Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, Higashiosaka, Osaka, Japan.
Exp Cell Res. 2013 Feb 1;319(3):105-12. doi: 10.1016/j.yexcr.2012.09.014. Epub 2012 Oct 3.
Lysophosphatidic acid (LPA) mediates a variety of cellular responses with atleast six G protein-coupled transmembrane receptors (LPA receptor-1 (LPA(1)-LPA(6))). The interaction between LPA receptors and other cellular molecules on the biological function is not fully understood. Recently, we have reported that LPA(1) suppressed and LPA(3) stimulated cell migration of pancreatic cancer cells. In the present study, to evaluate the function of LPA(2) on motile and invasive activities of pancreatic cancer cells, we generated Lpar2 knockdown (HPD-sh2) cells from hamster pancreatic cancer cells and measured their cell migration ability. In cell motility and invasive assays with an uncoated Cell Culture Insert, HPD-sh2 cells showed significantly lower intrinsic activity than control (HPD-GFP) cells. Since K-ras mutations were frequently detected in pancreatic cancer, we next investigated whether oncogenic K-ras is involved in cell migration induced by LPA(2) using K-ras knockdown (HPD-K2) cells. The cell motile ability of HPD-K2 cells was significantly lower than that of control cells. To confirm LPA(2) increases cell migration activity, cells were pretreated with dioctylglycerol pyrophosphate (DGPP) which is the antagonist of LPA(1)/LPA(3). The cell motile and invasive abilities of DGPP -treated HPD-GFP cells were markedly higher than those of untreated cells, but DGPP did not stimulate cell migration of HPD-K2 cells. These results suggest that cell migration activity of pancreatic cancer cells stimulated by LPA(2) may be enhanced by oncogenic K-ras.
溶血磷脂酸（LPA）通过至少六种 G 蛋白偶联跨膜受体（LPA 受体-1（LPA1-LPA6））介导多种细胞反应。LPA 受体与其他细胞分子的相互作用在生物学功能上尚未完全理解。最近，我们报道了 LPA1 抑制和 LPA3 刺激胰腺癌细胞的迁移。在本研究中，为了评估 LPA2 对胰腺癌细胞迁移和侵袭活性的功能，我们从小鼠胰腺癌细胞中生成了 Lpar2 敲低（HPD-sh2）细胞，并测量了它们的细胞迁移能力。在无涂层细胞培养插入物的细胞迁移和侵袭测定中，HPD-sh2 细胞的内在活性明显低于对照（HPD-GFP）细胞。由于胰腺癌中经常检测到 K-ras 突变，我们接下来使用 K-ras 敲低（HPD-K2）细胞研究致癌 K-ras 是否参与 LPA2 诱导的细胞迁移。HPD-K2 细胞的细胞迁移能力明显低于对照细胞。为了确认 LPA2 增加细胞迁移活性，用二油基甘油焦磷酸（DGPP）预处理细胞，DGPP 是 LPA1/LPA3 的拮抗剂。DGPP 处理的 HPD-GFP 细胞的细胞迁移和侵袭能力明显高于未经处理的细胞，但 DGPP 不能刺激 HPD-K2 细胞的细胞迁移。这些结果表明，LPA2 刺激的胰腺癌细胞的迁移活性可能被致癌 K-ras 增强。
