Ehrlich Ascites Tumor Cells Research Articles

Stimulation of glucose uptake byMusasp. (cv. elakki bale) flower and pseudostem extracts in Ehrlich ascites tumor cells

Glucose uptake study plays a major role in diabetes research. Impaired glucose uptake has been implicated in the development of hyperglycemia during diabetes. Banana plant is known for its anti-diabetic properties and our earlier report revealed that banana flower and pseudostem of Musa sp. cv. elakki bale is beneficial during diabetes in rat models. The present study was designed to evaluate the potential effect of banana flower and pseudostem extracts on glucose uptake in Ehrlich ascites tumor (EAT) cells using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG), a fluorescent analogue of 2-deoxyglucose. Methanol and aqueous extracts of banana flower and pseudostem were more potent in promoting glucose uptake in EAT cells, in comparison to acetone and ethanol extracts. At 20 µg dosage, highest net glucose uptake was observed in aqueous extracts of banana flower (18.17 ± 0.43 nmol L⁻¹) and pseudostem (19.69 ± 0.41 nmol L⁻¹). Total polyphenol content was higher in methanol (9.031 ± 0.036 g kg⁻¹) and aqueous (6.862 ± 0.024 g kg⁻¹) extracts of banana flower compared to pseudostem, which were 0.442 ± 0.006 and 0.811 ± 0.011 g kg⁻¹, respectively. Banana flower and pseudostem extracts are able to promote glucose uptake into the cells, presumably through glucose transporters 1 and 3, which could be beneficial in diabetes. Glucose uptake is likely promoted by phenolic acids besides other bioactives. It can be hypothesized that consumption of nutraceutical-rich extract of banana flower and pseudostem could replace some amount of insulin being taken for diabetes.

In vivo peritoneal antiangiogenesis and in vitro antiproliferative properties of some bischalcone derivatives

In this study, three, bisarylidene cyclopentanones (curcumin analogs) 3a–c are synthesized by Claisen Schmidt condensation reaction. Antiangiogenic effects of the compounds were studied in Ehrlich ascites tumor (EAT) cells transplanted mouse in vivo. Antiangiogenic effect of 3a–c showed reduction in ascites volume, cell number, and induced apoptotic bodies in EAT cells in tested animals. The antiproliferative effects of the 3a–c were determined at different concentrations by MTT assay on HepG2 and HeLa cells. The compounds showed significant antiproliferative activity at 40 μM concentration. Compound 3a (fluoro derivative) showed highest antiproliferative effect with the IC50 value 39 and 48 μm for HeLa and HepG2, respectively. Growth inhibition of the HeLa cells and antiangiogenesis was mediated by promoting apoptosis which was confirmed by DNA fragmentation study.

Inhibition of ascites tumor growth in vivo by sTie‐2 is potentiated by a combinatorial therapy with sFLT‐1

Inhibition of tumor angiogenesis is a promising approach for cancer therapy and the Tie-2/angiopoietin pathway appears to play an important role. In the present study, we have developed strategies to explore the therapeutic potential of blocking the Tie-2/angiopoietin pathway by sTie-2. Ehrlich ascites tumor (EAT) cells were stably transfected to overexpress a truncated form of sTie-2. Transfectants were characterized for their in vitro growth behavior and transplanted into nude mice. Furthermore, recombinant sTie-2 produced by the baculovirus expression system was used to sequester angiopoietins in the murine ascites carcinoma model. The effect of sTie-2 treatment alone or in combination with sFLT-1 on the weight of the animal, ascites cell number and volume was studied. EAT cells stably transfected with a truncated form of sTie-2 showed no change in cell proliferation in vitro and colony forming in soft agar compared to control cells. However, sTie-2 transfected EAT cells transplanted into nude mice reduced tumor burden and demonstrated a reduction in ascites formation and peritoneal angiogenesis. Recombinant sTie-2 showed angiogenic activity in the tube formation and wound healing assay in vitro. sTie-2 treatment alone or in combination with sFLT-1 in an ascites tumor mouse model resulted in reduced peritoneal angiogenesis, with a concomitant decrease in tumor cell number, volume of ascites and the number of invasive tumor cells, as assayed by CD31 staining. The findings of the present study demonstrate an important role for the Tie-2/angiopoietin pathway in the formation of tumor vasculature and suggest that sTie-2 might yield useful anticancer therapy.

