The Dynamic(s) of Adipose Stem Cell System, Their Survival, and Cessation under the Influence of Electromagnetic Fields.

CONTEXT: The electromagnetic field (EMF) is one of the external biophysical factors that can influence stem cells' structure and functionality. Depending on its frequency and magnetic flux density, EMF can have both a positive and negative effect on stem cell biology. AIMS: The aim of the study is to define EMF conditions that support beneficial physiological processes and those that lead to pathophysiological phenomena. Understanding the changes and processes occurring in stem cells after exposure to EMFs of different parameters can be an important factor to be applied in stem cell-based therapies and regenerative medicine. MATERIALS AND METHODS: In this study, using fluorescent microscopy and flow cytometry methods, the influence of EMF on adipose-derived stem cells proliferation, cell cycle, viability, and death were examined. EMF parameters were set in accordance with the ion cyclotron resonance (ICR) theory that influences Ca2+ and Mg2+ ions influx. Results were statistically developed using the ANOVA and effect size (Cohen's d) analyses. RESULTS: In this study, the continuous exposure of adipose-derived stem cells to EMF (ICR parameters: 76.6 Hz; 20 µT) causes a statistically significant increase in cell death through the enhancement of apoptotic, necrotic, and autophagic cell numbers. Apart from increased cell deaths after EMF exposure, increased proliferation after 24 h of EMF exposure has been also observed. CONCLUSIONS: Results presented in this study show that EMF influences stem cell dynamics resulting in a significantly increased cell death, thus altering the stem cell fate. It is important to further establish EMF conditions that support ASCs functioning and beneficial physiological processes for future regenerative medical purposes.

Involvement of PI3K Pathway in Glioma Cell Resistance to Temozolomide Treatment.

The aim of the study was to investigate the anticancer potential of LY294002 (PI3K inhibitor) and temozolomide using glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cells. Apoptosis, autophagy, necrosis, and granules in the cytoplasm were identified microscopically (fluorescence and electron microscopes). The mitochondrial membrane potential was studied by flow cytometry. The activity of caspases 3, 8, and 9 and Akt was evaluated fluorometrically, while the expression of Beclin 1, PI3K, Akt, mTOR, caspase 12, and Hsp27 was determined by immunoblotting. SiRNA was used to block Hsp27 and PI3K expression. Cell migration and localization of Hsp27 were tested with the wound healing assay and immunocytochemistry, respectively. LY294002 effectively diminished the migratory potential and increased programmed death of T98G and MOGGCCM. Autophagy was dominant in MOGGCCM, while apoptosis was dominant in T98G. LY294002 with temozolomide did not potentiate cell death but redirected autophagy toward apoptosis, which was correlated with ER stress. A similar effect was observed after blocking PI3K expression with siRNA. Transfection with Hsp27 siRNA significantly increased apoptosis related to ER stress. Our results indicate that inhibition of the PI3K/Akt/mTOR pathway sensitizes glioma cells to apoptosis upon temozolomide treatment, which was correlated with ER stress. Hsp27 increases the resistance of glioma cells to cell death upon temozolomide treatment.

Coumarins modulate the anti-glioma properties of temozolomide.

In the recent years, coumarin bioactive compounds have been identified to posess anticancer properties. Therefore, the aim of the present study was to investigate for the first time the efficacy of osthole, umbelliferone, esculin, and 4-hydroxycoumarin, alone and in combination with Temozolomide, in the elimination of deadly brain tumors, anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) cells via programmed death. Our results indicated that osthole, umbelliferone, esculin, and 4-hydroxycoumarin initiated mainly apoptosis in the T98G and MOGGCCM cells. Osthole was the most effective. It also initiated autophagy in a small percentage of the cell population. The co-incubation with Temozolomide did not increase the pro-apoptotic potential of natural compounds but decreased the level of autophagy in the T98G cells. Apoptosis was associated with reduced mitochondrial membrane potential, activation of caspase 3, inhibition of Bcl-2 expression and the presence of a Bcl-2/Beclin 1. Blocking of Bcl-2 expression resulted in promotion of apoptosis, but not autophagy, in the MOGGCCM and T98G lines. It also sensitized astrocytoma cells, but not GBM, to the combined osthole and TMZ treatment, which was correlated with a reduced level of Beclin 1 and increased expression of caspase 3. Osthole and TMZ, alone and in combination, inhibited the migratory phenotype of the GBM and AA cells. In summary, our results indicated that osthole effectively eliminated glioma cells via apoptosis, what was correlated with Bcl-2/Beclin 1 complex formation. Considering the anti-migratory effect, osthole and Temozolomide display antiglioma potential but it needs further extensive studies.

