No abstract

Epidermal growth factor (EGF) receptor is expressed selectively by human melanoma cells which show the presence of an extra copy of chromosome 7. None of the cells of benign pigmented lesions (nevi) or radial growth phase (nonmetastatic) primary melanoma expressed EGF receptor and none of these cells showed an extra copy of chromosome 7. The results indicate that a single extra dose of a gene (for EGF receptor) may provide a selective advantage to cells in the late stages of tumorigenesis.

No abstract

We previously reported the non-random occurrence of monosomy 22 in rhabdoid or atypical teratoid tumors of the brain in three young children. We now present cytogenetic and molecular studies of an additional rhabdoid tumor with the karyotype 46,XX,-9,-22,+i(1q),+der(22)t(9;22)(p13;q11)/45,XX,-9,-10,- 22,+i(1q),+der(22)t(9;22)(p13;q11). These studies further demonstrate the involvement of chromosome 22, and they begin to define the critical region containing a gene or genes involved in the development or progression of rhabdoid tumors of the brain.

Cytogenetic studies of a rhabdomyosarcoma of mixed embryonal and alveolar histology in an 11-month-old male revealed a single structural abnormality, t(1;13)(p36;q14). This abnormality may define a subset of patients with a variant of the t(2;13)(q35;q14) translocation frequently seen in alveolar rhabdomyosarcoma.