Stem cell antigen 2: a new gene involved in the self-renewal of erythroid progenitors

• Published in: Cell proliferation 2008-10, Vol.41 (5), p.726-738
• Main Authors: Bresson-Mazet, C., Gandrillon, O., Gonin-Giraud, S.
• Format: Article
• Language: English
• Subjects: Animals; Biochemistry, Molecular Biology; Cell Differentiation; Cell Differentiation - drug effects; Cell Proliferation; Cell Proliferation - drug effects; Chickens; Down-Regulation; Down-Regulation - drug effects; Erythroid Precursor Cells; Erythroid Precursor Cells - cytology; Erythroid Precursor Cells - drug effects; Erythroid Precursor Cells - metabolism; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Neoplastic - drug effects; Humans; Life Sciences; Membrane Proteins; Membrane Proteins - genetics; Membrane Proteins - metabolism; Molecular biology; Neoplasms; Neoplasms - genetics; Original; Receptors, Transforming Growth Factor beta; Receptors, Transforming Growth Factor beta - metabolism; RNA Interference; Transforming Growth Factor beta; Transforming Growth Factor beta - pharmacology
• ISSN: 0960-7722; 1365-2184
• DOI: 10.1111/j.1365-2184.2008.00554.x

.  Objectives: Stem cell antigen 2 (SCA2), also known as TSA1 and LY6E, is a glycosylphosphatidylinositol‐anchored molecule that belongs to the Ly‐6 family and whose function remains largely unknown. We have previously shown that SCA2 is overexpressed in self‐renewing avian erythroid progenitors (T2ECs) as opposed to differentiating T2ECs. The aim of this study was to define the role of SCA2 in the switch between self‐renewal and differentiation of erythroid progenitors. Materials and methods: We have investigated the cellular processes controlled by SCA2 in T2ECs by RNA interference and overexpression approaches. Moreover, we have used a SAGE Querying and analysis tools developed in our laboratory, to investigate the expression level of SCA2 gene in different human cell types. Results: We demonstrate the regulation of SCA2 expression by TGF‐β, a growth factor essential for self‐renewal of T2ECs. We establish that SCA2 knockdown by RNA interference reduced the proliferation and promoted the differentiation of T2ECs. In contrast, SCA2 overexpression inhibited differentiation of T2ECs only. Furthermore, by using a bioinformatic approach, we found that SCA2 is highly expressed in a variety of human cancer cells. We confirmed this result by quantitative PCR on human colon and kidney tissues. Conclusions: Altogether, these findings imply that SCA2 may function in a dose‐dependent manner to support the self‐renewal state and that its deregulation might contribute to the development of some human cancers.