scholarly journals CCL23 in Balancing the Act of Endoplasmic Reticulum Stress and Antitumor Immunity in Hepatocellular Carcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Dev Karan
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Antitumor Immunity ◽  
Immune Cell ◽  
Immune Checkpoint Blockade ◽  
Functional Activities ◽  
Chemotherapy Drugs ◽  
Response To Stress ◽  
Stress Influences

Endoplasmic reticulum (ER) stress is a cellular process in response to stress stimuli in protecting functional activities. However, sustained hyperactive ER stress influences tumor growth and development. Hepatocytes are enriched with ER and highly susceptible to ER perturbations and stress, which contribute to immunosuppression and the development of aggressive and drug-resistant hepatocellular carcinoma (HCC). ER stress-induced inflammation and tumor-derived chemokines influence the immune cell composition at the tumor site. Consequently, a decrease in the CCL23 chemokine in hepatic tumors is associated with poor survival of HCC patients and could be a mechanism hepatic tumor cells use to evade the immune system. This article describes the prospective role of CCL23 in alleviating ER stress and its impact on the HCC tumor microenvironment in promoting antitumor immunity. Moreover, approaches to reactivate CCL23 combined with immune checkpoint blockade or chemotherapy drugs may provide novel opportunities to target hepatocellular carcinoma.

A highly stable multifunctional aptamer for enhancing antitumor immunity against hepatocellular carcinoma by blocking dual immune checkpoints

2021 ◽  
Author(s):  
Yanlin Du ◽  
Da Zhang ◽  
Yiru Wang ◽  
Ming Wu ◽  
Cuilin Zhang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Immune Checkpoint ◽  
Antitumor Immunity ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Immune Checkpoints

A highly stable multifunctional aptamer was prepared for strengthening antitumor immunity through a dual immune checkpoint blockade of CTLA-4 and PD-L1.

scholarly journals An inducible ER–Golgi tether facilitates ceramide transport to alleviate lipotoxicity

2016 ◽  
Vol 216 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Li-Ka Liu ◽  
Vineet Choudhary ◽  
Alexandre Toulmay ◽  
William A. Prinz
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Golgi Complex ◽  
Growth Arrest ◽  
Signaling Molecules ◽  
Yeast Protein ◽  
Response To Stress ◽  
Sphingolipid Biosynthesis ◽  
Complex Sphingolipids ◽  
Close Contacts

Ceramides are key intermediates in sphingolipid biosynthesis and potent signaling molecules. However, excess ceramide is toxic, causing growth arrest and apoptosis. In this study, we identify a novel mechanism by which cells prevent the toxic accumulation of ceramides; they facilitate nonvesicular ceramide transfer from the endoplasmic reticulum (ER) to the Golgi complex, where ceramides are converted to complex sphingolipids. We find that the yeast protein Nvj2p promotes the nonvesicular transfer of ceramides from the ER to the Golgi complex. The protein is a tether that generates close contacts between these compartments and may directly transport ceramide. Nvj2p normally resides at contacts between the ER and other organelles, but during ER stress, it relocalizes to and increases ER–Golgi contacts. ER–Golgi contacts fail to form during ER stress in cells lacking Nvj2p. Our findings demonstrate that cells regulate ER–Golgi contacts in response to stress and reveal that nonvesicular ceramide transfer out of the ER prevents the buildup of toxic amounts of ceramides.

scholarly journals Target of rapamycin signaling mediates vacuolar fission caused by endoplasmic reticulum stress in Saccharomyces cerevisiae

2015 ◽  
Vol 26 (25) ◽  
pp. 4618-4630 ◽  
Author(s):  
Bobbiejane Stauffer ◽  
Ted Powers
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Intracellular Localization ◽  
Downstream Effectors ◽  
Genome Wide ◽  
Genetic Perturbations ◽  
Response To Stress ◽  
Induced Changes ◽  
Yeast Mutants

The yeast vacuole is equivalent to the mammalian lysosome and, in response to diverse physiological and environmental stimuli, undergoes alterations both in size and number. Here we demonstrate that vacuoles fragment in response to stress within the endoplasmic reticulum (ER) caused by chemical or genetic perturbations. We establish that this response does not involve known signaling pathways linked previously to ER stress but instead requires the rapamycin-sensitive TOR Complex 1 (TORC1), a master regulator of cell growth, together with its downstream effectors, Tap42/Sit4 and Sch9. To identify additional factors required for ER stress–induced vacuolar fragmentation, we conducted a high-throughput, genome-wide visual screen for yeast mutants that are refractory to ER stress–induced changes in vacuolar morphology. We identified several genes shown previously to be required for vacuolar fusion and/or fission, validating the utility of this approach. We also identified a number of new components important for fragmentation, including a set of proteins involved in assembly of the V-ATPase. Remarkably, we find that one of these, Vph2, undergoes a change in intracellular localization in response to ER stress and, moreover, in a manner that requires TORC1 activity. Together these results reveal a new role for TORC1 in the regulation of vacuolar behavior.

