Objective: identify novel and relevant aspects of Sorafenib action on liver cancer cells. We found that in rat hepatocholangiocarcinoma (LCSC-2) cells, exposure to the MEK/multikinase inhibitor sorafenib did not inhibit ERK phosphorylation nor induced appreciable cell death in the low micromolar range; instead, the drug elicited a raise of intracellular reactive oxygen species (ROS) accompanied by a severe decrease of oxygen consumption and intracellular ATP levels, all changes consistent with mitochondrial damage. Moreover, Sorafenib induced depolarization of isolated rat liver mitochondria, indicating a possible direct effect on the organelle. Microarray analysis of gene expression in sorafenib-trated cells revealed a metabolic reprogramming toward aerobic glycolysis, that likely accounts for resitance to drug toxicity in this cell line. Importantly, cytotoxicity was strongly potentiated by glucose withdrawal from the culture medium or by the glycolytic inhibitor 2-deoxy-glucose, a finding also confirmed in the highly malignant melanoma cell line B16F10. Mechanistic studies revealed that ROS are pivotal to cell killing by the Sorafenib + 2DG combination, and that a low content of intracellular oxidants is associated with resistance to the drug; instead, Thr172phosphorylation/activation of the AMP-activated protein kinase (AMPK), induced by Sorafenib, may exert protective effects, since cytotoxicity was enhanced by an AMPK specific inhibitor and prevented by the AMPK activator Metformin. Overall, this study identifies novel and relevant aspects of Sorafenib action on liver cancer cells, including mitochondrial damage, induction of ROS and a metabolic cell reprogramming towards glucose addiction, potentially exploitable in therapy.
The multikinase inhibitor Sorafenib enhances glycolysis and synergizes with glycolysis blockade for cancer cell killing.
Specimen part, Cell line
View SamplesVirus infection and over expression of protein in cytosol induce a subset of HSP70s. We named this response the Cytosolic Protein Response (CPR) and have been investigating it in the context of a parallel mechanism in the soluble cytosol with the UPR, and as a subcomponent of the larger HS response. This experiment was carried out to study the transcriptional aspect of CPR. In this analysis, we have triggered CPR by infiltrating proline analogue, L-azetidine-2-carboxylic acid (AZC) into Arabidopsis mature leaves. Since AZC trigger unfolded protein response(UPR) in ER as well as CPR, we have included tunicamycin treatment, which is a specific inducer of UPR to subtract the effect of UPR from the AZC response. Heat shocked samples were included to identify CPR as a subcomponent of larger HS response.
The cytosolic protein response as a subcomponent of the wider heat shock response in Arabidopsis.
No sample metadata fields
View SamplesLeaf rate elongation is extremely sensitive to soil water status.
Transcriptome profiling of leaf elongation zone under drought in contrasting rice cultivars.
Specimen part, Treatment
View SamplesEarly establishment of the apical-basal axis is prerequesite for correct embryonic development in Arabidopsis. The hypophysis is derived from the basal cell of the early embryo and is indispensible for root development; it gives rise to the root quiescent center and the central columella. Arabidopsis pvip1 pvip2 mutants show defects in embryonic root development and give rise to rootless seedlings.
Arabidopsis plant homeodomain finger proteins operate downstream of auxin accumulation in specifying the vasculature and primary root meristem.
No sample metadata fields
View SamplesRice deletion mutants have not been widely used in functional genomics, because the mutated genes are not tagged and therefore, difficult to identify
Detection of genomic deletions in rice using oligonucleotide microarrays.
Specimen part
View SamplesHIF-1 plays a crucial role in sustaining glioblastoma (GBM) cell growth and the maintenance of their undifferentiated phenotype. However, HIF-1 has been suggested to interplay with Wnt signaling components, thus activating a neuronal differentiation process in both GBM and normal brain. Here, we show that a -catenin/TCF1/HIF-1 complex directly controls the transcription of neuronal differentiation genes in hypoxia. Conversely, at higher oxygen levels, the increased expression of TCF4 exerts a transcriptional inhibitory function on the same genomic regions, thus counteracting differentiation. Moreover, we demonstrate the existence of a positive correlation between HIF-1, TCF1 and neuronal phenotype in GBM tumors, accompanied by the over-expression of several Wnt signaling components, finally impacting on patient prognosis. In conclusion, we unveil a mechanism by which TCF1 and HIF-1 induce a reminiscent neuronal differentiation of hypoxic GBM cells, which is hampered, in normoxia, by high levels of TCF4, thus de facto sustaining cell aggressiveness.
