Induction of reactive oxygen intermediates-dependent programmed cell death in human malignant ex vivo glioma cells and inhibition of the vascular endothelial growth factor production by taurolidine

Does taurolidine have any effect on liver regeneration and oxidation in the experimental hepatectomy model?

Objective: Taurolidine is a bicyclic molecule produced by the natural amino acid taurine. Antibacterial, antiendotoxic and cytoprotective effects of taurolidine have been shown experimentally. Data on the effects of taurolidine on oxidative stress and hepatic regeneration are limited. The aim of the study was to evaluate the effect of taurolidine on hepatic regeneration and oxidative stress in rats undergoing partial hepatectomy.

Material and Methods: Forty adult, male Wistar Albino rats were randomly divided into four equal groups: sham (S) group (n= 10), post-sham opera- tion taurolidine administered (ST) group (n= 10), partial hepatectomy (H) group (n= 10) and post-partial hepatectomy taurolidine administered (HT) group (n= 10). 100 mg/kg/day taurolidine was administered for seven days. Blood and liver tissue samples were collected on postoperative day seven. Liver tissue malondialdehyde, glutathione and Cu-Zn superoxide dismutase activity (SOD) were measured to assess oxidative stress. Binuclear hepato- cyte and Ki-67 antigen levels were measured to evaluate hepatic regeneration.

Results: There was no difference between the groups for malondialdehyde, Cu-Zn superoxide dismutase and glutathione levels (p> 0.05). Binuclear nuclei levels were comparable between the H and HT groups (p= 0.06), while taurolidine decreased binuclear hepatocyte levels in the sham operated groups (p= 0.02). Taurolidine application decreased Ki-67 levels after partial hepatectomy (p= 0.001).

Conclusion: Taurolidine may cause anti-regenerative effects after partial hepatectomy without causing oxidative damage.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

Dual functionality of the antimicrobial agent taurolidine which demonstrates effective anti-tumor properties in pediatric neuroblastoma

High-risk, relapsed and refractory neuroblastoma are associated with poor 5-years survival rates, demonstrating the need for investigational therapeutic agents to treat this disease. Taurolidine is derived from the aminosulfoacid taurine and has known anti-microbial and anti-inflammatory properties. Taurolidine has also demonstrated anti-neoplastic effects in a range of cancers, providing the rationale to investigate the activity of taurolidine against neuroblastoma in preclinical studies. We investigated the in vitro activity of taurolidine against neuroblastoma using the alamar blue cytotoxicity assay, phase-contrast light microscopy, western blotting and analysis of global gene expression by RNA-Seq. In vivo activity of taurolidine was evaluated using mouse xenograft models. In vitro pre-clinical data show that taurolidine is cytotoxic to neuroblastoma cell lines, inducing cell death by apoptosis. Analysis of global gene expression and determination of signaling pathway activation scores using the in silico Pathway Activation Network Decomposition Analysis (iPANDA) platform indicates that taurolidine has an effect on the Notch, mitogen-activated protein kinase (MAPK) and interleukin-10 (IL-10) signaling pathways. In vivo experiments in xenograft mouse models show that taurolidine decreases tumor growth and improves survival. These results provide supportive pre-clinical data on the activity of taurolidine against neuroblastoma. The findings support the rationale for further evaluation of taurolidine for the treatment of relapsed/refractory neuroblastoma patients in an early phase clinical trial.

Redox biology of regulated cell death in cancer: A focus on necroptosis and ferroptosis

Redox changes and generation of reactive oxygen species (ROS) are part of normal cell metabolism. While low ROS levels are implicated in cellular signaling pathways necessary for survival, higher levels play major roles in cancer development as well as cell death signaling and execution. A role for redox changes in apoptosis has been long established; however, several new modalities of regulated cell death have been brought to light, for which the importance of ROS production as well as ROS source and targets are being actively investigated. In this review, we summarize recent findings on the role of ROS and redox changes in the activation and execution of two major forms of regulated cell death, necroptosis and ferroptosis. We also discuss the potential of using modulators of these two forms of cell death to exacerbate ROS as a promising anticancer therapy.

