Microenvironmental and Molecular Pathways Driving Dormancy Escape in Bone Metastases

Area of Science:

• Oncology
• Cancer Metastasis
• Bone Biology

Background:

• Bone metastases are a major cause of death in advanced cancers.
• Disseminated tumor cells (DTCs) can enter a dormant state in bone, leading to late relapse.
• Mechanisms of dormancy escape are poorly understood but critical for preventing metastasis.

Purpose of the Study:

• To review emerging evidence on how the bone microenvironment promotes dormancy escape of DTCs.
• To discuss factors within the bone niche that facilitate tumor cell reactivation.
• To evaluate therapeutic strategies targeting dormancy escape.

Main Methods:

• Literature review synthesizing current research on bone metastasis dormancy and reactivation.
• Analysis of molecular, cellular, and systemic factors influencing tumor cell persistence and escape.
• Evaluation of therapeutic interventions for managing dormant bone metastases.

Main Results:

• Bone resorption releases growth factors (e.g., TGF-β, IGF-1) that fuel reactivation.
• Disruption of osteoblast-mediated quiescence and adipocyte support promote proliferation.
• Immune suppression, ECM remodeling, and systemic factors contribute to dormancy escape.
• Epigenetic and metabolic reprogramming enable tumor cell reactivation.

Conclusions:

• The bone microenvironment actively orchestrates dormancy escape through various cues.
• Targeting osteoclast activity, immune suppression, and metabolic pathways may prevent relapse.
• Further research is needed to identify key knowledge gaps and develop effective interventions.