Relationship between Proliferation of Ehrlich Ascitic Tumor Cells and Status of the Chalone System under Conditions of Modified Photoregimen

The effects of permanent darkness on proliferation of Ehrlich ascitic tumor cells and status of the chalone system in the tumor were studied. Chalone-containing preparations from animals exposed to different light conditions exhibited different biological effects on cell proliferation in this tumor. A relationship between biological activity of chalone-containing preparations and sensitivity of tumor cells to these preparations under conditions of modified photoregimen was revealed.

Antitumor effects of nano-bubble hydrogen-dissolved water are enhanced by coexistent platinum colloid and the combined hyperthermia with apoptosis-like cell death

In order to erase reactive oxygen species (ROS) related with the proliferation of tumor cells by reducing activity of hydrogen, we developed functional water containing nano-bubbles (diameters: <900 nm for 71%/population) hydrogen of 1.1-1.5 ppm (the theoretical maximum: 1.6 ppm) with a reducing ability (an oxidation-reduction potential -650 mV, normal water: +100-200 mV) using a microporous-filter hydrogen-jetting device. We showed that hydrogen water erased ROS indispensable for tumor cell growth by ESR/spin trap, the redox indicator CDCFH-DA assay, and was cytotoxic to Ehrlich ascites tumor cells as assessed by WST-8 assay, crystal violet dye stain and scanning electron microscopy, after 24-h or 48-h incubation sequent to warming at 37°C or 42°C. Hydrogen water supplemented with platinum colloid (0.3 ppm Pt in 4% polyvinylpyrrolidone) had more antitumor activity than hydrogen water alone, mineral water alone (15.6%), hydrogen water plus mineral water, or platinum colloid alone as observed by decreased cell numbers, cell shrinkage and pycnosis (nuclear condensation)/karyorrhexis (nuclear fragmentation) indicative of apoptosis, together with cell deformation and disappearance of microvilli on the membrane surface. These antitumor effects were promoted by combination with hyperthermia at 42°C. Thus, the nano-bubble hydrogen water with platinum colloid is potent as an anti-tumor agent.

Development and characterization of hyaluronic acid decorated PLGA nanoparticles for delivery of 5-fluorouracil

The present investigation was aimed to develop and explore the prospective of engineered PLGA nanoparticles as vehicles for targeted delivery of 5-fluorouracil (5-FU). Nanoparticles of 5-FU-loaded hyaluronic acid-poly(ethylene glycol)-poly(lactide-co-glycolide) (HA-PEG-PLGA-FU) copolymer were prepared and characterized by FTIR, NMR, transmission electron microscopy, particle size analysis, DSC, and X-ray diffractometer measurement studies. The nanoparticulate formulation was evaluated for in vitro release, hemolytic toxicity, and hematological toxicity. Cytotoxicity studies were performed on Ehrlich ascites tumor (EAT) cell lines using MTT cell proliferation assay. Biodistribution studies of 99mTc labeled formulation were conducted on EAT-bearing mice. The in vivo tumor inhibition study was also performed after i.v. administration of HA-PEG-PLGA-FU nanoparticles. The HA conjugated formulation was found to be less hemolytic but more cytotoxic as compared to free drug. The hematological data suggested that HA-PEG-PLGA-FU formulation was less immunogenic compared to plain drug. The tissue distribution studies displayed that HA-PEG-PLGA-FU were able to deliver a higher concentration of 5-FU in the tumor mass. In addition, the HA-PEG-PLGA-FU nanoparticles reduced tumor volume significantly in comparison with 5-FU. Thus, it was concluded that the conjugation of HA imparts targetability to the formulation, and enhanced permeation and retention effect ruled out its access to the non-tumor tissues, at the same time favored selective entry in tumors, thereby reducing the side-effects both in vitro and in vivo.

Robert Kellogg Crane: A scientist remembers

Robert Kellogg Crane: A scientist remembers

Activation of the TASK-2 channel after cell swelling is dependent on tyrosine phosphorylation