N-Acetyl Cysteine Functions as a Fast-Acting Antioxidant by Triggering Intracellular H2S and Sulfane Sulfur Production

The cysteine prodrug N-acetyl cysteine (NAC) is widely used as a pharmacological antioxidant and cytoprotectant. It has been reported to lower endogenous oxidant levels and to protect cells against a wide range of pro-oxidative insults. As NAC itself is a poor scavenger of oxidants, the molecular mechanisms behind the antioxidative effects of NAC have remained uncertain. Here we show that NAC-derived cysteine is desulfurated to generate hydrogen sulfide, which in turn is oxidized to sulfane sulfur species, predominantly within mitochondria. We provide evidence suggesting the possibility that sulfane sulfur species produced by 3-mercaptopyruvate sulfurtransferase and sulfide:quinone oxidoreductase are the actual mediators of the immediate antioxidative and cytoprotective effects provided by NAC.

Innovative substance 2250 as a highly promising anti-neoplastic agent in malignant pancreatic carcinoma - in vitro and in vivo

BACKGROUND

Former studies already revealed the anti-neoplastic properties of the anti-infective agent Taurolidine (TRD) against many tumor species in vitro and in vivo. Its anti-proliferative and cell death inducing capacity is largely due to its main derivative Taurultam (TRLT). In this study it could be demonstrated, that substance 2250 - a newly defined innovative structural analogue of TRLT - exhibits an anti-neoplastic effect on malignant pancreatic carcinoma in vitro and in vivo.

METHODS

The anti-neoplastic potential of substance 2250 as well as its mode of action was demonstrated in extensive in vitro analysis, followed by successful and effective in vivo testings, using xenograft models derived from established pancreatic cancer cell lines as well as patient derived tissue.

RESULTS

Our functional analysis regarding the role of oxidative stress (ROS) and caspase activated apoptosis showed, that ROS driven programmed cell death (PCD) is the major mechanisms induced by substance 2250 in pancreatic carcinoma. What is strongly relevant towards clinical practice is especially the observed inhibition of patient derived pancreatic cancer tumor growth in mice treated with this new substance in combination with its sharply higher metabolic stability.

CONCLUSION

These encouraging results provide new therapeutical opportunities in pancreatic cancer treatment and build the basis for further functional analysis as well as first clinical studies for this promising agent.

Novel protective role of curcumin and taurine combination against experimental hepatocarcinogenesis

Hepatocarcinogenesis is a prerequisite to hepatocellular carcinoma (HCC), which is one of the most common cancers among humans. Therefore, it is important to search for agents that protect against hepatocarcinogenesis. The present study aimed to investigate the protective effects of a combination of taurine and curcumin against experimental hepatocarcinogenesis induced by diethyl nitrosamine (DENA) in a rat model. A total of 100 rats were divided into eight groups. Eight weeks following DENA injection and treatment with curcumin and taurine, the rats were sacrificed to obtain blood and hepatic tissue samples for the evaluation of various markers and histopathological observations. Serum levels of interleukin-2 (IL-2), interferon-γ (IFN-γ), α-fetoprotein (AFP) and α-L-fucosidase (AFU) were determined. Rats injected with DENA for eight weeks showed a high percentage of malignant changes in hepatic tissues, as well as a significant increases in the serum levels of AFP and AFU and significant reductions in the serum levels of IL-2 and IFN-γ. Treatment with curcumin and taurine markedly reduced the extent of malignant changes in the rat liver tissues, with their liver tissues showing patterns similar to that of the normal control rats. In addition, this combination resulted in normal serum levels of IL-2, IFN-γ, AFP and AFU. The results of the present study suggested that a combination of curcumin and taurine may be a novel prophylactic agent against hepatocarcinogenesis in high-risk groups exposed to chemical hepatocarcinogens.

