Women's Health Services, Gynecological Oncology Research, Henry Ford Health System, One Ford Place, Room 4D99, Detroit, MI 48202, USA.
Cancer Chemother Pharmacol. 2011 Nov;68(5):1273-83. doi: 10.1007/s00280-011-1595-y. Epub 2011 Mar 29.
Eicosanoid-related enzymes have been implicated in the pathogenesis of various cancers. Little is known about the relevance of lipoxygenase pathway to ovarian cancer growth. In this study, we examined the role of 12-lipoxygenase (12-LOX), the main human 12-HETE generating enzyme, in the regulation of proliferation and survival in epithelial ovarian cancer.
Immunohistological analysis of 12-LOX expression in high-grade serous ovarian carcinoma and normal ovarian epithelium tissues was performed. The presence of 12-LOX-12-HETE system was confirmed in two epithelial ovarian cancer (EOC) cell lines, OVCAR-3 and SK-OV-3, using RT-PCR, Western blot and LC/MS analysis. The effects of N-benzyl-N-hydroxy-5-phenyl-pentanamide (BMD-122), a specific 12-LOX inhibitor, on cell growth, survival, apoptosis, and cell signaling were determined.
We found that a significantly higher level of 12-LOX expression in high-grade serous ovarian carcinoma compared to normal ovarian epithelium. OVCAR-3 and SK-OV-3 were found to express high level of 12-LOX mRNA and protein. Both EOC increased their 12-HETE production when incubated with arachidonic acid. BMD-122 inhibited the EOC growth in a dose-dependent fashion. Purified 12-HETE significantly reversed such inhibitory effects of BMD-122. In addition, BMD-122 blocked the MAPK signaling pathway by inhibiting the phosphorylation of ERK and induced a ~20-30% increase in the EOC apoptosis. Down-regulation of the 12-LOX expression using 12-LOX siRNA also resulted in markedly reduction in cell growth.
These data suggest that 12-LOX is involved in the regulation of ovarian cancer cell growth and survival and is a potential new therapeutic target.
类二十烷酸相关的酶已被牵涉到各种癌症的发病机制中。人们对脂氧合酶途径与卵巢癌生长的相关性知之甚少。在这项研究中，我们研究了 12-脂氧合酶（12-LOX），主要的人类 12-HETE 生成酶，在调节上皮性卵巢癌增殖和存活中的作用。
通过免疫组织化学分析高级别浆液性卵巢癌和正常卵巢上皮组织中 12-LOX 的表达。使用 RT-PCR、Western blot 和 LC/MS 分析，在两种上皮性卵巢癌细胞系（OVCAR-3 和 SK-OV-3）中证实了 12-LOX-12-HETE 系统的存在。使用 N-苄基-N-羟基-5-苯基戊酰胺（BMD-122），一种特异性的 12-LOX 抑制剂，测定对细胞生长、存活、凋亡和细胞信号转导的影响。
我们发现高级别浆液性卵巢癌中 12-LOX 的表达水平明显高于正常卵巢上皮。发现 OVCAR-3 和 SK-OV-3 表达高水平的 12-LOX mRNA 和蛋白。用花生四烯酸孵育时，两种上皮性卵巢癌细胞都增加了 12-HETE 的产生。BMD-122 以剂量依赖的方式抑制 EOC 的生长。纯化的 12-HETE 显著逆转了 BMD-122 的这种抑制作用。此外，BMD-122 通过抑制 ERK 的磷酸化阻断 MAPK 信号通路，并诱导上皮性卵巢癌细胞凋亡增加约 20-30%。用 12-LOX siRNA 下调 12-LOX 表达也导致细胞生长明显减少。
这些数据表明 12-LOX 参与调节卵巢癌细胞的生长和存活，是一个潜在的新的治疗靶点。
