bims-istrec 2022-08-14 papers

bims-istrec

Biomed News

on Integrated stress response in cancer

Issue of 2022–08–14
nine papers selected by
the Vincenzo Ciminale lab, Istituto Oncologico Veneto

Endoplasmic Reticulum Stress-Related Signature Predicts Prognosis and Drug Response in Clear Cell Renal Cell Carcinoma.
The role of endoplasmic reticulum stress in the regulation of long noncoding RNAs in cancer.
Tumor-associated macrophages improve hypoxia-induced endoplasmic reticulum stress response in colorectal cancer cells by regulating TGF-β1/SOX4.
Stellettin B-Induced Oral Cancer Cell Death via Endoplasmic Reticulum Stress-Mitochondrial Apoptotic and Autophagic Signaling Pathway.
Licochalcone B induces DNA damage, cell cycle arrest, apoptosis, and enhances TRAIL sensitivity in hepatocellular carcinoma cells.
N6-methyladenosine-mediated CELF2 regulates CD44 alternative splicing affecting tumorigenesis via ERAD pathway in pancreatic cancer.
Schweinfurthin induces ICD without ER stress and caspase activation.
DNA damage and reticular stress in cytotoxicity and oncotic cell death of MCF-7 cells treated with fluopsin C.
uORF-Mediated Translational Regulation of ATF4 Serves as an Evolutionarily Conserved Mechanism Contributing to Non-Small-Cell Lung Cancer (NSCLC) and Stress Response.

Front Pharmacol. 2022 ;13 909123

Endoplasmic Reticulum Stress-Related Signature Predicts Prognosis and Drug Response in Clear Cell Renal Cell Carcinoma.

Yuke Zhang, Yancheng Song, Jiangwen Dai, Zhaoxiang Wang, Yuhao Zeng, Feng Chen, Peng Zhang.

  Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer. The maximum number of deaths associated with kidney cancer can be attributed to ccRCC. Disruption of cellular proteostasis results in endoplasmic reticulum (ER) stress, which is associated with various aspects of cancer. It is noteworthy that the role of ER stress in the progression of ccRCC remains unclear. We classified 526 ccRCC samples identified from the TCGA database into the C1 and C2 subtypes by consensus clustering of the 295 ER stress-related genes. The ccRCC samples belonging to subtype C2 were in their advanced tumor stage and grade. These samples were characterized by poor prognosis and malignancy immune microenvironment. The upregulation of the inhibitory immune checkpoint gene expression and unique drug sensitivity were also observed. The differentially expressed genes between the two clusters were explored. An 11-gene ER stress-related prognostic risk model was constructed following the LASSO regression and Cox regression analyses. In addition, a nomogram was constructed by integrating the clinical parameters and risk scores. The calibration curves, ROC curves, and DCA curves helped validate the accuracy of the prediction when both the TCGA dataset and the external E-MTAB-1980 dataset were considered. Moreover, we analyzed the differentially expressed genes common to the E-MTAB-1980 and TCGA datasets to screen out new therapeutic compounds. In summary, our study can potentially help in the comprehensive understanding of ER stress in ccRCC and serve as a reference for future studies on novel prognostic biomarkers and treatments.

Keywords:  clear cell renal cell carcinoma; drug response; endoplasmic reticulum stress; prognosis; tumor immune microenvironment

DOI:  https://doi.org/10.3389/fphar.2022.909123
J Cell Physiol. 2022 Aug 12.

The role of endoplasmic reticulum stress in the regulation of long noncoding RNAs in cancer.

Nasim Ebrahimi, Jamileh Saremi, Masoud Ghanaatian, Elnaz Yazdani, Samaneh Adelian, Sahar Samsami, Neda Moradi, Nadi Rostami Ravari, Amirhossein Ahmadi, Michael R Hamblin, Amir Reza Aref.

  Cancer cells must overcome a variety of external and internal stresses to survive and proliferate. These unfavorable conditions include the accumulation of mutations, nutrient deficiency, oxidative stress, and hypoxia. These stresses can cause aggregation of misfolded proteins inside the endoplasmic reticulum. Under these conditions, the cell undergoes endoplasmic reticulum stress (ER-stress), and consequently initiates the unfolded protein response (UPR). Activation of the UPR triggers transcription factors and regulatory factors, including long noncoding RNAs (lncRNAs), which control the gene expression profile to maintain cellular stability and hemostasis. Recent investigations have shown that cancer cells can ensure their survival under adverse conditions by the UPR affecting the expression of lncRNAs. Therefore, understanding the relationship between lncRNA expression and ER stress could open new avenues, and suggest potential therapies to treat various types of cancer.

