The multifunction of HSP70 in cancer: Guardian or traitor to the survival of tumor cells and the next potential therapeutic target

Therapy resistance: Modulating evolutionarily conserved heat shock protein machinery in cancer

Therapy resistance is a major barrier to achieving a cure in cancer patients, often resulting in relapses and mortality. Heat shock proteins (HSPs) are a group of evolutionarily conserved proteins that play a prominent role in the progression of cancer and drug resistance. HSP synthesis is upregulated in cancer cells, facilitating adaptation to various tumor microenvironment (TME) stressors, including nutrient deprivation, exposure to DNA-damaging agents, hypoxia, and immune responses. In this review, we present background information about HSP-mediated cancer therapy resistance. Within this context, we emphasize recent progress in the understanding of HSP machinery, exploring the therapeutic potential of HSPs in cancer treatment.

Hsp70: A Multifunctional Chaperone in Maintaining Proteostasis and Its Implications in Human Disease

Hsp70, a 70 kDa molecular chaperone, plays a crucial role in maintaining protein homeostasis. It interacts with the DnaJ family of co-chaperones to modulate the functions of client proteins involved in various cellular processes, including transmembrane transport, extracellular vesicle trafficking, complex formation, and proteasomal degradation. Its presence in multiple cellular organelles enables it to mediate stress responses, apoptosis, and inflammation, highlighting its significance in disease progression. Initially recognized for its essential roles in protein folding, disaggregation, and degradation, later studies have demonstrated its involvement in several human diseases. Notably, Hsp70 is upregulated in multiple cancers, where it promotes tumor proliferation and serves as a tumor immunogen. Additionally, epichaperome networks stabilize protein-protein interactions in large and long-lived assemblies, contributing to both cancer progression and neurodegeneration. However, extracellular Hsp70 (eHsp70) in the tumor microenvironment can activate immune cells, such as natural killer (NK) cells, suggesting its potential in immunotherapeutic interventions, including CAR T-cell therapy. Given its multifaceted roles in cellular physiology and pathology, Hsp70 holds immense potential as both a biomarker and a therapeutic target across multiple human diseases. This review highlights the structural and functional importance of Hsp70, explores its role in disease pathogenesis, and discusses its potential in diagnostic and therapeutic applications.

ENO1/Hsp70 Interaction Domains: In Silico and In Vitro Insight for a Putative Therapeutic Target in Cancer

Alpha-enolase (ENO1) is a multifunctional protein with oncogenic roles. First described as a glycolytic enzyme, the protein performs different functions according to its cellular localization, post-translational modifications, and binding partners. Cell surface-localized ENO1 serves as a plasminogen-binding receptor, and it has been detected in several cell types, including various tumor cells. The plasminogen system plays a crucial role in pathological events, such as tumor cell invasion and metastasis. We have previously demonstrated that the interaction of ENO1 with the multifunctional chaperone Hsp70 increases its surface localization and the migratory and invasive capacity of breast cancer cells, thus representing a novel potential target to counteract the metastatic potential of tumors. Here, we have used computational approaches to map the putative binding region of ENO1 to Hsp70 and predict the key anchoring amino acids, also called hot spots. In vitro coimmunoprecipitation experiments were then used to validate the in silico prediction of the protein-protein interaction. This work outcome will be further used as a guide for the design of potential ENO1/HSP70 inhibitors.

