They found that when engineered on virus-like particles, mesothelin lowered tumour growth in mice. "The protein called mesothelin appears to play an important role in promoting pancreatic cancer growth," said the senior author Dr. Qizhi (Cathy) Yao, professor of vascular surgery at BCM. For the study, mice having pancreatic cancer were injected three times with the vaccine of virus-like particles (VLPs) that contained mesothelin.
VLPs have a unique property of inducing protective immune responses but they lack the infectious capacities of the original virus.
The findings revealed that the tumour growth in the immunized mice slowed and in some cases the tumour disappeared.
The average life span for the mice increased to five weeks longer than those not treated.
The immunization suppressed the production of key immune system cells that restrain the body's ability to fight the tumour and pancreatic cancers produce these cells, called T regulatory cells, as a protective measure.
"If we are able to see the same results in humans, this would allow us to incorporate a combination therapy to treat the tumour. Treatment with a single drug is not effective," said Yao.
The study appears in journal Molecular Cancer Therapeutics.