Comparison of the low-density-lipoprotein receptor activity in human epithelioid gastric carcinoma cell lines and in human normal epithelioid cells

In this experiment, the authors compared the LDLR activity in two human epithelioid gastric carcinoma cell lines (SGC-7901, NKM-45) and two human normal epithelioid cells (amniotic cell line, gastric mucosal cells derived from tissue culture) with the methods of saturation analysis. It was found that the uptake and degradation of 125I-LDL in carcinoma cell line (SGC-7901 and NKM-45) was obviously higher than that in normal cells. The maximum binding of LDL for the four different cell types were 412.02 (SGC-7901), 384.43 (NKM-45), 291.07 (gastric mucosal cell), and 291.42 μg/g cell protein (amniotic cell) respectively, which indicated that the LDLR level was increased in carcinoma cells. The results also showed that the equilibrium dissociation constant (Kd) value in carcinoma cells were similar to that in normal cells, demonstrating the LDLR affinity and specificity was similar in both carcinoma and normal cells