COPA A-to-I RNA editing hijacks endoplasmic reticulum stress to promote metastasis in colorectal cancer

Targeting COPA to Enhance Erdafitinib Sensitivity in FGFR-Altered Bladder Cancer

Fibroblast growth factor receptor (FGFR) family aberrations are common in urothelial cancer. The FGFR tyrosine kinase inhibitor erdafitinib has been approved for locally advanced or metastatic urothelial cancer with FGFR2/3 alterations. Despite the initial efficacy of erdafitinib, resistance cannot be avoided. The molecular mechanisms underlying erdafitinib resistance have not been well investigated. Here, genome-wide CRISPR screen is performed and coatomer protein complex subunit α (COPA) is identified as a key target to enhance erdafitinib sensitivity. Functionally, the deficiency of COPA reduces the proliferation of FGFR-altered bladder cancer cells upon erdafitinib treatment. Mechanistically, COPA knockout increases the degradation of leucine-rich pentatricopeptide repeat containing (LRPPRC) protein, leading to reduced inhibitor of DNA binding 3 (ID3) mRNA stability in an m6A-dependent manner. Collectively, these findings reveal a novel mechanism of erdafitinib resistance, providing a potential therapeutic target for FGFR-altered bladder cancer.

Ginger-Derived Exosome-Like Nanoparticles Loaded With Indocyanine Green Enhances Phototherapy Efficacy for Breast Cancer

PURPOSE

Phototherapy has remarkable advantages in cancer treatment, owing to its high efficiency and minimal invasiveness. Indocyanine green (ICG) plays an important role in photo-mediated therapy. However, it has several disadvantages such as poor stability in aqueous solutions, easy aggregation of molecules, and short plasma half-life. This study aimed to develop an efficient nanoplatform to enhance the effects of photo-mediated therapy.

METHODS

We developed a novel bio-nanoplatform by integrating edible ginger-derived exosome-like nanoparticles (GDNPs) and the photosensitizer, ICG (GDNPs@ICG). GDNPs were isolated from ginger juice and loaded with ICG by co-incubation. The size distribution, zeta potential, morphology, total lipid content, and drug release behavior of the GDNPs@ICG were characterized. The photothermal performance, cellular uptake and distribution, cytotoxicity, anti-tumor effects, and mechanism of action of GDNPs@ICG were investigated both in vitro and in vivo.

RESULTS

GDNPs@ICG were taken up by tumor cells via a lipid-dependent pathway. When irradiated by an 808 nm NIR laser, GDNPs@ICG generated high levels of ROS, MDA, and local hyperthermia within the tumor, which caused lipid peroxidation and ER stress, thus enhancing the photo-mediated breast tumor therapy effect. Furthermore, in vivo studies demonstrated that engineered GDNPs@ICG significantly inhibited breast tumor growth and presented limited toxicity. Moreover, by detecting the expression of CD31, N-cadherin, IL-6, IFN-γ, CD8, p16, p21, and p53 in tumor tissues, we found that GDNPs@ICG substantially reduced angiogenesis, inhibited metastasis, activated the anti-tumor immune response, and promoted cell senescence in breast tumor.

CONCLUSION

Our study demonstrated that the novel bio-nanoplatform GDNPs@ICG enhanced the photo-mediated therapeutic effect in breast tumor. GDNPs@ICG could be an alternative for precise and efficient anti-tumor phototherapy.

metsDB: a knowledgebase of cancer metastasis at bulk, single-cell and spatial levels

Cancer metastasis, the process by which tumour cells migrate and colonize distant organs from a primary site, is responsible for the majority of cancer-related deaths. Understanding the cellular and molecular mechanisms underlying this complex process is essential for developing effective metastasis prevention and therapy strategies. To this end, we systematically analysed 1786 bulk tissue samples from 13 cancer types, 988 463 single cells from 17 cancer types, and 40 252 spots from 45 spatial slides across 10 cancer types. The results of these analyses are compiled in the metsDB database, accessible at https://relab.xidian.edu.cn/metsDB/. This database provides insights into alterations in cell constitutions, cell relationships, biological pathways, molecular biomarkers, and drug responses during cancer metastasis at bulk, single-cell, and spatial levels. Users can perform cell or gene searches to obtain multi-view and multi-scale metastasis-related data. This comprehensive resource is invaluable for understanding the metastasis process and for designing molecular therapies.

Advances in A-to-I RNA editing in cancer

RNA modifications are widespread throughout the mammalian transcriptome and play pivotal roles in regulating various cellular processes. These modifications are strongly linked to the development of many cancers. One of the most prevalent forms of RNA modifications in humans is adenosine-to-inosine (A-to-I) editing, catalyzed by the enzyme adenosine deaminase acting on RNA (ADAR) in double-stranded RNA (dsRNA). With advancements in RNA sequencing technologies, the role of A-to-I modification in cancer has garnered increasing attention. Research indicates that the levels and specific sites of A-to-I editing are significantly altered in many malignant tumors, correlating closely with tumor progression. This editing occurs in both coding and noncoding regions of RNA, influencing signaling pathways involved in cancer development. These modifications can either promote or suppress cancer progression through several mechanisms, including inducing non-synonymous amino acid mutations, altering the immunogenicity of dsRNAs, modulating mRNA interactions with microRNAs (miRNAs), and affecting the splicing of circular RNAs (circRNAs) as well as the function of long non-coding RNAs (lncRNAs). A comprehensive understanding of A-to-I RNA editing is crucial for advancing the diagnosis, treatment, and prognosis of human cancers. This review explores the regulatory mechanisms of A-to-I editing in cancers and examines their potential clinical applications. It also summarizes current research, identifies future directions, and highlights potential therapeutic implications.

