Background

Epigenetic inactivation of tumor suppressor genes (TSG) by promoter CpG island hypermethylation is a hallmark of cancer. To assay its extent in human lymphoma, methylation of 24 TSG was analyzed in lymphoma-derived cell lines as well as in patient samples.

Methods

We screened for TSG methylation using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in 40 lymphoma-derived cell lines representing anaplastic large cell lymphoma, Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Hodgkin lymphoma and mantle cell lymphoma (MCL) as well as in 50 primary lymphoma samples. The methylation status of differentially methylated CD44 was verified by methylation-specific PCR and bisulfite sequencing. Gene expression of CD44 and its reactivation by DNA demethylation was determined by quantitative real-time PCR and on the protein level by flow cytometry. Induction of apoptosis by anti-CD44 antibody was analyzed by annexin-V/PI staining and flow cytometry.

Results

On average 8 ± 2.8 of 24 TSG were methylated per lymphoma cell line and 2.4 ± 2 of 24 TSG in primary lymphomas, whereas 0/24 TSG were methylated in tonsils and blood mononuclear cells from healthy donors. Notably, we identified that CD44 was hypermethylated and transcriptionally silenced in all BL and most FL and DLBCL cell lines, but was usually unmethylated and expressed in MCL cell lines. Concordant results were obtained from primary lymphoma material: CD44 was not methylated in MCL patients (0/11) whereas CD44 was frequently hypermethylated in BL patients (18/29). In cell lines with CD44 hypermethylation, expression was re-inducible at mRNA and protein levels by treatment with the DNA demethylating agent 5-Aza-2'-deoxycytidine, confirming epigenetic regulation of CD44. CD44 ligation assays with a monoclonal anti-CD44 antibody showed that CD44 can mediate apoptosis in CD44⁺ lymphoma cells. CD44 hypermethylated, CD44^- lymphoma cell lines were consistently resistant towards anti-CD44 induced apoptosis.

Conclusion

Our data show that CD44 is epigenetically regulated in lymphoma and undergoes de novo methylation in distinct lymphoma subtypes like BL. Thus CD44 may be a promising new epigenetic marker for diagnosis and a potential therapeutic target for the treatment of specific lymphoma subtypes.

Background

Though originally discovered in the immune system as an important mediator of inflammation, NF-κB has recently been shown to play key roles in the central nervous system, such as synaptogenesis, synaptic plasticity, and cognition. NF-κB activity is normally tightly regulated by its primary inhibitor, IκBα, through a unique autoinhibitory loop. In this study, we tested the hypothesis that the IκBα autoinhibitory loop ensures optimal levels of NF-κB activity to promote proper brain development and function. To do so, we utilized knock-in mice which possess mutations in the IκBα promoter to disrupt the autoinhibitory loop (IκBα^M/M KI mice).

Results

Here, we show that these mutations delay IκBα resynthesis and enhance NF-κB activation in neurons following acute activating stimuli. This leads to improved cognitive ability on tests of hippocampal-dependent learning and memory but no change in hippocampal synaptic plasticity. Instead, hippocampal neurons from IκBα^M/M KI mice form more excitatory and less inhibitory synapses in dissociated cultures and are hyperexcitable. This leads to increased burst firing of action potentials and the development of abnormal hypersynchronous discharges in vivo.

Conclusions

These results demonstrate that the IκBα autoinhibitory loop is critical for titrating appropriate levels of endogenous NF-κB activity to maintain proper neuronal function.

Painful reaction of rats to intraperitoneal injections of L-arginine, Nω-nitro-L-arginine, and agmatine was studied on the model of formalin-induced inflammation. All drugs exhibited a dubious effect on the patterns of nociceptive behavior depending on the phase of painful reaction. The dynamics of nitrate/nitrite content in animal blood and serum indicated the presence of NO-dependent and NO-independent components in the mechanisms of pharmacological effects of these drugs.

Summary

The marked decline in FDA-approved new drug candidates in recent years suggests the possibility that the “low-hanging fruit” has been almost entirely harvested. This might be particularly applicable to drugs acting on the central nervous system. Fortunately, there are several examples extant for the utility of multifunctional drugs, compounds, or drug mixtures that act on multiple additive or synergistic targets. However, to exploit this approach may require the willingness to consider the possibility that drug targets might be addressed by molecules of rather low specificity and moderate potency. The expectation is that single target molecules with high specificity might not have access to complex interacting neural pathways, and that moderate potency could engender fewer off-target side effects. Though novel compounds might be developed by combining the active functional groups of two or more drug molecules, the approach still lends itself to high throughput screening of large chemical libraries. Multifunctional compounds might be designed with the ability to: 1) offer both palliative and disease modifying actions, 2) act on targets that produce additive or synergistic therapeutic responses, 3) simultaneously evoke a therapeutic response at the desired target and prevent an undesired response mediated by an alternate target, 4) allow one component to promote the drugable characteristics (e.g., brain penetration) of the therapeutic component, and 5) prolong the duration of effectiveness of one compound by contributing the pharmacodynamic actions of another. The author takes the liberty to include examples of the situations just mentioned from studies in his laboratory in the following discussion.

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Summary:

To investigate the cerebral mechanisms of auditory detection of motion velocity in the human brain, neuromagnetic fields elicited by six moving sounds and one stationary sound were investigated with a whole-cortex magnetoencephalography (MEG) system. The stationary sound evoked only one clear response at a latency of 109±6 ms (first response, or M100), but the six moving sounds evoked two clear responses: an earlier response at a latency of 116±7 ms (M100) and a later response at a latency ranging from 180 to 760 ms (magnetic motion response, or MM). The latency and amplitude of the MM were inversely related to the velocity of the moving sounds (p<0.02). The magnetic source of MM was related to the velocity of the moving sounds (p<0.05). A dynamic neuromagnetic response, MM, was elicited by the moving sounds, which likely encoded the neural processing of auditory detection of motion velocity. A specific neural network that processes the motion velocity in the human brain probably includes the bilateral superior temporal cortices and the brainstem. The left posterior and lateral part of the auditory cortex may play a pivotal role in the auditory detection of motion velocity.

This study compared the morphological and physiological characteristics of elite female mountain bikers with road cyclists of different specialties and competitive level. Twenty-seven professional road cyclists and 12 mountain bikers (MTB) were involved. Road cyclists were classified as flat specialists (n = 10, FL), time trialists (n = 5, TT) and climbers (n = 12, C). From these cyclists two subgroups were obtained and compared: world class road cyclists (n = 5) and MTB (n = 5). Maximum oxygen uptake, peak power output, oxygen uptake at respiratory compensation point and power output at respiratory compensation point were determined in the laboratory. Body surface area and frontal area were also estimated. TT and FL showed higher body mass, body surface and frontal area compared with C and MTB. Absolute physiological parameters were generally higher in TT than the other groups. The same parameters normalized by body mass were similar between TT, C and MTB but higher compared to FL. No differences were found between world class road cyclists compared with top level MTB. These results confirm that a cyclist’s morphological characteristics are important determinants of female cycling performance. Female MTB have anthropometric characteristics similar to road climbers, whilst the physiological profile was not different between time trialists and climbers. This suggests that, as for male professional cyclists, top level time trialists have an overall performance advantage over all types of terrain.

It is shown that polypeptides which are immunologically related to gp52 mammary tumor virus are found in T and B peripheral blood lymphocytes in all breast cancer patients, in children with B-cell lymphosarcomas, and in B lymphocytes of some healthy donors. These proteins are not found in patients with tumors of other sites.