Determinants of trifluorothymidine sensitivity and metabolism in colon and lung cancer cells

Temmink, Olaf H.; Bruin, Michiel de; Comijn, E. M.; Fukushima, Masakazu; Peters, Godefridus J.

doi:10.1097/00001813-200503000-00007

Cited by 23 publications

(29 citation statements)

References 26 publications

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“…In previous in vitro studies, we did not observe an advantage of TPI in a combination with TFT, even not in cancer cells with high TP expression (De Bruin et al, 2003;Temmink et al, 2005). This was despite previous observations that TPI was essential to observe an antitumour effect of TFT Emura et al, 2004c), by increasing the bioavailability of TFT (Emura et al, 2005).…”

Section: Discussioncontrasting

confidence: 91%

“…Both drugs were less effective in the wild-type Colo320, which was accompanied by less pronounced cell cycle effects and apoptosis. However, both 5 0 DFUR and capecitabine showed activity in the TP deficient Colo320, which is not in line with the large difference found in vitro (De Bruin et al, 2003;Temmink et al, 2005). The partial protection by TPI of 5 0 DFUR 0 s cytotoxicity against Colo320 demonstrates that 5 0 DFUR is systemically converted to 5FU, contradicting a selective cellular specificity of 5 0 DFUR.…”

Section: Discussionmentioning

confidence: 81%

“…TFT inhibits thymidylate synthase (TS) and is incorporated into the DNA (Eckstein et al, 1994;Emura et al, 2004d;Temmink et al, 2005). The inhibitor TPI is able to inhibit angiogenesis and metastasis by itself (Matsushita et al, 1999;Fukushima et al, 2000;Takao et al, 2000).…”

mentioning

confidence: 99%

“…It was previously shown in vivo that TPI in a ratio of 1 : 0.5 (TFT/TPI) was required to exert an in vivo activity (Emura et al, 2004c;Emura et al, 2005). However, in vitro TPI did not enhance the effect of TFT, also not in TP overexpressing cancer cells (De Bruin et al, 2003;Temmink et al, 2005). TAS-102 is currently undergoing clinical trials as an oral combination drug given in different schedules.…”

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confidence: 99%

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The hollow fibre assay as a model for in vivo pharmacodynamics of fluoropyrimidines in colon cancer cells

et al. 2006

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The Hollow Fibre Assay (HFA) is usually applied as an early in vivo model for anti-cancer drug screening, but is potentially an excellent model for short-term in vivo pharmacodynamic studies. We used the model to study the in vivo role of thymidine phosphorylase/ platelet-derived endothelial cell growth factor (TP/PD-ECGF) in the cytotoxicity and pharmacodynamics of TAS-102 in colon cancer cells. TAS-102 is a new oral drug formulation, which is composed of trifluorothymidine (TFT) and thymidine phosphorylase inhibitor (TPI), which prevents TFT degradation. We compared the activity with Xeloda (capecitabine), which is activated by TP into 5FU. Hollow fibres filled with human Colo320 or Colo320TP1 colorectal cancer cells with deficient or high TP expression, respectively, were implanted subcutaneously (s.c.) at both flanks of BALB/c mice. The mice were treated orally over 5 days with TAS-102, TFT alone, 5 0 DFUR7TPI or capecitabine at their maximum tolerated dose (MTD). The cells were retrieved from the fibres and assayed for growth (MTT assay), cell cycle distribution (flow cytometry) and apoptosis induction (FragEL method). TAS-102 induced considerable growth inhibition (50%, Po0.01) to both cell lines, which was completely abolished in the absence of TPI. Capecitabine and its metabolite 5 0 DFUR reduced proliferation of Colo320TP1 cells in the fibres significantly (down to 25 -40%), but much less in Colo320 cells, whereas addition of TPI reduced the effect of 5 0 DFUR, although not completely. These differences in cytotoxic effects were reflected in the pharmacodynamic evaluation. TAS-102 induced a G2M-phase arrest (from 25 to 40%) and apoptosis (48-fold), which was more pronounced in Colo320 than in Colo320TP1. Again, omission of TPI neutralised the effect of TAS-102. Similarly, 5 0 DFUR and capecitabine induced a significant G2M-phase arrest (up to 45%) in the Colo320TP1 cell line, but less pronounced in the parental Colo320. Addition of TPI to 5 0 DFUR reduced this effect to control levels. Also induction of apoptosis was reduced in the presence of TPI. The data demonstrated that the HFA is excellently suited for studying short-term pharmacodynamic effects of fluoropyrimidines in vivo. TAS-102 is only effective in inducing cytotoxicity when systemic TPI is present, but acts against both low and high TP expressing colon cancer cells, while 5 0 DFUR needs cellular TP to exert significant activity.

