5-6-7-8-tetrahydrofolic-acid and Colorectal-Neoplasms

Calcium folinate (leucovorin), which is converted in vivo into biologically active folate, enhances the potency of 5-fluorouracil (5-FU)-based chemotherapy in colorectal cancer. A common dosage of leucovorin in adjuvant and palliative settings is 60 mg/m(2). The aim was to determine the levels of tetrahydrofolate (THF), 5,10-methylenetetrahydrofolate (methyleneTHF), and 5-methyltetrahydrofolate (methylTHF) in tumour and mucosa of colorectal cancer patients who received different dosages of leucovorin intravenously at time of surgery.. Eighty patients scheduled for colorectal resection with indication of colorectal cancer were randomised into four groups to receive leucovorin at 0, 60, 200, or 500 mg/m(2), respectively. Blood samples were taken 10 and 30 min after leucovorin administration. Biopsy samples from tumour and mucosa were collected and snap-frozen at surgery. The levels of THF, methyleneTHF, and methylTHF in tumour and mucosa were assessed by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-MS/MS) and the results were related to clinical diagnosis and therapeutic regimens.. The folate levels in tissue revealed extensive inter-individual variability. The mean methyleneTHF value for the four treatment groups were 880, 1,769, 3,024 and 3,723 pmol/gww. Only half of the patients who received 60 mg/m(2) leucovorin had higher levels of methyleneTHF in tumour than patients who received 0 mg/m(2) leucovorin. Rectal cancer patients had significantly lower levels of methyleneTHF compared with colon cancer patients.. There was a large inter-patient variability of tissue folate levels in colorectal cancer patients after supplementation with leucovorin at standardised dosage. High leucovorin doses were needed to exceed baseline methyleneTHF values, especially in rectal cancer patients. The results indicate that the standardised leucovorin dose may be insufficient to attain the full antitumour effect of 5-FU. Further studies are needed to establish whether higher dosage yields a better treatment response.

Topics: Adult; Aged; Aged, 80 and over; Chromatography, Liquid; Colorectal Neoplasms; Dose-Response Relationship, Drug; Female; Humans; Leucovorin; Male; Middle Aged; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Tetrahydrofolates; Vitamin B Complex

Protein/nucleic acid deglycase DJ‑1 (DJ‑1) is a 20‑kDa conserved protein, which belongs to the DJ‑1/ThiJ/Pfp Ⅰ protein superfamily. Immunohistochemistry was performed to investigate the expression of DJ‑1 in a colorectal cancer (CRC) tissue microarray containing tumor and corresponding adjacent normal tissues. In the present study, DJ‑1 expression was significantly upregulated in CRC cells and tissues, compared with that in normal colon cells and adjacent normal tissues, respectively. In addition, patients with high DJ‑1 expression levels had a worse overall survival (OS) compared with patients with low expression levels. Multivariate Cox regression analysis revealed that high DJ‑1 expression levels was an independent prognostic factor for patients with CRC. Moreover, DJ‑1 was able to regulate the PI3K/Akt/p27/cyclin E and PI3K/Akt/mTOR signaling pathways to promote CRC cell growth and metastasis in vitro and in vivo. In addition, DJ‑1 regulated the NF‑κB/Snail signaling pathway to induce CRC cell epithelial‑mesenchymal transition to promote migration and invasion. Notably, patients receiving LFP treatment (oxaliplatin, 5‑FU and tetrahydrofolate) had an increased OS compared with patients who underwent only surgery and low DJ‑1 expression levels. The findings from the present study suggest that DJ‑1 may serve as a promising prognostic marker and predicts chemotherapy efficacy in patients with CRC.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Cell Line, Tumor; Cell Movement; Cell Proliferation; Colorectal Neoplasms; Epithelial-Mesenchymal Transition; Female; Fluorouracil; Gene Expression Regulation, Neoplastic; HCT116 Cells; HT29 Cells; Humans; Male; Mice; Middle Aged; Neoplasm Metastasis; Oxaliplatin; Prognosis; Protein Deglycase DJ-1; Signal Transduction; Survival Analysis; Tetrahydrofolates; Up-Regulation; Xenograft Model Antitumor Assays

