Retinoblastoma

Research from University of Pittsburgh, Department of Pharmacology provides new data about prostate cancer therapy

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"The honokiol-mediated cell cycle arrest was associated with a decrease in protein levels of cyclin D1, cyclin-dependent kinase 4 (Cdk4), Cdk6, and/or cyclin E and suppression of complex formation between cyclin D1 and Cdk4 as revealed by immunoprecipitation using anti-cyclin D1 antibody followed by immunoblotting for Cdk4 protein. The honokiol-treated PC-3 and LNCaP cells exhibited a marked decrease in the levels of total and phosphorylated retinoblastoma protein (Rb), which correlated with the suppression of transcriptional activity of E2F1. Exposure of PC-3 and LNCaP cells to honokiol resulted in the induction of p21 (PC-3 and LNCaP) and p53 protein expression (LNCaP). However, small interfering RNA (siRNA)-mediated knockdown of either p21 (PC-3 and LNCaP) or p53 (LNCaP) protein failed to confer any protection against honokiol-induced cell cycle arrest," wrote E.R. Hahm and colleagues, University of Pittsburgh, Department of Pharmacology.

The researchers concluded: "The honokiol treatment caused the generation of reactive oxygen species (ROS), and the cell cycle arrest caused by honokiol was partially but significantly attenuated in the presence of antioxidant N-acetylcysteinethe present study reveals that the honokiol-mediated G0-G1 phase cell cycle arrest in human prostate cancer cells is associated with the suppression of protein level/phosphorylation of Rb leading to inhibition of transcriptional activity of E2F1."

Hahm and colleagues published their study in Molecular Cancer Therapeutics (Honokiol causes G0-G1 phase cell cycle arrest in human prostate cancer cells in association with suppression of retinoblastoma protein level/phosphorylation and inhibition of E2F1 transcriptional activity. Molecular Cancer Therapeutics, 2007;6(10):2686-95).

For additional information, contact E.R. Hahm, University of Pittsburgh School of Medicine, Dept. of Pharmacology, Pittsburgh, Pennsylvania USA..

Publisher contact information for the journal Molecular Cancer Therapeutics is: American Association Cancer Research, 615 Chestnut St., 17TH Floor, Philadelphia, PA 19106-4404, USA.

Keywords: United States, Pittsburgh, Prostate Cancer Therapy, Drugs, Oncology, Ophthalmology, Pharmaceuticals, Pharmacology, Prostate Cancer, Prostatic Neoplasms, Retinoblastoma, Therapies, Therapy, Treatment.

This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2007, Biotech Business Week via NewsRx.com.