Alvaro Macieira-Coelho – författare

In this book, tumour growth is perceived as a deviation from the normal development of the human organism. The molecular, cellular, and tissue determinants of different tumours are discussed showing that each is a different disease, often corresponding to a particular developmental stage. The natural history of several cancers illustrates how clinical incidence can be just the visible part of the iceberg, while the first changes at the tissue level sometimes occur several years before tumour growth becomes manifest. Several mechanisms are proposed to explain the distribution of cancers during the human life span and the decline of the incidence of cancers during human senescence.

Cell biologists have recently become aware that the asymmetry of cell division is an important regulatory phenomenon in the fate of a cell. During development, cell diversity originates through asymmetry; in the adult organism asymmetric divisions regulate the stem cell reservoir and are a source of the drift that contributes to the aging of organisms with renewable cell compartments. Because of the concept of semi-conservative DNA synthesis, it was thought that the distribution of DNA between daughter cells was symmetric. The analysis of the phenomenon in cells during mitosis, however, revealed the asymmetry in the distribution of the genetic material that creates the drift contributing to aging of mammals. On the other hand, cancer cells can originate from a deregulation of asymmetry during mitosis in particular during stem cell expansion. The book describes the phenomenon in different organisms from plants to animals and addresses its implications for the development of the organism, cell differentiation, human aging and the biology of cancers.