A moderate static magnetic field enhances TRAIL-induced apoptosis by the inhibition of Cdc2 and subsequent downregulation of survivin in human breast carcinoma cells

Static magnetic fields from earphones: Detailed measurements plus some open questions

Earphones (EP) are a worldwide, massively adopted product, assumed to be innocuous provided the recommendations on sound doses limits are followed. Nevertheless, sound is not the only physical stimulus that derives from EP use, since they include a built-in permanent magnet from which a static magnetic field (SMF) originates. We performed 2D maps of the SMF at several distances from 6 models of in-ear EP, showing that they produce an exposure that spans from ca. 20 mT on their surface down to tens of μT in the inner ear. The numerous reports of bioeffects elicited by SMF in that range of intensities (applied both acutely and chronically), together with the fact that there is no scientific consensus over the possible mechanisms of interaction with living tissues, suggest that caution could be recommendable. In addition, more research is warranted on the possible effects of the combination of SMF with extremely low frequency and radiofrequency fields, which has so far been scarcely studied. Overall, while several open questions about bioeffects of SMF remain to be addressed by the scientific community, we find sensible to suggest that the use of air-tube earphones is probably the more conservative, cautious choice.

Cell Behavioral Changes after the Application of Magneto-Mechanical Activation to Normal and Cancer Cells

In vitro cell exposure to nanoparticles, depending on the applied concentration, can help in the development of theranostic tools to better detect and treat human diseases. Recent studies have attempted to understand and exploit the impact of magnetic field-actuated internalized magnetic nanoparticles (MNPs) on the behavior of cancer cells. In this work, the viability rate of MNP’s-manipulated cancerous (MCF-7, MDA-MB-231) and non-cancerous (MCF-10A) cells was investigated in three different types of low-frequency magnetic fields: static, pulsed, and rotating field mode. In the non-cancerous cell line, the cell viability decreased mostly in cells with internalized MNPs and those treated with the pulsed field mode. In both cancer cell lines, the pulsed field mode was again the optimum magnetic field, which together with internalized MNPs caused a large decrease in cells’ viability (50–55% and 70% in MCF-7 and MDA-MB-231, respectively) while the static and rotating field modes maintained the viability at high levels. Finally, F-actin staining was used to observe the changes in the cytoskeleton and DAPI staining was performed to reveal the apoptotic alterations in cells’ nuclei before and after magneto-mechanical activation. Subsequently, reduced cell viability led to a loss of actin stress fibers and apoptotic nuclear changes in cancer cells subjected to MNPs triggered by a pulsed magnetic field.

A Static Magnetic Field Inhibits the Migration and Telomerase Function of Mouse Breast Cancer Cells

Static magnetic field (SMF) has a potential as a cancer therapeutic modality due to its specific inhibitory effects on the proliferation of multiple cancer cells. However, the underlying mechanism remains unclear, and just a few studies have examined the effects of SMF on metastasis, an important concern in cancer treatment. In this study, we evaluated the effects of moderate SMF (~150 mT) on the proliferation and migration of 4T1 breast cancer cells. Our results showed that SMF treatment accelerated cell proliferation but inhibited cell migration. Further, SMF treatment shortened the telomere length, decreased telomerase activity, and inhibited the expression of the cancer-specific marker telomerase reverse transcriptase (TERT), which may be related to expression upregulation of e2f1, a transcription repressor of TERT and positive regulator of the mitotic cell cycle. Our results revealed that SMF repressed both, cell migration and telomerase function. The telomerase network is responsive to SMF and may be involved in SMF-mediated cancer-specific effects; moreover, it may function as a therapeutic target in magnetic therapy of cancers.

Significance of Serum Survivin and -31G/C Gene Polymorphism in the Early Diagnosis of Breast Cancer in Egypt

BACKGROUND

Breast cancer is one of the most relevant malignancies among women. Molecular abnormalities in promotor region of survivin gene may account for overexpression of survivin and increased breast cancer risk. This study aimed to explore the potential association between survivin promotor gene -31G/C single nucleotide polymorphism (rs9904341) and its serum level alteration on one hand, and the risk of breast cancer in Egyptian patients on the other hand. It also aimed to assess the usefulness of survivin as an early noninvasive diagnostic biomarker and in breast cancer staging.

PATIENTS AND METHODS

A total of 135 patients with physically and pathologically confirmed breast cancer and 40 unrelated control subjects as well as 40 patients with benign breast mass were recruited from the early detection unit at National Cancer Institute, Cairo University. Genotyping was performed using allelic discrimination probes by real-time quantitative PCR and serum survivin by enzyme-linked immunosorbent assay.

RESULTS

The minor allele C of -31G/C survivin single nucleotide polymorphism was more frequent in breast cancer patients (19.3%) compared to the control group (7.5%). Furthermore, subjects with the GC + CC genotype were at increased risk of breast cancer compared to the GG genotype of the control group and also the benign group. Moreover, those patients exhibited higher serum levels of survivin compared to GG genotype. There was also significant elevation of serum survivin in different breast cancer stages.

CONCLUSION

Genetic variation in -31G/C of the survivin gene may contribute to the disposition of breast cancer in the Egyptian population. Serum survivin alteration played a pivotal role in the pathogenesis of breast cancer.

Shielding of the Geomagnetic Field Alters Actin Assembly and Inhibits Cell Motility in Human Neuroblastoma Cells

Accumulating evidence has shown that absence of the geomagnetic field (GMF), the so-called hypomagnetic field (HMF) environment, alters the biological functions in seemingly non-magnetosensitive cells and organisms, which indicates that the GMF could be sensed by non-iron-rich and non-photo-sensing cells. The underlying mechanisms of the HMF effects on those cells are closely related to their GMF sensation but remain poorly understood so far. Previously, we found that the HMF represses expressions of genes associated with cell migration and cytoskeleton assembly in human neuroblastoma cells (SH-SY5Y cell line). Here, we measured the HMF-induced changes on cell morphology, adhesion, motility and actin cytoskeleton in SH-SY5Y cells. The HMF inhibited cell adhesion and migration accompanied with a reduction in cellular F-actin amount. Moreover, following exposure to the HMF, the number of cell processes was reduced and cells were smaller in size and more round in shape. Furthermore, disordered kinetics of actin assembly in vitro were observed during exposure to the HMF, as evidenced by the presence of granule and meshed products. These results indicate that elimination of the GMF affects assembly of the motility-related actin cytoskeleton, and suggest that F-actin is a target of HMF exposure and probably a mediator of GMF sensation.