Dynamic process of prostate cancer metastasis to bone.
Prostate cancer metastasis to the bone occurs at high frequency in patients with advanced disease, causing significant morbidity and mortality. Over a century ago, the "seed and soil" theory was proposed to explain organ-specific patterns of metastases. Today, this theory continues to be relevant as we continue to discover factors involved in the attraction and subsequent growth of prostate cancer cells to the bone. These include the accumulation of genetic changes within cancer cells, the preferential binding of cancer cells to bone marrow endothelial cells, and the release of cancer cell chemoattractants from bone elements. A key mediator throughout this metastatic process is the integrin family of proteins. Alterations in integrin expression and function promote dissociation of cancer cells from the primary tumor mass and migration into the blood stream. Once in circulation, integrins facilitate cancer cell survival through interactions between other cancer cells, platelets, and endothelial cells of the target bone. Furthermore, dynamic changes in integrins and in integrin-associated signal transduction aid in the extravasation of cancer cells into the bone and in expansion to a clinically relevant metastasis. Thus, we will review the critical roles of integrins in the process of prostate cancer bone metastasis, from the escape of cancer cells from the primary tumor, to their survival in the harsh "third microenvironment" of the circulation, and ultimately to their attachment and growth at distant bone sites.
Tantivejkul
Kwanchanit
K
Department of Urology, Division of Hematology and Oncology, The Michigan Urology Center at The University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA.
Kalikin
Linda M
LM
Pienta
Kenneth J
KJ
D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary*; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion; D002465:Cell Movement; D006801:Humans; D016023:Integrins / Q000378:metabolism; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology*
D016023:Integrins