scholarly journals The NK receptor NKp46 recognizes ecto-calreticulin on ER-stressed cells

2021 ◽  
Author(s):  
Sumit Sen Santara ◽  
Angela C. Crespo ◽  
Dian-Jang Lee ◽  
Jun Hu ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Cell Surface ◽  
Er Stress ◽  
Cancer Cells ◽  
Ectopic Expression ◽  
Immune Defense ◽  
Target Cells ◽  
Chemotherapy Drugs ◽  
Stressed Cells ◽  
Activating Receptor ◽  
Nk Receptor

Natural killer cells (NK) are a first line of immune defense to eliminate infected, transformed and stressed cells by releasing cytotoxic granules. NK activation is controlled by the balance of signals transmitted by activating and inhibitory receptors but activating receptor engagement is required to trigger cytotoxicity. The activating receptor NKp46, encoded by the NCR1 gene, is expressed by virtually all NK cells and is the most evolutionarily ancient NK receptor. NKp46 plays a major role in NK recognition of cancer cells, since NKp46 blocking antibodies potently inhibit NK killing of many cancer targets. Although a few viral, fungal and soluble host ligands have been identified, the endogenous cell-surface ligand of this important activating NK receptor is unknown. Here we show that NKp46 recognizes and is activated by the P-domain of externalized calreticulin (ecto-CRT). CRT, normally localized to the ER, translocates to the cell surface during ER stress and is a hallmark of chemotherapy-treated dying cancer cells that induce an immune response (immunogenic cell death, ICD). NKp46 caps with ecto-CRT in NK immune synapses formed with ecto-CRT-bearing target cells. ER stress, induced by ZIKV infection, ICD-causing chemotherapy drugs and some senescence activators, externalizes CRT and triggers NKp46 signaling. NKp46-mediated killing is inhibited by CRT knockout or knockdown or anti-CRT antibodies and is enhanced by ectopic expression of GPI-anchored CRT. NCR1/Ncr1-deficient human and mouse NK are impaired in killing ZIKV-infected, ER-stressed, and senescent cells and cancer cells that endogenously or ectopically express ecto-CRT. Importantly, NKp46 recognition of ecto-CRT controls the growth of B16 melanoma and RAS-driven lung cancer in mouse models and enhances tumor-infiltrating NK degranulation and cytokine secretion. Thus, ecto-CRT is a danger-associated molecular pattern (DAMP) that is an endogenous NKp46 ligand that promotes innate immune elimination of ER-stressed cells.

Membrane Derived Micorvesicles - Underappreciated Components of the Tumor Microenvironment That Modulate Tumor Growth, Vascularization and Metastasis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 473-473
Author(s):  
Marcin Wysoczynski ◽  
Fadhi Hayek ◽  
Janina Ratajczak ◽  
Anna Janowska-Wieczorek ◽  
Mariusz Z. Ratajczak
Keyword(s):  
Lung Cancer ◽  
Bone Marrow ◽  
Endothelial Cells ◽  
Tumor Microenvironment ◽  
Cell Surface ◽  
Cancer Cells ◽  
Lipid Raft ◽  
Membrane Lipid ◽  
Target Cells

