TS and DPD expression levels were higher in tumor tissues, and TS expression levels were significantly lower in adenocarcinomas than those in other subtypes.
In this study, we sought to analyze the prognostic value of p21-activated kinase 1 (PAK1), p21-activated kinase 4 (PAK4), human equilibrative nucleoside transporter 1 (hENT1), and thymidylate synthase (TS) in surgically resected pancreatic ductal adenocarcinomas.
Evaluating the Prognostic Value of ERCC1 and Thymidylate Synthase Expression and the Epidermal Growth Factor Receptor Mutation Status in Adenocarcinoma Non-Small-Cell Lung Cancer.
In this study, we showed that erlotinib (1.25-10μM) treatment down-regulating of TS expression in an AKT inactivation manner in two NSCLC cell lines, human lung squamous cell carcinoma H1703 and adenocarcinoma H1975 cells.
We hypothesized associations of the biomarkers excision repair cross-complementing 1 (ERCC1), ribonucleotide reductase M1 (RRM1), and thymidylate synthase (TS) with histology as a contributing factor to reported differences in chemotherapy outcomes between squamous cell carcinoma (SCCA) and adenocarcinoma (AC) subtypes.
Using immunohistochemistry to evaluate thymidylate synthase protein levels, we found that the expression of thymidylate synthase in these mixed tumors roughly parallel that of squamous cell carcinoma, instead of falling in between squamous cell and adenocarcinoma.
FRα expression was correlated with thymidylate synthase and p53 expression in NSCLCs, and with epidermal growth factor receptor (EGFR) and V-Ki-ras2 Kirsten rat sarcoma viral (KRAS) gene mutations in adenocarcinomas.
Analyses of TS gene expression levels in primary tumor according to histologic cell type revealed that small-cell carcinoma showed highest TS expression (mean TS/β-actin, 13.8) and that squamous cell carcinoma showed higher TS expression as compared with adenocarcinoma (mean TS/β-actin, 4.3 and 2.3, respectively; P < 0.01); TS gene expression was significantly increased along with a decrease in the grade of tumor cell differentiation.
In patients with adenocarcinoma, the low TS patient group also had a longer median PFS and a longer median overall survival (OS) as compared with patients with high TS expression (PFS, 4.8 vs. 3.8 months, p=0.03; OS, 21.4 vs. 10.0 months, p=0.03).
Neuroendocrine carcinomas show characteristic patterns of expression for 5-FU-related enzymes, including low DPD mRNA and protein level and high TS mRNA level compared with adenocarcinomas.
Thymidylate synthase, the main molecular target of pemetrexed, has higher mRNA and protein expression in squamous- and small-cell lung cancer compared with adenocarcinoma.
It is noteworthy that TS expression was significantly higher in squamous cell carcinoma compared with adenocarcinoma when both mRNA levels (2.17 vs. 1.16; P < .0001) and protein levels (P = .0269) were considered in FFPE specimens, and a strong association was observed between mRNA and protein expression (P = .00017).
Although both TS and DPD activities showed a tendency to be high for adenocarcinoma, there was no significant difference between TS and/or DPD activities and any clinical findings (age, gender, stage and histological type).
Poorly and well differentiated adenocarcinomas of the colorectum showed the relative elevation of activities of thymidylate synthase and thymidine kinase, respectively.
We have previously shown that relative thymidylate synthase (TS) mRNA levels in primary gastric adenocarcinomas treated with fluorouracil (5-FU) and cisplatin are inversely associated with response and survival.
Mutation(s) of the thymidylate synthase gene of human adenocarcinoma cells causes a thymidylate synthase-negative phenotype that can be attenuated by exogenous folates.