly distributed in locations of squamous metaplasia, but not in peripheral cells of carcinomas, while EGFR expression was detected mainly in peripheral cells of carcinomas, but not in locations of squamous metaplasia.
Conclusion: Notch1 promotes the differentiation of epithelial cells in tongue mucosa and acts as a tumor suppressor in TSCC. EGFR may act as a negative regulator of Notch1 expression in epithelium of tongue mucosa and TSCC, for maintaining cell proliferation and promoting the tumorigenesis and progression of TSCC.