Hydrogen Sulfide Makes Cancer Cells More Sensitive to Photothermal Therapy
Typically, toxic gas hydrogen sulfide has a new application in cancer treatment. Researchers have recently found that it can support photothermal therapy (PTT) for treating cancer in a study published in the journal Angewandte Chemie International Edition.
A team of researchers from the National University of Singapore revealed that an adjuvant releasing hydrogen sulfide can cause tumor cells to lose their natural heat protection, significantly increasing their sensitivity to PTT ().
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While inhaling gaseous hydrogen sulfide is usually lethal as it suppresses the respiratory chain in mitochondria, researchers found that delivering molecular hydrogen sulfide in small amounts to cells has a different effect.
It functions as a messenger molecule and plays a role in cancer cell growth. Leveraging this knowledge, the team focused on studying the impact of hydrogen sulfide on the heat protection mechanisms of tumor cells.
Hydrogen Sulfide Could be Used to Support Photothermal Therapy for Cancer
The motivation behind this approach stems from the fact that tumor cells possess the ability to shield themselves from excessive heat. Photothermal therapy aims to "boil" cancer cells from within, using a photosensitizer introduced into the cells to convert incoming laser light into heat.However, tumor cells respond to this heat by ramping up the production of heat shock proteins (HSP), thereby reducing the effectiveness of the treatment (). They targeted the production of HSPs by disrupting the mitochondrial respiration process, which is crucial for generating the energy equivalents required by cells to produce HSPs.
They found that hydrogen sulfide when released in appropriate amounts within tumor cells, disrupts mitochondrial respiration, suppresses HSP production, and hampers the ability of tumor cells to protect themselves.
The team chose an FDA-approved drug called anethole tritone as a hydrogen sulfide donor. This drug, originally used for treating dry mouth and stimulating bile secretion, releases hydrogen sulfide continuously when broken down in the cell.
To complete the photothermal therapy, the researchers combined a derivative of anethole tritone with copper sulfide nanodiscs, which act as a photosensitizer to efficiently convert near-infrared light into heat.
Remarkably, a single-dose treatment using this adjuvant-photosensitizer combination led to the complete eradication of breast tumors in laboratory mice within just a few days. Furthermore, the researchers observed that the adjuvant allowed PTT to be performed at lower temperatures, minimizing damage to healthy surrounding tissue.
Based on their findings, they proposed using hydrogen sulfide donor adjuvants as an energy remodeling approach for more effective photothermal therapy. Overall, this groundbreaking study highlights the potential of hydrogen sulfide in supporting cancer treatment through photothermal therapy ().
By leveraging the unique properties of this compound and carefully designing the treatment approach, researchers have achieved promising results in preclinical experiments, providing a new avenue for combating cancer.
References:
- Gas-Mediated Tumor Energy Remodeling for Sensitizing Mild Photothermal Therapy - (https:onlinelibrary.wiley.com/doi/10.1002/anie.202304312)
- Nanoparticle-Mediated Photothermal Therapy Limitation in Clinical Applications Regarding Pain Management - (https:www.ncbi.nlm.nih.gov/pmc/articles/PMC8951621/)
- Recent advances in selective photothermal therapy of tumor - (https:jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-021-01080-3)