Heat Shock Factor 1 Epigenetically Stimulates Glutaminase-1-Dependent mTOR Activation to Promote Colorectal Carcinogenesis

METTL3-mediated m6A methylation of SLC38A1 stimulates cervical cancer growth

The objective of this study was to better characterize the role of the glutamine transporter SLC38A1 in cervical cancer and explore the underlying mechanisms. Data from public databases and clinical cervical cancer tissue samples were used to assess the expression of SLC38A1 and its prognostic significance. Immunohistochemical staining, qRT-PCR, and Western blotting were used to evaluate the expression of relevant genes and proteins. Cell viability, cell cycle, apoptosis, and intracellular glutamine content were measured using CCK-8, flow cytometry, and biochemical assays. Additionally, the RNA immunoprecipitation (RIP) assay was used to examine the impact of METTL3/IGF2BP3 on the m6A modification of the SLC38A1 3'UTR. Both cervical cancer specimens and cells showed significantly increased expression of SLC38A1 and its expression correlated with an unfavorable prognosis. Knockdown of SLC38A1 inhibited cell viability and cell cycle progression, induced apoptosis, and suppressed tumor growth in vivo. Glutaminase-1 inhibitor CB-839 reversed the effects of SLC38A1 overexpression. METTL3 promoted m6A modification of SLC38A1 and enhanced its mRNA stability through IGF2BP3 recruitment. Moreover, METTL3 silencing inhibited cell viability, cell cycle progression, intracellular glutamine content, and induced apoptosis, but these effects were reversed by SLC38A1 overexpression. In conclusion, METTL3-mediated m6A methylation of SLC38A1 stimulates cervical cancer progression. SLC38A1 inhibition is a potential therapeutic strategy for cervical cancer.

Glutaminolysis regulates endometrial fibrosis in intrauterine adhesion via modulating mitochondrial function

BACKGROUND

Endometrial fibrosis, a significant characteristic of intrauterine adhesion (IUA), is caused by the excessive differentiation and activation of endometrial stromal cells (ESCs). Glutaminolysis is the metabolic process of glutamine (Gln), which has been implicated in multiple types of organ fibrosis. So far, little is known about whether glutaminolysis plays a role in endometrial fibrosis.

METHODS

The activation model of ESCs was constructed by TGF-β1, followed by RNA-sequencing analysis. Changes in glutaminase1 (GLS1) expression at RNA and protein levels in activated ESCs were verified experimentally. Human IUA samples were collected to verify GLS1 expression in endometrial fibrosis. GLS1 inhibitor and glutamine deprivation were applied to ESCs models to investigate the biological functions and mechanisms of glutaminolysis in ESCs activation. The IUA mice model was established to explore the effect of glutaminolysis inhibition on endometrial fibrosis.

RESULTS

We found that GLS1 expression was significantly increased in activated ESCs models and fibrotic endometrium. Glutaminolysis inhibition by GLS1 inhibitor bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES or glutamine deprivation treatment suppressed the expression of two fibrotic markers, α-SMA and collagen I, as well as the mitochondrial function and mTORC1 signaling in ESCs. Furthermore, inhibition of the mTORC1 signaling pathway by rapamycin suppressed ESCs activation. In IUA mice models, BPTES treatment significantly ameliorated endometrial fibrosis and improved pregnancy outcomes.

CONCLUSION

Glutaminolysis and glutaminolysis-associated mTOR signaling play a role in the activation of ESCs and the pathogenesis of endometrial fibrosis through regulating mitochondrial function. Glutaminolysis inhibition suppresses the activation of ESCs, which might be a novel therapeutic strategy for IUA.

Glutamine suppresses senescence and promotes autophagy through glycolysis inhibition-mediated AMPKα lactylation in intervertebral disc degeneration

Regulating metabolic disorders has become a promising focus in treating intervertebral disc degeneration (IDD). A few drugs regulating metabolism, such as atorvastatin, metformin, and melatonin, show positive effects in treating IDD. Glutamine participates in multiple metabolic processes, including glutaminolysis and glycolysis; however, its impact on IDD is unclear. The current study reveals that glutamine levels are decreased in severely degenerated human nucleus pulposus (NP) tissues and aging Sprague-Dawley (SD) rat nucleus pulposus tissues, while lactate accumulation and lactylation are increased. Supplementary glutamine suppresses glycolysis and reduces lactate production, which downregulates adenosine-5'-monophosphate-activated protein kinase α (AMPKα) lactylation and upregulates AMPKα phosphorylation. Moreover, glutamine treatment reduces NP cell senescence and enhances autophagy and matrix synthesis via inhibition of glycolysis and AMPK lactylation, and glycolysis inhibition suppresses lactylation. Our results indicate that glutamine could prevent IDD by glycolysis inhibition-decreased AMPKα lactylation, which promotes autophagy and suppresses NP cell senescence.

Targeting the heat shock response induced by modulated electro-hyperthermia (mEHT) in cancer

The Heat Shock Response (HSR) is a cellular stress reaction crucial for cell survival against stressors, including heat, in both healthy and cancer cells. Modulated electro-hyperthermia (mEHT) is an emerging non-invasive cancer therapy utilizing electromagnetic fields to selectively target cancer cells via temperature-dependent and independent mechanisms. However, mEHT triggers HSR in treated cells. Despite demonstrated efficacy in cancer treatment, understanding the underlying molecular mechanisms for improved therapeutic outcomes remains a focus. This review examines the HSR induced by mEHT in cancer cells, discussing potential strategies to modulate it for enhanced tumor-killing effects. Approaches such as HSF1 gene-knockdown and small molecule inhibitors like KRIBB11 are explored to downregulate the HSR and augment tumor destruction. We emphasize the impact of HSR inhibition on cancer cell viability, mEHT sensitivity, and potential synergistic effects, addressing challenges and future directions. This understanding offers opportunities for optimizing treatment strategies and advancing precision medicine in cancer therapy.

Modulating the acetylation of α-tubulin by LncRNAs and microRNAs helps in the progression of cancer

Malignant tumor cells go through morphological and gene expression alterations, including rearrangement of cytoskeleton proteins that promote invasion and metastasis. Microtubules form a major cytoskeleton component that plays a significant role in regulating multiple cellular activities and function depending on the presence of posttranslational modification (PTM). Acetylation is a type of PTM that generally occurs in the lysine 40 region of α-tubulin and is known to be critically associated with cancer metastasis. Current evidence demonstrates that noncoding RNAs, such as long noncoding RNA (lncRNA) and microRNA (or miRNA), which are correlated with gene regulation modulate the expression of acetylated tubulin in the development and metastasis of cancer. This review provides an overview about the role of lncRNA and miRNA in regulation of tubulin acetylation in various types of cancer.

Enhancement of colorectal cancer therapy through interruption of the HSF1-HSP90 axis by p53 activation or cell cycle inhibition

The stress-associated molecular chaperone system is an actionable target in cancer therapies. It is ubiquitously upregulated in cancer tissues and enables tumorigenicity by stabilizing hundreds of oncoproteins and disturbing the stoichiometry of protein complexes. Most inhibitors target the key component heat-shock protein 90 (HSP90). However, although classical HSP90 inhibitors are highly tumor-selective, they fail in phase 3 clinical oncology trials. These failures are at least partly due to an interference with a negative feedback loop by HSP90 inhibition, known as heat-shock response (HSR): in response to HSP90 inhibition there is compensatory synthesis of stress-inducible chaperones, mediated by the transcription factor heat-shock factor 1 (HSF1). We recently identified that wildtype p53 (p53) actively reduces the HSR by repressing HSF1 via a p21-CDK4/6-MAPK-HSF1 axis. Here we test the hypothesis that in HSP90-based therapies simultaneous p53 activation or direct cell cycle inhibition interrupts the deleterious HSF1-HSR axis and improves the efficiency of HSP90 inhibitors. Indeed, we find that the clinically relevant p53 activator Idasanutlin suppresses the HSF1-HSR activity in HSP90 inhibitor-based therapies. This combination synergistically reduces cell viability and accelerates cell death in p53-proficient colorectal cancer (CRC) cells, murine tumor-derived organoids and patient-derived organoids (PDOs). Mechanistically, upon combination therapy human CRC cells strongly upregulate p53-associated pathways, apoptosis, and inflammatory immune pathways. Likewise, in the chemical AOM/DSS CRC model in mice, dual HSF1-HSP90 inhibition strongly represses tumor growth and remodels immune cell composition, yet displays only minor toxicities in mice and normal mucosa-derived organoids. Importantly, inhibition of the cyclin dependent kinases 4 and 6 (CDK4/6) under HSP90 inhibition phenocopies synergistic repression of the HSR in p53-proficient CRC cells. Even more important, in p53-deficient (mutp53-harboring) CRC cells, an HSP90 inhibition in combination with CDK4/6 inhibitors similarly suppresses the HSF1-HSR system and reduces cancer growth. Likewise, p53-mutated PDOs strongly respond to dual HSF1-HSP90 pathway inhibition and thus, providing a strategy to target CRC independent of the p53 status. In sum, activating p53 (in p53-proficient cancer cells) or inhibiting CDK4/6 (independent of the p53 status) provide new options to improve the clinical outcome of HSP90-based therapies and to enhance colorectal cancer therapy.

