Researchers in Italy say a virus normally found in goats could offer a new, safer way to kill malignant mesothelioma cells and improve patient outcomes.
The virus is caprine herpesvirus 1 (CpHV-1). It has been blamed for bouts of spontaneous abortions in goat herds. But it does not appear to cause any disease in humans. In fact, previous studies show CpHV-1 can kill several types of human cancer cells.
The newest study of CpHV-1 was conducted at the National Cancer Institute IRCCS G. Pascale Foundation in Naples. Scientists there made two important discoveries. They found that not only can CpHV-1 kill mesothelioma cells without harming normal cells, but it might also have the potential to make chemotherapy work better.
Mesothelioma Cells are Tenacious
Mesothelioma is a rare cancer caused by asbestos. Mesothelioma cells spread quickly, forming tumors on the membranes around organs. As tumors grow, they crowd the nearby organs.
Mesothelioma tumors on the membrane around the lungs trigger coughing, chest pain, and shortness of breath. Mesothelioma tumors on the peritoneal membrane in the abdomen cause digestive issues, bloating, and stomach pain. Eventually, mesothelioma may spread to other tissues.
Malignant mesothelioma is also difficult to kill. It is usually not diagnosed until it is in a late stage. In addition, mesothelioma tumors release proteins that make the microenvironment around them hostile to cancer-killing immune cells. Most standard cancer treatments do not work on mesothelioma cells.
New approaches to mesothelioma treatment focus on killing these aggressive tumors from the inside. Immunotherapy and virotherapy fall into this category.
Attacking Mesothelioma with Virotherapy
Virotherapy uses a virus to deliver a treatment. Sometimes, it is an altered human virus. In the case of the new Italian study, it is the goat virus CpHV-1.
The researchers say some kinds of animal viruses offer advantages over human viruses for cancer treatment. They are less likely to be pathogenic (disease-causing) in humans. Also, human cells are not already immune to them.
When Italian researchers exposed mesothelioma cells and normal cells from the mesothelial membrane to CpHV-1, the results were exciting.
“We found that CpHV-1 reduced cell viability and clonogenic potential in all malignant mesothelioma cell lines without affecting non-tumor cells,” writes lead author Iris Maria Forte.
The researchers did not detect any viral DNA inside the healthy cells after treatment. But the virus sped up the rate of apoptosis or natural cell death in mesothelioma cells. The news gets even better.
“CpHV-1 strongly synergized with cisplatin, the drug currently used in mesothelioma chemotherapy, and this agent combination did not affect normal mesothelial cells,” writes Dr. Forte.
Scientists will need to study CpHV-1 more to understand how it works against mesothelioma. But the Italian researchers conclude that the CpHV-1/cisplatin combination “could be a feasible strategy against mesothelioma.”
Even though many countries have banned asbestos, tens of thousands of people around the world still contract mesothelioma every year.
Forte, IM, et al, “The Oncolytic Caprine Herpesvirus 1 (CpHV-1) Induces Apoptosis and Synergizes with Cisplatin in Mesothelioma Cell Lines: A New Potential Virotherapy Approach”, December 8, 2021, Viruses, https://www.mdpi.com/1999-4915/13/12/2458