Keywords:  ER stress; cell survival; long noncoding RNAs; signaling pathways; unfolded protein response (UPR)

DOI:  https://doi.org/10.1002/jcp.30846
Cell Signal. 2022 Aug 03. pii: S0898-6568(22)00192-9. [Epub ahead of print] 110430

Tumor-associated macrophages improve hypoxia-induced endoplasmic reticulum stress response in colorectal cancer cells by regulating TGF-β1/SOX4.

Yuqing Kang, Xuezhong Yang, Zhaoming Feng, Ranxu Lv, Junfeng Zhu.

  Hypoxia is a common feature of solid tumors that can induce endoplasmic reticulum stress (ERS). This study aimed to explore the mechanism behind tumor-associated macrophages (TAMs) improving the ERS response of colorectal cancer (CRC) under hypoxic conditions. Herein, it was demonstrated that TAMs reduce ERS by secreting TGF-β1 and activating SOX4/TMEM2 signaling in CRC cells. The expression levels of TGF-β1, SOX4, and TMEM2 in 20 pairs of tumor tissues and para-carcinoma tissues were assessed. A co-culture system of CRC cells with THP-1-derived macrophages under hypoxic conditions in vitro was investigated to determine the protective effect of TAMs on CRC cells. Moreover, to further verify the underlying mechanism, TGF-β1 and SOX4 were knocked down in the TAMs and CRC cells, respectively. The results exposed that TGF-β1, SOX4, and TMEM2 were abundantly expressed in tumor tissues. Moreover, the co-culture system revealed that macrophages stimulate TGF-β1 secretion under hypoxia, which depresses the CRC cells' ERS, further promoting cell proliferation and inhibiting apoptosis. Furthermore, increased TGF-β1 levels promoted the expression of SOX4 and TMEM2 in CRC cells. Conversely, the knockdown of SOX4 attenuated the protective effect of TAMs on TGF-β1-stimulated CRC cells. In conclusion, these results suggest that the elevated ERS induced by hypoxia in CRC cells could be relieved by TAMs via the secretion of TGF-β1. Finally, TGF-β1 suppresses undue ERS response in CRC cells by activating the SOX4-TMEM2 axis.

Keywords:  Colorectal cancer; Endoplasmic reticulum stress; TGF-β1; Tumor-associated macrophages

DOI:  https://doi.org/10.1016/j.cellsig.2022.110430
Int J Mol Sci. 2022 Aug 08. pii: 8813. [Epub ahead of print]23(15):

Stellettin B-Induced Oral Cancer Cell Death via Endoplasmic Reticulum Stress-Mitochondrial Apoptotic and Autophagic Signaling Pathway.

Tsu-Jen Kuo, Yen-Hsuan Jean, Po-Chang Shih, Shu-Yu Cheng, Hsiao-Mei Kuo, Yi-Ting Lee, Yu-Cheng Lai, Chung-Chih Tseng, Wu-Fu Chen, Zhi-Hong Wen.

  Oral squamous cell carcinoma (OSCC) affects tens of thousands of people worldwide. Despite advances in cancer treatment, the 5-year survival rate of patients with late-stage OSCC is low at 50-60%. Therefore, the development of anti-OSCC therapy is necessary. We evaluated the effects of marine-derived triterpene stellettin B in human OC2 and SCC4 cells. Stellettin B dose-dependently decreased the viability of both cell lines, with a significant reduction in OC2 cells at ≥0.1 µM at 24 and 48 h, and in SCC4 cells at ≥1 µM at 24 and 48 h. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells were significantly observed at 20 µM of stellettin B at 48 h, with the overexpression of cleaved caspase3 and cleaved poly(ADP-ribose) polymerase (PARP). Moreover, mitochondrial respiratory functions were ablated by stellettin B. Autophagy-related LC3-II/LC3-I ratio and Beclin-1 proteins were increased, whereas p62 was decreased. At 20 µM at 48 h, the expression levels of the endoplasmic reticulum (ER) stress biomarkers calnexin and BiP/GRP78 were significantly increased and mitogen-activated protein kinase (MAPK) signaling pathways were activated. Further investigation using the autophagy inhibitor 3-methyladenine (3-MA) demonstrated that it alleviated stellettin B-induced cell death and autophagy. Overall, our findings show that stellettin B induces the ER stress, mitochondrial stress, apoptosis, and autophagy, causing cell death of OSCC cells.

Keywords:  BiP/GRP78; ER stress; autophagy; mitochondrial stress; stellettin B

DOI:  https://doi.org/10.3390/ijms23158813
Chem Biol Interact. 2022 Aug 07. pii: S0009-2797(22)00281-2. [Epub ahead of print] 110076

Licochalcone B induces DNA damage, cell cycle arrest, apoptosis, and enhances TRAIL sensitivity in hepatocellular carcinoma cells.

Yun-Yun Zhang, Pan-Pan Feng, Hong-Fei Wang, Heng Zhang, Tao Liang, Xiao-Shan Hao, Feng-Ze Wang, Hong-Rong Fei.

