Membrane-anchored heat-shock protein 70 (Hsp70) in cancer

Tumor-derived Hsp70-CD14 interaction enhances the antitumor potential of cytotoxic T cells by activating tumor-associated macrophages to express CC chemokines and CD40 costimulatory molecules

Heat shock proteins are a widely distributed group of proteins. It is constitutively expressed in almost all organisms and shows little variation throughout evolution. Previously, HSPs, particularly Hsp70, were recognized as molecular chaperones that aid in the proper three-dimensional folding of newly synthesized polypeptides in cells. Recently, researchers have focused on the potential induction of immune cells, including macrophages, antigen-specific CD8+ cytotoxic T cells, and PBMCs. It induces the expression of CC chemokines such as MIP-1α and RANTES, which are responsible for the chemotactic movement and migration of immune cells at the site of infection to neutralize foreign particles in vivo and in vitro in several cell lines but their effect on tumor-associated macrophages is still not known. These cytokines are also known to influence the movement of several immune cells, including CD8+ cytotoxic T cells, toward inflammatory sites. Therefore, the effect of tumor-derived autologous Hsp70 on the expression of MIP-lα and RANTES in tumor-associated macrophages (TAMs) was investigated. Our results indicated that Hsp70 treatment-induced MIP-lα and RANTES expression was significantly greater in TAMs than in NMOs. According to the literature, the CC chemokine shares the same receptor, CCR5, as HIV does for their action, and therefore could provide better completion to the virus for ligand binding. Furthermore, Hsp70-preactivated TAMs induced increased IL-2 and IFN-γ expression in T cells during coculture for 48 h and upregulated the antitumor immune response of the host. Therefore, the outcome of our study could be useful for developing a better approach to restricting the growth and progression of tumors.

Correlation of High-Grade Osteosarcoma Response to Chemotherapy with Enhanced Tissue Immunological Response: Analysis of CD95R, IFN-γ, Catalase, Hsp70, and VEGF

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions.

Polydopamine-encapsulated zinc peroxide nanoparticles to target the metabolism-redox circuit against tumor adaptability for mild photothermal therapy

Regulating the metabolism-redox circuit of cancer cells has emerged as an attractive strategy to improve the therapeutic outcome, while often confronting the glaring issue of resistance due to the multiple adaptive responses of tumor cells. This study presents a simple yet efficient approach to regulate this circuit simultaneously against tumor adaptability by utilizing polydopamine-encapsulated zinc peroxide nanoparticles (ZnO2@PDA NPs). The nanoparticles could deliver large amounts of Zn2+ and H2O2 into tumor cells to unfold an intracellular self-amplifying loop for breaking the balance in zinc and redox homeostasis by H2O2-mediated endogenous Zn2+ release from metallothioneins due to its oxidation by H2O2 and Zn2+-induced in situ H2O2 production by disturbing mitochondrial respiration, ultimately disrupting tumor adaptability to exogenous stimuli. The elevated levels of Zn2+ and H2O2 also inhibited adenosine triphosphate (ATP) generation from glycolysis and mitochondrial respiration to disrupt energy adaptability. Furthermore, insufficient ATP supply could reduce glutathione and heat shock protein expression, thereby sensitizing oxidative stress and enabling PDA-mediated mild photothermal therapy (PTT). Consequently, this trinity nanoplatform, which integrated dual-starvation therapy, amplified oxidative stress, and mild PTT, demonstrated outstanding therapeutic effects and a facile strategy.

Dendritic cell-derived exosome (DEX) therapy for digestive system cancers: Recent advances and future prospect

Tumor-mediated immunosuppression is a fundamental obstacle to the development of dendritic cell (DC)-based cancer vaccines, which despite their ability to stimulate host anti-tumor CD8 T cell immunity, have not been able to generate meaningful therapeutic responses. Exosomes are inactive membrane vesicles that are nanoscale in size and are produced by the endocytic pathway. They are essential for intercellular communication. Additionally, DC-derived exosomes (DEXs) contained MHC class I/II (MHCI/II), which is frequently complexed with antigens and co-stimulatory molecules and is therefore able to prime CD4 and CD8 T cells that are specific to particular antigens. Indeed, vaccines with DEXs have been shown to exhibit better anti-tumor efficacy in eradicating tumors compared to DC vaccines in pre-clinical models of digestive system tumors. Also, there is room for improvement in the tumor antigenic peptide (TAA) selection process. DCs release highly targeted exosomes when the right antigenic peptide is chosen, which could aid in the creation of DEX-based antitumor vaccines that elicit more targeted immune responses. Coupled with their resistance to tumor immunosuppression, DEXs-based cancer vaccines have been heralded as the superior alternative cell-free therapeutic vaccines over DC vaccines to treat digestive system tumors. In this review, current studies of DEXs cancer vaccines as well as potential future directions will be deliberated.

Effects of isorhamnetin on liver injury in heat stroke-affected rats under dry-heat environments via oxidative stress and inflammatory response

Isorhamnetin is a natural flavonoid compound, rich in brass, alkaloids, and sterols with a high medicinal value. This study investigated the effects of isorhamnetin on liver injury and oxidative and inflammatory responses in heat-stroke-affected rats in a dry-heat environment. Fifty Sprague Dawley rats were randomly divided into five groups: normal temperature control (NC, saline), dry-heat control (DHC, saline), low-dose isorhamnetin-pretreated (L-AS, 25 mg/Kg), medium-dose isorhamnetin-pretreated (M-AS, 50 mg/Kg), and high-dose isorhamnetin-pretreated (H-AS, 100 mg/Kg) group. Saline was administered to the NC and DHC groups and corresponding concentrations of isorhamnetin were administered to the remaining three groups for 1 week. Blood and liver tissue were analyzed for oxidative stress and inflammation. The liver histopathological injury score, serum liver enzyme (alanine transaminase, aspartate transaminase, and lactate dehydrogenase), liver oxidative stress index (superoxide dismutase [SOD], catalase [CAT], and malondialdehyde), and inflammation index (tumor necrosis factor α [TNF-α], interleukin [IL]-1β, IL-6, and lipopolysaccharides) were significantly higher in the DHC group than in the NC group (P < 0.05). These index values in the L-AS, M-AS, and H-AS groups were significantly lower than those in the DHC group (P < 0.05). The index values decreased significantly with an increase in the concentration of isorhamnetin (P < 0.05), while the index values of CAT and SOD showed the opposite tendency (P < 0.05). The expression of liver tissue nuclear factor kappa B (NF-κB), caspase-3, and heat shock protein (HSP-70) was higher in the DHC group than in the NC group (P < 0.05). Comparison between the isorhamnetin and DHC groups revealed that the expression of NF-кB and caspase-3 was decreased, while that of HSP-70 continued to increase (P < 0.05). The difference was significant for HSP-70 among all the isorhamnetin groups (P < 0.05); however, the NF-кB and caspase-3 values in the L-AS and H-AS groups did not differ. In summary, isorhamnetin has protective effects against liver injury in heat-stroke-affected rats. This protective effect may be related to its activities concerning antioxidative stress, anti-inflammatory response, inhibition of NF-кB and caspase-3 expression, and enhancement of HSP-70 expression.

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.