Folate and related gene variants are significant risk factors in the aetiology of colorectal cancer. Dihydrofolate reductase (DHFR) is critical in the metabolism of synthetic folic acid (pteroylmonoglutamatamic, PteGlu) to tetrahydrofolate following absorption. Therefore, the 19bp deletion variant of DHFR may lead to the alteration of folate-related colorectal disease susceptibility. This study examined the association between PteGlu and 19bp del-DHFR, and adenomatous polyp (AP) occurrence, an antecedent of colorectal cancer. A total of 199 subjects (162 controls and 37 AP cases) were analysed to determine dietary intake of total folate, natural methylfolate and synthetic PteGlu, level of erythrocyte folate and plasma homocysteine (tHcy), and genotype of 19bp del-DHFR. Dietary folate intake, erythrocyte folate, tHcy and 19bp del-DHFR variants did not independently predict the occurrence of AP. However, a gene-nutrient interaction was observed when subjects were stratified according to dietary folate intake. In subjects with a folate intake above the median value due to significant dietary PteGlu content, the presence of the 19bp-deletion allele decreased the risk for AP (OR=0.35, 95% CI: 0.13-0.97). However, such association was not evident in individuals with a folate intake below the median value. In conclusion, the finding suggests that folate nutrition and 19bp del-DHFR variation may interact to modify AP risk.

Topics: Adenomatous Polyps; Aged; Alleles; Colorectal Neoplasms; Diet; Epigenesis, Genetic; Female; Folic Acid; Genotype; Humans; Male; Middle Aged; Nutritional Status; Polymorphism, Genetic; Risk Factors; Tetrahydrofolate Dehydrogenase; Tetrahydrofolates

In patients with colorectal cancer (CRC), modulation of 5-fluorouracil (5-FU) by folinic acid (FA) improves response rate and overall survival compared with 5-FU alone. However, the optimal dose of FA is still debated. We investigated reduced folate pools in various tissues from patients with CRC without and after prior administration of FA.. A total of 186 specimens (normal colorectal mucosa, primary colorectal tumor, normal liver, and liver metastases) from 86 consecutive patients with CRC were obtained and investigated for levels of reduced folates. Before surgery, patients did (n = 52) or did not (n = 34) receive FA as 15-minute i.v. infusion. FA-dose levels chosen were 20, 200, or 500 mg/m2. Tissue lysates were analyzed for reduced folate levels by means of the tritium release assay.. In normal mucosa, combined pools of tetrahydrofolate and 5,10-methylenetetra-hydrofolate were significantly elevated at all FA dose levels compared with untreated controls. In primary tumor, only 200 and 500 mg/m2 FA resulted in a significant increase of reduced folates with highest values measured after 500 mg/m2 FA. In specimens from normal liver, folate levels did not increase after administration of FA. By contrast, in specimens from liver metastases, reduced folate levels were low without FA pretreatment compared with levels from normal liver samples. Infusion of 500 mg/m2 FA caused a significant increase of reduced folate levels in liver metastases.. From a pharmacologic point of view, high-dose FA should be recommended for optimal modulation of 5-FU in patients with mCRC.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Fluorouracil; Humans; Leucovorin; Tetrahydrofolates