GRP78 in Glioma Progression and Therapy: Implications for Targeted Approaches

Glioma is the most common primary malignant brain tumor, accounting for the majority of brain cancer-related deaths. Considering the limited efficacy of conventional therapies, novel molecular targeted therapies have been developed to improve outcomes and minimize toxicity. Glucose-regulated protein 78 (GRP78), a molecular chaperone primarily localized in the endoplasmic reticulum (ER), has received increasing attention for its role in glioma progression and resistance to conventional therapies. Overexpressed in gliomas, GRP78 supports tumor growth, survival, and therapeutic resistance by maintaining cellular homeostasis and regulating multiple signaling pathways. Its aberrant expression correlates with higher tumor grades and poorer patient prognosis. Beyond its intracellular functions, GRP78's presence on the cell surface and its role in the tumor microenvironment underscore its potential as a therapeutic target. Recent studies have explored innovative strategies to target GRP78, including small molecule inhibitors, monoclonal antibodies, and chimeric antigen receptor (CAR) T cell therapy, showing significant potential in glioma treatment. This review explores the biological characteristics of GRP78, its role in glioma pathophysiology, and the potential of GRP78-targeted therapy as a novel strategy to overcome treatment resistance and improve clinical outcomes. GRP78-targeted therapy, either alone or in combination with conventional treatments, could be a novel and attractive strategy for future glioma treatment.

Engineering Autologous Cell-Derived Exosomes to Boost Melanoma-Targeted Radio-Immunotherapy by Cascade cGAS-STING Pathway Activation

Radio-immunotherapy has offered emerging opportunities to treat invasive melanoma due to its immunostimulatory performances to activate antitumor immune responses. However, the immunosuppressive microenvironment and insufficient response rate significantly limit the practical efficacy. This study presents an autologous cell-derived exosomes (Exo)-engineered nanoagonist (MnExo@cGAMP) containing with metalloimmunotherapeutic agent (Mn2+ ions) and nucleotidyltransferase (2',3'-cGAMP, a STING agonist) for boosting melanoma-targeted radio-immunotherapy by cascade cGAS-STING pathway activation. The MnExo@cGAMP can efficiently accumulate in tumor cells due to the autologous targeting performance. Once internalized by tumor cells, the released Mn2+ ions will enhance stimulator of interferon gene (STING) binding and sensitize cyclic GMP-AMP (cGAS) to radiotherapy-induced double-straned DNA (dsNDA), resulting in amplification of cGAS-STING pathway activation together with X-ray irradiation. Meanwhile, loaded 2',3'-cGAMP can directly augment pathway activity acting as a secondary messenger. These cascade activations of cGAS-STING pathway trigger the overexpression of type I interferon, promote dendritic cells (DCs) maturation, antigen presentation, and increase CD8+ T cell activation, resulting effective radio-immunotherapeutic outcome by overcoming immune-suppression in melanoma. This study demonstrates a targeted therapeutic modality involving metalloimmunotherapy and agonist for efficient melanoma radio-immunotherapy by cascade cGAS-STING pathway activation.

Development of a novel N14-substituted antitumor evodiamine derivative with inhibiting heat shock protein 70 in non-small cell lung cancer

Notwithstanding the latest advancements in anticancer therapy, non-small cell lung cancer (NSCLC) remains a prominent contributor to cancer-associated mortality worldwide. Therefore, effective anti-cancer agents are required for the treatment of NSCLC. We previously demonstrated that the natural alkaloid evodiamine efficiently suppressed lung cancer cells and lung cancer stem-like cell populations by suppressing heat shock protein 70 (Hsp70). This finding inspired us to formulate evodiamine-based anti-cancer compounds against NSCLC. In this study, we synthesized a series of evodiamine derivatives with substitutions at the N14 position. EV206 was chosen for further study because it was the most effective among the 22 evodiamine derivatives at stopping H1299 cell growth. EV206 treatment efficiently suppressed cell viability and colony formation in both attached cells and in soft agar, even in those carrying drug resistance, by inducing apoptosis. The effectiveness of EV206 is approximately ten times greater than that of evodiamine. Normal cell viability was marginally affected by EV206 treatment. Additionally, EV206 efficiently decreased the cancer stem cell (CSC) population in the NSCLC cells. EV206 reduced the growth of H460 xenograft tumors without exhibiting toxic effects. These data implied that EV206 has the potential to be an effective Hsp70-targeting anticancer drug with low toxicity.

Targeting chaperone modifications: Innovative approaches to cancer treatment

Cancer and other chronic diseases are marked by alterations in the protein quality control system, affecting the posttranslational destiny of various proteins that regulate, structure, and catalyze cellular processes. Cellular chaperones, also known as heat shock proteins (HSPs), are pivotal in this system, performing protein triage that often determines the fate of proteins they bind to. Grasping the regulatory mechanisms of HSPs and their associated cofactors is crucial for understanding protein quality control in both healthy and diseased states. Recent research has shed light on the interactions within the protein quality control system and how post-translational modification govern protein interactions, function, and localization, which can drive or inhibit cell proliferation. This body of work encompasses critical elements of the heat shock response, including heat shock protein 70, heat shock protein 90, carboxyl-terminus of HSC70 interacting protein, and heat shock protein organizing protein. This review aims to synthesize these advancements, offering a holistic understanding of the system and its response when commandeered by diseases like cancer. We focus on the mechanistic shift in co-chaperone engagement-transitioning from heat shock protein organizing protein to carboxyl-terminus of HSC70 interacting protein in association with heat shock protein 70 and heat shock protein 90-which could influence cellular growth and survival pathways. A comprehensive examination of posttranslational modification-driven regulation within the protein quality control network is presented, highlighting the roles of activation factors, chaperones, and co-chaperones. Our insights aim to inform new strategies for therapeutically targeting diseases by considering the entire heat shock response system.

Magnetothermal-activated gene editing strategy for enhanced tumor cell apoptosis

Precise and effective initiation of the apoptotic mechanism in tumor cells is one of the most promising approaches for the treatment of solid tumors. However, current techniques such as high-temperature ablation or gene editing suffer from the risk of damage to adjacent normal tissues. This study proposes a magnetothermal-induced CRISPR-Cas9 gene editing system for the targeted knockout of HSP70 and BCL2 genes, thereby enhancing tumor cell apoptosis. The magnetothermal nanoparticulate platform is composed of superparamagnetic ZnCoFe2O4@ZnMnFe2O4 nanoparticles and the modified polyethyleneimine (PEI) and hyaluronic acid (HA) on the surface, on which plasmid DNA can be effectively loaded. Under the induction of a controllable alternating magnetic field, the mild magnetothermal effect (42℃) not only triggers dual-genome editing to disrupt the apoptosis resistance mechanism of tumor cells but also sensitizes tumor cells to apoptosis through the heat effect itself, achieving a synergistic therapeutic effect. This strategy can precisely regulate the activation of the CRISPR-Cas9 system for tumor cell apoptosis without inducing significant damage to healthy tissues, thus providing a new avenue for cancer treatment.

Tumor Dormancy and Reactivation: The Role of Heat Shock Proteins

Tumors are a heterogeneous group of cell masses originating in various organs or tissues. The cellular composition of the tumor cell mass interacts in an intricate manner, influenced by humoral, genetic, molecular, and tumor microenvironment cues that dictate tumor growth or suppression. As a result, tumors undergo a period of a dormant state before their clinically discernible stage, which surpasses the clinical dormancy threshold. Moreover, as a genetically imprinted strategy, early-seeder cells, a distinct population of tumor cells, break off to dock nearby or extravasate into blood vessels to secondary tissues, where they form disseminated solitary dormant tumor cells with reversible capacity. Among the various mechanisms underlying the dormant tumor mass and dormant tumor cell formation, heat shock proteins (HSPs) might play one of the most important roles in how the dormancy program plays out. It is known that numerous aberrant cellular processes, such as malignant transformation, cancer cell stemness, tumor invasion, metastasis, angiogenesis, and signaling pathway maintenance, are influenced by the HSPs. An accumulating body of knowledge suggests that HSPs may be involved in the angiogenic switch, immune editing, and extracellular matrix (ECM) remodeling cascades, crucial genetically imprinted strategies important to the tumor dormancy initiation and dormancy maintenance program. In this review, we highlight the biological events that orchestrate the dormancy state and the body of work that has been conducted on the dynamics of HSPs in a tumor mass, as well as tumor cell dormancy and reactivation. Additionally, we propose a conceptual framework that could possibly underlie dormant tumor reactivation in metastatic relapse.