The roles and molecular mechanisms of non-coding RNA in cancer metabolic reprogramming

One of the key features of cancer is energy metabolic reprogramming which is tightly related to cancer proliferation, invasion, metastasis, and chemotherapy resistance. NcRNAs are a class of RNAs having no protein-coding potential and mainly include microRNAs, lncRNAs and circRNAs. Accumulated evidence has suggested that ncRNAs play an essential role in regulating cancer metabolic reprogramming, and the altered metabolic networks mediated by ncRNAs primarily drive carcinogenesis by regulating the expression of metabolic enzymes and transporter proteins. Importantly, accumulated research has revealed that dysregulated ncRNAs mediate metabolic reprogramming contributing to the generation of therapeutic tolerance. Elucidating the molecular mechanism of ncRNAs in cancer metabolic reprogramming can provide promising metabolism-related therapeutic targets for treatment as well as overcome therapeutic tolerance. In conclusion, this review updates the latest molecular mechanisms of ncRNAs related to cancer metabolic reprogramming.

A novel sphingolipid metabolism-related long noncoding RNA signature predicts the prognosis, immune landscape and therapeutic response in pancreatic adenocarcinoma

Sphingolipid metabolism affects prognosis and resistance to immunotherapy in patients with cancer and is an emerging target in cancer therapy with promising diagnostic and prognostic value. Long noncoding ribonucleic acids (lncRNAs) broadly regulate tumour-associated metabolic reprogramming. However, the potential of sphingolipid metabolism-related lncRNAs in pancreatic adenocarcinoma (PAAD) is poorly understood. In this study, coexpression algorithms were employed to identify sphingolipid metabolism-related lncRNAs. The least absolute shrinkage and selection operator (LASSO) algorithm was used to develop a sphingolipid metabolism-related lncRNA signature (SMLs). The prognostic predictive stability of the SMLs was validated using Kaplan-Meier. Univariate and multivariate Cox, receiver operating characteristic (ROC) and clinical stratification analyses were used to comprehensively assess the SMLs. Gene set variation analysis (GSVE), gene ontology (GO) and tumor mutation burden (TMB) analysis explored the potential mechanisms. Additionally, single sample gene set enrichment analysis (ssGSEA), ESTIMATE, immune checkpoints and drug sensitivity analysis were used to investigate the potential predictive function of the SMLs. Finally, an SMLs-based consensus clustering algorithm was utilized to differentiate patients and determine the suitable population for immunotherapy. The results showed that the SMLs consists of seven sphingolipid metabolism-related lncRNAs, which can well determine the clinical outcome of individuals with PAAD, with high stability and general applicability. In addition, the SMLs-based consensus clustering algorithm divided the TCGA-PAAD cohort into two clusters, with Cluster 1 showing better survival than Cluster 2. Additionally, Cluster 1 had a higher level of immune cell infiltration than Cluster 2, which combined with the higher levels of immune checkpoints in Cluster 1 suggests that Cluster 1 is more consistent with an immune 'hot tumor' profile and may respond better to immune checkpoint inhibitors (ICIs). This study offers new insights regarding the potential role of sphingolipid metabolism-related lncRNAs as biomarkers in PAAD. The constructed SMLs and the SMLs-based clustering are valuable tools for predicting clinical outcomes in PAAD and provide a basis for clinical selection of individualized treatments.

Heat Shock Proteins and Breast Cancer

Heat shock proteins (Hsps) are a group of stress-induced proteins involved in protein folding and maturation. Based on their molecular weight, Hsps can be divided into six families: small Hsps, Hsp40, Hsp60, Hsp70, Hsp90, and large Hsps. In the process of breast cancer tumorigenesis, Hsps play a central role in regulating cell reactions and functions including proliferation, metastasis, and apoptosis. Moreover, some of the critical Hsps also regulate the fine balance between the protective and destructive immunological responses within the tumor microenvironment. In this review, we systematically summarize the roles of major Hsps in breast cancer biology and point out the potential uses of these proteins in breast cancer diagnosis and therapy. Understanding the roles of different families of Hsps in breast cancer pathogenesis will help in the development of more effective prevention and treatment measures for breast cancer.

Proteomic characterization of the colorectal cancer response to chemoradiation and targeted therapies reveals potential therapeutic strategies

Chemoradiation and targeted therapies are the major treatments for colorectal cancer (CRC); however, molecular properties associated with therapy resistance are incompletely characterized. Here, we profile the proteome of 254 tumor tissues from patients with CRC undergoing chemotherapy, chemoradiation, or chemotherapy combined with targeted therapy. Proteome-based classification reveals four subtypes featured with distinct biological and therapeutic characteristics. The integrative analysis of CRC cell lines and clinical samples indicates that immune regulation is significantly associated with drug sensitivity. HSF1 can increase DNA damage repair and cell cycle, thus inducing resistance to radiation, while high expression of HDAC6 is negatively associated with response of cetuximab. Furthermore, we develop prognostic models with high accuracy to predict the therapeutic response, further validated by parallel reaction monitoring (PRM) assay in an independent validation cohort. This study provides a rich resource for investigating the mechanisms and indicators of chemoradiation and targeted therapy in CRC.

Kainic Acid-Induced Excitotoxicity Leads to the Activation of Heat Shock Response

Heat shock response (HSR) which is regulated by heat shock factor 1 (HSF1) is the most important mechanism and the major regulator that prevents protein aggregation in neurodegenerative diseases. Excitotoxicity, which is the accumulation of excess glutamate in synaptic cleft, is observed in age-dependent neurodegenerative diseases and also in stroke, epilepsy, and brain trauma. Only a few studies in the literature show the link between excitotoxicity and HSR. In this study, we aimed to show the molecular mechanism underlying this link. We applied heat shock (HS) treatment and induced excitotoxicity with kainic acid (KA) in neuroblastoma (SHSY-5Y) and glia (immortalized human astrocytes (IHA)) cells. We observed that, only in SHSY-5Y cells, heat shock preconditioning increases cell survival after KA treatment. GLT-1 mRNA expression is increased as a result of KA treatment and HS due to the elevation of HSF1 binding to GLT-1 promoter which was induced by HSF1 phosphorylation and sumolation in SHSY-5Y cells. Additionally, glutamine synthetase and glutaminase expressions are increased after HS preconditioning in SHSY-5Y cells indicating that HS activates glutamate metabolism modulators and accelerates the glutamate cycle. In glia cells, we did not observe the effect of HS preconditioning. In summary, heat shock preconditioning might be protective against excitotoxicity-related cell death and degeneration.

Inflammatory Bowel Diseases: An Updated Overview on the Heat Shock Protein Involvement

Inflammatory bowel diseases (IBDs) represent chronic idiopathic disorders, including Crohn's disease (CD) and ulcerative colitis (UC), in which one of the trigger factors is represented by aberrant immune interactions between the intestinal epithelium and the intestinal microbiota. The involvement of heat shock proteins (HSPs) as etiological and pathogenetic factors is becoming of increasing interest. HSPs were found to be differentially expressed in the intestinal tissues and sera of patients with CD and UC. It has been shown that HSPs can play a dual role in the disease, depending on the stage of progression. They can support the inflammatory and fibrosis process, but they can also act as protective factors during disease progression or before the onset of one of the worst complications of IBD, colorectal cancer. Furthermore, HSPs are able to mediate the interaction between the intestinal microbiota and intestinal epithelial cells. In this work, we discuss the involvement of HSPs in IBD considering their genetic, epigenetic, immune and molecular roles, referring to the most recent works present in the literature. With our review, we want to shed light on the importance of further exploring the role of HSPs, or even better, the role of the molecular chaperone system (CS), in IBD: various molecules of the CS including HSPs may have diagnostic, prognostic and therapeutic potential, promoting the creation of new drugs that could overcome the side-effects of the therapies currently used.

Recent advances microRNAs and metabolic reprogramming in colorectal cancer research

Colorectal cancer (CRC) is a cancer with the highest incidence and mortality. Alteration of gene expression is the main pathophysiological mechanism of CRC, which results in disturbed signaling pathways and cellular metabolic processes. MicroRNAs are involved in almost all pathophysiological processes and are correlative with colorectal cancer metabolism, proliferation, and chemotherapy resistance. Metabolic reprogramming, an important feature of cancer, is strongly correlative with the development and prognosis of cancers, including colorectal cancer. MicroRNAs can target enzymes involved in metabolic processes, thus playing a regulatory role in tumor metabolism. The disorder of the signaling pathway is another characteristic of tumor, which induces the occurrence and proliferation of tumors, and is closely correlative with the prognosis and chemotherapy resistance of tumor patients. MicroRNAs can target the components of the signaling pathways to regulate their transduction. Understanding the function of microRNAs in the occurrence and proliferation of CRC provides novel insights into the optimal treatment strategies, prognosis, and development of diagnosis in CRC. This article reviews the relationship between CRC and microRNA expression and hopes to provide new options for the diagnosis and treatment of CRC.

