Related Experiment Video
Updated: May 21, 2026
Live Imaging of Drug Responses in the Tumor Microenvironment in Mouse Models of Breast Cancer
Published on: March 24, 2013
Phototoxic effects of fluorescent protein KillerRed on tumor cells in mice
Marina V Shirmanova1, Ekaterina O Serebrovskaya, Konstantin A Lukyanov
1Nizhny Novgorod State Medical Academy, 603005 Minin Sq., 10/1, Nizhny Novgorod, Russia. Shirmanovam@mail.ru
Abstract:
KillerRed is known to be a unique red fluorescent protein displaying strong phototoxic properties. Its effectiveness has been shown previously for killing bacterial and cancer cells in vitro. Here, we investigated the photototoxicity of the protein on tumor xenografts in mice. HeLa Kyoto cell line stably expressing KillerRed in mitochondria and in fusion with histone H2B was used. Irradiation of the tumors with 593 nm laser led to photobleaching of KillerRed indicating photosensitization reaction and caused significant destruction of the cells and activation of apoptosis. The portion of the dystrophically changed cells increased from 9.9% to 63.7%, and the cells with apoptosis hallmarks from 6.3% to 14%. The results of this study suggest KillerRed as a potential genetically encoded photosensitizer for photodynamic therapy of cancer.
Insights
KillerRed, a red fluorescent protein, effectively destroyed tumor cells in mice via photodynamic therapy. This genetically encoded photosensitizer shows promise for future cancer treatments.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- KillerRed is a red fluorescent protein with known phototoxic properties.
- Previous studies demonstrated its efficacy in eliminating bacterial and cancer cells in vitro.
- This research explores its potential for in vivo cancer treatment.
Purpose of the Study:
- To investigate the phototoxicity of KillerRed on tumor xenografts in mice.
- To evaluate KillerRed as a genetically encoded photosensitizer for cancer therapy.
Main Methods:
- Utilized HeLa Kyoto cell line engineered to express KillerRed in mitochondria and fused with histone H2B.
- Irradiated tumors with a 593 nm laser to induce KillerRed photosensitization.
- Assessed cell destruction and apoptosis activation post-irradiation.
Main Results:
- Laser irradiation caused KillerRed photobleaching, confirming photosensitization.
- Significant tumor cell destruction was observed, with dystrophically changed cells increasing from 9.9% to 63.7%.
- Apoptosis hallmarks increased from 6.3% to 14% in treated cells.
Conclusions:
- KillerRed exhibits potent phototoxicity against tumor xenografts in vivo.
- The protein acts as a genetically encoded photosensitizer, inducing cell death and apoptosis.
- KillerRed presents a promising candidate for developing novel photodynamic cancer therapies.
