Bone metastasis: mechanisms, therapies, and biomarkers (original) (raw)

Bone Metastases: Molecular Mechanisms and Novel Therapeutic Interventions

Medicinal Research Reviews, 2012

It has been long recognized that skeleton represents one of the most favored metastatic sites for common cancers like breast and prostate. During the last decade the molecular mechanisms that are responsible for the development of bone metastasis have been gradually illuminated. It appears that the bone microenvironment has a pivotal role in this process. Metastatic tumor cells interact with bone triggering a cascade of molecular events that produce osteolytic and/or osteoblastic phenomena. In this review, we summarize and discuss the most significant factors and signaling pathways implicated in bone colonization. Moreover, based on the recent literature and data, we foresee the need for designing novel agents that will efficiently disrupt these interactions among cancer cells and bone microenvironment, bringing hope for more effective treatments.

Understanding the Progression of Bone Metastases to Identify Novel Therapeutic Targets

International Journal of Molecular Sciences

Bone is one of the most preferential target site for cancer metastases, particularly for prostate, breast, kidney, lung and thyroid primary tumours. Indeed, numerous chemical signals and growth factors produced by the bone microenvironment constitute factors promoting cancer cell invasion and aggression. After reviewing the different theories proposed to provide mechanism for metastatic progression, we report on the gene expression profile of bone-seeking cancer cells. We also discuss the cross-talk between the bone microenvironment and invading cells, which impacts on the tumour actions on surrounding bone tissue. Lastly, we detail therapies for bone metastases. Due to poor prognosis for patients, the strategies mainly aim at reducing the impact of skeletal-related events on patients' quality of life. However, recent advances have led to a better understanding of molecular mechanisms underlying bone metastases progression, and therefore of novel therapeutic targets.

The role of the bone microenvironment in skeletal metastasis

Journal of Bone Oncology, 2013

The bone microenvironment provides a fertile soil for cancer cells. It is therefore not surprising that the skeleton is a frequent site of cancer metastasis. It is believed that reciprocal interactions between tumour and bone cells, known as the ''vicious cycle of bone metastasis'' support the establishment and orchestrate the expansion of malignant cancers in bone. While the full range of molecular mechanisms of cancer metastasis to bone remain to be elucidated, recent research has deepened our understanding of the cell-mediated processes that may be involved in cancer cell survival and growth in bone. This review aims to address the importance of the bone microenvironment in skeletal cancer metastasis and discusses potential therapeutic implications of novel insights.

Emergence of Cancer-Associated Fibroblasts as an Indispensable Cellular Player in Bone Metastasis Process

Cancers

Bone metastasis is frequently complicated in patients with advanced solid cancers such as breast, prostate and lung cancers, and impairs patients’ quality of life and prognosis. At the first step of bone metastasis, cancer cells adhere to the endothelium in bone marrow and survive in a dormant state by utilizing hematopoietic niches present therein. Once a dormant stage is disturbed, cancer cells grow through the interaction with various bone marrow resident cells, particularly osteoclasts and osteoblasts. Consequently, osteoclast activation is a hallmark of bone metastasis. As a consequence, the drugs targeting osteoclast activation are frequently used to treat bone metastasis but are not effective to inhibit cancer cell growth in bone marrow. Thus, additional types of resident cells are presumed to contribute to cancer cell growth in bone metastasis sites. Cancer-associated fibroblasts (CAFs) are fibroblasts that accumulate in cancer tissues and can have diverse roles in cancer pr...

Bone metastasis: mechanisms and therapeutic opportunities

Nature Reviews Endocrinology, 2011

The skeleton is one of the most common sites for metastatic cancer, and tumors arising from the breast or prostate possess an increased propensity to spread to this site. The growth of disseminated tumor cells in the skeleton requires tumor cells to inhabit the bone marrow, from which they stimulate local bone cell activity. Crosstalk between tumor cells and resident bone and bone marrow cells disrupts normal bone homeostasis, which leads to tumor growth in bone. The metastatic tumor cells have the ability to elicit responses that stimulate bone resorption, bone formation or both. The net result of these activities is profound skeletal destruction that can have dire consequences for patients. The molecular mechanisms that underlie these painful and often incurable consequences of tumor metastasis to bone are beginning to be recognized, and they represent promising new molecular targets for therapy.