Distinct Metabolomic Profiles of Papillary Thyroid Carcinoma and Benign Thyroid Adenoma

Papillary thyroid carcinoma (PTC) and benign thyroid adenoma (BTA) are the most common head and neck tumors. However, the metabolic differences between PTC and BTA have not been characterized. The aim of this study was to identify the metabolic profiles of these two types of tumors using a metabolomics approach. Tumors and adjacent nontumor specimens collected from 57 patients with PTC and 48 patients with BTA were profiled using gas chromatography-time-of-flight mass spectrometry and ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry. A panel of 46 and 44 differentially expressed metabolites were identified in the PTC and BTA specimens, respetively, and compared with nontumor tissues. Common metabolic signatures, as characterized by increased glycolysis, amino acid metabolism, one carbon metabolism and tryptophan metabolism, were found in both types of tumors. Purine and pyrimidine metabolism was significantly elevated in the PTC specimens, and taurine and hypotaurine levels were also higher in the PTC tissues. Increased fatty acid and bile acid levels were found, especially in the BTA tissues. The metabolic profiles of the PTC and BTA tissues include both similar and remarkably different metabolites, suggesting the presence of common and unique mechanistic pathways in these types of tumors during tumorigenesis.

Redox-directed cancer therapeutics: Taurolidine and Piperlongumine as broadly effective antineoplastic agents (review)

Targeting the oxygen stress response pathway is considered a promising strategy to exert antineoplastic activity in a broad spectrum of tumor types. Supporting this view, we summarize the mechanism of action of Taurolidine and Piperlongumine, two antineoplastic agents with strikingly broad tumor selectivity. Taurolidine enhances the oxidative stress (ROS) selectively in tumor cells. Its cytotoxicity for various tumor cells in vitro and in vivo, which includes tumor stem cells, is based on the induction of programmed cell death, largely via apoptosis but also necroptosis and autophagy. The redox-directed mechanism of action of Taurolidine is apparent from the finding that reducing agents e.g., N-acetylcysteine or glutathione impair its cytotoxicity, while its effectiveness is enhanced by agents which inhibit the cellular anti‑oxidant capacity. A similar redox-directed antineoplastic action is shown by Piperlongumine, a recently described experimental drug of plant origin. Taurolidine is particularly advantageous in surgical oncology as this taurine-derivative can be applied perioperatively or systemically with good tolerability as shown in initial clinical applications.

Targeting class IA PI3K isoforms selectively impairs cell growth, survival, and migration in glioblastoma

The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is frequently activated in human cancer and plays a crucial role in glioblastoma biology. We were interested in gaining further insight into the potential of targeting PI3K isoforms as a novel anti-tumor approach in glioblastoma. Consistent expression of the PI3K catalytic isoform PI3K p110α was detected in a panel of glioblastoma patient samples. In contrast, PI3K p110β expression was only rarely detected in glioblastoma patient samples. The expression of a module comprising the epidermal growth factor receptor (EGFR)/PI3K p110α/phosphorylated ribosomal S6 protein (p-S6) was correlated with shorter patient survival. Inhibition of PI3K p110α activity impaired the anchorage-dependent growth of glioblastoma cells and induced tumor regression in vivo. Inhibition of PI3K p110α or PI3K p110β also led to impaired anchorage-independent growth, a decreased migratory capacity of glioblastoma cells, and reduced the activation of the Akt/mTOR pathway. These effects were selective, because targeting of PI3K p110δ did not result in a comparable impairment of glioblastoma tumorigenic properties. Together, our data reveal that drugs targeting PI3K p110α can reduce growth in a subset of glioblastoma tumors characterized by the expression of EGFR/PI3K p110α/p-S6.

Taurine: a novel tumor marker for enhanced detection of breast cancer among female patients

INTRODUCTION

The antioxidant Taurine found to display antineoplastic effect through down regulation of angiogenesis and enhancement of tumor cell apoptosis. It has been found that progressive inhibition of apoptosis and induction of angiogenesis may contribute to tumor initiation, growth and metastasis in the pathogenesis of breast cancer.

AIM OF THE STUDY

To correlate taurine level with the levels of some bioomolecules operating in both angiogenesis (VEGF, CD31) and apoptosis (TNF-α and Caspas-3) which could help for breast cancer pronostication and to evaluate a possible role of serum taurine level as an early marker for breast cancer in Egyptian patients.

PATIENTS AND METHODS

Four groups of a total 85 female candidates were studied in this work. The first group consists of 50 female patients at National Cancer Institute (NCI), Cairo University were diagnosed and undergoing surgery for breast carcinoma. In the second group 10 having benign breast lesions, were included. The third group consists of five cases, with positive family history. Twenty healthy females were also recruited as control. A preoperative blood sample were taken from each patient to measure serum level of VEGF; Taurine; CA15.3 and TNF- α. Sample of fresh tumor and their corresponding safety margins were obtained from the first and second groups, for determination of caspase-3; histopathological examination and immunohistochemical assay of VEGF and CD31.

RESULT

No significant differences in the serum level of CA15.3 between the breast cancer patients, the high risk and the control group. TNF-α (apoptotic biomolecule) level showed a significant difference only between breast cancer group and control group. The VEGF (angiogenic biomarker) showed a highly significant difference between breast cancer patients, the high risk and the control group. Regarding the antioxidant taurine (antiangiogenic biomolecule) serum level in breast cancer group exhibited a value strongly lower than the high risk and control group. Also the correlative ratio between the angiogenic/apoptotic biomarker (VEGF/TNF-α) showed a highly significant difference between the main previous three groups. Same observation were also noticed in the correlation between angiogenic/antiangiogenic (VEGF/taurine) ratio in the same groups. Moreover the enzymatic activities of Casp-3 in the tissue homogenate were statistically higher in adjacent normal tissues than in malignant tissues. The result of immunohistochemical investigation showed a significant increase in the density of intracellular VEGF and microvessel density expressed as CD31 in cancer cases compared to normal adjacent tissue.

CONCLUSION

It is suggested that assessment of taurine level in sera of patients with high risk for breast cancer are of great value in the early diagnosis of malignant changes in the breast.

Gene expression analysis of cell death induction by taurolidine in different malignant cell lines

Background

The anti-infective agent Taurolidine (TRD) has been shown to have cell death inducing properties, but the mechanism of its action is largely unknown. The aim of this study was to identify potential common target genes modulated at the transcriptional level following TRD treatment in tumour cell lines originating from different cancer types.

Methods

Five different malignant cell lines (HT29, Chang Liver, HT1080, AsPC-1 and BxPC-3) were incubated with TRD (100 μM, 250 μM and 1000 μM). Proliferation after 8 h and cell viability after 24 h were analyzed by BrdU assay and FACS analysis, respectively. Gene expression analyses were carried out using the Agilent -microarray platform to indentify genes which displayed conjoint regulation following the addition of TRD in all cell lines. Candidate genes were subjected to Ingenuity Pathways Analysis and selected genes were validated by qRT-PCR and Western Blot.

Results

TRD 250 μM caused a significant inhibition of proliferation as well as apoptotic cell death in all cell lines. Among cell death associated genes with the strongest regulation in gene expression, we identified pro-apoptotic transcription factors (EGR1, ATF3) as well as genes involved in the ER stress response (PPP1R15A), in ubiquitination (TRAF6) and mitochondrial apoptotic pathways (PMAIP1).

Conclusions

This is the first conjoint analysis of potential target genes of TRD which was performed simultaneously in different malignant cell lines. The results indicate that TRD might be involved in different signal transduction pathways leading to apoptosis.

Oral administration of the anti-proliferative substance taurolidine has no impact on dextran sulfate sodium induced colitis-associated carcinogenesis in mice

Background:

New chemopreventive strategies for ulcerative colitis (UC)-associated dysplasia and cancer have to be evaluated. Taurolidine (TRD) has anti-inflammatory, anti-proliferative and anti-neoplastic properties with almost absent toxicity. The aim of the study was to determine whether TRD decreases dysplasia in the well-characterized Dextran Sulfate Sodium – Azoxymethane (DSS-AOM) animal model for UC-associated carcinogenesis.

Material and Methods:

The DSS-AOM model of carcinogenesis was induced in female inbred C57BL/6 mice. Half of the mice were treated with TRD, the other served as control. After 100 days macroscopic, histological and immunhistochemical (β-Catenin, E-Cadherin, SOX9, Ki-67, Cyclin-D1) examination of the colon was performed.

Results:

Incidence, multiplicity, grading and growth pattern of adenomas did not differ significantly between TRD and control group. In all animals, inflammatory changes were absent. Immunhistochemistry revealed increased expression of Ki-67, β-catenin, SOX9 and Cyclin-D1 in adenomas compared to normal mucosa – without significant difference between TRD and control treatment.

Conclusion:

Oral administration of TRD has no impact on DSS-induced colitis-associated carcinogenesis. However, SOX9 and Cyclin-D1 representing key members of the Wnt pathway have not yet been described in the DSS-AOM model of carcinogenesis – underlining the importance of this oncogenic pathway in this setting.

Comparative analysis of cell death induction by Taurolidine in different malignant human cancer cell lines

Background

Taurolidine (TRD) represents an anti-infective substance with anti-neoplastic activity in many malignant cell lines. So far, the knowledge about the cell death inducing mechanisms and pathways activated by TRD is limited. The aim of this study was therefore, to perform a comparative analysis of cell death induction by TRD simultaneously in different malignant cell lines.

Materials and methods

Five different malignant cell lines (HT29/Colon, Chang Liver/Liver, HT1080/fibrosarcoma, AsPC-1/pancreas and BxPC-3/pancreas) were incubated with increasing concentrations of TRD (100 μM, 250 μM and 1000 μM) for 6 h and 24 h. Cell viability, apoptosis and necrosis were analyzed by FACS analysis (Propidiumiodide/AnnexinV staining). Additionally, cells were co-incubated with the caspase Inhibitor z-VAD, the radical scavenger N-Acetylcystein (NAC) and the Gluthation depleting agent BSO to examine the contribution of caspase activation and reactive oxygen species in TRD induced cell death.

Results

All cell lines were susceptible to TRD induced cell death without resistance toward this anti-neoplastic agent. However, the dose response effects were varying largely between different cell lines. The effect of NAC and BSO co-treatment were highly different among cell lines - suggesting a cell line specific involvement of ROS in TRD induced cell death. Furthermore, impact of z-VAD mediated inhibition of caspases was differing strongly among the cell lines.

Conclusion

This is the first study providing a simultaneous evaluation of the anti-neoplastic action of TRD across several malignant cell lines. The involvement of ROS and caspase activation was highly variable among the five cell lines, although all were susceptible to TRD induced cell death. Our results indicate, that TRD is likely to provide multifaceted cell death mechanisms leading to a cell line specific diversity.

The evolving role of taurolidine in cancer therapy

BACKGROUND AND DESIGN

Taurolidine consists of two taurinamide rings derived from the naturally occurring amino acid taurine. It has been utilized to prevent adhesions, as an antimicrobial, and as an anti-inflammatory agent. More recently, it has been found to exert antineoplastic activity. We reviewed the literature regarding taurolidine and its role in cancer treatment.

RESULTS AND CONCLUSION

Taurolidine induces cancer cell death through a variety of mechanisms. Even now, all the antineoplastic pathways it employs are not completely elucidated. It has been shown to enhance apoptosis, inhibit angiogenesis, reduce tumor adherence, downregulate proinflammatory cytokine release, and stimulate anticancer immune regulation following surgical trauma. Apoptosis is activated through both a mitochondrial cytochrome-c-dependent mechanism and an extrinsic direct pathway. A lot of in vitro and animal data support taurolidine's tumoricidal action. Taurolidine has been used as an antimicrobial agent in the clinical setting since the 1970s and thus far appears nontoxic. The nontoxic nature of taurolidine makes it a favorable option compared with current chemotherapeutic regimens. Few published clinical studies exist evaluating the role of taurolidine as a chemotherapeutic agent. The literature lacks a gold-standard level 1 randomized clinical trial to evaluate taurolidine's potential antineoplastic benefits. However, these trials are currently underway. Such randomized control studies are vital to clarify the role of taurolidine in modern cancer treatment.

