Significance of the small subtelomeric area of chromosome 1 (1p36.3) in the progression of malignant melanoma: FISH deletion screening with YAC DNA probes

The short arm of chromosome 1 (1p), especially the subtelomeric region of 1 p36, is a common site for abnormalities in malignant melanoma of the skin. In a recent study nodular melanomas displayed deletions of 1p36 in an augme nted percentage of cases. To evaluate the dimension of these deletions and to study their significance for the progression of malignant melanoma we an alyzed seven melanoma cell lines, 32 primary tumors, and 32 metastatic tumo rs by fluorescence in situ hybridization with the DNA probe D1Z2 in 1p36.3 and eight YAC DNA probes hybridizing to 1p36, 1p32, 1p31, and 1p21. All cel l lines, 91% of the metastatic tumors and 63% of nodular melanomas showed a deletion of 1p36.3. In the YAC hybridization experiments, the most frequen t deletions were found in 1p36 in all cell lines, in 13% of nodular melanom a, and in 44% of metastatic tumors. Deletions in 1p36 were mostly confined to a rather small area near the locus D1Z2. The frequent occurrence of this deletion in melanomas with a high metastatic potential and the abundant ac cumulation of this deletion in metastasis point to genes located on 1p36, w hich might be of significance for the metastatic capability of malignant me lanoma.