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ABSTRACT: This study was carried out to investigate the effects of 100 and 217 Hz extremely low-frequency pulsed electromagnetic fields (ELF-PEMF) on cell proliferation, actin reorganization, and ROS generation in a human breast carcinoma cells (T47D). Cells were exposed for 24-72 h, at 100 and 217 Hz, 0.1 mT. The treatment induced a time dependent decrease in cell growth after 72 h and revealed an increase in fluorescence intensity in cytoplasm and actin aggregations around the nucleus as detected by fluorescence microscopy. The amount of actin in T47D cells increased after 48 h exposure to 100 Hz and 24 h to 217 Hz while no changes in nuclear morphology were detected. Exposing the cells to 217 Hz for 72 h caused a dramatically increase of intracellular ROS generation while with exposure to 100 Hz it remained nearly unchanged. These results suggest that exposure to ELF-PEMF (100, 217 Hz, 0.1 mT) are able inducing an increase of actin level, its migration toward nucleus but despite of these changes and dramatically increase in ROS generation the symptoms of apoptosis were not observed. Our results support the hypothesis that cell response to EMF may only be observed at certain window effects; such as frequency and intensity of EMF parameters.
Electromagnetic Biology and Medicine 06/2012; · 1.15 Impact Factor
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ABSTRACT: Microtubules are important components of the cell cytoskeleton, participating in protein localization and cell signaling. The capacity of leukemia cells to re-organize their microtubules is considered an integral part of differentiation in these cells in order to become mature granulocytes through treatment with all-trans retinoic acid (ATRA), an established drug for treating acute promyelocytic leukemia. In this study we examined γ-, α- and acetylated-α-tubulin content, their patterns of distribution in the cytoplasm, and the potency of centrosomes in re-organizing microtubules in different stages of ATRA-induced differentiation and apoptosis of the HL-60 cell line. The γ-tubulin content was dramatically increased following differentiation of HL-60 cells, and was then decreased after apoptosis. We also found that γ-tubulin had a diffuse, cytoplasmic pattern following apoptosis compared to the focal, centrosomal accumulation of γ-tubulin in differentiated cells. Differentiated cells had the ability to re-organize their microtubule network following nocodazole challenge testing, whereas undifferentiated cells did not show a similar ability. α-tubulin was more regularly organized in differentiated cells, and did not reveal any specific pattern of polymerization in apoptotic cells. Acetylated-α-tubulin generally followed the same organization patterns after differentiation, as that which occurred for α-tubulin. Our data is suggestive of a centrosomal and organized nucleation pattern of microtubules in HL-60 cells following differentiation, possibly mediated through up-regulation of γ-tubulin.
Molecular Medicine Reports 02/2012; 5(2):545-51. · 0.42 Impact Factor
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ABSTRACT: Berberine is an isoquinoline alkaloid with multiple pharmacological activities, including anti-inflammatory and anti-diarrhea effect, the induction of apoptosis and anti-cancer effect. It has been reported that berberine exerts its anti-inflammatory effect via suppressing nuclear factor-kappa B (NF-κB) expression. Survivin and inducible nitric oxide synthase (iNOS) proteins may contribute to the causal relationship between anti-inflammatory and anti-apoptotic function. To investigate the mechanism of berberine-induced apoptotic activities, the human erythro-myeloblastoid leukemia cell line (K562 cell line) was treated with different concentrations of berberine (25-100 μM). The most significant cellular growth arrest and apoptotic effects were observed in the cells treated with 75 μM of berberine for 72 h. The results indicate that survivin and iNOS protein levels were decreased in berberine-treated cells. However, decrease in the iNOS activity did not affect the cell growth and apoptosis. Moreover, the addition of NO donor, sodium nitroprusside, to culture medium decreased the cell growth in the present cell line, but it seemed that its concentration was too low to induce apoptosis. So despite its production by iNOS in untreated cells, NO does not play a significant role in carcinogenesis in this cell line. These results indicate that the apoptotic activity of berberine may be mediated through the reduction of survivin in K562 cells, but iNOS level and its activity does not play a significant role in berberine-induced apoptosis.
Medical Oncology 12/2011; 28(4):1577-83. · 2.14 Impact Factor
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ABSTRACT: Berberine is an isoquinoline alkaloid that has several pharmacological effects such as antiinflammatory, antimicrobial, apoptosis-inducing and anticancer effects. It has been illustrated that the antiinflammatory effect is mediated by suppressing the nuclear factor-kappa B (NF-κB) that activates expression of some antiinflammatory and antiapoptotic proteins including cyclooxygenase-2(COX-2), inducible nitric oxide synthase (iNOS) and survivin; therefore, berberine may induce apoptosis by reducing antiinflammatory and antiapoptotic agents, which suggest the relationship between antiinflammatory and apoptosis pathways. For further illustration of the mechanism of berberine action, the human ductal breast epithelial tumor cell line (T47D cell line) was treated with different concentrations of berberine (25-100 μM/ml). Berberine in 50 μM/ml had the most reducing effect on cell viability and inducing of apoptosis. The level of COX-2, iNOS and survivin proteins decreased in berberine-treated cells; however, treatment of the cells with aspirin and aminoguanidine (AG), COX-2 and iNOS inhibitors, respectively, showed that despite the cell growth-reducing effect of aspirin, AG did not have a significant effect on cell viability. On the other hand, with the attention to reduction in survivin protein level in berberine-treated cells, the results suggest that the apoptotic effect of berberine may be mediated by reduction in both of the COX-2 and survivin in T47D cell line, while the iNOS does not play any effective role in berberine-induced apoptosis.
Tumor Biology 11/2011; 33(1):207-14. · 1.94 Impact Factor
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ABSTRACT: Microtubules (MT) are important components of cell cytoskeleton and play key roles in cell motility mitosis and meiosis. They are also the targets of several anticancer agents which indicating their importance in maintaining cell viability. Microtubular reorganization contributing to apoptotic morphology occurs in normal and neoplastic cells undergoing apoptosis induced by cytotoxic drugs. The aim of this study was to correlate the changes in the MT with behavior of the gamma-tubulin in apoptotic cell, and to see if apoptitic MT showed biochemical characteristics of stable MT.
Apoptosis was induced in the human leukemia cells (HL-60) by treatment with 1 microM of all-trans retinoic acid over a 5-day period. The time course of changes was assessed using flow cytometry, DNA fragmentation and immunocytochemistry in cells labeled for alpha-tubulins, acetylated alpha-tubulin and gamma-tubulin.
The results indicated that gamma-tubulin content is increased after cells have gone through the apoptosis with a diffuse cytoplasmic pattern. Alpha-tubulin did not reveal any specific pattern of polymerization in apoptotic cells and acetylated alpha-tubulin content was also decreased in comparison with non-apoptotic cells.
Our results support the idea that microtubule reorganization is an important factor of the mammalian cells response to apoptosis, and the altered properties of the MT did not reflect changes in function as apoptosis progresses.
Iranian biomedical journal 11/2007; 11(4):209-14.
