The number of liver cancer deaths in Japan peaked in the early 2000s and is declining.On the other hand, it is the second leading cause of death among all cancer types in the world.Liver cancer has a high probability of recurrence after surgery to remove the tumor and is known to have an extremely poor prognosis.Peretinoin has the effect of reducing the risk of recurrence to 2% or less by selectively killing liver cancer cells, and is being clinically tested as the world's first preventive measure against liver cancer recurrence.Peretinoin has been shown to have no effect on normal cells and selectively kill liver cancer cells.Kojima Unit Leaders and colleagues have discovered in previous studies that peretinoin has the ability to collect a protein called TG20 around the cell nucleus.This suppressed the expression of genes essential for the survival of cancer cells.However, the details of its function were not well understood.

　In this study, we investigated which parts play an important role in gathering inside the nucleus by suppressing the functions of each of the four components that make up TG2 by recombining genes.As a result, we found that one component was needed to get inside the nucleus.This is because it binds to substances that carry proteins into the nucleus.And peretinoin played a role in promoting these bonds.

　It has become clear that the migration of TG2 into the nucleus by peretinoin is the cause of the death of liver cancer cells.In the future, if we can discover substances that cause TG2 migration more efficiently than peretinoin, it may lead to the development of more effective recurrence preventive drugs.