Bmi1 inhibition enhances the sensitivity of pancreatic cancer cells to gemcitabine

Oncotarget. 2016 Jun 14;7(24):37192-37204. doi: 10.18632/oncotarget.9293.


As the standard therapy for pancreatic cancer, gemcitabine shows limited efficacy in pancreatic cancer patients because of chemoresistance. Aberrant expression of Bmi1 has been reported to activate multiple growth-regulatory pathways and confer anti-apoptotic abilities to many cancer cells. However, the role of Bmi1 in response of pancreatic cancer cells towards gemcitabine resistance remains elusive. In this study, we found that certain dose of gemcitabine treatment induced Bmi1 expression in pancreatic cancer cells. Knockdown of Bmi1 enhanced ROS production and promoted the cytotoxic effect of gemcitabine. The increased oxidative stress upon gemcitabine treatment could disrupt mitochondrial membrane and decrease mitochondrial membrane potential, eventually leading to apoptosis. Bmi1 inhibition also suppressed the activation of NF-κB signaling and the expressions of downstream molecules in pancreatic cancer cells treated with gemcitabine. Moreover, we observed Bmi1 inhibition sensitized the pancreatic xenograft tumors to gemcitabine in vivo. Taken together, our study demonstrated that Bmi1 could decrease the sensitivity of pancreatic cancer cells to gemcitabine through increasing oxidative stress and inhibiting NF-κB signaling, thus Bmi1 may serve as a promising target for sensitizing pancreatic cancer cells to chemotherapy.

Keywords: Bmi1; chemotherapy; efficacy; gemcitabine; pancreatic cancer.

MeSH terms

  • Animals
  • Antimetabolites, Antineoplastic / pharmacology*
  • Antimetabolites, Antineoplastic / therapeutic use
  • Apoptosis
  • Cell Line, Tumor
  • Deoxycytidine / analogs & derivatives*
  • Deoxycytidine / pharmacology
  • Deoxycytidine / therapeutic use
  • Down-Regulation
  • Drug Resistance, Neoplasm*
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescent Antibody Technique
  • Gemcitabine
  • Gene Knockdown Techniques
  • Humans
  • Intracellular Membranes / drug effects
  • Membrane Potential, Mitochondrial / drug effects
  • Mice, Nude
  • Mitochondria / drug effects
  • NF-kappa B / metabolism*
  • Oxidative Stress
  • Pancreas / pathology
  • Pancreatic Neoplasms / drug therapy*
  • Pancreatic Neoplasms / pathology
  • Polycomb Repressive Complex 1 / genetics
  • Polycomb Repressive Complex 1 / metabolism*
  • RNA, Small Interfering / genetics
  • Reactive Oxygen Species / metabolism
  • Signal Transduction
  • Treatment Outcome
  • Xenograft Model Antitumor Assays


  • Antimetabolites, Antineoplastic
  • BMI1 protein, human
  • NF-kappa B
  • RNA, Small Interfering
  • Reactive Oxygen Species
  • Deoxycytidine
  • Polycomb Repressive Complex 1
  • Gemcitabine