HIF-1α/Wnt signaling-dependent control of gene transcription regulates neuronal differentiation of glioblastoma stem cells.
Specimen part
View SamplesAlthough intensification of chemotherapy approaches considerably increased the outcome of pediatric T-cell Acute Lymphoblastic Leukemia (T-ALL) patients, a subgroup of them still experience treatment failure and relapse. In this context, we hypothesized that the Nrf2 signalling and its downstream effectors could be involved in sustain therapy resistance in T-ALL, as previously reported in other cancers. Indeed, in this study we identified the Aldo-Keto Reductase (AKR) enzymes AKR1C1-3, as over-expressed in T-ALL samples from therapy-resistant patients, demonstrating their fundamental role in the control of the response to vincristine (VCR) treatment. In particular, we evidence that the modulation of AKR1C1-3 gene expression and activity is sufficient to strongly affect the sensitivity of T-ALL cell lines and primary cells to VCR treatment, but not to daunorubicin, cytarabine or L-asparaginase. Moreover, we found a correlation between the degree of VCR response and the amount of AKR1Cs expression in patient-derived T-ALL xenografts. Interestingly, we show that daunorubicin and cytarabine are able to induce the over-activation of AKR1C enzymes, thus establishing a potential resistance loop generated by the combination of these drugs during T-ALL treatment.
AKR1C enzymes sustain therapy resistance in paediatric T-ALL.
Specimen part, Disease stage
View SamplesGlioblastoma (GBM) is the most devastating tumour of the brain, endowed with a fatal prognosis. Indeed, the complete eradication of cancer cell disseminated outside the GBM mass still remains a crucial issue. Given the reported strong association existing between Annexin 2A (ANXA2) expression and cell dissemination in many cancers, we evaluated the effects exerted by the modulation of ANXA2 levels in GBM cells and assessed its potential in predicting patient outcome. Here, we show that expression of ANXA2 positively correlates with metastatic gene signatures and demonstrates to be prognostic by itself. Indeed, we prove that ANXA2 is involved in cell migration, invasion, cytoskeletal remodeling and proliferation in GBM cells. Moreover, we were able to construct a gene signature representative of ANXA2 inhibition, which showed a significant prognostic potential in different GBM patient cohorts.
Annexin 2A sustains glioblastoma cell dissemination and proliferation.
Specimen part
View SamplesThe importance of regulatory T cells (Treg) for immune tolerance is well recognized, yet the signaling molecules influencing their suppressive activity are relatively poorly understood. We identified the cytoplasmic tyrosine phosphatase SHP-1 as a novel endogenous brake and modifier of the suppressive ability of Treg cells; consistent with this notion, loss of SHP-1 expression strongly augments the ability of Treg cells to suppress inflammation in a mouse model. Specific harmacological inhibition of SHP-1 enzymatic activity via the cancer drug sodium stibogluconate (SSG) potently augmented Treg cell suppressor activity both in vivo and ex vivo.
The protein tyrosine phosphatase SHP-1 modulates the suppressive activity of regulatory T cells.
Specimen part
View SamplesRNA-sequencing was performed to gain insight into the mechanism responsible for the mesenchymal-to-epithelial transition (MET) induced by loss of long non-coding RNA (lncRNA) DNM3OS in SKOV3 ovarian cancer cells. Following siRNA-mediated knockdown of DNM3OS or non-targeting control, RNA-sequencing was performed. This high-throughput data revealed knockdown of DNM3OS down-regulated the expression of genes and pathways known to induce EMT in ovarian cancer. Overall design: DNM3OS was knockdown in SKOV3 ovarian cancer cells and gene expression profiles were compared with controls using RNA-sequencing.
Decoding critical long non-coding RNA in ovarian cancer epithelial-to-mesenchymal transition.
Specimen part, Cell line, Subject
View Samples