title: Thymidylate synthase, dihydropyrimidine dehydrogenase and thymidine phosphorylase expression in colorectal cancer and normal mucosa in patients.
abstract: OBJECTIVE
  To compare thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and thymidine phosphorylase (TP) gene polymorphism and expression in colorectal cancer (CRC), and normal mucosa in chemotherapy-naïve patients.
  
  
  METHODS
  TS, DPD and TP mRNA expression was analysed by real-time reverse-transcription polymerase chain reaction in primary CRC and adjacent normal tissues from 53 patients with glyceraldehyde-3-phosphate dehydrogenase as housekeeping gene. TS promoter (TSER and C/G SNP) and DPD IVS14+1G>A genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism assays. Moreover, the correlation between TS, DPD and TP expression and cytotoxicity of 5-fluorouracil was evaluated in Colo 320, HT-29, CaCo-2 and SW620 human CRC cell lines.
  
  
  RESULTS
  TP and DPD mRNA expression was significantly different in tumour and normal tissue (7.51+/-13.50 vs. 1.10+/-0.57, P<0.05 and 0.60+/-0.63 vs. 1.17+/-0.55, P<0.0001, respectively), whereas no differences were observed in TS mRNA levels. High-grade, undifferentiated tumours (WHO grade 3) had significantly higher mRNA levels of TS with respect to moderately differentiated (WHO grade 2) carcinomas (0.38+/-0.37 vs. 0.00+/-0.44, respectively; P<0.05). Noteworthy, TS mRNA expression was significantly decreased (P<0.05) in homozygous TSER*3G/3G (-0.35+/-0.35) with respect to pooled homozygous TSER*2/2 and heterozygous TSER*2/3 genotypes (0.14+/-0.41). In-vitro results showed a higher sensitivity to 5-FU of cell lines with the lowest TS expression.
  
  
  CONCLUSIONS
  The present results demonstrated significant differences in DPD and TP gene expression between normal mucosa and tumour samples, while TSER*3G/3G and high-grade histology were associated with significant variation in TS gene expression in tumour samples.
authors.affiliation: Division of Pharmacology and Chemotherapy, Department of Internal Medicine, University of Pisa, Pisa, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Amatori
authors.forename: Antonello
authors.initials: A
authors.lastname: Di Paolo
authors.forename: Mario
authors.initials: M
authors.lastname: Del Tacca
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
authors.forename: Francesca
authors.initials: F
authors.lastname: Vannozzi
authors.forename: Laura
authors.initials: L
authors.lastname: Boldrini
authors.forename: Guido
authors.initials: G
authors.lastname: Bocci
authors.forename: Marianna
authors.initials: M
authors.lastname: Lastella
authors.forename: Romano
authors.initials: R
authors.lastname: Danesi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D018938:Caco-2 Cells; D000069287:Capecitabine; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism*; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000494:pharmacology; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005472:Fluorouracil / Q000031:analogs & derivatives / Q000494:pharmacology; D015870:Gene Expression; D019073:HT29 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D013939:Thymidine Phosphorylase / Q000235:genetics / Q000378:metabolism*; D013940:Thymidylate Synthase / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000069287:Capecitabine; D042943:Dihydrouracil Dehydrogenase (NADP); D013940:Thymidylate Synthase; D013939:Thymidine Phosphorylase; D005472:Fluorouracil