All-trans retinoic acid influences viability, migration and adhesion of U251 glioblastoma cells

Glioblastoma (GBM) is one of the most aggressive and deadly forms of cancer. Literature data reveals that all-trans retinoic acid (ATRA) has anticancer effects on different types of tumor cells. However, data about the effects of ATRA on glioblastoma cells are contradictory. In this study, we examined whether ATRA treatment affects features of human glioblastoma U251 cells. To that end, the cells were treated with different concentrations of ATRA. Results obtained by MTT and the crystal violet assays imply that ATRA affected the viability of U251 glioblastoma cells in a dose-and time-dependent manner. Fluorescence staining of microtubule cytoskeleton protein a-tubulin revealed that ATRA induced changes in cell morphology. Using semi-quantitative RT-PCR we found that the expression of SOX3 and GFAP genes, as markers of neural differentiation, was not changed upon ATRA treatment. Thus, the observed changes in cell morphology after ATRA treatment are not associated with neural differentiation of U251 glioblastoma cells. The scratch-wound healing assay revealed that ATRA changed the mode of U251 cell migration from collective to single cell motility. The cell-matrix adhesion assay demonstrated that the pharmacologically relevant concentration of ATRA lowered the cell-matrix adhesion capability of U251 cells. In conclusion, our results imply that further studies are needed before ATRA could be considered for the treatment of glioblastoma

The overexpression of SOX2 affects the migration of human teratocarcinoma cell line NT2/D1

The altered expression of the SOX2 transcription factor is associated with oncogenic or tumor suppressor functions in human cancers. This factor regulates the migration and invasion of different cancer cells. In this study we investigated the effect of constitutive SOX2 overexpression on the migration and adhesion capacity of embryonal teratocarcinoma NT2/D1 cells derived from a metastasis of a human testicular germ cell tumor. We detected that increased SOX2 expression changed the speed, mode and path of cell migration, but not the adhesion ability of NT2/D1 cells. Additionally, we demonstrated that SOX2 overexpression increased the expression of the tumor suppressor protein p53 and the HDM2 oncogene. Our results contribute to the better understanding of the effect of SOX2 on the behavior of tumor cells originating from a human testicular germ cell tumor. Considering that NT2/D1 cells resemble cancer stem cells in many features, our results could contribute to the elucidation of the role of SOX2 in cancer stem cells behavior and the process of metastasis

Apigenin-7-o-glucoside versus apigenin: insight into the modes of anticandidal and cytotoxic actions

Bioactive potential of apigenin derivative apigenin-7-O-glucoside related to its antifungal activity on Candida spp. and cytotoxic effect on colon cancer cells was studied and compared with bioactive potential of apigenin. Antifungal activity was tested on 14 different isolates of Candida spp. using membrane permeability assay, measuring inhibition of reactive oxidative species and inhibition of CYP51 C. albicans enzyme. Cytotoxic potential of apigenin- 7-O-glucoside was tested on colon cancer HCT116 cells by measuring cell viability, apoptosis rate and apoptosis- and colon cancer-related gene expression. Obtained results indicated considerable antifungal activity of apigenin-7-O-glucoside towards all Candida isolates. Breakdown of C. albicans plasma membrane was achieved upon treatment with apigenin-7-O-glucoside for shorter period of time then with apigenin. Reduction of intra-and extracellular reactive oxidative species was achieved with minimum inhibitory concentrations of both compounds, suggesting that reactive oxidative species inhibition could be a mechanism of antifungal action. None of the compounds exhibited binding affinity to C. albicans CYP51 protein. Besides, apigenin-7-O-glucoside was more effective compared to apigenin in reduction of cell's viability and induction of cell death of HCT116 cells. Treatment with both compounds resulted in chromatin condensation, apoptotic bodies formation and apoptotic genes expression in HCT116 cells, but the apigenin-7-O-glucoside required a lower concentration to achieve the same effect. Compounds apigenin-7-O-glucoside and apigenin displayed prominent antifungal potential and cytotoxic effect on HCT116 cells. However, our results showed that apigenin-7-O-glucoside has more potent activity compared to apigenin in all assays that we used