The swelling-activated K(+) currents (I(K,vol)) in Ehrlich ascites tumor cells (EATC) has been reported to be through the two-pore domain (K(2p)), TWIK-related acid-sensitive K(+) channel 2 (TASK-2). The regulatory volume decrease (RVD), following hypotonic exposure in EATC, is rate limited by I(K,vol) indicating that inhibition of RVD reflects inhibition of TASK-2. We find that in EATC the tyrosine kinase inhibitor genistein inhibits RVD by 90%, and that the tyrosine phosphatase inhibitor monoperoxo(picolinato)-oxo-vanadate(V) [mpV(pic)] shifted the volume set point for inactivation of the channel to a lower cell volume. Swelling-activated K(+) efflux was impaired by genistein and the Src kinase family inhibitor 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2) and enhanced by the tyrosine phosphatase inhibitor mpV(pic). With the use of the TASK-2 inhibitor clofilium, it is demonstrated that mpV(pic) increased the volume-sensitive part of the K(+) efflux 1.3 times. To exclude K(+) efflux via a KCl cotransporter, cellular Cl(-) was substituted with NO(3)(-). Also under these conditions K(+) efflux was completely blocked by genistein. Thus tyrosine kinases seem to be involved in the activation of the volume-sensitive K(+) channel, whereas tyrosine phosphatases appears to be involved in inactivation of the channel. Overexpressing TASK-2 in human embryonic kidney (HEK)-293 cells increased the RVD rate and reduced the volume set point. TASK-2 has tyrosine sites, and precipitation of TASK-2 together with Western blotting and antibodies against phosphotyrosines revealed a cell swelling-induced, time-dependent tyrosine phosphorylation of the channel. Even though we found an inhibiting effect of PP2 on RVD, neither Src nor the focal adhesion kinase (FAK) seem to be involved. Inhibitors of the epidermal growth factor receptor tyrosine kinases had no effect on RVD, whereas the Janus kinase (JAK) inhibitor cucurbitacin inhibited the RVD by 40%. It is suggested that the cytokine receptor-coupled JAK/STAT pathway is upstream of the swelling-induced phosphorylation and activation of TASK-2 in EATC.

Evaluation of morphine effect on tumour angiogenesis in mouse breast tumour model, EATC

Breast cancer is the leading cause of death among women, and morphine is used to relieve the pain of patients with cancer. The data on the effects of morphine on tumour growth and angiogenesis are contradictory. We determined in mouse breast cancer model whether analgesic doses of morphine would affect tumour angiogenesis, and then the correlation between microvessel density (MVD), Doppler sonography (DS) and 99mTc-Tetrofosmin (TF) uptake. Ehrlich ascites tumour cell xenografts, Pgp-negative tumour were divided into two groups: (a) Morphine sulphate [0.714 mg/kg/day (equivalent to 50 mg per day for a 70 kg human)], (b) no-morphine. For the determination of angiogenesis in mice tumour tissue, TF scintigraphy, microvessel density and DS were done. MVD was significantly different between groups (49.4±1.8 vs. 41.8±1.9, morphine and no-morphine groups, respectively, P<0.001). A strong correlation was found between late uptakes of mass at scintigraphy and degree of angiogenesis in histopathologic examination (r=0.52, P<0.01). There was statistically significant inverse correlation between degree of angiogenesis in histopathologic examination and washout ratio of TF (r=0.40, P<0.05). The higher values for angiogenesis are related to higher TF reuptake. There was no statistically significant correlation between DS and TF. A strong correlation was found between MVD and grade of DS (r=0.51, P<0.01). Our preclinical mice study indicates that morphine at clinically relevant doses stimulates angiogenesis, and angiogenesis triggered of morphine is demonstrated with MVD and DS, but not TF. However, uptake and washout of TF are compared with immunohistochemically assessed morphine-stimulated angiogenesis in tumour tissue.

Letter to the editor: AVD1, AVDT, AVD2 in cisplatin-induced apoptosis: differences between WT EATC and MDR EATC resting on differing expression levels of type-1 porin/VDAC in cell membranes?

Combining data on mammalian VDAC with those of Poulsen and colleagues (5), a testable model of interpretation arises: cisplatin first opens type-1 porin at the cell membrane to initiate AVD1. After about 12 h, AVDT starts, showing similarity to regulatory volume increase. Finally, cisplatin reaches VDAC at OMM, thus stimulating caspase-dependent AVD2. Differences between WT EATCs and MDR EATCs under study might just rest on different expression levels of VDAC in their cell membranes; however, differences in the expression levels of plasmalemmal VDAC have been stated for normal or prostate cancer cells, respectively, taken from a single patient (3). Effects observed under the influence of the anion channel blocker NS3728 should also be seen under VDAC blockers. Finally, it might be worthwhile to refer to data on a putative opener of VDAC in cell membranes (10).