Exosome-derived circKIF20B suppresses gefitinib resistance and cell proliferation in non-small cell lung cancer

BACKGROUND

The gefitinib resistance mechanism in non-small cell lung cancer (NSCLC) remains unclear, albeit exosomal circular RNA (circRNA) is known to possibly play a vital role in it.

METHODS

We employed high-throughput sequencing techniques to detect the expressions of exosomal circRNA both in gefitinib-resistant and gefitinib-sensitive cells in this study. The circKIF20B expression was determined in serum exosomes and tissues of patients by qRT-PCR. The structure, stability, and intracellular localization of circKIF20B were verified by Sanger sequencing, Ribonuclease R (RNase R)/actinomycin D (ACTD) treatments, and Fluorescence in situ hybridization (FISH). The functions of circKIF20B were investigated by 5-Ethynyl-20-deoxyuridine (EdU), flow cytometry, Cell Counting Kit-8 (CCK-8), oxygen consumption rate (OCR), and xenograft model. Co-culture experiments were performed to explore the potential ability of exosomal circKIF20B in treating gefitinib resistance. The downstream targets of circKIF20B were determined by luciferase assay, RNA pulldown, and RNA immunoprecipitation (RIP).

RESULTS

We found that circKIF20B was poorly expressed in the serum exosomes of gefitinib-resistant patients (n = 24) and the tumor tissues of patients with NSCLC (n = 85). CircKIF20B was negatively correlated with tumor size and tumor stage. Decreasing circKIF20B was found to promote gefitinib resistance by accelerating the cell cycle, inhibiting apoptosis, and enhancing mitochondrial oxidative phosphorylation (OXPHOS), whereas increasing circKIF20B was found to restore gefitinib sensitivity. Mechanistically, circKIF20B is bound to miR-615-3p for regulating the MEF2A and then altering the cell cycle, apoptosis, and mitochondrial OXPHOS. Overexpressing circKIF20B parental cells can restore sensitivity to gefitinib in the recipient cells by upregulating the exosomal circKIF20B expression.

CONCLUSIONS

This study revealed a novel mechanism of circKIF20B/miR-615-3p/MEF2A signaling axis involving progression of gefitinib resistance in NSCLC. Exosomal circKIF20B is expected to be an easily accessible and alternative liquid biopsy candidate and potential therapeutic target in gefitinib-resistant NSCLC. The schematic diagram of mechanism in this study. Exosomal circKIF20B inhibits gefitinib resistance and cell proliferation by arresting the cell cycle, promoting apoptosis, and reducing OXPHOS via circKIF20B/miR-615-3p/MEF2A axis in NSCLC.

Amino acid metabolism regulated by lncRNAs: the propellant behind cancer metabolic reprogramming

Metabolic reprogramming is one of the main characteristics of cancer cells and plays pivotal role in the proliferation and survival of cancer cells. Amino acid is one of the key nutrients for cancer cells and many studies have focused on the regulation of amino acid metabolism, including the genetic alteration, epigenetic modification, transcription, translation and post-translational modification of key enzymes in amino acid metabolism. Long non-coding RNAs (lncRNAs) are composed of a heterogeneous group of RNAs with transcripts of more than 200 nucleotides in length. LncRNAs can bind to biological molecules such as DNA, RNA and protein, regulating the transcription, translation and post-translational modification of target genes. Now, the functions of lncRNAs in cancer metabolism have aroused great research interest and significant progress has been made. This review focuses on how lncRNAs participate in the reprogramming of amino acid metabolism in cancer cells, especially glutamine, serine, arginine, aspartate, cysteine metabolism. This will help us to better understand the regulatory mechanism of cancer metabolic reprogramming and provide new ideas for the development of anti-cancer drugs. Video Abstract.

Pan-cancer analysis of super enhancer-induced PRR7-AS1 as a potential prognostic and immunological biomarker

Introduction: Systematic pan-cancer analysis of the roles and regulatory mechanisms for PRR7-AS1 is currently not available.

Methods: In the present study, a comprehensive bioinformatic approach was used to mine the underlying oncogenic effects of PRR7-AS1, including expression status, prognostic value and immune characteristics.

Results: We discovered that PRR7-AS1 expression was remarkably upregulated in most cancer types and exhibited a negative correlation with the prognosis. Furthermore, PRR7-AS1 expression was inversely connected with the majority of tumor-infiltrating immune cells, immune scores and immune checkpoint gene expression in pancancer. There was also a significant correlation between PRR7-AS1 expression status and tumor mutational burden, microsatellite instability, and neoantigens in certain tumors. PRR7-AS1 had the best predictive power for immune checkpoint blockade efficacy compared to other well-recognized biomarkers. PRR7-AS1 overexpression could affect cytotoxic T cells-mediated antitumor responses. Functional enrichment analysis revealed that PRR7-AS1 might be involved in the metabolic pathways. Super enhancer activity might have participated in the regulation of PRR7-AS1 expression. And we constructed the competitive endogenous RNA networks for PRR7-AS1.

Discussion: In general, PRR7-AS1 had the potential to be a diagnostic, prognostic and immune biomarker for pan cancer. PRR7-AS1 was correlated with an immunosuppressive microenvironment and was a new potential target for immunotherapy. Epigenetic factors were the driving forces for PRR7-AS1 overexpression in tumors.

Targeting IGF1R signaling enhances the sensitivity of cisplatin by inhibiting proline and arginine metabolism in oesophageal squamous cell carcinoma under hypoxia

BACKGROUND

Cisplatin (DDP)-based chemotherapy is commonly adopted as the first-line treatment for patients with oesophageal squamous cell carcinoma (OSCC), but the high rate of drug resistance limits its clinical application and the underlying mechanisms at play remain unclear. The aims of this study were to elucidate the role of abnormal signal transmission and metabolism in the chemoresistance of OSCC under hypoxia and to identify targeted drugs that enhance the sensitivity of DDP chemotherapy.

METHODS

Upregulated genes in OSCC were determined by RNA sequencing (RNA-seq), the Cancer Genome Atlas (TCGA) database, immunohistochemistry (IHC), real-time quantitative PCR (RT-qPCR), and western blotting (WB). The clinicopathological significance of insulin-like growth factor-I receptor (IGF1R), argininosuccinate synthetase 1 (ASS1), and pyrroline-5-carboxylate reductase 1 (PYCR1) in OSCC was analysed using tissue micriarray (TMA). Metabolic abnormalities were determined by untargeted metabolomics analysis. The DDP-resistance role of IGF1R, ASS1, and PYCR1 in OSCC was investigated in vitro and in vivo.

RESULTS

Generally, tumour cells exist in a hypoxic microenvironment. By genomic profiling, we determined that IGF1R, as a receptor tyrosine kinase (RTK), was upregulated in OSCC under low-oxygen conditions. Clinically, enhanced IGF1R expression was associated with higher tumour stages and a poorer prognosis in OSCC patients, and its inhibitor, linsitinib, showed synergistic effects with DDP therapy in vivo and in vitro. Since oxygen-deprivation frequently lead to metabolic reprogramming, we further learned via metabolomics analysis that abnormal IGF1R pathways promoted the expression of metabolic enzymes ASS1 and PYCR1 by the transcriptional activity of c-MYC. In detail, enhanced expression of ASS1 promotes arginine metabolism for biological anabolism, whereas PYCR1 activates proline metabolism for redox balance, which maintains the proliferation ability of OSCC cells during DDP treatment under hypoxic conditions.

CONCLUSION

Enhanced expression of ASS1 and PYCR1 via IGF1R pathways rewired arginine and proline metabolism, promoting DDP resistance in OSCC under hypoxia. Linsitinib targeting IGF1R signaling may lead to promising combination therapy options for OSCC patients with DDP resistance.

Metabolic reprogramming in colorectal cancer: regulatory networks and therapy

With high prevalence and mortality, together with metabolic reprogramming, colorectal cancer is a leading cause of cancer-related death. Metabolic reprogramming gives tumors the capacity for long-term cell proliferation, making it a distinguishing feature of cancer. Energy and intermediate metabolites produced by metabolic reprogramming fuel the rapid growth of cancer cells. Aberrant metabolic enzyme-mediated tumor metabolism is regulated at multiple levels. Notably, tumor metabolism is affected by nutrient levels, cell interactions, and transcriptional and posttranscriptional regulation. Understanding the crosstalk between metabolic enzymes and colorectal carcinogenesis factors is particularly important to advance research for targeted cancer therapy strategies via the investigation into the aberrant regulation of metabolic pathways. Hence, the abnormal roles and regulation of metabolic enzymes in recent years are reviewed in this paper, which provides an overview of targeted inhibitors for targeting metabolic enzymes in colorectal cancer that have been identified through tumor research or clinical trials.

HSF1 promotes CD69+ Treg differentiation to inhibit colitis progression

Regulatory T cells (Tregs) are critical for generating and maintaining peripheral tolerance. Treg-based immunotherapy is valuable for the clinical management of diseases resulting from dysregulation of immune tolerance. However, the lack of potency is a potential limitation of Treg therapy. In addition, CD69 positive-Treg (CD69⁺ Treg) represent a newly identified subset of Tregs with potent immune suppressive capability. Methods: Foxp3 ^YFP-Cre CD69 ^fl/fl and CD4 ^Cre CD69 ^fl/fl mice were generated to determine the relevance of CD69 to Treg. Chromatin Immunoprecipitation Assay (ChIP) and luciferase Assay were performed to detect the regulation of CD69 transcription by heat shock transcription factor 1(HSF1). Gene expression was measured by western blotting and qRT-PCR. The differentiation of naive T cells to CD69⁺Foxp3⁺ iTregs was determined by flow cytometry. The immunosuppressive ability of Tregs was analyzed by ELISA and flow cytometry. Colon inflammation in mice was reflected by changes in body weight and colon length, the disease activity index (DAI), and H&E staining of colon tissues. Results: Induced Tregs (iTregs) from CD4 ^Cre CD69 ^fl/fl mice failed to alleviate colitis. The transcription factor HSF1 interacted with the promoter of the CD69 gene to prompt its transcription during Treg differentiation. Genetic and chemical inhibition of HSF1 impaired CD69⁺ Treg differentiation and promoted the pathogenesis of colitis in mice. In contrast, HSF1 protein stabilized by inhibiting its proteasomal degradation promoted CD69⁺ Treg differentiation and alleviated colitis in mice. Moreover, adoptive transfer of iTregs with HSF1 stabilization by proteasome inhibitor (PSI) dramatically prevented the development of colitis in mice and was accompanied by decreased production of pro-inflammatory cytokines and reduced accumulation of pro-inflammatory lymphocytes in colitis tissue, whereas Tregs induced in the absence of PSI were less stable and ineffective in suppressing colitis. Conclusions: HSF1 promotes CD69⁺ Tregs differentiation by activating the CD69 transcription, which is critical for the immunosuppressive function of Tregs. Stabilization of HSF1 by PSIs results in the efficient generation of Tregs with high potency to treat colitis and probably other autoimmune diseases involving Tregs deficiency.

HSF1 and Its Role in Huntington's Disease Pathology

PURPOSE OF REVIEW

Heat shock factor 1 (HSF1) is the master transcriptional regulator of the heat shock response (HSR) in mammalian cells and is a critical element in maintaining protein homeostasis. HSF1 functions at the center of many physiological processes like embryogenesis, metabolism, immune response, aging, cancer, and neurodegeneration. However, the mechanisms that allow HSF1 to control these different biological and pathophysiological processes are not fully understood. This review focuses on Huntington's disease (HD), a neurodegenerative disease characterized by severe protein aggregation of the huntingtin (HTT) protein. The aggregation of HTT, in turn, leads to a halt in the function of HSF1. Understanding the pathways that regulate HSF1 in different contexts like HD may hold the key to understanding the pathomechanisms underlying other proteinopathies. We provide the most current information on HSF1 structure, function, and regulation, emphasizing HD, and discussing its potential as a biological target for therapy.

DATA SOURCES

We performed PubMed search to find established and recent reports in HSF1, heat shock proteins (Hsp), HD, Hsp inhibitors, HSF1 activators, and HSF1 in aging, inflammation, cancer, brain development, mitochondria, synaptic plasticity, polyglutamine (polyQ) diseases, and HD.

STUDY SELECTIONS

Research and review articles that described the mechanisms of action of HSF1 were selected based on terms used in PubMed search.

RESULTS

HSF1 plays a crucial role in the progression of HD and other protein-misfolding related neurodegenerative diseases. Different animal models of HD, as well as postmortem brains of patients with HD, reveal a connection between the levels of HSF1 and HSF1 dysfunction to mutant HTT (mHTT)-induced toxicity and protein aggregation, dysregulation of the ubiquitin-proteasome system (UPS), oxidative stress, mitochondrial dysfunction, and disruption of the structural and functional integrity of synaptic connections, which eventually leads to neuronal loss. These features are shared with other neurodegenerative diseases (NDs). Currently, several inhibitors against negative regulators of HSF1, as well as HSF1 activators, are developed and hold promise to prevent neurodegeneration in HD and other NDs.

CONCLUSION

Understanding the role of HSF1 during protein aggregation and neurodegeneration in HD may help to develop therapeutic strategies that could be effective across different NDs.

Targeting HSF1 for cancer treatment: mechanisms and inhibitor development

Heat Shock Factor 1 (HSF1) is a master regulator of heat shock responsive signaling. In addition to playing critical roles in cellular heat shock response, emerging evidence suggests that HSF1 also regulates a non-heat shock responsive transcriptional network to handle metabolic, chemical, and genetic stress. The function of HSF1 in cellular transformation and cancer development has been extensively studied in recent years. Due to important roles for HSF1 for coping with various stressful cellular states, research on HSF1 has been very active. New functions and molecular mechanisms underlying these functions have been continuously discovered, providing new targets for novel cancer treatment strategies. In this article, we review the essential roles and mechanisms of HSF1 action in cancer cells, focusing more on recently discovered functions and their underlying mechanisms to reflect the new advances in cancer biology. In addition, we emphasize new advances with regard to HSF1 inhibitors for cancer drug development.

Pan-Cancer Analysis of the Roles and Driving Forces of RAB42

RAB42 is a member of the RAS family. However, the roles and driving forces for RAB42 in tumors remain elusive. In this study, we performed a comprehensive pan-cancer analysis of the roles and regulatory mechanisms of RAB42 using bioinformatics and experiments. Online databases such as Sanger Box, ACLBI and TIDE were used to search for the expression levels, prognostic value and immune features of RAB42. We observed that RAB42 expression was upregulated in most tumors and was closely associated with poor prognosis. Enrichment analysis indicated that RAB42 was related to multiple biological functions, especially the immune process. RAB42 expression had a positive correlation with immune cell infiltration and immune checkpoint gene expression. RAB42 had a high predictive value for immunotherapy efficiency. Our study screened out susceptible drugs for the RAB42 protein by sensitivity analysis and virtual screening. Many key driver genes such as TP53 contributed to RAB42 expression. DNA methylation, super-enhancer and non-coding RNAs were the epigenetic factors responsible for RAB42 expression. In brief, RAB42 could serve as a diagnostic and prognostic biomarker in many tumor types. RAB42 might be a predictive biomarker and a new target for immunotherapy. Genetic and epigenetic factors were essential for RAB42 overexpression in tumors.

A Platinum Resistance-Related lncRNA Signature for Risk Classification and Prognosis Prediction in Patients with Serous Ovarian Cancer

Accurate risk stratification for patients with serous ovarian cancer (SOC) is pivotal for treatment decisions. In this study, we identified a lncRNA-based signature for predicting platinum resistance and prognosis stratification for SOC patients. We analyzed the RNA-sequencing data and the relevant clinical information of 295 SOC samples obtained from The Cancer Genome Atlas (TCGA) database and 180 normal ovarian tissues from the Genotype-Tissue Expression (GTEx) database. A total of 284 differentially expressed lncRNAs were screened out between platinum-sensitive and platinum-resistant groups by univariate Cox regression analysis. Then, a signature consisting of eight prognostic lncRNAs was used to construct a lncRNA score model by least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression analysis. The ROC analysis showed that this signature had a good predictive performance for chemotherapy response in the training set (AUC = 0.8524) and the testing and whole sets with 0.8142 and 0.8393 of AUC, respectively. Dichotomized by the risk score of lncRNAs (lncScore), the high-risk patients showed significantly shorter progression-free survival (PFS) and overall survival (OS). Based on the final Cox model, a nomogram comprising the 8-lncRNA signature and 3 clinicopathological risk factors was then established for clinical application to predict the 1, 2, and 3-year PFS of SOC patients. The gene set enrichment analysis (GSEA) revealed that genes in the high-risk group were active in ATP synthesis, coupled electron transport, and mitochondrial respiratory chain complex assembly. Overall, our findings demonstrated the potential clinical significance of the 8-lncRNA-based classifier as a novel biomarker for outcome prediction and therapy decisions in SOC patients with platinum treatment.