Sensitive detection of HSP70 using a current-amplified biosensor based on antibody-loaded PS-AuNPs@Cys/Au modified ITO chip

A biosensing electrochemical platform for heat shock protein 70 (HSP70) has been developed by integrating a three-electrode indium tin oxide (ITO) on a chip. The platform includes modifications to the reference electrode and working electrode for the detection of HSP70. The new platform is constructed by assembly of HSP70 antibody on PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode to create a high HSP70 sensitive surface. The PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode is obtained by immersing the ITO electrode into the PS-AuNPs@Cys solution and performing constant potential deposition at -1.4 V (Ag/AgCl). The PS-AuNPs@Cys/Au film deposited on ITO glass provides a desirable substrate for the immobilization of the HSP70 antibody and improves the loading of antibody between PS-AuNPs@Cys/Au and the electrode resulting in a significant amplification. Under optimal conditions, the fabricated sensor demonstrates a linear range extending from 0.1 ng mL- 1 to 1000 ng mL- 1, with an impressive detection limit of 25.7 pg mL- 1 (S/N = 3). The developed immunoassay method successfully detected the HSP70 content in normal human blood samples and outperformed the ELISA method commonly used for clinical sample analysis.

Heat Shock Proteins, a Double-Edged Sword: Significance in Cancer Progression, Chemotherapy Resistance and Novel Therapeutic Perspectives

Heat shock proteins (Hsps) are involved in one of the adaptive mechanisms protecting cells against environmental and metabolic stress. Moreover, the large role of these proteins in the carcinogenesis process, as well as in chemoresistance, was noticed. This review aims to draw attention to the possibilities of using Hsps in developing new cancer therapy methods, as well as to indicate directions for future research on this topic. In order to discuss this matter, a thorough review of the latest scientific literature was carried out, taking into account the importance of selected proteins from the Hsp family, including Hsp27, Hsp40, Hsp60, Hsp70, Hsp90 and Hsp110. One of the more characteristic features of all Hsps is that they play a multifaceted role in cancer progression, which makes them an obvious target for modern anticancer therapy. Some researchers emphasize the importance of directly inhibiting the action of these proteins. In turn, others point to their possible use in the design of cancer vaccines, which would work by inducing an immune response in various types of cancer. Due to these possibilities, it is believed that the use of Hsps may contribute to the progress of oncoimmunology, and thus help in the development of modern anticancer therapies, which would be characterized by higher effectiveness and lower toxicity to the patients.

Heat Shock Response and Heat Shock Proteins: Current Understanding and Future Opportunities in Human Diseases

The heat shock response is an evolutionarily conserved mechanism that protects cells or organisms from the harmful effects of various stressors such as heat, chemicals toxins, UV radiation, and oxidizing agents. The heat shock response triggers the expression of a specific set of genes and proteins known as heat shock genes/proteins or molecular chaperones, including HSP100, HSP90, HSP70, HSP60, and small HSPs. Heat shock proteins (HSPs) play a crucial role in thermotolerance and aiding in protecting cells from harmful insults of stressors. HSPs are involved in essential cellular functions such as protein folding, eliminating misfolded proteins, apoptosis, and modulating cell signaling. The stress response to various environmental insults has been extensively studied in organisms from prokaryotes to higher organisms. The responses of organisms to various environmental stressors rely on the intensity and threshold of the stress stimuli, which vary among organisms and cellular contexts. Studies on heat shock proteins have primarily focused on HSP70, HSP90, HSP60, small HSPs, and ubiquitin, along with their applications in human biology. The current review highlighted a comprehensive mechanism of heat shock response and explores the function of heat shock proteins in stress management, as well as their potential as therapeutic agents and diagnostic markers for various diseases.

