Evaluation of the promiscuous component of several bacterial export pumps TolC as a biomarker for toxic pollutants in feedstuffs.

A significant risk to the food chain is the presence of noxious pollutants in the feeds of animals whose products are used in human nutrition. Consequently, analytical methods and biosensors have been developed to detect these types of contaminates in feeds. Here we have evaluated whether the expression of TolC, a promiscuous component of several ATP-dependent efflux pumps in E. coli, up-regulated in response to chemical stress, could be a useful biomarker for this aim. Changes in TolC expression in response to toxic compounds, with different abilities to induce DNA damage, were determined using two E. coli strains with (DH5α) and without (BL21(DE3)) inactivating mutation in RecA gene. Deoxycholic acid and potassium dichromate up-regulated TolC in both strains. In contrast, cisplatin-induced TolC up-regulation was abolished in the absence of a functional RecA. When the effect of several insecticides, herbicides, antibiotics and common soil pollutants on TolC expression was analyzed, a relationship between toxicity and their ability to up-regulate TolC was observed. However, this was not a general event because the insecticide α-cipermetrin induced a reduction in cell viability, which was not accompanied by TolC up-regulation. In contrast, the soil pollutant benzene was able to stimulate TolC expression at non-toxic concentrations. When this test was used to analyze aqueous extracts from different feedstuffs, up-regulation of TolC was found in the absence of cell toxicity and was even accompanied by enhanced cell viability. In conclusion, TolC expression is partly dependent on the integrity of the RecA/LexaA system. Although toxic compounds up-regulate TolC in a dose-dependent manner, this response is also activated by non-toxic agents. Thus, owing to its poor specificity regardless of its sensitivity, the use of TolC up-regulation in E. coli to detect the presence of toxic pollutants in conventional and unconventional sources of nutrients for ruminant feeding requires supplementary biomarkers.

Melatonin pre-treatment mitigates SHSY-5Y cells against oxaliplatin induced mitochondrial stress and apoptotic cell death.

Oxaliplatin (Oxa) treatment to SH-SY5Y human neuroblastoma cells has been shown by previous studies to induce oxidative stress, which in turn modulates intracellular signaling cascades resulting in cell death. While this phenomenon of Oxa-induced neurotoxicity is known, the underlying mechanisms involved in this cell death cascade must be clarified. Moreover, there is still little known regarding the roles of neuronal mitochondria and cytosolic compartments in mediating Oxa-induced neurotoxicity. With a better grasp of the mechanisms driving neurotoxicity in Oxa-treated SH-SY5Y cells, we can then identify certain pathways to target in protecting against neurotoxic cell damage. Therefore, the purpose of this study was to determine whether one such agent, melatonin (Mel), could confer protection against Oxa-induced neurotoxicity in SH-SY5Y cells. Results from the present study found Oxa to significantly reduce SH-SY5Y cell viability in a dose-dependent manner. Alternatively, we found Mel pre-treatment to SH-SY5Y cells to attenuate Oxa-induced toxicity, resulting in a markedly increased cell viability. Mel exerted its protective effects by regulating reactive oxygen species (ROS) production and reducing superoxide radicals inside Oxa-exposed. In addition, we observed pre-treatment with Mel to rescue Oxa-treated cells by protecting mitochondria. As Oxa-treatment alone decreases mitochondrial membrane potential (Δψm), resulting in an altered Bcl-2/Bax ratio and release of sequestered cytochrome c, so Mel was shown to inhibit these pathways. Mel was also found to inhibit proteolytic activation of caspase 3, inactivation of Poly (ADP Ribose) polymerase, and DNA damage, thereby allowing SH-SY5Y cells to resist apoptotic cell death. Collectively, our results suggest a role for melatonin in reducing Oxa induced neurotoxicity. Further studies exploring melatonin's protective effects may prove successful in eliciting pathways to further alter the neurotoxic pathways of platinum compounds in cancer treatment.

Synthesis and Biological Evaluation of Novel Neuroprotective Pyridazine Derivatives as Excitatory Amino Acid Transporter 2 (EAAT2) Activators.

