Current studies indicate an important function for HOXcontaining genes in normal and neoplastic adult cells. We have shown that selected HOX genes are expressed and play a key role in early hematopoietic stem/progenitor cell (HSC/HPC) differentiation, but HOXB7 is essentially not transcribed during the normal hematopoietic maturation process. On the contrary it has been reported to be expressed in human leukemias and leukemic cell lines of different types; we have also demonstrated a specific link between HOXB7 expression and melanoma cell proliferation. In this study we have transduced HOXB7, via retroviral infection, in HSCs/HPCs stringently purified from normal adult peripheral blood and investigated the effects of its abnormal expression in stage- or lineage-specific assays. HOXB7 constitutive expression induced a proliferative stimulus during the differentiation/maturation of the granulocytic and monocytic lineages, coupled with and possibly due to a delay of differentiation, since a discrete population of blasts was still present after prolonged culture. No differences were found along erythroid and megakaryocytic differentiation/maturation. Interestingly, we have observed a remarkable expansion of the number of putative HSCs and primitive HPCs. as evaluated by long term initiating cells (LTC-IC) and HPP-CFC assays respectively in the HOXB7-transduced cells. In conclusion these studies indicate that HOXB7 overexpression induces increased proliferation and myeloid-resfricted differentiation of HSCs/HPCs.
|Number of pages||1|
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Cancer Research
- Cell Biology