The relative expression level of every sample was than comparable. c MYC expression was also upregulated upon stimulation with NGF in imatinib handled cells in the absence of serum, nonetheless, its expression level was reduce than that in Table two PANTHER analyses of c Kit versus NGF regulated genes that are involved in immune associated function in HMC one cells imatinib untreated cells with serum. To examine whether substantial c MYC expression in untreated cells is because of the activated c Kit kinase and or serum which may possibly contain activation aspect with the c MYC gene, we carried out c MYC distinct qRT PCR within the pre sence of serum with imatinib and or NGF. Imatinib suppressed c MYC expression about 70% even in the presence of serum, suggesting that activated c Kit induces c MYC expression.
However, in the presence of serum, NGF induces c MYC expression 2 fold in excess of in the absence of serum, suggesting that serum and c Kit or TrkA tyrosine kinase synergistically induce c MYC expression. Moreover, 32 genes, like c MYC, EGR1, EGR2, HES1, and KLF2 of 58 genes that were downmo dulated by imatinib and upregulated upon stimulation with NGF are involved in survival and proliferation, sug gesting that NGF TrkA Hygromycin B signaling may take over the sur vival and or mitogenic signal while in the imatinib treated HMC one cells employing these genes. Novel target genes, KLF2, and SMAD7 which were induced by NGF TrkA signaling are involved in anti apoptosis signal in hematopoietic cell program Expression profiling of NGF TrkA induced genes is nicely documented in neuronal cell systems.
Nonetheless, there is certainly no info about profiles of genes induced by NGF TrkA signaling in a hematopoietic cell procedure. We hence compared our upregulated genes to acknowledged NGF targets in neuronal cells. Quite a few genes, such since the not too long ago demonstrated ATF3, KLF10, and v maf muscu loaponeurotic fibrosarcoma oncogene relatives protein now F were identified to be induced in our array. Additionally to the above, we display for that very first time the upregulation of likely novel TrkA target genes this kind of as KLF2, SMAD7, and Homeobox members, HOXB8 and PBX2, on NGF stimulation in HMC one cells. Because it has been proven that an quick early gene products, KLF2 activates SMAD7 expression, we examined the upregulation of KLF2, SMAD7 and EGR1 by RT PCR.
In agreement with array data, KLF2 was upregulated within thirty min just like the EGR1 gene, even so, SMAD7 was upregulated in two h, sting that KLF2 could be the direct target gene of NGF TrkA signaling, but not SMAD7. We next asked irrespective of whether KLF2 and SMAD7 are targets of c Kit signaling. Considering that oncogenic c Kit just isn't completely activated, SCF therapy is capable to induce additional upregulation of c Kit mediated signaling. HMC 1 cells were grown during the absence of serum for 17 h, and had been then sti mulated with SCF. The expression of KLF2, SMAD7 and EGR1 was then examined by RT PCR. All three genes had been upregulated by stimulation with SCF.