Abstract
Introduction
Breast cancer ranked the most prevalence malignancies among women in Hong Kong with 13% mortality rate in 2021. Photodynamic therapy (PDT) is a cancer therapeutic approach via the combination of a photosensitizer (PS), light, and oxygen to generate reactive oxygen species leading to cancer cell destruction. Continuous laser is commonly applied as the light source in PDT. However, recent studies reported that intense pulsed light (IPL) could be an alternative option for PDT with an enhanced phototoxicity compared to the continuous laser used in 2D cell models. However, in vitro PDT studies on breast cancer usually ignored the effects of hormones. Hence, this study investigated the PDT efficacy using IPL via 3D breast cancer spheroids cultured in a simulated hormonal microenvironment.
Method
The MCF7 3D spheroids were cultured by the agarose-based liquid overlay method in a simulated hormonal microenvironment with estrogen and progesterone. After that, the spheroid size was measured and incubated with Hexyl-ALA at 4, 8, and 24 hours. The protoporphyrin IX (PpIX) generated from Hexyl-ALA was measured using flow cytometry and confocal microscopy. The PDT phototoxicity activated by IPL or continuous laser at 1, 2, and 4 J/cm2 were measured by MTT assay.
Results & Discussion
The PpIX generation in 3D spheroids was optimal at 8 hrs incubation. At 50μM, 4J/cm 2 by IPL or continuous laser activation with both hormones, a 25% and 10% higher phototoxicity was obtained than no hormonal supplement counterparts.
Conclusion
This study evident that IPL enhanced PDT efficacy on breast cancer 3D spheroids in a simulated hormonal microenvironment. More in-depth mechanistic studies using such model and light to investigate the relationship between hormonal changes and PDT in breast cancer deserve to be explored.
Breast cancer ranked the most prevalence malignancies among women in Hong Kong with 13% mortality rate in 2021. Photodynamic therapy (PDT) is a cancer therapeutic approach via the combination of a photosensitizer (PS), light, and oxygen to generate reactive oxygen species leading to cancer cell destruction. Continuous laser is commonly applied as the light source in PDT. However, recent studies reported that intense pulsed light (IPL) could be an alternative option for PDT with an enhanced phototoxicity compared to the continuous laser used in 2D cell models. However, in vitro PDT studies on breast cancer usually ignored the effects of hormones. Hence, this study investigated the PDT efficacy using IPL via 3D breast cancer spheroids cultured in a simulated hormonal microenvironment.
Method
The MCF7 3D spheroids were cultured by the agarose-based liquid overlay method in a simulated hormonal microenvironment with estrogen and progesterone. After that, the spheroid size was measured and incubated with Hexyl-ALA at 4, 8, and 24 hours. The protoporphyrin IX (PpIX) generated from Hexyl-ALA was measured using flow cytometry and confocal microscopy. The PDT phototoxicity activated by IPL or continuous laser at 1, 2, and 4 J/cm2 were measured by MTT assay.
Results & Discussion
The PpIX generation in 3D spheroids was optimal at 8 hrs incubation. At 50μM, 4J/cm 2 by IPL or continuous laser activation with both hormones, a 25% and 10% higher phototoxicity was obtained than no hormonal supplement counterparts.
Conclusion
This study evident that IPL enhanced PDT efficacy on breast cancer 3D spheroids in a simulated hormonal microenvironment. More in-depth mechanistic studies using such model and light to investigate the relationship between hormonal changes and PDT in breast cancer deserve to be explored.
| Original language | English |
|---|---|
| Pages (from-to) | S1452-S1452 |
| Number of pages | 1 |
| Journal | Annals of Oncology |
| Volume | 34 |
| DOIs | |
| Publication status | Published - 14 Nov 2023 |
