OBJECTIVETo investigate the influence of thymidylate synthase (TS) gene polymorphisms on high-dose methotrexate (HD-MTX)-related toxicities in childhood acute lymphoblastic leukemia (ALL).

METHODSA total of 73 children who were diagnosed with ALL between March 2011 and March 2013 were included into this study. Genomic DNAs were extracted from their peripheral blood. And then the genotypes of TS 5'-UTR were determined by direct DNA sequencing after PCR. The toxicity response of 73 patients receiving HD-MTX chemotherapy were observed and recorded, and plasma MTX concentrations at 42-48 hours after chemotherapy were measured.

RESULTSThe main HD-MTX-related toxicities of 73 patients receiving HD-MTX chemotherapy were neutropenia, decreased hemoglobin level, thrombocytopenia, liver toxicity, mucosal damage, and gastrointestinal reactions. There were no significant differences in the incidence rate of HD-MTX-related toxicities between children with different TS 5'-UTR genotypes after chemotherapy (P>0.05). TS 5'-UTR genotype was not significantly correlated with plasma MTX concentrations at 42-48 hours after chemotherapy (P>0.05).

CONCLUSIONSTS gene polymorphisms have no influence on the incidence of HD-MTX-related toxicities in childhood ALL.

Antimetabolites, Antineoplastic ; adverse effects ; Child ; Child, Preschool ; Female ; Genotype ; Humans ; Infant ; Male ; Methotrexate ; adverse effects ; Polymorphism, Genetic ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; genetics ; Thymidylate Synthase ; genetics

PURPOSE: The main objective of this study was to evaluate the association between polymorphisms of the target genes of pemetrexed and clinical outcomes in non-small cell lung cancer (NSCLC) patients treated with pemetrexed. MATERIALS AND METHODS: We assessed polymorphisms at 8 sites in 4 genes [thymidylate synthase (TS), dihydrofolate reductase (DHFR; 1610, 680, 317, intron 1), methylenetetrahydrofolate reductase (MTHFR; 677, 1298), glycinamide ribonucleotide formyl transferase (GARFT; 2255)] associated with pemetrexed metabolism using polymerase chain reaction, gene scanning, and restriction fragment length polymorphism analysis in 90 patients with adenocarcinoma of the lung. RESULTS: Survival was significantly longer with pemetrexed in patients with TS 3RGCC/3RGCC or 3RGGC/3RGGC compared with the other groups (PFS; 5.2 months vs. 3.7 months, p=0.03: OS; 31.8 months vs. 18.5 months, p=0.001). Patients with DHFR 680CC experienced fatigue more frequently (50% vs. 8.6%, p=0.008). Polymorphisms of MTHFR and GARFT were not significantly associated with clinical outcomes of pemetrexed. CONCLUSION: The TS genotype was associated with survival and one DHFR polymorphism was associated with fatigue in NSCLC patients treated with pemetrexed. Further large prospective studies are required to identify other biomarkers that affect patients being treated with pemetrexed for adenocarcinoma of the lung.
Adenocarcinoma/*drug therapy/*genetics/mortality ; Adult ; Aged ; Aged, 80 and over ; Antimetabolites, Antineoplastic/pharmacology/*therapeutic use/toxicity ; Female ; Glutamates/pharmacology/*therapeutic use/toxicity ; Guanine/*analogs & derivatives/pharmacology/therapeutic use/toxicity ; Humans ; Lung Neoplasms/*drug therapy/*genetics/mortality ; Male ; Methylenetetrahydrofolate Reductase (NADPH2)/genetics ; Middle Aged ; Pharmacogenetics ; Phosphoribosylglycinamide Formyltransferase/genetics ; *Polymorphism, Single Nucleotide ; Tetrahydrofolate Dehydrogenase/genetics ; Thymidylate Synthase/genetics

