Effect of all-trans retinoic acid on growth of xenograft tumor and its metastasis in nude mice

Objective To study the effect of all-trans retinoic acid on growth of xenog raft tumor and its metastasis in nude mice. Methods Human gastric cancer BGC-823 and MKN-45 cells were inoculated into spleen subcapsule of nude mice, respectively. The nude mice were subsequent ly administered with all-trans retinoic acid every other day. Food consumin g and body weight of nude mice were measured weekly. Six weeks later, the n ude mice were killed. Xenograft tumors in spleen and metastatic tumors in l iver were pathologically examined. Microvessel density in the tumors was de tected immunohistochemically, and serum carcinoembryonic antigen was measur ed by radioimmunoassay. Results After the nude mice were fed with all-trans retinoic acid, the grow th of splenic tumor and its liver metastasis were inhibited and the metasta tic rates decreased by 50% ( BGC-823) and 33.3% (MKN-45), respectively. The microvessel density in splenic and hepatic tumors reduced by 28.58% and 35 .47% (BGC-823), 19.45% and 14.52% (MKN-45), respectively. The concentration of carcinoembryonic antigen decreased by 50.24% (BGC-823) and 48.10% (MKN- 45). Conclusion All-trans retinoic acid may effectively inhibit the growth of xe nograft tumor in spleen and its metastasis to liver in nude mice, which can be corroborated by the decrease of carcinoembryonic antigen and microvesse l density.