title: Is there a relationship between hypoxia, contact resistance, and intercellular communication?
abstract: This investigation addresses the shape of radiation survival curves of cells cultured as multicell spheroids. It is shown that spheroids of cells capable of intercellular communication by gap-junctions display survival curves lacking a radioresistant fraction of hypoxic cells. Compared to the corresponding monolayers, these spheroid survival curves exhibit a uniform increase in radioresistance due to the "contact effect". In contrast, biphasic survival curves indicative of hypoxic cells are obtained with non-communicating spheroids, however, without indication of a contact effect. Evidence is presented that this relationship between intercellular communication, hypoxia, and contact effect may possibly also hold for survival curves of solid tumors.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002450:Cell Communication; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured / Q000528:radiation effects; D003260:Contact Inhibition; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D000860:Hypoxia; D051379:Mice; D051381:Rats