OBJECTIVE: To analyze the impact of β-tubulin-III (TUBB3), thymidylate synthase (TS) and excision repair cross complementation group 1 (ERCC1) mRNA expression on chemoresponse and clinical outcome of patients with advanced gastric cancer treated with TXT/CDDP/FU (DCF) regimen chemotherapy. METHODS: The study population consisted of 48 patients with advanced gastric cancer. All patients were treated with DCF regimen palliative chemotherapy. The mRNA expressions of TUBB3, TS and ERCC1 of primary tumors were examined by multiplex branched-DNA liquid chip technology. RESULTS: The patients with low TUBB3 mRNA expression had higher response rate to chemotherapy than patients with high TUBB3 expression (P=0.011). There were no significant differences between response rate and TS or ERCC1 expression pattern. Median overall survival (OS) and median time to progression (TTP) were significantly longer in patients with low TUBB3 mRNA expression (P=0.002, P<0.001). TS or ERCC1 expression was not correlated with TTP and OS. In the combined analysis including TUBB3, TS and ERCC1, the patients with 0 or 1 high expression gene had better response rate, TTP and OS than the remaining patients (all P<0.001). Multivariate analysis revealed that ECOG (Eastern Cooperative Oncology Group)≥2 (HR=2.42, P=0.009) and TUBB3 (HR=2.34, P=0.036) mRNA expression significantly impacted on OS. CONCLUSION High TUBB3 mRNA expression is correlated with resistance to DCF regimen chemotherapy. TUBB3 might be a predictive and prognostic factor in patients with advanced gastric cancer treated with TXT-based chemotherapy. The combined evaluation of TUBB3, TS and ERCC1 expression can promote the individual treatment in advanced gastric cancer.
Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Biomarkers, Tumor ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Drug Resistance, Neoplasm ; Endonucleases ; genetics ; metabolism ; Humans ; RNA, Messenger ; genetics ; metabolism ; Stomach Neoplasms ; drug therapy ; genetics ; Thymidylate Synthase ; genetics ; metabolism ; Treatment Outcome ; Tubulin ; genetics ; metabolism

BACKGROUNDSeveral studies have evaluated the association between polymorphisms of thymidylate synthase (TS) and cancer risk in diverse populations but with conflicting results. By pooling the relatively small samples in each study, it is possible to evaluate the association using a meta-analysis.

METHODSA comprehensive search was conducted to identify all case-control studies on TS on a 28-bp tandem repeats in 5'untranslated region (5'UTR) and a 6-bp insertion (ins) and deletion (del) mutation in 3'UTR of the gene and cancer risk. Meta-analysis was conducted using a fixed and random effect model.

RESULTSOur meta-analysis on a total of 13 307 cancer cases and 18 226 control subjects from 37 published case-control studies showed no significant association between the risk of cancer and the 5'UTR 28-bp tandem repeats polymorphism (3R/3R vs. 2R/2R: OR = 1.06, 95%CI, 0.93 - 1.20) or the 3'UTR 6-bp ins/del polymorphism (del6/del6 vs. ins6/ins6: OR = 0.93, 95%CI, 0.81 - 1.08) with significant between-study heterogeneity. In the cancer type- and ethnic subgroup-stratification analyses, we did not find any association between TS polymorphisms and cancer risk either.

CONCLUSIONTS 5'UTR 28-bp tandem repeats and 3'UTR 6-bp ins/del polymorphisms may not be associated with cancer risk.

3' Untranslated Regions ; genetics ; 5' Untranslated Regions ; genetics ; Case-Control Studies ; Genetic Predisposition to Disease ; genetics ; Humans ; Neoplasms ; epidemiology ; genetics ; Polymorphism, Genetic ; genetics ; Tandem Repeat Sequences ; genetics ; Thymidylate Synthase ; genetics

OBJECTIVETo investigate the effect of the RNAi and the chemotherapy drugs nolatrxed on the expression of thymidylate synthase(TS) and the growth of the colorectal carcinoma LOVO cells.

METHODSThe siRNA was constructed targeting the human TS gene, and then transfected into the human colorectal cancer LOVO cells. RT-PCR and Western blot technique were used to observe the TS gene and protein expression levels, and MTT was used to detect cell proliferation after silencing the TS gene. In addition, siRNA and nolatrxed were applied to the LOVO cells to observe the TS protein expression and cell growth.

RESULTSTS siRNA significantly reduced the expression of TS gene and protein in LOVO cells, and inhibited cell growth. The IC50 value of LOVO cells was (1.46±0.25) μmol/L in TS siRNA combined with nolatrexed group, (6.81±0.31) μmol/L in the negative control group, and (6.47±0.43) μmol/L in the single nolatrexed group. After treatment of TS siRNA combined with nolatrexed on LOVO cells for 36 hours, the apoptosis index was higher than that in single TS siRNA and nolatrexed[(62.12±0.89)% vs.(21.56±0.67)% and(40.51±0.83)%, both P<0.05].

CONCLUSIONTS siRNA can partly suppress the expression of TS gene in LOVO cells, inhibit cell proliferation, promote cell apoptosis and enhance cell sensitivity to apoptosis induced by nolatrexd.

Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; enzymology ; pathology ; Humans ; Quinazolines ; pharmacology ; RNA Interference ; Thymidylate Synthase ; genetics ; metabolism

BACKGROUNDThymidylate synthase (TS) is a key regulatory enzyme for de novo DNA synthesis. TS activity is also an important determinant of the response to chemotherapy with fluoropyrimidine prodrugs, and its expression may be affected by gene polymorphisms. In this study, we investigated the associations between polymorphisms of the TS gene and its protein expression, and the implications on the efficacy of 5-fluorouracil (5-FU) in pancreatic cancer cells.

