title: Genistein potentiates the antitumor effect of 5-Fluorouracil by inducing apoptosis and autophagy in human pancreatic cancer cells.
abstract: BACKGROUND
  Although 5-fluorouracil (5-FU)-based combination chemotherapy (i.e. FOLFIRINOX) has demonstrated effectiveness against pancreatic cancer, novel therapeutic strategies must be developed to increase the therapeutic window of these cytotoxic agents. Genistein is a soy-derived isoflavone with pleiotropic biological effects that can enhance the antitumor effect of chemotherapeutic agents.
  
  
  METHODS
  To understand how genistein potentiates the antitumor effects of 5-FU, we examined apoptosis and autophagy in MIA PaCa-2 human pancreatic cancer cells and their derived xenografts. Apoptosis was evaluated using DNA fragmentation assays, and western blots of poly(ADP ribose)polymerase and caspase-3. Meanwhile, autophagy was evaluated using western blots of microtubule-associated protein light chain 3 (LC3)-I/II, fluorescent microscopy observation of green fluorescent protein-LC3B puncta formation, and acidic vesicular organelle formation using acridine orange staining. Tumors from animal treatment studies were examined for apoptosis and autophagy using the TdT-mediated dUTP nick-end labeling assay and immunohistochemical staining of LC3B, respectively.
  
  
  RESULTS
  We observed that genistein increased 5-FU-induced cell death through increased apoptosis, as well as autophagy. The increased autophagy was accompanied by decreased B-cell lymphoma 2 (Bcl2) and increased beclin-1 protein levels. Animal treatment studies supported these observations. The combination of 5-FU and genistein significantly reduced final xenograft tumor volume when compared to 5-FU-alone by inducing apoptosis as well as autophagy.
  
  
  CONCLUSIONS
  Genistein can potentiate the antitumor effect of 5-FU by inducing apoptotic as well as autophagic cell death. These results demonstrate the potential of genistein as an adjuvant therapeutic agent against pancreatic cancer.
authors.affiliation: Department of Gastroenterology, Hepatology and Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A.
authors.forename: Rei
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A.
authors.forename: Ya'an
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A.
authors.forename: Xinqun
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A.
authors.forename: David
authors.initials: D
authors.lastname: Roife
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A. jbflemin@mdanderson.org.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Fleming
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004357:Drug Synergism; D005472:Fluorouracil / Q000008:administration & dosage / Q000494:pharmacology*; D019833:Genistein / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D019833:Genistein; D005472:Fluorouracil
keywords: 5-fluorouracil; Pancreatic ductal adenocarcinoma; apoptosis; autophagy; cell death; genistein