Abstract Viable eukaryotic cells shed circular membrane fragments called microvesicles (MV) from the cell surface and secrete them from the endosomal compartments. These MV, which are different from apoptotic bodies, are enriched in lipids, proteins and mRNA. We postulate that MV play an important and underappreciated role in cell-cell communication by i) stimulating target cells with ligands that the MV express, ii) fusing with target cells and thus transferring various receptors to their surface, and iii) delivering mRNA, lipids and proteins. Since tumor cells secrete large quantities of MV we hypothesized that the latter are important constituents of the tumor microenvironment and their role in tumor progression merited investigation. First, we observed that human and murine lung cancer cell lines secrete more MV in response to non-apoptotic doses of hypoxia, irradiation and chemotherapy. The MV derived from human cancer cells chemoattracted bone marrow-, lymph node- and lung-derived fibroblasts and endothelial cells and activated in these stromal cells the phosphorylation of MAPKp42/44 and AKT. Furthermore, they also induced in bone marrow- and lung-derived fibroblasts expression of LIF, OSM, IL-11, VEGF and MMP-9. Moreover, conditioned media from marrow fibroblasts exposed to MV induced phosphorylation of STAT-3 proteins and chemoattracted lung cancer cells in a LIF- and OSM-dependent manner and, together with IL-11 and VEGF, activated osteoclasts and endothelial cells. Furthermore, MV from cancer cells embedded in Matrigel implants strongly stimulated angiogenesis. We also found that tumor-derived MV express tissue factor (TF) and activate platelets and as a result of this MV derived from activated platelets transfer several adhesion molecules from platelets to the tumor cell surface. This increases adhesiveness of lung cancer cells in endothelium and their metastatic spread in vivo after injection into syngeneic mice. Finally, we found that formation of MV depends on the formation of membrane lipid rafts. Thus we postulate that tumor- and platelet-derived MV are underappreciated constituents of the tumor microenvironment and play a pivotal role in tumor progression/metastasis and angiogenesis. As MV formation appears to be lipid raft-dependent, we suggest that inhibitors of membrane lipid raft formation (e.g, statins or polyene antibiotics) could decrease MV-dependent tumor spread/growth and we are currently testing this hypothesis in animal models in vivo.

scholarly journals Cell-specific cargo delivery using synthetic bacterial spores

2020 ◽  
Author(s):  
Minsuk Kong ◽  
Taylor B. Updegrove ◽  
Maira Alves Constantino ◽  
Devorah L. Gallardo ◽  
I-Lin Wu ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cancer Cells ◽  
Xenograft Model ◽  
Surface Proteins ◽  
Tumor Xenograft ◽  
Ovarian Cancer Cells ◽  
Target Cells ◽  
Mouse Tumor ◽  
Dependent Manner ◽  
Zebrafish Model

ABSTRACTSSHELs are synthetic bacterial spore-like particles wherein the spore’s cell surface is partially reconstituted around 1 µm-diameter silica beads coated with a lipid bilayer. Via a unique cysteine engineered in one of the surface proteins, the surface of SSHELs may be covalently decorated with molecules of interest. Here, we modified SSHELs with an affibody directed against HER2, a cell surface protein overexpressed in some breast and ovarian cancer cells, and loaded them with the chemotherapeutic agent doxorubicin. Drug-loaded SSHELs reduced tumor growth with lower toxicity in a mouse tumor xenograft model compared to free drug by specifically binding to HER2-positive cancer cells. We show that SSHELs bound to target cells are taken up and trafficked to acidic compartments, whereupon the cargo is released in a pH-dependent manner. Finally, we demonstrate that SHELLs can clear small tumor lesions in a complex tumor microenvironment in a zebrafish model of brain metastasis. We propose that SSHELs represent a versatile strategy for targeted drug delivery.

scholarly journals Tumour suppressor OTUD3 induces growth inhibition and apoptosis by directly deubiquitinating and stabilizing p53 in invasive breast carcinoma cells

2020 ◽  
Author(s):  
Qian Pu ◽  
Yan-Rong Lv ◽  
Ke Dong ◽  
Wen-Wen Geng ◽  
Hai-Dong Gao
Keyword(s):  
Breast Cancer ◽  
Breast Carcinoma ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Protein Modification ◽  
Critical Role ◽  
Ectopic Expression ◽  
Chemotherapy Drugs ◽  
Amino Terminal

