Infection & Neoplastic Growth 101

摘要: The role of infectious agents in the development cancer is well-established. For example, numerous RNA and DNA viruses express dedicated oncoproteins that are able to transform cells vitro induce rapid tumor formation experimental animals. Curiously, these acutely-transforming seldom associated with naturally occurring neoplasms humans or Conversely, microbial pathogens linked cancers natural hosts rarely encode acutely transforming proteins. Moreover, they tend down-regulate most their genes except for affecting cell survival, often via NF-κB pathway. This allows pre-neoplastic avoid triggering cytotoxic immunity ensuing acute inflammation. These host responses not only kill directly, but also strongly suppress new blood vessels (neovascularization), which absolutely essential neoplastic growth. Chronic inflammation, on other hand, promotes growth may even be conducive neovascularization. Thus, cancer-associated must follow “less more” principle. According this principle, minor perturbations proliferation death tolerated by host, long run, all necessary tumorigenesis.