Relationship between expression of L-selectin, integrin αL and integrin β2 and multiple-organ metastasis of breast cancer in TA2 mice

Abstract

Objective:To investigate the effect of the L-selectin,integrin αL and integrin β2 expressions on the multiple -organ metastasis of breast cancer of TA2 mice.Methods:The pathologic character of spontaneous breast cancer with multiple-organ metastasis (high metastasis,Group A) and without distant metastasis (low metastasis,Group B) were observed by macroscopy and HE staining sections.The level of the L-selectin,integrin αL and integrin β2 expressions in Group A,Group B and the metastatic tumors of Group A were detected using the immunohistochemical method.The level of the mRNA of L-selectin,integrin aL and integrin β2 relative expressions in the prmary tumors of Group A and Group B were detected by Real-time PCR method.Results:Hemorrhage and necrosis were visibly seen in all the primary tumors of the Group A which were poorly differentiated or undifferentiated.Pulmonary,hepatic and splenic metastases,and angiogenetic mimicry were observed in these tumors.The average positive cell percentage of integrin αL and L-selectin in primary tumors of Group A and Group B were 24.81% vs.10.47% and 39.81% vs.16.75%,respectively.The expressions of the proteins were significantly higher in Group A than in Group B (Z=-2.31,-2.14,respectively;P0.05),while there was no significant difference in the expression of integrin (32 between the two groups.In Group A,the average levels of L-selectin expression were 39.81%,39.07%,62.09% and 55.51% in the primary tumors,and the pulmonary,hepatic and splenic metastatic tumors,respectively,among which the average expression of L-selectin was significantly higher in liver metastatic tumor than in primary tumor (Z=-2.24,P=0.025),while there was no markedly difference in the expression of integrin αL and integrin β2 between the primary and metastastic tumor.The levels of L-selectin and integrin αL mRNA relative expression were significantly higher in the primary tumros of Group A than in those of Group B (Z=-3.32,-3.47;P 0.01).Conclusion:L-selectin, integrin αL and integrin β2 could be expressed by spontaneous breast cancer cells of TA2 mice and the expression of L-selectin might be related to liver metastasis.