Self-renewal of MM stem cells in primary host mice, as measured by their ability to transfer MM to a naive secondary host.

A NOD SCID mouse was injected with aggressive myeloma cells from patient 1. When this primary host developed end stage disease at day 79, it was killed and the BM harvested. The BMC were then injected into a second naive NOD SCID recipient (secondary host) to determine whether or not MM stem cells had been regenerated while resident in the primary host BM. The frequency of clonotypic cells in the secondary recipient was determined using the cellular limiting dilution assay. 1000 to 1 BMC from the secondary host were deposited in a 3-fold series into PCR tubes for direct lysis and RT-PCR. The BMC had intact mRNA as measured by the amplification of histone transcripts in separate aliquots of 1 to 1000 cells.