Abstract Background P53 pathway inactivation plays an important role in the process of breast cancer tumourigenesis. Post-translational protein modification abnormalities have been confirmed to be an important mechanism underlying the inactivation of p53. Numerous deubiquitinating enzymes are aberrantly expressed in breast cancer, and a few deubiquitination enzymes are capable of deubiquitinating and stabilizing p53. Here, we report that OTUD3 is a deubiquitylase of p53 in breast carcinoma. Methods The correlation between the mRNA expression of OTUD3, TP53 and PTEN and the prognosis of BC was assessed with the Kaplan-Meier Plotter tool. OTUD3 protein expression in breast carcinoma was examined by immunohistochemistry and western blotting. The relationship among OTUD3, p53, and p21 proteins was analysed. Half-life analysis and ubiquitylation assay were performed to elucidate the molecular mechanism by which OTUD3 stabilizes p53. The interaction between OTUD3 and p53 in BC cells was verified by a co-immunoprecipitation assay and GST pulldown experiments. MTS proliferation detection, an apoptosis detection kit and colony formation asssy were used to investigate the functional effects of OTUD3 on breast cancer cells. Results OTUD3 downregulation is correlated with a poor prognosis in BC patients. OTUD3 expression is decreased in breast cancer tissues and independent of the histological grade.OTUD3 also inhibits cell proliferation and clone formation and increases the sensitivity of BC cells to apoptosis induced by chemotherapy drugs. A reduction in OTUD3 expression concomitant with decreased p53 abundance is correlated with human breast cancer progression. The ectopic expression of wild-type OTUD3, but not its catalytically inactive mutant, stabilizes and activates p53. Mechanistically, OTUD3 interacts directly with p53 through the amino-terminal OTU region. Finally, OTUD3 protects p53 from Mdm2-mediated ubiquitination and degradation, enabling the deubiquitination of p53 in BC cells. Conclusions In summary, we establish that OTUD3 is a potential therapeutic target for restoring p53 function in breast cancer cells and suggest that the OTUD3-p53 signalling axis plays a critical role in tumour suppression.

scholarly journals The Novel Methylation Biomarker SCARA5 Sensitizes Cancer Cells to DNA Damage Chemotherapy Drugs in NSCLC

2021 ◽  
Vol 11 ◽  
Author(s):  
Qi Peng ◽  
Yan Liu ◽  
Xuehua Kong ◽  
Jie Xian ◽  
Lin Ye ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Promoter Methylation ◽  
Ectopic Expression ◽  
A549 Cells ◽  
Chemotherapeutic Drugs ◽  
Chemotherapy Drugs ◽  
Gene Reporter Assay ◽  
Mechanistic Basis

BackgroundScavenger Receptor Class A Member 5 (SCARA5), also known as TESR, is expressed in various tissues and organs and participates in host defense. Recent studies have found SCARA5 to produce an anti-tumor effect for multiple tumors, although the mechanistic basis for the effect is unknown.MethodsBioinformatics, methylation-specific polymerase chain reaction (MSP), quantitative real-time PCR, and immunohistochemistry were used to assess promoter methylation and expression of SCARA5 in lung cancer tissues and cell lines. The biological effect of SCARA5 on lung cancer cells was confirmed by the CCK8 assay, colony formation assay, and flow cytometry. GSEA, Western blot, RNA sequencing, and luciferase-based gene reporter assay were used to explore the mechanistic basis for the anti-tumor effect of SCARA5. Chemosensitivity assays were used to evaluate the anti-tumor effect of SCARA5 in conjunction with chemotherapeutic drugs.ResultsWe found SCARA5 to be downregulated in lung cancer cell lines and tissues with SCARA5 levels negatively related to promoter methylation. Ectopic expression of SCARA5 suppressed proliferation of lung cancer both in vitro and in vivo through upregulation of HSPA5 expression, which inhibited FOXM1 expression resulting in G2/M arrest of the A549 cell line. SCARA5 also improved susceptibility of A549 cells to chemotherapeutic drugs that damage DNA.ConclusionSCARA5 was silenced in NSCLC due to promoter methylation and could be a potential tumor marker in NSCLC.

scholarly journals Tumor suppressor OTUD3 induces growth inhibition and apoptosis by directly deubiquitinating and stabilizing p53 in invasive breast carcinoma cells

2020 ◽  
Author(s):  
Qian Pu ◽  
Yan-rong Lv ◽  
Ke Dong ◽  
Wen-wen Geng ◽  
Hai-dong Gao
Keyword(s):  
Breast Cancer ◽  
Breast Carcinoma ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Protein Modification ◽  
Critical Role ◽  
Ectopic Expression ◽  
Chemotherapy Drugs ◽  
Amino Terminal