Biomarkers in Adult-Type Diffuse Gliomas: Elevated Levels of Circulating Vesicular Heat Shock Protein 70 Serve as a Biomarker in Grade 4 Glioblastoma and Increase NK Cell Frequencies in Grade 3 Glioma

The presence of circulating Hsp70 levels and their influence on the immunophenotype of circulating lymphocyte subsets were examined as diagnostic/prognostic biomarkers for the overall survival (OS) in patients with IDH-mutant WHO grade 3 oligodendroglioma, astrocytoma, and IDH-wildtype grade 4 glioblastoma (GBM). Vesicular and free Hsp70 in the plasma/serum was measured using the Hsp70-exo and R&D Systems DuoSet® Hsp70 ELISAs. The immunophenotype and membrane Hsp70 status was determined by multiparameter flow cytometry on peripheral blood lymphocytes and single-cell suspensions of tumor specimens and cultured cells. Compared to healthy controls, circulating vesicular Hsp70 levels were significantly increased in patients with GBM, concomitant with a significant decrease in the proportion of CD3+/CD4+ helper T cells, whereas the frequency of NK cells was most prominently increased in patients with grade 3 gliomas. Elevated circulating Hsp70 levels and a higher prevalence of activated CD3-/CD56+/CD94+/CD69+ NK cells were associated with an improved OS in grade 3 gliomas, whereas high Hsp70 levels and low CD3+/CD4+ frequencies were associated with an adverse OS in GBM. It is assumed that a reduced membrane Hsp70 density on grade 4 versus grade 3 primary glioma cells and reduced CD3+/CD4+ T cell counts in GBM might drive an immunosuppressive tumor microenvironment.

High spatial-resolved heat manipulating membrane heterogeneity alters cellular migration and signaling

Plasma membrane heterogeneity is a key biophysical regulatory principle of membrane protein dynamics, which further influences downstream signal transduction. Although extensive biophysical and cell biology studies have proven membrane heterogeneity is essential to cell fate, the direct link between membrane heterogeneity regulation to cellular function remains unclear. Heterogeneous structures on plasma membranes, such as lipid rafts, are transiently assembled, thus hard to study via regular techniques. Indeed, it is nearly impossible to perturb membrane heterogeneity without changing plasma membrane compositions. In this study, we developed a high-spatial resolved DNA-origami-based nanoheater system with specific lipid heterogeneity targeting to manipulate the local lipid environmental temperature under near-infrared (NIR) laser illumination. Our results showed that the targeted heating of the local lipid environment influences the membrane thermodynamic properties, which further triggers an integrin-associated cell migration change. Therefore, the nanoheater system was further applied as an optimized therapeutic agent for wound healing. Our strategy provides a powerful tool to dynamically manipulate membrane heterogeneity and has the potential to explore cellular function through changes in plasma membrane biophysical properties.

A single photodynamic priming protocol augments delivery of ⍺-PD-L1 mAbs and induces immunogenic cell death in head and neck tumors

Photodynamic priming (PDP) leverages the photobiological effects of subtherapeutic photodynamic therapy (PDT) regimens to modulate the tumor vasculature and stroma. PDP also sensitizes tumors to secondary therapies, such as immunotherapy by inducing a cascade of molecular events, including immunogenic cell death (ICD). We and others have shown that PDP improves the delivery of antibodies, among other theranostic agents. However, it is not known whether a single PDP protocol is capable of both inducing ICD in vivo and augmenting the delivery of immune checkpoint inhibitors. In this rapid communication, we show for the first time that a single PDP protocol using liposomal benzoporphyrin derivative (Lipo-BPD, 0.25 mg/kg) with 690 nm light (75 J/cm2 , 100 mW/cm2 ) simultaneously doubles the delivery of ⍺-PD-L1 antibodies in murine AT-84 head and neck tumors and induces ICD in vivo. ICD was observed as a 3-11 fold increase in tumor cell exposure of damage-associated molecular patterns (Calreticulin, HMGB1, and HSP70). These findings suggest that this single, highly translatable PDP protocol using clinically relevant Lipo-BPD holds potential for improving immunotherapy outcomes in head and neck cancer. It can do so by simultaneously overcoming physical barriers to the delivery of immune checkpoint inhibitors, and biochemical barriers that contribute to immunosuppression.

Hsp70-Targeting and Size-Tunable Nanoparticles Combine with PD-1 Checkpoint Blockade to Treat Glioma

Invasive glioma usually disrupts the integrity of the blood-brain barrier (BBB), making the delivery of nanodrugs across the BBB possible, but sufficient targeting ability is still avidly needed to improve drug accumulation in glioma. Membrane-bound heat shock protein 70 (Hsp70) is expressed on the membrane of glioma cells rather than adjacent normal cells, therefore it can serve as a specific glioma target. Meanwhile, prolonging the retention in tumors is important for active-targeting nanoparticles to overcome receptor-binding barriers. Herein, the Hsp70-targeting and acid-triggered self-assembled gold nanoparticles (D-A-DA/TPP) are proposed to realize selective delivery of doxorubicin (DOX) to glioma. In the weakly acidic glioma matrix, D-A-DA/TPP formed aggregates to prolong retention, improve receptor-binding efficiency and facilitate acid-responsive DOX release. DOX accumulation in glioma induced immunogenic cell death (ICD) to promote antigen presentation. Meanwhile, combination with the PD-1 checkpoint blockade further activate T cells and provokes robust anti-tumor immunity. The results showed that D-A-DA/TPP can induce more glioma apoptosis. Furthermore, in vivo studies indicated D-A-DA/TPP plus PD-1 checkpoint blockade significantly improved median survival time. This study offeres a potential nanocarrier combining size-tunable strategy with active targeting ability to increase drug enrichment in glioma and synergizes with PD-1 checkpoint blockade to achieve chemo-immunotherapy.

Revealing the Effect of Photothermal Therapy on Human Breast Cancer Cells: A Combined Study from Mechanical Properties to Membrane HSP70

Hyperthermia-induced overexpression of heat shock protein 70 (HSP70) leads to the thermoresistance of cancer cells and reduces the efficiency of photothermal therapy (PTT). In contrast, cancer cell-specific membrane-associated HSP70 has been proven to activate antitumor immune responses. The dual effect of HSP70 on cancer cells inspires us that in-depth research of membrane HSP70 (mHSP70) during PTT treatment is essential. In this work, a PTT treatment platform for human breast cancer cells (MCF-7 cells) based on a mPEG-NH₂-modified polydopamine (PDA)-coated gold nanorod core-shell structure (GNR@PDA-PEG) is developed. Using the force-distance curve-based atomic force microscopy (FD-based AFM), we gain insight into the PTT-induced changes in the morphology, mechanical properties, and mHSP70 expression and distribution of individual MCF-7 cells with high-resolution at the single-cell level. PTT treatment causes pseudopod contraction of MCF-7 cells and generates a high level of intracellular reactive oxygen species, which severely disrupt the cytoskeleton, leading to a decrease in cellular mechanical properties. The adhesion maps, which are recorded by aptamer A8 functional probes using FD-based AFM, reveal that PTT treatment causes a significant upregulation of mHSP70 expression and it starts to exhibit a partial aggregation distribution on the MCF-7 cell surface. This work not only exemplifies that AFM can be a powerful tool for detecting changes in cancer cells during PTT treatment but also provides a better view for targeting mHSP70 for cancer therapy.

Colorectal cancer-derived extracellular vesicles containing HSP70 enhance macrophage phagocytosis by up-regulating MARCO expression

In recent years, we have realized that extracellular vesicles (EVs) play a critical role in regulating the intercellular communication between tumor and immune cells in the tumor microenvironment (TME). Tumor-derived extracellular vesicles (TDEVs) profoundly affect the functional changes of tumor-associated macrophages (TAMs) and promote their M2 polarization. Meanwhile, macrophages have a strong phagocytic ability in phagocytosing apoptotic cells. Especially in the course of chemotherapy or radiotherapy, TAMs can phagocytose and remove apoptotic tumor cells, showing anti-inflammatory and pro-tumor effects. However, the underlying mechanisms by which TDEVs regulate macrophage phagocytosis of apoptotic tumor cells have not been fully elucidated. In this study, we focused on the effect of colorectal cancer-derived extracellular vesicles (CRC-EVs) on macrophages. We demonstrated that CRC-EVs enhanced macrophage phagocytosis of apoptotic CRC cells. We then determined that heat shock protein 70 (HSP70) carried in CRC-EVs was responsible for this effect by using mass spectrometry-based proteomic analysis and the CRISPR-Cas9 system. Through transcriptome sequencing of macrophages, we found that the enhanced phagocytosis of macrophages was mainly due to the up-regulation of the macrophage receptor with collagenous structure (MARCO). In addition, we confirmed that the up-regulation of MARCO was mediated by the AKT-STAT3 signaling pathway. Taken together, this study revealed a novel EVs-mediated macrophage phagocytosis mechanism involved in the clearance of apoptotic tumor cells in TME. Targeting TDEVs may have potential therapeutic applications in tumor treatment.