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Section: Discussioncontrasting

confidence: 91%

Section: Discussionmentioning

confidence: 81%

mentioning

confidence: 99%

mentioning

confidence: 99%

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The hollow fibre assay as a model for in vivo pharmacodynamics of fluoropyrimidines in colon cancer cells

et al. 2006

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“…Trifluorothymidine (TFT) is currently used as an antiviral agent (De Clercq, 2004) and is part of the novel oral antitumour Revised 3 November 2006; accepted 22 November 2006 drug preparation TAS-102 (Emura et al, 2004b;Tsuchiya et al, 2004;Temmink et al, 2005), which also consists of the antiangiogenic thymidine phosphorylase inhibitor TPI (Matsushita et al, 1999;Fukushima et al, 2000;Takao et al, 2000). TAS-102 is currently evaluated in different treatment schedules in phase I clinical trials (Hong et al, 2006).…”

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Mechanism of trifluorothymidine potentiation of oxaliplatin-induced cytotoxicity to colorectal cancer cells

et al. 2007

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Oxaliplatin (OHP) is an anticancer agent that acts by formation of Platinum-DNA (Pt-DNA) adducts resulting in DNA-strand breaks and is used for the treatment of colorectal cancer. The pyrimidine analog trifluorothymidine (TFT) forms together with a thymidine phosphorylase inhibitor (TPI) the anticancer drug formulation TAS-102, in which TPI enhances the bioavailability of TFT in vivo. In this in vitro study the combined cytotoxic effects of OHP with TFT were investigated in human colorectal cancer cells as a model for TAS-102 combinations. In a panel of five colon cancer cell lines (WiDr, H630, Colo320, SNU-C4 and SW1116) we evaluated the OHP-TFT drug combinations using the multiple drug -effect analysis with CalcuSyn software, in which the combination index (CI) indicates synergism (CIo0.9), additivity (CI ¼ 0.9 -1.1) or antagonism (CI41.1). Drug target analysis was used for WiDr, H630 and SW1116 to investigate whether there was an increase in Pt-DNA adduct formation, DNA damage induction, cell cycle delay and apoptosis. Trifluorothymidine combined with OHP resulted in synergism for all cell lines (all CIo0.9). This was irrespective of schedule in which either one of the drugs was kept at a constant concentration (using variable drug ratio) or when the two drugs were added in a 1 : 1 IC 50 -based molar ratio. Synergism could be increased for WiDr using sequential drug treatment schedules. Trifluorothymidine increased Pt-DNA adduct formation significantly in H630 and SW1116 (14.4 and 99.1%, respectively; Po0.05). Platinum-DNA adducts were retained best in SW1116 in the presence of TFT. More DNA-strand breaks were induced in SW1116 and the combination increased DNA damage induction (420%) compared with OHP alone. Exposure to the drugs induced a clear cell-cycle S-phase arrest, but was dose schedule and cell line dependent. Trifluorothymidine (TFT) and OHP both induced apoptosis, which increased significantly for WiDr and SW1116 after TFT -OHP exposure (18.8 and 20.6% respectively; Po0.05). The basal protein levels of ERCC1 DNA repair enzyme were not related to the DNA damage that was induced in the cell lines. In conclusion, the combination of TFT with the DNA synthesis inhibitor OHP induces synergism in colorectal cancer cells, but is dependent on the dose and treatment schedule used.