Atividade citotóxica e antiangiogênica de Punica granatum L., Punicaceae

Punica granatum L., a plant widely used in Brazil, was tested for its antitumor and antiangiogenic activities in vitroand in vivo. In this work, the in vitrocytotoxicity was evaluated using the K-562 cell line and Ehrlich ascites tumour cells, by MTT tetrazolium reduction test and the trypan blue exclusion test. In vivostudies investigated the increase in the survival time of Ehrlich tumour-bearing mice after treatment with different doses of Punica granatumL. ethanol extract (12.5; 25; 50 e and 100 mg/kg), by gavages, for ten consecutive days. In addition, we also investigated the tumour inhibition potential and antiangiogenic activity of this plant. In vitroresults demonstrated a decrease of K-562 and Ehrlich ascites tumour cells viability, with both methods used, in a dependent-manner concentration. In vivoresults showed a significant antitumor activity against Ehrlich ascites tumour growth, increasing survival time. In parallel, we detected a significant inhibition of the tumour growth, along with a decrease in the vascular pattern of the peritoneal wall. Thus, the data presented herein clearly showed that Punica granatum L. has antitumor and antiangiogenic activities.

Growth inhibition and pro-apoptotic activity of violacein in Ehrlich ascites tumor

The continuing threat to biodiversity lends urgency to the need of identification of sustainable source of natural products. This is not so much trouble if there is a microbial source of the compound. Herein, violacein, a natural indolic pigment extracted from Chromobacterium violaceum, was evaluated for its antitumoral potential against the Ehrlich ascites tumor (EAT) in vivo and in vitro. Evaluation of violacein cytotoxicity using different endpoints indicated that EAT cells were twofold (IC 50 = 5.0 μM) more sensitive to the compound than normal human peripheral blood lymphocytes. In vitro studies indicated that violacein cytotoxicity to EAT cells is mediated by a rapid (8–12 h) production of reactive oxygen species (ROS) and a decrease in intracellular GSH levels, probably due to oxidative stress. Additionally, apoptosis was primarily induced, as demonstrated by an increase in Annexin-V positive cells, concurrently with increased levels of DNA fragmentation and increased caspase-2, caspase-9 and caspase-3 activities up to 4.5-, 6.0- and 5.5-fold, respectively, after 72 h of treatment. Moreover, doses of 0.1 and 1.0 μg kg −1 violacein, administered intraperitoneally (i.p.) to EAT-bearing mice throughout the lifespan of the animals significantly inhibited tumor growth and increased survival of mice. In view of these results, a 35-day toxicity study was conducted in vivo. Complete hematology, biochemistry (ALT, AST and creatinine levels) and histopathological analysis of liver and kidney indicated that daily doses of violacein up to 1000 μg kg −1 for 35 days are well tolerated and did not cause hematotoxicity nor renal or hepatotoxicity when administered i.p. to mice. Altogether, these results indicate that violacein causes oxidative stress and an imbalance in the antioxidant defense machinery of cells culminating in apoptotic cell death. Furthermore, this is the first report of its antitumor activity in vivo, which occurs in the absence of toxicity to major organs.

Structure‐activity relationships of (1′S)‐acetoxychavicol acetate for the decrease in intracellular glutathione level in Ehrlich ascites tumor cells

We examined the structure‐activity relationships of (1′S)‐Acetoxychavicol acetate ((S)‐ACA), an anticarcinogenic compound naturally obtained from the rhizomes and the seeds of the Zingiberaceae plant, for the decrease in intracellular GSH making comparison with the activity of some synthetic‐related compounds in Ehrlich ascites tumor cells. (R)‐ACA and rac‐ACA caused the inhibition of cell viability similarly as (S)‐ACA. In previous study, we have shown that (S)‐ACA caused a rapid decrease in GSH level in less than 15 min after (S)‐ACA exposure. The addition of (R)‐ACA and rac‐ACA also caused the decrease in cellular GSH in Ehrlich ascites tumor cells. (S)‐ACA and (R)‐ACA induced cell death was reversed by the addition of N‐acetlycysteine. Therefore, we examined the inhibitory activities of rac‐ACA and its 9 derivatives toward the viability, the intracellular GSH level and GR activity in the cells was remarkably decreased with the treatment of rac‐ACA, rac‐3,4‐ACA, rac‐2,4‐ACA, rac‐trp‐7c‐ACA and rac‐BCB, but not changed with 20 μM concentration of 3′‐ACA, rac‐m‐ACA, rac‐o‐ACA, rac‐ADC, and rac‐DHACA. We also found that there is a highly significant correlation between GR activities and GSH levels and suggested that the decrease in the intracellular GSH levels was mainly caused by the decrease in the activity of GR in less than 15 min after ACAs exposure in Ehrlich ascites tumor cells.

