title: [Role of endoplasmic reticulum protein folding molecular chaperones in floxuridine-resistance choriocarcinoma JeG-3/FUDRA cell line].
abstract: OBJECTIVE
  To investigate changes of protein expression profiles between human choriocarcinoma JeG-3 cell line and its floxuridine (FUDR)-resistant sub-line.
  
  
  METHODS
  The differentially expressed proteins were identified by using two dimension difference gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) approaches. Gene ontology (GO) analysis and Pathway analysis were used to screen the candidate proteins. The levels of the proteins in chemo-resistant sub-lines were validated by western blot. Ribonucleic acid interference (RNAi) was used to knockdown the expression of calreticulin (CALR) and (or) protein disulfide-isomerase A3 (PDIA3) respectively.
  
  
  RESULTS
  Forty-six proteins spots were found to be significantly different in spot intensity by statistical analysis between chemo-resistance sub-line and parent cell line, of which 31 proteins were identified by MALDI-TOF-MS. Comparing to the parent cell lines, three endoplasmic reticulum (ER) protein folding molecular chaperones: CALR, PDIA3 and 78 000 glucose-regulated protein (GRP78) screened out were increased significantly in floxuridine-resistant sub-line and were verified by western blot. The resistance index decreased by knockdown the CALR and/or PDIA3 expression in FUDR-resistant sub-line 76.3% (36.7 ± 2.0 vs. 8.7 ± 3.1, P < 0.05) and 51.4% (36.7 ± 2.0 vs. 17.8 ± 1.2, P < 0.05) respectively.
  
  
  CONCLUSIONS
  These ER protein folding molecular chaperones, CALR, PDIA3 and GRP78, may involved in the mechanism of FUDR-resistance choriocarcinoma.
authors.affiliation: Department of Obstetrics and Gynecology, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Han
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiang
authors.forename: Feng-zhi
authors.initials: FZ
authors.lastname: Feng
authors.forename: Xi-run
authors.initials: XR
authors.lastname: Wan
authors.forename: Hai-li
authors.initials: HL
authors.lastname: Qian
authors.forename: Xue-yan
authors.initials: XY
authors.lastname: Zhang
authors.forename: Xi-ting
authors.initials: XT
authors.lastname: Meng
authors.forename: Chen
authors.initials: C
authors.lastname: Lin
mesh_terms: D037282:Calreticulin / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002822:Choriocarcinoma / Q000378:metabolism* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D000091342:Endoplasmic Reticulum Chaperone BiP; D005260:Female; D005467:Floxuridine / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D040901:Proteomics / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D057825:Two-Dimensional Difference Gel Electrophoresis
chemical_list: D037282:Calreticulin; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D005467:Floxuridine; D019704:Protein Disulfide-Isomerases; C085868:PDIA3 protein, human