Issue 44, 2019

The intracellular redox environment modulates the cytotoxic efficacy of single and combination chemotherapy in breast cancer cells using photochemical internalisation

Abstract

Background: Photochemical internalisation (PCI) is a light-triggered and site-specific technique that enhances the delivery of therapeutic agents to their intracellular targets using amphiphilic, photosensitizing agents. Methods: This study investigated the effect that the intracellular redox environment of 4T1 breast cancer cells exerts on PCI-facilitated delivery of the type I ribosome inactivating protein, saporin, and the topoisomerase inhibitor, mitoxantrone, either individually or in combination. Buthionine sulfoximime (BSO), a clinically used inhibitor of glutathione synthesis, and the singlet oxygen scavenger, L-histidine, were used to enhance the oxidative and reductive state of the cells respectively. Results: PCI of saporin at 30 nM was effective in reducing cellular viability, which decreased to 16% compared to “dark” controls (P < 0.01). Addition of BSO enhanced PCI efficacy by a further factor of three (P < 0.01), but addition of L-histidine completely inhibited cytotoxicity induced by PCI. The combination of the two cytotoxic agents, saporin and mitoxantrone, with PCI, elicited 14% and 17% reduction in cell viability (P < 0.01) compared to PCI with saporin alone and mitoxantrone alone respectively. Combination treatment with BSO resulted in a further significant reduction in cell viability by 18% (P < 0.01). Conclusions: Our findings show the efficacy of PCI can be manipulated and potentiated by modifying the intracellular redox environment.

Graphical abstract: The intracellular redox environment modulates the cytotoxic efficacy of single and combination chemotherapy in breast cancer cells using photochemical internalisation

Article information

Article type
Paper
Submitted
12 Qas 2019
Accepted
09 Leq 2019
First published
19 Leq 2019
This article is Open Access
Creative Commons BY license

RSC Adv., 2019,9, 25861-25874

The intracellular redox environment modulates the cytotoxic efficacy of single and combination chemotherapy in breast cancer cells using photochemical internalisation

D. K. Adigbli, H. Pye, J. Seebaluck, M. Loizidou and A. J. MacRobert, RSC Adv., 2019, 9, 25861 DOI: 10.1039/C9RA04430B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements