initiation of tumors, the development of growth, the dissemination of cancer cells, and the resistance to treatment. Stem cells have the potential to be use not only in the treatment of breast cancer but in its prevention and in its diagnoses.
Kecia Brown
Independent Scholar
See Also: Cancer Stem Cells: Overview; Mesenchymal Stem Cells; Stem Cell Niche.
Further Readings
Goldthwaite, Charles A. “Are Stem Cells Involved in Cancer?” National Institutes of Health. http://stemcells.nih.gov/info/Regenerative_Medicine/pages/2006chapter9.aspx (Accessed September 2014).
Kasai, Tomonari, et al. “Cancer Stem Cells Converted From Pluripotent Stem Cells and the Cancerous Niche.” Journal of Stem Cells & Regenerative Medicine, v.10/1 (2014).
Madjd, Thomas A. “Application of Stem Cells in Targeted Therapy of Breast Cancer: A Systematic Review.” Asian Pacific Journal of Cancer Prevention, v.441 (2006).
University of Michigan Health System. “New Breast Cancer Stem Cell Findings Explain How Cancer Spreads.” ScienceDaily (January 14, 2014). http:/www.sciencedaily.com/releases/2014/01/140114102503.htm (Accessed September 2014).
Breast: Development and Regeneration Potential
Breast: Development and Regeneration Potential
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Breast: Development and Regeneration Potential
Breast cancer is the most recurrent form of cancer among American women. The American Cancer Society estimates that about 12% of women in the United States will develop invasive breast cancer during their lifetime. Despite the fact that the current five-year survival rate is at about 90% in the United States, and in spite of the existence of advanced technologies for screening and treatment, 40% of women still undergo a mastectomy as part of their treatment. Currently, breast reconstruction is an option proposed to female patients to help them overcome any potential psychological, physical, and emotional strain caused by breast cancer management. Rates of breast reconstruction in the United States revolve around 25%.
Breast reconstruction may happen right after surgery, or at a later stage, through the use of implants, autologous tissue, or a combination of both. Standard methods of soft tissue reconstruction include autologous fat transplantation, autologous tissue flaps, and alloplastic (artificial) implants. All of these approaches present shortcomings, such as the risk of surgery, donor-site morbidity, rejection of foreign bodies, and implant migration. Research suggests that stem cells, cell-based therapies, and tissue engineering could be important in breast reconstruction.
Embryonic and adult stem cells are capable of unlimited renewal through cell division while retaining their unspecialized features and plasticity, thus enabling them to differentiate into a variety of specific cell types. Pluripotent cells are capable of differentiating into the 216 specialized cells that make up the human body, while multipotent cells are able to give rise to a more restricted number of specialized daughter cells.
Stem cells can be collected from adult or embryonic tissues and can potentially be used for regenerative therapies. The benefit of such treatment could be extended in the future to breast cancer patients who would no longer need to undergo invasive breast reconstruction surgery, or to women with partial mastectomy who would no longer need procedures aimed at correcting defects caused by a previous reconstructive surgery.
Clinical Use of Adipose-Derived Stem Cells (ASCs) and Tissue Engineering in Breast Reconstruction
Adipose-derived stem cells (ASCs) are plentiful, readily available multipotent progenitor cells residing in adipose tissue. Their therapeutic potential in experimental clinical trials and preclinical studies has been well documented. Although recognized as potentially useful for breast reconstruction, a complete understanding of the underlying biology of adipose stem cells and their interaction with other cells and growth factors is still lacking. Additionally, fat grafting, or the transfer of fat from one place in the body to another for reconstructive or aesthetic purposes, is at times associated with complications such as oil cysts or risks of forming nodules. Supplementary clinical data should thus be evaluated to ensure whether lipofilling is unsafe or whether it increases a patient’s chances of developing cancer.
Among the many potential cell-based therapies, adipose-derived stem cells (ASCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs) are among the most promising treatment options. iPSCs and ESCs have generated considerable enthusiasm because they are pluripotent, but ESCs have ethical limitations. ASCs have the ability to differentiate into chondrocytes, adipocytes, myocytes, osteoblasts, and neurons, and furthermore demonstrate a great flexibility in adapting to specific conditions of differentiation, which is key in regenerative medicine.
Clinical Trials
Often, clinical trials conducted on humans are preceded by preclinical experiments based on animal models; this is also true for ASCs. For example, in a trial of ASC-derived hepatocytes transplanted into mice with liver pathology, not only did the ASCs differentiate into hepatocytes, but they also restored liver function.
Other potential clinical uses of ASCs include the treatment of multiple sclerosis, Alzheimer’s disease, and neurologic disorders. Other ongoing preclinical trials are focusing on the treatment of diabetes and cirrhosis. Another trial has leveraged ASCs for the management of fistulas in relation to Crohn’s disease, where they control inflammation and improve healing.
In spite of such potential, a number of questions remain to be elucidated, including the cellular, molecular, and biological features of these ASCs. It is uncertain whether the therapeutic effects of these cells are related to the cells’ ability to differentiate or to paracrine activity. Additional in vivo investigation needs to take place to clarify these doubts.
Future of Regenerative Medicine
Regenerative medicine is in constant evolution, and therapies leveraging ASCs and adipose tissue hold great promise for future research and clinical applications in this field. In the past 10 years, preclinical data stemming from in vitro studies and animal models have supported the use of these therapies in clinical applications.
The enhancing effect of ASCs on autologous repair could certainly lead to improved clinical outcomes, and play a relevant role in the treatment and rejuvenation of damaged tissue. Additional data on the methods used, and on an optimal management conducive to promoting differentiation lineages, need to be gathered and tested. As research progresses, new strategies are being developed to overcome current shortcomings, boost future therapeutic implementation, and meet the challenges posed by regenerative medicine.
Morenike Trenou
Independent Scholar
See Also: Adipose: Cell Types Composing the Tissue; Adipose: Existing or Potential Regenerative Medicine Strategies; Breast Cancer; Cancer Stem Cells: Overview; Pluripotent Stem Cells, Embryonic.
Further Readings
Bunnell, B., et al. “Adipose-Derived Stem Cells for Regenerative Medicine.” Circulation Research (2007).
Hong, L., I. A. Peptan, A. Colpan, et al. “Adipose Tissue Engineering by Human Adipose-Derived Stromal Cells.” Cells Tissues Organs, v.183 (2006).
Locke, M., J. Windsor, and P. R. Dunbar. “Human Adipose-Derived Stem Cells: Isolation, Characterization and Applications in Surgery.” ANZ Journal of Surgery,