Single-crystalline iridium dioxide nanowires show the time-dependent universal conductance fluctuations (TUCFs) at cryogenic temperatures. The conductance fluctuations persist up to temperature T as high as nearly 10 K. The root-mean-square TUCF magnitudes increase with decreasing T, reaching approximately 0.1 e2 / h at 1.7 K. We ascribe these conductance fluctuations to originating from the conduction electrons scattering upon mobile defects (moving scattering centers). Our measured TUCF characteristics are satisfactorily explained in terms of the existing TUCF theory in its three-dimensional form. The extracted electron dephasing length Lφ(1.7 K) ≃90 nm is smaller than the diameter (≈ 180 nm) of our nanowires.
Quantum-interference effect; Universal conductance fluctuation; Mobile defect; Iridium dioxide nanowire; Rutile structure
Transport of newly synthesized Rhodopsin upon light stimulation in adult Drosophila photoreceptors is mediated by a Crag/Rab11-dependent vesicular trafficking process.
Rhodopsins (Rhs) are light sensors, and Rh1 is the major Rh in the Drosophila photoreceptor rhabdomere membrane. Upon photoactivation, a fraction of Rh1 is internalized and degraded, but it remains unclear how the rhabdomeric Rh1 pool is replenished and what molecular players are involved. Here, we show that Crag, a DENN protein, is a guanine nucleotide exchange factor for Rab11 that is required for the homeostasis of Rh1 upon light exposure. The absence of Crag causes a light-induced accumulation of cytoplasmic Rh1, and loss of Crag or Rab11 leads to a similar photoreceptor degeneration in adult flies. Furthermore, the defects associated with loss of Crag can be partially rescued with a constitutive active form of Rab11. We propose that upon light stimulation, Crag is required for trafficking of Rh from the trans-Golgi network to rhabdomere membranes via a Rab11-dependent vesicular transport.
Animals sense light through receptors called Rhodopsins. These proteins are typically localized to stacked membranes in photoreceptors. In flies, upon light exposure, Rhodopsin undergoes conformational changes and becomes active as metarhodopsin. Metarhodopsin then initiates a signaling cascade that activates the photoreceptor cell. To deactivate the light response, metarhodopsin is converted back into Rhodopsin by absorption of another photon of light. Under certain conditions, metarhodopsin cannot be converted back to Rhodopsin, and it is then endocytosed and degraded. Rhodopsin then needs to be synthesized and delivered back to the membrane stacks. Here, we show that the Calmodulin-binding protein Crag is required for the delivery of newly made Rhodopsin to the membrane stacks. Loss of Crag leads to the accumulation of Rhodopsin in the cytosol, followed by shrinkage of membrane stack volume, and, eventually, photoreceptor cell degeneration. We also show that Crag activates a target protein, Rab11, which mediates the vesicular transport of Rhodospin to the membrane. Finally, we document that the human homolog of Crag, DENND4A, is able to rescue the loss of Crag in flies, suggesting that DENND4A functions in a similar process in vertebrates.
Deoxybostrycin (1) is an anthraquinone compound derived from the marine mangrove fungus Nigrospora sp. No. 1403 and has potential to be a lead for new drugs because of its various biological properties. A series of new derivatives (2–22) of deoxybostrycin were synthesized. The in vitro cytotoxicity of all the new compounds was tested against MDA-MB-435, HepG2 and HCT-116 cancer cell lines. Most of the compounds exhibit strong cytotoxicity with IC50 values ranging from 0.62 to 10 μM. Compounds 19, 21 display comparable cytotoxicity against MDA-MB-435 to epirubicin, the positive control. The primary screening results indicate that the deoxybostrycin derivatives might be a valuable source of new potent anticancer drug candidates.
deoxybostrycin derivatives; antitumor activity; marine mangrove; anthraquinone
Despite extensive research and interest in endocrine disruptors, there are essentially no epidemiologic studies of estrogenic mycotoxins, such as zeranol and zearalenone (ZEA). ZEA mycoestrogens are present in grains and other plant foods through fungal contamination, and in animal products (e.g., meat, eggs, dairy products) through deliberate introduction of zeranol into livestock to enhance meat production, or by indirect contamination of animals through consumption of contaminated feedstuff. Zeranol is banned for use in animal husbandry in the European Union and other countries, but is still widely used in the US. Surprisingly, little is known about the health effects of these mycoestrogens, including their impact on puberty in girls, a period highly sensitive to estrogenic stimulation.
OBJECTIVES AND METHODS
We conducted a cross-sectional analysis among 163 girls, aged 9 and 10 years, participating in the Jersey Girl Study to measure urinary mycoestrogens and their possible relationship to body size and development.
We found that mycoestrogens were detectable in urine in 78.5% of the girls, and that urinary levels were predominantly associated with beef and popcorn intake. Furthermore, girls with detectable urinary ZEA mycoestrogen levels tended to be shorter and less likely to have reached the onset of breast development.
Our findings suggest that ZEA mycoestrogens may exert anti-estrogenic effects similar to those reported for isoflavones. To our knowledge, this was the first evaluation of urinary mycoestrogens and their potential health effects in healthy girls. However, our findings need replication in larger studies with more heterogeneous populations, using a longitudinal approach.
mycoestrogens; zearalenone; zeranol; thelarche; height; weight
Radiation therapy is commonly used to treat localized prostate cancer; however, representative data regarding treatment-related toxicities compared with conservative management are sparse.
To evaluate gastrointestinal (GI) toxicities in men treated with either primary radiation or conservative management for T1–T2 prostate cancer.
Design, setting, and participants
We performed a population-based cohort study, using Medicare claims data linked to the Surveillance Epidemiology and End Results data. Competing risk models were used to evaluate the risks.
GI toxicities requiring interventional procedures occurring at least 6 mo after cancer diagnosis.
Results and limitations
Among 41 737 patients in this study, 28 088 patients received radiation therapy. The most common GI toxicity was GI bleeding or ulceration. GI toxicity rates were 9.3 per 1000 person-years after three-dimensional conformal radiotherapy, 8.9 per 1000 person-years after intensity-modulated radiotherapy, 5.3 per 1000 person-years after brachytherapy alone, 20.1 per 1000 person-years after proton therapy, and 2.1 per 1000 person-years for conservative management patients. Radiation therapy is the most significant factor associated with an increased risk of GI toxicities (hazard ratio [HR]: 4.74; 95% confidence interval [CI], 3.97–5.66). Even after 5 yr, the radiation group continued to experience significantly higher rates of new GI toxicities than the conservative management group (HR: 3.01; 95% CI, 2.06–4.39). Because our cohort of patients were between 66 and 85 yr of age, these results may not be applicable to younger patients.
Patients treated with radiation therapy are more likely to have procedural interventions for GI toxicities than patients with conservative management, and the elevated risk persists beyond 5 yr.
Prostate cancer; Radiation therapy; Late gastrointestinal toxicity; Medicare; Surveillance Epidemiology and End Results program
We report on the first electrical characterizations of single-crystalline TiSi nanowires (NWs) synthesized by chemical vapor deposition reactions. By utilizing the focused-ion-beam-induced deposition technique, we have delicately made four-probe contacts onto individual NWs. The NW resistivities have been measured between 2 and 300 K, which reveal overall metallic conduction with small residual resistivity ratios in the NWs. Surprisingly, we find that the effect due to the interference processes between the elastic electron scattering and the electron-phonon scattering largely dominates over the usual Boltzmann transport even at room temperature. Such prominent electron-phonon-impurity interference effect is ascribed to the presence of large amounts of disorder and high Debye temperatures in TiSi NWs.
Chemical vapor deposition reaction; TiSi nanowire; Silicide; Electron-phonon scattering; Electron-phonon-impurity interference; Focused-ion-beam-induced deposition
Human papillomavirus (HPV) type-specific prevalence was studied in 600 cases of cervical intraepithelial neoplasm in western China by GenoArray test. HPV-16 and -58 were the most prevalent types, with prevalences of 37.8% and 21.8%, respectively. HPV-18 and -45 were uncommon types. The results show different type distributions from that of other regions, which is important evidence for the selection of future genotypes in HPV vaccines in western China.
Motivation: Several new de novo assembly tools have been developed recently to assemble short sequencing reads generated by next-generation sequencing platforms. However, the performance of these tools under various conditions has not been fully investigated, and sufficient information is not currently available for informed decisions to be made regarding the tool that would be most likely to produce the best performance under a specific set of conditions.
Results: We studied and compared the performance of commonly used de novo assembly tools specifically designed for next-generation sequencing data, including SSAKE, VCAKE, Euler-sr, Edena, Velvet, ABySS and SOAPdenovo. Tools were compared using several performance criteria, including N50 length, sequence coverage and assembly accuracy. Various properties of read data, including single-end/paired-end, sequence GC content, depth of coverage and base calling error rates, were investigated for their effects on the performance of different assembly tools. We also compared the computation time and memory usage of these seven tools. Based on the results of our comparison, the relative performance of individual tools are summarized and tentative guidelines for optimal selection of different assembly tools, under different conditions, are provided.
Supplementary information: Supplementary data are available at Bioinformatics online.
In the preclinical setting, phosphorylation and subsequent proteosomal degradation of the proapoptotic protein BIM confers resistance to paclitaxel in solid tumors with RAS/RAF/MAPK pathway activation. Concurrent administration of the proteasome inhibitor bortezomib enables paclitaxel-induced BIM accumulation, restoring cancer cell apoptosis in vitro and producing tumor regression in mice in vivo. A Phase I study was conducted to determine the MTD of paclitaxel and bortezomib combinatorial treatment. Sixteen patients with refractory solid tumors commonly exhibiting MAPK pathway activation were treated with weekly paclitaxel and bortezomib. Starting doses were 40 mg/m2 for paclitaxel and 0.7 mg/m2 for bortezomib. A modified continual reassessment method (MCRM) adapted for 2-drug escalation was used for MTD determination with 3-patient cohorts treated at each dose level. MTD was reached at 60 mg/m2 paclitaxel and 1.0 mg/m2 bortezomib, the recommended phase II dose. Therapy was overall well tolerated. Most frequently observed toxicities included anemia (in 43.75% of patients, one Grade 3 event), fatigue (in 43.75% of patients, one Grade 3 event beyond cycle 1) and neuropathy (in 31.25% of patients, one Grade 3 event after cycle 1). Of 15 evaluable patients, one NSCLC patient with paclitaxel exposure at the adjuvant setting had a PR and five patients had SD; median disease stabilization was 143.5 days; three NSCLC patients had SD lasting 165 days or longer. Thus, rationally designed weekly treatment with paclitaxel and bortezomib in solid tumors with MAPK pathway activation, including previously taxane-treated malignancies, is a tolerable regimen with preliminary signals of antitumor activity worthy of further investigation.
MAPK; paclitaxel; bortezomib; BIM; apoptosis
To evaluate the U.K. Prospective Diabetes Study (UKPDS) and Framingham risk equations for predicting short-term risk of coronary heart disease (CHD) events among adults with long-standing type 2 diabetes, including those with and without preexisting CHD.
Prospective cohort of U.S. managed care enrollees aged ≥ 18 years and mean diabetes duration of more than 10 years, participating in the Translating Research into Action for Diabetes (TRIAD) study, was followed for the first occurrence of CHD events from 2000 to 2003. The UKPDS and Framingham risk equations were evaluated for discriminating power and calibration.
A total of 8303 TRIAD participants, were identified to evaluate the UKPDS (n = 5914, 120 events), Framingham-initial (n = 5914, 218 events) and Framingham-secondary (n = 2389, 374 events) risk equations, according to their prior CHD history. All of these equations exhibited low discriminating power with Harrell’s c-index <0.65. All except the Framingham-initial equation for women and the Framingham-secondary equation for men had low levels of calibration. After adjsusting for the average values of predictors and event rates in the TRIAD population, the calibration of these equations greatly improved.
The UKPDS and Framingham risk equations may be inappropriate for predicting the short-term risk of CHD events in patients with long-standing type 2 diabetes, partly due to changes in medications used by patients with diabetes and other improvements in clinical care since the Frmaingham and UKPDS studies were conducted. Refinement of these equations to reflect contemporary CHD profiles, diagnostics and therapies are needed to provide reliable risk estimates to inform effective treatment.
Our previous studies reported that caffeine or voluntary exercise decreased skin tumor multiplicity, in part, by decreasing fat levels in the dermis. These data suggest that tissue fat may play an important role in regulating ultraviolet light (UV) B-induced skin tumor development. In the present study, we explored the effects of high-fat diets rich in either omega-3 or omega-6 fatty acids on UVB-induced skin carcinogenesis. SKH-1 mice were irradiated with 30 mJ/cm2 of UVB once a day, two times per week for 39 weeks. During UVB treatment, one group of mice was given a high-fat fish oil (HFFO) diet rich in omega-3 fatty acids and the other group of mice was given a high-fat mixed-lipids (HFMLs) diet rich in omega-6 fatty acids. The results showed that, compared with HFML diet, HFFO treatment (i) increased latency for the development of UVB-induced skin tumors; (ii) decreased the formation of papilloma, keratoacanthoma and carcinoma by 64, 52 and 46%, respectively and (iii) decreased the size of papilloma, keratoacanthoma and carcinoma by 98, 80 and 83%, respectively. Mechanistic studies with antibody array revealed that compared with HFML diet, administration of HFFO to the mice significantly decreased the UVB-induced increases in the levels of TIMP-1, LIX and sTNF R1 as well as other several proinflammatory cytokines and stimulated the UVB-induced apoptosis in the epidermis. Our results indicate that omega-3 fatty acids in HFFO diet have beneficial effects against UVB-induced skin carcinogenesis, and these effects may be associated with an inhibition on UVB-induced inflammatory response.
The regulation of apoptosis is critical for controlling tissue homeostasis and preventing tumor formation and growth. Reactive Oxygen Species (ROS) generation plays a key role in such regulation. Here, we describe a HIF-1 target, ATIA (anti-TNFα-induced apoptosis), which protects cells against TNFα- and hypoxia-induced apoptosis. Through the generation of ATIA knockout mice, we show that ATIA protects cells from apoptosis through regulating the function of the mitochondrial antioxidant, thioredoxin-2, and ROS generation. ATIA is highly expressed in human glioblastoma and ATIA knockdown in glioblastoma cells renders them sensitive to hypoxia-induced apoptosis. Therefore, ATIA is not only a HIF-1 target that regulates mitochondrial redox pathways but a potentially diagnostic marker and therapeutic target in human glioblastoma.
Cyclotripeptide X-13 is a core of novel marine compound xyloallenoide A isolated from mangrove fungus Xylaria sp. (no. 2508). We found that X-13 dose-dependently induced angiogenesis in zebrafish embryos and in human endothelial cells, which was accompanied by increased phosphorylation of eNOS and Akt and NO release. Inhibition of PI3K/Akt/eNOS by LY294002 or L-NAME suppressed X-13-induced angiogenesis. The present work demonstrates that X-13 promotes angiogenesis via PI3K/Akt/eNOS pathways.
angiogenesis; marine cyclotripeptide; zebrafish; endothelial nitric oxide synthase; xyloallenoide A
There is accumulating epidemiologic evidence that exposure to traffic-related air pollutants, including particulate matter (PM) and polyaromatic hydro carbons (PAHs), plays a role in etiology and prognosis of a large scale of illnesses, although the role of specific causal agents and underlying mechanisms for different health outcomes remains unknown.
Our general objective was to assess the relations between personal exposure to traffic exhausts, in particular ambient PM2.5 and PAHs, and the occurrence of DNA strand breaks by applying personal monitoring of PM and biomarkers of exposure (urinary 1-hydroxypyrene-glucuronide, 1-OHPG) and effect (urinary 8-hydroxydeoxyguanosine, 8-OHdG and DNA strand breaks).
We recruited 91 traffic conductors and 53 indoor office workers between May 2009 and June 2011 in Taipei City, Taiwan. We used PM2.5 personal samplers to collect breathing-zone particulate PAHs samples. Spot urine and blood samples after work shift of 2 consecutive days were analyzed for 1-OHPG, 8-OHdG and DNA strand breaks, respectively. Statistical methods included linear regression and mixed models.
Urinary 8-OHdG levels and the occurrence of DNA strand breaks in traffic conductors significantly exceeded those in indoor office workers in mixed models. Particulate PAHs levels showed a positive association with urinary 1-OHPG in the regression model (β = 0.056, p = 0.01). Urinary 1-OHPG levels were significantly associated with urinary 8-OHdG levels in the mixed model (β = 0.101, p = 0.023). Our results provide evidence that exposure to fine particulates causes DNA damage. Further, particulate PAHs could be biologically active constituents of PM2.5 with reference to the induction of oxidative DNA damages.
Longitudinal associations between leisure-time physical activity (LTPA) and overall cancer mortality were evaluated within the Third National Health and Nutrition Examination Survey (NHANES III; 1988–2006; n = 15,535). Mortality status was ascertained using the National Death Index. Self-reported LTPA was divided into inactive, regular low-to-moderate and vigorous activity. A frequency-weighted metabolic equivalents (METS/week) variable was also computed. Hazard ratios (HRs) and 95% confidence intervals (CI) were calculated for overall cancer mortality in the whole sample, by body mass index categories and insulin resistance (IR) status. Nonsignificant protective associations were observed for regular low-to-moderate and vigorous activity, and for the highest quartile of METS/week (HRs range: 0.66–0.95). Individuals without IR engaging in regular vigorous activity had a 48% decreased risk of cancer mortality (HR: 0.52; 95% CI: 0.28–0.98) in multivariate analyses. Conversely, nonsignificant positive associations were observed in people with IR. In conclusion, regular vigorous activity may reduce risk of cancer mortality among persons with normal insulin-glucose metabolism in this national sample.
To provide patients and clinicians more accurate estimates of comorbidity-specific survival stratified by patient age, tumor stage, and tumor grade.
Patients and Methods
We conducted a 10-year competing risk analysis of 19,639 men 66 years of age and older identified by the Surveillance, Epidemiology, and End Results (SEER) program linked to Medicare program files. All men were diagnosed with localized prostate cancer and received no surgery or radiation within 180 days of diagnosis. The analysis was stratified by tumor grade and stage and by age and comorbidity at diagnosis classified using the Charlson comorbidity index. Underlying causes of death were obtained from SEER.
During the first 10 years after diagnosis, men with moderately and poorly differentiated prostate cancer were more likely to die from causes other than their disease. Depending on patient age, Gleason score, and number of comorbidities present at diagnosis, 5-year overall mortality rates for men with stage T1c disease ranged from 11.7% (95% CI, 10.2% to 13.1%) to 65.7% (95% CI, 55.9% to 70.1%), and prostate cancer–specific mortality rates ranged from 1.1% (95% CI, 0.0% to 2.7%) to 16.3% (95% CI, 13.8% to 19.4%). Ten-year overall mortality rates ranged from 28.8% (95% CI, 25.3% to 32.6%) to 94.3% (95% CI, 87.4% to 100%), and prostate cancer–specific mortality rates ranged from 2.0% (95% CI, 0.0% to 5.3%) to 27.5% (95% CI, 21.5% to 36.5%).
Patients and clinicians should consider using comorbidity-specific data to estimate the threat posed by newly diagnosed localized prostate cancer and the threat posed by competing medical hazards.
