Researchers mainly from Kyoto University have found that the impaired function of a specific gene contributes to the malignancy of pancreatic cancer, which is hard to treat with chemotherapy.

They said the reduced gene function increases a protein that promotes metastasis and that existing drugs may be effective in suppressing the protein¡¯s functions. The finding was published in the Journal of Clinical Investigation in June.

Pancreatic cancer is the third-leading cause of cancer death in Japan. The five-year survival rate for the cancer is 8.5%, the worst among any cancer.

Malignant cases account for 30% to 40%, but the underlying mechanisms had not been well understood.

The team examined pancreatic cancer tissue removed during surgery and found that the decline in function of Polybromo 1 ¡ª or PBRM1, a gene that regulates the expression of various proteins ¡ª is linked to greater malignancy and a higher risk of relapse.

A genetic modification to disable PBRM1 in mice with pancreatic cancer resulted in a higher malignancy rate, increased metastases and shorter survival.

The cancer cells showed an increased level of vimentin, a protein that promotes metastasis. Meanwhile, the malignancy rate and metastases decreased after mice were given a drug that suppresses vimentin.

Such correlations were also confirmed in human pancreatic cancer.

The research ¡°has shown that drugs to suppress vimentin effects may lead to a new treatment for highly malignant pancreatic cancer,¡± Kyoto University associate professor Akihisa Fukuda said. ¡°We hope to conduct clinical trials to realize early practical application.¡±