Insights into the roles and driving forces of CCT3 in human tumors

CCT3 played a key role in many cancers. This study aimed to further explore the characteristics of CCT3 from a pan-cancer perspective and reveal the driving forces for CCT3. By bioinformatic analysis, we found that the mRNA and protein levels of CCT3 were abnormally elevated in most tumor types and were correlated with poor prognosis. Single-cell sequencing data indicated an abnormal increase of CCT3 expression in both malignant cells and multiple immune cells. In the tumor microenvironment, CCT3 expression was negatively relevant with immune cell infiltration and immune checkpoint genes expression. In colon cancer, knockdown of CCT3 inhibited cell proliferation. Gene set enrichment analysis showed that CCT3 may be oncogenic by regulating amino acid metabolism. Furthermore, we predicted sensitive drugs for CCT3 by virtual screening and sensitivity analysis. Many driver genes such as TP53 and KRAS were essential for CCT3 overexpression. Epigenetic factors, enhancers in particular, were also critical for CCT3 expression. Additionally, we constructed the lncRNA/circRNA-miRNA-CCT3 regulatory network. Collectively, CCT3 had the potential to be a diagnostic and prognostic biomarker for multiple tumor types. CCT3 expression was relevant with an immunosuppressive tumor microenvironment. CCT3 could be a new molecular target for colon cancer. Both genetic and epigenetic factors were responsible for CCT3 expression in tumors.

Antitumor Activities of Aqueous Cinnamon Extract on 5637 Cell Line of Bladder Cancer through Glycolytic Pathway

Background

Pharmacotherapy with medicinal plants is a promising approach to treat cancer. Cinnamon is a medicinal plant whose properties have been proven in various fields of medical sciences. Among its biological activities, its antioxidant and antiviral effects can be mentioned. In this study, the antitumor effects of Cinnamon with a focus on glucose metabolism in bladder cancer carcinoma cell-line 5637 were investigated.

Methods

Aqueous extract of Cinnamon was prepared from Cinnamon bark. Bladder cancer 5637cell line were treated with different concentrations of aqueous extract of Cinnamon. MTT was used to evaluate cell viability at 24, 48, and 72 h. The concentration of 1.25, 2.50, and 5 mg/ml was used. Apoptosis was assessed with Hochest33258 staining. For evaluating of aqueous extract of Cinnamon effect on glycolysis, the gene expression of epidermal growth factor receptor 2 (ErbB2), heat shock protein transcription factor1 (HSF1), and lactate dehydrogenase A (LDHA), as well as protein levels of HSF1 and LDHA, LDH activity, glucose consumption, and lactate production, were measured.

Results

Aqueous extract of Cinnamon significantly decreased ErbB2, HSF1, and LDHA gene expression and also decreased the protein level of HSF1 and LDHA, LDH activity, glucose consumption, and lactate production dose-dependently (p < 0.05).

Conclusion

Our finding showed that the aqueous extract of Cinnamon can inhibit proliferation in 5637 cells by inhibition of glycolysis and induction of apoptosis.

HSF1 Stimulates Glutamine Transport by Super-Enhancer-Driven lncRNA LINC00857 in Colorectal Cancer

Simple Summary

Based on the latest research, cancer cells prefer glutamine to glucose. Therefore, it is more worthwhile to explore the regulatory mechanism of glutamine metabolism in cancer cells. Super enhancers are critical for the gene transcriptional programs responsible for cell fate by interacting with various transcription factors. The transcription factor HSF1 exerts a multifaced role in tumorigenesis. However, the relevance of HSF1 to super enhancers in tumors remains obscure. Therefore, this study focused on the mechanism underlying super-enhancer activation and its relationship to HSF1 in CRC. Here, we performed a super-enhancer landscape in CRC and we screened out an HSF1-mediated super enhancer, lncRNA-LINC00857, by lncRNA microarray. We discovered that HSF1 could stimulate acetyltransferase P300-mediated super-enhancer activity to facilitate LINC00857 expression, contributing to SLC1A5/ASCT2-mediated glutamine transport. In addition, we validated that targeting the HSF1/LINC00857/ANXA11 axis may provide a valuable therapeutic strategy against CRC.

Abstract

Super enhancers are critical for the gene transcription responsible for cell fate by interacting with transcription factors. However, the relevance of HSF1 to super enhancers in tumors remains obscure. We profiled H3K27ac enrichment by chromatin immunoprecipitation sequencing. HSF1-mediated lncRNAs were identified by lncRNA microarray. The characteristics of LINC00857 were explored by in vitro and in vivo assays. The mechanism was studied via chromatin immunoprecipitation, RNA immunoprecipitation, and HSF1/ANXA11 knockout mice. We found that super enhancers occupied multiple gene loci in colorectal cancer. We screened out an HSF1-mediated super enhancer, lncRNA-LINC00857, which exerts its characteristics in promoting cell growth via regulating glutamine metabolism. Notably, HSF1 could stimulate the super-enhancer activity of LINC00857 by the enrichment of acetyltransferase P300 to its gene loci, contributing to LINC00857 transcription. In turn, nuclear LINC00857 cooperated with HSF1 to promote ANXA11 transcription, which modulated SLC1A5/ASCT2 protein expression by binding competitively to miR-122-5p. The knockout of ANXA11 attenuated colorectal cancer formation in vivo. Collectively, we shed light on a closely cooperative machinery between HSF1 and super enhancers. HSF1 could stimulate acetyltransferase P300-mediated super-enhancer activity to facilitate LINC00857 expression, contributing to SLC1A5-mediated glutamine transport. Targeting the HSF1/LINC00857/ANXA11 axis may provide a valuable therapeutic strategy against colorectal cancer.

Advances of Heat Shock Family in Ulcerative Colitis

Ulcerative Colitis (UC) is a non-specific and chronic inflammatory disease of colonic mucosa whose exact etiology and mechanisms remain unclear. The incidence rate of UC is increasing year by year worldwide. What followed is that the medical costs are also rising rapidly. Therefore, it is urgent to understand the pathogenesis and find promising therapeutic targets for UC. Intestinal mucosal homeostasis is essential for normal bowel function, and its imbalance may be an important pathogenesis of UC. Endogenous homeostatic regulators play roles in repairing intestinal mucosa injury after stress. Heat shock family proteins are essential endogenous homeostasis factors. They can inhibit inflammation, regulate intestinal epithelial cells’ survival and death, and promote mucosal healing. Thus, they play important roles in sustaining intestinal mucosal homeostasis and protecting against UC progression. However, the heat shock family may promote UC carcinogenesis. Here, we summarize the advances in the research of the functions of the heat shock family in UC. And this review is an attempt to light on the etiopathogenesis of UC, highlighting the endogenous protective mechanisms, hoping to provide a novel therapeutic target for UC treatment.

Tracking the Activation of Heat Shock Signaling in Cellular Protection and Damage

Heat Shock (HS) signaling is activated in response to various types of cellular stress. This activation serves to protect cells from immediate threats in the surrounding environment. However, activation of HS signaling occurs in a heterogeneous manner within each cell population and can alter the epigenetic state of the cell, ultimately leading to long-term abnormalities in body function. Here, we summarize recent research findings obtained using molecular and genetic tools to track cells where HS signaling is activated. We then discuss the potential further applications of these tools, their limitations, and the necessary caveats in interpreting data obtained with these tools.

Heat Shock Proteins and HSF1 in Cancer

Fitness of cells is dependent on protein homeostasis which is maintained by cooperative activities of protein chaperones and proteolytic machinery. Upon encountering protein-damaging conditions, cells activate the heat-shock response (HSR) which involves HSF1-mediated transcriptional upregulation of a group of chaperones - the heat shock proteins (HSPs). Cancer cells experience high levels of proteotoxic stress due to the production of mutated proteins, aneuploidy-induced excess of components of multiprotein complexes, increased translation rates, and dysregulated metabolism. To cope with this chronic state of proteotoxic stress, cancers almost invariably upregulate major components of HSR, including HSF1 and individual HSPs. Some oncogenic programs show dependence or coupling with a particular HSR factor (such as frequent coamplification of HSF1 and MYC genes). Elevated levels of HSPs and HSF1 are typically associated with drug resistance and poor clinical outcomes in various malignancies. The non-oncogene dependence ("addiction") on protein quality controls represents a pancancer target in treating human malignancies, offering a potential to enhance efficacy of standard and targeted chemotherapy and immune checkpoint inhibitors. In cancers with specific dependencies, HSR components can serve as alternative targets to poorly druggable oncogenic drivers.

