s-adenosylhomocysteine and Ovarian-Neoplasms

High-grade serous carcinoma has a poor prognosis, owing primarily to its early dissemination throughout the abdominal cavity. Genomic and proteomic approaches have provided snapshots of the proteogenomics of ovarian cancer

Topics: Cancer-Associated Fibroblasts; Cell Line, Tumor; Cells, Cultured; Disease Progression; DNA Methylation; Female; Histones; Humans; Neoplasm Metastasis; Niacinamide; Nicotinamide N-Methyltransferase; Ovarian Neoplasms; Phenotype; Prognosis; Proteomics; S-Adenosylhomocysteine; S-Adenosylmethionine

S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are essential compounds in the carbon metabolic cycle that have clinical implications in a broad range of disease conditions. The measurement of the ratio SAM/SAH also called methylation index, has become a way of monitoring the DNA methylation of a cell which is an epigenetic event with important clinical implications in diagnosis; therefore the development of suitable methods to accurately quantify these compounds is mandatory. This work illustrates the comparison of three independent methods for the determination of the methylation index, all of them based on the chromatographic separation of the two species (SAM and SAH) using either ion-pairing reversed phase or cation exchange chromatography. The species detection was conducted using either molecular absorption spectrophotometry (HPLC-UV) or mass spectrometry with electrospray (ESI-MS/MS) as ionization source or inductively coupled plasma (DF-ICP-MS) by monitoring the S-atom contained in both analytes. The analytical performance characteristics of the three methods were critically compared obtaining best features for the combination of reversed phase HPLC with ESI-MS in the MRM mode. In this case, detection limits of about 0.5ngmL(-1) for both targeted analytes permitted the application of the designed strategy to evaluate the effect of cisplatin on the changes of the methylation index among epithelial ovarian cancer cell lines sensitive (A2780) and resistant (A2780CIS) to this drug after exposition to cisplatin.

Topics: Antineoplastic Agents; Cell Line, Tumor; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Chromatography, Reverse-Phase; Cisplatin; DNA Methylation; Drug Resistance, Neoplasm; Female; Homocysteine; Humans; Methylation; Molecular Weight; Ovarian Neoplasms; S-Adenosylhomocysteine; S-Adenosylmethionine; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry