Salud Pública de México
versión impresa ISSN 0036-3634
Cell division is controlled by stimulatory and inhibitory systems.The origin of cancer is monoclonal, and in order that a normal cell switches its phenotype and becomes a neoplastic cell, genetic mutations must occur on it.These genetic mutations modify the products that in normal conditions the gene would codify and, finally, cause cancer. Cancer may be hereditary (due to mutations in one or both of germinal cells alleles) or sporadic (due to action of environmental mutagenic agents).The mechanisms that may cause alterations on genes may be genetic or epigenetic. Genetic mechanisms occur when structural alterations of genome are present and the epigenetic processes occur due to enzymatic alterations or alterations on its substrates. Carcinogenesis has three stages: initiation, promotion and progression.The last of these stages, progression, is exclusive of malignant transformation and implies the capacity to invade surrounding or distant tissues. For metastasis to take place, many mechanisms are required: angiogenesis, matrix degradation, cell migration, evasion of host immune response and metastatic colonization. This article presents a partial review of current bibliography about concepts related to carcinogenesis and conveys the minimum necessary information to achieve an understanding of this complex process.
Palabras llave : neoplasm; carcinogenesis; mutation; metastasis.