nitrophenols and Neoplasm-Metastasis

Glycogen synthase kinase-3 (GSK-3) is a regulator of signaling pathways. KRas is frequently mutated in pancreatic cancers. The growth of certain pancreatic cancers is KRas-dependent and can be suppressed by GSK-3 inhibitors, documenting a link between KRas and GSK-3. To further elucidate the roles of GSK-3β in drug-resistance, we transfected KRas-dependent MIA-PaCa-2 pancreatic cells with wild-type (WT) and kinase-dead (KD) forms of GSK-3β. Transfection of MIA-PaCa-2 cells with WT-GSK-3β increased their resistance to various chemotherapeutic drugs and certain small molecule inhibitors. Transfection of cells with KD-GSK-3β often increased therapeutic sensitivity. An exception was observed with cells transfected with WT-GSK-3β and sensitivity to the BCL2/BCLXL ABT737 inhibitor. WT-GSK-3β reduced glycolytic capacity of the cells but did not affect the basal glycolysis and mitochondrial respiration. KD-GSK-3β decreased both basal glycolysis and glycolytic capacity and reduced mitochondrial respiration in MIA-PaCa-2 cells. As a comparison, the effects of GSK-3 on MCF-7 breast cancer cells, which have mutant

Topics: Adenocarcinoma; Adenylate Kinase; Antineoplastic Agents; bcl-X Protein; Berberine; Biphenyl Compounds; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Diabetes Mellitus; Dietary Supplements; Disease Progression; Doxorubicin; Female; Fluorouracil; Gemcitabine; Glycogen Synthase Kinase 3 beta; Glycolysis; Humans; Inhibitory Concentration 50; Malaria; MCF-7 Cells; Metformin; Molecular Targeted Therapy; Neoplasm Metastasis; Nitrophenols; Pancreatic Neoplasms; Piperazines; Protein Kinase Inhibitors; Signal Transduction; Sulfonamides; Thiadiazoles; Tumor Stem Cell Assay

Advanced stages of tumour and development of metastases are the two major problems in treating liver tumours such as hepatoblastoma (HB) and hepatocellular carcinoma (HCC), in paediatric patients. Modulation of apoptosis in HB cells enhances the sensitivity of these cells towards various drugs and has been discussed to enforce treatment. We analysed the effect of apoptosis modulators, BH3 mimetics, on mechanisms of dissemination such as adhesion or migration of HB and HCC cells. BH3 mimetics such as ABT-737 and obatoclax can reduce cell migration in a scratch assay as well as adhesion of HB and HCC cells to matrigel. Immunofluorescence staining of F-actin demonstrated that development of lamellipodia, which are important for migration, decreased. BH3 mimetics increase the level of activated caspases 3 and 7 in HUH6 cells. This results in the degradation of GTPase Cdc42, which can be determined by western blot analysis. A pan-caspase inhibitor can block the migration and degradation of Rho-GTPase. In summary, our study showed that BH3 mimetics not only enhance drug sensitivity but also may prevent metastasis by inhibiting HB and HCC cell motility.

Topics: Actins; Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Blotting, Western; Carcinoma, Hepatocellular; Caspase 3; Caspase 7; Caspase Inhibitors; cdc42 GTP-Binding Protein; Cell Adhesion; Cell Movement; Cytoskeleton; Enzyme Activation; Fluorescent Antibody Technique; Hepatoblastoma; Humans; Indoles; Neoplasm Metastasis; Nitrophenols; Oligopeptides; Piperazines; Proteolysis; Pseudopodia; Pyrroles; Sulfonamides

Overexpression of the antiapoptotic factor BCL-2 is a frequent feature of malignant disease and is commonly associated with poor prognosis and resistance to conventional chemotherapy. In breast cancer, however, high BCL-2 expression is associated with favorable prognosis, estrogen receptor (ER) positivity, and low tumor grade, whereas low expression is included in several molecular signatures associated with resistance to endocrine therapy. In the present study, we correlate BCL-2 expression and DNA methylation profiles in human breast cancer and in multiple cell models of acquired endocrine resistance to determine whether BCL-2 hypermethylation could provide a useful biomarker of response to cytotoxic therapy. In human disease, diminished expression of BCL-2 was associated with hypermethylation of the second exon, in a region that overlapped a CpG island and an ER-binding site. Hypermethylation of this region, which occurred in 10% of primary tumors, provided a stronger predictor of patient survival (P = 0.019) when compared with gene expression (n = 522). In multiple cell models of acquired endocrine resistance, BCL-2 expression was significantly reduced in parallel with increased DNA methylation of the exon 2 region. The reduction of BCL-2 expression in endocrine-resistant cells lowered their apoptotic threshold to antimitotic agents: nocodazole, paclitaxel, and the PLK1 inhibitor BI2536. This phenomenon could be reversed with ectopic expression of BCL-2, and rescued with the BCL-2 inhibitor ABT-737. Collectively, these data imply that BCL-2 hypermethylation provides a robust biomarker of response to current and next-generation cytotoxic agents in endocrine-resistant breast cancer, which may prove beneficial in directing therapeutic strategy for patients with nonresectable, metastatic disease.

Topics: Antimitotic Agents; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzamides; Biomarkers; Biphenyl Compounds; Breast Neoplasms; DNA Methylation; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Genes, bcl-2; Heterocyclic Compounds, 2-Ring; Humans; MCF-7 Cells; Neoplasm Metastasis; Nitrophenols; Nocodazole; Paclitaxel; Piperazines; Prognosis; Pteridines; Sulfonamides