Biomedical subjects

Li Zhu

Publications and source records attributed to Li Zhu.

At least 55 records · Page 3Linked to original sources

PubMed2006

Rate constants and kinetic isotope effects for unimolecular 1,2-HX or DX (X = F or Cl) elimination from chemically activated CF3CFClCH3-d0, -d1, -d2, and -d3.

Chemically activated CF(3)CFClCH(3), CF(3)CFClCD(3), CF(3)CFClCH(2)D, and CF(3)CFClCHD(2) molecules with 94 kcal mol(-1) of internal energy were formed by the combination of CF(3)CFCl radicals with CH(3), CD(3), CH(2)D, and CHD(2) radicals, which were generated from UV photolysis of CF(3)CFClI and CH(3)I, CD(3)I, CH(2)DI, or CHD(2)I. The total (HF + HCl) elimination rate constants for CF(3)CFClCH(3) and CF(3)CFClCD(3) were 5.3 x 10(6) and 1.7 x 10(6) s(-1) with product branching ratios of 8.7 +/- 0.6 in favor of HCl (or DCl). The intermolecular kinetic isotope effects were 3.22 and 3.18 for the HCl and HF channels, respectively. The product branching ratios were 10.3 +/- 1.9 and 11.8 +/- 1.8 (10.8 +/- 3.8 and 11.6 +/- 1.7) for HCl/HF and DCl/DF, respectively, from CF(3)CFClCH(2)D (CF(3)CFClCHD(2)). The intramolecular kinetic-isotope effects (without correction for reaction path degeneracy) for HCl/DCl and HF/DF elimination from CF(3)CFClCH(2)D (CF(3)CFClCHD(2)) were 2.78 +/- 0.16 and 2.98 +/- 0.12 (0.82 +/- 0.04 and 0.91 +/- 0.03), respectively. Density function theory at the B3PW91/6-311+G(2d,p) and B3PW91/6-31G(d',p') levels was investigated, and the latter was chosen to calculate frequencies and moments of inertia for the molecules and transition states. Rate constants, branching ratios and kinetic-isotope effects then were calculated using RRKM theory with torsional motions treated as hindered internal rotations. Threshold energies for HF and HCl elimination from CF(3)CFClCH(3) were assigned as 61.3 +/- 1.5 and 58.5 +/- 1.5 kcal mol(-1), respectively. The threshold energy for Cl-F interchange was estimated as 67 kcal mol(-1). The difference between the transition states for HCl and HF elimination is discussed.

Journal Article↗

PubMed2006

Satisfaction with mental health care among people with multiple sclerosis in urban and rural areas.

OBJECTIVES: This study explored urban and rural differences in mental health needs and treatments among people with multiple sclerosis, as well as their satisfaction with access to and quality of mental health care. METHODS: Data were collected in a nationwide survey of 1,518 people with multiple sclerosis. RESULTS: More than 40 percent of people with multiple sclerosis in each urban or rural area had received a diagnosis of depression, and more than 90 percent of them received mental health services, regardless of location of residence. However, rural residents were significantly less likely than their urban counterparts to receive the recommended combined medication and psychotherapy for treatment of depression. CONCLUSIONS: Current mental health care systems, even in rural areas, are capable of reaching out to patients with neuromedical illnesses, such as multiple sclerosis. Patients perceive some limitations in quality and accessibility, and recommended treatment differs between urban and rural areas.

Adult↗

PubMed2006

[Immunoregulation and short-term therapeutic effects of super-selective intra-arterial chemotherapy combined with traditional Chinese drugs on gastric cancer patients].

