English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Normal human lung fibroblast diploid cells, WI-38, become senescent after a definite number of divisions. VA-13 is a line of immortalized cells established by transformation of WI-38 cells by SV40 virus. To determine whether SV40 large T (SV40-T) antigen is essential for this immortalization of WI-38 cells we introduced an antisense gene for T antigen into VA-13. Two morphologically different types of antisense transformant (VA-AS5-8 and VA-AS37-8) were obtained. In both antisense transformants the expression of T antigen was reduced by more than 70% as compared to that in the parent cells. The morphology of the antisense transformants indicated a partial conversion to the senescent phenotype of WI-38. The relative number of cells in the S phase of the antisense transformants was decreased as compared to that in cultures of VA-13 and about 50% of cells were at G1/0. The doubling time of the transformants was prolonged to close to the doubling time of WI-38. The level of expression of retinoblastoma protein (pRB) complexed with SV40-T antigen of the antisense transformants was significantly decreased although the level of total pRB was much higher than that in VA-13. The pRB was present exclusively in the underphosphorylated form. Thus, the decreased level of formation of the complex between SV40-T and pRB or the underphosphorylation of pRB may explain the suppression of growth of antisense transformants. Together, these results show that an antisense gene for SV40-T antigen can efficiently block the cell proliferation and the cell immortalization of VA-13 cells.

Phenotypic Conversion of SV40-Immortalized Human Diploid Fibroblasts to Senescing Cells by Introduction of an Antisense Gene for SG40-T Antigen.