9-oxo-ODAs suppresses the proliferation of human cervical cancer cells through the inhibition of CDKs and HPV oncoproteins.

Mucosal human papillomavirus (HPV) subtypes 16 and 18 are causative agents of cervical cancer, a leading cause of cancer-related deaths among women worldwide. In Japan, eggplant calyx is a folk remedy used to treat common warts. 9-oxo-(10E,12E)-octadecadienoic acid, isolated from eggplant calyx, may have antitumor effects. This study investigated the antitumor effects of 9-oxo-(10E, 12Z)-octadecadienoic acid and 9-oxo-(10E,12E)-octadecadienoic acid (9-oxo-ODAs) on human cervical cancer cells. 9-oxo-ODAs suppressed the proliferation of human cervical cancer cell lines (HeLa, and SiHa) in a concentration-dependent manner (IC50 = 25-50 µM). FCM analysis revealed that 9-oxo-ODAs induced apoptosis. Transcriptome, proteomics, and enrichment analyses revealed that treatment with 9-oxo-ODAs significantly altered the cell cycle and p53 pathways and decreased cyclin-dependent kinase 1 (CDK1) protein expression. Real-time PCR analysis demonstrated that 9-oxo-ODAs reduced CDK1 mRNA expression in a concentration-dependent manner. In vitro, 9-oxo-ODAs reduced the HPV oncoprotein expression. In ex vivo human cervical cancer tissues, 9-oxo-ODAs decreased CDK1 expression and increased cleaved caspase 3, an apoptosis marker. Further, 9-oxo-ODAs showed the potential to suppressed metastatic formation and growth of cervical cancer in vivo. These findings suggest that 9-oxo-ODAs induce cell cycle arrest and apoptosis in HPV-positive human cervical cancer cells, and this process involves CDK1. Consequently, 9-oxo-ODAs may be potential therapeutic agents for cervical cancer.

Quantitative phosphorus metabolomics using nanoflow liquid chromatography-tandem mass spectrometry and culture-derived comprehensive global internal standards.

Highly sensitive and quantitative analytical methods are essential for metabolomics. In this report, we introduce an analytical method focused on endogenous phosphorus metabolites, using nanoflow liquid chromatography-electrospray ionization tandem mass spectrometry (nanoLC-ESI-MS/MS) and culture-derived isotope-tagged metabolites as global internal standards for quantitative metabolomics. The nanoLC-ESI-MS/MS method employing a stone-arch microcolumn with amino propyl silica gel achieved good separation of phosphorus metabolites with forty- to hundred-fold increase of sensitivity compared with semimicro flow LC-ESI-MS. The quantitative reproducibility of the nanoLC-ESI-MS has been improved to the point where it is useful for studies of cellular metabolism. Focused metabolomics using culture-derived internal standards was employed to monitor 184 phosphorus-related metabolic changes in cancer cells treated with metabolic enzyme inhibitors, methotrexate, fluorouracil, and gemcitabine. We found marked perturbations of cellular metabolism, of which many, though not all, were in line with the known biological activities of these drugs.