Apoptosis y Helicobacter pylori: un nuevo modelo en oncogénesis infecciosa

En los ultimos 60 anos se ha apreciado una clara disminucion en la incidencia del cancer gastrico; producida de manera paulatina y global con gran variabilidad geografica; ya que en paises como Chile, China, Colombia o Irlanda mantienen una prevalencia alta, llegando a ser la neoplasia m as frecuente para ambos sexos; representando la segunda causa de mortalidad relacionada con cancer en el mundo. El nexo de union entre carcinoma g astrico e infeccion por Helicobacter pylori cada vez adquiere mas relevancia reforzando el papel de esta infeccion como factor de oncogenesis, siendo recientemente clasificado por la Organizacion Mundial de Salud (OMS) como carcinoma tipo I, y que una vez que ingresa a la cavidad gastrica por v ia oral, gracias a sus determinantes de patogenicidad logra evadir los mecanismos de defensa del huesped y se adhiere, coloniza y multiplica en las celulas epiteliales g astricas, liberando una serie de citocinas que producen un infiltrado inflamatorio, ocasionando gastritis aguda que puede evolucionar tras un proceso prolongado a cronica y luego a la aparicion de ulcera p eptica (enfermedad ulcero -peptica), que finalmente y junto a la atrofia g astrica con zonas de metaplasia enterica, se constituye en condicion de riesgo para el cancer g astrico, el cual se relaciona con una alta proliferacion celular y una disminucion de la apoptosis, asociado principalmente a proteinas muy patogenicas presentes en H. pylori, denominadas CagA y VacA. Intentamos revisar la influencia de la infeccion por H. pylori en la genesis del cancer g astrico asociando la apoptosis como nexo principal. Title Apoptosis and Helicobacter pylori: a new model for infectious oncogenesis Abstract In the last 60 years the incidence of gastric cancer has clearly come to a diminution. This type of cancer has been produced gradually and with a great geographic variability around the globe, since in countries like Chile, China, Colombia or Ireland have maintained a high prevalence, becoming the most common neoplasm for both sex in these regions and representing the second cause of death related to cancer. The bond between gastric cancer and infection by Helicobacter pylori has become more relevant, emphasizing the role of this infection as a factor on carcinoma and has been recently classified by the World Organization of Heath as a type I cancer risk infection, because the gastric cavity colonization, avoiding the host defences, using its pathogenic determinants, leads to an effective multiplication and infection. A series of cytokines that produce an inflammatory infiltrate are liberated by the microorganism, generating a keen gastritis that can evolve after a prolonged process into a chronic gastritis and then it might transform into peptic ulcers. These last ones may conduce to gastric atrophy with zones of enteric neoplasm, a risky condition for gastric cancer which relates to a high cell proliferation and diminution of the apoptosis, normally associated to very pathogenic proteins called CagA and VacA which are present in the bacilli. We review the link among Helicobacter pylori infection and gastric cancer taking into account the apoptosis process.