scholarly journals Peptides Targeting the Interaction Between Erb1 and Ytm1 Ribosome Assembly Factors

2021 ◽  
Vol 8 ◽  
Author(s):  
Lidia Orea-Ordóñez ◽  
Susana Masiá ◽  
Jerónimo Bravo
Keyword(s):  
Cancer Cells ◽  
Protein Interactions ◽  
Ribosome Biogenesis ◽  
Acquired Resistance ◽  
Biological Action ◽  
Pol I ◽  
Assembly Factors ◽  
Multistep Process ◽  
Cellular Partner

Ribosome biogenesis is an emerging therapeutic target. It has been proposed that cancer cells are addicted to ribosome production which is therefore considered a druggable pathway in cancer therapy. Cancer cells have been shown to be more sensitive to inhibition of the ribosome production than healthy cells. Initial attempts of inhibiting ribosome biogenesis have been focused on the inhibition of transcription by targeting RNA Pol I. Despite being a promising field of research, several limitations have been identified during the development of RNA Pol I inhibitors, like the lack of specificity or acquired resistance. Ribosome biogenesis is a multistep process and additional points of intervention, downstream the very initial stage, could be investigated. Eukaryotic ribosome maturation involves the participation of more than 200 essential assembly factors that will not be part of the final mature ribosome and frequently require protein–protein interactions to exert their biological action. Using mutagenesis, we have previously shown that alteration of the complex interface between assembly factors impairs proper ribosome maturation in yeast. As a first step toward the developing of ribosome biogenesis inhibitory tools, we have used our previously solved crystal structure of the Chaetomium thermophilum complex between the assembly factors Erb1 and Ytm1 to perform a structure-guided selection of interference peptides. The peptides have been assayed in vitro for their ability to bind their cellular partner using biophysical techniques.

scholarly journals Cytosolic localization and in vitro assembly of human de novo thymidylate synthesis complex

2020 ◽  
Author(s):  
Sharon Spizzichino ◽  
Dalila Boi ◽  
Giovanna Boumis ◽  
Roberta Lucchi ◽  
Francesca R. Liberati ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Protein Interactions ◽  
De Novo ◽  
Proximity Ligation Assay ◽  
Protein Protein Interactions ◽  
Aggregation State ◽  
Entire Complex ◽  
The Individual ◽  
Thymidylate Synthesis

ABSTRACTDe novo thymidylate synthesis is a crucial pathway for normal and cancer cells. Deoxythymidine monophosphate (dTMP) is synthesized by the combined action of three enzymes: thymidylate synthase (TYMS), serine hydroxymethyltransferase (SHMT) and dihydrofolate reductase (DHFR), targets of widely used chemotherapeutics such as antifolates and 5-fluorouracil. These proteins translocate to the nucleus after SUMOylation and are suggested to assemble in this compartment into the thymidylate synthesis complex (dTMP-SC). We report the intracellular dynamics of the complex in lung cancer cells by in situ proximity ligation assay, showing that it is also detected in the cytoplasm. We have successfully assembled the dTMP synthesis complex in vitro, employing tetrameric SHMT1 and a bifunctional chimeric enzyme comprising human TYMS and DHFR. We show that the SHMT1 tetrameric state is required for efficient complex assembly, indicating that this aggregation state is evolutionary selected in eukaryotes to optimize protein-protein interactions. Lastly, our results on the activity of the complete thymidylate cycle in vitro, provide a useful tool to develop drugs targeting the entire complex instead of the individual components.

scholarly journals Personalized drug testing in a patient with non-small-cell lung cancer using cultured cancer cells from pleural effusion

2020 ◽  
Vol 48 (9) ◽  
pp. 030006052095505
Author(s):  
Ming Wu ◽  
Guodai Hong ◽  
Yu Chen ◽  
Lina Ye ◽  
Kang Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Pleural Effusion ◽  
Small Cell Lung Cancer ◽  
Cancer Cells ◽  
Targeted Therapies ◽  
Drug Testing ◽  
Acquired Resistance ◽  
Small Cell ◽  
Small Cell Lung