Advances in Brain Tumor Therapy Based on the Magnetic Nanoparticles

Brain tumors, including primary gliomas and brain metastases, are one of the deadliest tumors because effective macromolecular antitumor drugs cannot easily penetrate the blood-brain barrier (BBB) and blood-brain tumor barrier (BTB). Magnetic nanoparticles (MNPs) are considered the most suitable nanocarriers for the delivery of brain tumor drugs because of their unique properties compared to other nanoparticles. Numerous preclinical and clinical studies have demonstrated the potential of these nanoparticles in magnetic targeting, nuclear magnetic resonance, magnetic thermal therapy, and ultrasonic hyperthermia. To further develop and optimize MNPs for the diagnosis and treatment of brain tumors, we attempt to outline recent advances in the use of MNPs to deliver drugs, with a particular focus on their efficacy in the delivery of anti-brain tumor drugs based on magnetic targeting and low-intensity focused ultrasound, magnetic resonance imaging for surgical real-time guidance, and magnetothermal and ultrasonic hyperthermia therapy. Furthermore, we summarize recent findings on the clinical application of MNPs and the research limitations that need to be addressed in clinical translation.

Flavonoids Regulate Redox-Responsive Transcription Factors in Glioblastoma and Microglia

The tumor microenvironment (TME) has emerged as a valuable therapeutic target in glioblastoma (GBM), as it promotes tumorigenesis via an increased production of reactive oxygen species (ROS). Immune cells such as microglia accumulate near the tumor and its hypoxic core, fostering tumor proliferation and angiogenesis. In this study, we explored the therapeutic potential of natural polyphenols with antioxidant and anti-inflammatory properties. Notably, flavonoids, including fisetin and quercetin, can protect non-cancerous cells while eliminating transformed cells (2D cultures and 3D tumoroids). We tested the hypothesis that fisetin and quercetin are modulators of redox-responsive transcription factors, for which subcellular location plays a critical role. To investigate the sites of interaction between natural compounds and stress-responsive transcription factors, we combined molecular docking with experimental methods employing proximity ligation assays. Our findings reveal that fisetin decreased cytosolic acetylated high mobility group box 1 (acHMGB1) and increased transcription factor EB (TFEB) abundance in microglia but not in GBM. Moreover, our results suggest that the most powerful modulator of the Nrf2-KEAP1 complex is fisetin. This finding is in line with molecular modeling and calculated binding properties between fisetin and Nrf2-KEAP1, which indicated more sites of interactions and stronger binding affinities than quercetin.

Exosomal non-coding RNAs: Blueprint in colorectal cancer metastasis and therapeutic targets

Colorectal cancer (CRC) is ranked as the world's third-most prevalent cancer, and metastatic CRC considerably increases cancer-related fatalities globally. A number of complex mechanisms that are strictly controlled at the molecular level are involved in metastasis, which is the primary reason for death in people with CRC. Recently, it has become clear that exosomes, which are small extracellular vesicles released by non-tumorous and tumorigenic cells, play a critical role as communication mediators among tumor microenvironment (TME). To facilitate communication between the TME and cancer cells, non-coding RNAs (ncRNAs) play a crucial role and are recognized as potent regulators of gene expression and cellular processes, such as metastasis and drug resistance. NcRNAs are now recognized as potent regulators of gene expression and many hallmarks of cancer, including metastasis. Exosomal ncRNAs, like miRNAs, circRNAs, and lncRNAs, have been demonstrated to influence a number of cellular mechanisms that contribute to CRC metastasis. However, the molecular mechanisms that link exosomal ncRNAs with CRC metastasis are not well understood. This review highlights the essential roles that exosomal ncRNAs play in the progression of CRC metastatic disease and explores the therapeutic choices that are open to patients who have CRC metastases. However, exosomal ncRNA treatment strategy development is still in its early phases; consequently, additional investigation is required to improve delivery methods and find novel therapeutic targets as well as confirm the effectiveness and safety of these therapies in preclinical and clinical contexts.