Expression of carbonic anhydrases I/II and the correlation to clinical aspects of oral squamous cell carcinoma analyzed using tissue microarray

Background: Carbonic anhydrases (CA), a family of metalloenzymes, play an important role in catalyzing the equilibration of carbon dioxide (CO2) and carbonic acid (H2CO3). The role of CAs in tumorigenesis is controversial, especially regarding the expression of CA isoenzymes between various tumor types. This study explores the correlation between the expressions of CA I and CA II and the characteristic features of oral cancer. Methods: We immunohistochemically examined the expressions of CA I and CA II in 279 cases of oral squamous cell carcinoma (OSCC) using tissue microarrays. Additionally, the oral cancer cell line SCC-9 was used to confirm the relationship between CA I and CA II expression and cell growth. Results: We found a significant correlation between positive CA I and CA II stains and OSCC for more advanced clinical stage (P=0.014 or 0.012) and larger tumor size (P=0.008 or 0.038), but not for positive lymph node metastasis, distal metastasis, and recurrence. In vitro analysis also showed that treatment with a CA inhibitor, acetazolamide, inhibited the growth of SCC-9 cells. Conclusion: We conclude that expressions of CA I and CA II in OSCC samples can be used to predict local tumor growth in OSCC patients.