Role of thymidylate synthase and dihydropyrimidine dehydrogenase mRNA in intrahepatic cholangiocarcinoma

5-Fluorouracil metabolic pathway genes predict recurrence risk following adjuvant S-1 therapy: Results of an ancillary analysis from a phase III trial of resected biliary tract cancer (JCOG1202A1)

BACKGROUND

S-1, an oral fluoropyrimidine derivative, is standard adjuvant therapy for resected biliary tract cancer (BTC), based on the results of the JCOG1202, a phase III trial evaluating the survival benefit with adjuvant S-1 following curative resection for BTC compared to surgery alone. This multicenter ancillary study of the JCOG1202 aimed to evaluate the prognostic impact of the 5-fluorouracil (5-FU) metabolic pathway genes including thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD).

METHODS

The 5-FU metabolic pathway genes were measured in tumor cells from formalin-fixed paraffin-embedded resected specimens from 183 patients (surgery alone: n = 94; adjuvant S-1: n = 89). We randomly divided them into training (n = 96) and validation sets (n = 87) for evaluating the interaction between gene levels and RFS benefits in the treatment arm.

RESULTS

RFS benefits of adjuvant S-1 were observed in the low DPD (HR = 0.440 and 0.748, respectively in the training and validation sets) and the low TP groups (HR = 0.709 and 0.602, respectively). Clinicopathological characteristics were well balanced between low and high DPD populations. More advanced stage tumors were observed in high TP populations as compared to those in low TP populations (p = .0332).

CONCLUSION

The results suggest the RFS benefit of adjuvant S-1 in resected BTC patients with low DPD and low TP gene expressions.

Intrahepatic cholangiocarcinoma: Role of metabolism in pathogenesis, clinical diagnosis, and treatment

Recent studies demonstrated that metabolism plays an important role in the pathogenesis, clinical diagnosis, and treatment of intrahepatic cholangiocarcinoma (ICC). The mechanisms of several metabolic enzymes associated with ICC, including pyruvate kinase M2 (PKM2), thymidine synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), isocitric acid dehydrogenase 1/2 (IDH1/2), and cyclo-oxygenase-2 (COX-2), have been gradually clarified and hopefully transformed into clinical application in the future. Besides, ICC patients always have concomitant abnormal lipid metabolism, which has attracted the attention of clinicians and researchers. Metabolites in serum and bile have potential diagnostic utility, which has yet to be verified by prospective clinical research. ¹⁸F-FDG PET/CT based on metabolism presents application value in many aspects of ICC, such as diagnosis, staging, evaluation of therapeutic effect, and monitoring prognosis. In this article, we review the recent progress in the understanding of the role of metabolism in ICC from both basic and clinical perspectives, with an aim to highlight the further research directions and accelerate the clinical transformation.

Concept mapping One-Carbon Metabolism to model future ontologies for nutrient-gene-phenotype interactions

Advances in the development of bioinformatic tools continue to improve investigators' ability to interrogate, organize, and derive knowledge from large amounts of heterogeneous information. These tools often require advanced technical skills not possessed by life scientists. User-friendly, low-barrier-to-entry methods of visualizing nutrigenomics information are yet to be developed. We utilized concept mapping software from the Institute for Human and Machine Cognition to create a conceptual model of diet and health-related data that provides a foundation for future nutrigenomics ontologies describing published nutrient-gene/polymorphism-phenotype data. In this model, maps containing phenotype, nutrient, gene product, and genetic polymorphism interactions are visualized as triples of two concepts linked together by a linking phrase. These triples, or "knowledge propositions," contextualize aggregated data and information into easy-to-read knowledge maps. Maps of these triples enable visualization of genes spanning the One-Carbon Metabolism (OCM) pathway, their sequence variants, and multiple literature-mined associations including concepts relevant to nutrition, phenotypes, and health. The concept map development process documents the incongruity of information derived from pathway databases versus literature resources. This conceptual model highlights the importance of incorporating information about genes in upstream pathways that provide substrates, as well as downstream pathways that utilize products of the pathway under investigation, in this case OCM. Other genes and their polymorphisms, such as TCN2 and FUT2, although not directly involved in OCM, potentially alter OCM pathway functionality. These upstream gene products regulate substrates such as B12. Constellations of polymorphisms affecting the functionality of genes along OCM, together with substrate and cofactor availability, may impact resultant phenotypes. These conceptual maps provide a foundational framework for development of nutrient-gene/polymorphism-phenotype ontologies and systems visualization.

NK4 regulates 5-fluorouracil sensitivity in cholangiocarcinoma cells by modulating the intrinsic apoptosis pathway

The aim of the present study was to investigate the role of NK4, an antagonist for hepatocyte growth factor (HGF) and the Met receptor, in regulating the response of cholangiocarcinoma (CCA) cells to 5-fluorouracil (5-FU). We established the CCA cell line, HuCC-T1, to produce abundant NK4 (Hu-NK4). Cell proliferation, cell cycle distribution, apoptosis, 5-FU metabolism and intracellular signaling were examined. There were no significant differences in the mRNA levels of thymidylate synthase, thymidine phosphorylase and dihydropyrimidine dehydrogenase between the mock-transfected control Hu-Em cells and Hu-NK4 cells, suggesting that NK4 expression does not alter 5-FU metabolism. Moreover, cell cycle analysis showed that 5-FU treatment caused a decrease in the proportion of cells in the G2/M phase while NK4 gene expression had little effect on the cell cycle distribution. However, 5-FU-induced apoptosis was significantly increased in the Hu-NK4 cells when compared to that in the Hu-Em cells. Further investigation revealed that NK4 gene expression enhanced 5-FU-induced caspase-3 and caspase-9 activation, and that the apoptosis of cells was associated with modulation of expression of the Bcl-2 family members. Furthermore, western blot analysis revealed that both NK4 and 5-FU were inhibitors for HGF-induced phosphorylation of Met, but they may be independent factors. Collectively, these results suggest that following 5-FU treatment in CCA cell lines, NK4 was involved in apoptosis induction through the intrinsic mitochondrial pathway. This indicates that NK4 may be an important mediator of 5-FU-induced cell death. Moreover, downregulation of NK4 in response to 5-FU may represent an intrinsic mechanism of resistance to this anticancer drug.