Immortalisation of XXXX ovarian surface epithelium with telomerase and temperature-sensitive SV40 large T antigen.

@entity43 @entity30956 @entity1 @entity986 @entity5 @entity5962 @entity3544 @entity876 @entity24 @entity2533 @entity2277 @entity2215
@entity43 is the most common form of gynaecological @entity5 . This lethal disease is thought to arise in @entity30956 ( @entity30956 ) cells. The biology of these cells is not well understood, due to the limited amount of tissue that can be obtained from a single biopsy and their limited life span in culture. To overcome these problems, we have conditionally immortalised @entity30956 cells with the catalytic subunit of telomerase ( @entity2215 ) and a temperature-sensitive form of SV40 Large T antigen ( @entity24 ). We have maintained these cells (designated @entity30956 -C2) in culture for more than 100 population doublings after introduction of the immortalising genes. Early passage @entity30956 -C2 cells have a near-tetraploid karyotype and exhibit a dual mesenchymal-epithelial phenotype, with consistent expression of @entity2277 and variable expression of cytokeratins and type III collagen, and absence of @entity5962 expression. @entity30956 -C2 cells proliferate steadily at the permissive temperature of 33 degrees C, but fail to increase in number at the nonpermissive temperature of 39 degrees C. Serum-deprived @entity30956 -C2 cells are stimulated to grow at 33 degrees C by EGF, whereas they are growth inhibited at 33 degrees C by @entity2533 in the presence or the absence of serum. When temperature shifted to the nonpermissive temperature, @entity30956 -C2 cells modulate to a more mesenchymal phenotype, and a proportion of the cells undergo senescence and/or apoptosis. Moreover, at the nonpermissive temperature, the levels of @entity876 and SV40 Large T antigen diminish, whilst the level of @entity3544 increases, whereas the level of @entity986 and telomerase activity is unchanged. This experimental system shows that expression of telomerase alone only allows limited proliferative potential of @entity30956 cells; expression of @entity24 is necessary to maintain these cells in culture for longer periods, perhaps by its ability to inactivate components of the @entity876 /Rb pathway. @entity30956 -C2 cells may be useful in studying the physiology and differentiation of @entity1 @entity30956 cells and provide insight into the poorly understood earliest stages of @entity43 .