Stress Responses as Master Keys to Epigenomic Changes in Transcriptome and Metabolome for Cancer Etiology and Therapeutics

From initiation through progression, cancer cells are subjected to a magnitude of endogenous and exogenous stresses, which aid in their neoplastic transformation. Exposure to these classes of stress induces imbalance in cellular homeostasis and, in response, cancer cells employ informative adaptive mechanisms to rebalance biochemical processes that facilitate survival and maintain their existence. Different kinds of stress stimuli trigger epigenetic alterations in cancer cells, which leads to changes in their transcriptome and metabolome, ultimately resulting in suppression of growth inhibition or induction of apoptosis. Whether cancer cells show a protective response to stress or succumb to cell death depends on the type of stress and duration of exposure. A thorough understanding of epigenetic and molecular architecture of cancer cell stress response pathways can unveil a plethora of information required to develop novel anticancer therapeutics. The present view highlights current knowledge about alterations in epigenome and transcriptome of cancer cells as a consequence of exposure to different physicochemical stressful stimuli such as reactive oxygen species (ROS), hypoxia, radiation, hyperthermia, genotoxic agents, and nutrient deprivation. Currently, an anticancer treatment scenario involving the imposition of stress to target cancer cells is gaining traction to augment or even replace conventional therapeutic regimens. Therefore, a comprehensive understanding of stress response pathways is crucial for devising and implementing novel therapeutic strategies.

The Regulatory Network of MicroRNA in the Metabolism of Colorectal Cancer

Colorectal cancer (CRC) is the third most common malignant tumor in the world. During the progression of CRC, the entire metabolic network undergoes reprogramming, including marked changes in the regulation of glucose, lipid and amino acid metabolism. Although microRNAs (miRNAs) account for only 1% of the entire human genome, they play an important role in almost all physiological and pathological processes in the body. MiRNAs can react directly with key enzymes in the metabolic processes. MiRNAs also interact with other ncRNAs, as a member of non-coding RNA (ncRNA), to form their own regulatory network in various oncogenic pathways of CRC metabolism. The progression of colorectal cancer is closely related to the intestinal flora, where miRNAs act as important mediators. Understanding how miRNAs act in the regulatory network of CRC metabolism is helpful to elucidate the characteristics of tumor occurrence, proliferation, metastasis and drug resistance. This review summarizes the role of miRNAs in the metabolism of CRC and how miRNAs interact with key enzymes, ncRNA and intestinal flora to further discuss how miRNAs affect CRC and realize some new strategies for the early diagnosis and treatment of CRC.

Integrated bioinformatics and experiments reveal the roles and driving forces for HSF1 in colorectal cancer

Heat shock factor 1 (HSF1) has watershed significance in different tumors. However, the roles and driving forces for HSF1 in colorectal cancer (CRC) are poorly understood. Our study integrally analyzed the roles and driving forces for HSF1 in CRC by bioinformatics and experiments. The expression and prognostic characteristics of HSF1 were analyzed via UALCAN, GEPIA2, TISIDB, Prognoscan and HPA databases. Then, we analyzed the correlation between HSF1 expression and immune features via TIMER2 database. Subsequently, we explored the driving forces for HSF1 abnormal expression in CRC by bioinformatics and experiments. Our results showed that HSF1 was overexpressed and correlated with poor prognosis in CRC. And the expression of HSF1 was significantly correlated with multiple immune cell infiltration and was negatively correlated with immunomodulators such as programmed cell death 1 ligand 1(PD-L1). Along with many driver genes in particular TP53, super-enhancer, miRNA and DNA methylation were all responsible for HSF1 overexpression in CRC. Moreover, we demonstrated that β-catenin could promote the translation process of HSF1 mRNA by interacting with HuR, which could directly bind to the coding sequence (CDS) region of HSF1 mRNA. Collectively, HSF1 may be useful as a diagnostic and prognostic biomarker for CRC. HSF1 was closely correlated with immune features. Genetic and epigenetic alterations contributed to HSF1 overexpression in CRC. More importantly, we demonstrated that HSF1 may be regulated at the level of mRNA translation by β-catenin-induced HuR activity.

The Relationship Between the Network of Non-coding RNAs-Molecular Targets and N6-Methyladenosine Modification in Colorectal Cancer

Recent accumulating researches implicate that non-coding RNAs (ncRNAs) including microRNA (miRNA), circular RNA (circRNA), and long non-coding RNA (lncRNAs) play crucial roles in colorectal cancer (CRC) initiation and development. Notably, N6-methyladenosine (m⁶A) methylation, the critical posttranscriptional modulators, exerts various functions in ncRNA metabolism such as stability and degradation. However, the interaction regulation network among ncRNAs and the interplay with m⁶A-related regulators has not been well documented, particularly in CRC. Here, we summarize the interaction networks and sub-networks of ncRNAs in CRC based on a data-driven approach from the publications (IF > 6) in the last quinquennium (2016–2021). Further, we extend the regulatory pattern between the core m⁶A regulators and m⁶A-related ncRNAs in the context of CRC metastasis and progression. Thus, our review will highlight the clinical potential of ncRNAs and m⁶A modifiers as promising biomarkers and therapeutic targets for improving the diagnostic precision and treatment of CRC.

Anticancer Effects of Cinnamaldehyde through Inhibition of ErbB2/HSF1/LDHA Pathway in 5637 Cell Line of Bladder Cancer

BACKGROUND

The growing prevalence of bladder cancer worldwide has become a major concern for the researchers, and the side effects of chemotherapy drugs have always been a major problem in cancer treatment. Cinnamaldehyde, the active ingredient in the Cinnamon plant, has long been considered with anti-oxidant and anti-inflammatory effects.

METHODS

Bladder cancer 5637 cell lines were treated with the different concentrations of Cinnamaldehyde. MTT assay was performed to evaluate cell viability at 24, 48, and 72 hours. The concentration of 0.02, 0.04, and 0.08 mg/ml of Cinnamaldehyde were selected. Apoptosis was assessed with Annexin V-FITC/PI and Hochest33258 staining. Cell migration was performed by the scratch test. To evaluate Cinnamaldehyde effect on glycolysis, the gene expression of epidermal growth factor receptor 2 (ErbB2), heat shock protein transcription factor-1 (HSF1) and lactate dehydrogenase A (LDHA), as well as the protein levels of HSF1 and LDHA, LDH activity and finally glucose consumption and lactate production, were measured.

RESULTS

Cinnamaldehyde significantly increased apoptosis rate in the 5637 cells (p<0.05). Furthermore, it significantly reduced the gene expression of ErbB2, HSF1, and LDHA, protein level of HSF1 and LDHA, LDH activity, as well as cell migration, glucose consumption, and lactate production (p<0.05). These changes were dose-dependent.

CONCLUSION

Thus, Cinnamaldehyde induced apoptosis and decreased growth in 5637 cells by reducing ErbB2-HSF1-LDHA pathway.

Targeting ATF4-dependent pro-survival autophagy to synergize glutaminolysis inhibition

As glutamine plays a central role in cancer metabolism, inhibition of glutaminolysis has become an ideal anticancer therapeutic target. However, glutaminolysis inhibition leads to activation of autophagy, which compromises its antitumor effect. Hence, we investigated the mechanism underlying glutaminolysis inhibition-induced pro-survival autophagy.

Methods: High-throughput sequencing was performed on colorectal cancer (CRC) cells before and after glutaminolysis inhibition to identify differentially expressed genes. Activating transcription factor 4 (ATF4) pathway enrichment in glutaminolysis inhibited cells was identified through gene set enrichment analysis. ATF4 expression was assessed by quantitative real-time PCR (qRT-PCR) and western blotting. The function of ATF4 on mechanistic target of rapamycin (mTOR) regulation was assessed by western blotting. Luciferase reporter assays and chromatin immunoprecipitation were used to confirm the regulation of DNA damage inducible transcript 4 (DDIT4) by ATF4. mRNA half-life assays, RNA immunoprecipitation, qRT-PCR and western blotting were performed to determine the relationship between FTO alpha-ketoglutarate dependent dioxygenase (FTO), YTH N⁶-methyladenosine RNA binding protein 2 (YTHDF2), and ATF4. ATF4 regulation of pro-survival autophagy was measured by tandem monomeric red fluorescent protein-green fluorescent protein fluorescence microscopy. Finally, the synergistic effect of autophagy and glutaminolysis inhibition was analyzed in an azoxymethane/dextran sodium sulfate mouse model.

Results: The ATF4 pathway was activated in CRC cells upon glutaminolysis inhibition. Functionally, ATF4 transcriptionally upregulated DDIT4 to suppress mTOR, which induced pro-survival autophagy during glutaminolysis inhibition. Interestingly, glutaminolysis inhibition promoted ATF4 mRNA expression by abrogating N⁶-methyladenosine (m⁶A) modification and YTHDF2-mediated RNA decay. Finally, inhibition of ATF4-induced autophagy enhanced the antitumor efficacy of glutaminolysis inhibition.

