CXCL12 stimulated sphere formation in vitro and CXCR4+, CXCR7+, and CXCR4+/CXCR7+ cells generate tumors in vivo.

(A) CXCL12 concentration-response assessment indicated that CXCL12 promoted in vitro sphere formation of L0 cells (0.3, 1, 3, 10, 30 nM, P<0.05). CCX733 (100 nM) suppressed CXCL12-regulated (10 nM) sphere formation while AMD3100 (1 µM) had no effect. All conditions contained 0.1% DMSO. ***P<0.001. (B) Representative sections from tumors derived from L0 sub-populations. The various sub-populations indicated in the figures were implanted intracranially into NSG mice. Shown are representative sections subjected to anti-human Nestin immunohistochemistry. Note that all sub-populations are capable of forming tumors in vivo.