Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy

Christian Harry Allen; Robyn Skillings; Duale Ahmed; Sarita Cuadros Sanchez; Kaitlyn Altwasser; George Hilan; William G. Willmore; Vinita Chauhan; Edana Cassol; Sangeeta Murugkar

doi:10.1117/1.JBO.28.7.076501

Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy

Christian Harry Allen, Robyn Skillings, Duale Ahmed, Sarita Cuadros Sanchez, Kaitlyn Altwasser, George Hilan, William G. Willmore, Vinita Chauhan, Edana Cassol, Sangeeta Murugkar

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Significance: Altered lipid metabolism of cancer cells has been implicated in increased radiation resistance. A better understanding of this phenomenon may lead to improved radiation treatment planning. Stimulated Raman scattering (SRS) microscopy enables label-free and quantitative imaging of cellular lipids but has never been applied in this domain. Aim: We sought to investigate the radiobiological response in human breast cancer MCF7 cells using SRS microscopy, focusing on how radiation affects lipid droplet (LD) distribution and cellular morphology. Approach: MCF7 breast cancer cells were exposed to either 0 or 30 Gy (X-ray) ionizing radiation and imaged using a spectrally focused SRS microscope every 24 hrs over a 72-hr time period. Images were analyzed to quantify changes in LD area per cell, lipid and protein content per cell, and cellular morphology. Cell viability and confluency were measured using a live cell imaging system while radiation-induced lipid peroxidation was assessed using BODIPY C11 staining and flow cytometry. Results: The LD area per cell and total lipid and protein intensities per cell were found to increase significantly for irradiated cells compared to control cells from 48 to 72 hrs post irradiation. Increased cell size, vacuole formation, and multinucleation were observed as well. No significant cell death was observed due to irradiation, but lipid peroxidation was found to be greater in the irradiated cells than control cells at 72 hrs. Conclusions: This pilot study demonstrates the potential of SRS imaging for investigating ionizing radiation-induced changes in cancer cells without the use of fluorescent labels.

Original language	English
Article number	076501
Journal	Journal of Biomedical Optics
Volume	28
Issue number	7
DOIs	https://doi.org/10.1117/1.JBO.28.7.076501
State	Published - Jul 1 2023
Externally published	Yes

Funding

This research was supported (S.M., E.C., and W.G.W.) by the Discovery Grant program of the Natural Sciences and Engineering Research Council of Canada (NSERC). The MCF7 cells were a kind gift from Dr. Martin Holcik in the Health Sciences department at Carleton University. Our sincere thanks to Prof. Anatoli Ianoul and Prof. Jeff Manthorpe in the Department of Chemistry, Carleton University, for providing standard samples for calibration. We would like to thank Prof. Andrew Jirasek and Dr. Quinn Matthews at the University of British Columbia for helpful discussions, as well Justin R. Gagnon, Amiel Beausoleil-Morrison, and Connor Mcnairn in the LLAMPE team, Department of Physics, for help with SRS imaging setup characterization.

Funders	Funder number
Natural Sciences and Engineering Research Council of Canada

Keywords

ionizing radiation
lipids imaging
stimulated Raman scattering microscopy

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1117/1.JBO.28.7.076501

Cite this

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title = "Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy",

abstract = "Significance: Altered lipid metabolism of cancer cells has been implicated in increased radiation resistance. A better understanding of this phenomenon may lead to improved radiation treatment planning. Stimulated Raman scattering (SRS) microscopy enables label-free and quantitative imaging of cellular lipids but has never been applied in this domain. Aim: We sought to investigate the radiobiological response in human breast cancer MCF7 cells using SRS microscopy, focusing on how radiation affects lipid droplet (LD) distribution and cellular morphology. Approach: MCF7 breast cancer cells were exposed to either 0 or 30 Gy (X-ray) ionizing radiation and imaged using a spectrally focused SRS microscope every 24 hrs over a 72-hr time period. Images were analyzed to quantify changes in LD area per cell, lipid and protein content per cell, and cellular morphology. Cell viability and confluency were measured using a live cell imaging system while radiation-induced lipid peroxidation was assessed using BODIPY C11 staining and flow cytometry. Results: The LD area per cell and total lipid and protein intensities per cell were found to increase significantly for irradiated cells compared to control cells from 48 to 72 hrs post irradiation. Increased cell size, vacuole formation, and multinucleation were observed as well. No significant cell death was observed due to irradiation, but lipid peroxidation was found to be greater in the irradiated cells than control cells at 72 hrs. Conclusions: This pilot study demonstrates the potential of SRS imaging for investigating ionizing radiation-induced changes in cancer cells without the use of fluorescent labels.",

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author = "Allen, {Christian Harry} and Robyn Skillings and Duale Ahmed and Sanchez, {Sarita Cuadros} and Kaitlyn Altwasser and George Hilan and Willmore, {William G.} and Vinita Chauhan and Edana Cassol and Sangeeta Murugkar",

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Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy

Abstract

Funding

Keywords

UN SDGs

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