Endothelial cell barrier impairment induced by glioblastomas and transforming growth factor beta2 involves matrix metalloproteinases and tight junction proteins

Gliomas, particularly glioblastoma multiforme, perturb the blood-brain barrier and cause brain edema that contributes to morbidity and mortality. The mechanisms underlying this vasogenic edema are poorly understood. We examined the effects of cocultured primary cultured human glioblastoma cells and glioma-derived growth factors on the endothelial cell tight junction proteins claudin 1, claudin 5, occludin, and zonula occludens 1 of brain-derived microvascular endothelial cells and a human umbilical vein endothelial cell line. Cocultured glioblastoma cells and glioma-derived factors (e.g. transforming growth factor beta2) enhanced the paracellular flux of endothelial cell monolayers in conjunction with downregulation of the tight junction proteins. Neutralizing anti-transforming growth factor beta2 antibodies partially restored the barrier properties in this in vitro blood-brain barrier model. The involvement of endothelial cell-derived matrix metalloproteinases (MMPs) was demonstrated by quantitative reverse-transcriptase-polymerase chain reaction analysis and by the determination of MMP activities via zymography and fluorometry in the presence or absence of the MMP inhibitor GM6001. Occludin, claudin 1, and claudin 5 were expressed in microvascular endothelial cells in nonneoplastic brain samples but were significantly reduced in anaplastic astrocytoma and glioblastoma samples. Taken together, these in vitro and in vivo results indicate that glioma-derived factors may induce MMPs and downregulate endothelial tight junction protein and, thus, play a key role in glioma-induced impairment of the blood-brain barrier.

EGR-1 is regulated by N-methyl-D-aspartate-receptor stimulation and associated with patient survival in human high grade astrocytomas

Early growth response-1 (EGR-1) is considered a central regulator in tumor cell proliferation, migration and angiogenesis and a promising candidate for gene therapy in human astrocytomas. However, conflicting data have been reported suggesting that both tumor promoting and anti-tumor activity of EGR-1 and its regulation, expression and prognostic significance still remain enigmatic. Our study explored EGR-1 expression and regulation in astrocytomas and its association with patient survival. As we detected two EGR-1 mRNA variants, one containing a N-methyl-D-aspartate-receptor (NMDA-R) responsive cytoplasmic polyadenylation element (CPE), further experiments were performed to determine the functional role of this pathway. After NMDA stimulation of SV-FHAS and neoplastic astrocytes, real-time polymerase chain reaction showed an increase of the CPE, containing EGR-1 splice variant only in astrocytoma cells. The surface expression and functionality of NMDA-R were demonstrated by flow cytometric analysis and measurement of increased intracellular Ca(2+). EGR-1 was mainly restricted to tumor cells expressing NMDA-R and significantly up-regulated in astrocytic tumors compared with normal brain. Further, EGR-1 expression was significantly (P < 0.007) associated with enhanced patient survival and was an independent prognostic factor in multivariate analysis in high grade astrocytomas. The NMDA-R-mediated EGR-1 expression, therefore, seems to be a promising target for novel clinical approaches to astrocytoma treatment.

Synergistic effects in apoptosis induction by taurolidine and TRAIL in HCT-15 colon carcinoma cells

Induction of apoptosis in tumor cells by TRAIL (tumor necrosis factor [TNF]-related apoptosis-inducing ligand) is a promising therapeutic principle in oncology, although toxicity and resistance against TRAIL are limiting factors. Taurolidine (TRD), an antineoplastic agent with low toxicity, is a potential candidate for combined therapy with TRAIL. The aim of this study was to evaluate the apoptotic effects of a combined treatment with TRD and TRAIL in a human HCT-15 colon carcinoma cell line. HCT-15 cells were incubated with increasing concentrations of recombinant human TRAIL (50 ng/mL to 500 ng/mL) or TRD (50 micromol/L to 1000 micromol/L). In a second experiment, cells were furthermore exposed to a combination of both substances (TRAIL 50 ng/mL and TRD 100 micromol/L). At various time points (3 h to 36 h), cell viability, apoptosis, and necrosis were quantified by FACS analysis (propidium iodide/annexin V-FITC) and confirmed by TUNEL assay. Incubation with TRD resulted in cell death induction with maximum effects observed at 100 micromol/L and 1000 micromol/L after 36 h. TRAIL application led to dose-dependent cell death induction as early as 6 h. Combined treatment of TRD (100 micromol/L) and TRAIL (50 ng/mL) caused a sustained induction of apoptosis that was superior to single-agent application, exceeding a merely additive effect. Combinatory treatment of human colon carcinoma cells with TRD and TRAIL results in a synergistic effect on apoptosis induction with a significant increase of the apoptotic index. Combination of TRAIL with the nontoxic TRD might represent a novel therapeutic strategy in oncological therapy.

