Fhit expression is absent or peduced in a subset of primary head and neck cancer

Background: The inactivation of the FHIT gene at 3p14.2 by various mechanis ms might be of importance in head and neck squamous cell carcinoma (HNSCC). Most reports are based on DNA and RNA findings of intragenic deletions and abnormal transcripts. Material and Methods: To study the protein expressio n of this putative tumour suppressor gene, we analysed 48 HNSCCs by immunoh istochemistry using a polyclonal antibody (ZR44). The results were compared with mutation analysis clinical data and loss of heterozygosity (LOH) data at 3p14.2. Results: Complete absence of Fhit expression was detected in 8 out of 48 of tumours (17%) and 3 tumours (6%) showed heterogenous staining The overall frequency of LOH for microsatellite D3S1234 was 64% and 5/7 of Fhit negative tumours exhibited LOH. Conclusion: Our findings provide furth er evidence that FHIT is inactivated in a subtype of HNSCC; however; the in cidence of lack of Fhit expression compared to the high frequency of LOH on chromosome 3p supports the notion of additional tumour suppressor genes at 3p14.