Proliferation of LAMA-84 and LAMA-87 cell lines is modulated by autocrine loops involving M-CSF and TGF-beta
Champelovier, P.; Fixe, P.; Valiron, O.; Feige, J.J.; Praloran, V.; Seigneurin, D.
Experimental Hematology 25(9): 958-965
1997
ISSN/ISBN: 0301-472X PMID: 9257809 Document Number: 475043
The erythromegakaryocytic cell line (LAMA-84) and the erythroeosinophilic cell line (LAMA-87) were used to study receptor expression and receptor-mediated response to monocyte/macrophage colony-stimulating factor (M-CSF) and transforming growth factor beta (TGF-beta), two modulators of cell proliferation. As demonstrated by Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR), cfms and M-CSF mRNA were expressed in both cell lines. M-CSF was detected in the supernatant of both cell lines and addition of a neutralizing anti-M-CSF antibody inhibited cell growth. The two LAMA cell lines were found to express TGF-beta-1, -beta-2, and -beta-3 mRNAs and to secrete TGF-beta mostly in latent form. Addition of anti-TGF-beta antibodies to the culture medium increased their proliferation, whereas TGF-beta-1 inhibited cell proliferation by downregulating the c-myc mRNA. These results show that the proliferation of both LAMA cell lines is positively and negatively regulated by autocrine mechanisms, implying the presence of M-CSF and TGF-beta, respectively. They suggest that similar autocrine loops could be involved in the growth regulation of leukemic cells in vivo.