Objective Patients with non-small-cell lung cancer (NSCLC) and primary or acquired resistance do not respond to targeted drugs. We explored whether cancer cells can be cultured from liquid biopsies from patients with primary resistance to tyrosine kinase inhibitors (TKIs). We aimed to predict patients’ responses to drugs according to in vitro drug testing results. Methods Cancer cell cultures were established from the pleural effusion of a patient with TKI-resistant NSCLC using a conditional reprogramming technique. Phenotypic drug sensitivity tests were performed using the Cell Counting Kit-8 assay. We tested individual drugs and compared the synergistic and inhibitory effects of drug combinations. Results The results of our in vitro sensitivity test using the combination of cisplatin and pemetrexed were correlated with the patient’s response. Conclusion This represents the first successful report of predictive testing for combination therapy in patients with epidermal growth factor receptor-mutant NSCLC and primary TKI resistance. This strategy should be applicable to both chemotherapies and targeted therapies, and it will significantly improve the clinical treatment and management of patients with NSCLC and primary or acquired resistance to targeted therapies, as well as patients lacking targetable mutations.

scholarly journals Transendothelial Migration of Melanoma Cells Involves N-Cadherin-mediated Adhesion and Activation of the β-Catenin Signaling Pathway

2005 ◽  
Vol 16 (9) ◽  
pp. 4386-4397 ◽  
Author(s):  
Jianfei Qi ◽  
Ning Chen ◽  
Junfu Wang ◽  
Chi-Hung Siu
Keyword(s):  
Endothelial Cells ◽  
Cancer Cells ◽  
Cancer Metastasis ◽  
Transendothelial Migration ◽  
Melanoma Cells ◽  
Dominant Negative ◽  
Vitro Assay ◽  
Multistep Process ◽  
Adhesive Interactions

Cancer metastasis is a multistep process involving many types of cell-cell interactions, but little is known about the adhesive interactions and signaling events during extravasation of cancer cells. Transendothelial migration of cancer cells was investigated using an in vitro assay, in which melanoma cells were seeded on top of a monolayer of endothelial cells. Attachment of melanoma cells on the endothelium induced a twofold increase in N-cadherin expression in melanoma cells and the redistribution of N-cadherin to the heterotypic contacts. Transendothelial migration was inhibited when N-cadherin expression was repressed by antisense RNA, indicating a key role played by N-cadherin. Whereas N-cadherin and β-catenin colocalized in the contact regions between melanoma cells and endothelial cells during the initial stages of attachment, β-catenin disappeared from the heterotypic contacts during transmigration of melanoma cells. Immunolocalization and immunoprecipitation studies indicate that N-cadherin became tyrosine-phosphorylated, resulting in the dissociation of β-catenin from these contact regions. Concomitantly, an increase in the nuclear level of β-catenin occurred in melanoma cells, together with a sixfold increase in β-catenin-dependent transcription. Transendothelial migration was compromised in cells expressing a dominant-negative form of β-catenin, thus supporting a regulatory role of β-catenin signaling in this process.

scholarly journals Reprogrammed mRNA translation drives resistance to therapeutic targeting of ribosome biogenesis

2019 ◽  
Author(s):  
E. P. Kusnadi ◽  
A. S. Trigos ◽  
C. Cullinane ◽  
D. L. Goode ◽  
O. Larsson ◽  
...  
Keyword(s):  
Ribosome Biogenesis ◽  
Rational Design ◽  
Molecular Mechanisms ◽  
Single Agent ◽  
Acquired Resistance ◽  
Cellular Metabolism ◽  
Mrna Translation ◽  
Pol I ◽  
Polymerase I

AbstractElevated ribosome biogenesis in oncogene-driven cancers is commonly targeted by DNA-damaging cytotoxic drugs. Our first-in-human trial of CX-5461, a novel, less genotoxic agent that specifically inhibits ribosome biogenesis via suppression of RNA Polymerase I (Pol I) transcription, revealed single agent efficacy in refractory blood cancers. Despite this clinical response, patients were not cured. In parallel, we demonstrated a marked improvement in the in vivo efficacy of CX-5461 in combination with PI3K/AKT/mTORC1 pathway inhibitors. Here we show that this improved efficacy is associated with specific suppression of translation of mRNAs encoding regulators of cellular metabolism. Importantly, acquired resistance to this co-treatment is driven by translational re-wiring that results in dysregulated cellular metabolism and induction of a cAMP-dependent pathway critical for the survival of blood cancers including lymphoma and acute myeloid leukemia. Our studies identify the molecular mechanisms underpinning the response of blood cancers to selective ribosome biogenesis inhibitors and identify metabolic vulnerabilities that will facilitate the rational design of more effective regimens for Pol I-directed therapies.