LDN-212320 (3) was found to be a potent EAAT2 activator at a translational level, restoring the normal clearance of glutamate and providing neuronal protection. Since the pharmacologic activation of EAAT2 represents a valuable strategy to relieve neuropathic pain, we synthesized novel activators (4a-f) of EAAT2. Among them 4f, analyzed in comparison with 3 by different paradigms in a rat model of oxaliplatin-induced neuropathic pain, showed the better antihypersensitive profile being able to fully counteract the oxaliplatin-induced neuropathy.

Effects of Hypericum perforatum extract on oxaliplatin-induced neurotoxicity: in vitro evaluations.

Hypericum perforatum L. has been used for centuries as a natural remedy for the treatment of many disorders. Neuropathic pain is a common side effect of oxaliplatin-based chemotherapy and often the cause of therapy discontinuation. Thanks to its anti-inflammatory and analgesic effects, the use of H. perforatum may be a novel therapeutic strategy for neuropathy. The aim of this paper was to evaluate the effect of H. perforatum hydrophilic extract on an in vitro model of oxaliplatin-induced neurotoxicity. The antioxidant potential of extract was first evaluated in cell-free models by the thiobarbituric acid-reactive substances assay and nitro blue tetrazolium oxidation test; the ability of H. perforatum extract to reduce oxaliplatin-induced caspase-3 activity in rat astrocytes and its potential interference with the cytotoxic effects of oxaliplatin in a colorectal cancer in vitro model (HT-29 cells) were also evaluated. The extract showed a significant antioxidant effect and was able to reduce caspase-3 activity in rat astrocytes. Of note, the extract alone exerted a cytotoxic effect in HT-29 cells and did not reduce the cytotoxicity of oxaliplatin in HT-29 cells. These data suggest that H. perforatum could be used as a novel therapeutic strategy for counteracting chemotherapy-induced neuropathy.

Cytotoxic effects of Urtica dioica radix on human colon (HT29) and gastric (MKN45) cancer cells mediated through oxidative and apoptotic mechanisms.

Defects in the apoptotic pathways are responsible for both the colorectal cancer pathogenesis and resistance to therapy. In this study, we examined the level of cellular oxidants, cytotoxicity and apoptosis induced by hydroalcoholic extract of U. dioica radix (0-2000 µg/mL) and oxaliplatin (0-1000 µg/mL, as positive control) in human gastric (MKN45) and colon (HT29) cancer, as well as normal human foreskin fibroblast (HFF) cells. Exposure to U. dioica or oxaliplatin showed a concentration dependent suppression in cell survival with IC50 values of 24.7, 249.9 and 857.5 µg/mL for HT29, MKN45 and HFF cells after 72 h treatment, respectively. ROS formation and lipid peroxidation were also concentration-dependently increased following treatment with U. dioica, similar to oxaliplatin. In addition, the number of apoptotic cells significantly increased concomitantly with concentration of U. dioica as compared with control cells, which is similar to oxaliplatin and serum-deprived cancer cells. In conclusion, the present study demonstrated that U. dioica inhibited proliferation of gastric and colorectal cancer cells while posing no significant toxic effect on normal cells. U. dioica not only increased levels of oxidants, but also induced concomitant increase of apoptosis. The precise signaling pathway by which U. dioica induce apoptosis needs further research.

Aqueous extract of Lithospermi radix attenuates oxaliplatin-induced neurotoxicity in both in vitro and in vivo models.

