Preliminary study of expression of caspase mRNA and apoptosis in squamous cell carcinoma and basal cell carcinoma

Background: Although many recent reports have suggested an important role of caspase in apoptosis and tumor, little is known about the role of caspase in cutaneous carcinoma. Object: The purpose of this study was to investigate the expressions of caspase-1, 3 and 8, which have been expected to play an important role in the apoptosis, in the normal human skin, squamous cell carcinoma(SCC) and basal cell carcinoma(BCC). Methods: Fresh tissues from 2 normal adults, patients of 6 SCC, and 2 BCC were investigated for the expression of caspase-1, 3, and 8. using RT-PCR technique and in situ apoptotic cells using TUNEL method. Results: Caspase-1 was expressed in one case of normal skin(50%), 2 cases of BCC(100%), 4 cases of 6 SCC(66.7%). Caspase-3 was expressed in the all cases of normal skin, SCC, and BCC. Caspase-3 expression significantly decreased in the order of normal skin, BCC, and SCC. All cancer cases expressed caspase-8 but two normal skin did not express it. Apoptotic cells were shown in several undifferenciated SCC cells and only BCC cells that suffered cystic degeneration. Conclusion: SCC showed decrease of caspase-3 expression comparing BCC or normal tissue but rather increase of caspase-8 expression comparing the normal tissue. In our study, SCC resulted in decrease of apoptosis. And quantitative RT-PCR and more collection of the BCC cases were needed for further definite suggestion.