Expression of basement membrane antigens and matrix metalloproteinases 2 and 9 in cutaneous basal and squamous cell carcinomas.

Background: Basement membrane (BM) antigens and matrix metalloproteinases (MMP) are involved in tumor invasion and metastasis. Basal (BCC) and squamous cell carcinomas (SCC) differ with respect to their biological behavior since the former are only locally aggressive whereas the latter have a metastatic potential.

Materials And Methods: We studied the immunohistochemical expression of several BM antigens and of MMP2 and MMP9, in 13 BCC, 13 SCC, and 8 in situ skin carcinomas.

Results: The expression of most BM antigens was reduced in the tumors in comparison with normal skin. Hemidesmosome- and lamina lucida-associated antigens (plectin, NUT2, alpha 6/CD49f and laminin-5) were more decreased in BCC, whereas collagens type VII and IV were more decreased in SCC as compared with BCC; in BCC and SCC both collagens tended to be decreased on the leading edge of invasive tumor masses. In situ carcinomas showed a slightly diminished expression of alpha 6/CD49f integrin, plectin and NUT2. The expression of both MMP2 and MMP9 was increased in SCC as compared with BCC.

Conclusion: Our findings further upheld the role of BM antigens and MMPs in the process of tumor aggressiveness. The reduced expression of collagen IV, combined with an increased expression of both MMP2 and MMP9 could account for the increased metastatic potential of SCC vs BCC through an increased invasion of the extracellular matrix and the vascular space.