Conclusion: Glutaminolysis inhibition upregulated ATF4 expression in an m⁶A-dependent manner to activate pro-survival autophagy through transcriptional activation of the mTOR inhibitor DDIT4. Targeting ATF4-induced autophagy is a new strategy to synergize glutaminolysis-targeting therapies for cancer treatment.

Suppression of HSF1 activity by wildtype p53 creates a driving force for p53 loss-of-heterozygosity

The vast majority of human tumors with p53 mutations undergo loss of the remaining wildtype p53 allele (loss-of-heterozygosity, p53LOH). p53LOH has watershed significance in promoting tumor progression. However, driving forces for p53LOH are poorly understood. Here we identify the repressive WTp53-HSF1 axis as one driver of p53LOH. We find that the WTp53 allele in AOM/DSS chemically-induced colorectal tumors (CRC) of p53R248Q/+ mice retains partial activity and represses heat-shock factor 1 (HSF1), the master regulator of the proteotoxic stress response (HSR) that is ubiquitously activated in cancer. HSR is critical for stabilizing oncogenic proteins including mutp53. WTp53-retaining CRC tumors, tumor-derived organoids and human CRC cells all suppress the tumor-promoting HSF1 program. Mechanistically, retained WTp53 activates CDKN1A/p21, causing cell cycle inhibition and suppression of E2F target MLK3. MLK3 links cell cycle with the MAPK stress pathway to activate the HSR response. In p53R248Q/+ tumors WTp53 activation by constitutive stress represses MLK3, thereby weakening the MAPK-HSF1 response necessary for tumor survival. This creates selection pressure for p53LOH which eliminates the repressive WTp53-MAPK-HSF1 axis and unleashes tumor-promoting HSF1 functions, inducing mutp53 stabilization enabling invasion.

Basic approaches, challenges and opportunities for the discovery of small molecule anti-tumor drugs

Chemotherapy is one of the main treatments for cancer, especially for advanced cancer patients. In the past decade, significant progress has been made with the research into the molecular mechanisms of cancer cells and the precision medicine. The treatment on cancer patients has gradually changed from cytotoxic chemotherapy to precise treatment strategy. Research into anticancer drugs has also changed from killing effects on all cells to targeting drugs for target genes. Besides, researchers have developed the understanding of the abnormal physiological function, related genomics, epigenetics, and proteomics of cancer cells with cancer genome sequencing, epigenetic research, and proteomic research. These technologies and related research have accelerated the development of related cancer drugs. In this review, we summarize the research progress of anticancer drugs, the current challenges, and future opportunities.

Targeting GLS1 to cancer therapy through glutamine metabolism

Glutamine metabolism is one of the hallmarks of cancers which is described as an essential role in serving as a major energy and building blocks supply to cell proliferation in cancer cells. Many malignant tumor cells always display glutamine addiction. The "kidney-type" glutaminase (GLS1) is a metabolism enzyme which plays a significant part in glutaminolysis. Interestingly, GLS1 is often overexpressed in highly proliferative cancer cells to fulfill enhanced glutamine demand. So far, GLS1 has been proved to be a significant target during the carcinogenesis process, and emerging evidence reveals that its inhibitors could provide a benefit strategy for cancer therapy. Herein, we summarize the prognostic value of GLS1 in multiple cancer type and its related regulatory factors which are associated with antitumor activity. Moreover, this review article highlights the remarkable reform of discovery and development for GLS1 inhibitors. On the basis of case studies, our perspectives for targeting GLS1 and development of GLS1 antagonist are discussed in the final part.

Paving the way for small-molecule drug discovery

Small-molecule drugs are organic compounds affecting molecular pathways by targeting important proteins, which have a low molecular weight, making them penetrate cells easily. Small-molecule drugs can be developed from leads derived from rational drug design or isolated from natural resources. As commonly used medications, small-molecule drugs can be taken orally, which enter cells to act on intracellular targets. These characteristics make small-molecule drugs promising candidates for drug development, and they are increasingly favored in the pharmaceutical market. Despite the advancements in molecular genetics and effective new processes in drug development, the drugs currently used in clinical practice are inadequate due to their poor efficacy or severe side effects. Therefore, developing new safe and efficient drugs is a top priority for disease control and curing.

Prognostic Signature of Immune Genes and Immune-Related LncRNAs in Neuroblastoma: A Study Based on GEO and TARGET Datasets

Background

The prognostic value of immune-related genes and lncRNAs in neuroblastoma has not been elucidated, especially in subgroups with different outcomes. This study aimed to explore immune-related prognostic signatures.

Materials and Methods

Immune-related prognostic genes and lncRNAs were identified by univariate Cox regression analysis in the training set. The top 20 C-index genes and 17 immune-related lncRNAs were included in prognostic model construction, and random forest and the Least Absolute Shrinkage and Selection Operator (LASSO) regression algorithms were employed to select features. The risk score model was constructed and assessed using the Kaplan-Meier plot and the receiver operating characteristic curve. Functional enrichment analysis of the immune-related lncRNAs was conducted using the STRING database.

Results

In GSE49710, five immune genes (CDK4, PIK3R1, THRA, MAP2K2, and ULBP2) were included in the risk score five genes (RS5_G) signature, and eleven immune-related lncRNAs (LINC00260, FAM13A1OS, AGPAT4-IT1, DUBR, MIAT, TSC22D1-AS1, DANCR, MIR137HG, ERC2-IT1, LINC01184, LINC00667) were brought into risk score LncRNAs (RS_Lnc) signature. Patients were divided into high/low-risk score groups by the median. Overall survival and event/progression-free survival time were shortened in patients with high scores, both in training and validation cohorts. The same results were found in subgroups. In grouping ability assessment, the area under the curves (AUCs) in distinguishing different groups ranged from 0.737 to 0.94, better in discriminating MYCN status and high risk in training cohort (higher than 0.9). Multivariate Cox analysis demonstrated that RS5_G and RS_Lnc were the independent risk factors for overall and event/progression-free survival (all p-values <0.001). Correlation analysis showed that RS5_G and RS_Lnc were negatively associated with aDC, CD8+ T cells, but positively correlated with Th2 cells. Functional enrichment analyzes demonstrated that immune-related lncRNAs are mainly enriched in cancer-related pathways and immune-related pathways.

Conclusion

We identified the immune-related prognostic signature RS5_G and RS_Lnc. The predicting and grouping ability is close to being even better than those reported in other studies, especially in subgroups. This study provided prognostic signatures that may help clinicians to choose optimal treatment strategies and showed a new insight for NB treatment. These results need further biological experiments and clinical validation.

Mechanism of miR-455-3 in suppressing epithelial-mesenchymal transition and angiogenesis of non-small cell lung cancer cells

The tumor-suppressing role of miR-455-3p has been reported in lung cancer, but the working mechanism remains to be fully elucidated. This study aims to explore the possible mechanism of miR-455-3p in regulating epithelial-mesenchymal transition (EMT) progression and angiogenesis in non-small cell lung cancer (NSCLC) cells.The expressions of miR-455-3p, HSF1, GLS1, and EMT-related proteins (E-cadherin, N-cadherin, vimentin, and Snail-1) in both NSCLC tissues and cell lines were determined by RT-qPCR and western blot. After cell transfection, cell proliferation and angiogenesis ability on NSCLC cells were assessed by MTT and tube formation assay. The binding of miR-455-3p with HSF1 was measured by luciferase reporter gene assay, while the interaction between HSF1 and GLS1 was determined by co-immunoprecipitation assay (Co-IP).HSF1 was highly expressed in NSCLC tissues and cells. Inhibition of HSF1 expression or overexpression of miR-455-3p in NSCLC cells can suppress cell proliferation, angiogenesis ability, and EMT progression. miR-455-3p was found to negatively regulate HSF1 expression. Co-transfection of miR-455-3p overexpression and HSF1 inhibition in NSCLC cells showed that miR-455-3p can partially counteract the effect of HSF1 in NSCLC cells. HSF1 can interact with GLS1 and elevate the expression of GLS1. GLS1 can partially abolish the suppressive effect of miR-455-3p in NSCLC cells.miR-455-3p can bind HSF1 to suppress the GLS1 in NSCLC cells, therefore suppressing EMT progression and angiogenesis of NSCLC cells.

Transporters at the Interface between Cytosolic and Mitochondrial Amino Acid Metabolism

Mitochondria are central organelles that coordinate a vast array of metabolic and biologic functions important for cellular health. Amino acids are intricately linked to the bioenergetic, biosynthetic, and homeostatic function of the mitochondrion and require specific transporters to facilitate their import, export, and exchange across the inner mitochondrial membrane. Here we review key cellular metabolic outputs of eukaryotic mitochondrial amino acid metabolism and discuss both known and unknown transporters involved. Furthermore, we discuss how utilization of compartmentalized amino acid metabolism functions in disease and physiological contexts. We examine how improved methods to study mitochondrial metabolism, define organelle metabolite composition, and visualize cellular gradients allow for a more comprehensive understanding of how transporters facilitate compartmentalized metabolism.

