Multitarget Hybrid Fasudil Derivatives as a New Approach to the Potential Treatment of Amyotrophic Lateral Sclerosis.

Hybrid compounds containing structural fragments of the Rho kinase inhibitor fasudil and the NRF2 inducers caffeic and ferulic acids were designed with the aid of docking and molecular mechanics studies. Following the synthesis of the compounds using a peptide-coupling methodology, they were characterized for their ROCK2 inhibition, radical scavenging, effects on cell viability (MTT assay), and NRF2 induction (luciferase assay). One of the compounds (1d) was selected in view of its good multitarget profile and good tolerability. It was able to induce the NRF2 signature, promoting the expression of the antioxidant response enzymes HO-1 and NQO1, via a KEAP1-dependent mechanism. Analysis of mRNA and protein levels of the NRF2 pathway showed that 1d induced the NRF2 signature in control and SOD1-ALS lymphoblasts but not in sALS, where it was already increased in the basal state. These results show the therapeutic potential of this compound, especially for ALS patients with a SOD1 mutation.

Red Beetroot's NMR-Based Metabolomics: Phytochemical Profile Related to Development Time and Production Year.

Red beetroot (RB) is a well-known health-promoting food consumed worldwide. RB is commonly used in food processing and manufacturing thanks to the high content of components that can also be employed as natural coloring agents. These bioactive molecules vary their concentration depending on beetroot seasonality, harvest time and climate conditions. The first objective of this study was to evaluate the variation of the RB phytochemical profile related to the root development during three different harvest times, using an 1H-NMR-based metabolomic approach. Changes of carbohydrates and secondary metabolite concentrations were observed from July to September. Secondly, we compared the metabolic profiles of the final processed beet juices in three different production years to observe the effect of climate conditions on the RB's final product metabotype. A PCA analysis performed on juice extracts showed that production years 2016 and 2017 were characterized by a high content of choline and betaine, while 2018 by a high content of amino acids and dopamine and a low content of inorganic nitrates. This study suggests that the harvest time and roots growth conditions could be used to modulate the RB phytochemical profile, according to the final requirements of use, food or coloring agent source.

New short strategy for the synthesis of the dibenz[b,f]oxepin scaffold.

In this report a short and efficient synthesis of the dibenz[b,f]oxepin framework through intramolecular SNAr and McMurry reactions is described. The diaryl ethers required for the McMurry reaction have been obtained in good yields under microwave-assisted conditions of the reaction of salicylaldehydes with fluorobenzaldehydes without catalysts. Application of an intramolecular McMurry reaction to the synthesized diarylethers using TiCl4/Zn in THF gave the target dibenzo[b,f]oxepin system in 53%-55% yields.

A one-pot sequence for the efficient synthesis of highly functionalized macrocarbocycles or bridged 2,8-dioxabicyclo[3.2.1]octanes from 1-nitrobicyclic compounds.

The reaction of 1-nitrobicyclo[n.3.1]alkane-(6 + n)ones with sodium borohydride followed by acidic workup led to ring opening via a one-pot sequence comprising the retro-Dieckmann-type opening of the α-nitroketone structural fragment, followed by aldehyde reduction and a final Nef reaction, leading to highly functionalized 12 to 14-membered carbocyclic ketones bearing three stereocenters, which are adjacent in some of the compounds. The reactions starting from 1-nitrobicyclo[9.3.1]pentadecan-15-ones could be adjusted to give macrocyclic 2,8-dioxabicyclo[3.2.1]octanes containing an additional bridge by diastereoselective formation of a third ring and a fourth stereocenter through acid-promoted intramolecular ketal formation. This is a very interesting ring system related to the core of the zaragozic acid family of natural products.

Domino reactions for the synthesis of bridged bicyclic frameworks: fast access to bicyclo[n.3.1]alkanes.

In the current bid for synthetic efficiency, multiple bond-forming transformations are becoming a key concept in organic synthesis. In this context, domino protocols have become increasingly common in the synthesis of bicyclic systems. This tutorial review aims at providing a short but authoritative overview of this topic, focusing on the preparation of bridged bicyclo[n.3.1]alkane systems, and is organized according to the number of rings created in the key domino process.

Synthesis of benzo- and naphtho-fused bicyclo[n.3.1]alkane frameworks with a bridgehead nitrogen function by palladium-catalyzed intramolecular α'-arylation of α-nitroketones.

The C-alkylation of cyclic α-nitroketones with α-halobenzyl halides in the presence of DBU followed by a Pd-catalyzed intramolecular C-arylation afforded benzo-and naphtho-fused bicyclo[n.3.1]alkane derivatives (n = 3, 4, 5) in excellent overall yields for the two-step sequence. In some of the reactions starting from α-nitrocyclooctanone, the major products were fused indane derivatives arising from an intramolecular attack of an intermediate Pd species onto the carbonyl group, followed by elimination.

Domperidone and long QT syndrome.

Domperidone is a prokinetic agent widely prescribed in adults and children with gastrointestinal disorders. Recently several Regulatory Agencies published safety information on the risk of long QT syndrome associated with the use of domperidone. We conducted a literature review using PubMed (1966 - Jan 2010) with the aim to locate articles on ventricular arrhytmias, Sudden Cardiac Death (SCD), long QT syndrome and Torsade de Pointes (TdP) following domperidone administration. Twenty-two papers were included in the review: three studies in vitro models, one animal study, five case reports/series, twelve clinical studies and one editorial. In vitro studies demonstrated cardiac electrophysiological effects of domperidone on the rapid component of the cardiac delayed rectifier K(+) current (I(Kr)) through the blockade of channels encoded by the Human Ether-a-go-go Related Gene (HERG). A total of fourteen cases of cardiotoxicity following intravenous (12 cases) or oral (2 cases) domperidone administration from case reports/series were identified. A case - control study, performed on a general practice observational database reported an OR: 3.8 (95% CI: 1.5-9.7) for SCD after domperidone exposure. Prescribers and other healthcare professionals should take into account the risk of QT syndrome in domperidone users and avoid administering domperidone in patients concomitantly taking strong CYP3A4 inhibitors or other QT prolonging drugs.

Enzymatic-nonenzymatic cellular antioxidant defense systems response and immunohistochemical detection of MDMA, VMAT2, HSP70, and apoptosis as biomarkers for MDMA (Ecstasy) neurotoxicity.

3,4-Methylenedioxymethamphetamine (MDMA)-induced neurotoxicity leads to the formation of quinone metabolities and hydroxyl radicals and then to the production of reactive oxygen species (ROS). We evaluated the effect of a single dose of MDMA (20 mg/kg, i.p.) on the enzymatic and nonenzymatic cellular antioxidant defense system in different areas of rat brain in the early hours (<6 hr) of the administration itself, and we identified the morphological expressions of neurotoxicity induced by MDMA on the vulnerable brain areas in the first 24 hr. The acute administration of MDMA produces a decrease of reduced and oxidized glutathione ratio, and antioxidant enzyme activities were significantly reduced after 3 hr and after 6 hr in frontal cortex. Ascorbic acid levels strongly increased in striatum, hippocampus, and frontal cortex after 3 and 6 hr. High levels of malonaldehyde with respect to control were measured in striatum after 3 and 6 hr and in hippocampus and frontal cortex after 6 hr. An immunohistochemical investigation on the frontal, thalamic, hypothalamic, and striatal areas was performed. A strong positive reaction to the antivesicular monoamine transporter 2 was observed in the frontal section, in the basal ganglia and thalamus. Cortical positivity, located in the most superficial layer was revealed only for heat shock protein 70 after 24 hr.

The efficacy and tolerability of glucosamine sulfate in the treatment of knee osteoarthritis: A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Osteoarthritis (OA) is the most common form of arthritis and is often associated with disability and impaired quality of life. OBJECTIVE: The aim of the study was to assess the efficacy and tolerability of glucosamine sulfate (GS) in the treatment of knee OA. METHODS: Consecutive outpatients affected by primary monolateral or bilateral knee OA were enrolled in this double-blind, double-dummy, prospective, randomized, placebo-controlled trial. One group received GS 1500 mg QD for 12 weeks, and the other group received placebo QD for 12 weeks. The treatment period was followed by a 12-week treatment-free observation phase. Each patient was examined at baseline and at weeks 4, 8, 12, 16, 20, and 24. The primary efficacy criteria were pain at rest and during movement, assessed on a visual analog scale (VAS) of 0 to 100 mm. The secondary criteria included the Western Ontario and McMaster Universities (WOMAC) index for total pain score (W-TPS), total stiffness score (W-TSS), and total physical function score (W-TPFS). VAS, W-TPS, W-TSS, and W-TPFS were evaluated at baseline and at weeks 4, 8, 12, 16, 20, and 24. Analgesic drug consumption (ie, acetaminophen or NSAIDs) was also assessed. RESULTS: Patient demographics were similar in the GS and placebo groups. Of 60 randomized patients (30 per group), 56 completed the study (28 treated with GS and 28 who received placebo). Statistically significant improvements in symptomatic knee OA were observed, as measured by differences in resting pain at weeks 8, 12, and 16 (all, P < 0.05 vs placebo) and in pain during movement at weeks 12 and 16 (both, P < 0.05). W-TPS was lower with GS than placebo at weeks 8, 12, and 16 (all, P < 0.01), and at week 20 (P < 0.05). W-TSS was also lower with GS than placebo at weeks 8, 12, 16, and 20 (all, P < 0.05). W-TPFS was lower with GS than placebo at weeks 8 (P < 0.05), 12 (P < 0.01), 16 (P < 0.05), and 20 (P < 0.05). Drug consumption was lower in the GS group than the placebo group at weeks 8, 12, 16, and 20 (all, P < 0.05). The incidence of adverse events was 36.7% with GS and 40.0% with placebo. CONCLUSIONS: GS 1500 mg QD PO for 12 weeks was associated with statistically significant reductions in pain and improvements in functioning, with decreased analgesic consumption, compared with baseline and placebo in these patients with knee OA. A carryover effect was detected after treatment ended.

Cardiac oxidative stress determination and myocardial morphology after a single ecstasy (MDMA) administration in a rat model.

Experimental and clinical data indicate that 3,4-methylenedioxy-N-methylamphetamine (MDMA) abuse can produce significant cardiovascular toxicity. A mechanism may be a direct toxic effect of redox active metabolites of MDMA. To evaluate the effect of a single MDMA dose on cellular antioxidant defence system and to investigate the morphology in male albino rats, total glutathione (GSH), oxidised glutathione (GSSG), ascorbic acid (AA), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and malondialdehyde (MDAL) were studied. The effects were evaluated at 3, 6, 16 and 24 h after MDMA administration. Antioxidant enzymes activity was significantly reduced: GPx (-24%) and SOD (-50%) after 3 h and GR (-19%) after 6 h from treatment. AA levels decrease (-37%) after 3 h and (-30%) after 6 h; MDAL level increased (+119%) after 3 h; GSH levels decreased after 3 (31.3%) and 6 h (37.9%) from MDMA treatment. GSSG content was not affected by ecstasy administration. Myocardial contraction band necrosis (CBN) was already visible in rats killed at 6 h. After 16 h, macrophagic monocytes around the necrotic myocardial cells were observed, and within 24 h, this infiltrate became more widespread with an early removal of the necrotic material. Calcium deposits were observed within ventricular cardiomyocytes with intact nuclei and sarcomeres. Single administration of MDMA can significantly alter the cellular antioxidant defence system and produce oxidative stress which may result in lipid peroxidation and disruption of Ca(2 +) homeostasis. The depression in Ca(2+) regulatory mechanism by reactive oxygen species ultimately results in intracellular Ca(2 +) overload, CBN and cell death.

Chemotherapeutic drugs may be used to enhance the killing efficacy of human tumor antigen peptide-specific CTLs.

The effects of anticancer chemotherapy on antigen-specific cytotoxic T lymphocytes (CTLs) are mostly unknown. We tested the effects of cytotoxic drugs such as 5-fluorouracil, gemcitabine, and oxaliplatin on the functional activity of antigen-specific CTL cultures derived from the peripheral blood mononuclear cells of human donors. We found that a biweekly drug-exposure of human HLA-A(*)02.01+ CTLs derived from bulk cultures led to completely different effects if occurring early (day second) or late (day thirteenth) after the in vitro stimulations with the cognate peptides. In the first case, there was a significant CTL inhibition, whereas in the second, there was a marked enhancement of the antigen-specific cytolytic activity. Results of immunocytofluorimetric studies and CTL/natural killer inhibition assays suggested that the latter effect could be related to a more selective drug-mediated inhibition of cohabitant T regulatory (reg) cells. These results were translated in an in vivo therapeutic mouse model where humanized HLA-A(*)02.01 transgenic mice inoculated with EL-4/humanized HLA-A(*)02.01 transgenic mice showed a prolonged survival and the greatest rate of cure when receiving a combined treatment with a thymidylate synthase-specific peptide vaccine and a multidrug chemotherapy regimen administered late after immunization. Tumor samples derived from this group of mice showed a reduced expression of the target thymidylate synthase antigen, a marked reduction of T(reg)s, and a noteworthy infiltration of C8+ T cells. These results may have clinical implications for the design of new translational anticancer regimens aimed at combining chemotherapy and immunotherapy.

Correlation between cardiac oxidative stress and myocardial pathology due to acute and chronic norepinephrine administration in rats.

BACKGROUND: To investigate the cardiotoxic role of reactive oxygen species (ROS) and of products derived from catecholamines auto-oxidation, we studied: (1) the response of antioxidant cardiac cellular defence systems to oxidative stress induced by norepinephrine (NE) administration, (2) the effect of NE administration on cardiac beta1-adrenergic receptors by means of receptor binding assay, (3) the cellular morphological alterations related to the biologically cross-talk between the NE administration and cytokines [tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), interleukins IL6, IL8, IL10]. METHODS AND RESULTS: A total of 195 male rats was used in the experiment. All animals underwent electrocardiogram (EKG) before being sacrificed. The results obtained show that NE administration influences the antioxidant cellular defence system significantly increasing glutathione peroxidase (GPx) activity, glutathione reductase (GR) and superoxide dismutase (SOD). The oxidized glutathione (GSH/GSSG) ratio significantly decreases and malondialdehyde (MDA) levels increase showing a state of lipoperoxidation of cardiac tissue. We describe a significant apoptotic process randomly sparse in the damaged myocardium and the effect of ROS on the NE-mediated TNF-alpha, MCP-1, and IL6, IL8, IL10 production. CONCLUSIONS: Our results support the hypothesis that catecholamines may induce oxidative damage through reactive intermediates resulting from their auto-oxidation, irrespective of their interaction with adrenergic receptors, thus representing an important factor in the pathogenesis of catecholamines-induced cardiotoxicity. The rise of the cardioinhibitory cytokines may be interpreted as the adaptive response of jeopardized myocardium with respect to the cardiac dysfunction resulting from NE injection.

Calcium bioavailability from a new calcium-fortified orange beverage, compared with milk, in healthy volunteers.

The recommended dietary calcium intake may be difficult to reach using dairy products only. This study aimed to evaluate the absorbability of calcium of a new orange beverage in comparison with that of milk. Ten healthy adults, 5 males and 5 females, were randomly divided to receive, under fasting conditions, an orange beverage enriched either with calcium or milk. Both the beverages had been labelled the previous evening with a 44Ca solution. After a two-month interval the subjects underwent a crossover of beverages. Total and ionized calcium, parathyroid (PTH) hormone, and 44Ca were evaluated. The 44Ca was measured by inductively coupled plasma spectrometry. The relative changes in calcium absorption from the two test drinks were similar (23.0 +/- 6.4% for milk and 20.9 +/- 9.1% for the orange beverage). No significant differences were found between the two test groups. Both milk and orange beverage determined a similar and significant (p < 0.001) decrease in serum PTH two hours after the beginning of the test (-22.1 +/- 14.0% for milk and -27.9 +/- 15.3% for orange beverage). We can conclude that the bioavailability of calcium from this new calcium-enriched orange beverage is similar to that of milk.

Treatment of peritoneal carcinomatosis by cytoreductive surgery and intraperitoneal hyperthermic chemoperfusion (IHCP): postoperative outcome and risk factors for morbidity.

BACKGROUND: Cytoreductive surgery with limited or extended peritonectomy associated with intraperitoneal hyperthermic chemoperfusion (IHCP) has been proposed for treatment of peritoneal carcinomatosis (PC) from abdominal neoplasms. METHODS: Fifty-nine patients with PC from abdominal neoplasms underwent 61 treatments using this technique from January 2000 to August 2005. Surgical debulking, completed by partial or total peritonectomy, was performed in most cases. In 16 patients with positive peritoneal cytology without macroscopic peritoneal disease, IHCP was performed in order to prevent peritoneal recurrence. IHCP was carried out throughout the abdominopelvic cavity for 60 minutes using a closed abdomen technique. Intra-abdominal temperature ranged between 41 degrees C and 43 degrees C; mitomycin C (25 mg/mq) and cisplatin (100 mg/mq) were the anticancer drugs generally used, and they were administered with a flow rate of 700-800 ml/minute. RESULTS: Mean hospital stay was 13 +/- 7 (range 7-49) days. Postoperative complications occurred in 27 patients (44.3%); of these, major morbidity was observed in 17 (27.9%). The most frequent complications were wound infection (9 cases), grade 2 or greater hematological toxicity (5 cases), intestinal fistula (5 cases), and pleural effusion requiring drainage (5 cases). Reoperation was necessary in 5 patients (8.2%). One patient with multiorgan failure died in the postoperative period (mortality rate: 1.6%). Multivariate analysis of several variables identified completeness of cancer resection (CCR-2/3 vs. CCR-0/1, relative risk: 9.27) and age (relative risk: 1.06 per year) as independent predictors of postoperative morbidity. Preliminary follow-up data indicate that survival probability may be high in patients with ovarian or colorectal cancer and low in patients with gastric cancer. CONCLUSIONS: IHCP combined with cytoreductive surgery involves a high risk of morbidity, but postoperative complications could be resolved favorably in most cases with correct patient selection and adequate postoperative care. Tumor residual and advanced age significantly increase the risk of morbidity after this procedure.

Binding studies for serotoninergic, dopaminergic and noradrenergic receptors of Valeriana adscendens Trel. extracts.

Valeriana adscendens Trel. (Valerianaceae) is a psychoactive plant usually used in magical-therapeutic rituals in traditional practices of the Northern Peruvian Andes. Previous studies have been carried out on extracts of aerial parts in order to validate its traditional use. The results indicated that Valeriana adscendens exerts important effects on the central nervous system. Aim of the present study is to evaluate if the effects on the central nervous system of Valeriana adscendens extracts can be associated with interaction with some CNS receptors. In this work we examined affinity and selectivity of two Valeriana adscendens extracts (methanolic and aqueous) towards 5-HT(1A), 5-HT(2A), 5-HT(2C) serotononergic, D(1) and D(2) dopaminergic, alpha(1) and alpha(2) noradrenergic receptors by a preliminary binding screen. The results show weak affinity to 5-HT(1A) for the aqueous extract. Both extracts showed affinity for D(1) receptors, but only for the methanolic extract the IC(50) value was determinable (30.14 microg/ml). No affinity for 5-HT(2A), 5-HT(2C) serotononergic receptors, alpha(1) and alpha(2) noradrenergic receptors and D(2) receptors was recorded for the extracts.

In vitro antiproliferative effect of six Salvia species on human tumor cell lines.

This study was designed to examine the in vitro antiproliferative activity of the methanol crude extracts of six Salvia species: Salvia dominica L. leaves, Salvia lanigera Desf. aerial parts, Salvia menthaefolia Ten. roots, Salvia palaestina Benth. aerial parts, Salvia sclarea L. roots and Salvia spinosa L. aerial parts. Extracts were screened for their possible antitumoral activity by MTT test on nine human cancer cell lines: glioblastoma (DBTRG-05MG, T98G, U-87MG), colorectal adenocarcinoma (WiDr and HT-29), prostate adenocarcinoma (MDA Pca2b), choriocarcinoma (JEG-3), endometrium adenocarcinoma (HEC-1A) and B lymphoblast (CIR). IC(50) values were determined for only five extracts and ranged from 90 to 400 microg/mL approximately. Salvia menthaefolia extract exhibited marked antiproliferative activity against all tumor cell lines showing lower IC(50) values, while S. spinosa, S. sclarea and S. dominica extracts showed a degree cytotoxic activity dependent on the cell line type. Finally S. palaestina extract revealed a moderate antiproliferative effect only against three cell lines. Salvia lanigera extract displayed toxic activity at all concentrations tested. The results strengthen the evidence that the genus Salvia could be considered a natural resource of potential antitumor agents.

Chemo-immunotherapy of colorectal carcinoma: preclinical rationale and clinical experience.

Advanced colorectal cancer is a common disease with an high mortality rate. For four decades, pharmacological treatment of the advanced disease was based on the use of 5-fluorouracil alone or in combination with biomodulators such as folinic acid and intereferon alpha. In the last 5 years, response to therapy has been considerably ameliorated thanks to the discovery of new drugs such as oxaliplatin and CPT-11. These agents, in combination with 5-fluorouracil, according to various schedules of treatment, have reached a significant improvement of palliation, response rate and survival. Immunotherapy is an uprising modality of treatment for human cancer including colorectal carcinoma. Its rationale is based on the knowledge that tumour cells are genetically unstable and produce molecular structures which allow their recognition and destruction by the immune-surveillance system. Therefore, humoral as well as cellular compartments of the immune system can be utilized according to a "passive" strategy (e.g. monoclonal antibody administration and adoptive immunotherapy) or an "active" approach, by using different modalities of vaccine therapy. In this context, monoclonal antibodies (mAbs) and cancer vaccines are being tested for the treatment of advanced colorectal cancer. Due to their genetic instability and extraordinary adaptative potential, tumour cells may acquire resistance to the immune effectors and mAbs exactly as they do for cytotoxic drugs. To improve the results of both immunological and chemical modality of cancer treatment, an increasing number of authors is starting to combine chemo and immunotherapy in the attempt to circumvent the limitations of both strategies. This report tries to review the possible rationale of the chemo-immunotherapy combination, illustrating preliminary results of preclinical and clinical studies.

Affinity of Iresine herbstii and Brugmansia arborea extracts on different cerebral receptors.

Iresine herbstii Hook. (Amaranthaceae) and Brugmansia arborea (L.) Lagerheim (Solanaceae) are used in the northern Peruvian Andes for magic-therapeutical purposes. The traditional healers use Iresine herbstii with the ritual aim to expel bad spirits from the body. Furthermore, Iresine herbstii was used in association with other plants, such as Trichocereus pachanoi Britt. et Rose, for divination, to diagnose diseases, and to take possession of another identity. Also, species of Brugmansia have been reported to be used during ritual practices for magical and curative purposes. Given the above evidence, the aim of the present study is to evaluate if the central effects of Iresine herbstii and Brugmansia arborea could be associated with interaction with SNC receptors. Two Iresine herbstii extracts (methanolic and aqueous) and one Brugmansia arborea aqueous extract were tested for in vitro affinity on 5-HT(1A), 5-HT(2A), 5-HT(2C), D1, D2, alpha(1), and alpha(2) receptors by radioligand binding assays. The biological materials for binding assay (cerebral cortex) were taken from male Sprague-Dawley rats. The extracts affinity for receptors is definite as inhibition percentage of radioligand/receptor binding and measured as the radioactivity of remaining complex radioligand/receptor. The data obtained for Iresine extracts have shown a low affinity for the 5-HT(1A) receptor and no affinity for 5-HT(2A) receptor. Otherwise the methanolic extract showed affinity for 5-HT(2C) receptor (IC(50): 34.78 microg/ml) and for D1 receptor (IC(50): 19.63 microg/ml), instead the Iresine aqueous extract displayed a lower affinity for D1 (48.3% at the maximum concentration tested) and a higher value of affinity for D2 receptors (IC(50): 32.08 microg/ml). The Brugmansia aqueous extract displayed affinity for D1 receptors (IC(50): 17.68 microg/ml), D2 receptors (IC(50): 15.95 microg/ml) and weak affinity for the serotoninergic receptors. None of the three extracts showed relevant affinity to the alpha(1), and alpha(2) receptors. The results of our experiments indicate that Iresine herbstii methanolic extract was able to interact with the central 5-HT(2C) and D1 receptors and Iresine herbstii aqueous extract showed affinity for D2 receptors, thus confirming their ritual use. Instead Brugmansia arborea was able to interact only with the central dopamine receptors tested. Parallel studies are currently in progress for evaluating the extracts affinity and active components towards these and other receptor types (GABAergic).

5-fluorouracil-based chemotherapy enhances the antitumor activity of a thymidylate synthase-directed polyepitopic peptide vaccine.

BACKGROUND: Thymidylate synthase (TS), a key enzyme in DNA synthesis, is often overexpressed in cancer cells. Some chemotherapeutic agents, such as 5-fluorouracil (5-FU), act by inhibiting TS expression. We evaluated whether a novel 28-amino acid multiepitope peptide, TS/PP, that contains the sequences of three TS-derived epitopes with binding motifs for HLA-A(*)02.01 could induce a TS-directed cytotoxic T-lymphocyte (CTL) response with antitumor activity. METHODS: TS/PP peptide immunologic activity in CTL lines derived from human leukocyte antigen (HLA)-A(*)02.01+ peripheral blood mononuclear cells (PBMCs) was tested in the presence of interleukin-2 and autologous TS/PP peptide-loaded dendritic cells. Immunologic and antitumor activities of TS/PP and its toxicity were also evaluated in vivo in HLA-A(*)02.01 transgenic (HHD) mice that were vaccinated with TS/PP, control, or TS-peptide cocktail and treated with or without 5-FU chemotherapy. The mice were also inoculated subcutaneously with TS-expressing EL-4/HHD lymphoma cells to assess immune response against these tumor cells. RESULTS: TS/PP-specific CTL lines showed a TS-multiepitopic specificity and were able to kill TS+/HLA-A(*)02.01+ breast and colon carcinoma cells. The killing ability against target cells previously exposed to sublethal doses of 5-FU was statistically significantly greater than against untreated target cells (43.5% versus 26.5% at 25/1 effector to target ratio [Difference {diff} = 17.0]; 95% confidence interval [CI] = 12.6 to 20.4) for MDA-MB-231 breast carcinoma cells and 73.5 versus 48.5 (diff = 25.0; 95% CI = 16.2 to 33.8) for the SW-1463 colon carcinoma cells. HHD mice vaccinated with TS/PP manifested a TS-peptide-specific CTL response with no sign of autoimmunity or toxicity. Furthermore, treatment of these mice with 5-FU delayed or prevented the occurrence of tumors formed by inoculation with autologous (TS+)EL-4/HHD lymphoma cells. CONCLUSIONS: The multiepitopic TS/PP vaccine induces a tumor-specific immune response in mice and is especially potent when used in combination with 5-FU-based chemotherapy.