Eight cytogenetically characterized head and neck squamous cell carcinomas (HNSCCs) with CCND1 amplification in the form of a homogeneously staining region (hsr) in 11q13 were studied by COBRA FISH and FISH with specific probes to identify and characterize chromosomal segments added to the derivative chromosomes 11. In 4 of the tumors, it could be recognized that the material added was derived from the long arm of chromosome 3. The rearrangements were interpreted as der(11)hsr(11)(q13)t(3;11)(q21;q13) in 3 cases and as der(11)hsr(11)(q13)t(3;11)(q14;q13) in 1 case. In the other 4 cases, material from chromosomes 1, 16, or 19 was added to the derivative chromosomes 11. By further FISH analysis with 14 YAC clones spanning 3q13-q21 in the 4 tumors with der(11)hsr(11)t(3;11), it could be shown that they had different breakpoints at the molecular level, excluding the possibility that a particular gene was rearranged by the translocations. More surprisingly, gain of the 3q21-q29 segment was found in all 8 tumors with hsr in 11q13 and loss of 3p was seen in 7 of the tumors. These findings strongly indicate a synergistic effect of CCND1 amplification, loss of distal 11q, 3q gain and 3p deletion in HNSCC development and also suggests a mechanistic link between intrachromosomal amplification at 11q13 and recombination with distal 3q.
Copyright 2002 Wiley-Liss, Inc.