Comparison of glutathione reductase activity and the intracellular glutathione reducing effects of 13 derivatives of 1′-acetoxychavicol acetate in Ehrlich ascites tumor cells

In a previous study, we showed that (1′ S)-acetoxychavicol acetate (( S)-ACA) caused a rapid decrease in glutathione (GSH) levels less than 15 min after exposure. ( S)-ACA-induced cell death was reversed by the addition of N-acetylcysteine. In the current study, we investigated the inhibitory activities of 13 derivatives of ( S)-ACA on tumor cell viability, intracellular GSH level and GR activity. Correlations were found among a decrease in cell viability, intracellular GSH levels and the activity of GR in Ehrlich ascites tumor cells treated with the various ACA analogues. A test of the 13 derivatives revealed that the structural factors regulating activity were as follows: (1) the para or 1′-position of acetoxyl group (or other acyl group) was essential, (2) the presence of a C2′–C3′ double or triple bond was essential, and (3) the S configuration of the 1′-acetoxyl group was preferable.

Secretion and hydrolysis of ATP by Ehrlich ascites tumor cells during centrifugation. Dependence on calcium and temperature

Precipitation of Ehrlich ascites tumor cells (EATC) by centrifugation causes ATP secretion. ATP secretion is accompanied by an increase of calcium concentration in the cytosol and persists for a long time (minutes) after centrifugation during the storage of cells at a low temperature. During prolonged storage (for more than 1.5 h), the concentration of extracellular ATP decreases to the level of ∼100 nM due to termination of secretion and ATP hydrolysis by surface ATPases. The rate of ATP hydrolysis exponentially falls with the temperature decrease from 36 to 8°C. ARL67156, a selective inhibitor of E-NTPDase-1, effectively suppresses the extracellular ATP hydrolysis. The intensity of ATP secretion does not correlate with the calcium ions concentration in the cytosol and Ca2+ mobilization from endoplasmic reticulum but correlates with the intensity of Ca2+ influx into the cells. The temperature dependences of ATP secretion intensity and Ca2+ entry rate coincide.

E‐selectin targeting to visualize tumorsin vivo

Generally angiogenic factors induce the expression of E-selectin in vascular endothelial cells in the tumors. In this study, we employed an anti-E-selectin monoclonal antibody to target tumors in vivo and evaluated an optical imaging reagent to visualize tumor regions. The anti-E-selectin antibody was conjugated on the surface of liposomes, which encapsulated the near-infrared fluorescent substances Cy3 or Cy5.5. The liposomes efficiently recognized human umbilical vein endothelial cells only when E-selectin was induced by angiogenic factors such as TNF-alpha in vitro. Cy5.5 encapsulated into liposomes that were conjugated with an anti-E-selectin antibody successfully visualized Ehrlich ascites tumor cells when transplanted into mice. Thus, E-selectin targeting with liposomes containing a near-infrared fluorescent dye was found effective in visualizing tumors in vivo. This strategy should be extremely useful as a method to identify sentinel lymphatic nodes and angiogenic tumors as well as use for drug delivery to tumor cells.

S100A6 binding protein and Siah-1 interacting protein (CacyBP/SIP): spotlight on properties and cellular function

The CacyBP/SIP protein (S100A6 binding protein and Siah-1 interacting protein) was originally discovered in Ehrlich ascites tumor cells as a S100A6 (calcyclin) target (Filipek and Wojda in Biochem J 320:585-587, 1996; Filipek and Kuźnicki in J Neurochem 70(5):1793-1798, 1998) and later on as a Siah-1 interacting protein (Matsuzawa and Reed in Mol Cell 7(5):915-926, 2001). CacyBP/SIP binds several target proteins such as some calcium binding proteins of the S100 family (Filipek et al. in J Biol Chem 277(32):28848-28852, 2002), Skp1 (Matsuzawa and Reed in Mol Cell 7(5):915-926, 2001), tubulin (Schneider et al. in Biochim Biophys Acta 1773(11):1628-1636, 2007) and ERK1/2 (Kilanczyk et al. in Biochem Biophys Res Commun 380:54-59, 2009). Studies concerning distribution of CacyBP/SIP show that it is present in various tissues and that a particularly high level of CacyBP/SIP is observed in brain (Jastrzebska et al. in J Histochem Cytochem 48(9):1195-1202, 2000). Regarding the function of CacyBP/SIP, there are some reports suggesting its role in cellular processes such as ubiquitination, proliferation, differentiation, tumorigenesis, cytoskeletal rearrangement or regulation of transcription. This review describes the properties of CacyBP/SIP and summarizes all findings concerning its cellular function.