Glutaminase in microglia: A novel regulator of neuroinflammation

Neuroinflammation is the inflammatory responses that are involved in the pathogenesis of most neurological disorders. Glutaminase (GLS) is the enzyme that catalyzes the hydrolysis of glutamine to produce glutamate. Besides its well-known role in cellular metabolism and excitatory neurotransmission, GLS has recently been increasingly noticed to be up-regulated in activated microglia under pathological conditions. Furthermore, GLS overexpression induces microglial activation, extracellular vesicle secretion, and neuroinflammatory microenvironment formation, which, are compromised by GLS inhibitors in vitro and in vivo. These results indicate that GLS has more complicated implications in brain disease etiology than what are previously known. In this review, we introduce GLS isoforms, expression patterns in the body and the brain, and expression/activities regulation. Next, we discuss the metabolic and neurotransmission functions of GLS. Afterwards, we summarize recent findings of GLS-mediated microglial activation and pro-inflammatory extracellular vesicle secretion, which, in turns, induces neuroinflammation. Lastly, we provide a comprehensive discussion for the involvement of microglial GLS in the pathogenesis of various neurological disorders, indicating microglial GLS as a promising target to treat these diseases.

Systematic analysis using a bioinformatics strategy identifies SFTA1P and LINC00519 as potential prognostic biomarkers for lung squamous cell carcinoma

Lung cancer has high incidence and mortality rates, in which lung squamous cell carcinoma (LUSC) is a primary type of non-small cell lung carcinoma (NSCLC). The aim of our study was to discover long non-coding RNAs (lncRNAs) associated with diagnose and prognosis for LUSC. RNA sequencing data obtained from LUSC samples were extracted from The Cancer Genome Atlas database (TCGA). Two prognosis-associated lncRNAs (including SFTA1P and LINC00519) were selected from LUSC samples, and the expression levels were also verified to be associated abnormal in LUSC clinical samples. Our findings demonstrate that lncRNAs SFTA1P and LINC00519 exert important functions in human LUSC and may serve as new targets for LUSC diagnosis and therapy.

Heat Shock Factor 1-dependent extracellular matrix remodeling mediates the transition from chronic intestinal inflammation to colon cancer

In the colon, long-term exposure to chronic inflammation drives colitis-associated colon cancer (CAC) in patients with inflammatory bowel disease. While the causal and clinical links are well established, molecular understanding of how chronic inflammation leads to the development of colon cancer is lacking. Here we deconstruct the evolving microenvironment of CAC by measuring proteomic changes and extracellular matrix (ECM) organization over time in a mouse model of CAC. We detect early changes in ECM structure and composition, and report a crucial role for the transcriptional regulator heat shock factor 1 (HSF1) in orchestrating these events. Loss of HSF1 abrogates ECM assembly by colon fibroblasts in cell-culture, prevents inflammation-induced ECM remodeling in mice and inhibits progression to CAC. Establishing relevance to human disease, we find high activation of stromal HSF1 in CAC patients, and detect the HSF1-dependent proteomic ECM signature in human colorectal cancer. Thus, HSF1-dependent ECM remodeling plays a crucial role in mediating inflammation-driven colon cancer.

Heat Shock Factor 1 in Relation to Tumor Angiogenesis and Disease Progression in Patients With Pancreatic Cancer

OBJECTIVE

In this article, the aims were to study the expression of heat shock factor 1 (HSF1) in patients with pancreatic cancer and to elucidate the relevance between HSF1, angiogenesis, clinicopathological factors, and prognosis.

METHODS

Pancreatic cancer, paracancerous, and normal pancreatic tissues were collected. The HSF1 RNA and protein expressions were identified using quantitative real-time reverse transcription polymerase chain reaction and immunohistochemical staining. Associations of HSF1 and cluster of differentiation 34 with clinical variables and disease outcomes were investigated.

RESULTS

Compared with the normal pancreatic and paracancerous tissue, HSF1 RNA and protein significantly showed higher expression in the pancreatic cancer tissue and was significantly associated with microvessel density. The high expression of HSF1 did not correspond to the patients' sex, age, carcinoembryonic antigen level, diameter of tumors, and locations; however, it corresponded significantly with carbohydrate antigen 19-9 level, lymph node metastasis, tumor node metastasis stage, differentiation degree, vascular invasion, and distant metastasis. The expression levels of HSF1 and cluster of differentiation 34 were significantly correlated with prognosis, disease specificity, and survival. The high expression of HSF1 would lead to worse prognosis and decrease in survival time and disease-free survival time.

CONCLUSIONS

HSF1 expression level in pancreatic cancer tissue could be an ideal prognostic biomarker for risk stratification and a potential therapeutic target for patients with pancreatic cancer.

β-catenin represses miR455-3p to stimulate m6A modification of HSF1 mRNA and promote its translation in colorectal cancer

Background

Heat shock transcription factor1 (HSF1) was overexpressed to promote glutaminolysis and activate mTOR in colorectal cancer (CRC). Here, we investigated the mechanism for cancer-specific overexpression of HSF1.

Methods

HSF1 expression was analyzed by chromatin immunoprecipitation, qRT-PCR, immunohistochemistry staining and immunoblotting. HSF1 translation was explored by polysome profiling and nascent protein analysis. Biotin pulldown and m6A RNA immunoprecipitation were applied to investigate RNA/RNA interaction and m6A modification. The relevance of HSF1 to CRC was analyzed in APC^min/+ and APC^min/+ HSF1^+/−mice.

Results

HSF1 expression and activity were reduced after the inhibition of WNT/β-catenin signaling by pyrvinium or β-catenin knockdown, but elevated upon its activation by lithium chloride (LiCl) or β-catenin overexpression. There are much less upregulated genes in HSF1-KO MEF treated with LiCl when compared with LiCl-treated WT MEF. HSF1 protein expression was positively correlated with β-catenin expression in cell lines and primary tissues. After β-catenin depletion, HSF1 mRNA translation was impaired, accompanied by the reduction of its m6A modification and the upregulation of miR455-3p, which can interact with 3′-UTR of HSF1 mRNA to repress its translation. Interestingly, inhibition of miR455-3p rescued β-catenin depletion-induced reduction of HSF1 m6A modification and METTL3 interaction. Both the size and number of tumors were significantly reduced in APC^min/+ mice when HSF1 was genetically knocked-out or chemically inhibited.

Conclusions

β-catenin suppresses miR455-3p generation to stimulate m6A modification and subsequent translation of HSF1 mRNA. HSF1 is important for β-catenin to promote CRC development. Targeting HSF1 could be a potential strategy for the intervention of β-catenin-driven cancers.

Targeting Colorectal Cancer Stem Cells as an Effective Treatment for Colorectal Cancer

As one of the common cancers that threaten human life, the recurrence and metastasis of colorectal cancer seriously affect the prognosis of patients. Although new drugs and comprehensive treatments have been adopted, the current treatment effect on this tumor, especially in advanced colorectal cancer, is still not satisfactory. More and more evidence shows that tumors are likely to be a stem cell disease. In recent years, the rise of cancer stem cell theory has provided a new way for cancer treatment. Studies have found that a small number of special cells in colorectal cancer tissues that induce tumorigenesis, proliferation, and promote tumor migration and metastasis, namely, colorectal cancer stem cells. Colorectal cancer stem cells are defined with a group of cell-surface markers, such as CD44, CD133, CD24, epithelial cell adhesion factor molecule, LGR5, and acetaldehyde dehydrogenase. They are highly tumorigenic, aggressive, and chemoresistant and thus are critical in the metastasis and recurrence of colorectal cancer. Therefore, targeting colorectal cancer stem cells may become an important research direction for the future cure of colorectal cancer.

Emerging roles of HSF1 in cancer: Cellular and molecular episodes

Heat shock factor 1 (HSF1) systematically guards proteome stability and proteostasis by regulating the expression of heat shock protein (HSP), thus rendering cancer cells addicted to HSF1. The non-canonical transcriptional programme driven by HSF1, which is distinct from the heat shock response (HSR), plays an indispensable role in the initiation, promotion and progression of cancer. Therefore, HSF1 is widely exploited as a potential therapeutic target in a broad spectrum of cancers. Various molecules and signals in the cell jointly regulate the activation and attenuation of HSF1. The high-level expression of HSF1 in tumours and its relationship with patient prognosis imply that HSF1 can be used as a biomarker for patient prognosis and a target for cancer treatment. In this review, we discuss the newly identified mechanisms of HSF1 activation and regulation, the diverse functions of HSF1 in tumourigenesis, and the feasibility of using HSF1 as a prognostic marker. Disrupting cancer cell proteostasis by targeting HSF1 represents a novel anti-cancer therapeutic strategy.