OBJECTIVE: To investigate the immunoregulation and short-term therapeutic effects of super-selective intra-arterial chemotherapy combined with Fuzheng Kang'ai Granules, a compound Chinese herbal medicine, on patients with late gastric cancer. METHODS: Forty patients with late gastric antrum cancer were randomly divided into study group and control group. Patients in the study group were orally administered Fuzheng Kang'ai Granules 48 hours after the first super-selective left gastric artery chemotherapy with high-dose drugs (EAP regime: VP(16) 100 mg/m(2) + epirubicin 60 mg/m(2) + carboplatin 200 mg/m(2)), while patients in the control group were only administered the same local artery chemotherapy as in the study group. RESULTS: The short-term therapeutic efficacy in the study group and control group were 82.5% and 57.5% respectively (P<0.01). The occurrence rates of side effects in the study group were significantly lower than those in the control group (P<0.01). The Karnofsky score of life quality of the study group was obviously higher than that of the control group after treatment (P<0.05). The half survival time and one year survival rate in the study group and control group were (24.9 +/- 1.36) month, 70% (28/40) and (13.7 +/- 0.72) month, 35% (14/40) respectively. They were significantly improved in the study group compared with the control group (P<0.01). The levels of cytokines interleukin 2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) after treatment in the study group were significantly higher than those before treatment (P<0.05 or P<0.01), as well as than those after treatment in the control group (P<0.01). On the other hand, the level of immune inhibitory factor soluble interleukin-2 receptor (sIL-2R) after treatment in the study group was lower than that before treatment, as well as than that after treatment in the control group (P<0.01). CONCLUSIONS: The super-selective intra-arterial chemotherapy combined with Fuzheng Kang'ai Granules has good short-term therapeutic efficiency and few side effects for patients with late gastric antrum cancer. It can significantly improve the life quality, extend the survival period, and improve the survival rate in patients with late gastric antrum cancer, which may be due to the up-regulation of the immune regulating factors such as IL-2, TNF-alpha, IFN-gamma and down-regulation of the immune inhibitory factor sIL-2R.

Adult↗

PubMed2006

[A clinical analysis of intractable spontaneous epistaxis with 289 cases reviewed].

OBJECTIVE: To explore the clinical characteristics and the prevention strategy of intractable spontaneous epistaxis. METHOD: Two hundred and eighty-nine patients with intractable spontaneous epistaxis were retrospectively analyzed. RESULT: Intractable spontaneous epistaxis was characterized by the onset season, age, sex, and the associated disease. Nasal septums were the most common sites of bleeding. Recurrent epistaxis was mainly associated with the failure of locating the bleeding sites. CONCLUSION: Control of elevated blood pressure is essential for the prevention of intractable spontaneous epistaxis. Once epistaxis occurs, the importance of the first treatment for the haemostasis should be emphasized. For the uncontrollable epistaxis, multiple interventions are necessary.

Adolescent↗

PubMed2006

Possible predictive markers related to micro-metastasis in breast cancer patients.

Despite significant advances in micro-metastasis detection methods, little is known about the relationship between micro-metastasis and primary tumors. The purpose of this study was to assess the ability of expression of the breast cancer-related markers, HER-2/neu, COX-2, VEGF and PDGF-B, as a predictor for micro-metastasis. As destination sites for micro-metastasis, we examined the peripheral blood (BD), bone marrow (BM) and sentinel lymph node (SLN) from 53 breast cancer patients. Protein and gene expression of the markers at the primary site were determined by immunohistochemistry (IHC) and quantitative RT-PCR. BD and BM samples were processed using magnetic-activated cell separation and immunocytochemistry. SLNs were examined by hematoxylin and eosin (H&E) staining and IHC. The percentages of patients with micro-metastasis were 24.5% in BD, 56.6% in BM, 26.4% in SLN by H&E and 41.5% in SLN by IHC. COX-2 gene amplification was significantly associated with SLN micro-metastasis by H&E (P=0.03). Overexpression of HER-2/neu predicts the presence of SLN micro-metastasis as detected by H&E (P=0.005) and COX-2 overexpression predicts the presence of micro-metastasis in BM (P=0.005) and SLN by H&E (P<0.001) and IHC (P<0.001). Similarly, PDGF-B overexpression predicts micro-metastasis in BD (P=0.002), BM (P=0.003) and SLN by H&E (P=0.017), whereas VEGF overexpression predicts only the presence of SLN micro-metastasis by IHC (P=0.001). Our results indicate the possible value of using these markers to predict the risk of micro-metastasis in breast cancer.

Biomarkers, Tumor↗

PubMed2006

[Effectiveness of improved intracavity microwave thermotherapy for nasopharyngeal carcinoma].

This study sought to evaluate the safety and effectiveness of intracavity microwave thermotherapy for nasopharyngeal carcinoma (NPC). The temperature images of the heating range were attained immediately after heating by LCP. The aim temperature (equal or over 40 degrees C) was achieved and then uniform thermal distribution in these areas was seen. Either phantoms or animal tests suggest that the temperature of all detected points are ranged from top to low: para-radiator, ipsilateral, parietal and contralateral wall of the simulated nasopharygeal cavity. Intracavity microwave thermotherapy is effective and safe for NPC by either phantoms or animal tests.

Animals↗

PubMed2006

[Stress proteins of Bifidobacterium longum NCC2705].

Stress proteins of Bifidobacterium longum strain NCC2705 were identified and characterized during stationary phase. According to the proteomic map of L. lactics IL1403 and theoretical Mr/pl of stress proteins in B. longum NCC2705 genome annotation, spots of stress proteins in gels were localized, and proteins were identified by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and/or ESI-MS/MS mass spectrometry. For protein identification by peptide mass fingerprinting, peptide masses were searched against database of B. longum NCC2705 by Mascot licensed in-house. 44 spots representing 8 protein entries have been identified, these proteins were hydrophilic proteins and predicted acid proteins. Spot and protein analysis revealed that post-translational modifications might be common in these proteins. Except for DnaJ, the stress proteins were encoded by genes with CAI value above 0.5, and represented a large proportion of the most abundant proteins. Moreover, the results of scavenging effects on free radicals in vitro showed that B. longum NCC2705 can inhibit fatty acid oxidation and scavenge DPPH, but they scavenge weakly active oxygen free radicals. We identified a key protein that can reverse oxidative damage to proteins and lipids: alkyl hydroperoxide reductase (ahpC, BL0615)synthesized under our experimental conditions.

Bacterial Proteins↗

PubMed2006

Urban/rural differences in the use of physician services by people with multiple sclerosis.

OBJECTIVE: to identify any urban/rural differences among people with multiple sclerosis (MS) in the utilization of physician services and MS-focused care, as well as differences in patient perceptions of access and quality. METHOD: data were collected by surveying 1,518 people with MS throughout the United States, equally divided among urban, urban-adjacent rural areas, and more remote rural areas. Standard SAS procedures were used to analyze the results. RESULTS: significantly larger proportions of people with MS in rural areas had a family or general practitioner as their primary physician while a significantly larger proportion of people with MS in urban areas had a neurologist as their primary physician. Rural residents traveled significantly greater distances to receive MS-focused care than their urban counterparts. People with MS living in more remote rural areas averaged less satisfaction with their access to a neurologist and to MS-focused care, and less satisfaction with the quality of care received, than people with MS in urban areas. CONCLUSION: limited availability of MS specialists in rural areas, and greater travel time and distance required to receive care from these providers, present future challenges to providing appropriate and high quality MS-focused care to people living with MS in rural areas.

Female↗

PubMed2005

Apoptosis mechanisms of human gastric cancer cell line MKN-45 infected with human mutant p27.

AIM: To explore the inducing effect of human mutant p27 gene on the apoptosis of the human gastric cancer cell line MKN-45 and its associated mechanisms. METHODS: The recombinant adenovirus Ad-p27mt was constructed to infect the human gastric cancer cell line MKN-45. Using flow cytometry, TUNEL assay and DNA fragment analysis, we measured the apoptotic effect of Ad-p27mt on the human gastric cancer cells. RESULTS: Ad-p27mt was successfully constructed and the infection efficiency reached 100%. After 18 h of infection, we observed an apoptotic hypodiploid peak on the flow cytometer before G1-S and apoptotic characteristic bands in the DNA electrophoresis. The apoptotic rate detected by TUNEL method was significantly higher in the Ad-p27mt group (89.4+/-3.12%) compared to the control group (3.12+/-0.13%, P < 0.01). CONCLUSION: Human mutant p27 can induce apoptosis of the human gastric cancer cells in vitro.

Animals↗

PubMed2005

Increased divalent metal transporter 1 expression might be associated with the neurotoxicity of L-DOPA.

Based on the available data, we speculated that changes in brain iron metabolism induced by L-DOPA might be associated with the neurotoxicity of L-DOPA. To investigate this possibility, the effects of L-DOPA on the expression of iron influx proteins [transferrin receptor (TfR) and divalent metal transporter 1 (DMT1)], iron efflux protein (ferroportin 1), and iron uptake in C6 glioma cells were determined in this study using Northern blot and Western blot analysis and the calcein method. The findings showed that treatment of C6 cells with different concentrations of L-DOPA (0-100 microM) did not affect the expression of mRNA and protein of TfR and DMT1 with iron-responsive element (+IRE) and protein of ferroportin 1. However, a significant increase in the expression of DMT1(-IRE) mRNA and protein was found in cells treated, respectively, with 10 and 30 microM L-DOPA (mRNA) and 1, 5, 10 and 30 microM L-DOPA (protein). The increase in DMT(-IRE) protein induced by L-DOPA treatment was in parallel with the increase in DMT(-IRE) mRNA. The levels of DMT1(-IRE) mRNA and protein peaked in the cells treated with 10 microM L-DOPA and then decreased progressively with increasing concentrations of L-DOPA. Further study demonstrated that treatment of the cells with 10 microM L-DOPA induced a significant increase in ferrous uptake by C6 glioma cells. The findings suggested that the increased DMT1(-IRE) expression might be partly associated with the neurotoxicity of L-DOPA. Clinical relevance of the findings needs to be investigated further.

Animals↗

PubMed2005

Amelioration of oxidant stress by the defensin lysozyme.

Reactive oxidant species (ROS), products of normal metabolism, cause oxidant injury if they accumulate in pathological amounts. Lysozyme (LZ) contains an 18-amino acid domain that binds agents such as advanced glycation end products (AGE) that generate ROS. We examined whether endogenous LZ affected physiological, or baseline, antioxidant balance and provided protection against both acute and chronic oxidant injury, using paraquat and H2O2 as agents of acute injury and AGE for chronic injury. Hen egg LZ-Tg mice had threefold higher serum LZ levels and decreased baseline AGE levels in serum and liver. These findings were linked to an enhanced baseline systemic GSH-to-GSSG ratio. Baseline levels of stress response genes p66(Shc) and c-Jun were also lower in liver tissue of LZ-Tg mice. Survival from severe oxidant injury induced by paraquat was twofold greater in LZ-Tg mice. In addition, LZ-Tg mice were resistant to chronic exogenous oxidant stress (OS) induced by AGE administration. Preincubation of hepatocytes (Hep G2) with LZ suppressed redox balance at baseline, as well as OS after added paraquat, AGE, or H2O2. LZ also ameliorated paraquat-enhanced cell apoptosis in a dose-dependent manner and suppressed AGE-induced p66(Shc) expression and c-Jun phosphorylation in Hep G2 cells. Thus LZ provides protection against acute and chronic oxidant injury by mechanisms involving suppression of ROS generation and of OS response genes.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Pharmacological and rAAV gene therapy rescue of visual functions in a blind mouse model of Leber congenital amaurosis.

BACKGROUND: Leber congenital amaurosis (LCA), a heterogeneous early-onset retinal dystrophy, accounts for approximately 15% of inherited congenital blindness. One cause of LCA is loss of the enzyme lecithin:retinol acyl transferase (LRAT), which is required for regeneration of the visual photopigment in the retina. METHODS AND FINDINGS: An animal model of LCA, the Lrat-/- mouse, recapitulates clinical features of the human disease. Here, we report that two interventions--intraocular gene therapy and oral pharmacologic treatment with novel retinoid compounds--each restore retinal function to Lrat-/- mice. Gene therapy using intraocular injection of recombinant adeno-associated virus carrying the Lrat gene successfully restored electroretinographic responses to approximately 50% of wild-type levels (p < 0.05 versus wild-type and knockout controls), and pupillary light responses (PLRs) of Lrat-/- mice increased approximately 2.5 log units (p < 0.05). Pharmacological intervention with orally administered pro-drugs 9-cis-retinyl acetate and 9-cis-retinyl succinate (which chemically bypass the LRAT-catalyzed step in chromophore regeneration) also caused long-lasting restoration of retinal function in LRAT-deficient mice and increased ERG response from approximately 5% of wild-type levels in Lrat-/- mice to approximately 50% of wild-type levels in treated Lrat-/- mice (p < 0.05 versus wild-type and knockout controls). The interventions produced markedly increased levels of visual pigment from undetectable levels to 600 pmoles per eye in retinoid treated mice, and approximately 1,000-fold improvements in PLR and electroretinogram sensitivity. The techniques were complementary when combined. CONCLUSION: Intraocular gene therapy and pharmacologic bypass provide highly effective and complementary means for restoring retinal function in this animal model of human hereditary blindness. These complementary methods offer hope of developing treatment to restore vision in humans with certain forms of hereditary congenital blindness.

Acyltransferases↗

PubMed2005

Reduced cisplatin sensitivity of head and neck squamous cell carcinoma cell lines correlates with mutations affecting the COOH-terminal nuclear localization signal of p53.

PURPOSE: Head and neck squamous cell carcinomas (HNSCC) are the most frequent malignancies of the upper aerodigestive tract. Cisplatin resistance is a major problem in the treatment of a large number of HNSCC cancer patients. In this study, nine randomly selected HNSCC cell lines were investigated regarding expression, presence of mutations, nucleocytoplasmic distribution of p53, and sensitivity to cisplatin. EXPERIMENTAL DESIGN: Protein expression was evaluated by Western blot analysis. The whole open reading frame of p53 was determined by reverse transcription-PCR sequencing. Nucleocytoplasmic distribution was evaluated by confocal laser scanning microscopy. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay was used to test for cisplatin sensitivity. RESULTS: p53 mutations were found in all nine investigated HNSCC cell lines. Nuclear p53 signal was detected in six cell lines, whereas three cell lines exhibited total loss of nuclear p53 signal. Nuclear signal depended on the presence or absence of the COOH-terminal nuclear localization signal in p53. Cisplatin sensitivity was highly reduced in the group with loss of nuclear p53 signal compared with those with detectable nuclear signal. Transfection of wild-type and mutant p53 into a rat embryonic cell system showed highly reduced activity of the nuclear localization signal mutant p53 protein. CONCLUSION: Taken together, these data suggest that "loss of nuclear p53 signal" correlates with cisplatin resistance in HNSCC. If these results can be validated on a larger number of tumor samples, including fresh tumor tissues, it potentially could help in sparing a subgroup of HNSCC patients the side effects associated with unnecessary chemotherapy by identifying cisplatin nonresponders before chemotherapy induction.

Adult↗

PubMed2005

[Angiotensin-converting enzyme inhibitors potentiate subthreshold preconditioning through NO and mitoK(ATP) channel.].

The aim of the present study was to determine whether angiotensin-converting enzyme inhibitors (ACEI) could contribute to the protective effects of preconditioning, and to explore its underlying mechanism. The Langendorff model of isolated rat heart was used. Cardiac contractility and lactate dehydrogenase (LDH) in the coronary effluent were measured, and infarct area of hearts after 30 min of ischemia followed by 120 min of reperfusion was analyzed. We found that: (1) The subthreshold preconditioning (2 min of ischemia and 10 min of reperfusion), captopril (an ACEI with sulfhydryl groups) or perindoprilate (an ACEI without sulfhydryl groups) alone did not protect the hearts from being injured by 30 min of ischemia and 120 min of reperfusion. (2) However, the combination of captopril or perindoprilate with subthreshold preconditioning could decrease left ventricular end-diastolic pressure (LVEDP), increase left ventricular developed pressure (LVDP) and coronary flow compared with the subthreshold preconditioned group. The combination treatments also inhibited the release of LDH from ischemia/reperfusion hearts, and reduced the infarct area in ischemic heart after 2 h of reperfusion (P<0.05). (3) By using NOS inhibitor L-NAME (100 mumol/L) before combined administration of ACEI with subthreshold preconditioning, the protection effect triggered by the combination treatment was significantly reduced. Pretreatment of the hearts with mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel inhibitor 5-HD (100 mumol/L) also abolished the protection effect (P<0.05). (4) Subthreshold preconditioning, captopril or perindoprilate alone could enhance the NO content in coronary effluent (P<0.05), but the combination of captopril or perindoprilate with subthreshold preconditioning could further augment the NO content compared with the subthreshold preconditioned group (P<0.05). The results indicate that ACEIs with or without sulfhydryl groups may potentiate the subthreshold preconditioning to trigger cardiac protection effect against the ischemia/reperfusion injury. This protection effect in the heart is possibly mediated by the generation of NO and the activation of mitoK(ATP) channel.

English Abstract↗

PubMed2005

Prostaglandin E2 induces FOXP3 gene expression and T regulatory cell function in human CD4+ T cells.

Naturally occurring CD4+CD25+ regulatory T cells (T reg) are pivotal in suppressing immune responses and maintaining tolerance. The identification of molecules controlling T reg differentiation and function is important in understanding host immune responses in malignancy and autoimmunity. In this study we show that PGE2 enhances the in vitro inhibitory function of human purified CD4+CD25+ T reg cells. Moreover, PGE2 induces a regulatory phenotype in CD4+CD25- T cells. PGE2-treated T cell-mediated inhibition of anti-CD3-stimulated lymphocyte proliferation did not require cell contact. Phenotypic analysis revealed that PGE2 diminished CD25 expression in both CD4+CD25dim T cells and CD4+CD25bright T reg cells. PGE2 exposure induced the T reg cell-specific transcription factor forkhead/winged helix transcription factor gene (FOXP3) in CD4+CD25- T cells and significantly up-regulated its expression in CD4+CD25+ T reg cells. Similarly, 24-h incubation with supernatants from cyclooxygenase-2-overexpressing lung cancer cells that secrete high levels of PGE2 significantly induced FOXP3 in CD4+CD25- T cells. Finally, PGE2 up-regulated FOXP3 at both mRNA and protein levels and enhanced FOXP3 promoter activity. This is the first report indicating that PGE2 can modulate FOXP3 expression and T reg function in human lymphocytes.

Adjuvants, Immunologic↗

PubMed2005

IL-20, an anti-angiogenic cytokine that inhibits COX-2 expression.

COX-2 overexpression and subsequent PGE(2) production are frequently associated with non-small cell lung cancer and are implicated in tumor-mediated angiogenesis. Here, we report for the first time that IL-20 downregulates COX-2 and PGE(2) in human bronchial epithelial and endothelial cells. Flow cytometry analysis suggests that IL-20-dependent inhibition of COX-2/PGE(2) occurs through the IL-22R1/IL-20R2 dimers. In addition, we report that IL-20 exerts anti-angiogenic effects, inhibiting experimental angiogenesis. IL-20-mediated inhibition of PMA-induced angiogenesis occurs through the COX-2 regulatory pathway. Altogether our findings revealed that IL-20 is a negative modulator of COX-2/PGE(2) and inhibits angiogenesis.

Angiogenesis Inhibitors↗

PubMed2005

Cyclooxygenase-2 expression is induced in rat brain after kainate-induced seizures and promotes neuronal death in CA3 hippocampus.

Cyclooxygenase-2 (COX-2) is the predominant isoform of cyclooxygenase in brain. COX-2 activity produces oxidative stress and results in the production of prostaglandins that have many injurious effects. COX-2 transcription is induced by synaptic activity; therefore, COX-2 activity could contribute to epileptic neuronal injury. To address this hypothesis, COX-2 protein expression and PGE2 production were determined after kainate-induced limbic seizures in rats. The effects of a specific COX-2 inhibitor, SC58125, on neuronal survival and PGE2 concentration in the hippocampus were also determined. COX-2 protein expression was increased in CA3, dentate gyrus, and cortex at 18-24 h after seizures. Hippocampal PGE2 levels were increased at 24 h following seizures, and treatment with the selective COX-2 inhibitor SC58125, 3 mg/kg p.o., attenuated the increase in PGE2 concentration. The survival of CA3 neurons at 7 days after seizures was increased in rats treated with SC58125 compared to vehicle controls. There was no effect of drug treatment on body or brain temperature, nor on the duration or rate of Type IV EEG activity. These results suggest that COX-2 activity can contribute to epileptic neuronal injury and that selective COX-2 inhibitors are neuroprotective.

Animals↗

PubMed2005

Cyclooxygenase 2 inhibition promotes IFN-gamma-dependent enhancement of antitumor responses.

In previous studies, we demonstrated an immune suppressive network in non-small cell lung cancer that is due to overexpression of tumor cyclooxygenase 2 (COX-2). In this study, we assessed the vaccination response to tumor challenge following either pharmacological or genetic inhibition of COX-2 in a murine lung cancer model. Treatment of naive mice with the COX-2 inhibitor, SC-58236, skewed splenocytes toward a type 1 cytokine response, inducing IFN-gamma, IL-12, and IFN-gamma-inducible protein 10, whereas the type 2 cytokines IL-4, IL-5, and IL-10 remained unaltered. Fifty percent of mice receiving SC-58236 and an irradiated tumor cell vaccine completely rejected tumors upon challenge. Those mice that did form tumors following challenge demonstrated a reduced tumor growth. In contrast, all mice either vaccinated with irradiated tumor cells alone or receiving SC-58236 alone showed progressive tumor growth. Studies performed in CD4 and CD8 knockout mice revealed a requirement for the CD4 T lymphocyte subset for the complete rejection of tumors. To determine the role of host COX-2 expression on the vaccination responses, studies were performed in COX-2 gene knockout mice. Compared with control littermates, COX-2(-/-) mice showed a significant tumor growth reduction, whereas heterozygous COX-2(-/+) mice had an intermediate tumor growth reduction following vaccination. In vivo depletion of IFN-gamma abrogated the COX-2 inhibitor-mediated enhancement of the vaccination effect. These findings provide a strong rationale for additional evaluation of the capacity of COX-2 inhibitors to enhance vaccination responses against cancer.

Adjuvants, Immunologic↗