Enhanced expression of the type II transforming growth factor-beta receptor is associated with decreased survival in human pancreatic cancer.

Transforming growth factor-betas (TGF-betas) bind to the type II TGF-beta receptor (TbetaRII), which then heterodimerizes with the type I TGF-beta receptor (TbetaRI), thereby initiating a signaling cascade. TGF-betas are overexpressed in pancreatic cancer, and this overexpression is associated with more aggressive disease. Although TbetaRII also is overexpressed in pancreatic ductal adenocarcinoma cells in vivo, the biologic significance of this overexpression is not completely known. Therefore in this study, we characterized TbetaRII expression by Northern blot analysis in 32 normal and 42 cancerous pancreatic tissues and correlated the survival of the cancer patients with TbetaRII messenger RNA (mRNA) levels. Northern blot analysis revealed that, by comparison with the normal controls, TbetaRII expression was increased in 19 (45%) of 42 cancer samples. Densitometric analysis of all the pancreatic tissues revealed a 3.4-fold increase (p < 0.01) in TbetaRII mRNA levels in the cancer tissues by comparison with normal controls. There was a strong correlation between the expression of TbetaRII and the levels of two invasion-promoting genes, plasminogen-activator-inhibitor-1 (PAI-1) and matrix-metalloproteinase-9 (MMP9). Log-rank analysis of the Kaplan-Meier survival curves indicated that patients whose tumors overexpressed TbetaRII had a significantly shorter survival period than did patients whose cancers expressed low levels of TbetaRII. It is suggested that TbetaRII overexpression may be a marker that correlates with disease progression in pancreatic ductal adenocarcinoma.