Pharmacokinetics of taurolidine following repeated intravenous infusions measured by HPLC-ESI-MS/MS of the derivatives taurultame and taurinamide in glioblastoma patients

BACKGROUND AND OBJECTIVE

Taurolidine is known to have antimicrobial activity. Furthermore, at lower concentrations, it has been found to exert a selective antineoplastic effect in vitro and in vivo. The aim of this study was to investigate the pharmacokinetics of taurolidine in vivo following repeated intravenous infusion in a schedule used for the treatment of glioblastoma. As a prerequisite, the pharmacokinetics of taurolidine in human blood plasma and whole blood in vitro was investigated.

PATIENTS AND METHODS

The pharmacokinetics of taurolidine and its derivatives taurultame and taurinamide were investigated in human blood plasma and in whole blood in vitro using blood from a healthy male volunteer. During repeated intravenous infusion therapy with taurolidine, plasma samples were taken every hour for a period of 13 hours per day in seven patients (three male, four female; mean age 48.4 +/- 12.8 years, range 27-66 years) with a glioblastoma. Following dansyl derivatisation, the concentrations of taurultame and taurinamide were determined using a new method based on high-performance liquid chromatography (HPLC) online coupled to electrospray ionisation tandem mass spectrometry (ESI-MS/MS) in the multiple reaction monitoring mode. Under the experimental conditions used, taurolidine could not be determined directly and was back-calculated from the taurultame and taurinamide values.

RESULTS

The new HPLC-ESI-MS/MS method demonstrated high accuracy and reproducibility. In vitro plasma concentrations of taurultame and taurinamide remained constant over the incubation period. In whole blood in vitro, a time-dependent formation of taurinamide was observed. At the start of the incubation, the taurultame-taurinamide ratio (TTR) was 0.95 at an initial taurolidine concentration of 50 microg/mL, and 1.69 at 100 microg/mL. The concentration of taurultame decreased at the same rate as the taurinamide concentration increased, showing logarithmic kinetics. The calculated taurolidine concentration remained largely constant over the 6-hour incubation period. During repeated infusions in patients, calculated plasma concentrations of taurolidine showed a strong increase after the start of each infusion and continued to increase until the end of infusion, followed by a rapid decline. The TTR was found to fluctuate between 0.1 and 0.3, depending on the relation to the previous or next infusion period. The volume of distribution was markedly higher for taurolidine, taurultame and taurinamide than the plasma volume.

CONCLUSIONS

Taurolidine displayed a stable pattern of derivatives in plasma in vitro, whereas in whole blood, a time- and concentration-dependent conversion was apparent. In patients, the calculated average taurolidine plasma concentration, achieved with the repeated infusion regimen, was in the antineoplastic-effective concentration range. The tissue concentrations of taurolidine and taurultame are expected to be higher than the plasma concentrations, taking into account the calculated volumes of distribution. Repeated infusion of taurolidine is the therapeutically adequate mode of administration for the indication of glioblastoma.