  Hepatocellular carcinoma (HCC) is a highly fatal disease recognized as a growing global health crisis. Traditional Chinese herbal medicines have been used to treat patients with cancer for many years in China. This study investigated the effects of licochalcone B (LCB), a flavonoid compound isolated from the root of Glycyrrhiza uralensis Fisch., on cell proliferation, DNA damage and TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in HCC cells. Our results showed that LCB inhibited cell proliferation and induced DNA damage, cell cycle arrest and apoptosis. Treatment with LCB significantly inhibited the Akt/mTOR pathway and activated endoplasmic reticulum (ER) stress and mitogen-activated protein kinase (MAPK) signaling pathway. Moreover, combined treatment with LCB and TRAIL yielded evident enhancements in the viability reduction and apoptosis. LCB upregulated death receptor 4 (DR4) and death receptor 5 (DR5) protein in a concentration- and time-dependent manner. The knockdown of DR5 significantly suppressed TRAIL-induced cleavage of PARP, which was enhanced by LCB. Treatment with an extracellular-regulated kinase (ERK) inhibitor (PD98059) or c-Jun N-terminal kinase (JNK) inhibitor (SP600125) markedly reduced the LCB-induced upregulation of DR5 expression and attenuated LCB-mediated TRAIL sensitization. In summary, LCB exhibits cytotoxic activity through modulation of the Akt/mTOR, ER stress and MAPK pathways in HCC cells and effectively enhances TRAIL sensitivity through the upregulation of DR5 expression in ERK- and JNK-dependent manner. Combination therapy with LCB and TRAIL may be an alternative treatment strategy for HCC.

Keywords:  Apoptosis; DR5; ERK; JNK; Licochalcone B; TRAIL

DOI:  https://doi.org/10.1016/j.cbi.2022.110076
Cell Biosci. 2022 Aug 08. 12(1): 125

N6-methyladenosine-mediated CELF2 regulates CD44 alternative splicing affecting tumorigenesis via ERAD pathway in pancreatic cancer.

Shihui Lai, Yan Wang, Ting Li, Yihong Dong, Yihao Lin, Liang Wang, Shangeng Weng, Xiang Zhang, Chengjie Lin.

   BACKGROUND: Alternative splicing (AS) of genes has been found to affect gene stability, and its abnormal regulation can lead to tumorigenesis. CELF2 is a vital splicing factor to participate in mRNA alternative splicing. Its downregulation has been confirmed to promote the occurrence and development of pancreatic cancer (PC). However, the regulatory role and mechanisms in PC has not been elucidated.
RESULTS: CELF2 was downregulated in PC tissues, which affected tumor TNM stage and tumor size, and low expression of CELF2 indicated a poor prognosis of PC. In vivo and in vitro experiments showed that abnormal expression of CELF2 affected the stemness, apoptosis, and proliferation of PC cells. Furthmore, we also found that CELF2 was targeted by ALKBH5 for m6A modification, leading to CELF2 degradation by YTHDF2. Bioinformatic analysis of AS model based on the TCGA database indicated that CELF2 could target CD44 to form different spliceosomes, thereby affecting the biological behavior of PC cells. The conversion of CD44s to CD44V is the key to tumorigenesis. Transcriptomic analysis was conducted to reveal the mechanism of CELF2-mediated CD44 AS in PC. We found that CELF2-mediated splicing of CD44 led to changes in the level of endoplasmic reticulum stress, further regulating the endoplasmic reticulum-associated degradation (ERAD) signaling pathway, thereby affecting apoptosis and cell stemness. In addition, ERAD signaling pathway inhibitor, EerI, could effectively reverse the effect of CD44 on tumors.
CONCLUSIONS: This study indicates that N6-methyladenosine-mediated CELF2 promotes AS of CD44, affecting the ERAD pathway and regulating the biological behavior of PC cells. CELF2 is expected to be a new target for targeted-drug development.

Keywords:  Alternative splicing; CELF2; ERAD pathway; N6-methyladenosine (m6A); Pancreatic cancer (PC)

DOI:  https://doi.org/10.1186/s13578-022-00844-0
Oncoimmunology. 2022 ;11(1): 2104551

Schweinfurthin induces ICD without ER stress and caspase activation.

Ruoheng Zhang, J D Neighbors, T D Schell, R J Hohl.