CircPDIA3/miR-449a/XBP1 feedback loop curbs pyroptosis by inhibiting palmitoylation of the GSDME-C domain to induce chemoresistance of colorectal cancer

Although oxaliplatin (OXA) is widely used in the frontline treatment of colorectal cancer (CRC), CRC recurrence is commonly observed due to OXA resistance. OXA resistance is associated with a number of factors, including abnormal regulation of pyroptosis. It is therefore important to elucidate the abnormal regulatory mechanism underlying pyroptosis. Here, we identified that the circular RNA circPDIA3 played an important role in chemoresistance in CRC. CircPDIA3 could induce chemoresistance in CRC by inhibiting pyroptosis both in vitro and in vivo. Mechanistically, RIP, RNA pull-down and co-IP assays revealed that circPDIA3 directly bonded to the GSDME-C domain, subsequently enhanced the autoinhibitory effect of the GSDME-C domain through blocking the GSDME-C domain palmitoylation by ZDHHC3 and ZDHHC17, thereby restraining pyroptosis. Additionally, it was found that the circPDIA3/miR-449a/XBP1 positive feedback loop increased the expression of circPDIA3 to induce chemoresistance. Furthermore, our clinical data and patient-derived tumor xenograft (PDX) models supported the positive association of circPDIA3 with development of chemoresistance in CRC patients. Taken together, our findings demonstrated that circPDIA3 could promote chemoresistance by amplifying the autoinhibitory effect of the GSDME-C domain through inhibition of the GSDME-C domain palmitoylation in CRC. This study provides novel insights into the mechanism of circRNA in regulating pyroptosis and providing a potential therapeutic target for reversing chemoresistance of CRC.

ATF family members as therapeutic targets in cancer: From mechanisms to pharmacological interventions

The activating transcription factor (ATF)/ cAMP-response element binding protein (CREB) family represents a large group of basic zone leucine zip (bZIP) transcription factors (TFs) with a variety of physiological functions, such as endoplasmic reticulum (ER) stress, amino acid stress, heat stress, oxidative stress, integrated stress response (ISR) and thus inducing cell survival or apoptosis. Interestingly, ATF family has been increasingly implicated in autophagy and ferroptosis in recent years. Thus, the ATF family is important for homeostasis and its dysregulation may promote disease progression including cancer. Current therapeutic approaches to modulate the ATF family include direct modulators, upstream modulators, post-translational modifications (PTMs) modulators. This review summarizes the structural domain and the PTMs feature of the ATF/CREB family and comprehensively explores the molecular regulatory mechanisms. On this basis, their pathways affecting proliferation, metastasis, and drug resistance in various types of cancer cells are sorted out and discussed. We then systematically summarize the status of the therapeutic applications of existing ATF family modulators and finally look forward to the future prospect of clinical applications in the treatment of tumors by modulating the ATF family.

Construction of molecular subtype model of osteosarcoma based on endoplasmic reticulum stress and tumor metastasis-related genes

Introduction

Osteosarcoma, the prevailing primary bone malignancy among children and adolescents, is frequently associated with treatment failure primarily due to its pronounced metastatic nature.

Methods

This study aimed to establish potential associations between hub genes and subtypes for the treatment of metastatic osteosarcoma. Differentially expressed genes were extracted from patients diagnosed with metastatic osteosarcoma and a control group of non-metastatic patients, using the publicly available gene expression profile (GSE21257). The intersection of these gene sets was determined by focusing on endoplasmic reticulum (ER) stress-related genes sourced from the GeneCards database. We conducted various analytical techniques, including functional and pathway enrichment analysis, WGCNA analysis, protein-protein interaction (PPI) network construction, and assessment of immune cell infiltration, using the intersecting genes. Through this analysis, we identified potential hub genes.

Results

Osteosarcoma subtype models were developed using molecular consensus clustering analysis, followed by an examination of the associations between each subtype and hub genes. A total of 138 potential differentially expressed genes related to endoplasmic reticulum (ER) stress were identified. These genes were further investigated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) pathways. Additionally, the PPI interaction network revealed 38 interaction relationships among the top ten hub genes. The findings of the analysis revealed a strong correlation between the extent of immune cell infiltration and both osteosarcoma metastasis and the expression of hub genes. Notably, the differential expression of the top ten hub genes was observed in osteosarcoma clusters 1 and 4, signifying their significant association with the disease.

Conclusion

The identification of ten key genes linked to osteosarcoma metastasis and endoplasmic reticulum stress bears potential clinical significance. Additionally, exploring the molecular subtype of osteosarcoma has the capacity to guide clinical treatment decisions, necessitating further investigations and subsequent clinical validations.

Exploring Retrograde Trafficking: Mechanisms and Consequences in Cancer and Disease

Retrograde trafficking (RT) orchestrates the intracellular movement of cargo from the plasma membrane, endosomes, Golgi or endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) in an inward/ER-directed manner. RT works as the opposing movement to anterograde trafficking (outward secretion), and the two work together to maintain cellular homeostasis. This is achieved through maintaining cell polarity, retrieving proteins responsible for anterograde trafficking and redirecting proteins that become mis-localised. However, aberrant RT can alter the correct location of key proteins, and thus inhibit or indeed change their canonical function, potentially causing disease. This review highlights the recent advances in the understanding of how upregulation, downregulation or hijacking of RT impacts the localisation of key proteins in cancer and disease to drive progression. Cargoes impacted by aberrant RT are varied amongst maladies including neurodegenerative diseases, autoimmune diseases, bacterial and viral infections (including SARS-CoV-2), and cancer. As we explore the intricacies of RT, it becomes increasingly apparent that it holds significant potential as a target for future therapies to offer more effective interventions in a wide range of pathological conditions.