The combined expression of CD34 and bcl-2 suggests that fibroadenomas, phyllodes tumours and pseudoangiomatous hyperplasia may arise from long-lived bcl-2-positive mesenchymal cells in the breast in a manner similar to that proposed for solitary fibrous tumours. The absence of CD34 staining in spindle cell carcinomas is of potential diagnostic value in the distinction from malignant phyllodes tumours in difficult cases.

Objectives Trefoil factor 1 (TFF1) is a stable secretory protein expressed widely in the gastrointestinal mucosa that is also expressed in pancreatic ductal adenocarcinoma (PDAC). In the current study, we documented the extent and timing of TFF1 expression and investigated the effects of TFF1 on PDAC cells and stellate cells, the primary cells of the PDAC stroma. Methods Trefoil factor 1 expression in pancreatic cancer tissues and cell lines was analyzed using microarray, quantitative reverse transcriptase–polymerase chain reaction, and immunohistochemistry. The effects of recombinant TFF1 on cell growth, migration, and invasion of pancreatic cancer cell lines and immortalized human pancreatic stellate cells (HPSCs) were analyzed using MTS and Matrigel-coated invasion chambers. In vivo studies were also conducted in which Mpanc-96 cells stably expressing TFF1 were implanted orthotopically into nude mice. Results Trefoil factor 1 was highly increased in preneoplastic lesions. Recombinant TFF1 stimulated motility of both cancer and HPSCs. In contrast, only HPSC cell growth was increased by TFF1. In vivo studies showed that overexpression of TFF1 in PDAC cells did not affect primary tumor growth but greatly increased metastasis. Conclusions The present data demonstrate that TFF1 influences both PDAC cells and stellate cells and stimulates metastasis.