Fighting fire with fire: a patent for the combined application of oncolytic herpes viruses and antiangiogenic agents in the battle against human cancers.

Specific elimination of tumor cells by replication-competent viral vectors is mediated through active viral replication, spread in tumor tissue and direct cytopathic effects. In addition, immune responses are induced against virally infected tumor cells. Recently, oncolytic vectors were constructed with mutations in neurovirulence genes or DNA synthesis genes. Viral replication should only be restricted to malignant cells to prevent severe viral disease. These constructed vectors terminate cells by mechanisms different from standard anti-cancer therapies; they offer another treatment modality which can be used in combination with chemotherapy, radiotherapy and gene therapies with additive or synergistic effects. Combination therapies are usually necessary to control tumorigenic diseases. Inhibiting angiogenesis represents another new field in current anticancer treatment development. Combining an oncolytic virus with antiangiogenesis is able to potentiate both treatment effects compared to each treatment modality alone in both primary and advanced disease. This combination might be beneficial for cancer patients in the future. We have also outlined some relevant patents.

Role of the p68 subunit of human DNA polymerase alpha-primase in simian virus 40 DNA replication.

DNA polymerase alpha-primase (pol-prim) is a heterotetramer with DNA polymerase and primase activities. The polymerase (p180) and primase (p48 and p58) subunits synthesize primers and extend them, but the function of the remaining subunit (p68) is poorly understood. Genetic studies in yeast suggested an essential role for the p68 ortholog in early S phase prior to the hydroxyurea-sensitive step, possibly a regulatory role in initiation of DNA replication, but found no evidence for an essential function of p68 later in S phase. To investigate whether the human p68 subunit has an essential role in DNA replication, we examined the ability of a purified trimeric human pol-prim lacking p68 to initiate simian virus 40 DNA replication in vitro and to synthesize and elongate primers on single-stranded DNA in the presence of T antigen and replication protein A (RPA). Both activities of trimeric pol-prim were defective, but activity was recovered upon addition of separately purified p68. Phosphorylation of p68 by cyclin A-dependent protein kinase also inhibited both activities of pol-prim. The data strongly suggest that the p68 subunit is required for priming activity of pol-prim in the presence of RPA and T antigen, both during initiation at the origin and during lagging strand replication.