The influence of oxazaphosphorine agents on kidney function in rats.

BACKGROUND AND OBJECTIVE: The application of cytostatic oxazaphosphorines such as cyclophosphamide (CP) and ifosfamide (IF) is associated with the risk of kidney damage that, depending on the type of drug, dose and route of administration, adopts a different clinical entity and severity. The aim of our study was to assess the influence of CP and IF on the kidney histology and function in rats intraperitoneally treated with four doses of either CP or IF. MATERIALS AND METHODS: A total of 30 rats were divided into three groups (10 in each group): group 1 (control), sham treated with saline solution, group 2 (treated with 75mg/kg b.w. of CP), and group 3 (treated with 60mg/kg b.w. of IF). After the treatment rats were sacrificed, blood was collected and nephrectomy and cystectomy were performed. Qualitative and quantitative parameters (including neutrophil gelatinase-associated lipocalin-1, NGAL-1) of kidney function were assayed in urine and plasma. RESULTS: CP-treated rats were characterized by a significant polyuria, decreased urine pH and by decreased daily urinary excretion of sodium, potassium, urea and uric acid accompanied by increased NGAL-1 excretion. A significant decrease of the plasma uric acid concentration was also observed. IF-treated animals were also characterized by decreased urine pH but with normal daily urinary excretion of assessed substances (except for reduced uric acid excretion). Both CP and IF treated rats did not show any histopathological abnormalities in their kidneys. CONCLUSIONS: CP caused more advanced kidney dysfunction and some indices suggested the development of prerenal acute kidney injury. In the CP-treated group some particularly marked urinary and plasma uric acid disturbances suggested compensation of increased oxidative stress as uric acid is considered to exert also antioxidant properties.

Temozolomide and sorafenib as programmed cell death inducers of human glioma cells.

BACKGROUND: Gliomas are aggressive brain tumors with very high resistance to chemotherapy. Therefore, the aim of the present study was to investigate the effectiveness of sorafenib and Temozolomide in elimination of human glioma cells through apoptosis and autophagy. METHODS: MOGGCCM (anaplastic astrocytoma) and T98G (glioblastoma multiforme) cell lines incubated with sorafenib and/or Temozolomide were used in the experiments. Cell morphology (ER stress, apoptosis, autophagy, and necrosis) was analyzed microscopically while apoptosis and mitochondrial membrane potential were assessed with flow cytometry. Beclin1, LC3, p62, Hsp27, and Hsp72 levels were analyzed by immunoblotting. The activity of caspase 3, 8, and 9 was evaluated fluorometrically. Expression of Hsps was blocked by transfection with specific siRNA. RESULTS: In MOGGCCM cells, Temozolomide most frequently induced autophagy, which was accompanied by decreased p62 and increased beclin1 and LC3II levels. Sorafenib initiated mainly apoptosis. Additional incubation with Temozolomide, synergistically potentiated the pro-apoptotic properties of sorafenib, but it was mediated in a caspase-independent way. In T98G cells, the effect of the analyzed drugs on programmed cell death induction was different from that in MOGGCCM cells. Sorafenib induced autophagy, while Temozolomide initiated mainly apoptosis. After simultaneous drug application, apoptosis dominated, suggesting synergistic action of both drugs. Inhibition of Hsp27 and Hsp72 expression increased the sensitivity of both cell lines to ER stress and, to a lesser extent, to induction of apoptosis, but not autophagy. CONCLUSIONS: Sorafenib and Temozolomide applied in combination are potent apoptosis inducers in T98G and MOGGCCM cells. ER stress precedes the elimination. Blocking of Hsp expression has a greater impact on ER stress rather than apoptosis induction.