scholarly journals Akebia trifoliate (Thunb.) KoidzSeed Extract Inhibits the Proliferation of Human Hepatocellular Carcinoma Cell Lines via Inducing Endoplasmic Reticulum Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Wen-Li Lu ◽  
Hong-Yan Ren ◽  
Cao Liang ◽  
Yuan-Yuan Zhang ◽  
Ji Xu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Main Trend ◽  
G1 Phase ◽  
Cell Viability Assay ◽  
Cell Cycles ◽  
Viability Assay ◽  
M Phase ◽  
Stress Related Genes

Akebia Fructus has long been used for hepatocellular carcinoma (HCC) in China, while the molecular mechanism remains obscure. Our recent work found thatAkebia trifoliate (Thunb.) Koidzseed extract (ATSE) suppressed proliferation and induced endoplasmic reticulum (ER) stress in SMMC-7721. The present study aimed to throw more light on the mechanism. ER stress occurred after ATSE treatment in HepG2, HuH7, and SMMC-7721 cells, manifested as ER expansion, and SMMC-7721 was the most sensitive kind in terms of morphology. Cell viability assay showed that ATSE significantly inhibited cells proliferation. Flow cytometry analysis indicated that ATSE leads to an upward tendency of G0/G1 phase and a reduced trend of the continuous peak after G2/M phase in HepG2; ATSE promoted apoptosis in HuH7 and a notable reduction in G0/G1 phase; ATSE does not quite influence cell cycles of SMMC-7721. Western blot analysis showed an increased trend of the chosen ER stress-related proteins after different treatments but nonsignificantly; only HYOU1 and GRP78 were decreased notably by ATSE in HuH7. Affymetrix array indicated that lots of ER stress-related genes’ expressions were significantly altered, and downward is the main trend. These results suggest that ATSE have anticancer potency in HCC cells via partly inducing ER stress.

Hepatitis B virus small envelope protein promotes HCC angiogenesis via ER stress signaling to upregulate VEGFA expression

2021 ◽  
Author(s):  
Shu-Xiang Wu ◽  
Shuang-Shuang Ye ◽  
Yu-Xiang Hong ◽  
Yan Chen ◽  
Biao Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endoplasmic Reticulum ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Er Stress ◽  
Viral Protein ◽  
Unfolded Protein ◽  
B Virus ◽  
Protein Response ◽  
Hcc Cells

Hepatocellular carcinoma (HCC) is a hypervascular tumor and accumulating evidence has indicated that stimulation of angiogenesis by HBV may contribute to HCC malignancy. The small protein of hepatitis B virus surface antigen (HBsAg), SHBs, is the most abundant HBV viral protein and has a close clinical association with HCC, however, whether SHBs contributes to HCC angiogenesis remains unknown. This study reports that forced expression of SHBs in HCC cells promoted xenograft tumor growth and increased the microvessel density (MVD) within the tumors. Consistently, HBsAg was also positively correlated with MVD count in HCC patients’ specimens. The conditioned media from the SHBs-transfected HCC cells increased the capillary tube formation and migration of human umbilical vein endothelial cells (HUVECs). Intriguingly, overexpression of SHBs increased VEGFA expression at both mRNA and protein levels. A higher VEGFA expression level was also observed in the xenograft tumors transplanted with SHBs-expressing HCC cells and in HBsAg-positive HCC tumor tissues as compared to their negative controls. As expected, in the culture supernatants, the secretion of VEGFA was also significantly enhanced from HCC cells expressing SHBs, which promoted HUVECs migration and vessel formation. Furthermore, all the three unfolded protein response (UPR) sensors IRE1α, PERK and ATF6 associated with endoplasmic reticulum (ER) stress were found activated in the SHBs-expressing cells and correlated with VEGFA protein expression and secretion. Taken together, these results suggest an important role of SHBs in HCC angiogenesis and may highlight a potential target for preventive and therapeutic intervention of HBV-related HCC and its malignant progression. IMPORTANCE Chronic hepatitis B virus infection is one of the important risk factors for the development and progression of hepatocellular carcinoma (HCC). HCC is characteristic of hypervascularization even at early phases of the disease due to overexpression of angiogenic factors like vascular endothelial growth factor-A (VEGFA). However, a detailed mechanism in the HBV-induced angiogenesis remains to be established. In this study, we demonstrate for the first time that the most abundant HBV viral protein, i.e. small surface antigens (SHBs) can enhance the angiogenic capacity of HCC cells by upregulation of VEGFA expression both in vitro and in vivo . Mechanistically, SHBs induced endoplasmic reticulum (ER) stress which consequently activated unfolded protein response (UPR) signaling to increase VEGFA expression and secretion. This study suggests that SHBs plays an important pro-angiogenic role in HBV-associated HCC and may represent a potential target for anti-angiogenic therapy in the HCC.

