Rapid Evaporative Ionization Mass Spectrometry (REIMS) was used for the rapid mass spectrometric profiling of cancer cell lines. Spectral reproducibility was assessed for three different cell lines and extent of inter-class differences and intraclass variance were found to allow the identification of these cell lines based on the REIMS data. Subsequently, the NCI60 cell line panel was subjected to REIMS analysis and the resulting dataset was investigated for its distinction of individual cell lines and different tissue types of origin. Information content of REIMS spectral profiles of cell lines were found to be similar to those obtained of mammalian tissues although pronounced differences in relative lipid intensity were observed. Ultimately, REIMS was shown to detect changes in lipid content of cell lines due to Mycoplasma infection. The data show that REIMS is an attractive means to study cell lines involving minimal sample preparation and analysis times in the range of seconds.
Membrane transporters play an important role in the absorption, distribution, metabolism and excretion of drugs. The cellular accumulation of many drugs is the result of the net function of efflux and influx transporters. Efflux transporters such as P-glycoprotein/ABCB1 have been shown to confer multidrug resistance in cancer. Although expression of uptake transporters has been confirmed in cancer cells, their role in chemotherapy response has not been systematically investigated. In the present study we have adapted a fluorescence-based cytotoxic assay to characterize the influence of key drug-transporters on the toxicity of approved anticancer drugs. Co-cultures of fluorescently labeled parental and transporter-expressing cells (expressing ABCB1, ABCG2 or OATP2B1) were screened against 101 FDA-approved anticancer drugs, using a novel, automated, triple fluorescence-based cytotoxicity assay. By measuring the survival of parental and transporter-expressing cells in co-cultures, we identify those FDA-approved anticancer drugs, whose toxicity is influenced by ABCB1, ABCG2 or OATP2B1. In addition to confirming known substrates of ABCB1 and ABCG2, the fluorescence-based cytotoxicity assays identified anticancer agents whose toxicity was increased in OATP2B1 expressing cells. Interaction of these compounds with OATP2B1 was verified in dedicated transport assays using cell-impermeant fluorescent substrates. Understanding drug-transporter interactions is needed to increase the efficacy of chemotherapeutic agents. Our results highlight the potential of the fluorescence-based HT screening system for identifying transporter substrates, opening the way for the design of therapeutic approaches based on the inhibition or even the exploitation of transporters in cancer cells.
Electronic supplementary material
The online version of this article (10.1007/s00204-019-02417-6) contains supplementary material, which is available to authorized users.
A recently proposed
strategy to overcome multidrug resistance (MDR)
in cancer is to target the collateral sensitivity of otherwise resistant
cells. We designed a library of 120 compounds to explore the chemical
space around previously identified 8-hydroxyquinoline-derived Mannich
bases with robust MDR-selective toxicity. We included compounds to
study the effect of halogen and alkoxymethyl substitutions in R5 in
combination with different Mannich bases in R7, a shift of the Mannich
base from R7 to R5, as well as the introduction of an aromatic moiety.
Cytotoxicity tests performed on a panel of parental and MDR cells
highlight a strong influence of experimentally determined p
K
a
values of the donor atom moieties, indicating
that protonation and metal chelation are important factors modulating
the MDR-selective anticancer activity of the studied compounds. Our
results identify structural requirements increasing MDR-selective
anticancer activity, providing guidelines for the development of more
effective anticancer chelators targeting MDR cancer.
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