title: Thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, orotate phosphoribosyltransferase mRNA expression in lung cancer metastatic lymph node samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration: a pilot study.
abstract: BACKGROUND
  Pyrimidine antimetabolites' target molecules thymidylate synthase (TS) and flopropyrimidine-metabolising enzymes such as dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and orotate phosphoribosyltransferase (OPRT) are known as biomarkers of 5-fluorouracil (5-FU) treatment. The purpose of this study was to evaluate the feasibility of mRNA expression analysis for TS, DPD, TP, and OPRT using metastatic lymph node samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in patients with non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  Metastatic lymph nodes from 20 patients with NSCLC diagnosed by EBUS-TBNA were analyzed. After pathological diagnosis, additional sections were made and confirmed the existence of tumor cells by hematoxylin and eosin staining. Tumor cells were extracted using laser-captured microdissection and the mRNA levels were measured by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) for each marker.
  
  
  RESULTS
  There were 17 mediastinal and 3 hilar lymph nodes. The histology included 13 cases of adenocarcinoma and 7 cases of squamous cell carcinoma. DPD and TP could be successfully analyzed in all samples and TS and OPRT could be measured in 18 samples. The median values of the relative TS, DPD, TP, and OPRT mRNA expression levels were 10.68, 6.23, 18.32, and 1.77, respectively.
  
  
  CONCLUSIONS
  TS, DPD, TP, and OPRT mRNA expression levels could be analyzed using metastatic lymph node samples obtained by EBUS-TBNA. The result of this pilot study may be applicable for further translational research for the treatment of locally advanced NSCLC.
authors.affiliation: Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakajima
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hiroshima
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Takehiko
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshino
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000556:secondary; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001999:Bronchoscopy; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000556:secondary; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000235:genetics; D005240:Feasibility Studies; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009962:Orotate Phosphoribosyltransferase / Q000235:genetics; D010865:Pilot Projects; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013939:Thymidine Phosphorylase / Q000235:genetics; D013940:Thymidylate Synthase / Q000235:genetics; D018084:Ultrasonography, Interventional
chemical_list: D012333:RNA, Messenger; D042943:Dihydrouracil Dehydrogenase (NADP); D013940:Thymidylate Synthase; D009962:Orotate Phosphoribosyltransferase; D013939:Thymidine Phosphorylase