Angiogenic switch occurs during the precancerous stage of @entity1 XXXX .

@entity1 @entity1697 @entity7 @entity5 @entity957 @entity1721 @entity189 @entity1015 @entity7944 @entity540 @entity418 @entity2280 @entity687 @entity1141
We previously reported that @entity7 ( @entity7 ) expression correlates with vessel density in @entity1 @entity1721 . However, @entity5 angiogenesis is not controlled simply by the presence of @entity7 , and is likely regulated by several angiogenic factors produced by @entity5 and host cells. The goal of the present study was to determine the angiogenic profile of precancerous and cancerous lesions of the esophagus. Expression of mRNAs for @entity7 , platelet derived endothelial cell growth factor ( @entity1015 ), @entity540 ( @entity540 ), and @entity687 was examined in six @entity418 cell lines and fresh biopsy specimens from 16 @entity1 with invasive @entity418 by RT-PCR. Immunohistochemical analyses with antibodies against @entity7 , @entity1015 , @entity540 , and @entity687 were performed on archival specimens of 60 normal esophageal mucosa, 11 @entity1141 and 49 @entity189 of the esophagus. Microvessels were stained with anti- @entity2280 antibody and quantified by counting the number of vessels in a x200 field in the most vascularized areas of the @entity5 . @entity418 cell lines and @entity5 tissues expressed mRNAs for one or more these angiogenic factors at various levels. An initial increase in vessel density and enhanced expression of @entity1015 and @entity7 were observed in @entity7944 . Vessel density was significantly higher in more advanced lesions. @entity540 and @entity687 were not expressed in @entity1697 , but expression was increased in late stage @entity957 . These findings suggest that the angiogenic switch is a very early event in the development of @entity189 . Several different angiogenic factors produced by @entity5 cells and host cells may regulate angiogenesis during different steps of esophageal carcinogenesis.