Extracellular vesicles production and proteomic cargo varies with incubation time and temperature

Extracellular vesicles (EVs) are heterogenous populations of proteolipid bi-layered vesicles secreted by cells as an important biological process. EVs cargo can reflect the cellular environmental conditions in which cells grow. The use of serum-free conditioned media to harvest EVs leads to stress-mediated cellular changes with longer incubation time and impacts EV production and functionality. This study aims to explore the role of incubation time and temperature on EV production and proteomic cargo. For this purpose, an optimized ultrafiltration-size exclusion chromatography-based technique is developed, which isolates small EVs ranging from 130 to 220 nm. The result shows higher EVs production in cancerous cells (K7M2) compared to noncancerous cells (NIH/3T3), which increases with longer incubation time and elevated temperature. Mass spectrometry-based proteomic characterization of EVs showed incubation time and temperature-dependent proteomic profile. A set of enriched EV proteins were identified in EVs isolated at nutrient-stress (72 h incubation time) and heat-stress (40 °C incubation temperature) environment. Enrichment of Serpinb1a in EVs isolated in heat stress was further validated via immunoblot. Gene enrichment analysis revealed that enriched EV proteins following nutrient stress were involved in negative regulation of transcription, response to oxidative stress, and protein folding. Likewise, enriched EV proteins following heat stress were involved in oxaloacetate and aspartate metabolism, and glutamate catabolic process. EVs isolated under nutrient stress showed pro-proliferative activity whereas EVs isolated under heat stress showed anti-proliferative activity. Our results show that incubation time and temperature can alter EV production, its proteomic cargo, and functionality, which can be used to design need-based standard isolation parameters for reproducible EV research.

Preclinical evaluation of oncolytic potential human rotavirus Wt 1-5 in gastric adenocarcinoma

Despite advances in biomedical research, gastric cancer remains the leading cause of morbidity and mortality worldwide due to the limited efficacy of conventional therapies. In recent decades, oncolytic viruses have emerged as a biological therapeutic alternative to cancer due to their selectivity, effectiveness, and low toxicity. However, clinical trials have shown that developing a virus with selectivity for multiple tumor receptors and the ability to penetrate and diffuse through the tumor microenvironment to reactivate the immune system remains challenging. This study aimed to examine the oncolytic potential of tumor cell-adapted rotavirus Wt1-5 in gastric adenocarcinoma samples. This study focused on determining the propagation capacity of the RV Wt1-5 through the tumor and the importance of the expression of cell surface co-receptors, including integrin β3, protein disulfide isomerase (PDI), and heat shock proteins (Hsp-90, -70, -60, -40, and Hsc 70), during infection of tumor cells. These proteins were found to be differentially expressed in tumor cells compared to adjacent non-tumor cells. Preincubation of gastric tumor cells with antibodies against these proteins decreased rotavirus infections, validating their importance in the binding and entry of RV Wt1-5 into tumor cells, as previously reported. Upon RV infection, apoptosis was one of the types of death that was observed. This was evidenced by evaluating the expression of CASP-3, -9, PARP, cytochrome C, Bax, Bid, p53, and Bcl-2, as well as observing morphological changes such as chromatin margination, nuclear condensation, and fragmentation. Finally, at 60 h.p.i, histological analysis revealed that oncolysis compromised the entire thickness of the tumor. Therefore, the results suggest that RV Wt1-5 could be a novel therapeutic agent co-adjuvant agent for conventional and targeted therapies in managing GC. Ex vivo infection of the tumor tissue model showed characteristics of an immune response that could be explored in future studies.

Recent advances in nanotechnology approaches for non-viral gene therapy

Gene therapy has shown great potential in the treatment of many diseases by downregulating the expression of certain genes. The development of gene vectors as a vehicle for gene therapy has greatly facilitated the widespread clinical application of nucleic acid materials (DNA, mRNA, siRNA, and miRNA). Currently, both viral and non-viral vectors are used as delivery systems of nucleic acid materials for gene therapy. However, viral vector-based gene therapy has several limitations, including immunogenicity and carcinogenesis caused by the exogenous viral vectors. To address these issues, non-viral nanocarrier-based gene therapy has been explored for superior performance with enhanced gene stability, high treatment efficiency, improved tumor-targeting, and better biocompatibility. In this review, we discuss various non-viral vector-mediated gene therapy approaches using multifunctional biodegradable or non-biodegradable nanocarriers, including polymer-based nanoparticles, lipid-based nanoparticles, carbon nanotubes, gold nanoparticles (AuNPs), quantum dots (QDs), silica nanoparticles, metal-based nanoparticles and two-dimensional nanocarriers. Various strategies to construct non-viral nanocarriers based on their delivery efficiency of targeted genes will be introduced. Subsequently, we discuss the cellular uptake pathways of non-viral nanocarriers. In addition, multifunctional gene therapy based on non-viral nanocarriers is summarized, in which the gene therapy can be combined with other treatments, such as photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy and chemotherapy. We also provide a comprehensive discussion of the biological toxicity and safety of non-viral vector-based gene therapy. Finally, the present limitations and challenges of non-viral nanocarriers for gene therapy in future clinical research are discussed, to promote wider clinical applications of non-viral vector-based gene therapy.

Multi-Layered PLGA-PEI Nanoparticles Functionalized with TKD Peptide for Targeted Delivery of Pep5 to Breast Tumor Cells and Spheroids

PURPOSE

Peptide-based therapy is a promising strategy for cancer treatment because of its low drug resistance. However, the major challenge is their inability to target cancer cells specifically. So, a targeted nano-delivery system that could deliver therapeutic peptides selectively to cancer cells to stimulate their action is highly desirable. This study aims to deliver the antitumor peptide, Pep5, to breast tumor cells selectively using a targeting peptide functionalised multi-layered PLGA-PEI nanoparticles.

METHODS

In this study, Pep5 entrapped PLGA-PEI (Pep5-PPN) dual layered nanoparticles were developed. These nanoparticles were decorated with TKD (Pep5-TPPN) on their surface for site-specific delivery of Pep5 to breast tumor cells. The particles were then characterized using various instrumental analyses. In vitro cytotoxicity of the particles was evaluated in estrogen receptor positive (ER+ve) and triple negative breast cancer (TNBC) cells. An ex vivo tumor spheroid model was used to analyze the antitumor activity of the particles.

RESULTS

Uniformly round Pep5-TPPN particles were synthesized with an average diameter of 420.8 ± 14.72 nm. The conjugation of PEI over Pep5-PLGA nanoparticles shifted the zeta potential from -11.6 ± 2.16 mV to +20.01 ± 2.97 mV. In vitro cytotoxicity analysis proved that TKD conjugation to nanoparticles enhanced the antitumor activity of Pep5 in tested breast cancer cells. Pep5-TPPN induced cytoskeletal damage and apoptosis in the tested cells, which showed that the mechanism of action of Pep5 is conserved but potentiated. Active targeting of Pep5 suppressed the tumor growth in ex vivo spheroid models.

CONCLUSION

A multi-layered nanoparticle functionalized with dual peptide was fabricated for active tumor targeting, which stimulated Pep5 activity to reduce the tumor growth in vitro and ex vivo.

Terminalia chebula Polyphenol and Near-Infrared Dye-Loaded Poly(lactic acid) Nanoparticles for Imaging and Photothermal Therapy of Cancer Cells

Photothermal/photodynamic therapies (PTT/PDT) are multimodal approaches employing near-infrared (NIR) light-responsive photosensitizers for cancer treatment. In the current study, IR-775, a hydrophobic photosensitizer, was used in combination with a polyphenols (p)-rich ethyl acetate extract from Terminalia chebula to treat cancer. IR-775 dye and polyphenols were encapsulated in a poly(lactic acid) polymeric nanosystem (PpIR NPs) to increase the cell bioavailability. The hydrodynamic diameter of PpIR NPs is 142.6 ± 2 nm and exhibited physical stability. The nanosystem showed enhanced cellular uptake in a lung cancer cell line (A549). Cell cytotoxicity results indicate that PpIR NPs showed more than 82.46 ± 3% cell death upon NIR light treatment compared to the control groups. Both PDT and PTT generate reactive oxygen species (ROS) and cause hyperthermia, thereby enhancing cancer cell death. Qualitative and quantitative analyses have depicted that PpIR NPs with NIR light irradiation have decreased protein expression of HSP70 and PARP, and increased γ-H2AX, which collectively lead to cell death. After NIR light irradiation, the relative gene expression patterns of HSP70 and CDK2Na were also downregulated. Further, PpIR NPs uptake has been studied in 3D cells and in ovo bioimaging in zebrafish models. In conclusion, the PpIR NPs show good cancer cell cytotoxicity and present a potential nanosystem for bioimaging.

Nanomaterial-mediated low-temperature photothermal therapy via heat shock protein inhibition

With the continuous development of nanobiotechnology in recent years, combining photothermal materials with nanotechnology for tumor photothermal therapy (PTT) has drawn many attentions nanomedicine research. Although nanomaterial-mediated PTT is more specific and targeted than traditional treatment modalities, hyperthermia can also damage normal cells. Therefore, researchers have proposed the concept of low-temperature PTT, in which the expression of heat shock proteins (HSPs) is inhibited. In this article, the research strategies proposed in recent years based on the inhibition of HSPs expression to achieve low-temperature PTT was reviewed. Folowing this, the synthesis, properties, and applications of these nanomaterials were introduced. In addition, we also summarized the problems of nanomaterial-mediated low-temperature PTT at this stage and provided an outlook on future research directions.

HSP70 protects H9C2 cells from hypoxia and reoxygenation injury through STIM1/IP3R

Hypoxia/reoxygenation (H/R) is used as an in vivo model of ischemia/reperfusion injury, and myocardial ischemia can lead to heart disease. Calcium overload is an important factor in myocardial ischemia-reperfusion injury and can lead to apoptosis of myocardial cells. Therefore, it is of great clinical importance to find ways to regulate calcium overload and reduce apoptosis of myocardial cells, and thus alleviate myocardial ischemia-reperfusion injury. There is evidence that heat shock protein 70 (HSP70) has a protective effect on the myocardium, but the exact mechanism of this effect is not completely understood. Stromal interaction molecule 1 and inositol 1,4,5-triphosphate receptor (STIM/1IP3R) play an important role in myocardial ischemia-reperfusion injury. Therefore, this study aimed to investigate whether HSP70 plays an anti-apoptotic role in H9C2 cardiomyocytes by regulating the calcium overload pathway through STIM1/IP3R. Rat H9C2 cells were subjected to transient oxygen and glucose deprivation (incubated in glucose-free medium and hypoxia for 6 h) followed by re-exposure to glucose and reoxygenation (incubated in high glucose medium and reoxygenation for 4 h) to simulate myocardial ischemia reperfusion-induced cell injury. H9C2 cell viability was significantly decreased, and lactate dehydrogenase (LDH) release and apoptosis were significantly increased after oxygen and glucose deprivation. Transfection of HSP70 into H9C2 cells could reduce the corresponding effect, increase cell viability and anti-apoptotic signal pathway, and reduce the apoptotic rate and pro-apoptotic signal pathway. After hypoxia and reoxygenation, the expression of STIM1/IP3R and intracellular calcium concentration of HSP70-overexpressed H9C2 cells were significantly lower than those of hypoxia cells. Similarly, direct silencing of STIM1 by siRNA significantly increased cell viability and expression of anti-apoptotic protein Bcl-2 and decreased apoptosis rate and expression of pro-apoptotic protein BAX. These data are consistent with HSP70 overexpression. These results suggest that HSP70 abrogates intracellular calcium overload by inhibiting upregulation of STIM1/IP3R expression, thus reducing apoptosis in H9C2 cells and playing a protective role in cardiomyocytes.

Tumour Derived Extracellular Vesicles: Challenging Target to Blunt Tumour Immune Evasion

Simple Summary

Tumour onset and development occur because of specific immune support. The immune system, which is originally able to perceive and eliminate incipient cancer cells, becomes suppressed and hijacked by cancer. For these purposes, tumour cells use extracellular vesicles (TEVs). Specific molecular composition allows TEVs to reprogram immune cells towards tumour tolerance. Circulating TEVs move from their site of origin to other organs, preparing “a fertile soil” for metastasis formation. This implies that TEV molecular content can provide a valuable tool for cancer biomarker discovery and potential targets to reshape the immune system into tumour recognition and eradication.

Abstract

Control of the immune response is crucial for tumour onset and progression. Tumour cells handle the immune reaction by means of secreted factors and extracellular vesicles (EV). Tumour-derived extracellular vesicles (TEV) play key roles in immune reprogramming by delivering their cargo to different immune cells. Tumour-surrounding tissues also contribute to tumour immune editing and evasion, tumour progression, and drug resistance via locally released TEV. Moreover, the increase in circulating TEV has suggested their underpinning role in tumour dissemination. This review brings together data referring to TEV-driven immune regulation and antitumour immune suppression. Attention was also dedicated to TEV-mediated drug resistance.

Combined Cytotoxic Effect of Inhibitors of Proteostasis on Human Colon Cancer Cells

Despite significant progress in the diagnosis and treatment of colorectal cancer, drug resistance continues to be a major limitation of therapy. In this regard, studies aimed at creating combination therapy are gaining popularity. One of the most promising adjuvants are inhibitors of the proteostasis system, chaperone machinery, and autophagy. The main HSP regulator, HSF1, is overactivated in cancer cells and autophagy sustains the survival of malignant cells. In this work, we focused on the selection of combination therapy for the treatment of rectal cancer cells obtained from patients after tumor biopsy without prior treatment. We characterized the migration, proliferation, and chaperone status in the resulting lines and also found them to be resistant to a number of drugs widely used in the clinic. However, these cells were sensitive to the autophagy inhibitor, chloroquine. For combination therapy, we used an HSF1 activity inhibitor discovered earlier in our laboratory, the cardenolide CL-43, which has already been proven as an auxiliary component of combined therapy in established cell lines. CL-43 effectively suppressed HSF1 activity and Hsp70 expression in all investigated cells. We tested the autophagy inhibitor, chloroquine, in combination with CL-43. Our results indicate that the use of an inhibitor of HSF1 activity in combination with an autophagy inhibitor results in effective cancer cell death, therefore, this therapeutic approach may be a promising treatment regimen for certain patients.

Phosphatidylinositol Monophosphates Regulate the Membrane Localization of HSPA1A, a Stress-Inducible 70-kDa Heat Shock Protein

HSPA1A is a molecular chaperone that regulates the survival of stressed and cancer cells. In addition to its cytosolic pro-survival functions, HSPA1A also localizes and embeds in the plasma membrane (PM) of stressed and tumor cells. Membrane-associated HSPA1A exerts immunomodulatory functions and renders tumors resistant to standard therapies. Therefore, understanding and manipulating HSPA1A's surface presentation is a promising therapeutic. However, HSPA1A's pathway to the cell surface remains enigmatic because this protein lacks known membrane localization signals. Considering that HSPA1A binds to lipids, like phosphatidylserine (PS) and monophosphorylated phosphoinositides (PIPs), we hypothesized that this interaction regulates HSPA1A's PM localization and anchorage. To test this hypothesis, we subjected human cell lines to heat shock, depleted specific lipid targets, and quantified HSPA1A's PM localization using confocal microscopy and cell surface biotinylation. These experiments revealed that co-transfection of HSPA1A with lipid-biosensors masking PI(4)P and PI(3)P significantly reduced HSPA1A's heat-induced surface presentation. Next, we manipulated the cellular lipid content using ionomycin, phenyl arsine oxide (PAO), GSK-A1, and wortmannin. These experiments revealed that HSPA1A's PM localization was unaffected by ionomycin but was significantly reduced by PAO, GSK-A1, and wortmannin, corroborating the findings obtained by the co-transfection experiments. We verified these results by selectively depleting PI(4)P and PI(4,5)P₂ using a rapamycin-induced phosphatase system. Our findings strongly support the notion that HSPA1A's surface presentation is a multifaceted lipid-driven phenomenon controlled by the binding of the chaperone to specific endosomal and PM lipids.

Tumor-targeted/reduction-triggered composite multifunctional nanoparticles for breast cancer chemo-photothermal combinational therapy

Breast cancer has become the most commonly diagnosed cancer type in the world. A combination of chemotherapy and photothermal therapy (PTT) has emerged as a promising strategy for breast cancer therapy. However, the intricacy of precise delivery and the ability to initiate drug release in specific tumor sites remains a challenging puzzle. Therefore, to ensure that the therapeutic agents are synchronously delivered to the tumor site for their synergistic effect, a multifunctional nanoparticle system (PCRHNs) is developed, which is grafted onto the prussian blue nanoparticles (PB NPs) by reduction-responsive camptothecin (CPT) prodrug copolymer, and then modified with tumor-targeting peptide cyclo(Asp-d-Phe-Lys-Arg-Gly) (cRGD) and hyaluronic acid (HA). PCRHNs exhibited nano-sized structure with good monodispersity, high load efficiency of CPT, triggered CPT release in response to reduction environment, and excellent photothermal conversion under laser irradiation. Furthermore, PCRHNs can act as a photoacoustic imaging contrast agent-guided PTT. In vivo studies indicate that PCRHNs exhibited excellent biocompatibility, prolonged blood circulation, enhanced tumor accumulation, allow tumor-specific chemo-photothermal therapy to achieve synergistic antitumor effects with reduced systemic toxicity. Moreover, hyperthermia-induced upregulation of heat shock protein 70 in the tumor cells could be inhibited by CPT. Collectively, PCRHNs may be a promising therapeutic way for breast cancer therapy.

Microparticles: biogenesis, characteristics and intervention therapy for cancers in preclinical and clinical research

Extracellular vesicles (EVs), spherical biological vesicles, mainly contain nucleic acids, proteins, lipids and metabolites for biological information transfer between cells. Microparticles (MPs), a subtype of EVs, directly emerge from plasma membranes, and have gained interest in recent years. Specific cell stimulation conditions, such as ultraviolet and X-rays irradiation, can induce the release of MPs, which are endowed with unique antitumor functionalities, either for therapeutic vaccines or as direct antitumor agents. Moreover, the size of MPs (100–1000 nm) and their spherical structures surrounded by a lipid bilayer membrane allow MPs to function as delivery vectors for bioactive antitumor compounds, with favorable phamacokinetic behavior, immunostimulatory activity and biological function, without inherent carrier-specific toxic side effects. In this review, the mechanisms underlying MP biogenesis, factors that influence MP production, properties of MP membranes, size, composition and isolation methods of MPs are discussed. Additionally, the applications and mechanisms of action of MPs, as well as the main hurdles for their applications in cancer management, are introduced.

Acute lymphoblastic leukemia-derived extracellular vesicles affect quiescence of hematopoietic stem and progenitor cells

Patient-derived xenografted (PDX) models were generated through the transplantation of primary acute lymphoblastic leukemia (ALL) cells into immunodeficient NSG mice. We observed that ALL cells from mouse bone marrow (BM) produced extracellular vesicles (EVs) with specific expression of inducible heat shock protein HSP70, which is commonly activated in cancer cells. Taking advantage of this specific expression, we designed a strategy to generate fluorescent HSP70-labeled ALL EVs and monitor the impact of these EVs on endogenous murine BM cells ex vivo and in vivo. We discovered that hematopoietic stem and progenitor cells (HSPC) were mainly targeted by ALL EVs, affecting their quiescence and maintenance in the murine BM environment. Investigations revealed that ALL EVs were enriched in cholesterol and other metabolites that contribute to promote the mitochondrial function in targeted HSPC. Furthermore, using CD34⁺ cells isolated from cord blood, we confirmed that ALL EVs can modify quiescence of human HSPC. In conclusion, we have discovered a new oncogenic mechanism illustrating how EVs produced by proliferative ALL cells can target and compromise a healthy hematopoiesis system during leukemia development.

Sublethal heat treatment promotes breast cancer metastasis and its molecular mechanism revealed by quantitative proteomic analysis

Radiofrequency ablation (RFA) is a frequently used thermal ablation technique for breast tumors. The study aimed to identify the effect of sublethal heat treatment on biological function of breast cancer cells and reveal its potential molecular mechanism. The expression profile of dysregulated proteins in sublethal heat treated breast cancer cells was analyzed by quantitative proteomic analysis. The differentially expressed proteins in the sublethal heat treated breast cancer were identified. The potential biological functions of these proteins were evaluated. The proliferation and invasion ability of breast cancer cells were enhanced after sublethal heat treatment. The expression profile of proteins in sublethal heat treated breast cancer cells was abundant, and most of which were newly discovered. A total of 206 differentially expressed proteins were identified. Among them, 101 proteins were downregulated while 105 proteins were upregulated. GO and KEGG analysis indicated that various systems were involved in the process of sublethal heat treatment including cancer, immune system, et al. Immunohistochemistry staining showed that the expression of Heat shock protein 1B, NOB1 and CRIP1 was highly expressed while the expression of BCLAF1 was lower in sublethal heat treated group. The proliferation and invasion ability of breast cancer cells were enhanced after sublethal heat treatment. Sublethal heat treatment caused gene alterations in cancer and immune system. Heat shock protein 1B, NOB1 and CRIP1 were upregulated while BCLAF1 was downregulated in breast cancer after sublethal heat treatment.

Sensitive and rapid determination of heat shock protein 70 using lateral flow immunostrips and upconversion nanoparticle fluorescence probes

Heat shock protein 70 (Hsp70), belonging to the heat shock protein (HSP) family, is reported to be a potential diagnostic biomarker.

Osteosarcoma exocytosis of soluble LGALS3BP mediates macrophages toward a tumoricidal phenotype

This study aimed to elucidate the interactions between osteosarcoma (OS) and M1 macrophages infiltrated into the tumor microenvironment and to explore the underlying mechanisms whereby M1 macrophages influence the growth of OS, so that novel treatments of OS can be developed. A transwell co-culture system, an indirect conditioned medium culture system and two orthotopic bearing OS models were established to assess for the interplay between M1 macrophages and OS. We found that the co-culture of M1 macrophages with OS cells significantly inhibited the growth of the tumor cells by inducing apoptosis. Furthermore, HSPA1L secreted by M1 macrophages exerted this anti-tumor effect through the IRAK1 and IRAK4 pathways. LGALS3BP secreted by OS cells bound to the ligand LGALS3 on M1 macrophages and thereby induced the secretion of Hspa11 via Akt phosphorylation. In vivo experiments demonstrated that the culture supernatant of OS-stimulated M1 macrophages significantly inhibited the growth of OS, whereas silencing Lgals3bp promoted the progression of OS. In conclusion, OS modifies the phenotype of tumor-associated macrophages (TAMs) and thereby influences the apoptosis of OS cells through soluble factors. The modulation of TAMs may be a promising and effective therapeutic approach in OS.

The HSP Immune Network in Cancer

Heat shock proteins are molecular chaperones which support tumor development by regulating various cellular processes including unfolded protein response, mitochondrial bioenergetics, apoptosis, autophagy, necroptosis, lipid metabolism, angiogenesis, cancer cell stemness, epithelial-mesenchymal transition and tumor immunity. Apart from their intracellular activities, HSPs have also distinct extracellular functions. However, the role that HSP chaperones play in the regulation of immune responses inside and outside the cell is not yet clear. Herein, we explore the intracellular and extracellular immunologic functions of HSPs in cancer. A broader understanding of how HSPs modulate immune responses may provide critical insights for the development of effective immunotherapies.

Incomplete radiofrequency ablation induced chemoresistance by up-regulating heat shock protein 70 in hepatocellular carcinoma

Radiofrequency ablation (RFA) is a common minimally invasive treatment for hepatocellular carcinoma (HCC). Incomplete RFA (iRFA) due to the sub-lethal heat shock challenge of some cell populations leads to the generation of transformed survivor cells with enhanced chemoresistance. However, the underlying mechanism of iRFA on HCCs chemoresistance remains unknown. In the present study, we investigated the effect of iRFA on HCCs sensitivity to cisplatin. Cells treated with the sub-lethal heat shock challenge were used to mimic iRFA treatment in vitro. An orthotopic implantation HCC model was established and also performed iRFA treatment. Flow cytometry, transwell assay, and cell counting kit-8 assay were used to determine the effect of iRFA treatment on cisplatin-induced HCC cell apoptosis, invasion, and cell viability. ELISA and Western blot were used to detect the effect of iRFA treatment on cisplatin-induced HCC cell pyroptosis. We found that iRFA treatment increased the HCC cell proliferation and invasion ability, and inhibited cisplatin-induced pyroptosis. Further experiments showed that iRFA treatment induced upregulation of HSP70, which inhibited the cisplatin-induced NLRP3 inflammasome activation, leading to inhibition of pyroptosis. HSP70 knockdown or NLRP3 overexpression could reverse the effect of iRFA treatment in vitro. In vivo, HSP70 knockdown reversed the chemosensitivity of HCC to cisplatin, which was decreased by iRFA. In conclusion, we demonstrated that iRFA induced drug resistance by HSP70-mediated inhibition of cell pyroptosis in HCC.

HSP70s in Breast Cancer: Promoters of Tumorigenesis and Potential Targets/Tools for Therapy

The high frequency of breast cancer worldwide and the high mortality among women with this malignancy are a serious challenge for modern medicine. A deeper understanding of the mechanisms of carcinogenesis and emergence of metastatic, therapy-resistant breast cancers would help development of novel approaches to better treatment of this disease. The review is dedicated to the role of members of the heat shock protein 70 subfamily (HSP70s or HSPA), mainly inducible HSP70, glucose-regulated protein 78 (GRP78 or HSPA5) and GRP75 (HSPA9 or mortalin), in the development and pathogenesis of breast cancer. Various HSP70-mediated cellular mechanisms and pathways which contribute to the oncogenic transformation of mammary gland epithelium are reviewed, as well as their role in the development of human breast carcinomas with invasive, metastatic traits along with the resistance to host immunity and conventional therapeutics. Additionally, intracellular and cell surface HSP70s are considered as potential targets for therapy or sensitization of breast cancer. We also discuss a clinical implication of Hsp70s and approaches to targeting breast cancer with gene vectors or nanoparticles downregulating HSP70s, natural or synthetic (small molecule) inhibitors of HSP70s, HSP70-binding antibodies, HSP70-derived peptides, and HSP70-based vaccines.

The abnormal level of HSP70 is related to Treg/Th17 imbalance in PCOS patients

BACKGROUND

Polycystic ovary syndrome (PCOS) is a disease with chronic nonspecific low-grade inflammation. The imbalance of immune cells exists in PCOS. Several studies have found that heat shock protein 70 (HSP70) may be involved in the immunological pathogenesis of PCOS, but the relationship between HSP70 and Regulatory T cell (Treg)/T helper cell 17(Th17) ratio remains unclear. This study aims to explore the correlation between HSP70 and Treg/Th17 ratio and to provide evidence for the role of HSP70 in the immunological etiology of PCOS.

RESULTS

There was no significant difference in age and body mass index (BMI) between the two groups. The concentrations of basal estradiol (E₂), basal follicle-stimulating hormone (FSH) did not show a significant difference between the two groups. The concentrations of basal luteinizing hormone (LH) (P < 0.01), testosterone (T) (P < 0.01), glucose (P < 0.001) and insulin (P < 0.001) in PCOS patients were significantly higher than those in the control group. The protein levels of HSP70 were significantly higher in serum in the PCOS group (P < 0.001). The percentage of Treg cells was significantly lower (P < 0.01), while the percentage of the Th17 cells of the PCOS group was significantly higher than that of the control group (P < 0.05). The ratio of Treg/Th17 in the PCOS group was significantly lower (P < 0.001). The concentrations of Interleukin (IL)-6, IL-17, and IL-23 were significantly higher, while the levels of IL-10 and Transforming growth factor-β (TGF-β) were significantly lower in the PCOS group (P < 0.001). Spearman rank correlation analysis showed a strong negative correlation of serum HSP70 levels with Treg/Th17 ratio, IL-10, and TGF-β levels. In contrast, HSP70 levels were significantly positively correlated with IL-6, IL-17, IL-23, LH, insulin, and glucose levels.

CONCLUSION

The abnormal level of HSP70 is correlated with Treg/Th17 imbalance and corresponding cytokines, which indicates that HSP70 may play an important role in PCOS immunologic pathogenesis.

Polyamine metabolism links gut microbiota and testicular dysfunction

BACKGROUND

Male fertility impaired by exogenous toxins is a serious worldwide issue threatening the health of the new-born and causing infertility. However, the metabolic connection between toxic exposures and testicular dysfunction remains unclear.

RESULTS

In the present study, the metabolic disorder of testicular dysfunction was investigated using triptolide-induced testicular injury in mice. We found that triptolide induced spermine deficiency resulting from disruption of polyamine biosynthesis and uptake in testis, and perturbation of the gut microbiota. Supplementation with exogenous spermine reversed triptolide-induced testicular dysfunction through increasing the expression of genes related to early and late spermatogenic events, as well as increasing the reduced number of offspring. Loss of gut microbiota by antibiotic treatment resulted in depletion of spermine levels in the intestine and potentiation of testicular injury. Testicular dysfunction in triptolide-treated mice was reversed by gut microbial transplantation from untreated mice and supplementation with polyamine-producing Parabacteroides distasonis. The protective effect of spermine during testicular injury was largely dependent on upregulation of heat shock protein 70s (HSP70s) both in vivo and in vitro.

CONCLUSIONS

The present study linked alterations in the gut microbiota to testicular dysfunction through disruption of polyamine metabolism. The diversity and dynamics of the gut microbiota may be considered as a therapeutic option to prevent male infertility. Video Abstract.

Targeting lysosomes in human disease: from basic research to clinical applications

In recent years, accumulating evidence has elucidated the role of lysosomes in dynamically regulating cellular and organismal homeostasis. Lysosomal changes and dysfunction have been correlated with the development of numerous diseases. In this review, we interpreted the key biological functions of lysosomes in four areas: cellular metabolism, cell proliferation and differentiation, immunity, and cell death. More importantly, we actively sought to determine the characteristic changes and dysfunction of lysosomes in cells affected by these diseases, the causes of these changes and dysfunction, and their significance to the development and treatment of human disease. Furthermore, we outlined currently available targeting strategies: (1) targeting lysosomal acidification; (2) targeting lysosomal cathepsins; (3) targeting lysosomal membrane permeability and integrity; (4) targeting lysosomal calcium signaling; (5) targeting mTOR signaling; and (6) emerging potential targeting strategies. Moreover, we systematically summarized the corresponding drugs and their application in clinical trials. By integrating basic research with clinical findings, we discussed the current opportunities and challenges of targeting lysosomes in human disease.

Similarities and Differences of Hsp70, hsc70, Grp78 and Mortalin as Cancer Biomarkers and Drug Targets

Background: Upregulation of Heath Shock Protein 70 (HSP70) chaperones supports cancer cell survival. Their high homology causes a challenge to differentiate them in experimental or prevention and treatment strategies. The objective of this investigation was to determine similarities and differences of Hsp70, hsc70, Grp78 and Mortalin members of the HSP70 family encoded by HSPA1, HSPA8, HSPA5 and HSPA9 genes, respectively. Methods: Literature reviews were conducted using HSPA1, HSPA5, HSPA8 and HSPA9 gene or protein names or synonyms combined with biological or cancer-relevant terms. Ingenuity Pathway Analysis was used to identify and compare profiles of proteins that directly bind individual chaperones and their associated pathways. TCGA data was probed to identify associations of hsc70 with cancer patient survival. ClinicalTrials.gov was used to identify HSP70 family studies. Results: The chaperones have similar protein folding functions. Their different cellular effects are determined by co-chaperones and client proteins combined with their intra- and extra-cellular localizations. Their upregulation is associated with worse patient prognosis in multiple cancers and can stimulate tumor immune responses or drug resistance. Their inhibition selectively kills cancer over healthy cells. Conclusions: Differences in Hsp70, hsc70, Grp78 and mortalin provide opportunities to calibrate HSP70 inhibitors for individual cancers and combination therapies.

Hsp70-containing extracellular vesicles are capable of activating of adaptive immunity in models of mouse melanoma and colon carcinoma

The release of Hsp70 chaperone from tumor cells is found to trigger the full-scale anti-cancer immune response. Such release and the proper immune reaction can be induced by the delivery of recombinant Hsp70 to a tumor and we sought to explore how the endogenous Hsp70 can be transported to extracellular space leading to the burst of anti-cancer activity. Hsp70 transport mechanisms were studied by analyzing its intracellular tracks with Rab proteins as well as by using specific inhibitors of membrane domains. To study Hsp70 forms released from cells we employed the assay consisting of two affinity chromatography methods. Hsp70 content in culture medium and extracellular vesicles (EVs) was measured with the aid of ELISA. The properties and composition of EVs were assessed using nanoparticle tracking analysis and immunoblotting. The activity of immune cells was studied using an assay of cytotoxic lymphocytes, and for in vivo studies we employed methods of affinity separation of lymphocyte fractions. Analyzing B16 melanoma cells treated with recombinant Hsp70 we found that the chaperone triggered extracellular transport of its endogenous analog in soluble and enclosed in EVs forms; both species efficiently penetrated adjacent cells and this secondary transport was corroborated with the strong increase of Natural Killer (NK) cell toxicity towards melanoma. When B16 and CT-26 colon cancer cells before their injection in animals were treated with Hsp70-enriched EVs, a powerful anti-cancer effect was observed as shown by a two-fold reduction in tumor growth rate and elevation of life span. We found that the immunomodulatory effect was due to the enhancement of the CD8-positive response and anti-tumor cytokine accumulation; supporting this there was no delay in CT-26 tumor growth when Hsp70-enriched EVs were grafted in nude mice. Importantly, pre-treatment of B16 cells with Hsp70-bearing EVs resulted in a decline of arginase-1-positive macrophages, showing no generation of tumor-associated macrophages. In conclusion, Hsp70-containing EVs generated by specifically treated cancer cells give a full-scale and effective pattern of anti-tumor immune responses.

Analysis of allergen components and identification of bioactivity of HSP70 in pollen of Populus deltoides

Background

Allergies caused by pollen from Populus deltoides are common, but the allergic components are still unclear.

Methods

The total proteins in pollen of P. deltoides were analyzed by proteomics, and the potential allergens were identified via the WHO/IUIS database and the allergenOnline database retrieval. One target protein was screened by bioinformatics and expressed in Escherichia coli. The biological activity of the expressed product was verified by animal experiments.

Results

The total of 3929 proteins in pollen of P. deltoides were identified, and 46 potential allergens belonging to 10 protein families were recognized by database retrieval. B9N9W6 protein of Hsp70 family was screened by bioinformatics analysis and expressed successfully. ELISA showed that B9N9W6 can stimulate the immune system to produce specific IgE and promote the generation of IL-4. Flow cytometry showed that B9N9W6 can significantly stimulate the proliferation of CD4⁺ T cells and promote the polarization of Th2 cells. The pathological sections of mice lung tissues indicated that alveolar destruction was more severe in the B9N9W6 group than that of extract group, and there were more inflammatory cells infiltration, mucus exudation and bleeding.

Conclusion

B9N9W6 is an important antigenic substance in the pollen of P. deltoides. Due to the conserved structure of Hsp70 family, more attention should be paid to the possibility of sensitization when Hsp70 from any pathogenic species is administered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12953-021-00178-8.

The interaction of heat shock proteins with cellular membranes: a historical perspective

The interaction of heat shock proteins (HSP) with cellular membranes has been an enigmatic process, initially observed by morphological studies, inferred during the purification of HSP70s, and confirmed after the detection of these proteins on the surface of cancer cells and their insertion into artificial lipid bilayers. Today, the association of several HSP with lipid membranes is well established. However, the mechanisms for membrane insertion have been elusive. There is conclusive evidence indicating that HSP70s have a great selectivity for negatively charged phospholipids, whereas other HSP have a broader spectrum of lipid specificity. HSP70 also oligomerizes upon membrane insertion, forming ion conductance channels. The functional role of HSP70 lipid interactions appears related to membrane stabilization that may play a role during cell membrane biogenesis. They could also play a role as membrane chaperones as well as during endocytosis, microautophagy, and signal transduction. Moreover, HSP membrane association is a key component in the extracellular export of these proteins. The presence of HSP70 on the surface of cancer cells and its interaction with lysosome membranes have been envisioned as potential therapeutic targets. Thus, the biology and function of HSP membrane association are reaching a new level of excitement. This review is an attempt to preserve the recollection of the pioneering contributions of many investigators that have participated in this endeavor.

Cancer Cytomembrane-Cloaked Prussian Blue Nanoparticles Enhance the Efficacy of Mild-Temperature Photothermal Therapy by Disrupting Mitochondrial Functions of Cancer Cells

Despite its success against cancer, photothermal therapy (PTT) (>50 °C) suffers from several limitations such as triggering inflammation and facilitating immune escape and metastasis and also damage to the surrounding normal cells. Mild-temperature PTT has been proposed to override these shortcomings. We developed a nanosystem using HepG2 cancer cell membrane-cloaked zinc glutamate-modified Prussian blue nanoparticles with triphenylphosphine-conjugated lonidamine (HmPGTL NPs). This innovative approach achieved an efficient mild-temperature PTT effect by downregulating the production of intracellular ATP. This disrupts a section of heat shock proteins that cushion cancer cells against heat. The physicochemical properties, anti-tumor efficacy, and mechanisms of HmPGTL NPs both in vitro and in vivo were investigated. Moreover, the nanoparticles cloaked with the HepG2 cell membrane substantially prolonged the circulation time in vivo. Overall, the designed nanocomposites enhance the efficacy of mild-temperature PTT by disrupting the production of ATP in cancer cells. Thus, we anticipate that the mild-temperature PTT nanosystem will certainly present its enormous potential in various biomedical applications.

