Mesenchymal Stem Cell Administration Attenuates Colon Cancer Progression by Modulating the Immune Component within...

Area of Science:

• Oncology
• Immunology
• Stem Cell Biology

Background:

• Solid tumors, including colorectal cancer, pose significant health challenges.
• Mesenchymal stem cells (MSCs) show therapeutic potential due to their immunomodulatory properties.

Purpose of the Study:

• To investigate the influence of mesenchymal stem cell (MSC) therapy on colorectal cancer initiation and progression.
• To elucidate the mechanisms by which MSCs modulate the tumor immune microenvironment.

Main Methods:

• Utilized human colorectal cancer cells and an immunocompetent rat model of colorectal carcinogenesis.
• Administered bone marrow (BM)-derived MSCs and analyzed tumor development, immune cell infiltration (CD68+, CD3+, CD8+, Treg), and cytokine production.
• Assessed Natural Killer (NK) cell, rTh17, and Th17 cell activities, as well as endothelial cell presence.
• Quantified the expression of miR-150 and miR-7.
• Evaluated MSC effects in combination with radiotherapy.

Main Results:

• MSC treatment significantly reduced cancer initiation and progression, decreasing tumor number and size by 50% and extending lifespan.
• MSC therapy led to decreased infiltration of CD68+ monocytes/macrophages and increased CD3+ lymphocytes.
• MSCs reprogrammed macrophages to a regulatory, phagocytic phenotype, inhibiting pro-inflammatory cytokines.
• MSC treatment modulated various immune cells, including decreased NK and rTh17 activity, reduced Treg and CD8+ T cell infiltration, and restored Th17 activity.
• Expression of miR-150 and miR-7 increased up to fivefold.
• MSC administration attenuated tumor growth and limited healthy tissue damage during radiotherapy.

Conclusions:

• Mesenchymal stem cells (MSCs) demonstrate a durable, immunomodulatory effect on colon cancer development within the tumor microenvironment.
• MSC therapy holds promise for enhancing cancer treatment strategies, including combination with radiotherapy.
• miR-150 and miR-7 are identified as potential key mediators in MSC-driven cancer growth attenuation.