Metastatic niche formation, a guide towerds improved stem cell homing

Abstract

Upon injury, stem cells can either repair or regenerate the damaged tissue. Repair results in non-functional fibrous tissue whereas with regeneration all former cells and functions revert. The major ingredients for tissue regenerations are an intact extracellular matrix (ECM) providing structure to the regenerate, proliferating stem cells to repopulate the damaged area, and surrounding cells that support the stem cells by providing growth factors. Not all tissues are able to regenerate themselves. Regenerative medicine attempts to stimulate regeneration by providing stem cells and ECM. However, homing of stem cells towards the injured tissue is not always an efficient process. By stimulating the implanted stem cells we might be able to improve tissue regeneration. Which proteins or factors should be used, remains largely unknown. However, a little more is known about the migration of cancer stem cells towards pre-metastatic niches. Because cancer stem cells have great similarity with normal stem cells (e.g. CXCR4 expression), cancer stem cell attractive proteins (e.g. CXCRL21) might be useful in attracting normal stem cells towards injured tissue.