The dysfunction of homologous and/or heterologous gap junctional intercellular communication (GJIC) has been implicated in tumorigenesis of many kinds of cells. Here we have characterized GJIC and the expression of connexins in six @entity1 @entity2 cell lines and normal lung fibroblasts ( @entity15263 ). Compared with @entity15263 , all the @entity189 cells showed reduced or little homologous GJIC. They expressed remarkably reduced connexin(Cx)43 mRNA and variable levels of @entity28292 mRNA, but neither @entity495 nor @entity28292 protein could be detected. However, using a preloading assay, transfer of @entity5384 was observed between donor @entity15263 cells and first order neighboring recipient @entity5 cells (recipient cells in 1000-fold excess). Transfer from @entity5 to @entity15263 cells under the same conditions was not seen, although increasing the ratio of donor @entity5 cells to recipient @entity15263 cells and plating the cells at low density did reveal weak transfer from @entity5 cells to @entity15263 . Transfection of @entity495 into giant cell @entity189 PG cells increased homologous communication and eliminated the rectifying behavior of heterologous communication. This indicates that the apparent rectification of dye transfer between normal and @entity5 cells was a product of low rates of heterologous transfer linked to (i) rapid dilution of the dye to below detectable limits through a very well coupled cell population ( @entity5 to @entity15263 ) and (ii) concentration of dye in immediate neighbors in a poorly coupled cell population ( @entity15263 to @entity5 cells). These results suggest that the coupling levels may need to exceed a certain threshold to allow propagation of signals over a sufficient distance to affect behavior of a cell population. We propose that the relative rates of heterologous and homologous coupling of cell populations and the 'pool size' of shared metabolites in @entity5 cells and the surrounding normal tissue are likely to be very important in the regulation of their growth.

Effective asymmetry in gap junctional intercellular communication between populations of XXXX normal lung fibroblasts and @entity2 cells.

@entity1 :: ('9606', 'Species') :: ['human'] @entity495 :: ('2697', 'Gene') :: ['Cx43'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity2 :: ('MESH:D008175', 'Disease') :: ['lung carcinoma'] @entity189 :: ('MESH:D002277', 'Disease') :: ['carcinoma'] @entity28292 :: ('10052', 'Gene') :: ['Cx45'] @entity5384 :: ('MESH:C007740', 'Chemical') :: ['calcein'] @entity15263 :: ('3131', 'Gene') :: ['HLF']
@entity1 :: (9606,Species) :: ['human']
