Endocrine disruptors (EDs) are a class of environmental toxic molecules able to interfere with the normal hormone metabolism. Numerous studies involve EDs exposure to initiation and development of cancers, including prostate cancer. In this work, three different EDs (aldrin, aroclor 1254 and chlorpyrifos (CPF)) were investigated as potential inducers of a malignant phenotype in DU145 prostate cancer cells after a chronic exposure. Epithelial to mesenchymal transition (EMT) induction, proliferation, migration, colony formation and release of metalloproteinase 2 (MMP-2) were analyzed in 50-day exposed cells to the selected EDs. As a result, aldrin and CPF exposure led to an EMT induction (loss of 16% and 14% of E-cadherin levels, respectively, compared to the unexposed cells). Aroclor and CPF presented an increased migration (134% and 126%, respectively), colony formation (204% and 144%, respectively) and MMP-2 release (137% in both cases) compared to the unexposed cells. An untargeted lipidomic analysis was performed to decipher the lipids involved in the observed transformations. As general results, aldrin exposure showed a global decrease in phospholipids and sphingolipids, and aroclor and CPF showed an increase of certain phospholipids, glycosphingolipids as well as a remarkable increase of some cardiolipin species. Furthermore, the three exposures resulted in an increase of some triglyceride species. In conclusion, some significant changes in lipids were identified and thus we postulate that some lipid compounds and lipid metabolic pathways could be involved in the acquisition of the malignant phenotype in exposed prostate cancer cells to the selected EDs.

aEpithelial to mesenchymal transition (EMT) is a biological process that plays a crucial role in cancer metastasis. Although studies regarding the EMT mechanisms are usual in terms of gene expression and protein functions, little is known about the involvement of lipids in EMT. In this work, an untargeted lipidomic analysis was performed to reveal which lipids are involved in the EMT process. DU145 prostate cancer cells were treated with TNFα, a well-known EMT inducer. After 6 hours of treatment, a decrease of cell membrane E-cadherin as well as a reduction in its gene expression were observed. Also, the mesenchymal markers Vimentin and Snail were up-regulated, suggesting that EMT started below 6 hours of treatment. Lipid extracts of untreated and TNFα-treated cells at short times were analyzed using ultra-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC-MS). Multivariate data analysis methods were applied to decipher which lipids presented significant changes after EMT induction. Among the results obtained, a significant increase of twelve unsaturated triacylglycerides (TAGs) was observed. This increase of TAGs was also observed for cells treated with TGFβ (another EMT inducer), suggesting that this feature is a common mechanism in the EMT process. In conclusion, this work reported for the first time a TAG accumulation through EMT induction. These TAG lipids could have a key role in providing cells with the energy, cell membrane components and signaling lipids necessary to guarantee the enhanced cell migration and proliferation of metastatic cells.

Important lipid changes were detected under acute and chronic UV irradiation. The lipid profile under chronic exposure may represent a lipid fingerprint of the keratinocyte differentiation phenotype.

Untargeted liquid chromatography coupled to mass spectrometry (LC-MS) analysis generates massive amounts of information-rich mass data which presents storage and processing challenges. In this work, the validation of a recently proposed procedure for LC-MS data compression and processing is presented, using as example the analysis of lipid mixtures. This method consists of a preliminary selection of the Regions of Interest of the LC-MS data (MSROI) coupled to their throughout chemometric analysis by the Multivariate Curve Resolution Alternating Least Squares method (MCR-ALS). The proposed data selection procedure is based on the search of the most significant mass traces regions with high mass densities. This allows for a drastic reduction of the MS data size and of the computer storage requirements, without any significant loss neither of spectral resolution nor of accuracy on m/z measures. The combination of the MSROI data compression and MCR-ALS data analysis procedures in the new ROIMCR procedure has the main advantage of not requiring neither the chromatographic peak alignment nor the chromatographic peak shape modelling used in many other procedures as a pre-treatment step of the data analysis. The proposed ROIMCR procedure is tested in the analysis of the LC-MS experimental data coming from different lipid mixtures and of a melanoma cell line culture sample with satisfactory results. The proposed strategy is shown to be a general, fast, reliable and easy to use method for general untargeted LC-MS metabolic and lipidomic data analysis type of studies.

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