Abstract Background: P53 pathway inactivation plays an important role in the process of breast cancer tumorigenesis. Post-translational protein modification abnormalities have been confirmed to be an important mechanism underlying inactivation of p53. Numerous deubiquitinating enzymes are aberrantly expressed in breast cancer, and a few deubiquitination enzymes can deubiquitinate and stabilize p53. Here, we report that ovarian tumor (OTU) deubiquitinase 3 (OTUD3) is a deubiquitylase of p53 in breast carcinoma (BC).Methods: Correlations between the mRNA expression levels of OTUD3, TP53 and PTEN and the prognosis of BC were assessed with the Kaplan-Meier Plotter tool. OTUD3 protein expression in 80 pairs of specimens in our cohort was examined by immunohistochemistry and western blotting. The relationship among OTUD3, p53, and p21 proteins was analyzed. Half-life analysis and ubiquitylation assay were performed to elucidate the molecular mechanism by which OTUD3 stabilizes p53. The interaction between OTUD3 and p53 in BC cells was verified by a co-immunoprecipitation assay and GST pulldown experiments. MTS assay for proliferation detection, detection of apoptosis induced by cisplatin and colony formation assay were employed to investigate the functional effects of OTUD3 on breast cancer cells. Results: OTUD3 downregulation is correlated with a poor prognosis in BC patients. OTUD3 expression is decreased in breast cancer tissues and not associated with the histological grade. OTUD3 also inhibits cell proliferation and clone formation and increases the sensitivity of BC cells to apoptosis induced by chemotherapy drugs. Reduced OTUD3 expression accompanied by decreased p53 abundance is correlated with human breast cancer progression. Ectopic expression of wild-type OTUD3, but not its catalytically inactive mutant, stabilizes and activates p53. Mechanistically, OTUD3 interacts directly with p53 through the amino-terminal OTU region. Finally, OTUD3 protects p53 from murine double minute 2 (Mdm2)-mediated ubiquitination and degradation, enabling the deubiquitination of p53 in BC cells. Conclusions: In summary, we found that OTUD3 may be a potential therapeutic target for restoring p53 function in breast cancer cells and suggest that the OTUD3-p53 signaling axis may play a critical role in tumor suppression.

Fas Ligand Enhances Apoptosis of Human Lung Cancer Cells Cotreated with RIG-I-like Receptor Agonist and Radiation

2020 ◽  
Vol 20 (5) ◽  
pp. 372-381
Author(s):  
Yoshiaki Sato ◽  
Hironori Yoshino ◽  
Eichi Tsuruga ◽  
Ikuo Kashiwakura
Keyword(s):  
Lung Cancer ◽  
Cell Surface ◽  
Cancer Cells ◽  
Fas Ligand ◽  
Human Lung ◽  
Lung Cancer Cells ◽  
Poly I:C ◽  
Human Lung Cancer ◽  
Human Lung Cancer Cells ◽  
Induced Apoptosis

Background: Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) play key roles in the antiviral response, but recent works show that RLR activation elicits anticancer activity as well, including apoptosis. Previously, we demonstrated that the anticancer activity of the RLR agonist Poly(I:C)-HMW/LyoVec™ [Poly(I:C)-HMW] against human lung cancer cells was enhanced by cotreatment with ionizing radiation (IR). In addition, cotreatment with Poly(I:C)-HMW and IR induced apoptosis in a Fas-independent manner, and increased Fas expression on the cell surface. Objective: The current study investigated the resultant hypothesis that Fas ligand (FasL) may enhance apoptosis in lung cancer cells cotreated with Poly(I:C)-HMW+IR. Methods: FasL was added into culture medium at 24 h following cotreatment with Poly(I:C)- HMW+IR, after upregulation of cell surface Fas expression on human lung cancer cells A549 and H1299 have already been discussed. Results: FasL enhanced the apoptosis of A549 and H1299 cells treated with Poly(I:C)-HMW+IR. Similarly, IR alone - and not Poly(I:C)-HMW - resulted in the upregulation of cell surface Fas expression followed by a high response to FasL-induced apoptosis, thus suggesting that the high sensitivity of cells treated with Poly(I:C)-HMW+IR to FasL-induced apoptosis resulted from the cellular response to IR. Finally, knockdown of Fas by siRNA confirmed that the high response of treated cells to FasL-induced apoptosis is dependent on Fas expression. Conclusion: In summary, the present study indicates that upregulated Fas expression following cotreatment with Poly(I:C)-HMW and IR is responsive to FasL-induced apoptosis, and a combination of RLR agonist, IR, and FasL could be a potential promising cancer therapy.

