RESUMEN
OBJECTIVE： To study the anti－ metastatic action of equal/unequal－ fork－ peptide of YIGSR.METHODS： To observe the influence of drugs on metastasis of melanoma B16 to lung in mice.RESULTS： The metastatic rate of lung in 46 mice of control and experimental groups was 100％ ,21 days after inoculating melanoma B16 cells via caudal vein.Injection of YIGSR in combination with tumor cells could reduce the number of metastatic nodules in a dose－ dependent manner.The numbers of metastatic nodules in 100μ g～ 200μ g equal fork peptide group and same dosage unequal fork peptide group were significantly different from that in control group(P<0.05;P<0.01 respectively).50μ g equal fork peptide group was different from control group.The synthetic peptide could not decrease the weight of the lung with metastatic lesions.CONCLUSION： YIGSR derivants have effective antimetastatic actions.Its mechanism may related to the inhibiting effect on formation of cancer cell emboli,which retain in microvessels of remote target organs,and multiplicate and penetrate blood vessels to form micrometastatic lesions.