Overexpression of BMP-2/4,-5 and BMPR-IA associated with malignancy of oral epithelium

The aim of the present study was to determine the relationships between bon e morphogenetic proteins (BMPs), BMP receptor type IA and carcinogenesis of oral epithelium. A retrospective study was performed on material obtained from oral mucosa, including nine cases of normal mucosa (NB), eight cases o f nonspecific chronic inflammation (NCI), seven cases of hyperkeratosis (HK ), five cases of squamous cell papilloma (SCP), 29 cases of squamous cell c arcinoma (SCC) with various grades of differentiation and 10 cases of epith elium adjacent to carcinoma (EAC). Six cases of NE from hard palate (NHP) w ere chosen as a control group. The benign groups consisted of NCI, KK and S CP. The antibodies against BMP-2/4, -5, receptor BMPR-IA and purified bovin e BMP (bBMP-McAb) were utilised using an immunocytochemical method. The res ults demonstrated that the immunostaining of BMP-2/4, BMP-5, BMPR-IA and bB MP-McAb was weak and not consistent in normal and benign groups. The immuno reactivity level was independent of the clinical and pathological grading o f SCC. All cases of SCC showed positive staining for BMP-2/4, BMP-5, BMPR-I A and bBMP-McAb except for three cases and one case of SCC which negatively stained for BMP 2/4 and BMP-5, respectively. The staining intensity and pr oportion of the positively stained cells were markedly increased in SCC whe n compared with that of the normal and benign groups except for EAC. The me tastatic carcinoma cells in lymph nodes were strongly and positively staine d for BMP-2/4 and BMP-5 when compared with the primary lesions. Our results indicate that there was an overexpression of BMP-2/4, BMP-5, bBMP-McAb and BMPR-IA in the high-risk premalignant and malignant lesions of oral epithe lium. Our findings suggest that BMP-2/4 and BMP-5 but not BMPR-IA might be involved in the metastasis of oral carcinoma cells. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.