VentX Induces Human Hematopoietic Stem Cells To Undergo Erythroid Differentiation And A Preliminary Study On VentX In Tumor Stem Cells' Differentiation

The mammalian homolog of the Xenopus xvent gene named VentX, as a new-found regulatory hematopoietic gene, has critical roles in regulating hemopoietic stem cell proliferation and differentiation. It is also involved in mesodermal patterning, cellular senescence, proliferation, differentiation, and inflammation.GATA-2, a member of the GATA-motif-binding family, plays key roles in hematopoietic development, functions by occupying GATA-binding sites of target genes. Our previous work had demonstrated that GATA-2 can bind with two cis-regulatory elements of VentX promoter. In this study, overexpression vectors and shRNA lentivirus of VentX and GATA-2 were used to transfect CD34+ cells isolated from human bone marrow samples. West blotting, cell proliferation assay and benzidine staining assay were conducted to detect the expression levels of VentX and GATA-2, the impacts to CD34+ cells proliferation and erythropoiesis seperately. The results showed that overexpression of GATA-2 or VentX can inhibit CD34+ cells proliferation and upregulate the expression levels of erythroid-specific factors including ?-, and ?-globin, induce erythroid differentiation of CD34+ cells.Tumor stem cells (TSCs) refer to a subset of tumor cells that has the ability to self-renew and generate the diverse cells that comprise the tumor. They are thought to be crucial for tumorigenesis. The TSCs hypothesis brings a new complete perspective to pathogenesis and progression of cancer as well as a hope for cancer targeting therapy and radical treatment. Because the field of TSC research is in infancy, how the TSCs maintain the potentiality of self-renewal, and the factors related to multi-directional differentiation, unlimited proliferation still remain unclear. In light of TSCs shares important properties with normal tissue stem cells and the regulation of VentX in hemopoietic stem cell differentiation, a preliminary study on VentX in TSCs' differentiation was explored. Serum-free suspension culture was used to enrich TSCs and VentX was overexpressed in BT549 cells, looking for the relationships between overexpression of VentX and proportion of TSCs, and the influence on expression of stem cell marker ALDH1, important factors involved in stem cell differentiation like Nanog, Oct4, TGF-?. Results showed that the expression level of VentX went up with the proportion of TSCs increasing. Overexpression of VentX has the same effects to expression of ALDH1, Nanog, Oct4 and TGF-p, with serum-free suspension culture and these two treatments can both upregulate the expression of ALDH1 in BT549 cells.