Although it is well known that epidermal growth factor receptor (EGFR) is involved in lung cancer progression, whether EGFR contributes to lung epithelial cell transformation is less clear. Mucin 1 (MUC1 in human and Muc1 in animals), a glycoprotein component of airway mucus, is overexpressed in lung tumors; however, its role and underlying mechanisms in early stage lung carcinogenesis is still elusive. This study provides strong evidence demonstrating that EGFR and MUC1 are involved in bronchial epithelial cell transformation. Knockdown of MUC1 expression significantly reduced transformation of immortalized human bronchial epithelial cells induced by benzo[a]pyrene diol epoxide (BPDE), the active form of the cigarette smoke (CS) carcinogen benzo(a)pyrene (BaP)s. BPDE exposure robustly activated a pathway consisting of EGFR, Akt and ERK, and blocking this pathway significantly increased BPDE-induced cell death and inhibited cell transformation. Suppression of MUC1 expression resulted in EGFR destabilization and inhibition of the BPDE-induced activation of Akt and ERK and increase of cytotoxicity. These results strongly suggest an important role for EGFR in BPDE-induced transformation, and substantiate that MUC1 is involved in lung cancer development, at least partly through mediating carcinogen-induced activation of the EGFR-mediated cell survival pathway that facilitates cell transformation.
In contrast to strong epidemiologic, preclinical, and secondary clinical evidence for vitamin E (tocopherols) in reducing cancer risk, large-scale clinical cancer-prevention trials of α-tocopherol have been negative. This vexing contrast helped spur substantial preclinical efforts to better understand and improve the antineoplastic activity of tocopherol through, for example, the study of different tocopherol forms. We previously showed that the γ-tocopherol–rich mixture (γ-TmT) effectively inhibited colon and lung carcinogenesis and the growth of transplanted lung-cancer cells in mice. We designed the present study to determine the relative activities of different forms of tocopherol in a xenograft model, comparing the anticancer activities of δ-tocopherol with those of α- and γ-tocopherols. We subcutaneously injected human lung cancer H1299 cells into NCr nu/nu mice, which then received α-, γ-, or δ-tocopherol or γ-TmT in the diet (each at 0.17% and 0.3%) for 49 days. δ-Tocopherol inhibited tumor growth most strongly. γ-Tocopherol and γ-TmT (at 0.3%) also inhibited growth significantly, but α-tocopherol did not. δ-Tocopherol also effectively decreased oxidative DNA damage and nitrotyrosine formation and enhanced apoptosis in tumor cells; again, γ-tocopherol also was active in these regards but less so, and α-tocopherol was not. Each supplemented diet increased serum levels of its tocopherol—up to 45 µM for α-tocopherol, 9.7 µM for γ-tocopherol, and 1.2 µM for δ-tocopherol; dietary γ- or δ-tocopherol, however, decreased serum α-tocopherol levels, and dietary α-tocopherol decreased serum levels of γ-tocopherol. Each dietary tocopherol also increased its corresponding side-chain–degradation metabolites, with concentrations of δ-tocopherol metabolites greater than γ-tocopherol and far greater than α-tocopherol metabolites in serum and tumors. The present study is the first in vivo assessment of δ-tocopherol in tumorigenesis and demonstrates that δ-tocopherol is more active than α- or γ-tocopherol in inhibiting tumor growth, possibly through trapping reactive oxygen and nitrogen species and inducing apoptosis; δ-tocopherol metabolites could contribute significantly to these results.
