scholarly journals Thyroid Hormone and P-Glycoprotein in Tumor Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Paul J. Davis ◽  
Sandra Incerpi ◽  
Hung-Yun Lin ◽  
Heng-Yuan Tang ◽  
Thangirala Sudha ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Cell Surface Receptor ◽  
P Glycoprotein ◽  
Surface Receptor

P-glycoprotein (P-gp; multidrug resistance pump 1, MDR1; ABCB1) is a plasma membrane efflux pump that when activated in cancer cells exports chemotherapeutic agents. Transcription of the P-gp gene (MDR1) and activity of the P-gp protein are known to be affected by thyroid hormone. A cell surface receptor for thyroid hormone on integrinαvβ3 also binds tetraiodothyroacetic acid (tetrac), a derivative of L-thyroxine (T4) that blocks nongenomic actions of T4and of 3,5,3′-triiodo-L-thyronine (T3) atαvβ3. Covalently bound to a nanoparticle, tetrac as nanotetrac acts at the integrin to increase intracellular residence time of chemotherapeutic agents such as doxorubicin and etoposide that are substrates of P-gp. This action chemosensitizes cancer cells. In this review, we examine possible molecular mechanisms for the inhibitory effect of nanotetrac on P-gp activity. Mechanisms for consideration include cancer cell acidification via action of tetrac/nanotetrac on the Na+/H+exchanger (NHE1) and hormone analogue effects on calmodulin-dependent processes and on interactions of P-gp with epidermal growth factor (EGF) and osteopontin (OPN), apparently viaαvβ3. Intracellular acidification and decreased H+efflux induced by tetrac/nanotetrac via NHE1 is the most attractive explanation for the actions on P-gp and consequent increase in cancer cell retention of chemotherapeutic agent-ligands of MDR1 protein.

scholarly journals Therapy Effects of Wogonin on Ovarian Cancer Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Jiang Ruibin ◽  
Jin Bo ◽  
Wan Danying ◽  
Zhu Chihong ◽  
Feng Jianguo ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Estrogen Receptor Alpha ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Inhibitory Effect ◽  
Ovarian Cancer Cells ◽  
Cancer Cell Growth ◽  
Antitumor Effects

Background. Wogonin is a plant monoflavonoid and has been reported to induce apoptosis of cancer cells and show inhibitory effect on cancer cell growth. However, the detailed and underlying molecular mechanisms are not elucidated. In this study, we investigated the molecular and biological effects of wogonin in human ovarian A2780 cancer cells. Materials and Methods. We determined the effects of wogonin on the changes of cell cycling and apoptotic responses of cells. Western blot analysis was used to measure the effects of wogonin on protein expressions. Results. Our results showed that treatment with wogonin inhibited the cancer cell proliferation, decreased the percentage of G0/G1 subpopulation, and reduced invasiveness of A2780 cells. Exposure to wogonin also resulted in downregulated protein levels of estrogen receptor alpha (ER-α), VEGF, Bcl-2, and Akt and increased expressions of Bax and p53. In addition, exposure to wogonin increased caspase-3 cleavage and induced apoptosis in A2780 cells. Our study further showed that MPP, a specific ER-α inhibitor, significantly enhanced antitumor effects of wogonin in A2780 cells. Conclusion. Our results suggest a potential clinical impact of wogonin on management of ovarian cancer.

scholarly journals Taxifolin Resensitizes Multidrug Resistance Cancer Cells via Uncompetitive Inhibition of P-Glycoprotein Function

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3055 ◽  
Author(s):  
Hsiu-Ju Chen ◽  
Yun-Lung Chung ◽  
Chia-Ying Li ◽  
Ying-Tzu Chang ◽  
Charles Wang ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Cancer Cells ◽  
Cell Line ◽  
Cancer Cell ◽  
Cancer Cell Line ◽  
Chemotherapeutic Agents ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Uncompetitive Inhibition ◽  
P Glycoprotein

P-glycoprotein (P-gp) effluxes lots of chemotherapeutic agents and leads to multidrug resistance (MDR) in cancer treatments. The development of P-gp inhibitors from natural products provide a potential strategy for the beneficial clinical outcomes. This study aimed to evaluate the effects of the natural flavonoid taxifolin, luteolin, (−)-gallocatechin, and (−)-catechin on human P-gp activity. The kinetic interactions and underlying mechanisms of taxifolin-mediated transporter inhibition were further investigated. The transporter inhibition ability was evaluated in human P-gp stable expression cells (ABCB1/Flp-InTM-293) by calcein-AM uptake assays. The kinetics study for P-gp inhibition was evaluated by doxorubicin and rhodamine123 efflux assays. The MDR reversal ability of taxifolin were performed by SRB assays to detect the cell viability in sensitive cancer cell line (HeLaS3), and resistant cancer cell line (KB-vin). Cell cycle analysis and ABCB1 real-time RT-PCR were used for mechanical exploration. The results demonstrated that taxifolin decreased ABCB1 expression in a concentration-dependent manner. The function of P-gp was inhibited by taxifolin through uncompetitive inhibition of rhodamine 123 and doxorubicin efflux. The combination of taxifolin significantly resensitized MDR cancer cells to chemotherapeutic agents. These results suggested that taxifolin may be considered as a potential P-gp modulator for synergistic treatment of MDR cancers.

scholarly journals A novel radiolytic rotenone derivative, rotenoisin A, displays potent anticarcinogenic activity in breast cancer cells

2021 ◽  
Author(s):  
Dong-ho Bak ◽  
Seong Hee Kang ◽  
Chul-hong Park ◽  
Byung Yeoup Chung ◽  
Hyoung-Woo Bai
Keyword(s):  
Breast Cancer ◽  
Adverse Effects ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Parent Compound ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Epidermal Keratinocytes ◽  
Functional Changes ◽  
Structural Modifications

Abstract Chemotherapy for cancer treatment has therapeutic limitations, such as drug resistance, excessive toxic effects and undesirable adverse effects. Therefore, efforts to improve the safety and efficacy of chemotherapeutic agents are essential. Ionizing radiation can improve physiological and pharmacological properties by transforming structural modifications of the drug. In this study, in order to reduce the adverse effects of rotenone and increase anticancer activity, a new radiolytic rotenone derivative called rotenoisin A was generated through radiolytic transformation. Our findings showed that rotenoisin A inhibited the proliferation of breast cancer cells and increased the rate of apoptosis, whereas it had no inhibitory effect on primary epidermal keratinocytes compared with rotenone. Moreover, rotenoisin A-induced DNA damage by increasing reactive oxygen species (ROS) accumulation. It was also confirmed not only to alter the composition ratio of mitochondrial proteins, but also to result in structural and functional changes. The anticancer effect and molecular signalling mechanisms of rotenoisin A were consistent with those of rotenone, as previously reported. Our study suggests that radiolytic transformation of highly toxic compounds may be an alternative strategy for maintaining anticancer effects and reducing the toxicity of the parent compound.

scholarly journals Desethylamiodarone antagonizes the effect of thyroid hormone at the molecular level

2001 ◽  
pp. 59-64 ◽  
Author(s):  
F Bogazzi ◽  
L Bartalena ◽  
S Brogioni ◽  
A Burelli ◽  
F Raggi ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Molecular Mechanisms ◽  
Thyroid Hormone Receptor ◽  
Molecular Level ◽  
Inhibitory Effect ◽  
Mobility Shift ◽  
Down Regulation ◽  
Nih3t3 Cells ◽  
Peripheral Tissues

OBJECTIVE: To evaluate the molecular mechanisms of the inhibitory effects of amiodarone and its active metabolite, desethylamiodarone (DEA) on thyroid hormone action. MATERIALS AND METHODS: The reporter construct ME-TRE-TK-CAT or TSHbeta-TRE-TK-CAT, containing the nucleotide sequence of the thyroid hormone response element (TRE) of either malic enzyme (ME) or TSHbeta genes, thymidine kinase (TK) and chloramphenicol acetyltransferase (CAT) was transiently transfected with RSV-TRbeta into NIH3T3 cells. Gel mobility shift assay (EMSA) was performed using labelled synthetic oligonucleotides containing the ME-TRE and in vitro translated thyroid hormone receptor (TR)beta. RESULTS: Addition of 1 micromol/l T4 or T3 to the culture medium increased the basal level of ME-TRE-TK-CAT by 4.5- and 12.5-fold respectively. Amiodarone or DEA (1 micromol/l) increased CAT activity by 1.4- and 3.4-fold respectively. Combination of DEA with T4 or T3 increased CAT activity by 9.4- and 18.9-fold respectively. These data suggested that DEA, but not amiodarone, had a synergistic effect with thyroid hormone on ME-TRE, rather than the postulated inhibitory action; we supposed that this was due to overexpression of the transfected TR into the cells. When the amount of RSV-TRbeta was reduced until it was present in a limited amount, allowing competition between thyroid hormone and the drug, addition of 1 micromol/l DEA decreased the T3-dependent expression of the reporter gene by 50%. The inhibitory effect of DEA was partially due to a reduced binding of TR to ME-TRE, as assessed by EMSA. DEA activated the TR-dependent down-regulation by the negative TSH-TRE, although at low level (35% of the down-regulation produced by T3), whereas amiodarone was ineffective. Addition of 1 micromol/l DEA to T3-containing medium reduced the T3-TR-mediated down-regulation of TSH-TRE to 55%. CONCLUSIONS: Our results demonstrate that DEA, but not amiodarone, exerts a direct, although weak, effect on genes that are regulated by thyroid hormone. High concentrations of DEA antagonize the action of T3 at the molecular level, interacting with TR and reducing its binding to TREs. This effect may contribute to the hypothyroid-like effect observed in peripheral tissues of patients receiving amiodarone treatment.

Targeted Modulation of FAK/PI3K/PDK1/AKT and FAK/p53 Pathways by Cucurbitacin B for the Antiproliferation Effect Against Human Cholangiocarcinoma Cells

2020 ◽  
Vol 48 (06) ◽  
pp. 1475-1489
Author(s):  
Sirinapha Klungsaeng ◽  
Veerapol Kukongviriyapan ◽  
Auemduan Prawan ◽  
Sarinya Kongpetch ◽  
Laddawan Senggunprai
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tyrosine Kinases ◽  
Molecular Mechanisms ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Cucurbitacin B ◽  
M Phase ◽  
Cell Cycle Disruption

Inadequate responses to traditional chemotherapeutic agents in cholangiocarcinoma (CCA) emphasize a requirement for new effective compounds for the treatment of this malignancy. This study aimed to investigate the antiproliferative property of cucurbitacin B on KKU-100 CCA cells. The determination of underlying molecular mechanisms was also carried out. The results revealed that cucurbitacin B suppressed growth and replicative ability to form colonies of CCA cells, suggesting the antiproliferative effect of this compound against the cells. Flow cytometry analysis demonstrated that the interfering effect of cucurbitacin B on the CCA cell cycle at the G2/M phase was accountable for its antiproliferation property. Accompanied with cell cycle disruption, cucurbitacin B altered the expression of proteins involved in the G2/M phase transition including downregulation of cyclin A, cyclin D1, and cdc25A, and upregulation of p21. Additional molecular studies demonstrated that cucurbitacin B suppressed the activation of focal adhesion kinase (FAK) which consequently resulted in inhibition of its kinase-dependent and kinase-independent downstream targets contributing to the regulation of cell proliferation including PI3K/PDK1/AKT and p53 proteins. In this study, the transient knockdown of FAK using siRNA was employed to ascertain the role of FAK in CCA cell proliferation. Finally, the effect of cucurbitacin B on upstream receptor tyrosine kinases regulating FAK activation was elucidated. The results showed that the inhibitory effect of cucurbitacin B on FAK activation in CCA cells is mediated via interference of EGFR and HER2 expression. Collectively, cucurbitacin B might be a promising drug for CCA treatment by targeting FAK protein.

scholarly journals A Novel 3D Model for Visualization and Tracking of Fibroblast-Guided Directional Cancer Cell Migration

Biology ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 328
Author(s):  
Yihe Zhang ◽  
Bingjie Jiang ◽  
Meng Huee Lee
Keyword(s):  
Cell Migration ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Molecular Mechanisms ◽  
Cell Mass ◽  
Physical Contact ◽  
Physical Interaction ◽  
Matrix Remodeling ◽  
Cancer Cell Migration ◽  
Cell Type

Stromal fibroblasts surrounding cancer cells are a major and important constituent of the tumor microenvironment not least because they contain cancer-associated fibroblasts, a unique fibroblastic cell type that promotes tumorigenicity through extracellular matrix remodeling and secretion of soluble factors that stimulate cell differentiation and invasion. Despite much progress made in understanding the molecular mechanisms that underpin fibroblast–tumor cross-talk, relatively little is known about the way the two cell types interact from a physical contact perspective. In this study, we report a novel three-dimensional dumbbell model that would allow the physical interaction between the fibroblasts and cancer cells to be visualized and monitored by microscopy. To achieve the effect, the fibroblasts and cancer cells in 50% Matrigel suspension were seeded as independent droplets in separation from each other. To allow for cell migration and interaction, a narrow passage of Matrigel causeway was constructed in between the droplets, effectively molding the gel into the shape of a dumbbell. Under time-lapse microscopy, we were able to visualize and image the entire process of fibroblast-guided cancer cell migration event, from initial vessel-like structure formation by the fibroblasts to their subsequent invasion across the causeway, attracting and trapping the cancer cells in the process. Upon prolonged culture, the entire population of fibroblasts eventually infiltrated across the passage and condensed into a spheroid-like cell mass, encapsulating the bulk of the cancer cell population within. Suitable for almost every cell type, our model has the potential for a wider application as it can be adapted for use in drug screening and the study of cellular factors involved in cell–cell attraction.