The effect of quercetin and imperatorin on programmed cell death induction in T98G cells in vitro.

BACKGROUND: High expression of HSP27 and HSP72 in glioma cells has been closely associated with chemoresistance and decreased sensitivity to programmed cell death induction. Therefore, it is important to devise therapies that effectively target invasive cancer cells by inducing cell death. The aim of our study was to assess the effect of quercetin and imperatorin applied separately and in combinations on the apoptosis and autophagy induction in human T98G cells cultured in vitro. METHODS: Cell death induction was analyzed by the staining method. The Western blotting technique and fluorimetric measurements of activity were used to assess the expression of marker proteins of apoptosis and autophagy. The specific siRNA transfected method was used for blocking of the expression of HSP27 and HSP72 genes. RESULTS: The experiments revealed the highest percentage of apoptotic cells after using a 50?M concentration of both compounds. Simultaneous quercetin and imperatorin administration induced apoptosis more effectively than incubation with single drugs. These results were accompanied with decreased HSP27 and HSP72 expression, and a high level of caspase-3 and caspase-9 activity. Autophagy was not observed. Additional experiments were performed on a cell line with blocked Hsp27 and Hsp72 expression and significant increase the sensitivity to apoptosis induction upon quercetin and imperatorin treatment was noticed. CONCLUSIONS: The present study indicates that quercetin and imperatorin are potent apoptosis inducers, especially when they act synergistically, which may be a promising combination useful in glioma therapy. Our results also demonstrated that blocking the HSP27 and HSP72 gene expression might serve as a therapeutic target for the human brain cancer.

Combined treatment with quercetin and imperatorin as a potent strategy for killing HeLa and Hep-2 cells.

The aim of the present study was to assess the effect of quercetin and imperatorin administered separately and in combination on apoptosis and autophagy induction in human cervical carcinoma HeLa cells and laryngeal carcinoma Hep-2 cells cultured in vitro. Conducted MTT measurements proved that quercetin and imperatorin displayed a strong antiproliferative activity manifested in markedly reduction of HeLa and Hep-2 cells viability as a result of treatment with 50 µM of each compound. Further cell staining assays revealed that concentration mentioned above generated the highest percentage of apoptotic cells especially in the case of application of both drugs for 48 h. Simultaneous quercetin and imperatorin administration induced apoptosis remarkably stronger than treatment with single drugs. Experiments at the molecular level confirmed these results accompanied with the decreased Hsp27 and Hsp72 expression and, in addition, with increased caspases activity. Autophagy was not observed and no significant changes in the expression of beclin-1 were noticed. Additionally, experiments were performed on the above-mentioned cell lines with blocked Hsp27 and Hsp72 expression. In these cells, no significant changes in the sensitivity to apoptosis induction upon quercetin and imperatorin treatment were observed. The present study has provided evidence supporting the potential of the combination of quercetin and imperatorin drugs as a novel tool to be used in anticancer therapy. Our results have also demonstrated that blocking of the Hsp27 and Hsp72 gene expression is not enough to sensitize cancer cells to programmed cell death induction in HeLa and Hep-2 cells.

Quercetin and sorafenib as a novel and effective couple in programmed cell death induction in human gliomas.

The aim of the present study was to investigate the effect of sorafenib and quercetin on the induction of apoptosis and autophagy in human anaplastic astrocytoma (MOGGCCM) and glioblastoma multiforme (T98G) cell lines. In MOGGCCM cells, sorafenib initiated mainly apoptosis, mediated by the mitochondrial pathway with mitochondrial membrane permeabilization, cytochrome c release to the cytoplasm, and activation of caspase 9 and 3. Additional incubation with quercetin potentiated the pro-apoptotic properties of sorafenib. In T98G cells, autophagy was observed most frequently after the sorafenib treatment. It was accompanied by increased beclin 1 and LC3II expression. Administration of quercetin after the sorafenib treatment resulted in an increased number of autophagic cells. After simultaneous drug application, the level of autophagy was lower in favour of apoptosis. Inhibition of heat shock proteins expression by specific small interfering RNA significantly increased the sensitivity of both the cell lines to induction of apoptosis, but not autophagy. We demonstrated for the first time that sorafenib and quercetin are very effective programmed cell death inducers in T98G and MOGGCCM cells, especially in cells with blocked expression of heat shock proteins.

Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment.

The aim of the present study was to investigate whether silencing of Hsp27 or Hsp72 expression in glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cells increases their sensitivity to programmed cell death induction upon temozolomide and/or quercetin treatment. Transfection with specific siRNA was performed for the Hsp gene silencing. As revealed by microscopic observation and flow cytometry, the inhibition of Hsp expression was correlated with severe apoptosis induction upon the drug treatment studied. No signs of autophagy were detected. This was correlated with a decreased mitochondrial membrane potential, increased level of cytochrome c in the cytoplasm, and activation of caspase 3 and caspase 9. All these results suggest that the apoptotic signal was mediated by an internal pathway. Additionally, in a large percentage of cells treated with temozolomide, with or without quercetin, granules within the ER system were found, which was accompanied by an increased level of caspase 12 expression. This might be correlated with ER stress. Quercetin and temozolomide also changed the shape of nuclei from circular to "croissant like" in both transfected cell lines. Our results indicate that blocking of Hsp27 and Hsp72 expression makes T98G cells and MOGGCCM cells extremely vulnerable to apoptosis induction upon temozolomide and quercetin treatment and that programmed cell death is initiated by an internal signal.

Apoptosis induction in human glioblastoma multiforme T98G cells upon temozolomide and quercetin treatment.

Glioblastoma multiforme is the most aggressive primary brain tumour. At the cellular and molecular levels, several mechanisms responsible for apoptosis or autophagy induction are blocked. Identification of molecular targets stimulating cells to initiate programmed cell death should be performed for therapeutic purposes. A promising solution is the combination of temozolomide and quercetin. The aim of our study was to evaluate the effect of both drugs, applied alone and in combinations, on apoptosis and autophagy induction in human glioblastoma multiforme T98G cells. Our results clearly indicate that quercetin and temozolomide induce apoptosis very significantly, having no effect on autophagy induction. At the molecular level, it was correlated with caspase 3 and 9 activation, cytochrome c release from the mitochondrium and a decrease in the mitochondrial membrane potential. Both drugs are also potent Hsp27 and Hsp72 inhibitors. This suggests that the apoptotic signal goes through an internal pathway. Increased expression of caspase 12 and the presence of several granules in the cytoplasm after temozolomide treatment with or without quercetin preceding appearance of apoptosis may suggest that apoptosis is initiated by ER stress. Additionally, it was accompanied by changes in the nuclear morphology from circular to 'croissant like'.

Cell death in HeLa cells upon imperatorin and cisplatin treatment.

There is growing evidence that commonly applied chemotherapy regimens can be improved by introducing new, specific, active and low side-effect drugs, or by combining substances to obtain the required clinical effect. The aim of the present study was to investigate the effects of imperatorin and cisplatin, applied separately or in combination, on apoptosis, necrosis and autophagy induction in the human cervical carcinoma cell line(HeLa). Imperatorin appeared to be a potent autophagy inducer, rather than a necrotic or apoptotic one. In contrast, cisplatin induced mainly apoptosis and necrosis after 6 h and 24 h, while longer incubation resulted only in necrosis induction. When HeLa cells were incubated with both drugs, autophagy appeared most frequently,although to a smaller extent than that observed after imperatorin administered alone. At the molecular level, autophagy was correlated with the presence of the cleaved form of microtubule-associated protein 1 light chain LC3 - LC3II. It was also accompanied by the inhibition of heat shock proteins Hsp27 and Hsp72 expression.Our results indicate that imperatorin alone, or in combination with cisplatin, is mainly an autopahgy inducer in HeLa cells.