Laminin-5对前列腺癌细胞侵袭能力的影响

Laminin-5 cells stimulate the migration of prostate cancer cells

背景与目的:目前对前列腺原位癌进展到浸润性癌的机制知之甚少。在前列腺癌中,间质细胞能分泌一定的因子,促进肿瘤细胞的生长和浸润,但是正常的上皮分泌细胞/原位癌细胞和间质细胞被完整的基底细胞层所隔离。本研究探讨前列腺基底上皮细胞分泌的Laminin-5因子对前列腺原位癌细胞侵袭能力的影响。方法:以BPH-1细胞作为前列腺原位癌的体外模型,研究细胞在基底上皮细胞条件培养基(PEC-CM)作用下的粘附、侵袭能力和细胞极性改变情况,并应用免疫沉淀反应和Western blot等技术分析PEC-CM的主要成分。结果:PEC-CM含有粘着蛋白等因子,能促进细胞粘附、极化、侵袭和Akt磷酸化。LY294002和Wortmannin能够部分抑制PEC-CM所激发的细胞侵袭作用,Laminin-5正是PEC-CM中刺激BPH-1细胞侵袭的有效蛋白成分,两者抑制效果比较差异有显著性(P<0.01)。用抗体耗竭PEC-CM内的Laminin-5也能有效降低BPH-1细胞的侵袭能力(P<0.01)。结论:由前列腺基底细胞分泌的Laminin-5通过PI3K依赖的传导通路,对前列腺癌细胞侵袭能力有促进作用,提示基底细胞在前列腺原位癌向浸润性癌的演变过程中可能具有重要作用。

Background and purpose： The genetic and epidemic events that mediate the progression from in-situ to invasive prostate carcinoma are poorly understood. Stoma factors may facilitate the growth and invasion of tumor cells that have lost regulatory mechanisms. However, in situ carcinoma cells are separaled from the stoma by a continuous layer of basal epithelial cells. During progression to invasive carcinoma, the basal cell layer becomes disrupted and tumor cells adhere to the basement membrane. This paper discussed the role of Laminin-5 secreted by basal epithelial cells that participated in the invasion of in situ prostate cancer cells. Methods： BPH-1 cells were used as an in vitro model of pre-invasive prostate cancer fells in order to investigate the migration-promoting activity of secreted factors from basal epithelial cells. Adhesion proteins and chemotactic factors that stimulate adhesion, planar polarization, migration were studied by techniques such as immunofluorescent analysis, immunoprecipitation and Western blot. Results： The results showed that the conditioned medium of basal epithelial cells （PEC-CM） contained adhesion proteins and chemotactic factors that stimulated adhesion, planar polarization, migration, and could phosphorylate Akt. LY294002 and Wortmannin partially inhibited PEC-CM-triggered migration（P 〈 0.01）. Laminin-5 was identified as a major migration-stimulating protein for BPH-1 cells in PEC-CM. In addition, antibody-depletion of Laminin-5 from PEC-CM significantly diminished the migration of BPH-1 cells（P 〈 0.01）. Conclusions： Laminin-5 is secreted by basal prostate epithelial cells in vivo and in vitro. Migration of BPH-1 cells stimulated by Laminin-5 might depend on PI3-kinase survival signal pathway, our primary conclusion suggests that basal epithelial cells might play an important role in the process of prostate cancer cells from in situ stage to invasive stage.