Role of IκBα as a negative regulator of EGFR and a molecular determinant of prognosis in glioblastoma multiforme

2028

Background: Glioblastoma multiforme is a complex disease that involves the deregulation of overlapping signaling pathways. Constitutive activation of the transcription factor nuclear factor-κB (NF-κB) has been broadly associated with various human cancers, including glioblastomas, and their therapy resistance and may be due to cross-coupling with other oncogenic pathways, such as epidermal growth factor signaling. Methods: Multidimensional analysis involving gene and transcript data for the endogenous NF-κB modulator IκBα/NFKBIA and clinical patient profiles of 482 glioblastomas/high-grade gliomas from multiple institutions in the United States and The Cancer Genome Atlas Pilot Project. Functional analyses using LN229, U87, and U118 glioblastoma cells, and human embryonic kidney 293T cells with transgene phenotypes for IκBα. IκBα promoter and coding sequence and promoter methylation analyses in a resistance model of 15 glioblastomas cell lines with in vitro and/or in vivo resistance to O6-alkylating agents. Results: We have identified a regulatory circuit between NF-κB and EGFR signaling in glioblastomas, where IκBα binds to EGFR and attenuates EGFR signaling by immobilizing its kinase domain into an inactive conformation. We found the NFKBIA gene at 14q13.2 deleted in 25% of glioblastomas and its occurrence mutually exclusive with EGFR amplification. Loss of NFKBIA associates independently with patient survival. Functional analyses uncover a bona fide tumor suppressor role for IκBα in glioblastoma cells, where it functions to constrain tumorigenic and migratory potential, and induce spontaneous cellular senescence, and apoptosis in response to treatment. IκBα expression is an independent predictor of patient prognosis in multiple glioblastoma populations. Glioblastomas with initially high IκBα expression significantly repress IκBα upon tumor recurrence, suggesting an acquired mechanism to evade its tumor-suppressive and/or chemo-sensitizing effects during tumor progression. Conclusions: IκBα is a molecular determinant of biological tumor behavior and patient survival in glioblastoma multiforme. Deletion of NFKBIA could present an alternate mechanism to activate EGFR signaling in EGFR non-amplified glioblastomas.

No significant financial relationships to disclose.

Comments on 'Significance of developmental expression of amphioxus Branchiostoma belcheri and zebrafish Danio rerio Hsd17b10 in biological and medical research'

The reported data on the developmental expression of Hsd17b10 gene in Danio rerio is crucial to the utilization of the D. rerio embryo as an animal model for human developmental disorders caused either by mutations on HSD17B10 (formerly HADH2) or by defective expression of the gene. Related diseases were summarized, and it was noticed that hyperinsulinaemic hypoglycaemia is not linked to HSD17B10. This inherited disease is actually caused by a deletion in the HADH gene on chromosome 4. Moreover, it was found by a revision of the reported phylogenetic tree that hydroxyacyl-CoA dehydrogenase II or rather hydroxysteroid (17beta) dehydrogenase 10 (HSD10) of amphioxus Branchiostoma belcheri-occupies a transition position from HSD10 orthologs of invertebrates to those of vertebrates.

JP-8 jet fuel exposure suppresses the immune response to viral infections

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1A h/day resulted in immediate secretion of two immunosuppressive agents, namely, interleukin-10 and prostaglandin E2. Thus, it was of interest to determine if jet fuel exposure might alter the immune response to infectious agents. The Hong Kong influenza model was used for these studies. Mice were exposed to 1000A mg/m(3) JP-8 (1A h/day) for 7A days before influenza viral infection. Animals were infected intra-nasally with virus and followed in terms of overall survival as well as immune responses. All surviving animals were killed 14A days after viral infection. In the present study, JP-8 exposure increased the severity of the viral infection by suppressing the anti-viral immune responses. That is, exposure of mice to JP-8 for 1A h/day for 7A days before infection resulted in decreased immune cell viability after exposure and infection, a greater than fourfold decrease in immune proliferative responses to mitogens, as well as an overall loss of CD3(+), CD4(+), and CD8(+) T cells from the lymph nodes, but not the spleens, of infected animals. These changes resulted in decreased survival of the exposed and infected mice, with only 33% of animals surviving as compared with 50% of mice infected but not jet fuel-exposed (and 100% of mice exposed only to JP-8). Thus, short-term, low-concentration JP-8 jet fuel exposures have significant suppressive effects on the immune system which can result in increased severity of viral infections.