BACKGROUND: Oxaliplatin can induce peripheral neuropathy (OXIPN) as an adverse side effect in cancer patients. Until now, no effective preventive or therapeutic drug has been developed; therefore, the dose-limiting factor of OXIPN is still an obstacle in the use of oxaliplatin to treat cancer patients. In the present study, we report for the first time that the aqueous extract of Lithospermi radix (WLR) can attenuate the OXIPN in both in vitro and in vivo neuropathic models. METHODS: The protective effect of WLR on OXIPN was evaluated in vitro by quantifying nerve growth factor (NGF)-stimulated neurite outgrowth in PC12 cells treated with a combination of oxaliplatin and WLR. The neuroprotective potential of WLR was further confirmed by measuring the changes in nociceptive sensitivities to external mechanical stimuli in neuropathic animals induced by oxaliplatin. Histological and immunohistochemical studies were further done to examine the effect of WLR in mouse spinal cords and footpads. RESULTS: Oxaliplatin-induced neurotoxicity in NGF-stimulated PC12 cells. It could reduce the lengths and branching numbers of neuritis in NGF-stimulated PC12 cells. Co-treatment of WLR rescued the differentiated PC12 cells from the neurotoxicity of oxaliplatin. In a chronic OXIPN animal model, administration of oxaliplatin i.p. induced enhanced nociceptive sensitivity to mechanical stimuli (25.0 to 72.5 % of response rate) along with spinal activation of microglias and astrocytes and loss of intraepidermal nerve fibers in footpads, which is remarkably suppressed by oral administration of WLR (67.5 to 35 % of response rate at the end of experiment). Cytotoxicity of oxaliplatin determined in human cancer cells was not affected irrespective of the presence of WLR. CONCLUSIONS: In conclusion, we demonstrated that WLR can attenuate OXIPN in both in vitro and in vivo experimental models, which may be in part attributed to its anti-inflammatory activity in the spinal cord and its neuroprotective potential in the peripheral nerve system without affecting the anti-tumor potential of oxaliplatin. Therefore, WLR could be considered as a good starting material to develop a novel therapeutic agent targeting OXIPN. However, further studies should be done to elucidate the underlying mechanism such as molecular targets and active constituent(s) in WLR with neuroprotective potential.

Processed aconite root and its active ingredient neoline may alleviate oxaliplatin-induced peripheral neuropathic pain.

ETHNOPHARMACOLOGICAL RELEVANCE: Processed aconite root (PA, the root of Aconitum carmichaeli, Ranunculaceae) is a crude drug used in traditional Chinese or Japanese kampo medicine to generate heat in the body and to treat pain associated with coldness. Oxaliplatin (L-OHP) is a platinum-based anticancer drug that frequently causes acute and chronic peripheral neuropathies, including cold and mechanical hyperalgesia. AIM OF THE STUDY: We investigated the effects of PA on L-OHP-induced peripheral neuropathies and identified the active ingredient within PA extract. MATERIALS AND METHODS: L-OHP was intraperitoneally injected into mice, and PA boiled water extract was orally administered. Cold and mechanical hyperalgesia were evaluated using the acetone test and the von Frey filament method, respectively. Dorsal root ganglion (DRG) neurons were isolated from normal mice and cultured with L-OHP with or without PA extract. Cell viability and neurite elongation were evaluated. RESULTS: PA extract significantly attenuated cold and mechanical hyperalgesia induced by L-OHP in mice. In cultured DRG neurons, L-OHP reduced cell viability and neurite elongation in a dose-dependent manner. Treatment with PA extract significantly alleviated the L-OHP-induced reduction of neurite elongation, while the cytotoxicity of L-OHP was not affected. Using activity-guided fractionation, we isolated neoline from PA extract as the active ingredient. Neoline significantly alleviated L-OHP-induced reduction of neurite elongation in cultured DRG neurons in a concentration-dependent manner. Moreover, subcutaneous injection of neoline attenuated cold and mechanical hyperalgesia in L-OHP-treated mice. PA extract and neoline did not show sedation and motor impairment. CONCLUSIONS: The present study indicates that PA and its active ingredient neoline are promising agents to alleviate L-OHP-induced neuropathic pain.

Neuroprotective activities of curcumin and quercetin with potential relevance to mitochondrial dysfunction induced by oxaliplatin.

Peripheral neurotoxicity is one of the serious dose-limiting side effects of oxaliplatin (Oxa) when used in the treatment of malignant conditions. It is documented that it elicits major side effects specifically neurotoxicity due to oxidative stress forcing the patients to limit its clinical use in long-term treatment. Oxidative stress has been proven to be involved in Oxa-induced toxicity including neurotoxicity. The mitochondria have recently emerged as targets for anticancer drugs in various kinds of toxicity including neurotoxicity that can lead to neoplastic disease. However, there is paucity of literature involving the role of the mitochondria in mediating Oxa-induced neurotoxicity and its underlying mechanism is still debatable. The purpose of this study was to investigate the dose-dependent damage caused by Oxa on isolated brain mitochondria under in vitro conditions. The study was also designed to investigate the neuroprotective effects of nutraceuticals, curcumin (CMN), and quercetin (QR) on Oxa-induced mitochondrial oxidative stress and respiratory chain complexes in the brain of rats. Oxidative stress biomarkers, levels of nonenzymatic antioxidants, activities of enzymatic antioxidants, and mitochondrial complexes were evaluated against the neurotoxicity induced by Oxa. Pretreatment with CMN and QR significantly replenished the mitochondrial lipid peroxidation levels and protein carbonyl content induced by Oxa. CMN and QR ameliorated altered nonenzymatic and enzymatic antioxidants and complex enzymes of mitochondria. We conclude that CMN and QR, by attenuating oxidative stress as evident by mitochondrial dysfunction, hold promise as agents that can potentially reduce Oxa-induced adverse effects in the brain.

Acute toxic and genotoxic activities of widely used cytostatic drugs in higher plants: Possible impact on the environment.

Cytostatic drugs are highly toxic pharmaceuticals and it was repeatedly postulated that they may cause adverse effects in ecosystems. The acute toxic and genotoxic properties of these drugs have not been adequately investigated in higher plants so far; therefore, we studied the most widely used drugs (5-flurouracil, 5FU; etoposide, Et; cisplatin, CisPt; carboplatin, CaPt; vincristine sulfate, VinS and cyclophosphamide monohydrate, CP) in micronucleus (MN) assays with meiotic pollen tetrad cells of Tradescantia and with root cells from Allium cepa. MNi are formed as a consequence of chromosome breaks and aneuploidy. We monitored also the acute toxic properties of the drugs, i.e. inhibition of cell division (mitotic indices and retardation of root growth) in the latter species. All compounds caused in both indicator plants genotoxic effects. The order of genotoxic potencies expressed as NOELs in µM was CisPt (0.1)≥ Et (0.5)>CP (1.0)>CaPt (10)>5FU (30)>VinS (100) in Tradescantia. A similar order was seen in Allium MN but Et was less active (5.0µM). Four compounds caused alterations of the mitotic indices under the present conditions namely CisPt (0.5), Et (10.0), 5FU (10.0) and VinS (100). Inhibition of root growth decreased in the order CisPt (0.5)>Et (1.0)≥VinS (1.0)>5FU (5.0)>CaPt (33.0)>CP (>1000). Comparisons of the NOELs with the predicted environmental concentrations (PEC) show that the latter values are at least 5 orders of magnitude lower and indicate that it is unlikely that their release in the environment may cause adverse effects in higher plants. However, it is notable that the levels of both platinum compounds and of 5FU in hospital effluents may reach levels which may induce damage of the genetic material.

Role of the TREK2 potassium channel in cold and warm thermosensation and in pain perception.

Two-pore domain background K(+) channels (K2p or KCNK) produce hyperpolarizing currents that control cell membrane polarity and neuronal excitability throughout the nervous system. The TREK2 channel as well as the related TREK1 and TRAAK channels are mechanical-, thermal- and lipid-gated channels that share many regulatory properties. TREK2 is one of the major background channels expressed in rodent nociceptive neurons of the dorsal root ganglia that innervate the skin and deep body tissues, but its role in somatosensory perception and nociception has remained poorly understood. We now report that TREK2 is a regulatory channel that controls the perception of non aversive warm, between 40°C and 46°C, and moderate ambient cool temperatures, between 20°C and 25°C, in mice. TREK2 controls the firing activity of peripheral sensory C-fibers in response to changes in temperature. The role of TREK2 in thermosensation is different from that of TREK1 and TRAAK channels; rather, TREK2, TREK1, and TRAAK channels appear to have complementary roles in thermosensation. TREK2 is also involved in mechanical pain perception and in osmotic pain after sensitization by prostaglandin E2. TREK2 is involved in the cold allodynia that characterizes the neuropathy commonly associated with treatments with the anticancer drug oxaliplatin. These results suggest that positive modulation of the TREK2 channel may have beneficial analgesic effects in these neuropathic conditions.

Spongean alkaloids protect rat kidney cells against cisplatin-induced cytotoxicity.

Nephrotoxicity is the major dose-limiting adverse effect of cisplatin (CisPt) and results from CisPt-induced damage of tubular cells. Nephroprotective strategies are preferential to improve supportive care in cancer. We investigated a subset of purified substances originating from various plants or from marine sponges as to their potency to protect rat renal tubular cells (NRK-52E) against the cytotoxic and genotoxic effects of cisplatin. Cotreatment with a substance pool containing five purified substances originating from marine sponges increased the viability of NRK-52E cells following cisplatin treatment. Cytoprotection was accompanied by a reduced level of DNA damage as indicated by a lower amount of S139 phosphorylated histone H2AX (γH2AX) 24 h after treatment. Cytoprotection and genoprotection by the sponge substance pool did not comprise the anthracycline derivative doxorubicin. The spongean alkaloid aaptamine was identified as major bioactive compound that mediates cisplatin resistance. Aeroplysinin-1 was less cytoprotective than aaptamine. Notably, aaptamine preferentially conferred resistance to cisplatin, but not to oxaliplatin. Cytoprotection by aaptamine was also observed in rat glomerular endothelial cells, but not in RT-112 bladder cancer cells. Protection by aaptamine does not rest on a reduced formation of DNA damage caused by cisplatin treatment. Aaptamine and aeroplysinin-1 affected cisplatin-stimulated DDR as reflected on the level of S15-phosphorlyated p53 and S345-phosphorylated checkpoint kinase-1. Summarizing, the spongean alkaloid aaptamine alleviates cisplatin-induced damage in tubular and glomerular rat kidney cells. Therefore, we hypothesize that aaptamine might be useful to widen the therapeutic window of a cisplatin-based therapeutic regimen.

Involvement of α7 nAChR subtype in rat oxaliplatin-induced neuropathy: effects of selective activation.

Oxaliplatin, unlike other platinum anticancer agents, has only mild toxic effects on the hematopoietic, urinary and gastrointestinal systems. Its dose-limiting side effect is neurotoxicity that may evolve to a neuropathic syndrome which is difficult to treat. In this study we treated rats with oxaliplatin (2.4 mg/kg/day intraperitoneally, for 3 weeks), and observed that expression levels of the α7 nicotinic acetylcholine receptor (nAChR) subunit were dramatically decreased both in the peripheral and central nervous system. The repeated administration (30 mg/kg/day per os, for 3 weeks) of (R)-ICH3, the most active enantiomer of a novel α7 nAChR agonist, and of PNU-282987 prevented the receptor down-regulation. On the other hand, both agonists per se up-regulated the α7 nAChR subunit compared to control. (R)-ICH3 and PNU-282987 significantly reduced oxaliplatin-dependent alterations of the pain threshold when noxious or non-noxious stimuli were used. Further ex vivo analysis highlighted their neuroprotective effects in dorsal root ganglia and peripheral nerves. The two agonists did not prevent the increase in microglia cell number induced by oxaliplatin in the central nervous system. Astrocyte density was enhanced by the agonist treatment in the spinal cord, thalamus and somatosensory area 1 as opposed to the effects of oxaliplatin treatment. (R)-ICH3 and PNU-282987 per se increased glial cell number in a region-specific manner. In summary, α7 nAChR is involved in oxaliplatin-dependent neuropathology and the agonists (R)-ICH3 and PNU-282987 reduce pain and protect nervous tissue with concomitant glial activation. Since glial cells play a role both in pain and in neuroprotection, an α7 AChR-dependent modulation of glial functions is suggested to distinguish rescue signals from the pathological pain-mediating pathway.

Oxaliplatin-induced oxidative stress in nervous system-derived cellular models: could it correlate with in vivo neuropathy?

Oxaliplatin is a platinum-organic drug with antineoplastic properties used for colorectal cancer. With respect to the other platinum derivates oxaliplatin induces only a mild hematological and gastrointestinal toxicity. Its limiting side effect is its neurotoxicity, which results in a sensory neuropathy. Repeated oxaliplatin treatment in the rat led to a neuropathic pain characterized by a significant oxidative damage throughout the nervous system. The natural antioxidants silibinin and α-tocopherol reduce redox alteration and prevent pain. Starting from the "oxidative hypothesis" as a molecular basis of chemotherapy-induced neurotoxicity, we decided to explore deep inside the mechanisms of oxaliplatin neurotoxicity and search for a cellular system useful for screening antioxidant compounds that can reduce oxaliplatin neurotoxicity. Focusing on various constituents of the central nervous system, we used the neuronal-derived cell line SH-SY5Y and primary cultures of rat cortical astrocytes. Oxaliplatin significantly increased superoxide anion production and induced lipid peroxidation (malonyldialdehyde levels) and protein (carbonylated proteins) and DNA oxidation (8-OH-dG levels). Silibinin and α-tocopherol (10µM) were able to reduce the oxidative damage in both cell types. These antioxidants fully protected astrocytes from the caspase 3 apoptotic signaling activation induced by oxaliplatin. The damage prevention effects of silibinin and α-tocopherol on nervous system-derived cells did not interfere with the oxaliplatin antineoplastic in vitro mechanism as evaluated on a human colon adenocarcinoma cell line (HT29). Moreover, neither silibinin nor α-tocopherol modified the oxaliplatin-induced apoptosis in HT29 cells, suggesting a different antiapoptotic profile in normal vs tumoral cells for these antioxidant compounds. In conclusion, because data obtained in in vitro cellular models parallel the in vivo study we propose cell models to investigate oxaliplatin neurotoxicity and to screen possible therapeutic adjuvant agents.

Evaluation of effects of copper histidine on copper transporter 1-mediated accumulation of platinum and oxaliplatin-induced neurotoxicity in vitro and in vivo.

The purpose of the present study was to determine whether copper histidine could inhibit copper transporter 1 (Ctr1)-mediated transport of oxaliplatin in vitro and thereby limit the accumulation of platinum and neurotoxicity of oxaliplatin in dorsal root ganglion (DRG) tissue in vivo. In HEK293 cells overexpressing rat Ctr1, copper histidine was shown to be transported by Ctr1 and to inhibit their Ctr1-mediated uptake of oxaliplatin. Pilot in vivo dose-finding studies showed that copper histidine at doses up to 2 mg/kg, p.o., daily for 5 days/week could be added to maximum tolerated doses of oxaliplatin (1.85 mg/kg, i.p., twice weekly) for 8 week combination treatment studies in female Wistar rats. After treatment, rats showed significant changes in sensory neuron size profiles in DRG tissue induced by oxaliplatin that were not altered by its coadministration with copper histidine. The expression of copper transporters (Ctr1 and copper-transporting P-type ATPase 1 (Atp7a)) in DRG tissue appeared unchanged following treatment with oxaliplatin given alone or with copper histidine. Platinum and copper tissue levels were higher in DRG than in most other tissues, but were unaltered by the addition of copper histidine to oxaliplatin treatment. In conclusion, copper histidine inhibited cellular uptake of oxaliplatin mediated by Ctr1 in vitro without altering the accumulation of platinum or neurotoxicity of oxaliplatin in DRG tissue in vivo at doses tolerated in combination with oxaliplatin treatment.

Pathogenesis of FOLFOX induced sinusoidal obstruction syndrome in a murine chemotherapy model.

BACKGROUND & AIMS: Sinusoidal obstruction syndrome (SOS) following oxaliplatin based chemotherapy can have a significant impact on post-operative outcome following resection of colorectal liver metastases. To date no relevant experimental models of oxaliplatin induced SOS have been described. The aim of this project was to establish a rodent model which could be utilised to investigate mechanisms underlying SOS to aid the development of therapeutic strategies. METHODS: C57Bl/6 mice, maintained on a purified diet, were treated with intra-peritoneal FOLFOX (n=10), or vehicle (n=10), weekly for five weeks and culled one week following final treatment. Sections of the liver and spleen were fixed in formalin and paraffin embedded for histological analysis. The role of oxidative stress on experimental-induced SOS was determined by dietary supplementation with butylated hydroxyanisole and N-acetylcysteine. RESULTS: FOLFOX treatment was associated with the development of sinusoidal dilatation and hepatocyte atrophy on H&E stained sections of the liver in keeping with SOS. Immunohistochemistry for p21 demonstrated the presence of replicative senescence within the sinusoidal endothelium. FOLFOX induced endothelial damage leads to a pro-thrombotic state within the liver associated with upregulation of PAI-1 (p<0.001), vWF (p<0.01) and Factor X (p<0.001), which may contribute to the propagation of liver injury. Dietary supplementation with the antioxidant BHA prevented the development of significant SOS. CONCLUSIONS: We have developed the first reproducible model of chemotherapy induced SOS that reflects the pathogenesis of this disease in patients. It appears that the use of antioxidants alongside oxaliplatin based chemotherapy may be of value in preventing the development of SOS in patients with colorectal liver metastases.

Pulmonary toxicity with oxaliplatin and capecitabine/5-Fluorouracil chemotherapy: a case report and review of the literature.

BACKGROUND: Oxaliplatin in combination with either 5-fluorouracil or capecitabine is commonly used in the treatment of colorectal cancer and is rarely associated with pulmonary toxicity. This is the first reported case of oxaliplatin and capecitabine/5-fluorouracil causing pulmonary toxicity in a patient with pre-existing asymptomatic interstitial lung disease. CASE REPORT: We report a case of a man who was treated with oxaliplatin and capecitabine for 1 cycle, then subsequently with oxaliplatin and 5-fluorouracil following a resected Dukes' C colon carcinoma. His preoperative computed tomography scan incidentally showed mild pulmonary interstitial changes for which he was asymptomatic. He developed pulmonary fibrosis during the course of his chemotherapy, and therefore further chemotherapy was stopped. He was treated with high dose steroids and immunosuppressants which initially stabilized his respiratory symptoms. CONCLUSIONS: Pulmonary fibrosis is a rare complication of oxaliplatin and capecitabine/5-fluorouracil. With the widespread use of oxaliplatin combinations in colorectal cancer, active assessment for interstitial lung disease is recommended and caution in its use should be exercised in those with pre-existing interstitial lung disease.

Structure, solution chemistry, antiproliferative actions and protein binding properties of non-conventional platinum(II) compounds with sulfur and phosphorus donors.

Twelve Pt(II) complexes with cis-PtP(2)S(2) pharmacophores (where P(2) refers to two monodentate or one bidentate phosphane ligand and S(2) is a dithiolato ligand) were prepared, characterized and evaluated as potential antiproliferative agents. The various compounds were first studied from the structural point of view; afterward, their solubility properties as well as their solution behaviour were analyzed in detail. Antiproliferative properties were specifically evaluated against A2780 human ovarian carcinoma cells, either resistant or sensitive to cisplatin. For comparison purposes similar studies were carried out on four parent cis-dichloro bisphosphane Pt(II)complexes. On the whole, the cis-PtP(2)S(2) compounds displayed significant antiproliferative properties while the cis-PtP(2)Cl(2) (cis-dichloro bisphosphane Pt(II)) compounds revealed quite poor biological performances. To gain further insight into the molecular mechanisms of these bisphosphane Pt(II) compounds, the reactions of selected complexes against the model protein cytochrome c were investigated by ESI-MS and their adduct formation explored. A relevant reactivity with cyt c was obtained only for cis-PtP(2)Cl(2) compounds, whereas cis-PtP(2)S(2) compounds turned out to be nearly unreactive. The obtained results are interpreted and discussed in the frame of the current knowledge of anticancer platinum compounds and their structure-activity-relationships. The observation of appreciable antiproliferative effects for the relatively inert cis-PtP(2)S(2) compounds strongly suggests that these compounds will undergo specific activation within the cellular environment.

Pyridoxine to protect from oxaliplatin-induced neurotoxicity without compromising antitumour effect.

PURPOSE: Oxaliplatin (OHP) in combination with 5-fluorouracil/leucovorin (FOLFOX) is clinically used as frontline therapy in patients with advanced colorectal carcinoma (CRC), with response rates ranging from 46 to 71%. This combination is now considered a standard treatment for metastatic CRC and also in the post-operative adjuvant setting. Reversible, cumulative, peripheral sensory neuropathy is the principal dose-limiting toxicity of OHP therapy. Pyridoxine (vitamin B6) has been shown to reduce cisplatin and fluoropyrimidine-related neurotoxicity but its administration with OHP has not yet been studied. Low doses of pyridoxine are free of side effects; it can be given orally. If pyridoxine administration with oxaliplatin has no adverse effect on OHP cytotoxicity effects, it will be a simple and cost-effective way to minimise OHP-induced neurotoxicity. METHODS: In vitro simultaneous combination of OHP and pyridoxine was studied in 6 CRC cell lines (HT29, Widr, SW480, HCT116, H630 and SW1116), in an ovarian cancer cell line (A2780) and its cisplatin-resistant subline (ADDP) and in an oestrogen-dependent breast cancer cell line (MCF-7). Three fixed concentrations of pyridoxine: 1, 10 and 25 µM were combined with varying concentrations of OHP, and the growth inhibitory effects were evaluated using the MTT cell growth assay. RESULTS: Oxaliplatin induced consistent cytotoxicity in all cell lines with GI(50) values between 0.23 and 7.6 µM. Addition of pyridoxine at concentrations of 1-25 µM does not affect OHP cytotoxicity. CONCLUSIONS: Administration of pyridoxine, at concentrations extending across possible therapeutic plasma levels in humans, does not antagonise OHP antitumour effects in a range of relevant tumour cell lines. This study provides a foundation for clinical studies to test whether pyridoxine can minimise OHP-related neurotoxicity, and clinicians can be confident that pyridoxine is very unlikely to reverse the antitumour effects of OHP, as seems to be the case with Ca/Mg infusions. This could prove to be a cost-effective way to minimise OHP-related neurotoxicity, allowing more effective less toxic treatment and better outcomes in patients.

Efficacy and safety of irinotecan-based chemotherapy for advanced colorectal cancer outside clinical trials: an observational study.

BACKGROUND: This prospective observational study in typical community-based outpatient clinics evaluated the efficacy and toxicity of weekly and biweekly irinotecan-based chemotherapies and their compatibility depending on age. METHODS: 601 patients with advanced or metastatic colorectal cancer receiving first-, second-, or third-line irinotecan-based therapy were regularly analyzed for response and toxicity until the end of therapy. RESULTS: The median age was 65 (28-87) years, approximately one-third of the patients were ≥70 years old. Of all patients, 405 were treated weekly and 68 biweekly. Median overall survival (OS) for first-line therapy was 26.5 months for the <70-year-old patients and 19.4 months for the ≥70-year-old patients. Toxicities were moderate in all groups. Tumor growth control rates (TCR) and median time to progression (TTP) were marginally better for patients <70 years old. Median TTP was 9.9 months in first-line therapy, 9.8 months after adjuvant therapy, 7.7 months in second-line, and 6.4 months in third-line therapy. CONCLUSIONS: Toxicity and response data from this observational study clearly confirm the positive results from previous clinical studies and show a slight ad-vantage in efficacy for the <70-year-old patients.

NGF protects dorsal root ganglion neurons from oxaliplatin by modulating JNK/Sapk and ERK1/2.

The involvement of the Mitogen-Activated Protein Kinases (MAPKs) family in platinum derivative-induced peripheral neuropathy has already been demonstrated. In particular, it has been evidenced that in Dorsal Root Ganglion (DRG) neurons prolonged exposure to oxaliplatin (OHP) induces early activation of p38 and ERK1/2, which mediate neuronal apoptosis, while the neuroprotective action of JNK/Sapk is downregulated by the drug treatment. In this study, the exposure of OHP-treated neurons to a neuroprotective stimulus, represented by a high dose of NGF, counteracts OHP-induced neuronal mortality. This effect was achieved by restoring the MAPK activation existing in untreated control cells. Increased viability occurred also after the administration of retinoic acid (RA), a pro-differentiative agent able to activate both JNK/Sapk and ERK1/2. The use of specific chemical inhibitors of MAPKs confirms the importance of this class of proteins for the neuroprotective pathway, since they reverse the protective effect. In summary, our findings assess the validity of MAPKs as the target of neuroprotective therapies during chemotherapeutic treatment. Moreover they also describe a double role for ERK1/2, depending on cellular stimulation, since it mediates neuronal apoptosis after OHP exposure. However, it is also important, as is JNK/Sapk, in preserving the correct cellular differentiation that is pivotal for neuronal survival.