A new insulin-mimetic vanadyl complex, (N-pyridylmethylaspartate)oxovanadium(IV) with VO(N2O2) coordination mode, and evaluation of its effect on uptake of D-glucose by Ehrlich ascites tumour cells.

Because it has been confirmed that the vanadyl(IV) ion and its complexes act as insulin mimetics, a new organic vanadyl complex, (N-pyridylmethylaspartate)oxovanadium (VOPASP) with VO(N2O2) coordination mode, was prepared. Development of a simple and rapid in-vitro assay is needed for recognition of potent insulin-mimetic complexes. Treatment of Ehrlich ascites tumour cells with 2-deoxyglucose in the presence of vanadyl sulphate, or other vanadyl complexes with the same coordination mode (VOPASP, bis(picolinate)oxovanadium (VOPA) and bis(6-methyl picolinate)oxovanadium (VOMPA)), in the presence of 2-deoxy-D-[1-3H]glucose ([3H]deoxyglucose), resulted in concentration-dependent uptake of 2-deoxyglucose by the cells. The responses of the cells to the vanadyl complexes were reflected, in part, by results obtained from the free fatty acid-releasing assay using rat adipocytes. These results show that the in-vitro assay with Ehrlich ascites tumour cells provides an accurate and rapid assessment of glucose uptake by the cells. The assay is proposed as a means of predicting the insulin-mimetic activity of the vanadyl complexes and for studying the mechanism of action of the complexes.

Evaluation of acetone cyanohydrin effect in "in vitro" inativation of the Ehrlich ascites tumor cells

To evaluate the antitumor effect of acetone cyanohydrin in Ehrlich ascites tumor cells in vitro. The Ehrlich ascites tumor cells and lymphocytes were incubated with different concentrations of acetone cyanohydrin (0, 0.5, 1.0, 2.0, 10.0, 20.0 and 30.0 microg x mL(-1)), After 1, 2, 3, 4, 18 and 24 hours cell viability tests were performed by the trypan blue method. The results demonstrated a dose-dependent cytotoxic effect against the cells of Ehrlich ascites tumor. The concentrations of 20 and 30 microg x mL(-1) was 100% of cell death in only 1 and 2 hours respectively. In lower doses of 0.5, 1.0 and 2.0 microg x mL(-1) the cytotoxic effect was less intense, increasing gradually with time. At low concentrations of 0.5, 1.0 and 2.0 microg x mL(-1), more than 90% of cell death was observed only after 24 hours of incubation which is the evidence that the tumor cell has the ability to poison cumulatively and irreversibly itself with the acetone cyanohydrin when compared with the results presented by human lymphocytes that the same doses and at the same time of incubation reached a maximum of 30% of cell death, suggesting an activity of rhodanese differentiated between the two cells.

Pinpointing Differences in Cisplatin-induced Apoptosis in Adherent and Non-adherent Cancer Cells

Platinum compounds are used in the treatment of cancer. We demonstrate that cisplatin-induced (10 µM) apoptosis (caspase-3 activity) is pronounced within 18 hours in non-adherent Ehrlich ascites tumour cells (EATC), whereas there is no increase in caspase-3 activity in the adherent Ehrlich LettrÉ ascites tumour cells (ELA). Loss of KCl and cell shrinkage are hallmarks in apoptosis and has been shown in EATC. However, we find no reduction in cell volume and only a minor loss of K⁺ which is accompanied by net uptake of Na⁺ following 18 hours cisplatin exposure in ELA. Glutathione and taurine have previously been demonstrated to protect cells from apoptosis. We find, however, that increase or decrease in the cellular content of glutathione and taurine has no effect on cisplatin-induced cell death in EATC and ELA. Nevertheless, knock-down of the taurine transporter TauT leads to a significant increase in apoptosis in ELA following cisplatin exposure. We find that cytosolic accumulation of cisplatin is similar in EATC and ELA. However, the nuclear accumulation and DNA-binding of cisplatin is significant lower in ELA compared to EATC. We suggest three putative reasons for the observed cisplatin insensitivity in the adherent tumor cells (ELA) compared to the non-adherent tumor cells (EATC): less nuclear cisplatin accumulation, increased TauT activity, and decreased anion and water loss.