Tocopherols; lung cancer cells; xenograft; tocopherol metabolites
A recent study has indicated that alveolar macrophages from smokers incubated with lipopolysaccharide (LPS) secrete much more IL-1β and TNF-α than those from healthy nonsmokers, but the mechanisms underlying this augmented secretion by cigarette smoke (CS) remain unknown. CS and LPS reportedly promote macrophages' secreting substance P (SP) that could up-regulate these cytokines' secretion from macrophages by acting on neurokinin 1 receptor (NK1R). Moreover, NF-κB from macrophages participates in NK1R intracellular signaling and synthesis of these cytokines. The present in vitro study was undertaken to examine whether CS is able to synergize these cytokines' response to LPS in macrophages, and if so, whether an amplified SP secretion is responsible for this synergistic cytokines' response via a NK1R-driven NF-κB pathway. THP-1–derived and MH-S macrophages were exposed to control medium and CS condensate (CSC) without or with LPS. We found that LPS, CSC, and CSC+LPS significantly increased IL-1β, TNF-α, and SP secretion and that SP secretion markedly preceded cytokines' secretion. CSC+LPS-induced responses were markedly greater than the sum of the responses to CSC and LPS alone, suggesting a synergistic effect. Blocking NK1R reduced the responses of IL-1β, TNF-α, and NF-κB activation to CSC+LPS by 41, 40, and 46%, respectively. NF-κB inhibitors decreased the CSC+LPS–induced cytokines' responses by 70%. Our findings suggest that CS amplifies the LPS-induced macrophages' secretion of IL-1β and TNF-α through synergizing SP secretion, which activates NF-κB via binding with NK1R.
cytokines; infection; emphysema; signal pathway of NF-κB
Lung cancer ranks as the first malignant tumor killer worldwide. Despite the knowledge that carcinogens from tobacco smoke and the environment constitute the main causes of lung cancer, the mechanisms for lung carcinogenesis are still elusive. Cancer development and progression depend on the balance between cell survival and death signals. Common cell survival signaling pathways are activated by carcinogens as well as by inflammatory cytokines, which contribute substantially to cancer development. As a major cell survival signal, nuclear factor-kappaB (NF-kappaB) is involved in multiple steps in carcinogenesis and in cancer cell’s resistance to chemo- and radiotherapy. Recent studies with animal models and cell culture systems have established the links between NF-kappaB and lung carcinogenesis, highlighting the significance of targeting the NF-kappaB signaling pathway for lung cancer treatment and chemoprevention. In this review, we summarize progresses in understanding the NF-kappaB pathway in lung cancer development as well as in modulating NF-kappaB for lung cancer prevention and therapy.
NF-kappaB; lung cancer; signaling; prevention; therapy
NF-κB and Akt are two main cell survival pathways that attenuate the anticancer efficacy of therapeutics. Our previous studies demonstrated that the Smac mimetic compound 3 (SMC3) specifically suppresses c-IAP1 and induces TNF-α autocrine to kill cancer cells. However, SMC3 also induces a cell survival signal through NF-κB activation. In this report, we further found that SMC3 potently activates Akt, which inhibits SMC3-induced cancer cell death. Strikingly, concurrent blocking NF-κB and Akt resulted in a significantly potentiated cytotoxicity. Because heat shock protein 90 (Hsp90) plays an important role in maintaining the integrity of both the NF-κB and Akt pathways in cancer cells, we examined if suppression of Hsp90 is able to potentiate SMC3-induced cancer cell death. The results show that targeting Hsp90 does not interfere with SMC3-induced c-IAP1 degradation and TNF-α autocrine, the key processes for SMC3-induced cancer cell apoptosis. However, Hsp90 inhibitors effectively blocked SMC3-induced NF-κB activation through degradation of RIP1 and IKKβ, two key components of the NF-κB activation pathway, and reduced both the constitutive and SMC3-induced Akt activity through degradation of the Akt protein. Consistently, with the co-treatment of SMC3 and Hsp90 inhibitors, apoptosis was markedly sensitized and a synergistic cytotoxicity was observed. The results suggest that concurrent targeting c-IAP1 and Hsp90 by combination of SMC3 and Hsp90 inhibitors is an effective approach for improving the anticancer value of SMC3.
