Frequent amplification of the bcl-1 locus in head and neck squamous cell carcinomas

The bcl-1 locus on chromosome 11 at band q13 has been shown to be rearranged in some chronic B lymphoid malignancies with the t(11;14)(q13;q32). Chromosome 11 abnormalities also occur in squamous cell carcinomas including tumors from the head and neck region. In this investigation, we analysed the arrangement, copy number and expression of this locus in 23 fresh head and neck cancers and six established head and neck squamous cell carcinoma cell lines. Bcl-1 was found to be amplified two- to 10-fold in eight fresh tumors and two cell lines, UM-SCC-8 and UM-SCC-22A. Moreover, amplification was more frequently observed in poorly differentiated fresh tumors. None of the fresh tumors or cell lines showed rearrangement of bcl-1. In addition, these tumors and cell lines did not contain amplification of the c-myc or Ha-ras oncogenes.