Aberrant DNA methylation occurs in a subset of colorectal cancers and is characterized by regional areas of hypermethylation at CpG islands. The aims of this study were firstly to evaluate the levels of folate intermediates (FIs) in tumors with aberrant DNA methylation and secondly to determine whether these levels are affected by polymorphisms in key genes involved in folate metabolism.. The concentrations of two major intracellular FIs, 5,10-methylenetetrahydrofolate and tetrahydrofolate (FH4), were measured in 103 surgically resected colorectal cancers. DNA hypermethylation at seven different CpG islands was measured using the MethylLight assay. Genotyping for polymorphisms in the thymidylate synthase, cystathionine beta-synthase, methionine synthase, and methylenetetrahydrofolate reductase (MTHFR) genes was carried out using PCR and PCR-RFLP.. Significantly higher levels of FH4 were found in tumors from the proximal colon compared with those originating in the distal colon and rectum. Tumors with aberrant DNA methylation of CpG islands within promoter regions of the hMLH1, TIMP3, and ARF genes also contained higher levels of both 5,10-methylenetetrahydrofolate and FH4. In contrast, patients who were homozygous for the C667T polymorphism of the MTHFR gene had significantly lower concentrations of both these FIs in their tumor tissue.. The concentrations of FIs in colorectal tumors are directly related to the presence of frequent DNA hypermethylation and inversely related to the presence of a common polymorphism in the MTHFR gene. FIs could serve as biochemical markers for the risk of developing this disease, as well as for the prediction of toxicity and efficacy of fluorouracil-based treatments.

Topics: 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; Adenocarcinoma; Adenoma; Aged; Colorectal Neoplasms; CpG Islands; Cystathionine beta-Synthase; DNA Methylation; Female; Genotype; Humans; Male; Methylenetetrahydrofolate Reductase (NADPH2); Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Tetrahydrofolates; Thymidylate Synthase

The in vitro stability and plasma pharmacokinetics of 5,10-methylenetetrahydrofolic acid (CH2FH4), tetrahydrofolic acid (FH4), 5-methyltetrahydrofolic acid (CH3FH4), and 5-formyltetrahydrofolic acid (5-CHOFH4) were studied in view of their potential usefulness in cancer chemotherapy. Analysis of reduced folates was done on a high-performance liquid chromatography (HPLC) system. The high sensitivity of FH4 and CH2FH4 to oxidation can be circumvented by use of high concentrations of the folates, addition of ascorbate, and by thorough exclusion of atmospheric O2. Intravenous injection of 200 mg FH4 or CH2FH4 resulted in average peak concentrations of 69.2 +/- 3.2 nmol/ml and 46.3 +/- 2.6 nmol/ml, respectively. The plasma concentration curves support the concept that these highly oxygen-sensitive reduced folates can be reliably administered as pharmaceuticals to cancer patients through the use of a suitable air-occlusive system for their preparation and administration.

Topics: Colorectal Neoplasms; Drug Stability; Female; Formyltetrahydrofolates; Humans; Male; Oxidation-Reduction; Tetrahydrofolates

Various factors, including thymidylate synthase, thymidine kinase, 5-fluorouracil phosphorylation and degradation pathways, folate concentrations, and the stability of ternary complex, which influence thymidylate synthase inhibition rate of fluoropyrimidines, were studied in 87 human adenocarcinoma tissues.. The activity of the 5-fluorouracil degradation pathway was not significantly lower than the activity of the 5-fluorouracil phosphorylation pathway. The activity of the catabolism pathway of 5-fluorouracil should be considered in human adenocarcinoma tissue during chemotherapy. On the other hand, the means plus or minus standard deviations (means +/- SD) of the concentration of 5,10-methylenetetrahydrofolate and tetrahydrofolate were 0.69 +/- 0.54 and 1.25 +/- 0.69 nM, respectively, for the adenocarcinoma tissues without previous chemotherapy.. Because the half-life of tritium-labeled ternary complex and folate concentration in cytosol were correlated well, the differences in folate concentration among tumors must influence the dynamic equilibrium of ternary complex formation. Moreover, these results show that the ratio of 5,10-methylenetetrahydrofolate concentration to thymidylate synthase concentration influences the thymidylate synthase inhibition rate in tumor, and that the new synthesis of 5,10-methylenetetrahydrofolate and tetrahydrofolate from other endogenous reduced folates is also important in tumors with high thymidylate synthase concentrations.

Topics: Adenocarcinoma; Colorectal Neoplasms; Culture Techniques; Fluorouracil; Folic Acid; Humans; Leucovorin; Lymph Nodes; Phosphorylation; Stomach Neoplasms; Tetrahydrofolates; Thymidine Kinase; Thymidylate Synthase