Bacterial colonized melanoma skin models allow to study host-microbe interactions in situ

Area of Science:

• Microbiology
• Dermatology
• Cancer Research

Background:

• Melanoma, a lethal skin cancer, may be influenced by the skin microbiome.
• Altered skin microbiome composition is observed at melanoma sites, but its role is unclear.
• Investigating the skin microbiome's role in melanoma is technically challenging.

Purpose of the Study:

• To explore the feasibility of using 3D melanoma models to study the impact of skin bacteria on melanoma progression in situ.
• To investigate the interaction between skin bacteria and melanoma cells in a controlled environment.

Main Methods:

• A commercial 3D melanoma model was cultured in an air-liquid interface.
• The model was inoculated with a diverse bacterial community from healthy human skin.
• Co-cultivation was performed for 12 days, monitoring bacterial counts, cytotoxicity, and gene expression.

Main Results:

• Bacterial counts remained comparable to in vivo levels without significant cytotoxicity.
• A decline in bacterial diversity was observed during co-cultivation.
• Microbial colonization altered melanoma gene expression, cadherin switching, and cytokine secretion (VEGF, GM-CSF), and increased melanoma marker MIA.

Conclusions:

• This study demonstrates the feasibility of using 3D melanoma models to investigate the impact of skin bacteria on melanoma biology.
• This approach allows for in situ elucidation of causal mechanisms between the skin microbiome and melanoma progression.