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Differential activation of cell death and autophagy results in an increased cytotoxic potential for trifluorothymidine compared to 5‐fluorouracil in colon cancer cells

Bijnsdorp

Peters

Temmink

et al. 2010

Intl Journal of Cancer

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Trifluorothymidine (TFT) is part of the oral drug formulation TAS-102. Both 5-fluorouracil (5-FU) and TFT can inhibit thymidylate synthase and be incorporated into DNA. TFT shows only moderate cross-resistance to 5-FU. Therefore, we examined whether mechanistic differences in cell death could underlie their different modes of action in colorectal cancer cell lines (WiDR, Lovo92 and Colo320). Drug cytotoxicity was determined by SRB-and clonogenic assays, cell death by flow cytometry (PI and annexin V), caspase cleavage by Western blotting and activity assays and in vivo activity in the hollow fiber assay. The IC 50 values of TFT were 1-6 fold lower than for 5-FU, and clonogenic survival was less than 0.9% at 3 lM TFT, while 2-20% of the cells still survived after 20 lM 5-FU. In general, TFT was a more potent inducer of apoptosis than 5-FU, although the contribution of caspases varied between the used cell lines and necrosis-like cell death was detected. Accordingly, both drugs induced caspase (Z-VAD) independent cell death and lysosomal cathepsin B was involved. Activation of autophagy recovery mechanisms was only triggered by 5-FU, but not by TFT as determined by LC3B expression and cleavage. Inhibition of autophagy by 3-MA in 5-FU exposed cells reduced cell survival. Also, in vivo TFT (as TAS-102) caused more cell death than a 5-FU formulation. We conclude that TFT and 5-FU induce cell death via both caspase-dependent and independent mechanisms. The TFT was more potent than 5-FU, because it induces higher levels of cell death and does not elicit an autophagic survival response in the cancer cell lines. This provides a strong molecular basis for further application of TFT in cancer therapy.5-Fluorouracil (5-FU) based therapy is part of the standard therapy for colorectal (CRC) and breast cancer. In order to exert its cytotoxic effect, 5-FU has to be activated to its monophosphate form, FdUMP. FdUMP is a strong irreversible inhibitor of thymidylate synthase (TS) by forming a stable ternary complex. In its triphosphate forms, FUTP and FdUTP, 5-FU can be incorporated into the RNA and DNA, respectively. 1 The effect of 5-FU in combination with leucovorin has increased survival, 2 but resistance is often encountered. 5-FU-resistance is related to a decreased level of 5-FUactivating enzymes, including orotate phosphoribosyl-transferase and uridine kinase, 3 and an increased expression of the target TS. 4 Recent improvements have been made by replacing bolus injections and inconvenient continuous infusions by oral fluoropyrimidine formulations, such as Xeloda (capecitabine) and UFT. 5 Another type of oral formulation, TAS-102, has recently been introduced into the clinic and consists of trifluorothymidine (TFT), in combination with a specific inhibitor of thymidine phosphorylase (TP), TPI. TAS-102, is currently tested in phase II studies against colorectal and gastric cancer. 6 Similar to 5-FU, TFT can inhibit TS in its monophosphate form (TF-TMP), 7 however TFT does not form a ternary complex as for 5-FU, but binds co...

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Determinants of trifluorothymidine sensitivity and metabolism in colon and lung cancer cells

Cited by 23 publications

References 26 publications

The hollow fibre assay as a model for in vivo pharmacodynamics of fluoropyrimidines in colon cancer cells

The hollow fibre assay as a model for in vivo pharmacodynamics of fluoropyrimidines in colon cancer cells

Mechanism of trifluorothymidine potentiation of oxaliplatin-induced cytotoxicity to colorectal cancer cells

Differential activation of cell death and autophagy results in an increased cytotoxic potential for trifluorothymidine compared to 5‐fluorouracil in colon cancer cells

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