Department of Obstetrics and Gynecology, People's Hospital, Peking University, Beijing, China.
J Zhejiang Univ Sci B. 2011 May;12(5):346-56. doi: 10.1631/jzus.B1000192.
Recently, a high frequency of mutations in mitochondrial DNA (mtDNA) has been detected in ovarian cancer. To explore the alterations of proteins in mitochondria in ovarian cancer, a pair of human ovarian carcinoma cell lines (SKOV3/SKOV3.ip1) with different metastatic potentials was examined.
Cancer cells SKOV3.ip1 were derived from the ascitic tumor cells of nude mice bearing a tumor of ovarian cancer cells SKOV3. SKOV3.ip1 exhibited a higher degree of migration potential than its paired cell line SKOV3. The proteins in the mitochondria of these two cells were isolated and separated by 2-D gel electrophoresis. The differently expressed proteins were extracted and identified using matrix assisted laser desorption ionisation/time-of-flight/time-of-flight (MALDI-TOF/TOF), and finally a selected protein candidate was further investigated by immunohistochemistry (IHC) method in nude mice bearing tumor tissues of these two cells.
A total of 35 spots with different expressions were identified between the two cells using 2D-polyacrylamide gel electrophoresis (PAGE) approach. Among them, 17 spots were detected only in either SKOV3 or SKOV3.ip1 cells. Eighteen spots expressed different levels, with as much as a three-fold difference between the two cells. Twenty spots were analyzed using MALDI-TOF/TOF, and 11 of them were identified successfully; four were known to be located in mitochondria, including superoxide dismutase 2 (SOD2), fumarate hydratase (FH), mitochondrial ribosomal protein L38 (MRPL38), and mRNA turnover 4 homolog (MRTO4). An increased staining of SOD2 was observed in SKOV3.ip1 over that of SKOV3 in IHC analysis.
Our results indicate that the enhanced antioxidation and metabolic potentials of ovarian cancer cells might contribute to their aggressive and metastatic behaviors. The underlying mechanism warrants further study.
最近，在卵巢癌中检测到线粒体 DNA（mtDNA）的高频突变。为了探讨卵巢癌中线粒体蛋白的变化，我们检测了一对具有不同转移潜能的人卵巢癌细胞系（SKOV3/SKOV3.ip1）。
癌细胞系 SKOV3.ip1 源自带有 SKOV3 卵巢癌细胞系肿瘤的裸鼠腹水肿瘤细胞。SKOV3.ip1 显示出比其配对细胞系 SKOV3 更高的迁移潜能。这些细胞中的线粒体蛋白通过二维凝胶电泳分离和分离。使用基质辅助激光解吸电离/飞行时间/飞行时间（MALDI-TOF/TOF）提取和鉴定差异表达的蛋白质，最后通过免疫组织化学（IHC）方法在裸鼠中进一步研究这两种细胞的肿瘤组织中选定的蛋白候选物。
使用 2D-聚丙烯酰胺凝胶电泳（PAGE）方法，在两种细胞之间共鉴定出 35 个差异表达的斑点。其中，17 个斑点仅在 SKOV3 或 SKOV3.ip1 细胞中检测到。18 个斑点表达不同水平，两种细胞之间的差异高达三倍。使用 MALDI-TOF/TOF 分析了 20 个斑点，其中 11 个成功鉴定；其中 4 个已知位于线粒体中，包括超氧化物歧化酶 2（SOD2）、延胡索酸水合酶（FH）、线粒体核糖体蛋白 L38（MRPL38）和 mRNA 周转 4 同源物（MRTO4）。IHC 分析显示，SKOV3.ip1 中的 SOD2 染色比 SKOV3 增加。
我们的结果表明，卵巢癌细胞增强的抗氧化和代谢潜能可能有助于其侵袭性和转移性行为。潜在的机制需要进一步研究。
