Virus Helps in Fight against Cancer

reovirus outer capsid proteinReoviruses (Respiratory Enteric Orphan virus) are found in sewage and water supplies and, although infection in humans is quite common, most cases do not cause any clinical symptoms and go unnoticed. Over a decade ago, it was discovered that, whilst reoviruses are harmless to normal cells, they selectively kill cancer cells that have a constitutively activated Ras pathway. It is thought that the cycle of infection, replication and cell death is repeated until no cells with an activated Ras pathway remain. Cells with an activated Ras pathway are unable to mount a normal antiviral response mediated by the double-stranded RNA activated protein kinase, PKR. Activating mutations of Ras and mutations along the Ras pathway occur in approximately two-thirds of all tumours.

Now the Canadian company, Oncolytics, have announced that they intend to start a phase II/III study examining the effects of REOLYSIN®, the company’s proprietary formulation of the human reovirus, in combination with paclitaxel/carboplatin in refractory patients with head and neck cancers. In earlier studies, eight out of nine head and neck patients reported on to date had either a partial response or stabilization of disease, a response that exceeds the current standard of care treatment for this patient group. In a separate study, REOLYSIN® was found to be well tolerated and show promise for the treatment of bone/soft tissue sarcoma metastatic to the lung.

Childhood Asthma Linked to Common Cold

rsvThe prevalence of asthma is increasing, with up to one in four urban children now affected. Episodes may be triggered by environmental factors, exertion, emotional stress or infection. A recent study by research workers at the University of Texas Southwestern Medical Center, which is available in the Nov 15 issue of the Journal of Infectious Diseases, suggests that infection with respiratory syncytial virus (RSV) may lead to recurrent wheezing, even after the acute symptoms of infection have resolved. The study, which was carried out in mice, showed a striking correlation between the amount of virus detected in the lungs of the mice with the severity of airway hyper-reactivity. The group had previously shown that mice infected with RSV were more likely to develop chronic lung disease than uninfected mice. They also found that treatment of the infected mice with an anti-RSV antibody reduced the amount of virus in the lungs as well as the extent of hyper-reactivity and inflammation in the lungs.

Almost all children have had at least one RSV infection by the age of three, and a study is currently underway to determine whether treating children with an antibody against RSV can prevent wheezing during a one year follow-up period. The findings could lead to the development of treatments for children with recurrent wheezing caused by RSV infection.