PURPOSE In our research we investigated immunohistochemical expression of cell cycle proteins protein p21, cyclin D1 and cyclin E in physiological endometrium (n = 15), hyperplastic endometrium (n = 61), and post hormone replacement therapy endometrium (n = 24). MATERIAL AND METHODS We performed immunohistochemical analysis of selected cell cycle proteins in 100 specimens of human endometrium...

Recent studies suggest that cyclin D1 mediates progression of hepatocytes through G1 phase of the cell cycle. The present study further examines the regulation of cyclin D1-dependent kinase activity and the interplay between cyclin D1 and other G1phase regulatory proteins during liver regeneration. After 70% partial hepatectomy in rats, there was upregulation of kinase activity associated with ...

UNLABELLED Deregulation of cell cycle control is a hallmark of cancer. The primary cyclins (A, B1, D1, D3 and E) are crucial for cell cycle progression. Secondary cyclins (C and H) have putative indirect effects on cell cycle propulsion and are not previously evaluated in breast cancer. We have examined protein expression and gene amplification of cyclins in breast carcinomas and correlated the...

Proliferation of oligodendrocyte progenitor (OP) cells is a crucial process controlling myelination in the CNS. Previous studies demonstrated a correlation between OP proliferation rate and cyclin E/cyclin-dependent kinase-2 (cdk2) activity. To establish a causal link between cyclin E/cdk2 activity and OP proliferation, we selectively modulated cdk2 activity in vitro by transfection of cultured...

Reversible phosphorylation of nuclear proteins is required for both DNA replication and entry into mitosis. Consequently, most cyclin-dependent kinase (Cdk)/cyclin complexes are localized to the nucleus when active. Although our understanding of nuclear transport processes has been greatly enhanced by the recent identification of nuclear targeting sequences and soluble nuclear import factors wi...

Proteins involved in the G1 phase of the cell cycle are aberrantly expressed, sometimes in mutated forms, in human cancers including human hepatocellular carcinoma. Upon attack by a DNA-damaging anticancer drug, a cell arrests at the G1 phase; this is a safety feature prohibiting entry of DNA-damaged cells into S-phase. p21WAF1/CIP1 prevents damag...

III. Cyclins and the cell cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 A. Major players in cell cycle control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 B. H u m a n cyclins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Transient induction of the cyclin E gene in late G1 gates progression into S. We show that this event is controlled via a cyclin E repressor module (CERM), a novel bipartite repressor element located near the cyclin E transcription start site. CERM consists of a variant E2F-binding site and a contiguous upstream AT-rich sequence which cooperate during G0/G1 to delay cyclin E expression until la...

Cyclin E, HER-2 and p53, are considered as major prognostic markers in breast cancer. As they are related in patho-clinical level, we aimed to check if they have any direct interaction on expression of each other. To study the effect of cyclin E on HER-2 expression, cell lines stably overexpressing cyclin E or its low molecular weight (LMW) isoforms were generated. To understand the results of ...

We have previously shown that many cell cycle regulatory gene products are markedly affected by infection of primary fibroblasts with human cytomegalovirus (HCMV) (F. M. Jault, J. M. Jault, F. Ruchti, E. A. Fortunato, C. Clark, J. Corbeil, D. D. Richman, and D. H. Spector, J. Virol. 69:6697-6704, 1995). One of these proteins, cyclin E, is a key determinant of cell cycle progression during G(1),...