Taurolidine and povidone-iodine induce different types of cell death in malignant pleural mesothelioma

Taurolidine and povidone-iodine (PVP-I) are used in every day clinical practice, taurolidine as a broad spectrum antibiotic, and PVP-I as an antiseptic. The type of cell death induced in malignant pleural mesothelioma (MPM) cell lines by these agents was compared, and their ability to sensitize to chemotherapy assessed. Both taurolidine and PVP-I inhibited MPM cell growth after 7.5min incubation, but taurolidine was more effective at later time points and was more specific towards tumour cells than PVP-I. Taurolidine induced death by caspase-dependent and independent mechanisms, whereas in contrast, PVP-I induced a necrotic phenotype that was not caspase-dependent. Interestingly, both taurolidine and PVP-I induced the production of reactive oxygen intermediates and decreased mitochondrial membrane permeability, and cell death was inhibited by the oxygen scavenger N-acetyl cysteine. Taurolidine but not PVP-I treatment resulted in p53 activation in 2/3 MPM cell lines and a decrease in the protein levels of survivin, Bcl-2 and Mcl-1. Survivin also decreased in response to PVP-I whereas Bcl-xL remained unaffected by both treatments. Targeting of Bcl-xL with siRNA sensitized MPM cells to taurolidine and taurolidine treatment sensitized MPM cells to cisplatin-induced apoptosis. In conclusion, taurolidine and PVP-I are both cytotoxic to human MPM cells at early and late time points and induce reactive oxygen intermediate production. Taurolidine induces apoptosis and necrosis, activates p53 and sensitizes cells to cisplatin, whereas PVP-I inhibits cell growth via necrosis. Both agents are promising candidates for use in local treatment within multimodality concepts for MPM.

Taurolidine: a novel anti-neoplastic agent induces apoptosis of osteosarcoma cell lines

Taurolidine, the active agent of Taurolin, is a broad spectrum anti-biotic that has been used for over 15 years for the treatment of severe surgical infections. Recently, taurolidine has been shown to possess anti-neoplastic properties in vitro and in vivo against a variety of cancers including ovarian, colon and prostate. In this study we assessed the cytotoxic activity of taurolidine against human osteosarcoma (OS) cell lines and normal human bone cells. Treatment with taurolidine inhibited the growth of all ten osteosarcoma cell lines tested and taurolidine was equally potent against cell lines with and without distinct genetic defects (i.e. p53, Rb). Moreover, taurolidine-induced growth inhibition was found to be associated with a dose dependent increase in the number of apoptotic cells and apoptosis was shown to be caspase-dependent. Taurolidine treatment was also found to inhibit adhesion of OS cell lines. Compared to OS cell lines, normal bone cells in primary culture were found to be less sensitive to the cytotoxic and anti-adhesive effects of taurolidine. These data indicate that taurolidine possesses potent anti-neoplastic activity against osteosarcoma cell lines and may have potential as a novel OS chemotherapeutic agent.

Instillation of taurolidine/heparin after laparotomy reduces intraperitoneal tumour growth in a colon cancer rat model

OBJECTIVE

To investigate whether irrigation of the abdominal cavity after laparotomy for caecum resection with taurolidine/heparin or adhesion prophylactic substances reduces intraperitoneal tumour growth or the local recurrence rate in a colon carcinoma rat model.

METHODS

60 BDIX rats underwent caecum resection after intraperitoneal inoculation of 1 x 10(4) colon carcinoma cells (DHD/K12/TRb). Intergel, Interceed, taurolidine/heparin or NaCl 0.9% were intraperitoneally applied after randomisation. Finally, the total number and total weight of intraperitoneal metastases were determined as well as the adhesion score according to Moreno. Metastatic tissue was examined histologically and immunohistochemically (E-cadherin, CD44, beta(1)-integrin).

RESULTS

Taurolidine/heparin significantly reduced not only the total number (3 vs. 11 in the control group) but also the total weight (65 vs. 330 mg) of intraperitoneal metastases in comparison to the control group (p = 0.003 and p = 0.005). E-Cadherin expression in the metastatic tissue of animals treated with taurolidine/heparin was significantly decreased (p = 0.016).

CONCLUSION

Taurolidine/heparin effectively reduces intraperitoneal tumour growth when used as an intraoperative lavage. These results represent a good rationale for intraoperative adjuvant irrigation with taurolidine/heparin during resection of colon cancer.