Brusevold Ingvild J, Tveteraas Ingun H, Aasrum Monica, Ødegård John, Sandnes Dagny L, Christoffersen Thoralf
Department of Pharmacology, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, and Oslo University Hospital, Blindern, P,O, Box 1057, Oslo N-0316, Norway.
BMC Cancer. 2014 Jun 13;14:432. doi: 10.1186/1471-2407-14-432.
Oral squamous cell carcinoma is an aggressive neoplasm with serious morbidity and mortality, which typically spreads through local invasive growth. Lysophosphatidic acid (LPA) is involved in a number of biological processes, and may have a role in cancer cell migration and invasiveness. LPA is present in most tissues and can activate cells through six different LPA receptors (LPAR1-6). Although LPA is predominantly promigratory, some of the receptors may have antimigratory effects in certain cells. The signalling mechanisms of LPA are not fully understood, and in oral carcinoma cells the specific receptors and pathways involved in LPA-stimulated migration are unknown.
The oral carcinoma cell lines E10, SCC-9, and D2 were investigated. Cell migration was studied in a scratch wound assay, and invasion was demonstrated in organotypic three dimensional co-cultures. Protein and mRNA expression of LPA receptors was studied with Western blotting and qRT-PCR. Activation of signalling proteins was examined with Western blotting and isoelectric focusing, and signalling mechanisms were further explored using pharmacological agents and siRNA directed at specific receptors and pathways.
LPA stimulated cell migration in the two oral carcinoma cell lines E10 and SCC-9, but was slightly inhibitory in D2. The receptor expression profile and the effects of specific pharmacological antagonist and agonists indicated that LPA-stimulated cell migration was mediated through LPAR3 in E10 and SCC-9. Furthermore, in both these cell lines, the stimulation by LPA was dependent on PKC activity. However, while LPA induced transactivation of EGFR and the stimulated migration was blocked by EGFR inhibitors in E10 cells, LPA did not induce EGFR transactivation in SCC-9 cells. In D2 cells, LPA induced EGFR transactivation, but this was associated with slowing of a very high inherent migration rate in these cells.
The results demonstrate LPA-stimulated migration in oral carcinoma cells through LPAR3, mediated further by PKC, which acts either in concert with or independently of EGFR transactivation.
口腔鳞状细胞癌是一种侵袭性肿瘤，具有严重的发病率和死亡率，通常通过局部浸润性生长扩散。溶血磷脂酸（LPA）参与多种生物学过程，可能在癌细胞迁移和侵袭中发挥作用。LPA存在于大多数组织中，可通过六种不同的LPA受体（LPAR1 - 6）激活细胞。虽然LPA主要促进迁移，但某些受体在某些细胞中可能具有抗迁移作用。LPA的信号传导机制尚未完全了解，在口腔癌细胞中，LPA刺激迁移所涉及的特定受体和途径尚不清楚。
对口腔癌细胞系E10、SCC - 9和D2进行研究。在划痕试验中研究细胞迁移，并在器官型三维共培养中证明侵袭情况。用蛋白质印迹法和qRT - PCR研究LPA受体的蛋白质和mRNA表达。用蛋白质印迹法和等电聚焦检查信号蛋白的激活，并使用针对特定受体和途径的药物制剂和siRNA进一步探索信号传导机制。
LPA刺激了两种口腔癌细胞系E10和SCC - 9中的细胞迁移，但对D2细胞有轻微抑制作用。受体表达谱以及特定药理拮抗剂和激动剂的作用表明，LPA刺激的细胞迁移在E10和SCC - 9中是通过LPAR3介导的。此外，在这两种细胞系中，LPA的刺激均依赖于PKC活性。然而，虽然LPA在E10细胞中诱导EGFR的反式激活，且刺激的迁移被EGFR抑制剂阻断，但LPA在SCC - 9细胞中未诱导EGFR反式激活。在D2细胞中，LPA诱导EGFR反式激活，但这与这些细胞中非常高的固有迁移率减慢有关。
结果表明LPA通过LPAR3刺激口腔癌细胞迁移，进一步由PKC介导，PKC与EGFR反式激活协同作用或独立作用。