scholarly journals Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

2021 ◽  
Author(s):  
Amirhossein Tavangar ◽  
Priyatha Premanth ◽  
Bo Tan ◽  
Krishnan Venkatakrishnan
Keyword(s):  
Cell Adhesion ◽  
Cancer Cells ◽  
Cell Trapping ◽  
Si Substrates ◽  
Biological Surface ◽  
Direct Laser ◽  
Cervical Cancer Cells ◽  
Multistep Process ◽  
Cell Functionality

Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing directions. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that are repellent to cancer cells but favourable for other types of cells.

scholarly journals Monocarboxylate transporter antagonism reveals metabolic vulnerabilities of viral-driven lymphomas

2021 ◽  
Vol 118 (25) ◽  
pp. e2022495118
Author(s):  
Emmanuela N. Bonglack ◽  
Joshua E. Messinger ◽  
Jana M. Cable ◽  
James Ch’ng ◽  
K. Mark Parnell ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Acquired Resistance ◽  
Chain Complex ◽  
Asymptomatic Infection ◽  
Monocarboxylate Transporter ◽  
Barr Virus ◽  
Ebv Infection ◽  
Epstein Barr ◽  
B Lymphoid

Epstein–Barr virus (EBV) is a ubiquitous herpesvirus that typically causes asymptomatic infection but can promote B lymphoid tumors in the immune suppressed. In vitro, EBV infection of primary B cells stimulates glycolysis during immortalization into lymphoblastoid cell lines (LCLs). Lactate export during glycolysis is crucial for continued proliferation of many cancer cells—part of a phenomenon known as the “Warburg effect”— and is mediated by monocarboxylate transporters (MCTs). However, the role of MCTs has yet to be studied in EBV-associated malignancies, which display Warburg-like metabolism in vitro. Here, we show that EBV infection of B lymphocytes directly promotes temporal induction of MCT1 and MCT4 through the viral proteins EBNA2 and LMP1, respectively. Functionally, MCT1 was required for early B cell proliferation, and MCT4 up-regulation promoted acquired resistance to MCT1 antagonism in LCLs. However, dual MCT1/4 inhibition led to LCL growth arrest and lactate buildup. Metabolic profiling in LCLs revealed significantly reduced oxygen consumption rates (OCRs) and NAD+/NADH ratios, contrary to previous observations of increased OCR and unaltered NAD+/NADH ratios in MCT1/4-inhibited cancer cells. Furthermore, U-13C6–glucose labeling of MCT1/4-inhibited LCLs revealed depleted glutathione pools that correlated with elevated reactive oxygen species. Finally, we found that dual MCT1/4 inhibition also sensitized LCLs to killing by the electron transport chain complex I inhibitors phenformin and metformin. These findings were extended to viral lymphomas associated with EBV and the related gammaherpesvirus KSHV, pointing at a therapeutic approach for targeting both viral lymphomas.

scholarly journals Mechanisms behind Temsirolimus Resistance Causing Reactivated Growth and Invasive Behavior of Bladder Cancer Cells In Vitro

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 777 ◽  
Author(s):  
Eva Juengel ◽  
Iyad Natsheh ◽  
Ramin Najafi ◽  
Jochen Rutz ◽  
Igor Tsaur ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Cancer Cells ◽  
Acquired Resistance ◽  
Mtor Inhibitors ◽  
Chemotactic Activity ◽  
Invasive Behavior ◽  
Bladder Cancer Cells ◽  
Resistant Cells

