Molecular analysis of the IL-6 receptor in human multiple myeloma, an IL-6-related disease

A PCR-SSCP approach was used to search for mutations in IL-6 receptor genes in 9 human plasma cell lines (HMCL) and in tumor plasma cells from 19 patients with fulminating multiple myeloma, an IL-6-related disease. Whereas no mutation was found in the cytokine receptor homologous (CRH) domain of IL-6R alpha, DNA and RNA polymorphisms in the gp130 CRH domain was detected in tumoral samples as well as in blood samples from healthy donors. Finally, mutations in the gp130 critical cytoplasmic domain were found in one HMCL and in tumor plasma cells of one patient. Only the mutated allele was expressed in the HMCL.