Vulnerable plaque in a Swine model of carotid atherosclerosis

BACKGROUND AND PURPOSE

Distal embolism and acute thrombosis due to rupture of a vulnerable atherosclerotic plaque are the common mechanisms of stroke in patients with carotid disease. The purpose of this study was to develop the first animal model of vulnerable carotid atherosclerotic plaque.

MATERIALS AND METHODS

Carotid atherosclerotic models were created in 12 Yucatan minipigs by using a combination of partial ligation and high cholesterol diet. Retia mirabilia from these animals were examined histopathologically to identify distal embolism. The association of distal embolism with advanced atherosclerosis and a thin fibrous cap was analyzed by using the Fisher exact test.

RESULTS

Typical features of vulnerable plaques, including a thin fibrous cap, necrotic core, and intraplaque hemorrhage, were observed in this swine model of carotid atherosclerosis. Distal embolism was detected in retia mirabilia supplied by 7 of 10 carotid arteries with advanced atherosclerotic plaques, compared with 3 of 14 carotid arteries without advanced plaque (P < .05).

CONCLUSIONS

This swine model of carotid atherosclerosis contains the salient features of vulnerable plaques, including plaque rupture and distal embolism.

Portable stove use is associated with lower lung cancer mortality risk in lifetime smoky coal users

Domestic fuel combustion from cooking and heating, to which about 3 billion people worldwide are exposed, is associated with increased lung cancer risk. Lung cancer incidence in Xuanwei is the highest in China, and the attributable risk of lung cancer from unvented smoky coal burning is greater than 90%. To evaluate any lung cancer mortality reduction after changing from unvented stoves to portable stoves, we used lifetime smoky coal users in a retrospective cohort of all farmers born during 1917–1951 and residing in Xuanwei in 1976. Of the 42 422 enrolled farmers, 4054 lifetime smoky coal users changed to portable stoves, 4364 did not change, and 1074 died of lung cancer. Lung cancer morality associated with stove change was assessed by product-limit survival curves and multivariate Cox regression models. Both men (P<0.0001) and women (P<0.0001) who changed to portable stoves had a significantly increased probability of survival compared with those who did not change. Portable stoves were associated with decreased risk of lung cancer mortality in male participants (hazard ratio (HR)=0.62, 95% confidence interval (CI)=0.46–0.82) and female participants (HR=0.41, 95% CI=0.29–0.57). Portable stove use is associated with reduced lung cancer mortality risk, highlighting a cost-effective intervention that could substantially benefit health in developing countries.

JP-8 jet fuel exposure potentiates tumor development in two experimental model systems

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1 h/day resulted in immediate secretion of two immunosuppressive agents; namely, interleukin-10 (IL-10) and prostaglandin E2 (PGE2). Thus, it was of interest to determine if jet fuel exposure might promote tumor growth and metastasis. The syngeneic B16 tumor model was used for these studies. Animals were injected intravenously with tumor cells, and lung colonies were enumerated. Animals were also examined for metastatic spread of the tumor. Mice were either exposed to 1000 mg/m3 JP-8 (1 h/ day) for 7 days before tumor injection or were exposed to JP-8 at the time of tumor injection. All animals were killed 17 days after tumor injection. In the present study, JP8 exposure potentiated the growth and metastases of B16 tumors in an animal model. Exposure of mice to JP-8 for 1 h/day before tumor induction resulted in an approximately 8.7-fold increase in tumors, whereas those mice exposed to JP8 at the time of tumor induction had a 5.6-fold increase in tumor numbers. Thus, low concentration JP-8 jet fuel exposures have significant immune suppressive effects on the immune system that can result in increased tumor formation and metastases. We have now extended the observations to an experimental subcutaneous tumor model. JP8 exposure at the time of tumor induction in this model did not affect the growth of the tumor. However, JP8-exposed, tumor-bearing animals died at an accelerated rate as compared with air-exposed, tumor-bearing mice.

Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

Improved photoluminescence efficiency of patterned quantum dots incorporating a dots-in-the-well structure

InAs quantum dots embedded in InGaAs quantum well (DWELL: dots-in-the-well) structures grown on nanopatterned GaAs pyramids and planar GaAs(001) surface are comparatively investigated. Photoluminescence (PL) measurements demonstrate that the DWELL structure grown on the GaAs pyramids exhibits a broad quantum well PL band (full width at half-maximum ∼ 90 meV) and a higher quantum dot emission efficiency than the DWELL structure grown on the planar GaAs(001) substrate. These properties are attributed to the InGaAs quantum well with distributed thickness profile on the faceted GaAs pyramids, which introduces a tapered energy band structure and enhances carrier capture into the quantum dots.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

J/psi production in sqrt s_NN=200 GeV Cu+Cu collisions

Yields for J/psi production in Cu+Cu collisions at sqrt s_NN=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/psi production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N_part approximately 50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm(3).

Particle-species dependent modification of jet-induced correlations in Au+Au collisions at sqrt[s_{NN}]=200 GeV

Measurements in Au+Au collisions at sqrt[s_{NN}]=200 GeV of jet correlations for a trigger hadron at intermediate transverse momentum (p_{T,trig}) with associated mesons or baryons at lower p_{T,assoc} indicate strong modification of the away-side jet. The ratio of jet-associated baryons to mesons increases with centrality and p_{T,assoc}. For the most central collisions, the ratio is similar to that for inclusive measurements. This trend is incompatible with in-vacuum fragmentation but could be due to jetlike contributions from correlated soft partons, which recombine upon hadronization.

Effects of in utero JP-8 jet fuel exposure on the immune systems of pregnant and newborn mice

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. In the present study, the effects of in-utero JP-8 jet fuel exposure in mice were examined to ascertain any potential effects of jet fuel exposure on female personnel and their offspring. Exposure by the aerosol route (at 1000 mg/m3 for 1 h/day; similar to exposures incurred by flight line personnel) commencing during the first (d7 to birth) or last (d15 to birth) trimester of pregnancy was analyzed. It was observed that even 6-8 weeks after the last jet fuel exposure that the immune system of the dams (mother of newborn mice) was affected (in accordance with previous reports on normal mice). That is, thymus organ weights and viable cell numbers were decreased, and immune function was depressed. A decrease in viable male offspring was found, notably more pronounced when exposure started during the first trimester of pregnancy. Regardless of when jet fuel exposure started, all newborn mice (at 6-8 weeks after birth) reported significant immunosuppression. That is, newborn pups displayed decreased immune organ weights, decreased viable immune cell numbers and suppressed immune function. When the data were analyzed in relation to the respective mothers of the pups the data were more pronounced. Although all jet fuel-exposed pups were immunosuppressed as compared with control pups, male offspring were more affected by jet fuel exposure than female pups. Furthermore, the immune function of the newborn mice was directly correlated to the immune function of their respective mothers. That is, mothers showing the lowest immune function after JP-8 exposure gave birth to pups displaying the greatest effects of jet fuel exposure on immune function. Mothers who showed the highest levels of immune function after in-utero JP-8 exposure gave birth to pups displaying levels of immune function similar to controls animals that had the lowest levels of immune function. These data indicated that a genetic component might be involved in determining immune responses after jet fuel exposure. Overall, the data showed that in-utero JP-8 jet fuel exposure had long-term detrimental effects on newborn mice, particularly on the viability and immune competence of male offspring.

Early initiation of tacrolimus or cyclophosphamide therapy for idiopathic membranous nephropathy with severe proteinuria

BACKGROUND

Early initiation of therapy is warranted for patients with idiopathic membranous nephropathy (IMN) who have severe proteinuria. Therapy with tacrolimus (TAC) or intravenous cyclophosphamide (CYC) may be an option in treating such patients.

METHODS

This prospective cohort study included patients with IMN whose daily proteinuria was greater than 6.0 g with 3-6 months observation of nonimmunosuppressive therapy. One cohort received prednisone combined with oral TAC (target trough blood level of 4-8 ng/mL) for 24 weeks. The other cohort received prednisone combined with intravenous CYC (750 mg/m2 body surface) every 2 weeks for the first 8 weeks and then once per 4 weeks for the next 16 weeks.

RESULTS

Thirty patients met criteria for enrollment, and 25 patients completed therapy. The results of the 24-week therapeutic period were complete remission (CR) 4 patients (30.8%) on CYC and 8 patients (66.7%) on TAC; partial remission (PR) 7 patients (53.8%) on CYC and 3 patients (25%) on TAC; no response 2 patients (15.4%) on CYC and 1 patient (8.3%) on TAC. The percentages of remission (either PR or CR) by 4 and 8 weeks were significantly higher in TAC group than in CYC group (p<or=0.05). The probability of CR was significantly higher in the TAC group than in the CYC group (p=0.018, by log-rank test).

CONCLUSION

Earlier initiation of therapy with TAC or intravenous CYC (combined steroid) for 24 weeks was useful for Chinese adults with IMN in inducing remission of severe proteinuria, and quicker remission was seen in TAC therapy.