Tumorigenicity and intracisternal A-particle expression of hybrids between murine myeloma and lymphocytes

Hybrids of BALB/c lymphocytes and a murine myeloma, a tumor that expresses intracisternal A-particles, were obtained with polyethylene glycol as the fusogen. The karyotype, tumorigenicity, and A-particle expression of the hybrid clones were assessed. All the hybrid clones analyzed were tumorigenic and expressed intracisternal A-particles even when they were the result of a fusion event between two lymphocytes and one myeloma cell in which no loss of chromosomes was detected. The tumors that developed following inoculation of hybrid cells into BALB/c mice (1 x 10(6) cells/mouse) were karyotypically identical to the inoculated cells. It appears that the two myeloma cell phenotypic traits analyzed (tumorigenicity and A-particle expression) are dominant.