Figure 3.

BV173 cells express the functional CXCL12 receptor, CXCR4 and migrate toward conditioned medium from MSC. (A) FACS plot of CXCR4 expression in BV173 cells, peripheral blood CML, and CD34⁺ CML cells. (B) Detection of CXCL12 in concentrated supernatant from MSC by immunoblot. MSC were cultured in 75 cm² flasks until confluent. After 24 h culture in low-serum media, supernatants were harvested and concentrated by ultrafiltration. 1: MSC supernatant; 2: BV173 cell supernatant; 3: rCXCL12 50 ng; 4: rCXCL12 10 ng. (C) Migration of BV173 cells toward supernatant collected from MSC culture or toward rCXCL12 in a transwell system. 5x10⁴ BV173 cells were added to the upper chamber of each well in a total volume of 150 mL DMEM 0.5% FBS. Undiluted or diluted supernatants from MSC were added in the lower chamber of the transwell. Cells that had migrated into the lower chamber after 3 h were collected and quantified using a hemocytometer. As a control, the chemotactic activity of rCXCL12 at different concentrations was tested. CM= supernatant from MSC cultures.