Amatori Federica, Di Paolo Antonello, Del Tacca Mario, Fontanini Gabriella, Vannozzi Francesca, Boldrini Laura, Bocci Guido, Lastella Marianna, Danesi Romano
Division of Pharmacology and Chemotherapy, Department of Internal Medicine, University of Pisa, Pisa, Italy.
Pharmacogenet Genomics. 2006 Nov;16(11):809-16. doi: 10.1097/01.fpc.0000230410.07899.bc.
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.
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.
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 TSER3G/3G (-0.35+/-0.35) with respect to pooled homozygous TSER2/2 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.
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.
比较胸苷酸合成酶（TS）、二氢嘧啶脱氢酶（DPD）和胸苷磷酸化酶（TP）基因多态性及在未经化疗的结直肠癌（CRC）患者和正常黏膜中的表达。
以甘油醛-3-磷酸脱氢酶作为看家基因，采用实时逆转录聚合酶链反应分析53例患者原发性CRC组织及癌旁正常组织中TS、DPD和TP的mRNA表达。通过聚合酶链反应和限制性片段长度多态性分析确定TS启动子（TSER和C/G单核苷酸多态性）和DPD第14内含子+1G>A基因型。此外，在Colo 320、HT-29、CaCo-2和SW620人CRC细胞系中评估TS、DPD和TP表达与5-氟尿嘧啶细胞毒性之间的相关性。
肿瘤组织和正常组织中TP和DPD的mRNA表达存在显著差异（分别为7.51±13.50对1.10±0.57，P<0.05；0.60±0.63对1.17±0.55，P<0.0001），而TS mRNA水平未观察到差异。高分化、未分化肿瘤（世界卫生组织3级）的TS mRNA水平相对于中分化（世界卫生组织2级）癌显著更高（分别为0.38±0.37对0.00±0.44；P<0.05）。值得注意的是，纯合TSER3G/3G基因型（-0.35±0.35）的TS mRNA表达相对于纯合TSER2/2和杂合TSER*2/3基因型（0.14±0.41）显著降低（P<0.05）。体外实验结果显示，TS表达最低的细胞系对5-FU的敏感性更高。
目前的结果表明，正常黏膜和肿瘤样本之间DPD和TP基因表达存在显著差异，而TSER*3G/3G和高分化组织学与肿瘤样本中TS基因表达的显著变化相关。
