title: Expression of multidrug resistance-related markers in gastric cancer.
abstract: BACKGROUND
  To detect the expression of glutathione S-transferase Pi(GST-pi), multidrug resistance-associated protein (MRP), lung-resistance protein(LRP), multidrug resistance gene1 (MDR1) and MGr1 antigen(MGr1-Ag) in the patients with primary gastric cancer and without any prior chemotherapy and to evaluate the correlations between them.
  
  
  METHODS
  The expression of GST-pi, MRP, LRP and MDR1 in cancer tissue and the adjacent non-cancerous tissue from 50 patients was examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The expression of MGr1-Ag in these tissues was also examined by immunohistochemistry.
  
  
  RESULTS
  The positive rate of GST-pi mRNA, MRP mRNA, LRP mRNA, MDR1mRNA and MGr1-Ag in gastric cancer tissue was 36.00%, 12.00%, 10.00%, 10.00% and 18.00% respectively. The overall positive rate of their expression was 58.00%. Clinicopathological factors were not significantly related to their expression. No significant correlation was observed between these markers.
  
  
  CONCLUSIONS
  These MDR markers are differently over-expressed and no coexpression exists in gastric cancer. MGr1-Ag was a novel MDR protein.
authors.affiliation: Department of Gastroenterology, Great Wall Hospital, Beijing, 100853, People's Republic of China.
authors.forename: K
authors.initials: K
authors.lastname: Fan
authors.forename: D
authors.initials: D
authors.lastname: Fan
authors.forename: L F
authors.initials: LF
authors.lastname: Cheng
authors.forename: C
authors.initials: C
authors.lastname: Li
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis / Q000235:genetics; D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D017931:DNA Primers; D018432:Drug Resistance, Multiple; D005260:Female; D005982:Glutathione Transferase / Q000032:analysis / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D014158:Transcription, Genetic; D020394:Vault Ribonucleoprotein Particles / Q000235:genetics; D000099187:Major Vault Protein
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D017931:DNA Primers; D005982:Glutathione Transferase; D009363:Neoplasm Proteins; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein