Dosimetric evaluation of magnetic resonance imaging-guided adaptive radiation therapy in pancreatic cancer by extent of re-contouring of organs-at-risk

PURPOSE

The safety of online contouring and planning for adaptive radiotherapy is unknown. This study aimed to evaluate the dosimetric difference of the organ-at-risk (OAR) according to the extent of contouring in stereotactic magnetic resonance image-guided adaptive RT (SMART) for pancreatic cancer.

MATERIALS AND METHODS

We reviewed the treatment plan data used for SMART in patients with pancreatic cancer. For the online contouring and planning, OARs within 2 cm from the planning target volume (PTV) in the craniocaudal direction were re-controlled daily at the attending physician's discretion. The entire OARs were re-contoured retrospectively for data analysis. We termed the two contouring methods the Rough OAR and the Full OAR, respectively. The proportion of dose constraint violation and other dosimetric parameters was analyzed.

RESULTS

Nineteen patients with 94 fractions of SMART were included in the analysis. The dose constraint was violated in 10.6% and 43.6% of the fractions in Rough OAR and Full OAR methods, respectively (p = 0.075). Patients with a large tumor, a short distance from gross tumor volume (GTV) to OAR, and a tumor in the body or tail were associated with more occult dose constraint violations-large tumor (p = 0.027), short distance from GTV to OAR (p = 0.061), tumor in body or tail (p = 0.054). No dose constraint violation occurred outside 2 cm from the PTV.

CONCLUSION

More occult dose constraint violations can be found by the Full OAR method in patients with pancreatic cancer with some clinical factors in the online re-planning for SMART. Re-contouring all the OARs would be helpful to detect occult dose constraint violations in SMART planning. Since the dosimetric profile of SMART cannot be represented by a single fraction, patient selection for the Full OAR method should be weighted between the clinical usefulness and the time and workforce required.

Increased risk of cardiovascular diseases in patients with chronic rhinosinusitis: a longitudinal follow-up study using a national health screening cohort

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases and is characterized by sinonasal inflammation that lasts longer than 12 weeks. Whether the effect of chronic inflammation caused by CRS on cardiovascular diseases (CVDs) is similar to its effect on other inflammatory disorders has not been thoroughly evaluated. We aimed to demonstrate whether CRS patients have a higher prevalence of CVDs, including stroke and ischemic heart disease (IHD).

METHODOLOGY

We compared the prevalence of various comorbidities between CRS and control participants through a case-control cohort study from 2002 to 2015 that included 514,866 participants. CRS (n=6,552) and control (n=26,208) participants who were over 40 years old were selected by matching age, sex, income, and area of residence at a 1:4 ratio.

RESULTS

A stratified Cox proportional hazards model was utilized to assess the hazard ratio (HR) of CRS for stroke and IHD. The HRs for stroke and IHD were significantly increased in CRS patients compared to controls after adjusting for obesity, alcohol consumption, smoking, systolic and diastolic blood pressure, fasting blood glucose, total cholesterol, hemoglobin, and Charlson Comorbidity Index (CCI) scores. The HR of stroke was significantly higher in the absence of nasal polyps than in the presence of nasal polyps. The HR of IHD was significantly increased in the CRS group regardless of the presence of nasal polyps.

CONCLUSIONS

This study showed that CRS participants had a significantly higher prevalence of stroke and IHD.

Does serum vitamin D level affect the association between cardiovascular health and cognition? Results of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) study

BACKGROUND AND PURPOSE

Few studies have assessed the role of vitamin D in the association between cardiovascular risk factors and cognitive function. Here, the aim was to investigate the association between cardiovascular health (CVH) and cognitive function according to vitamin D level in a middle-aged Korean population.

METHODS

This cross-sectional study included 840 men and 1811 women (mean age 57.2 years) from the Cardiovascular and Metabolic Diseases Etiology Research Center study baseline enrolment (2013-2018). Life's Simple 7 tools from the American Heart Association were used to assess CVH. Cognitive function was evaluated using the Mini-Mental State Estimation for Dementia Screening (MMSE-DS), and the serum 25-hydroxyvitamin D level was measured.

RESULTS

In the adjusted generalized linear regression models, no significant association between a high Life's Simple 7 score (4-7 metric at optimal level) and MMSE-DS score (β = 0.01, P = 0.93) was found. Amongst men with a high vitamin D level, the high Life's Simple 7 score group showed a significantly higher MMSE-DS score (β = 0.48, P = 0.03). However, amongst men in the low vitamin D group, the association was opposite with no statistical significance (β = -0.23, P = 0.08). In women, the results were similar, but both strata according to vitamin D level showed no statistical significance.

CONCLUSIONS

Our findings suggest that vitamin D is an effect modifier in the association between CVH and cognition, especially in men.

Mental health states and influencing factors of risky and problem drinking in South Korean female adolescents

OBJECTIVES

Alcohol is one of the most used and abused psychoactive substances by adolescents. We investigated influencing factors of risky and problem drinking in Korean female adolescents.

STUDY DESIGN

The study design used is a cross-sectional modeling.

METHODS

We used data from the 13th Korean Youth Risk Behavior Web-based Survey (KYRBS) conducted in 2017. KYRBS data were obtained from a stratified, multistage, clustered sample. Risky drinking was binge drinking and problem drinking was drinking with several conflicts association with alcohol consumption.

RESULTS

Among 62,276 participants, the rates of current, risky, and problem drinking among all participants were 16.1%, 8.3%, and 6.1%, respectively. Although all of these rates were higher in males, risky and problem drinking rates among current female drinkers were higher than those of males (55.4 vs 48.5%, 38.9 vs 37.2%, respectively). Problem drinking was most strongly associated with risky drinking (adjusted odds ratio: 17.53 [95% confidence interval: 14.63-21.00]), similarly, risky drinking was most strongly associated with problem drinking in female current drinkers (17.76 [14.84-21.27]). Current smoking was the second strongest risk factor for risky and problem drinking in females (5.22 [3.92-6.95] and 2.93 [2.21-3.89], respectively).

CONCLUSION

Many female adolescents in Korea drink alcohol in an unhealthy manner. The female risky and problem drinking rates among current drinkers were higher than those of males. Risky drinking and problem drinking was most significant influencing factor among females, reciprocally. Public education on abstinence in female adolescents is warranted.

The Role of MRI in Diagnosing Neurovascular Compression of the Cochlear Nerve Resulting in Typewriter Tinnitus

BACKGROUND AND PURPOSE

Typewriter tinnitus, a symptom characterized by paroxysmal attacks of staccato sounds, has been thought to be caused by neurovascular compression of the cochlear nerve, but the correlation between radiologic evidence of neurovascular compression of the cochlear nerve and symptom presentation has not been thoroughly investigated. The purpose of this study was to examine whether radiologic evidence of neurovascular compression of the cochlear nerve is pathognomonic in typewriter tinnitus.

MATERIALS AND METHODS

Fifteen carbamazepine-responding patients with typewriter tinnitus and 8 control subjects were evaluated with a 3D T2-weighted volume isotropic turbo spin-echo acquisition sequence. Groups 1 (16 symptomatic sides), 2 (14 asymptomatic sides), and 3 (16 control sides) were compared with regard to the anatomic relation between the vascular loop and the internal auditory canal and the presence of neurovascular compression of the cochlear nerve with/without angulation/indentation.

RESULTS

The anatomic location of the vascular loop was not significantly different among the 3 groups (all, P > .05). Meanwhile, neurovascular compression of the cochlear nerve on MR imaging was significantly higher in group 1 than in group 3 (P = .032). However, considerable false-positive (no symptoms with neurovascular compression of the cochlear nerve on MR imaging) and false-negative (typewriter tinnitus without demonstrable neurovascular compression of the cochlear nerve) findings were also observed.

CONCLUSIONS

Neurovascular compression of the cochlear nerve was more frequently detected on the symptomatic side of patients with typewriter tinnitus compared with the asymptomatic side of these patients or on both sides of control subjects on MR imaging. However, considering false-positive and false-negative findings, meticulous history-taking and the response to the initial carbamazepine trial should be regarded as more reliable diagnostic clues than radiologic evidence of neurovascular compression of the cochlear nerve.

Thermal neutron response of a boron-coated GEM detector via GEANT4 Monte Carlo code

In this work, we report the design configuration and the performance of the hybrid Gas Electron Multiplier (GEM) detector. In order to make the detector sensitive to thermal neutrons, the forward electrode of the GEM has been coated with the enriched boron-10 material, which works as a neutron converter. A total of 5×5cm² configuration of GEM has been used for thermal neutron studies. The response of the detector has been estimated via using GEANT4 MC code with two different physics lists. Using the QGSP_BIC_HP physics list, the neutron detection efficiency was determined to be about 3%, while with QGSP_BERT_HP physics list the efficiency was around 2.5%, at the incident thermal neutron energies of 25meV. The higher response of the detector proves that GEM-coated with boron converter improves the efficiency for thermal neutrons detection.

Association between VEGF and eNOS gene polymorphisms and lumbar disc degeneration in a young Korean population

Disturbances in blood flow to intervertebral discs (IVD) play an important role in IVD degeneration. Vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) are extremely important angiogenic factors for vasodilation and neovascularization. We investigated the relationship between single nucleotide polymorphisms (SNPs) of the VEGF and eNOS genes and genetic susceptibility to lumbar IVD degeneration in a young adult Korean population. Two hundred and forty-one participants (aged 18 to 30 years), with or without low back pain, were selected for the study. Magnetic resonance imaging was made of the lumbar spine in all participants. The patient group (N = 102) had low back pain clinically and lumbar IVD degeneration radiographically. The control group (N = 139) included subjects with and without low back pain; all were negative radiographically for lumbar IVD degeneration. Using PCR-RFLP analysis, we analyzed VEGF (-2578C>A, -1154G>A, -634G>C, and 936C>T) and eNOS (-786T>C, 4a4b and 894G>T) SNPs. We made combined analyses of the genes and performed haplotype analyses. There were no significant differences in the genotype distribution of polymorphisms of VEGF and eNOS genes among patients and controls. However, the frequency of VEGF -2578CA +AA/-634CC combined genotypes was significantly higher in patients when compared with controls [odds ratio (OR) = 21.00; 95% confidence interval (CI) = 2.590- 170.240]. The frequencies of the -2578A/-1154A/-634C/936C (OR = 3.831; 95%CI = 1.068-13.742), -2578A/-1154A/-634C (OR = 3.356; 95%CI = 1.198-9.400), and -2578A/-634C/936C (OR = 10.820; 95%CI = 2.811-41.656) haplotypes were also significantly higher in patients than in controls. We conclude that the combined genotype VEGF -2578CA+AA/-634CC is a possible risk factor for IVD degeneration and the VEGF -2578A/-1154A/-634C/936C haplotype may increase the risk for development of IVD degeneration. Furthermore, the VEGF -634C allele appears to be associated with susceptibility to IVD degeneration.

Association of transforming growth factor-beta 1 gene polymorphism with genetic susceptibility to ossification of the posterior longitudinal ligament in Korean patients

Ossification of the posterior longitudinal ligaments (OPLL) has been considered to be associated with abnormalities of bone metabolism, and transforming growth factor-β1 (TGF-β1) has been demonstrated to affect the bone remodeling process. We investigated two SNPs of the TGF-β1 promoter (-509C>T; rs1800469) and exon 1 (869T>C; rs1982073) in 298 Koreans (98 patients with OPLL and 200 control subjects). The promoter SNP -509C>T was determined by PCR and RFLP, and the TaqMan probe assay was used to determine 869T>C polymorphism genotypes. The subjects were divided into OPLL continuous group (continuous type plus mixed type) and OPLL segmental group (segmental and localized type). We also separately analyzed this association according to gender difference. There was no significant difference in genotype distributions of -509C>T and 869T>C polymorphisms of the TGF-β1 gene between OPLL patients and controls. A combined analysis of TGF-β1 -509C>T and 869T>C polymorphisms showed no significant association with OPLL, and a subgroup analysis did not show any significant correlation between the SNP -509C>T or SNP 869T>C and OPLL subgroups. Stratification by gender demonstrated no significant effect. We conclude that promoter region (-509C>T) and exon 1 (869T>C) polymorphisms are not associated with OPLL in the Korean population.

Proteins involved in DNA damage response pathways and survival of stage I non-small-cell lung cancer patients

BACKGROUND

Biological complexity leads to significant variation in the survival of patients with stage I non-small-cell lung cancer (NSCLC). DNA damage response (DDR) pathways play a critical role in maintaining genomic stability and in the progression of NSCLC. Therefore, the development of a prognostic biomarker focusing on DDR pathways is an intriguing issue.

PATIENTS AND METHODS

Expression of several proteins (ATM, ATMpS1981, γH2AX, 53BP1, 53BP1pS25, Chk2, Chk2pT68, MDC1, MDC1pS964, BRCA1pS1423, and ERCC1) and overall survival were investigated in 889 pathological stage I NSCLC patients.

RESULTS

Low expression of BRCA1pS1423 or ERCC1 was significantly associated with worse survival in the whole cohort of patients. Analysis performed based on histology revealed that low expression of γH2AX, Chk2pT68, or ERCC1 was a poor prognostic factor in squamous cell carcinoma patients [adjusted hazard ratio (aHR), Cox P: 1.544, 0.012 for γH2AX; 1.624, 0.010 for Chk2pT68; 1.569, 0.011 for ERCC1]. The analysis of the interaction between two proteins showed that this effect was more pronounced in squamous cell carcinoma patients. However, these effects were not detected in adenocarcinoma patients.

CONCLUSIONS

The proteins involved in DDR pathways exhibited differential expression between squamous cell carcinoma and adenocarcinoma and were important determinants of survival in stage I squamous cell carcinoma patients.

Effect of mangrove black tea extract from Ceriops decandra (Griff.) on hematology and biochemical changes in dimethyl benz[a]anthracene-induced hamster buccal pouch carcinogenesis

Effect of the black tea extracted from a mangrove plant species, Ceriops decandra (Griff.) was studied on dimethyl benz[a]anthracene (DMBA)-induced changes in blood hematology and plasma non-enzymatic antioxidants in male hamsters. Hamsters were painted with 0.5% solution of DMBA in liquid paraffin on the right buccal pouch three times in a week up to 14 weeks. Each application treated with 0.4mg of DMBA. The mangrove black tea extract (MBTE) was administrated orally with 5mgkg(-1) twice a day and then with DMBA on alternate days. Results showed that the DMBA caused a significant (P<0.05) decline in the levels of reduced glutathione (GSH), vitamin-C, -E, red blood cells, hemoglobin, mean corpuscular volume and hematocrit; and increase in the levels of WBC, platelets, lymphocytes and neutrophils. The MBTE prevented the DMBA-induced adverse changes significantly in blood and biochemical parameters of the male hamsters. This work concluded that the black tea extracted from the coastal mangrove species C. decandra prevented the DMBA-induced buccal pouch carcinogenesis in hamsters.

Control of AIF-mediated cell death by antagonistic functions of CHIP ubiquitin E3 ligase and USP2 deubiquitinating enzyme

Apoptosis inducing factor (AIF) is a mitochondrial oxidoreductase that scavenges reactive oxygen species under normal conditions. Under certain stresses, such as exposure to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG), AIF is truncated and released from the mitochondria and translocated into the nucleus, where the truncated AIF (tAIF) induces caspase-independent cell death. However, it is unknown how cells decide to kill themselves or operate ways to survive when they encounter stresses that induce the release of tAIF. Here, we demonstrated that USP2 and CHIP contribute to the control of tAIF stability. USP2 deubiquitinated and stabilized tAIF, thus promoting AIF-mediated cell death. In contrast, CHIP ubiquitinated and destabilized tAIF, thus preventing the cell death. Consistently, CHIP-deficient cells showed an increased sensitivity to MNNG. On the other hand, knockdown of USP2 attenuated MNNG-induced cell death. Moreover, exposure to MNNG caused a dramatic decrease in CHIP level, but not that of USP2, concurrent with cell shrinkage and chromatin condensation. These findings indicate that CHIP and USP2 show antagonistic functions in the control of AIF-mediated cell death, and implicate the role of the enzymes as a switch for cells to live or die under stresses that cause tAIF release.

Comparative evaluations of cellulosic raw materials for second generation bioethanol production

AIMS

To evaluate sugar recoveries and fermentabilities of eight lignocellulosic raw materials following mild acid pretreatment and enzyme hydrolysis using a recombinant strain of Zymomonas mobilis.

METHODS AND RESULTS

Dilute acid pretreatment (2% H(2) SO(4) ) with 10% (w/v) substrate loading was performed at 134°C for 60 min followed by enzyme hydrolysis at 60°C. The results demonstrated that hydrolysis of herbaceous raw materials resulted in higher sugar recoveries (up to 60-75%) than the woody sources (<50%). Fermentation studies with recombinant Z. mobilis ZM4 (pZB5) demonstrated that final ethanol concentrations and yields were also higher for the herbaceous hydrolysates. Significant reduction in growth rates and specific rates of sugar uptake and ethanol production occurred for all hydrolysates, with the greatest reductions evident for woody hydrolysates. Further studies on optimization of enzyme hydrolysis established that higher sugar recoveries were achieved at 50°C compared to 60°C following acid pretreatment.

CONCLUSIONS

Of the various raw materials evaluated, the highest ethanol yields and productivities were achieved with wheat straw and sugarcane bagasse hydrolysates. Sorghum straw, sugarcane tops and Arundo donax hydrolysates were similar in their characteristics, while fermentation of woody hydrolysates (oil mallee, pine and eucalyptus) resulted in relatively low ethanol concentrations and productivities. The concentrations of a range of inhibitory compounds likely to have influence the fermentation kinetics were determined in the various hydrolysates.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study focuses on lignocellulosic materials available for second generation ethanol fermentations designed to use renewable agricultural/forestry biomass rather than food-based resources. From the results, it is evident that relatively good sugar and ethanol yields can be achieved from some herbaceous raw materials (e.g. sugarcane bagasse and sorghum straw), while much lower yields were obtained from woody biomass.

A high yield of fetal nucleated red blood cells isolated using optimal osmolality and a double-density gradient system

OBJECTIVES

To increase the yield of fetal nucleated red blood cells (NRBCs) from maternal blood using a discontinuous Percoll gradient and to determine the effects of osmolality on NRBC yield.

METHODS

Fetal NRBCs were isolated from combined umbilical cord blood and adult female blood, or from maternal blood using single or double Percoll gradients with different osmolalities. Magnetic activated cell sorting was used to enrich isolated NRBCs, and morphological differentiation was performed with Kleihauer-Betke stain. We also isolated fetal NRBCs from 25 10 mL samples of maternal blood and determined fetal sex by fluorescence in situ hybridization (FISH), using X-Y probes.

RESULTS

For single-density Percoll columns, the greatest number of NRBCs was isolated using 280 mOsm/kg H(2)O with 1.077 g/mL Percoll and 520 mOsm/kg H(2)O with 1.119 g/mL Percoll. Significantly more fetal NRBCs were isolated with double Percoll density gradients than with double-Histopaque gradients (p = 0.043). FISH analysis on NRBC in 25 cases correctly identified 15 male and 9 female euploid fetuses and one Trisomy 21 fetus.

CONCLUSION

The NRBC enrichment method we present requires less maternal blood and yields more NRBCs compared to previous methods.

Histone deacetylase inhibitor apicidin downregulates DNA methyltransferase 1 expression and induces repressive histone modifications via recruitment of corepressor complex to promoter region in human cervix cancer cells

Dysregulation of DNA methyltransferase (DNMT)1 expression is associated with cellular transformation, and inhibition of DNMT1 exerts antitumorigenic effects. Here, we report that DNMT1 abnormally expressed in HeLa cells is downregulated by a histone deacetylase (HDAC) inhibitor apicidin, which is correlated with induction of repressive histone modifications on the promoter site. Apicidin selectively represses the expression of DNMT1 among DNMTs in HeLa cells, independent of cell cycle arrest at G0/G1. Furthermore, apicidin causes a significant reduction in the recruitment of RNA polymerase II into the promoter. Chromatin immunoprecipitation analysis shows that even though apicidin causes global hyperacetylation of histone H3 and H4, localized deacetylation of histone H3 and H4 occurs at the E2F binding site, which is accompanied by the recruitment of pRB and the replacement of P/CAF with HDAC1 into the sites. In addition, K4-trimethylated H3 on nucleosomes associated with the transcriptional start site is depleted following apicidin treatment, whereas repressive markers, K9- and K27-trimethylation of H3 are enriched on the site. The downregulation of DNMT1 expression seems to require de novo protein synthesis, because the apicidin effect is antagonized by cycloheximide treatment. Moreover, knock down of DNMT1 with siRNA induces the apoptosis of HeLa cells, indicating that downregulation of DNMT1 might be a good strategy for therapeutics of human cervix cancer. Collectively, our findings will provide a mechanistic rationale for the use of HDAC inhibitors in cancer therapeutics.

Zymomonas mobilis for fuel ethanol and higher value products

High oil prices, increasing focus on renewable carbohydrate-based feedstocks for fuels and chemicals, and the recent publication of its genome sequence, have provided continuing stimulus for studies on Zymomonas mobilis. However, despite its apparent advantages of higher yields and faster specific rates when compared to yeasts, no commercial scale fermentations currently exist which use Z. mobilis for the manufacture of fuel ethanol. This may change with the recent announcement of a Dupont/Broin partnership to develop a process for conversion of lignocellulosic residues, such as corn stover, to fuel ethanol using recombinant strains of Z. mobilis. The research leading to the construction of these strains, and their fermentation characteristics, are described in the present review. The review also addresses opportunities offered by Z. mobilis for higher value products through its metabolic engineering and use of specific high activity enzymes.

Polychlorinated biphenyls activate caspase-3-like death protease in vitro but not in vivo

We prove here that serum albumin inhibits apoptosis induced by polychlorinated biphenyls (PCBs), confirming that serum albumin binds to PCB, and that the albumin-PCB complexes inhibit apoptosis in HL-60 cells. We found that PCB (50 microM) increased the activity of caspase-3-like protease when HL-60 cells, as well as splenocytes, were cultured in "serum-free medium." Benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk) inhibited apoptosis in cells cultured in the serum-free medium containing 50 microM PCB. To elucidate whether or not PCBs induce apoptosis in vivo, we examined apoptosis of splenocytes by administering PCB to ICR mice (100, 500, 1000 mg x kg(-1) x d(-1)) for 5 d and characterizing splenocytes. Interestingly, splenocytes treated with PCB did not show any changes characteristic of apoptosis. These results demonstrate that PCB activates the caspase-3-like death protease in vitro in serum-free medium, but does not induce apoptosis of splenocytes in vivo, suggesting that blood serum may mask the apoptosis induced by PCB.

Prodigiosin blocks T cell activation by inhibiting interleukin-2Ralpha expression and delays progression of autoimmune diabetes and collagen-induced arthritis

Prodigiosin (PDG) was previously reported to be a T cell-specific immunosuppressant. Here we describe the mechanism of action of PDG in T cells and the effect of PDG on autoimmune diseases. PDG selectively suppresses concanavalin A (Con A)-induced T cell proliferation, but has little effect on lipopolysaccharide-induced proliferation of B cells and nitric oxide production of macrophages. Although PDG does not block interleukin (IL)-2 production, it efficiently inhibits interleukin-2 receptor alpha-chain (IL-2Ralpha) expression, and this results in a disruption of the IL-2/IL-2R signaling pathway, on which a great part of the regulation of T cell activation depends. PDG blocks T cell differentiation into effector helper T cells secreting interferon-gamma and IL-4 as well as into effector cytotoxic T lymphocytes expressing perforin, which is at least in part resulting from inhibition of the IL-2/IL-2R signaling. PDG indirectly blocks signal transducer and activator of transcription activation by inhibiting cytokine signalings in Con A-activated T cells, although it does not inhibit the activation of nuclear factor-kappaB, nuclear factor of activated T cells, and activator protein-1. As direct evidence of immunosuppression in vivo, we show that PDG markedly reduced blood glucose levels and cellular infiltration into the pancreatic islets in nonobese diabetic mice, and that it also delays the onset of collagen-induced arthritis in DBA/1 mice. In conclusion, our results demonstrate that PDG has a unique mode of action, namely, that it blocks T cell activation by inhibiting primarily IL-2Ralpha expression in the IL-2/IL-2R signaling, and show that this compound represents a promising immunosuppressant candidate for the treatment of autoimmune diseases.

Suppression of IL-8 gene expression by radicicol is mediated through the inhibition of ERK1/2 and p38 signaling and negative regulation of NF-kappaB and AP-1

We show that radicicol, an anti-fungal agent, inhibits interleukin-8 (IL-8) production by the human monocyte line THP-1 in response to phorbol-12-myristate-13-acetate/lipopolysaccharide (PMA/LPS). IL-8 is a potent chemokine and needs for an optimal immune response--such as inflammation by activation of neutrophils. The decrease in PMA/LPS-induced IL-8 mRNA expression was demonstrated by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Since the promoter in IL-8 gene contains binding motifs for NF-KB, AP-1. and NF-IL6, which appear to be important in IL-8 induction, the effects of radicicol on the activation of these transcription factors were examined. Treatment of radicicol to THP-1 cells produced a strong inhibition of NF-KB and AP-1, while NF-IL6 was not significantly affected by radicicol. Western blot analysis showed that radicicol inhibited the phosphorylation and phosphotransferase activities of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38. PD98059 and SB203580, known as a specific inhibitor of MEKI and p38 kinase, respectively, inhibited IL-8 gene expression showing that both of the kinase pathways are involved in IL-8 regulation in human monocytes. Collectively, this series of experiments indicates that radicicol inhibits IL-8 gene expression by blocking ERK1/2 and p38 signaling.

Experimental evidences and signal transduction pathways involved in the activation of NF-kappa B/Rel by angelan in murine macrophages

In our previous studies, we showed that angelan, a polysaccharide purified from Angelica gigas Nakai, activated macrophages to induce the translocation of NF-kappa B/Rel into nucleus and DNA binding to its cognate site in the promoter of iNOS gene [Immunopharmacology 43 (1999) 1; Immunopharmacology 49 (2000) 275]. In the present study, we showed that angelan induces the transcriptional activation of NF-kappa B/Rel and investigated the intracellular signal transduction pathways involved in the angelan-induced NF-kappa B/Rel activation by murine macrophages. Treatment of RAW 264.7 cells with angelan resulted in significant activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38, while stress-activated protein kinase/c-Jun NH2 terminal kinase (SAPK/JNK) was not activated by angelan. The specific p38 inhibitor SB203580 abrogated the angelan-induced NF-kappa B/Rel activation, whereas the selective MAPK/extracellular signal-regulated kinase 1 (MEK-1) inhibitor PD98059 did not affect the NF-kappa B/Rel induction. Treatment of RAW 264.7 cells with both anti-CD14 Ab and anti-CR3 Ab significantly blocked angelan-induced NF-kappa B/Rel activation. In conclusion, we demonstrate that angelan induces NF-kappa B/Rel activation through the CD14 and CR3 membrane receptor and p38 kinase that is critically involved in the signal transduction leading to NF-kappa B/Rel activation in murine macrophages.

Transcription factor decoy for activator protein-1 (AP-1) inhibits high glucose- and angiotensin II-induced type 1 plasminogen activator inhibitor (PAI-1) gene expression in cultured human vascular smooth muscle cells

AIMS/HYPOTHESIS

Multiple factors, including hyperglycaemia and angiotensin II (Ang II), stimulate plasminogen activator inhibitor-1 (PAI-1) gene expression in human vascular smooth muscle cells. This study tested the hypothesis that hyperglycaemia and Ang II stimulate PAI-1 gene expression through activator protein-1 (AP-1) binding sites.

METHODS

We evaluated the role of AP-1 in PAI-1 gene expression in human vascular smooth muscle cells under high D-glucose and Ang II stimulation using a double-stranded cis-element AP-1 oligodeoxynucleotide (decoy ODN).

RESULTS

Activator protein 1 activity was stimulated by high glucose and Ang II treatment and the AP-1 decoy ODN, but not a mismatched decoy ODN, competed for AP-1 activity. The increase in PAI-1 expression by high glucose and Ang II was significantly attenuated by the AP-1 decoy ODN (p <0.05 or p < 0.01). The increase in PAI-1 expression by high glucose and Ang II action on AP-1 sites was also confirmed by promoter analysis of PAI-1. Activator protein 1 activation in response to either high glucose or co-stimulation with high glucose and Ang II was inhibited completely by calphostin C (a PKC inhibitor) and partially by genistein (a protein tyrosine kinase inhibitor).

CONCLUSION/INTERPRETATION

This study shows that high glucose and Ang II stimulate PAI-1 expression through AP-1 binding sites. Signal transduction after AP-1 activation by both high glucose and Ang II largely depends on PKC activation. These data indicate an important role for AP-1 in PAI-1 expression.

Molecular cloning and high-level expression of G2 protein of hantaan (HTN) virus 76-118 strain in the yeast Pichia pastoris KM71

Hantaan viral G2 envelope gene, which is known to be one of major antigens and induce neutralizing antibodies, was cloned into expression vector pHIL-S1 which consists of AOX1 promoter, PHO1 signal sequence, HIS4 gene and other components. The recombined plasmid was transformed into methylotropic yeast, Pichia pastoris of KM71 and recombinant strains harboring multi-copy of G2 gene were selected. Expression of the cloned G2 gene was confirmed with Western blot analysis using anti-sera of guinea pig immunized with the carboxyl terminal region of G2 protein expressed in Escherichia coli. The expression of G2 gene from the recombinant strain was tightly repressed by dextrose and effectively induced by methanol, an inducer of AOX1 promoter. The highest expression level was observed from 1 day after induction and maintained at the same level for up to 4 days.

Paclitaxel-induced immune suppression is associated with NF-kappaB activation via conventional PKC isotypes in lipopolysaccharide-stimulated 70Z/3 pre-B lymphocyte tumor cells

Paclitaxel, a potent antitumor agent, has been shown to be lipopolysaccharide (LPS) mimetic in mice, stimulating signaling pathways and gene expression indistinguishably from LPS. In the present study, we showed the intracellular signaling pathway of paclitaxel-induced nuclear factor-kappaB (NF-kappaB) activation and its suppressive effect on LPS-induced signaling in murine 70Z/3 pre-B cells. Stimulation of 70Z/3 cells with LPS for 30 min caused activation of NF-kappaB in the nuclei by detection of DNA-protein binding specific to NF-kappaB. Similarly, paclitaxel also produced a marked and dose-related NF-kappaB activation. However, pretreatment of cells with 10 microM paclitaxel for 18 h resulted in complete inhibition of LPS-mediated NF-kappaB activation. Interestingly, the activity of IkappaB kinase (IKK-beta), which plays an essential role in NF-kappaB activation through IkappaB phosphorylation, was largely enhanced in paclitaxel-treated cells, detected as IkappaBalpha phosphorylation. Because protein kinase C (PKC) is implicated in the activation of NF-kappaB via IKK-beta, the effect of paclitaxel on PKC activation was also measured. It was shown that NF-kappaB nuclear translocation and DNA binding in response to paclitaxel was completely blocked by the conventional PKC inhibitor, Gö 6976. Moreover, immunoblotting analysis with paclitaxel-treated cell extract demonstrated that the conventional PKC isotype PKC-alpha was found to be involved in the regulation of paclitaxel-induced NF-kappaB activation, as determined by electrophoretic mobility shift of PKC. Therefore, these data suggest that paclitaxel may activate IKK-beta via conventional PKC isotypes, resulting in NF-kappaB activation and, finally, desensitization of LPS-inducible signaling pathway in 70Z/3 pre-B cells.

Activation of mitogen-activated protein kinase pathways by angelan in murine macrophages

In our previous studies, we showed that angelan, a polysaccharide purified from Angelica gigas Nakai, specifically activated macrophages to induce cytokines including inducible nitric oxide synthase (iNOS) which has strong anti-tumor activities [Immunopharmacology, 1999; 43: 1.]. In the present study, we investigated the intracellular signal transduction pathways involved in the angelan-induced iNOS synthesis by murine macrophages. Protein tyrosine phosphorylation was induced within 5 min by angelan, and the blocking of protein tyrosine kinases (PTKs) inhibited down-stream pathways leading to iNOS production in response to angelan. Treament of RAW 264.7 cells with angelan resulted in significant activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and p38, while stress-activated protein kinase/c-Jun NH2 terminal kinase (SAPK/JNK) was not activated by angelan. The specific p38 inhibitor SB203580 abrogated the angelan-induced iNOS synthesis, whereas the selective mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1 (MEK-1) inhibitor PD98059 did not affect the iNOS induction. In conclusion, we demonstrate that PTK and p38 MAPK activation are required to transduce signals leading to iNOS expression in angelan-stimulated murine macrophages.

Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage

It has been known that green tea and its components possess significant chemopreventive effects against chemical carcinogens and photo-caused skin tumor formation. In this study, the protective effects of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on the ultraviolet (UV)-induced skin damage (photoaging) were studied in guinea pigs, hairless mice and human dermal fibroblast cultures. The lipid peroxidation was significantly reduced in the EGCG-treated group. The amount of lipid peroxides produced in the control and EGCG treated group were 838 +/- 144 and 286 +/- 57 nmol/mg at 18 h after UV irradiation, respectively. UVB-induced erythema was also significantly reduced in the EGCG treated group. The erythema relative index of the control and the EGCG treated group were 311 +/- 45 and 191 +/- 49 at 16 h after UV irradiation, respectively. EGCG treatment reduced UVA-induced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-induced increase of collagen secretion and collagenase mRNA level in fibroblast culture. The nuclear transcription factors NF-kappaB and AP-1 binding activities were also inhibited by EGCG treatment.

Differential activation of murine macrophages by angelan and LPS

In our previous studies, we showed that angelan, a polysaccharide purified from Angelica gigas Nakai, is a potent LPS-mimetic in murine macrophages [Jeon, Y.J., Han, S.B., Ahn, K.S., Kim, H.M., 1999. Activation of NF-kB/Rel in angelan-stimulated macrophages. Immunopharmacology 43, 1-9]. Angelan stimulates murine macrophage to produce cytokines including iNOS and activate NF-kappaB/Rel. In the present study, we investigated the role of CD14 and complement receptor type 3 (CR3) in mediating NO production and NF-kappaB/Rel activation induced by angelan and LPS. Three major differences between angelan and LPS were observed. First, angelan does not require serum proteins for NO response and NF-kappaB/Rel activation, while the activation by LPS requires serum proteins. Second, blocking of either CD14 or CR3 decreased angelan-induced NO response, while LPS-mediated NO production was inhibited by anti-CD14 mAb only. Third, angelan induced strong NF-kappaB/Rel and slight AP-1 DNA binding, whereas LPS potently activated both NF-kappaB/Rel and AP-1. Both angelan and LPS degraded IkappaB proteins and subsequently induced the mobilization of NF-kappaB/Rel proteins (p65, c-rel and p50) into nucleus. This suggests that macrophages display a common signaling machinery leading to the NF-kappaB/Rel activation in response to different stimulants. In conclusion, angelan and LPS use the membrane receptor CD14 and CR3 differentially for signaling NF-kappaB/Rel activation and NO production.

2-Amino-3-methylimidazo[4,5-f]quinoline inhibits nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells by blocking p38 kinase activation

We show that 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a heterocyclic amine, significantly inhibits nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages. The decrease in NO production was found to correlate well with a decrease in inducible NO synthase (iNOS) mRNA expression as demonstrated by Northern blot analysis. Treatment of RAW 264.7 cells with IQ selectively inhibited the activation of NF-kappaB/Rel, an important transcription factor of iNOS gene expression, while neither AP-1 nor Oct was affected by IQ. Since iNOS transcription has been shown recently to be under the control of the p38 kinase signaling cascade, we assessed the effect of IQ on p38 kinase activation. Treatment of RAW 264.7 with IQ inhibited LPS-stimulated p38 kinase phosphorylation in a dose-related manner. IQ also inhibited the p38 kinase activity. Collectively, this series of experiments indicates that IQ inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Based on our findings, the most likely mechanism that can account for this biological effect involves the negative regulation of NF-kappaB/Rel and p38 kinase pathway.

Radicicol suppresses expression of inducible nitric-oxide synthase by blocking p38 kinase and nuclear factor-kappaB/Rel in lipopolysaccharide-stimulated macrophages

We show that radicicol, a fungal antibiotic, produces a marked inhibition of p38 kinase, nuclear factor-kappaB/Rel (NF-kappaB/Rel), and inducible nitric-oxide synthase (iNOS) transcription by the macrophage line RAW 264.7 in response to lipopolysaccharide (LPS). Treatment of RAW 264.7 with radicicol inhibited LPS-stimulated p38 kinase phosphorylation in a dose-related manner. iNOS transcription, which is regulated in part by the NF-kappaB/Rel family of transcription factors, has been shown to be under the control of the p38 kinase signaling cascade. Our data also show that the p38 kinase pathway is specifically involved in LPS-induced NF-kappaB/Rel activation and iNOS expression because NF-kappaB/Rel DNA binding and iNOS mRNA production in the presence of a specific inhibitor of p38 kinase, SB203580, were dramatically diminished. In contrast, PD98059, a specific inhibitor of mitogen-activated protein kinase/extracellular signal-regulated protein kinase kinase 1 had no effect on NF-kappaB/Rel activation and iNOS expression. LPS-induced loss of inhibitory proteins IkappaB-alpha and IkappaB-beta and translocation of p65, c-Rel, and p50 was inhibited by radicicol. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking p38 kinase signaling. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of radicicol on iNOS suggest that this potent antifungal agent may represent a useful anti-inflammatory agent.

Paclitaxel causes mouse splenic lymphocytes to a state hyporesponsive to lipopolysaccharide stimulation

Multiple immune system actions have been ascribed to paclitaxel (taxol), a novel anticancer drug, including the capacity to induce macrophage antitumor cytotoxic molecule production. In the present studies, we demonstrated that paclitaxel produced a selective inhibition of lipopolysaccharide (LPS)-induced B cell proliferation. Similarly, in vitro polyclonal antibody-forming cell responses also were found to be inhibited by paclitaxel. Conversely, paclitaxel exhibited no inhibitory effects on concanavalin A (Con A)-induced T cell proliferation. To study the pathway leading to paclitaxel-induced immunosuppression, we analyzed Raf-1/ERK and JNK/p38 MAPK pathways, both of which have been reported to be involved in LPS signaling. Our results indicate that taxol treatment inhibits Raf-1 kinase activation while having no effect on ERK activation suggesting that ERK activation is distinct from upstream Raf-1 kinase in taxol-induced immunomodulation. Furthermore, paclitaxel pretreatment caused down-regulation of stress-activated MAPKs, JNK and p38 MAPK in lipopolysaccharide (LPS)-stimulated mouse splenic lymphocytes, demonstrating that spleen cells are induced to a state hyporesponsive to LPS stimulation by pre-exposing them to paclitaxel. Taken together, these results suggest that down-regulation of JNK/p38 MAP kinase may contribute to paclitaxel-induced immunosuppression in mouse splenic lymphocytes.

Dexamethasone inhibits IL-1 beta gene expression in LPS-stimulated RAW 264.7 cells by blocking NF-kappa B/Rel and AP-1 activation

In the present study, the mechanism by which dexamethasone (DEX) inhibited IL-1beta gene expression in bacterial lipopolysaccharide (LPS)-activated RAW 264.7 cells was investigated. The decrease in LPS-induced IL-1beta mRNA expression was demonstrated by quantitative reverse transcription polymerase chain reaction (RT-PCR). Since the promoter in IL-1beta gene contains binding motifs for NF-kappaB/Rel, AP-1, NF-IL6, and CREB/ATF, which appear to be important in LPS-mediated IL-1beta induction, the effects of DEX on the activation of these transcription factors were examined. Treatment of DEX to RAW 264.7 cells induced a dose-related inhibition of NF-kappaB/Rel and AP-1 in chloramphenicol acetyltransferase activity, while neither NF-IL6 nor CREB/ATF activation was affected by DEX. Treatment of RAW 264.7 cells with DEX inhibited DNA binding of NF-kappaB/Rel and AP-1 proteins to their cognate DNA sites as measured by electrophoretic mobility shift assay (EMSA). DEX treatment caused a significant reduction in nuclear c-rel, p65, and p50 protein contents, and these decreases were paralleled by the accumulation of cytoplasmic c-rel, p65, and p50. DEX treatment of RAW 264.7 cells did not inhibit the nuclear translocation of c-jun and c-fos. We found that the inhibition of IL-1beta production by DEX is not related to p38, which is important in the IL-1beta induction. These results suggest that DEX may inhibit IL-1beta gene expression by a mechanism involving the blocking of LPS-induced NF-kappaB/Rel and AP-1 activation.

A new SUMO-1-specific protease, SUSP1, that is highly expressed in reproductive organs

A full-length cDNA encoding a SUMO-1-specific protease, named SUSP1, was identified and cloned for the first time from the human brain. Nucleotide sequence analysis of the cDNA containing an open reading frame of 3336 base pairs revealed that the protease consists of 1112 amino acids with a calculated molecular mass of 126,116 Da. Like yeast Ulp1, SUSP1 is a cysteine protease containing the well conserved His/Asp/Cys catalytic triad. SUSP1 expressed in Escherichia coli cells efficiently released SUMO-1 from SUMO-1. beta-galactosidase fusion but not from other ubiquitin-like protein fusions, including Smt3.beta-galactosidase, suggesting its role in the generation of matured SUMO-1 specifically from its precursors. Interestingly, reproductive organs, such as testis, ovary, and prostate, contained much higher amounts of SUSP1 mRNA than colon and peripheral blood leukocyte, whereas other tissues, such as heart and spleen, had little or none. In addition, confocal microscopy using green fluorescent protein.SUSP1 fusion showed that SUSP1 is exclusively localized to the cytoplasm of NIH3T3 and HeLa cells. These results suggest that SUSP1 may play a role in the regulation of SUMO-1-mediated cellular processes particularly related to reproduction.

Suppression of IL-2 and IL-4 gene expression by nodularin through the reduced NF-AT binding activity

Nodularin is a cyclic peptide produced by cyanobacteria. In the present study, the inhibitory effect of nodularin on T lymphocyte functions was demonstrated. Direct addition of nodularin to B6C3F1 mouse splenocyte cultures produced a concentration-dependent inhibition of the lymphoproliferative response to concanavalin A stimulation. Nodularin inhibited PMA plus ionomycin (Io)-induced IL-2 mRNA expression in murine splenocytes and thymocytes as determined by quantitative/competitive RT-PCR. To further characterize the mechanism for the transcriptional regulation of IL-2, the binding activity of transcription factors, NF-AT, AP-1, NF-kappaB, and Oct, was evaluated by electrophoretic mobility shift assays in mouse splenocytes. Nodularin reduced the NF-AT binding activity in PMA/Io-induced splenocytes, but no significant effect was observed on AP-1, NF-kappaB, or Oct binding activity. Nodularin also inhibited IL-4 mRNA expression in PMA/Io-stimulated murine splenocytes. These results suggest that T lymphocyte is a possible cellular target of nodularin, and the inhibitory effect of nodularin on T-cell specific transcription factor NF-AT induces T-cell dysfunction, which leads to a diminution in IL-2 and IL-4 gene transcription.

Effect of extracellular cations on the chemotherapeutic efficacy of anticancer drugs

Cancer development and the efficiency of chemotherapy relies on the patients calcium-related pathological status such as hyper- or hypocalcemia. In the present study, we investigated the effect of extracellular cations such as calcium and magnesium on the therapeutic efficacy of antitumor drugs. The analytic parameters used were cellular drug uptake/excretion and the chemosensitivity of the human breast cancer cell lines, MCF7 and MCF7/ADR. Both calcium and magnesium ions decreased the membrane permeability of cancer cells, which was determined by cell size analysis. These divalent ions also lowered the drug uptake and the cytoplasmic levels of rhodamine 123 and adriamycin, suggesting that they might interfere with the diffusion of these drugs by modifying the physical properties of the cytoplasmic membrane. The acute cytotoxicity of adriamycin after a short period of incubation correlated with changes in its cytoplasmic level. Our results indicate that these extracellular cations might play an important role in the therapeutic activities of anticancer drugs in cancer patients. These results also provide insight a new aspect of chemotherapy, because they suggest that the therapeutic doses of anti-cancer drugs should be modified in cancer-bearing patients presenting with abnormal blood calcium levels.

Photonic defect modes of cholesteric liquid crystals

We investigate defect modes of cholesteric liquid crystals as photonic band gap materials. For normal incidence of light, cholesteric liquid crystals exhibit total reflection for the circular polarization with the same handedness as that of cholesteric helix. However, the other orthogonal component is completely transmitted. When we replace a thin layer of liquid crystal by an isotropic material as a defect, defect modes are induced for both polarizations of incident light. We analyze the wavelength and reflectivity of the defect modes in terms of the refractive index of defect layer.

Cytotoxicity of urushiols isolated from sap of Korean lacquer tree (Rhus vernicifera Stokes)

Cytotoxicities of four urushiols, congeners isolated from the sap of Korean lacquer tree (Rhus vernicifera Stokes), to 29 human cancer cell lines originated from 9 organs were evaluated. Their values of 50% growth inhibition were below 4 microg/ml, and showed cell line specific cytotoxicity. The present result is the first report on the cytotoxicity of urushiols suggesting that they would have an anticancer activity to human cancer cells.

Protection of mice against P. aeruginosa infections by large-scale affinity-purified human IgG specific to P. aeruginosa outer membrane proteins

In order to develop an effective means to treat Pseudomonas aeruginosa infections, we designed a large-scale process for purification of human IgG specific to P. aeruginosa outer membrane proteins (Oprs) from normal human sera. The process we developed includes affinity column chromatography using P. aeruginosa Oprs as ligands, protein A column chromatography and ultrafiltration, which enriched P. aeruginosa Oprs-specific IgG antibody by 500-fold. The purified anti-Oprs IgG was specific to the Oprs as confirmed by an ELISA competition assay and retained opsonophagocytic-killing capacity. In vivo protective efficacy of anti-Oprs IgG was evaluated by passive protection assays in mice where the 50% protective dose of anti-Oprs IgG against P. aeruginosa infections was 41 microg/kg, which was 20 times lower than that of normal serum IgG. When administered to mice 3 h after bacterial challenge, only anti-Oprs IgG afforded protection. These data demonstrate the feasibility of use of the purification process in producing functionally active target-specific human antibodies for clinical use and provide a rationale for use of anti-Oprs IgG as a valuable adjunct to treat P. aeruginosa infections.

Suppression of the interleukin-2 gene expression by aflatoxin B1 is mediated through the down-regulation of the NF-AT and AP-1 transcription factors

The effect of aflatoxin B1 (AFB1) on the interleukin-2 (IL-2) gene expression was investigated in thymocytes of B6C3F1 mice, Jurkat E6-1 human T-cell leukemia, and EL4.IL-2 murine thymoma. AFB1 inhibited the phorbol-12myristate-13-acetate/i6nomycin (PMA/Io)-induced IL-2 mRNA expression in the murine thymocytes and Jurkat E6-1 cells as determined by qualitative RT-PCR, while no effect was observed in the EL4.IL-2 cells. Electrophoretic mobility shift assay indicated that AFB1 treatment showed an inhibition of the NF-AT and AP-1 DNA binding in PMA/Io-stimulated thymocytes and Jurkat E6-1 cells. No effect was observed on the Oct and NF-kappaB DNA binding. Employing a reporter gene expression system with p(NF-AT)3-CAT and p(AP-1)3-CAT, treatment with AFB1 to the transfected Jurkat E6-1 cells also showed an inhibition of the PMA/Io-induced NF-AT/CAT and AP-1/CAT activities. These results suggest that suppression of the IL-2 gene expression by AFB1 is mediated through the down-regulation of the NF-AT and AP-1 activation.

Activation of NF-kappaB/Rel in angelan-stimulated macrophages

In our previous studies we showed that the primary target cell of angelan, a polysaccharide purified from Angelica gigas Nakai, is a macrophage (Han et al., 1998). In the present study we examined the effect of angelan on iNOS, IL-1beta, and TNF-alpha transcription in mouse macrophage line RAW 264.7. We show that angelan produces a marked induction of iNOS, IL-1beta, and TNF-alpha transcription by RAW 264.7 cells. Since these gene transcriptions have been recently shown to be under the control of NF-kappaB/Rel family of transcription factors, we assessed the effect of angelan on NF-kappaB/Rel using a electrophoretic mobility shift assay. Treatment of RAW 264.7 cells with angelan produced strong induction of NF-kappaB/Rel binding. Treatment of RAW 264.7 cells with angelan slightly induced AP-1 binding activity, whereas Oct binding was not affected by angelan. Angelan stimulated macrophages to activate NF-kappaB/Rel, whereas neither B-cells nor T-cells were affected by the angelan. In conclusion, we demonstrate that the stimulation effect of angelan on macrophage is mediated by specific activation of NF-kappaB/Rel.

Induction of inducible nitric oxide synthase gene expression by Pokeweed mitogen

The present study has characterized the expression of iNOS gene in Pokeweed mitogen (PWM)-driven murine macrophage RAW 264.7 cells. PWM significantly induced nitric oxide production in a dose-dependent manner. Quantitative reverse transcription-polymerase chain reaction analysis demonstrated that the inducible nitric oxide synthase gene expression is increased by PWM treatment. Since iNOS transcription has recently been shown to be under the control of the nuclear factor (NF)-kappaB/Rel family of transcription factors, the effects of PWM on NF-kappaB/Rel activation were examined using a transient transfection assay and an electrophoretic mobility shift assay (EMSA). Transient expression assays with NF-kappaB/Rel binding sites linked to the chloramphenicol acetyltransferase gene suggest that the PWM-induced increase in transcription is mediated by the NF-kappaB/Rel transcription factor complex. Using DNA fragments containing the NF-kappaB/Rel binding sequence, PWM was shown to activate the protein/DNA binding of NF-KB/Rel to its cognate site as measured by EMSA. Supershift EMSA showed the presence of p50 and c-Rel protein in the complex at the kappaB site. Western blot analysis of isolated nuclear fractions, using p65 and c-Rel-specific antibodies, provided further evidence that c-Rel is increased by PWM treatment. N-Tosyl-1-phenylalanine chloromethyl ketone, a potent inhibitor of NF-kappaB/Rel activation, inhibited PWM-induced nitrite generation in a dose-dependent manner. Collectively, the results of these experiments indicate that c-Rel is positively regulated by PWM to assist in the initiation of iNOS gene expression.

Acetylaminofluorene inhibits nitric oxide production in LPS-stimulated RAW 264.7 cells by blocking NF-kappa B/Rel activation

The mechanism by which 2-acetylaminofluorene (AAF) inhibited nitric oxide (NO) formation, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was investigated. The decrease in NO, as demonstrated by measurement of nitrite was found to correlate well with a decrease in inducible nitric oxide synthase (iNOS) mRNA. Since the promoter in iNOS gene contains binding motifs for NF-kappa B/Rel, AP-1, and NF-IL6 which appear to be important for LPS-mediated iNOS induction, the effect of AAF on the activation of these transcription factors was determined. Treatment of AAF to RAW 264.7 cells induced a dose-related inhibition of NF-kappa B/Rel in chloramphenicol acetyltransferase activity, while either AP-1 or NF-IL6 activation was not affected by AAF. Treatment of RAW 264.7 cells with AAF inhibited protein/DNA binding of NF-kappa B/Rel to its cognate site as measured by electrophoretic mobility shift assay. In addition, AAF treatment caused a significant reduction of nuclear c-rel, p65, and p50 protein levels, and this decrease was paralleled by the accumulation of cytoplasmic c-rel, p65, and p50. These data suggest that AAF inhibits iNOS gene expression by a mechanism involving a blockade of LPS-induced nuclear translocation of NF-kappa B/Rel.

The inhibitory effect of polysaccharides isolated from Phellinus linteus on tumor growth and metastasis

It was previously reported that polysaccharides (PL) isolated from Phellinus linteus strongly stimulated cell-mediated and humoral immunity. This study was undertaken to investigate the immunochemotherapeutic activity of PL against tumor growth and metastasis. PL alone significantly prolonged the survival rate of B16F10-implanted mice, inhibited tumor growth in NCI-H23-implanted nude mice, and reduced the frequency of pulmonary metastasis of B16F10 melanoma. Adriamycin significantly inhibited tumor growth, but only slightly inhibited metastasis. The combination therapy with PL and adriamycin was more effective in inhibiting tumor growth, but not metastasis. PL did not induce direct toxicity in cancer cells, which is characteristic of immunotherapeutics. In conclusion, PL might be of use in immunochemotherapy of cancer because of its effective activities on tumor growth and metastasis through the immunopotentiation of the patients without toxicity.

Down-regulation of protein kinase C: a potential mechanism for 2-amino-3-methylimidazo[4,5-f]quinoline-mediated immunosuppression

Immunosuppressive mechanism of food-born mutagenic and carcinogenic heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), was studied in murine spleen cells. IQ suppressed the IL-2 secretion and its mRNA expression. Treatment of IQ also decreased PKC activity in both the membrane fraction and the cytosol fraction. Treatment of PMA resulted in the recovery of IQ-induced suppression of IL-2 production, but the addition of ionomycin (Io) had no effect. Subsequently, we examined the effect of IQ on the activation of NF-kappaB, AP-1, and NF-AT, which are key transcription factors for IL-2 transcription. The activation of NF-kappaB and AP-1 was markedly inhibited by IQ in PMA/PHA-stimulated cells. Meanwhile, NF-AT was not affected by IQ in PMA/Io-stimulated cells. These results suggest that the immunosuppression induced by IQ might be associated with the down-regulation of PKC and subsequent blockade of the activation of NF-kappaB and AP-1 in the IL-2 gene expression.

Transforming growth factor-beta 1 (TGF-beta1) promotes IL-2 mRNA expression through the up-regulation of NF-kappaB, AP-1 and NF-AT in EL4 cells

Transforming growth factor beta1 (TGF-beta1) has been previously shown to modulate interleukin 2 (IL-2) secretion by activated T-cells. In the present studies, we determined that TGF-beta1 induced IL-2 mRNA expression in the murine T-cell line EL4, in the absence of other stimuli. IL-2 mRNA expression was significantly induced by TGF-beta1 (0.1-1 ng/ml) over a relatively narrow concentration range, which led to the induction of IL-2 secretion. Under identical condition, we examined the effect of TGF-beta1 on the activity of nuclear factor AT (NF-AT), nuclear factor kappaB (NF-kappaB), activator protein-1 (AP-1) and octamer, all of which contribute to the regulation of IL-2 gene expression. Electrophoretic mobility shift assays showed that TGF-beta1 markedly increased NF-AT, NF-kappaB and AP-1 binding to their respective cognate DNA binding sites, whereas octamer binding remained constant, as compared with untreated cells. Employing a reporter gene expression system with p(NF-kappaB)3-CAT, p(NF-AT)3-CAT and p(AP-1)3-CAT, TGF-beta1 treatment of transfected EL4 cells induced a dose-related increase in chloramphenicol acetyltransferase activity that correlated well with the DNA binding profile found in the electrophoretic mobility shift assay studies. These results show that TGF-beta1, in the absence of any additional stimuli, up-regulates the activity of key transcription factors involved in IL-2 gene expression, including NF-AT, NF-kappaB and AP-1, to help promote IL-2 mRNA expression by EL4 cells.

Inhibition of NF-kappa B/Rel nuclear translocation by dexamethasone: mechanism for the inhibition of iNOS gene expression

The decrease in NO production was found to correlate well with a decrease in inducible nitric oxide synthase (iNOS) mRNA expression as demonstrated by Northern blot analysis and quantitative RT-PCR. Since the promoter in iNOS gene contains binding motifs for NF-kappa B/Rel, NF-IL6, and Oct which appear to be important for LPS-mediated iNOS induction, the effects of DEX on the activation of these transcription factors were examined. Treatment of DEX to RAW 264.7 cells induced a dose-related inhibition of NF-kappa B/Rel in chloramphenicol acetyltransferase activity, while NF-IL6 or Oct activation was not affected by DEX. Treatment of RAW 264.7 cells with DEX inhibited DNA binding of NF-kappa B/Rel proteins to their cognate DNA site as measured by electrophoretic mobility shift assay. In addition, DEX treatment caused a significant reduction in nuclear c-rel, p65, and p50 protein contents, and these decreases were paralleled by the accumulation of cytoplasmic c-rel, p65, and p50. These results suggest that DEX may inhibit iNOS gene expression by a mechanism involving the blockade of LPS-induced nuclear translocation of NF-kappa B/Rel.

The effect of 2-mercapto-5-methyl-1,3,4-thiadiazole on enzymatic synthesis of cefazolin

The effect of unreacted residual 2-mercapto-5-methyl-1,3,4-thiadiazole (MMTD), the reagent for 3-[5-methyl-1,3,4-thiadiazole-2-yl]-7-aminocephalosporanic acid (M-7-ACA) synthesis, on the enzymatic acylation of M-7-ACA by the methyl ester of 1,2,3,4-tetrazol-1-acetic acid (MeTzAA) to produce cefazolin (CEZ) was studied. In the two-step process of synthesizing CEZ from 7-aminocephalosporanic acid (7-ACA), one of the key parameters controlling the overall CEZ yield was the ratio of MMTD to 7-ACA in M-7-ACA synthesis. The increase of the ratio showed opposing effects by increasing the M-7-ACA yield in the first step, while decreasing CEZ yield in the subsequent enzymatic reaction by the inhibitory effect of the increased content of MMTD as an impurity in the M-7-ACA preparation. It was revealed that the decrease of CEZ yield in the enzymatic reaction was caused by the selective retardation of the rate of CEZ synthesis reaction by a typical competitive inhibition, while not affecting the rate of MeTzAA hydrolysis reaction. The optimum MMTD-to-7-ACA ratio rendering the highest overall CEZ yield over 7-ACA was 1.2:1.

Induction of liver-associated transforming growth factor beta 1 (TGF-beta 1) mRNA expression by carbon tetrachloride leads to the inhibition of T helper 2 cell-associated lymphokines

Acute treatment of B6C3F1 mice with a hepatotoxic dose (500 mg/kg) of carbon tetrachloride (CCl4) produced a marked but transient increase in transforming growth factor beta 1 (TGF-beta 1) mRNA expression in the liver within 24 hr. We have previously shown that an identical dose of CCl4 also produces a marked increase in serum TGF-beta 1 concentrations which peak at 48 hr and produce a marked inhibition of the anti-sRBC IgM antibody forming cell (AFC) response. Similar increases in TGF-beta 1 transcripts scripts in the liver were also induced by an acute hepatotoxic dose (600 mg/kg) of acetaminophen. No increase in TGF-beta 1 mRNA expression was detected in the spleen following treatment with either agent. Direct addition of TGF-beta 1 (0.05-1.0 ng/ml) to naive splenocyte cultures produced a marked and dose-related inhibition of the anti-sRBC IgM AFC response. Under the same conditions, TGF-beta 1 induced a marked decrease in IL-4 and IL-5 mRNA expression in sRBC-sensitized splenocytes. Concomitantly, TGF-beta 1 induced a rapid increase in NF-kappa B/Rel trans-acting factor binding within the first 24 hr post-sRBC sensitization of splenocytes. Conversely, NF-kappa B/Rel binding activity was inhibited on Days 2 through 4 in sRBC-sensitized splenocytes in the presence of TGF-beta 1. The increase in NF-kappa B/Rel binding within 24 hr following sRBC sensitization is consistent with the positive influence TGF-beta 1 exerts on Th1 cytokines such as IL-2 and IFN-gamma. Conversely the decrease in NF-kappa B/Rel binding at the later time period during the AFC response (Days 2-4) coincides with the inhibitory effects TGF-beta 1 exerted on IgM production by B cells.

Expression of estrogen receptors in a normal human breast epithelial cell type with luminal and stem cell characteristics and its neoplastically transformed cell lines

Although approximately two-thirds of breast cancers are estrogen receptor (ER)-positive, only a small proportion of epithelial cells in the mammary gland express the ER. The origin of the ER-positive breast cancers is unknown. Recently, we have developed a culture method to grow two morphologically and antigenically distinguishable types of normal human breast epithelial cells (HBEC) derived from reduction mammoplasty. In this report, we studied the expression of ER in these two types of cells and their transformed cell lines. The results indicate that Type I HBEC with luminal and stem cell characteristics expressed a variant ER (approximately 48 kd) by Western blot analysis. This variant ER contains a deletion in the DNA binding domain (exon 2) as revealed by RT-PCR analysis. The lack of the DNA-binding domain of the variant ER was also confirmed by the ER-estrogen responsive element binding assay, as well as by the immunofluorescence staining of the ER using anti-ER antibodies which recognize either the C-terminal or N-terminal region. In contrast, Type II HBEC with basal epithelial phenotype are ER-negative. Simian virus 40 (SV40) transformed Type I and Type II HBEC lines also expressed the variant ER. Tumors formed in athymic nude mice by in vitro transformed tumorigenic Type I cell lines, however, expressed a high level of wild type ER which was undetectable in these cells grown in vitro before and after tumor formation. Thus, there appears to be a differential ER mRNA splicing between the in vitro and in vivo mileu.