Among the cells stocks, one distinguishes the hematopoïetic stocks cells (HSC), which are in fact the cells stocks of blood. They are used to produce blood cells at the time of the bone-marrow grafts. Unfortunately these cells are rare and little by taking away of it is recovered. Moreover, it was a long time difficult to make them duplicate ex vivo. Indeed, the first methods, using growth promoters, transform them and they are not any more stocks cells.
First step : a team discovered in Montreal that the HoxB4 gene, already implied in the growth of the embryos, allows when it is inserted in a HSC to duplicate it in great number, and that in vivo. Blow, one can produce many cells in their leaving their quality of stocks cells. But this method is not exploitable médicalement : indeed, the introduction of gene produces a genetic change of the cells, which is not desirable.
Fortunately, other former work had shown that the proteins of the Hox type have the capacity to spontaneously penetrate in the cells. From where the idea of a team of Inserm (unit 567) which succeeded in October 2003 transferring in the HSC in vivo from the HoxB4 proteins, without placing of genetic material. There are thus the advantages of the first method, without modification of the DNA.
This discovery, which simplifies the grafts, will certainly also find applications in other therapeutic sectors.