Breast cancer is the second most common cancer in women and the fifth cause contributing to death due to the cancer condition. It is essential to deeply understand the complex cellular mechanisms leading to this disease. There are multiple connections between calcium homeostasis alterations and breast cancer in the literature, but no consensus links the mechanism to the disease prognosis. Among the cells contributing to the breast cancer are the breast telocytes, which connect through gap junctions to other cells, including cancer cells and myoepithelial cells. Multiple proteins (i.e., voltage-gated calcium channels, transient receptor potential channels, STIM and Orai proteins, ether à go-go potassium channels, calcium-activated potassium channels, calcium-activated chloride channels, muscarinic acetylcholine receptors, etc.) coupled with calcium signaling pathways undergo functional and/or expression changes associated with breast cancer development and progression, and might represent promising pharmacological targets. Unraveling the mechanisms of altered calcium homeostasis in various breast cells due to the cancer condition might contribute to personalized therapeutic approaches.
Part of the book: Calcium and Signal Transduction
Extracellular vesicles (EVs) represent a generic term for all the secreted vesicles, which include exosomes, microvesicles, and apoptotic bodies. EVs are key partners in the intercellular communication and play an essential role in multiple physiological and pathological conditions. EVs are shuttles for cargo molecules, such as RNA (mRNA, microRNA, and other noncoding RNAs), DNA, proteins (receptors, transcription factors, enzymes, and extracellular matrix proteins), and lipids. In pathological states, including cancer, EVs might represent either useful biomarkers or can be used for therapeutic purposes. Moreover, in cancer, it was demonstrated that EVs play an essential role in drug resistance. Here, we review the role played by EVs in the most common forms of cancer, with a special focus on ovarian and breast cancers.
Part of the book: Extracellular Vesicles and Their Importance in Human Health
Stem cells are defined as undifferentiated cells that are able to unlimitedly renew themselves within controlled conditions and to differentiate into a multitude of mature cell types. Skeletal muscle stem cells, represented predominantly by satellite cells, show a variable capability of self-renewal and myogenic differentiation. They were found to be involved not only in the growth of myofibers during neonatal and juvenile life but also in the regeneration of skeletal muscles after an injury. The microenvironment in which stem cells are nourished and maintained dormant preceding division and differentiation is known as “niche.” The niche consists of myofibers, which are believed to modulate the active/inactive state of the stem cells, extracellular matrix, neural networks, blood vessels, and a multitude of soluble molecules. It was observed that changes in the composition of the niche have an impact on the stem cell functions and hierarchy. Furthermore, it seems that its layout is variable throughout the entire life, translating into a decrease in the regenerative capacity of satellite cells in aged tissues. The scope of this chapter is to provide a detailed view of the changes that occur in the skeletal stem cell niche during life and to analyze their implications on tissue regeneration. Future studies should focus on developing new therapeutic tools for diseases involving muscle atrophy.
Part of the book: Background and Management of Muscular Atrophy