Cellular mechanisms of the relationship between breast cancer and aging
Why aging provokes the occurrence of breast cancer
Thanks to a study conducted at the Lawrence National Laboratory in Berkeley (USA), it became possible to get some answers to long-burning questions.
In the process of aging, there is an increase in the concentration of multipotent cells – adult stem cells, which have long been considered the main cause of many cases of breast cancer. At the same time, there is a decrease in the number of myoepithelial cells that serve as a lining for luminal cells, which combine to create milk ducts. In addition, it is believed that myoepithelial cells play the role of natural tumor suppressors.
Epithelial cells of the human thoracic ducts (ECG) are one of the few examples of epithelial tissues available for research in almost unlimited quantities due to regularly performed mastectomy (breast removal) and cosmetic breast reduction. In addition, over thirty years of research, scientists have developed a unique technology for ECG cultivation. All this made it possible to collect and analyze a huge collection of a wide variety of ECG samples, which included cells obtained from women of literally all ages.
As shown by Mr. Lebarge's group, in the samples of epithelial cells of older women, there is a decrease in the total number of myoepithelial cells and a simultaneous increase in the number of luminal cells producing the protein keratin-14 and integrin-alpha-6, a phenotype that in women under 30 years of age is produced only in myoepithelial cells. This, scientists believe, indicates a change in the nature of an increasing number of luminal cells formed from defective multipotent stem cells that could not fully differentiate into either luminal or myoepithelial cells with age.
Brown shows keratin-14 secreted by cells. In the tissues of a young woman (left), this protein is produced only by myoepithelial cells located along the borders of the milk ducts. On the right is a sample of cells of a 76-year-old woman.
Thus, with age, there is not only a change in the balance in the generation of luminal and myoepithelial cells, but also a transformation of the functional spectrum of multipotent stem cells, and all together this leads to an increase in the risk of potential malignant degeneration. And what else can we expect from undifferentiated cells, moreover, descended from defective stem "progenitors", the number of which increases with age...
The results of the study are published in the journal Cancer Research (Garbe et al., Accumulation of multipotent progenitors with a basal differentiation bias during aging of human mammary epithelia).
Prepared based on the materials of the Lawrence Berkeley National Laboratory:
Aging and Breast Cancer. Berkeley Lab Researchers Uncover Cellular Basis for Age-related Breast Cancer Vulnerability.
Portal "Eternal youth" http://vechnayamolodost.ru06.06.2012