title: DJ-1, a novel biomarker and a selected target gene for overcoming chemoresistance in pancreatic cancer.
abstract: OBJECTIVE
  Aberrant expression of DJ-1 has been proven to be associated with tumorigenesis in many carcinomas. However, its role in pancreatic cancer is unknown. The aims of this study were to investigate whether the serum DJ-1 might be a potential biomarker for pancreatic cancer and to determine the biologic function of DJ-1 expression in gemcitabine-induced chemoresistance of pancreatic cancer.
  
  
  METHODS
  The serum level of DJ-1 was higher in 128 pancreatic cancer patients compared with 62 healthy controls by ELISA. To determine the effect of DJ-1 on pancreatic tumor chemoresistance, a siRNA-targeting DJ-1 was synthesized and a stably transfected cell line with DJ-1 over-expression was constructed. The mechanism of tumor chemoresistance was assessed by multiple methods, such as MTT assay, real-time PCR, Western blot and flow cytometry.
  
  
  RESULTS
  The serum level of DJ-1 was higher in pancreatic cancer patients than healthy controls, and it has the relationship with tumor differentiation in pancreatic cancer. Down-regulation of DJ-1 enhanced gemcitabine-induced apoptosis in three pancreatic cancer cell lines. On the contrary, over-expression of DJ-1 desensitized the MIA PaCa-2 to the induction of apoptosis by gemcitabine.
  
  
  CONCLUSIONS
  Our results suggest that the serum level of DJ-1 may be a potential biomarker for pancreatic cancer, and that DJ-1 plays critical roles in the pancreatic tumor chemoresistance, supporting the development of chemotherapeutic approaches targeting this oncogene.
authors.affiliation: Department of Surgery, Second Affiliated Hospital, College of Medicine, Cancer Institute of Zhejiang University, Zhejiang University, #88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Muxing
authors.initials: M
authors.lastname: Kang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Lu
authors.forename: Qingqu
authors.initials: Q
authors.lastname: Guo
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Xie
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood* / Q000235:genetics; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015513:Oncogene Proteins / Q000097:blood* / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology; D000071617:Protein Deglycase DJ-1; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D003841:Deoxycytidine; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1; D000093542:Gemcitabine