Expression of <i>CXCR4</i> is upregulated after serial transplantation.

<p>(A) RT-PCR of <i>MUC5AC</i>, <i>CXCR4</i>, <i>CXCR7</i>, and <i>CXCL12</i> in a GC cell line HSC-60 and its subline 60As6. (B) Immunocytochemistry for MUC5AC (left panel, green) and CXCR4 (right panel, green) in HSC-60 and 60As6 cells, respectively. Nuclei were counterstained with DAPI (blue). Scale bars represent 100μm. (C) Flow cytometry analysis of cell-surface CXCR4 in 60As6 cells. The inner panels represent CXCR4⁺ small cells (I), CXCR4^- small cells (II) and CXCR4^- large cells (III) (Ci). Each cell population was separated by FACS at its respective purity (Ci-Civ). Immunopositive cells for MUC5AC were observed in only the CXCR4^- large cell fraction (Civ, lower panel, green). Scale bars represent 50μm. (D) Representative images after culturing CXCR4^- small and large cells for 3 days. Scale bars represent 50μm.