Ectopic expression of the c-Myc oncoprotein prevents cell cycle arrest in response to growth-inhibitory signals, differentiation stimuli, or mitogen withdrawal. Moreover, Myc activation in quiescent cells is sufficient to induce cell cycle entry in the absence of growth factors. Thus, Myc transduces a potent mitogenic stimulus but, concomitantly, induces apoptosis in the absence of survival fac...

The deregulated expression of cyclin E as measured by the overexpression of its low molecular weight (LMW) isoforms is a powerful predictor of poor outcome in patients with breast cancer. The mechanism by which these LMW forms give tumor cells a growth advantage is not known and is the subject of this article. In this article, we provide the pathobiological mechanisms of how these LMW forms are...

Iron removal by the chelating-agent deferoxamine (DFO) arrests cell cycle progression of activated human T cells in late G1 phase, before the G1/S border. The effects of the drug on molecules that regulate progression through the cell cycle were defined. DFO (10 mumol/L) inhibited induction of transcription of the cdc2 gene, but had no effect on accumulation of cdk2, cdk4, or interleukin (IL)-2...

Cyclin E/cyclin-dependent kinase 2 complexes are essential during the cell cycle for entrance into S phase. Cyclin E expression starts in mid-G1, reaches a maximum at S-phase entrance, and undergoes proteolysis mediated by the ubiquitin pathway as the cell progresses through S phase. Laser scanning cytometry, a microscope-based cytofluorometer combining the advantages of both flow and image ana...

Adenoviruses (Ads) with deletion of E1b55K preferentially replicate in cancer cells and have been used in cancer therapies. We have previously shown that Ad E1B55K protein is involved in induction of cyclin E for Ad replication, but this E1B55K function is not required in cancer cells in which deregulation of cyclin E is frequently observed. In this study, we investigated the interaction of cyc...

Cyclin E/cyclin-dependent kinase 2 complexes are essential during the cell cycle for entrance into S phase. Cyclin E expression starts in mid-G1, reaches a maximum at S-phase entrance, and undergoes proteolysis mediated by the ubiquitin pathway as the cell progresses through S phase. Laser scanning cytometry, a microscope-based cytofluorometer combining the advantages of both flow and image ana...

Psoriasis is a hyperproliferative inflammatory skin disease; therefore, it is highly likely that psoriatic skin lesions may transform into malignancies. However, malignant transformation is not common. We performed immunohistochemical studies using anti‑cyclin D1, anti‑cyclin E, anti‑pRb, anti‑p53, anti‑p16INK4a, and anti‑Ki‑67 antibodies in normal skin, psoriatic epidermal tissue, and squamous...

Background: Zearalenone (ZEA) is known as a nonsteroidal oestrogenic mycotoxin produced by different species of Fusarium fungi. ZEA is known for its competitive effects with the natural 17-β estradiol to bind with the specific binding sites of the estrogen receptors (Ers). On the other hand, the cyclin family (especially cyclin D1) and E2F1 genes are the checkpoint genes involved in cell cycle....

Cyclin E and the retinoblastoma protein (Rb) are both important regulators of the G1 phase in the cell cycle. Overexpression of cyclin E and lost expression of Rb has previously been observed in breast tumours at frequencies of 10-50% and 20-30%, respectively. We explored the prognostic role of cyclin E and Rb in breast cancer patients randomised for tamoxifen (TAM), CMF (cyclophosphamide, meto...

Cyclin E supports pre-replication complex (pre-RC) assembly, while cyclin A-associated kinase activates DNA synthesis. We show that cyclin E, but not A, is mounted upon the nuclear matrix in sub-nuclear foci in differentiated vertebrate cells, but not in undifferentiated cells or cancer cells. In murine embryonic stem cells, Xenopus embryos and human urothelial cells, cyclin E is recruited to t...