[Overexpression of cyclin A leads to S-phase arrested apoptosis].
OBJECTIVE
This study was aimed to gain an insight into the molecular basis of S-phase arrest associated apoptosis.


METHODS
The molecular expressions of Rb, cyclin A, cyclin E, CDK2 and CDC2 involved in S-phase progression were investigated by westernblot in L-2 and Br1-3pr-1 cells. Furthermore, their associated kinase activities were assayed by histone, phosphorylation.


RESULTS
The results showed that ofter PALA treatment, the expression of cyclin A increased and the expression of Bcl-2 decreased in apoptosising L-2 cell as compared with those in unapoptosising Br1-3pr-1 cell, but there were no significant differences in other molecular expressions and associated kinase activities between the above-mentioned L-2 cell and Br1-3pr-1 cell arrested at S phase after PALA treatment.


CONCLUSIONS
Cyclin A is a most potential candidate for S phase checkpoint element, and it may be able to induce the S phase arrest associated apoptosis through the Bcl-2 pathway.
Yin
H
H
Labratory Animal Center, WCUMS, Chengdu 610041, China.
Subrata
S
S
Yang
W
W
Yang
G
G
D017209:Apoptosis; D029681:Arabidopsis Proteins; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D016203:CDC2 Protein Kinase; D042846:CDC2-CDC28 Kinases; D019925:Cyclin A / Q000096:biosynthesis* / Q000235:genetics; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D016196:S Phase; D014407:Tumor Cells, Cultured
D029681:Arabidopsis Proteins; D019925:Cyclin A; D019253:Proto-Oncogene Proteins c-bcl-2; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D042846:CDC2-CDC28 Kinases; C418966:CDC2A protein, Arabidopsis; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases