The effect of roscovitine on herpetic keratitis

Roscovitine in cancer and other diseases

Roscovitine [CY-202, (R)-Roscovitine, Seliciclib] is a small molecule that inhibits cyclin-dependent kinases (CDKs) through direct competition at the ATP-binding site. It is a broad-range purine inhibitor, which inhibits CDK1, CDK2, CDK5 and CDK7, but is a poor inhibitor for CDK4 and CDK6. Roscovitine is widely used as a biological tool in cell cycle, cancer, apoptosis and neurobiology studies. Moreover, it is currently evaluated as a potential drug to treat cancers, neurodegenerative diseases, inflammation, viral infections, polycystic kidney disease and glomerulonephritis. This review focuses on the use of roscovitine in the disease model as well as clinical model research.

Agents and strategies in development for improved management of herpes simplex virus infection and disease

The quiet pandemic of herpes simplex virus (HSV) infections has plagued humanity since ancient times, causing mucocutaneous infection such as herpes labialis and herpes genitalis. Disease symptoms often interfere with every-day activities and occasionally HSV infections are the cause of life-threatening or sight-impairing disease, especially in neonates and the immuno-compromised patient population. After infection the virus persists for life in neurons of the host in a latent form, periodically reactivating and often resulting in significant psychosocial distress for the patient. Currently no cure is available. So far, vaccines, ILs, IFNs, therapeutic proteins, antibodies, immunomodulators and small-molecule drugs with specific or non-specific modes of action lacked either efficacy or the required safety profile to replace the nucleosidic drugs acyclovir, valacyclovir, penciclovir and famciclovir as the first choice of treatment. The recently discovered inhibitors of the HSV helicase-primase are the most potent development candidates today. These antiviral agents act by a novel mechanism of action and display low resistance rates in vitro and superior efficacy in animal models. This review summarises the current therapeutic options, discusses the potential of preclinical or investigational drugs and provides an up-to-date interpretation of the challenge to establish novel treatments for herpes simplex disease.

Roscovitine, a cyclin-dependent kinase inhibitor, prevents replication of varicella-zoster virus

Understanding the interactions between varicella-zoster virus (VZV) and host cells can be addressed by using small molecule inhibitors of cellular enzymes. Roscovitine (Rosco) is a purine derivative that inhibits cyclin-dependent kinase 1 (cdk1), cdk2, cdk5, cdk7, and cdk9, which are key regulators of the cell cycle and transcription. Herpesviruses are known to interact with cell cycle proteins; thus, the antiviral effects of Rosco on VZV growth were evaluated. In a plaque reduction assay, 25 micro M Rosco prevented VZV replication, and the antiviral effect was reversible for at least up to 24 h posttreatment. Rosco also reduced expression of the major transactivator, IE62, over 48 h. Confocal microscopy studies indicated that Rosco caused the immediate-early proteins ORF4 and IE62 to abnormally localize in infected cells and prevented cell-cell spread of VZV over 48 h. Rosco was found to inhibit VZV DNA synthesis as measured by real-time PCR, and this technique was used to estimate the 50% effective concentration (EC(50)) of 14 micro M. This value was close to the EC(50) estimate of 12 micro M determined from plaque reduction assays. At 25 micro M, Rosco was not cytotoxic over 48 h in a neutral red uptake assay, and proliferation was slowed as the cells accumulated in a G(2)-like state. These results demonstrate the importance of cdk's in VZV replication and suggest that cdk inhibitors could serve as useful VZV antivirals.