In vitro label‐free screening of chemotherapeutic drugs using Raman microspectroscopy: Towards a new paradigm of spectralomics

Abstract

This overview groups some of the recent studies highlighting the potential application of Raman microspectroscopy as an analytical technique in preclinical development to predict drug mechanism of action and in clinical application as a companion diagnostic and in personalised therapy due to its capacity to predict cellular resistance and therefore to optimise chemotherapeutic treatment efficacy. Notably, the anthracyclines, doxorubicin and actinomycin D, elicit similar spectroscopic signatures of subcellular interaction characteristic of the mode of action of intercalation. Although cisplatin and vincristine show markedly different signatures, at low exposure doses, their signatures at higher doses show marked similarities to those elicited by the intercalating anthracyclines, confirming that anticancer agents can have different modes of action with different spectroscopic signatures, depending on the dose. The study demonstrates that Raman microspectroscopy can elucidate subcellular transport and accumulation pathways of chemotherapeutic agents, characterise and fingerprint their mode of action, and potentially identify cell-resistant strains. The consistency of the spectroscopic signatures for drugs of similar modes of action, in different cell lines, suggests that this fingerprint can be considered a "spectralome" of the drug-cell interaction suggesting a new paradigm of representing spectroscopic responses.

Numerically modelling time and dose dependent cytotoxicity

“…Furthermore, although the general shape of the curves in Figure 5 appears to be independent of exposure time, the Hill slope of a four parameter fit is seen to be exposure time dependent, as shown in Figure 7. Such a complex relationship of inverse IC50 with exposure time has been observed for the action of chemotherapeutic agents, and is understandable by considering that the endpoint or exposure time is shorter that any of the times associated with the critical rates of the cellular processes [33] . In the case of Figure 6, it can be considered that the trend of toxicity, as represented by the inverse IC50, is lower than expected for times of <24 hrs, given that the rate of loss of viability is 0.1 hr -1 , with an associated timescale of 10 hrs.…”

Data mining Raman microspectroscopic responses of cells to drugs in vitro using multivariate curve resolution-alternating least squares

“…phenotypic changes induced by the drug). [6] By investigating the evolution of the Raman bands of the drug, the drug metabolites and the rest of the components, one can establish the composition ratio of the drug and the molecules which are affected by the drug. [7][8][9][10] Different biomolecules (i.e.…”

Advancing Raman microspectroscopy for cellular and subcellular analysis: towards in vitro high-content spectralomic analysis

“…At doses above their median inhibitory concentrations, the signatures also exhibit characteristics of intercalation, as shown DOC and ACT, indicating that they can have multiple modes of action. [48] Monitoring the time evolution of drug distribution within the cell, the spectroscopic signatures of the chemical interaction in the subcellular regions can be identified, and associated with the characteristic modes of action of the drug. The signatures are consistent for drugs of similar modes of action, and thus can be exploited as a rapid in vitro tool for pre-screening of candidate drugs and a guide to design strategies for chemotherapeutics.…”