NF-κB; Akt; Smac mimetic; Hsp90; Cytotoxicity; Apoptosis
In the title compound, C15H21NO4S, both hydroxy groups on the piperidine ring are located in axial positions, whereas the tosyl group and the cyclopropane ring are in equatorial positions. An intramolecular O—H⋯O hydrogen bond occurs. In the crystal, molecules form inversion dimers via pairs of O—H⋯O hydrogen bonds, generating cyclic R
4(8) motifs, as noted previously in related diols.
The optical–optical double resonance time of flight (OODR-TOF) spectroscopy technique was employed to examine the 65 000–66 500 cm–1 region of the nitric oxide spectrum. In this region, we detected the following three electronic states: E 2Σ+ (ν = 2) (Rydberg state), B 2Π (ν = 23) (valence state), and L 2Π (ν = 4) (valence state). The rotational structure analysis of an unexpected band in the red part of the spectra revealed the presence of a new super-excited 2Σ+ Rydberg state at ~13.3 eV, which was populated through a three-photon transition from the intermediate A 2Σ+ (ν = 0) state. This super-excited state converges to the NO (a3Σ+) ionic state with electronic configuration (1σ)2(2σ)2(3σ)2(4σ)2(5σ)2(1π)3(2π)1(3sσ)1.
We determined the inhibitory effect of dietary atorvastatin, dietary celecoxib and voluntary running wheel exercise (RW) alone or in combination on the formation and growth of androgen-independent LNCaP tumors in castrated SCID mice. Male SCID mice were injected subcutaneously with androgen-dependent prostate cancer LNCaP cells. When the tumors reached a moderate size, the mice were surgically castrated and treated with atorvastatin (0.02% in the diet), celecoxib (0.05% in the diet) or RW alone or in combination for 42 days. RW or celecoxib alone had a moderate inhibitory effect on the androgen-independent growth of LNCaP tumors, but atorvastatin alone had little or no effect on tumor growth. Combinations of atorvastatin and celecoxib had a stronger inhibitory effect on the formation and growth of androgen-independent LNCaP tumors than either drug alone. A combination of RW together with atorvastatin and celecoxib had the most potent inhibitory effect on the progression of LNCaP tumors to androgen independent growth. The serum concentration of atorvastatin after two weeks of oral administration of atorvastatin was 6.1 ng/ml. The serum concentration of celecoxib after treatment with dietary celecoxib for two weeks was 1090 ng/ml. The serum concentration of atorvastatin but not that of celecoxib was substantially reduced when the two drugs were given in combination. The drug concentrations observed in our animal studies are comparable or less than those commonly found in humans treated with atorvastatin or celecoxib. Our results indicate that administration of atorvastatin and celecoxib together with voluntary exercise may be an effective strategy for the prevention of prostate cancer progression from androgen dependence to androgen independence.
prostate cancer; androgen depletion; progression; exercise
Smac mimetics are potential anticancer therapeutics selectively killing cancer cells through autocrine tumor necrosis factor (TNF)-mediated apoptosis pathway. Our recent study reveal that the Smac mimetic compound 3 (SMC3)-activated NF-κB protects cancer cells against apoptosis, thus blunting SMC3’s anticancer activity. Based on our previous observations that the nutrient flavonoid luteolin potently blocks TNF-induced NF-κB activation in cancer cells, we investigated if the combination of SMC3 and luteolin would achieve a synergistic anticancer activity. The results show that luteolin had no effect on autocrine TNF but it effectively blocked SMC3-induced nuclear factor kappa B (NF-κB) activation and expression of anti-apoptotic NF-κB targets. When SMC3 and luteolin were combined in treating cancer cells derived from lung and liver tumors, the activation of TNF-dependent apoptosis was markedly sensitized and a synergistic cytotoxic effect was achieved. In addition, the SMC3 and luteolin co-treatment had marginal effect on immortalized normal human bronchial epithelial cells. The results suggest that combination of SMC3 and luteolin is an effective approach for improving the anticancer value of SMC3, which has implications in cancer prevention and therapy.
NF-κB; Smac mimetic; luteolin; cytotoxicity; apoptosis