METHODSGenotypes based on the 28-bp TS tandem repeat for pancreatic cell lines were determined by electrophoretic analysis of PCR products. A single nucleotide polymorphism (SNP) at nucleotide 12 of the second 28-bp repeat of the 3R allele was determined by nucleotide sequencing. The chemosensitivity of pancreatic carcinoma cells to 5-FU in vitro was evaluated using Cell Counting Kit-8 (CCK-8). TS protein expression was analyzed by Western blotting.

RESULTSSeven pancreatic carcinoma cell lines had different genotypes in terms of the 28-bp TS tandem repeat, as follows: homozygous 2R/2R (T3M4 and BxPC-3 cells), heterozygous 2R/3R (AsPC-1, Capan-1, and SU86.86), and homozygous 3R/3R (PANC-1 and COLO357). The optical density ratio of genotypes 3R/3R, 2R/2R and 2R/3R was 1.393 ± 0.374, 0.568 ± 0.032 and 0.561 ± 0.056, respectively. Cells with the 2R/3R or 3R/3R genotypes were further analyzed for the G to C SNP at nucleotide 12 of the second 28-bp repeat of the 3R allele, yielding heterozygous 2R/3Rc (AsPC-1, Capan-1, and SU86.86), homozygous 3Rg/3Rg (COLO357) and homozygous 3Rc/3Rc (PANC-1). The optical density ratio of homozygous 3Rg/3Rg cells and homozygous 3Rc/3Rc cells was 1.723 ± 0.062 and 1.063 ± 0.134, respectively, and this difference was statistically significant (P < 0.05). Cells with the 2R/2R and 2R/3R genotypes of TS were hypersensitive to 5-FU in vitro as compared with those with the 3R/3R cells.

CONCLUSIONSPolymorphisms in the TS gene influenced its protein expression and affected sensitivity of 5-FU in seven pancreatic cancer cell lines. Cells with the 3R/3R genotype had higher TS protein expression than the 2R/2R or 2R/3R genotypes. Cells of the 3R/3R genotype with high TS protein expression were shown lower 5-FU sensitivity than cells with the 2R/2R or 2R/3R genotypes. These data warrant large-scale clinical studies to assess the role of polymorphisms in the TS gene on its protein expression and chemosensitivity to 5-FU in pancreatic cancer.

Blotting, Western ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Fluorouracil ; pharmacology ; Humans ; Minisatellite Repeats ; genetics ; Pancreatic Neoplasms ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Single Nucleotide ; genetics ; Thymidylate Synthase ; genetics

INTRODUCTIONColorectal cancer is the most common form of malignancy in Taiwan and the third leading cause of death from cancer, preceded only by lung and hepatic cancers. Colorectal cancer is typically treated by surgical intervention and/or chemotherapy and radiotherapy, if necessary. To date, 5-fluorouracil (5-FU) is the most commonly used anti-cancer chemotherapy drug. However, patients commonly experience resistance to the drug therefore limiting its efficiency. In this study, we measured the expression of rTSbeta in human colon cancer as a novel 5-FU resistance marker.

MATERIALS AND METHODSWe collected 172 colon cancer samples from 4 different hospitals (including 21 pairs of colon cancer biopsies and 151 pathologic slides of colon cancer). In vitro, we measured the cytotoxicity of 5-FU and 5-FU plus leucovorin in H630 and H630-1 colon cancer cell lines.

RESULTSThe results revealed that rTSbeta was expressed in 115 (66.9 %) pathology samples and that tumour expression was higher than in corresponding normal tissue. Survival rates of up to 5 years following treatment was significantly higher for patients without rTSbeta expression than for those with rTSbeta expression (P = 0.0023). In vitro, H630-1 (with rTSbeta overexpression) had significantly higher IC50 of 5-FU than did H630. IC50 of 5-FU decreased when leucovorin was added.

CONCLUSIONSResults indicate a close relationship between rTSbeta expression and resistance to the drug 5-FU in human colorectal cancer. These results provide further evidence for rTSbeta expression as a novel 5-FU resistance marker of colorectal cancer.

