Notch1 contributes to chemoresistance to gemcitabine and serves as an unfavorable prognostic indicator in pancreatic cancer

Abstract

Background: Pancreatic cancer (PC) carries frequent chemoresistance and extremely dismal prognosis. The underlying mechanisms remain to be further elucidated. We here report the role of Notch1 in gemcitabine resistance and its prognostic significance in PC. Methods: A small interfering RNA (siRNA) specifically targeting Notch1 was transiently transfected into three PC cell lines (AsPC-1, BxPC-3, and MIA PaCa-2), followed by examination of chemosensitivity to gemcitabine. On the other hand, Notch1 expression was evaluated immunohistochemically and correlated with clinicopathological and prognostic variables. Results: Successful knockdown of Notch1 by specific siRNA induced increased chemosensitivity to gemcitabine in all three cell lines. Immunohistochemical staining revealed that Notch1 was highly expressed in PC tissues (54.8 %), in contrast to that in para-tumor tissues (16.4 %). In addition, Notch1 positivity was significantly correlated with early-term metastasis and shortened overall survival. Multivariate Cox regression identified Notch1 as an independent prognostic factor. Conclusions: Notch1 contributes to chemoresistance to gemcitabine, and serves as a significant indicator of unfavorable prognosis in PC. © 2013 Société Internationale de Chirurgie.