The difference of the adhesion molecule system between blastocyst implantation and cancer invasion

方法：用输卵管冲洗法从ICR雌性过排卵小鼠和交配小鼠中收集4细胞期胚胎。胚胎孵育至囊胚膨大期。根据卵裂球活检位置将受试者分为以下亚组：A组；绕180°方向为B组；C组，距内细胞团（ICM）约90°方向；ICM附近。很少有卵裂球用“狭缝”法活检。采用抗α5β3、抗α6β4整合素和抗α5β1整合素抗体对卵裂球进行免疫组织化学染色。活检后将囊胚置于培养皿中培养72小时。测定囊胚扩张面积，并比较α5β3/α6β4整合素阳性与阴性的差异。结果α5β3整合素和α6β4整合素在A、B组均有表达，c组均未见α5β3整合素表达。α5β3/α6β4整合素阳性囊胚扩张面积大于阴性囊胚。由此可见，α5β3和α6β4整合素在卵裂球上的表达与囊胚扩散活性密切相关。

Methods. 4-cell stage embryos were collected from superovulated and mated ICR female mice with oviduct flushing method. Embryos were incubated until expanded blastocyst stage. Subjects were classified into subgroups according to the position of blastomere biopsy as following, Group A; around the 180° direction, Group B; around the 90° direction from the inner cell mass (ICM), Group C; near ICM. Few blastomeres were biopsied with the "slit" method. These blastomeres were immunohistochemically stained using anti-α5β3, anti-α6β4 integrin and anti-α5β1 integrin antibody. Moreover, these blastocysts were incubated on culture dish for 72 hours after biopsy. The spreading areas of these blastocysts were measured, and were compared between α5β3/α6β4 integrin positive and negative one. Results Expression of α5β3 integrin and α6β4 integrin was seen in Group A and B, but was not in Group C. Expression of α5β3 integrin was not observed in any groups. The spreading area of α5β3/α6β4 integrin positive blastocyst is larger than that of negative one.Conclusions. From these results, we conclude that expression of α5β3 and α6β4 integrin on biopsied blastomeres is closely associated with blastocyst spreading activity.