Expression of laminin binding protein (37LBP/p40) and tumor angiogenesis in lung cancer

37 kDa层粘连蛋白结合蛋白(37LBP)是67 kDa层粘连蛋白受体的前体蛋白，其表达与癌细胞的生物学侵袭性密切相关。然而，37LBP的详细作用尚不完全清楚。为了直接阐明37LBP在肿瘤细胞中的作用，用反义RNA表达载体建立了37LBP表达显著下调的小鼠肺癌细胞系T11。将5x10@d15@d1细胞皮下接种同系小鼠，T11受体的平均存活时间(77.0()Sy.-.[14.8天]较亲本细胞系P29(34.8[]SY)显著延长。-.[)5.5天)和正义RNA转染体T42(33.4()Sy.-.[)4.2d)，(p&lt；0.001)。免疫组织化学结果显示，T11的微血管密度明显低于P29和T42(p&lt；0.05)。与P29和T42相比，在条件培养液中培养的T11细胞对毛细血管内皮细胞的增殖(p&lt；0.01)和迁移(p&lt；0.05)均有显著的抑制作用。这些结果提示，37LBP在T11中的低表达可能与其低致瘤性有关，这可能部分是由于小鼠肺癌的肿瘤血管生成减少所致。

Expression of the 37-kDa laminin binding protein (37LBP), a precursor protein of the 67-kDa laminin receptor, correlates well with biological aggressiveness of cancer cells. However, the detailed role of 37LBP is not fully understood. To elucidate the role playd by the 37LBP in cancer cells directly, a murine lung cancer cell line T11, in which 37LBP expression was remarkably diminished, was established by an antisense RNA expression vector. When 5x10<@D15@>D1 cells were subcutaneously inoculated into syngenic mice, the mean survival time of T11-recipient (77.0(]SY.+-。[)14.8 days) was significantly prolonged compared with that of both the parental cell line P29 (34.8(]SY.+-。[)5.5 days) and the sense RNA-transfectant T42 (33.4(]SY.+-。[)4.2 days), (p<0.001). Immunohistochemistry of inoculated tumors of the same size demonstrated that microvessel density in T11 was significantly lower than that observed in both P29 and T42 (p<0.05). It was also shown that T11 cells cultured in a conditioned medium exhibited signiflcantly reduced proliferation (p<0.01) and migration (p<0.05) of the capillary endothelial cells compared with P29 and T42. These results suggest that decreased expression of 37LBP in T11 may relate to its low tumorigenicity, and that this may be partly caused by diminished tumor angiogenesis of the murine lung cancer.