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Hereditary Breast and Ovarian Cancer
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Moreover, tests (not usually recommended as part of a routine breast cancer workup) may be conducted for ploidy and cell proliferation rate. The cells containing normal amount of DNA are described as diploid, and the cells containing abnormal amount of DNA are described as aneuploid. The rate of cancer cell division can be estimated by the S-phase fraction or a Ki-67 test. Ki-67 is a nuclear protein of 359 kDa encoded by Ki-67 gene located on the long arm of chromosome 10 (10q26.2). Ki-67 expression increases with cell growth and is required for maintaining cell proliferation, DNA metabolic process, cellular response to heat, meiosis, and organ regeneration. The cancer cells with a high S-phase fraction or Ki-67 labeling index divide more rapidly, suggesting a more aggressive cancer [21]. Further, S100A14 and S100A16 are recently identified cancer biomarkers that play a potential role in tumor progression. Higher expression levels of S100A14 and S100A16 proteins in breast cancer appear to be significantly associated with a younger age (<60 years), ER-negative status, HER2-positive status, and a poorer prognosis (Figure 30.2) [22].
Angiogenesis and Roles of Adhesion Molecules in Psoriatic Disease
Published in Siba P. Raychaudhuri, Smriti K. Raychaudhuri, Debasis Bagchi, Psoriasis and Psoriatic Arthritis, 2017
Asmita Hazra, Saptarshi Mandal
The S100 proteins are a family of low-molecular-weight (9–13 kDa), ubiquitously expressed vertebrate proteins. They are called S100 because of their solubility in a 100% saturated solution with ammonium sulfate at neutral pH, as discovered by B. W. Moore in 1965. Each of them has two calcium binding EF-hand motifs in the monomer and forms antiparallel homodimers and occasionally heterodimers within themselves (e.g., S100A8/A9) and other proteins. They are not enzymes, but they are calcium-activated molecular switches similar to calmodulin or troponin C. They have pleiotropic intracellular and extracellular functions, for example, proliferation, differentiation, migration, energy metabolism, Ca2+ homeostasis, inflammation, and cell death. There are at least 25 members of S100, and some of their specific functions include scavenging of ROS and NO (i.e., S100A8/A9), cytoskeleton assembly (e.g., S100A1, S100A4, S100A6, and S100A9), membrane protein docking and trafficking (e.g., S100A10 and S100A12), transcription regulation and DNA repair (e.g., S100A4, S100A11, S100A14, and S100B), cell differentiation (e.g., S100A6, S100A8/A9, and S100B), release of cytokines and antimicrobial agents (degranulation) (e.g., S100A8/A9, S100A12, and S100A13), muscle cell contractility (e.g., S100A1), cell growth and migration (e.g., S100A4, S100A8/A9, S100B, and S100P), and apoptosis (e.g., S100A6, S100A9, and S100B). The S100 proteins, once extracellular, are saturated with calcium and do not act as a calcium sensing switch, but can now scavenge other transition metal ions, for example, Zn, Cu, and Mn, which might be part of their antimicrobial action.
S100B protein: general characteristics and pathophysiological implications in the Central Nervous System
Published in International Journal of Neuroscience, 2022
Ana Cristina Arrais, Lívia Helena M. F. Melo, Bianca Norrara, Marina Abuquerque B. Almeida, Kalina Fernandes Freire, Acydalia Madruga M. F. Melo, Lucidio Clebeson de Oliveira, Francisca Overlânia Vieira Lima, Rovena Clara G. J. Engelberth, Jeferson de Souza Cavalcante, Dayane Pessoa de Araújo, Fausto Pierdoná Guzen, Marco Aurelio M. Freire, José Rodolfo L. P. Cavalcanti
S100 proteins are present in all cells of chondrogenic origin, whether normal, arthritic or neoplastic. The expression of S100A1 is associated with the differentiation status of human articular chondrocytes, a fact observed in vitro (26). These members are dysregulated in some types of neoplasia and other diseases, such as gastric cancer, which presents high expression of S100A2, S100A4, S100A8, S100A10 and S100A11, as well as S100A14, which appeared as a useful classification marker and prognosis for this same type of pathology. S100A4, S100A8 and S100A11 are altered in other types of tumors, such as colorectal, pancreas and prostate, where S100A6, S100A9 and S100P also present altered expression (27).