Skeletal metastases: Decreasing tumor burden by targeting the bone microenvironment

Journal of Cellular Biochemistry, 2007

Several common cancers often metastasize to the skeleton in advanced disease. Bone metastases are incurable and cause protracted, severe symptoms. Growth of tumor in bone is driven by a vicious cycle: tumor-secreted factors stimulate bone cells, which in turn release growth factors and cytokines. The bone-derived factors fuel the vicious cycle by acting back on the tumor cells. The vicious cycle offers novel targets for the treatment of advanced cancers. Treatments can inhibit bone cells (osteoclasts and osteoblasts) that are stimulated by tumor-secreted factors. Drugs can also inhibit tumor responses to factors enriched in the bone microenvironment, such as transforming growth factor-b. Animal models show that these approaches, especially combination treatments, can reduce tumor burden. The results suggest a novel paradigm in which tumor growth can be effectively inhibited by drugs that target cells in the bone microenvironment and not the tumor cells themselves.

Mechanisms, Diagnosis and Treatment of Bone Metastases

Cells

Bone and bone marrow are among the most frequent metastatic sites of cancer. The occurrence of bone metastasis is frequently associated with a dismal disease outcome. The prevention and therapy of bone metastases is a priority in the treatment of cancer patients. However, current therapeutic options for patients with bone metastatic disease are limited in efficacy and associated with increased morbidity. Therefore, most current therapies are mainly palliative in nature. A better understanding of the underlying molecular pathways of the bone metastatic process is warranted to develop novel, well-tolerated and more successful treatments for a significant improvement of patients’ quality of life and disease outcome. In this review, we provide comparative mechanistic insights into the bone metastatic process of various solid tumors, including pediatric cancers. We also highlight current and innovative approaches to biologically targeted therapy and immunotherapy. In particular, we discu...

Metastasis and bone loss: Advancing treatment and prevention

Cancer Treatment Reviews, 2010

Tumor metastasis to the skeleton affects over 400,000 individuals in the United States annually, more than any other site of metastasis, including significant proportions of patients with breast, prostate, lung and other solid tumors. Research on the bone microenvironment and its role in metastasis suggests a complex role in tumor growth. Parallel preclinical and clinical investigations into the role of adjuvant bone-targeted agents in preventing metastasis and avoiding cancer therapy-induced bone loss have recently reported exciting and intriguing results. A multidisciplinary consensus conference convened to review recent progress in basic and clinical research, assess gaps in current knowledge and prioritize recommendations to advance research over the next 5 years. The program addressed three topics: advancing understanding of metastasis prevention in the context of bone pathophysiology; developing therapeutic approaches to prevent metastasis and defining strategies to prevent cancer therapy-induced bone loss. Several priorities were identified: (1) further investigate the effects of bone-targeted therapies on tumor and immune cell interactions within the bone microenvironment; (2) utilize and further develop preclinical models to study combination therapies; (3) conduct clinical studies of bone-targeted therapies with radiation and chemotherapy across a range of solid tumors; (4) develop biomarkers to identify patients most likely to benefit from bone-targeted therapies; (5) educate physicians on bone loss and fracture risk; (6) define optimal endpoints and new measures of efficacy for future clinical trials; and (7) define the optimum type, dose and schedule of adjuvant bone-targeted therapy.

Tumor-bone cellular interactions in skeletal metastases

Journal of musculoskeletal & neuronal interactions, 2004

Human tumor cells inoculated into the arterial circulation of immunocompromised mice can reliably cause bone metastases, reproducing many of the clinical features seen in patients. Animal models permit the identification of tumor-produced factors, which act on bone cells, and of bone-derived factors. Local interactions stimulated by these factors drive a vicious cycle between tumor and bone that perpetuates skeletal metastases. Bone metastases can be osteolytic, osteoblastic, or mixed. Parathyroid hormone-related protein, PTHrP, is a common osteolytic factor, while vascular endothelial growth factor and interleukins 8 and 11 also contribute. Osteoblastic metastases can be caused by tumor-secreted endothelin-1, ET-1. Other potential osteoblastic factors include bone morphogenetic proteins, platelet-derived growth factor, connective tissue growth factor, stanniocalcin, N-terminal fragments of PTHrP, and adrenomedullin. Osteoblasts are the main regulators of osteoclasts, and stimulatio...