Clinical Research
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 14, 2006; 12(10): 1597-1602
Published online Mar 14, 2006. doi: 10.3748/wjg.v12.i10.1597
Effect of gemcitabine on the expression of apoptosis-related genes in human pancreatic cancer cells
Pei-Hong Jiang, Yoshiharu Motoo, Norio Sawabu, Toshinari Minamoto
Pei-Hong Jiang, Norio Sawabu, Department of Internal Medicine and Medical Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
Yoshiharu Motoo, Department of Medical Oncology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
Toshinari Minamoto, Division of Diagnostic Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Yoshiharu Motoo, MD, Department of Medical Oncology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan.
Telephone: +81-76-2188284 Fax: +81-76-2188283
Received: July 11, 2005
Revised: October 1, 2005
Accepted: November 18, 2005
Published online: March 14, 2006

AIM: To investigate the expression of genes involved in the gemcitabine-induced cytotoxicity in human pancreatic cancer cells.

METHODS: A human pancreatic cancer cell line, PANC-1, was cultured. 1 x 104 PANC-1 cells were plated in 96-well microtiter plates. After being incubated for 24 h, gemcitabine was added to the medium at concentrations ranging 2.5 -1 000 mg/L. The AlamarBlue dye method was used for cell growth analysis. DNA fragmentation was quantitatively assayed using a DNA fragmentation enzyme-linked immunosorbent assay (ELISA) kit. PAP and TP53INP1 mRNA expression was determined using the reverse transcription-polymerase chain reaction with semi-quantitative analysis. The expression of GSK-3β and phospho-GSK-3β proteins was examined with Western blot analysis.

RESULTS: The IC50 for the drug after a 48-h exposure to gemcitabine was 16 mg/L. The growth of PANC-1 cells was inhibited by gemcitabine in a concentration-dependent manner (P < 0.0001) and the cell growth was also inhibited throughout the time course (P < 0.0001). The DNA fragmentation rate in the gemcitabine-treated group at 48 h was 44.7 %, whereas it was 25.3 % in the untreated group. The PAP mRNA expression was decreased after being treated with gemcitabine, whereas the TP53INP1 mRNA was increased by the gemcitabine treatment. Western blot analysis showed that phospho- GSK-3βser9 was induced by the gemcitabine treatment.

CONCLUSION: Gemcitabine suppresses PANC-1 cell proliferation and induces apoptosis. Apoptosis is considered to be associated with the inhibition of PAP and GSK-3β, and the activation of TP53INP1 and pospho-GSK-3βser9.

Keywords: Gemcitabine, Pancreatitis-associated protein, TP53INP1, GSK-3β, PANC-1