Oncogenic activity of SOX1 in glioblastoma

Glioblastoma remains the most common and deadliest type of brain tumor and contains a population of self-renewing, highly tumorigenic glioma stem cells (GSCs), which contributes to tumor initiation and treatment resistance. Developmental programs participating in tissue development and homeostasis re-emerge in GSCs, supporting the development and progression of glioblastoma. SOX1 plays an important role in neural development and neural progenitor pool maintenance. Its impact on glioblastoma remains largely unknown. In this study, we have found that high levels of SOX1 observed in a subset of patients correlate with lower overall survival. At the cellular level, SOX1 expression is elevated in patient-derived GSCs and it is also higher in oncosphere culture compared to differentiation conditions in conventional glioblastoma cell lines. Moreover, genetic inhibition of SOX1 in patient-derived GSCs and conventional cell lines decreases self-renewal and proliferative capacity in vitro and tumor initiation and growth in vivo. Contrarily, SOX1 over-expression moderately promotes self-renewal and proliferation in GSCs. These functions seem to be independent of its activity as Wnt/beta-catenin signaling regulator. In summary, these results identify a functional role for SOX1 in regulating glioma cell heterogeneity and plasticity, and suggest SOX1 as a potential target in the GSC population in glioblastoma

Quercetin reduces pluripotency, migration and adhesion of human teratocarcinoma cell line NT2/D1 by inhibiting Wnt/beta-catenin signaling

Quercetin, a bioflavonoid found in plant foods, has a wide range of therapeutic effects. In order to examine the therapeutic potential of quercetin in teratocarcinoma, we used the human teratocarcinoma cell line NT2/D1 as an in vitro model. We have shown that quercetin inhibits the proliferation, adhesion and migration of NT2/D1 cells and downregulates the expression of pluripotency factors SOX2, Oct4 and Nanog. Our results further suggest that the anticancer effect of quercetin against human teratocarcinoma cells is mediated by targeting the canonical Wnt signaling pathway. Quercetin antagonized the Wnt/beta-catenin signaling pathway in NT2/D1 cells by inhibiting beta-catenin nuclear translocation and the consequent downregulation of beta-catenin-dependent transcription. These data suggest that quercetin as a potent inhibitor of Wnt signaling may be an effective therapeutic agent in cancers with aberrant activation of the Wnt pathway

Crosstalk between SOXB1 proteins and WNT/beta-catenin signaling in NT2/D1 cells

During early vertebrate embryogenesis, the expression of SOXB1 proteins is precisely regulated by a number of different mechanisms, including Wnt/beta-catenin signaling. This is essential for controlling the balance between stemness and differentiation in embryonic stem cells. In the present study, we analyzed the molecular mechanism of LiCl action in NT2/D1 cells and examined the crosstalk between SOXB1 proteins and Wnt signaling in this model system. We have shown that LiCl increases beta-catenin level, induces its translocation to the nucleus and consequently up-regulates beta-catenin/Tcf-dependent transcription in NT2/D1 cells. Our results also suggest that LiCl treatment leads to increased expression of SOX2 and SOX3 proteins in NT2/D1 cells through activation of canonical Wnt signaling. Finally, we have detected a negative feedback loop between beta-catenin and SOX2 expression in NT2/D1 cells. Since beta-catenin and SOX2 have been linked to processes of self-renewal and pluripotency, our results have implications for future research on the maintenance of stemness and lineage commitment of embryonic stem cells

SOX3 can promote the malignant behavior of glioblastoma cells

PurposeGlioblastoma is the most common and lethal adult brain tumor. Despite current therapeutic strategies, including surgery, radiation and chemotherapy, the median survival of glioblastoma patients is 15months. The development of this tumor depends on a sub-population of glioblastoma stem cells governing tumor propagation and therapy resistance. SOX3 plays a role in both normal neural development and carcinogenesis. However, little is known about its role in glioblastoma. Thus, the aim of this work was to elucidate the role of SOX3 in glioblastoma.MethodsSOX3 expression was assessed using real-time quantitative PCR (RT-qPCR), Western blotting and immunohistochemistry. MTT, immunocytochemistry and Transwell assays were used to evaluate the effects of exogenous SOX3 overexpression on the viability, proliferation, migration and invasion of glioblastoma cells, respectively. The expression of Hedgehog signaling pathway components and autophagy markers was assessed using RT-qPCR and Western blot analyses, respectively.ResultsHigher levels of SOX3 expression were detected in a subset of primary glioblastoma samples compared to those in non-tumoral brain tissues. Exogenous overexpression of this gene was found to increase the proliferation, viability, migration and invasion of glioblastoma cells. We also found that SOX3 up-regulation was accompanied by an enhanced activity of the Hedgehog signaling pathway and by suppression of autophagy in glioblastoma cells. Additionally, we found that SOX3 expression was elevated in patient-derived glioblastoma stem cells, as well as in oncospheres derived from glioblastoma cell lines, compared to their differentiated counterparts, implying that SOX3 expression is associated with the undifferentiated state of glioblastoma cells.ConclusionFrom our data we conclude that SOX3 can promote the malignant behavior of glioblastoma cells