Background: Although mechanistic target of rapamycin (mTOR) inhibitors, such as temsirolimus, show promise in treating bladder cancer, acquired resistance often hampers efficacy. This study evaluates mechanisms leading to resistance. Methods: Cell growth, proliferation, cell cycle phases, and cell cycle regulating proteins were compared in temsirolimus resistant (res) and sensitive (parental—par) RT112 and UMUC3 bladder cancer cells. To evaluate invasive behavior, adhesion to vascular endothelium or to immobilized extracellular matrix proteins and chemotactic activity were examined. Integrin α and β subtypes were analyzed and blocking was done to evaluate physiologic integrin relevance. Results: Growth of RT112res could no longer be restrained by temsirolimus and was even enhanced in UMUC3res, accompanied by accumulation in the S- and G2/M-phase. Proteins of the cdk-cyclin and Akt-mTOR axis increased, whereas p19, p27, p53, and p73 decreased in resistant cells treated with low-dosed temsirolimus. Chemotactic activity of RT112res/UMUC3res was elevated following temsirolimus re-exposure, along with significant integrin α2, α3, and β1 alterations. Blocking revealed a functional switch of the integrins, driving the resistant cells from being adhesive to being highly motile. Conclusion: Temsirolimus resistance is associated with reactivation of bladder cancer growth and invasive behavior. The α2, α3, and β1 integrins could be attractive treatment targets to hinder temsirolimus resistance.

Controlled synthesis of upconverting nanoparticles/CuS yolk–shell nanoparticles for in vitro synergistic photothermal and photodynamic therapy of cancer cells

2017 ◽  
Vol 5 (48) ◽  
pp. 9487-9496 ◽  
Author(s):  
Chen-Xi Huang ◽  
Hua-Jian Chen ◽  
Fei Li ◽  
Wan-Ni Wang ◽  
Dong-Dong Li ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Cancer Cells ◽  
Solution Method ◽  
Controlled Synthesis ◽  
Chemical Solution ◽  
Shell Nanoparticles ◽  
Chemical Solution Method ◽  
Photodynamic Therapy Of Cancer ◽  
Multistep Process

A chemical solution method involving multistep process has been developed to fabricate UCNPs@CuS yolk–shell nanoparticles for synergistic photothermal and photodynamic therapy of cancer cells.

scholarly journals CD147 supports paclitaxel resistance via interacting with RanBP1

Oncogene ◽  
2022 ◽  
Author(s):  
Gang Nan ◽  
Shu-Hua Zhao ◽  
Ting Wang ◽  
Dong Chao ◽  
Ruo-Fei Tian ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Protein Interactions ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Great Success ◽  
Variable Response ◽  
Paclitaxel Resistance ◽  
Paclitaxel Treatment

AbstractThough the great success of paclitaxel, the variable response of patients to the drug limits its clinical utility and the precise mechanisms underlying the variable response to paclitaxel remain largely unknown. This study aims to verify the role and the underlying mechanisms of CD147 in paclitaxel resistance. Immunostaining was used to analyze human non-small-cell lung cancer (NSCLC) and ovarian cancer tissues. RNA-sequencing was used to identify downstream effectors. Annexin V-FITC/propidium iodide and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to detect apoptosis. Co-immunoprecipitation (Co-IP), fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) were performed to determine protein interactions. Fluorescence recovery after photobleaching (FRAP) was performed to measure the speed of microtubule turnover. Xenograft tumor model was established to evaluate sensitivity of cancer cells to paclitaxel in vivo. In vitro and in vivo assays showed that silencing CD147 sensitized the cancer cells to paclitaxel treatment. CD147 protected cancer cells from paclitaxel-induced caspase-3 mediated apoptosis regardless of p53 status. Truncation analysis showed that the intracellular domain of CD147 (CD147ICD) was indispensable for CD147-regulated sensitivity to paclitaxel. Via screening the interacting proteins of CD147ICD, Ran binding protein 1 (RanBP1) was identified to interact with CD147ICD via its C-terminal tail. Furthermore, we showed that RanBP1 mediated CD147-regulated microtubule stability and dynamics as well as response to paclitaxel treatment. These results demonstrated that CD147 regulated paclitaxel response by interacting with the C-terminal tail of RanBP1 and targeting CD147 may be a promising strategy for preventing paclitaxel resistant.

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