Macrophages in tumor cell migration and metastasis

Area of Science:

• Immunology
• Oncology
• Cancer Biology

Background:

• Tumor-associated macrophages (TAMs) are key regulators of the tumor microenvironment (TME).
• TAMs exhibit diverse phenotypes and plasticity, influencing cancer progression and metastasis.
• Understanding TAMs' role is crucial for developing effective cancer therapies.

Purpose of the Study:

• To review TAM ontogeny, polarization, and their mechanisms in promoting tumor cell migration and metastasis.
• To explore the impact of chemotherapy and host factors (diet, obesity, race) on TAMs and cancer progression.
• To highlight the need for further research into TAMs for refining cancer treatment strategies.

Main Methods:

• Literature review of TAM ontogeny, polarization, and function in metastasis.
• Analysis of how TAMs influence tumor cell migration via EMT, ECM remodeling, and intravasation.
• Discussion of chemotherapy's dual role and host factors affecting TAMs.

Main Results:

• TAMs induce epithelial-mesenchymal transition (EMT) and promote extracellular matrix (ECM) remodeling, facilitating tumor cell migration.
• TAMs provide chemotactic signals for tumor cell dissemination and intravasation into the bloodstream.
• Chemotherapy can repolarize TAMs for anti-tumor effects but may also drive relapse and metastasis.

Conclusions:

• TAMs are critical drivers of cancer metastasis through multiple mechanisms.
• Chemotherapy's impact on TAMs is complex, potentially leading to relapse.
• Patient-specific factors like diet, obesity, and race significantly influence TAMs and cancer outcomes, necessitating personalized treatment approaches.