scholarly journals Inhibition of protein phosphatase 1 stimulates noncanonical ER stress eIF2α activation to enhance fisetin-induced chemosensitivity in HDAC inhibitor-resistant hepatocellular carcinoma cells

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 918 ◽  
Author(s):  
Liu ◽  
Yu-Chun ◽  
Chang ◽  
Kuo ◽  
Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Phosphatase ◽  
Cell Apoptosis ◽  
Histone Deacetylase Inhibitors ◽  
Molecular Mechanisms ◽  
Chemotherapeutic Agents ◽  
Protein Phosphatase 1 ◽  
Hcc Cells

Hepatocellular carcinoma (HCC) is a common fatal type of malignant tumor that has highly metastatic and recurrent properties. Fisetin is a natural flavonoid found in various vegetables and fruits which exhibits anti-cancer and anti-inflammatory properties, as well as other effects. Thus, we hypothesized that fisetin can act as an adjuvant therapy in cancer or drug-resistant cancer cells, and further investigated the molecular mechanisms underlying the development of drug-resistance in HCC cells. We found that fisetin effectively inhibited the cell viability of not only parental cells but also histone deacetylase inhibitors-resistant (HDACis-R) cells and enhanced the chemosensitivity of HCC cells. Interestingly, fisetin did not induce cell apoptosis through the activation of the endoplasmic reticulum (ER) stress sensor of protein kinase R (PKR)-like endoplasmic reticulum kinase, but rather through the non-canonical pathway of the protein phosphatase 1 (PP1)-mediated suppression of eIF2α phosphorylation. Moreover, fisetin-induced cell apoptosis was reversed by treatment with PP1 activator or eIF2α siRNA in HCC cells. Based on these observations, we suggest that PP1-eIF2α pathways are significantly involved in the effect of fisetin on HCC apoptosis. Thus, fisetin may act as a novel anticancer drug and new chemotherapy adjuvant which can improve the efficacy of chemotherapeutic agents and diminish their side-effects.

scholarly journals Endoplasmic reticulum stress response in yeast and humans

2014 ◽  
Vol 34 (4) ◽  
Author(s):  
Haoxi Wu ◽  
Benjamin S. H. Ng ◽  
Guillaume Thibault
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Structures ◽  
Signal Transduction Pathway ◽  
Yeast Cells ◽  
Endoplasmic Reticulum Stress Response ◽  
Unfolded Protein ◽  
Intracellular Signal Transduction Pathway ◽  
Response To Stress ◽  
Protein Response

Stress pathways monitor intracellular systems and deploy a range of regulatory mechanisms in response to stress. One of the best-characterized pathways, the UPR (unfolded protein response), is an intracellular signal transduction pathway that monitors ER (endoplasmic reticulum) homoeostasis. Its activation is required to alleviate the effects of ER stress and is highly conserved from yeast to human. Although metazoans have three UPR outputs, yeast cells rely exclusively on the Ire1 (inositol-requiring enzyme-1) pathway, which is conserved in all Eukaryotes. In general, the UPR program activates hundreds of genes to alleviate ER stress but it can lead to apoptosis if the system fails to restore homoeostasis. In this review, we summarize the major advances in understanding the response to ER stress in Sc (Saccharomyces cerevisiae), Sp (Schizosaccharomyces pombe) and humans. The contribution of solved protein structures to a better understanding of the UPR pathway is discussed. Finally, we cover the interplay of ER stress in the development of diseases.

miR-221/222 suppression protects against endoplasmic reticulum stress-induced apoptosis via p27Kip1- and MEK/ERK-mediated cell cycle regulation

2010 ◽  
Vol 391 (7) ◽  
Author(s):  
Rongyang Dai ◽  
Juan Li ◽  
Youping Liu ◽  
Dongmei Yan ◽  
Shaokun Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Cycle Regulation ◽  
Underlying Mechanisms ◽  
Induced Apoptosis ◽  
Apoptosis Regulation ◽  
Cycle Regulation ◽  
Hcc Cells

Abstract Cancer cells are relatively resistant to endoplasmic reticulum (ER) stress-induced apoptosis. However, the underlying mechanisms remain largely unclear. We observed that the microRNAs miR-221/222 are associated with apoptosis regulation under ER stress in human hepatocellular carcinoma (HCC) cells. Induction of ER stress does not trigger significant apoptosis but obviously causes downregulation of miR-221/222 in HCC cells. In these cells, ER stress-induced apoptosis is enhanced by miR-221/222 mimics and attenuated by miR-221/222 inhibitors. miR-221/222 promoted-apoptosis under ER stress is associated with p27Kip1- and MEK/ERK-mediated cell cycle regulation. Our results suggest that suppression of miR-221/222 plays a crucial role in the protection against apoptosis induced by ER stress in HCC cells.

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