BRAK/CXCL14 expression in oral carcinoma cells completely suppresses tumor cell xenografts in SCID mouse.

SCID mice are a model of human severe combined immunodeficiency disease and are deficient in B cell function in addition to T cell function. Tumors from other species are easily transplanted into SCID mice and will grow without being rejected. We previously reported that the chemokine BRAK/CXCL14 is expressed in normal cells but its expression is down regulated in an in vitro cancer progression model, suggesting that it has the potential for antitumor activity. Here we report that the growth of BRAK/CXCL14 expression vector-transfected oral cancer cells was completely (100%) suppressed in SCID mouse xenografts even though mock-vector introduced control tumor cells grew well with 100% of animals developing tumors. In addition, suppression of xenografts was much faster and the rate was much higher in SCID mice than in T cell function-deficient nude mice. These data indicate the possibility that BRAK expression inhibits tumor cell establishment by regulating interactions between tumor stem cells and NK cells and/or suppressing formation of tumor microvessels.