  Our previous study showed that one of the schweinfurthin compounds, 5'-methoxyschweinfurthin G (MeSG), not only enhances the anti-tumor effect of anti-PD1 antibody in the B16F10 murine melanoma model, but also provokes durable, protective anti-tumor immunity. Here we further investigated the mechanisms by which MeSG treatment induces immunogenic cell death (ICD). MeSG induced significant cell surface calreticulin (CRT) exposure in a time and concentration dependent manner as well as increased phagocytosis of tumor cells by dendritic cells in vitro. Interestingly, this CRT exposure differs from the canonical pathway in several aspects. MeSG does not cause ER stress and does not require PERK to induce CRT exposure. Caspase inhibitors partially rescue cells from MeSG-induced apoptosis, but fail to reduce CRT exposure. MeSG does not cause ERp57 exposure and the absence of ERp57 expression does not reduce CRT exposure. Finally, an intact ER to Golgi transport system is required for this phenomenon. These results lend support to the development of the schweinfurthin family as drugs to enhance clinical response to immunotherapy and highlight the need for additional research on the mechanisms of ICD induction.

Keywords:  ER stress; Immunogenic Cell Death (ICD); Schweinfurthins; apoptosis; calreticulin (CRT)

DOI:  https://doi.org/10.1080/2162402X.2022.2104551
J Toxicol Environ Health A. 2022 Aug 11. 1-16

DNA damage and reticular stress in cytotoxicity and oncotic cell death of MCF-7 cells treated with fluopsin C.

Luan Vitor Alves de Lima, Matheus Felipe da Silva, Virginia Marcia Concato, Débora Berbel Lirio Rondina, Thalita Alves Zanetti, Ingrid Felicidade, Lilian Areal Marques, Sandra Regina Lepri, Ane Stéfano Simionato, Galdino Andrade Filho, Giuliana Castello Coatti, Mário Sérgio Mantovani.

  Fluopsin C is an antibiotic compound derived from secondary metabolism of different microorganisms, which possesses antitumor, antibacterial, and antifungal activity. Related to fluopsin C antiproliferative activity, the aim of this study was to examine the following parameters: cytotoxicity, genotoxicity, cell cycle arrest, cell death induction (apoptosis), mitochondrial membrane potential (MMP), colony formation, and mRNA expression of genes involved in adaptive stress responses and cellular death utilizing a monolayer. In addition, a three-dimensional cell culture was used to evaluate the effects on growth of tumor spheroids. Fluopsin C was cytotoxic (1) producing cell division arrest in the G1 phase, (2) elevating expression of mRNA of the CDKN1A gene and (3) decrease in expression of mRNA H2AFX gene. Further, fluopsin C enhanced DNA damage as evidenced by increased expression of mRNA of GADD45A and GPX1 genes, indicating that reactive oxygen species (ROS) may be involved in the observed genotoxic response. Reticulum stress was also detected as noted from activation of the ribonuclease inositol-requiring protein 1 (IRE1) pathway, since a rise in mRNA expression of the ERN1 and TRAF2 genes was observed. During the cell death process, an increase in mRNA expression of the BBC3 gene was noted, indicating participation of this antibiotic in oncotic (ischemic) cell death. Data thus demonstrated for the first time that fluopsin C interferes with the volume of tumor spheroids, in order to attenuate their growth. Our findings show that fluopsin C modulates essential molecular processes in response to stress and cell death.

Keywords:  Antitumor; antibiotic; cell stress; programmed necrosis; spheroid

DOI:  https://doi.org/10.1080/15287394.2022.2108950
J Mol Evol. 2022 Aug 13.

uORF-Mediated Translational Regulation of ATF4 Serves as an Evolutionarily Conserved Mechanism Contributing to Non-Small-Cell Lung Cancer (NSCLC) and Stress Response.

Wenjing Xiao, Yang Sun, Jinpeng Xu, Na Zhang, Lina Dong.

  Diseases and environmental stresses are two distinct challenges for virtually all living organisms. In light of evolution, cellular responses to diseases and stresses might share similar molecular mechanisms, but the detailed regulation pathway is not reported yet.We obtained the transcriptomes and translatomes from several NSCLC (non-small-cell lung cancer) patients as well as from different species under normal or stress conditions. We found that the translation level of gene ATF4 is remarkably enhanced in NSCLC due to the reduced number of ribosomes binding to its upstream open reading frames (uORFs). We also showed the evolutionary conservation of this uORF-ATF4 regulation in the stress response of other species. Molecular experiments showed that knockdown of ATF4 reduced the cell growth rate while overexpression of ATF4 enhanced cell growth, especially for the ATF4 allele with mutated uORFs. Population genetics analyses in multiple species verified that the mutations that abolish uATGs (start codon of uORFs) are highly deleterious, suggesting the functional importance of uORFs.Our study proposes an evolutionarily conserved pattern that enhances the ATF4 translation by uORFs upon stress or disease. We generalized the concept of cellular response to diseases and stresses. These two biological processes may share similar molecular mechanisms.

Keywords:  ATF4; Evolutionarily conserved; Non-small-cell lung cancer (NSCLC); Stress response; Translation regulation; Upstream open reading frame (uORF)

DOI:  https://doi.org/10.1007/s00239-022-10068-y