scholarly journals A Combination of an Antimitotic and a Bromodomain 4 Inhibitor Synergistically Inhibits the Metastatic MDA-MB-231 Breast Cancer Cell Line

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Thandi Mqoco ◽  
André Stander ◽  
Anna-Mart Engelbrecht ◽  
Anna M Joubert
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Chemotherapeutic Agents ◽  
Breast Cancer Cell Lines ◽  
Mcf 7

Current chemotherapeutic agents have many side effects and are toxic to normal cells, providing impetus to identify agents that can effectively eliminate tumorigenic cells without damaging healthy cells. The aim of this study was to examine whether combining a novel BRD4 inhibitor, ITH-47, with the antimitotic estradiol analogue, ESE-15-ol, would have a synergistic effect on inhibiting the growth of two different breast cancer cell lines in vitro. Our docking and molecular dynamics studies showed that compared to JQ1, ITH-47 showed a similar binding mode with hydrogen bonds forming between the ligand nitrogens of the pyrazole, ASN99, and water of the BRD4 protein. Data from cell growth studies revealed that the GI50 of ITH-47 and ESE-15-ol after 48 hours of exposure was determined to be 15 μM and 70 nM, respectively, in metastatic MDA-MB-231 breast cancer cells. In tumorigenic MCF-7 breast cancer cells, the GI50 of ITH-47 and ESE-15-ol was 75 μM and 60 nM, respectively, after 48 hours of exposure. Furthermore, the combination of 7.5 μM and 14 nM of ITH-47 and ESE-15-ol, respectively, resulted in 50% growth inhibition of MDA-MB-231 cells resulting in a synergistic combination index (CI) of 0.7. Flow cytometry studies revealed that, compared to the control, combination-treated MDA-MB-231 cells had significantly more cells present in the sub-G1 phase and the combination treatment induced apoptosis in the MDA-MB-231 cells. Compared to vehicle-treated cells, the combination-treated cells showed decreased levels of the BRD4, as well as c-Myc protein after 48 hours of exposure. In combination, the selective BRD4 inhibitor, ITH-47, and ESE-15-ol synergistically inhibited the growth of MDA-MB-231 breast cancer cells, but not of the MCF-7 cell line. This study provides evidence that resistance to BRD4 inhibitors may be overcome by combining inhibitors with other compounds, which may have treatment potential for hormone-independent breast cancers.

Sialylation of the Sialic Acid Binding Lectin Sialoadhesin Regulates Its Ability to Mediate Cell Adhesion

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1245-1252 ◽  
Author(s):  
Yvonne C. Barnes ◽  
Tim P. Skelton ◽  
Ivan Stamenkovic ◽  
Dennis C. Sgroi
Keyword(s):  
Sialic Acid ◽  
Inhibitory Effect ◽  
Binding Activity ◽  
Cell Surface Receptor ◽  
Common Mechanism ◽  
Specific Cell ◽  
Sialic Acid Binding ◽  
Surface Receptor ◽  
Mediate Cell

The macrophage-specific cell surface receptor sialoadhesin, which is a member of the newly recognized family of sialic acid binding lectins called siglecs, binds glycoprotein and glycolipid ligands containing a2-3–linked sialic acid on the surface of several leukocyte subsets. Recently, the sialic acid binding activity of the siglec CD22 has been demonstrated to be regulated by sialylation of the CD22 receptor molecule. In the present work, we show that desialylation of in vivo macrophage sialylconjugates enhances sialoadhesin-mediated lectin activity. Herein, we show that receptor sialylation of soluble sialoadhesin inhibits its binding to Jurkat cell ligands, and that charge-dependent repulsion alone cannot explain this inhibition. Furthermore, we show that the inhibitory effect of sialic acid is partially dependent on the presence of an intact exocyclic side chain. These results, in conjunction with previous findings, suggest that sialylation of siglecs by specific glycosyltransferases may be a common mechanism by which siglec-mediated adhesion is regulated.

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