Biomarkers ; Cell Line, Tumor ; drug effects ; Colorectal Neoplasms ; drug therapy ; Cytological Techniques ; Drug Resistance, Neoplasm ; physiology ; Fluorouracil ; pharmacology ; therapeutic use ; Humans ; In Vitro Techniques ; Taiwan ; Thymidylate Synthase ; genetics ; metabolism

OBJECTIVEThymidylate synthase (TS) catalyses the conversion of deoxy-uridylate to deoxy-thymidylate and is a key enzyme for DNA synthesis. TS is the target enzyme of 5-fluorouracil (5-FU) and involved in folate metabolism. TS gene polymorphisms play an important role in the efficiency of fluorouracil activity in vivo. This study investigated the allelic frequencies and distribution characters of single-nucleotide polymorphisms within the coding region (cSNPs) of TS gene in Chinese children with acute leukemia (AL) and normal control children in order to explore the possible relationship between the cSNP in human TS gene and chemotherapeutic effects of 5-fluorouracils.

METHODSBone marrow samples from 53 children with AL and peripheral blood samples from 115 normal children were obtained to prepare complementary DNAs (cDNAs). The cDNAs were analyzed for the polymorphisms in TS gene by reverse transcriptase (RT)-polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and direct sequencing. The distributive difference of each genotype between AL children and control children was evaluated.

RESULTSA polymorphism 381 A>G (E127E) in the coding region of TS gene was firstly identified in the Chinese population. The 381 A>G allelic frequency in AL children and control children was 12.3% and 13.5% respectively (P>0.05), which were similar to that in the International SNP Bank (12.3%). The allelic frequency of cSNPs was not associated with the susceptibility to AL.

CONCLUSIONSA polymorphism 381 A>G (E127E) in TS gene was successfully identified in children using RT-PCR-DGGE combined with DNA sequencing. There was no significant difference in the allelic frequency of cSNPs in AL children and normal children.

Acute Disease ; Child ; Child, Preschool ; Electrophoresis, Polyacrylamide Gel ; Female ; Humans ; Infant ; Infant, Newborn ; Leukemia ; genetics ; Male ; Polymorphism, Single Nucleotide ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sequence Analysis, DNA ; Thymidylate Synthase ; genetics

Individualized tailored therapy is a currently pursuing direction for improving the outcome of patients with colorectal cancer. Targeted therapy is the potential strategy to reach this goal by evaluating status of the presumed targets and their related effector molecules and by maximizing the efficacy of chemotherapeutic agents with less toxicity in individual patient. Numerous hurdles should be overcome, however, because therapeutic outcome can be affected by multiple components; tumor characteristics such as somatic mutations at the DNA, RNA, and protein levels; patient characteristics like germline genetic polymorphisms in enzymes linked to drug metabolism; and environmental factors that include diet and physical activity. Currently, large numbers of potential biomarkers have been proposed but have not yet accomplished supporting evidences for their routine usage in clinics. Therefore, clinical trials driven by molecular targets and relevant biomarkers for the understanding of the conflicting data are needed to make markers available in clinical practice.
Colorectal Neoplasms/*drug therapy/radiotherapy ; Combined Modality Therapy ; CpG Islands/genetics ; DNA Topoisomerases, Type I/genetics ; Humans ; Receptor, Epidermal Growth Factor/genetics ; Thymidylate Synthase/genetics ; Tumor Markers, Biological/*genetics

OBJECTIVETo study the relationship between multidrug-resistant (MDR) expression in nasopharyngeal carcinoma (NPC) and its sensitivity to chemotherapy.

METHODSThe specimens of 23 NPC cases were studied by immunohistochemistry with monoclonal antibody of P-glycoprotein (P-gp), multidrug resistance relation protein (MRP), lung-resistance related protein (LRP), topoisomerase II (Topo II), thymidylate synthase (TS), glutathione-S-transferase (GST-pi). Among them, 20 specimens were taken from primary NPC lesion which were treated with two course of cisplatin (DDP) and 5-fluorouracil (5-FU), 3 specimens were taken from cervical lymph-node of recurrent NPC patients who were treated by radical dissection.

RESULTSVarious MDR parameters were expressed differently in 22 cases except for 1 clear cell carcinoma case. The difference was statistically significant (P < 0.05). However, there were no significant difference of MDR expression either among various carcinoma pathomorphology cell groups or among different clinical stage groups. Expression of LRP and TS were found in 10 and 14 cases respectively and the chemotherapy responders rates were 20% (2/10) and 28.5% (4/14) respectively. While the chemotherapy responders rates were 70% (7/10) and 5/6 in cases without expression. There was significant difference (P < 0.001, and P < 0.05).

CONCLUSIONThe NPC patients with LRP and TS expression may be less sensitive to chemotherapy with DDP + 5-FU.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; Adult ; Aged ; Cisplatin ; pharmacology ; therapeutic use ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Drug Screening Assays, Antitumor ; Female ; Fluorouracil ; pharmacology ; therapeutic use ; Glutathione S-Transferase pi ; genetics ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; drug therapy ; genetics ; Thymidylate Synthase ; genetics ; Vault Ribonucleoprotein Particles ; genetics