Lysophosphatidic Acid Receptors Determine Tumorigenicity and Aggressiveness of Ovarian Cancer Cells
Lysophosphatidic Acid Receptors Determine Tumorigenicity and Aggressiveness of Ovarian Cancer Cells
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DOI：
10.1093/jnci/djn378
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发表时间：
2008-11-19
影响因子：
10.3
通讯作者：
Mills, Gordon B.
中科院分区：
文献类型：
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作者：
Yu, Shuangxing;Murph, Mandi M.;Mills, Gordon B.
溶血磷脂酸 (LPA) 通过细胞表面 G 蛋白偶联受体 LPA1、LPA2 或 LPA3 发挥作用，引发多种细胞反应。它在人类卵巢癌的腹腔积液中含量很高，可增加细胞存活、增殖和运动性，并刺激新血管形成因子的产生。卵巢癌细胞异常表达 LPA2 和 LPA3 以及调节 LPA 产生和降解的酶，但卵巢癌细胞中这些表达变化的后果尚不清楚。分别使用小干扰 RNA (siRNA) 和慢病毒构建体抑制或增加卵巢癌细胞中 LPA1、LPA2 或 LPA3 的表达。我们通过酶联免疫吸附测定测量了 LPA 受体表达变化对细胞增殖（通过结晶紫染色）、细胞运动和侵袭（使用博伊登室）和细胞因子（白细胞介素 6 [IL-6]、白细胞介素 8 [IL-8] 和血管内皮生长因子 [VEGF]）产生的影响。在小鼠异种移植模型中评估了 LPA 受体在肿瘤生长、腹水形成和细胞因子产生中的作用。所有统计检验都是双向的。LPA 受体表达增加的 SKOV-3 细胞显示出侵袭性增加，而 siRNA 敲低则抑制迁移（P < .001，Student t 检验）和侵袭。 LPA2 或 LPA3 受体的敲低抑制了 SKOV-3 和 OVCAR-3 细胞中 IL-6、IL-8 和 VEGF 的产生。表达 LPA 受体的 SKOV-3 异种移植物形成了尺寸增大和腹水量增加的原发肿瘤。注射表达 SKOV-3 的 LPA1 的小鼠中有 75% (n = 4) 发生腹膜腔侵袭性肿瘤，而注射表达 SKOV-3 细胞的 LPA2 或 LPA3 的小鼠则有 80% (n = 5) 发生腹膜腔侵袭性肿瘤。在肝脏、肾脏和胰腺中发现了表达 LPA1、LPA2 和 LPA3 的转移性肿瘤；在骨骼肌中检测到表达 LPA2 和 LPA3 的肿瘤；在颈部淋巴结和心脏中也发现了表达LPA2的肿瘤。与表达β-半乳糖苷酶的肿瘤小鼠相比，表达LPA2或LPA3的肿瘤小鼠的存活率降低。卵巢癌发生过程中LPA2或LPA3的表达有助于卵巢癌的侵袭性，这表明LPA产生和作用的靶向可能具有治疗卵巢癌的潜力。
Lysophosphatidic acid (LPA) acts through the cell surface G protein-coupled receptors, LPA1, LPA2, or LPA3, to elicit a wide range of cellular responses. It is present at high levels in intraperitoneal effusions of human ovarian cancer increasing cell survival, proliferation, and motility as well as stimulating production of neovascularizing factors. LPA2 and LPA3 and enzymes regulating the production and degradation of LPA are aberrantly expressed by ovarian cancer cells, but the consequences of these expression changes in ovarian cancer cells were unknown.Expression of LPA1, LPA2, or LPA3 was inhibited or increased in ovarian cancer cells using small interfering RNAs (siRNAs) and lentivirus constructs, respectively. We measured the effects of changes in LPA receptor expression on cell proliferation (by crystal violet staining), cell motility and invasion (using Boyden chambers), and cytokines (interleukin 6 [IL-6], interleukin 8 [IL-8], and vascular endothelial growth factor [VEGF]) production by enzyme-linked immunosorbent assay. The role of LPA receptors in tumor growth, ascites formation, and cytokine production was assessed in a mouse xenograft model. All statistical tests were two-sided.SKOV-3 cells with increased expression of LPA receptors showed increased invasiveness, whereas siRNA knockdown inhibited both migration (P < .001, Student t test) and invasion. Knockdown of the LPA2 or LPA3 receptors inhibited the production of IL-6, IL-8, and VEGF in SKOV-3 and OVCAR-3 cells. SKOV-3 xenografts expressing LPA receptors formed primary tumors of increased size and increased ascites volume. Invasive tumors in the peritoneal cavity occurred in 75% (n = 4) of mice injected with LPA1 expressing SKOV-3 and 80% (n = 5) of mice injected with LPA2 or LPA3 expressing SKOV-3 cells. Metastatic tumors expressing LPA1, LPA2, and LPA3 were identified in the liver, kidney, and pancreas; tumors expressing LPA2 and LPA3 were detected in skeletal muscle; and tumors expressing LPA2 were also found in the cervical lymph node and heart. The percent survival of mice with tumors expressing LPA2 or LPA3 was reduced in comparison with animals with tumors expressing beta-galactosidase.Expression of LPA2 or LPA3 during ovarian carcinogenesis contributes to ovarian cancer aggressiveness, suggesting that the targeting of LPA production and action may have potential for the treatment of ovarian cancer.