Computational Approaches in Antibody-drug Conjugate Optimization for Targeted Cancer Therapy

2018 ◽  
Vol 18 (13) ◽  
pp. 1091-1109 ◽  
Author(s):  
Rita Melo ◽  
Agostinho Lemos ◽  
Antonio J. Preto ◽  
Jose G. Almeida ◽  
Joao D.G. Correia ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Coarse Grained ◽  
Cytotoxic Agent ◽  
Target Cells ◽  
Antibody Drug Conjugate ◽  
Drug Conjugate ◽  
Cross Correlation Analysis ◽  
Traditional Therapies ◽  
Modular Structures ◽  
Antibody Drug

Cancer has become one of the main leading causes of morbidity and mortality worldwide. One of the critical drawbacks of current cancer therapeutics has been the lack of the target-selectivity, as these drugs should have an effect exclusively on cancer cells while not perturbing healthy ones. In addition, their mechanism of action should be sufficiently fast to avoid the invasion of neighbouring healthy tissues by cancer cells. The use of conventional chemotherapeutic agents and other traditional therapies, such as surgery and radiotherapy, leads to off-target interactions with serious side effects. In this respect, recently developed target-selective Antibody-Drug Conjugates (ADCs) are more effective than traditional therapies, presumably due to their modular structures that combine many chemical properties simultaneously. In particular, ADCs are made up of three different units: a highly selective Monoclonal antibody (Mab) which is developed against a tumour-associated antigen, the payload (cytotoxic agent), and the linker. The latter should be stable in circulation while allowing the release of the cytotoxic agent in target cells. The modular nature of these drugs provides a platform to manipulate and improve selectivity and the toxicity of these molecules independently from each other. This in turn leads to generation of second- and third-generation ADCs, which have been more effective than the previous ones in terms of either selectivity or toxicity or both. Development of ADCs with improved efficacy requires knowledge at the atomic level regarding the structure and dynamics of the molecule. As such, we reviewed all the most recent computational methods used to attain all-atom description of the structure, energetics and dynamics of these systems. In particular, this includes homology modelling, molecular docking and refinement, atomistic and coarse-grained molecular dynamics simulations, principal component and cross-correlation analysis. The full characterization of the structure-activity relationship devoted to ADCs is critical for antibody-drug conjugate research and development.

Gadolinium Oxide Nanoparticles Enhance the Cytotoxicity of Chemotherapeutic Drugs by Blocking Autophagic Flux in Human Ovarian Cancer Cells

2020 ◽  
Vol 16 ◽  
Author(s):  
Zhixiong Xie ◽  
Tianyu Zhang ◽  
Cheng Zhong
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Hela Cells ◽  
Late Stage ◽  
Ovarian Cancer Cells ◽  
Oxide Nanoparticles ◽  
Autophagic Flux ◽  
Human Ovarian Cancer ◽  
Chemotherapeutic Drugs ◽  
Chemotherapy Drugs

Background: During chemotherapy, drugs can damage cancer cells’ DNA and cytomembrane structure, and then induce cell death. However, autophagy can increase the chemotherapy resistance of cancer cells, reducing the effect of chemotherapy. Objective: To block the autophagic flux in cancer cells, it is vital to enhance the anti-cancer efficacy of chemotherapy drugs; for this purpose, we test the gadolinium oxide nanoparticles (Gd2O3 NPs)’ effect on autophagy. Methods: The cytotoxicity of Gd2O3 NPs on HeLa cells was evaluated by a (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Then, monodasylcadaverine staining, immunofluorescence, immunoblot and apoptosis assay were conducted to evaluate the effect of Gd2O3 NPs on autophagy and efficacy of chemotherapy drugs in human ovarian cancer cells. Results: We found that Gd2O3 NPs, which have great potential for use as a contrast agent in magnetic resonance imaging, could block the late stage of autophagic flux in a dose-dependent manner and then cause autophagosome accumulation in HeLa cells. When co-treated with 8 μg/mL Gd2O3 NPs and 5 μg/mL cisplatin, the number of dead HeLa cells increased by about 20% compared with cisplatin alone. We observed the same phenomenon in cisplatin-resistant COC1/DDP cells. Conclusion: We conclude that Gd2O3 NPs can block the late stage of autophagic flux and enhance the cytotoxicity of chemotherapeutic drugs in human ovarian cancer cells. Thus, the nanoparticles have significant potential for use in both diagnosis and therapy of solid tumor.

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