Heat shock proteins and exosomes in cancer theranostics

Heat shock proteins (HSPs) are a superfamily of molecular chaperones that were discovered through their ability to be induced by different stresses including heat shock. Other than their function as chaperones in proteins homeostasis, HSPs have been shown to inhibit different forms of cell death and to participate in cell proliferation and differentiation processes. Because cancer cells have to rewire their metabolism, they require a high amount of these stress-inducible chaperones for their survival. Therefore, HSPs are unusually abundant in cancer cells where they have oncogene-like functions. In cancer, HSPs have been involved in the regulation of apoptosis, immune responses, angiogenesis, metastasis and treatment resistance. Recently, HSPs have been shown to be secreted through exosomes by cancer cells. These tumor-derived exosomes can be used as circulating markers: HSP-exosomes have been reported as biomarkers of cancer dissemination, response to therapy and/or patient outcome. A new range of functions, mostly in modulation of anticancer immune responses, have been described for these extracellular HSPs. In this review, we will describe those recently reported functions of HSP-exosomes that makes them both targets for anticancer therapeutics and biomarkers for the monitoring of the disease. We will also discuss their emerging interest in cancer vaccines.

The expression profiles and prognostic values of HSP70s in hepatocellular carcinoma

Background

The HSP70 family of heat shock protein plays a critical role in protein synthesis and transport to maintain protein homeostasis. Several studies have indicated that HSP70s are related to the development and occurrence of various cancers.

Methods

The relationship between the overall survival rate of hepatocellular carcinoma patients and the expression of 14 HSP70s from multiple databases, such as TCGA, ONCOMINE, cBioPortal was investigated. Western Blot and PCR were used to evaluate HSPA4 and HSPA14 expressions in various HCC cells to identify suitable cell lines for further experiments .Wound-healing assays, Transwell assays and EdU assays were used to verify the effects of HSPA4 and HSPA14 on the function of hepatocellular carcinoma cells, and statistical analysis was performed.

Results

Hepatocellular carcinoma tissues significantly expressed the 14 HSP70s compared to the normal samples. Besides, the high HSPA1A, HSPA1B, HSPA4, HSPA5, HSPA8, HSPA13, and HSPA14 expressions were inversely associated with the overall survival rate of patients, tumor grade, and cancer stage. A PPI regulatory network was constructed using the 14 HSP70s proteins with HSPA5 and HSPA8 at the network center. Univariate and multivariate analyses showed that HSPA4 and HSPA14 could be independent risk factors for the prognosis of hepatocellular carcinoma patients. Cell experiments have also confirmed that reducing HSPA4 and HSPA14 expressions can inhibit the invasion, metastasis, and proliferation of hepatocellular carcinoma cells.

Conclusions

Therefore, the HSP70s significantly influence the occurrence and development of hepatocellular carcinoma. For instance, HSPA4 and HSPA14 can be novel therapeutic targets and prognostic biomarkers for hepatocellular carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01987-9.

Ouabain-induced activation of phospholipase C zeta and its contributions to bovine sperm capacitation

The sperm-derived oocyte activating factor, phospholipase C zeta (PLC ζ), is the only PLC isoform reported in cattle. The objectives were to (1) localize PLC ζ in fresh and capacitated bovine sperm and (2) investigate the activation of PLC ζ during bull sperm capacitation and contributions of PLC activity to this process. We confirmed interaction of testis-specific isoform of Na/K-ATPase (ATP1A4) with PLC ζ (immunolocalization and immunoprecipitation) and tyrosine phosphorylation (immunoprecipitation) of PLC ζ (a post-translational protein modification commonly involved in activation of PLC in somatic cells) during capacitation. Furthermore, incubation of sperm under capacitating conditions upregulated PLC-mediated hyperactivated motility, tyrosine phosphoprotein content, acrosome reaction, and F-actin formation (flow cytometry), implying that PLC activity is enhanced during capacitation and contributing to these capacitation processes. In conclusion, we inferred that PLC ζ is activated during capacitation by tyrosine phosphorylation through a mechanism involving ATP1A4, contributing to capacitation-associated biochemical events.

The diagnostic value of urine heat shock protein 70 and prostatic exosomal protein in chronic prostatitis

Objective

To explore the diagnostic value of the levels of prostatic exosomal protein (PSEP) and heat shock protein 70 (HSP70) in the urine of patients with chronic prostatitis (CP).

Method

Urine samples from 210 CP patients (70 cases of the USA National Institutes of Health Category II [NIH‐II], 70 NIH‐IIIa, and 70 NIH‐IIIb patients) and 70 control subjects were collected between May 2018 and February 2020. The levels of PSEP and HSP70 in urine were detected by enzyme‐linked immunosorbent assay. The differences in urine PSEP and HSP70 levels between the groups were analyzed, and receiver operating characteristic (ROC) curves were used to analyze the clinical value of PSEP and HSP70 in the diagnosis of CP.

Results

The PSEP levels of CP patients were significantly higher than those of the control group (p < 0.001), but there was no difference in PSEP levels among CP subgroups. The level of HSP70 in the urine of the NIH‐II patients was significantly lower than the levels in the NIH‐IIIa and NIH‐IIIb subgroups and the control group, but there was no difference in HSP70 levels between the NIH‐IIIa and NIH‐IIIb subgroups and the control group. ROC curve analysis results showed that the area under the curve (AUC) of PSEP for the NIH‐II, NIH‐IIIa, and NIH‐IIIb patients was 0.751, 0.776, and 0.731, respectively. The AUC of HSP70 in NIH‐II patients was 0.784, and the AUC of combined detection of PSEP and HSP70 in NIH‐II patients was 0.858.

Conclusion

Urine PSEP can be used as a marker for the diagnosis of CP, but it cannot distinguish between the various types of CP, and HSP70 can be used as a diagnostic index for NIH‐II classification.

Mannose-Derived Carbon Dots Amplify Microwave Ablation-Induced Antitumor Immune Responses by Capturing and Transferring "Danger Signals" to Dendritic Cells

Hepatocellular carcinoma recurrence and metastasis after microwave ablation (MWA) are challenges in the clinic. This study showed that mannose-derived carbon dots (Man-CDs) could effectively capture several "danger signals" (DS) after MWA treatment and then deliver DS specifically to dendritic cells (DCs). This improved delivery of DS to DCs enhanced the processing and presentation of tumor-associated antigens by DCs. The results demonstrated that intratumoral injection of Man-CDs after MWA therapy elicited a potent tumor-specific immune response and finally led to the effective suppression of both primary and distant tumors. MWA + Man-CD treatment could efficiently reject tumor cell rechallenge in vivo. This study demonstrated that Man-CD nanoparticles are effective adjuvants that can improve MWA therapy by eliciting a tumor-specific immune response.

ATP5A1 Participates in Transcriptional and Posttranscriptional Regulation of Cancer-Associated Genes by Modulating Their Expression and Alternative Splicing Profiles in HeLa Cells

Background: Aberrant expression and alternative splicing of oncogenes are the driving events in tumor initiation and development. But how these events are regulated in cancer cells is largely unknown. Functions of ATP5A1, an important mitochondrial ATP synthase gene, in transcriptional and posttranscriptional regulation were explored in this study. Methods: ATP5A1 was overexpressed using plasmid-transformed HeLa cells, and its influence on cell apoptosis and proliferation is evaluated. Transcriptome sequencing was then performed using RNA-seq to study the changes in gene expression and regulation of alternative splicing events. Validation of the implicated genes was achieved using RT-qPCR analysis. Results: It was found that ATP5A1 could significantly promote cellular apoptosis, but it had no influence on cell proliferation. ATP5A1 overexpression significantly increased the expression levels of genes associated with the innate immune response, angiogenesis, and collagen catabolic processes. This included enrichment of MMP2 and MMP19. It was also found that ATP5A1 could interfere with the alternative splicing of hundreds of genes associated with glucose homeostasis, HIF-1 signaling activation, and several pathways associated with cancers. Eight ATP5A1-regulated differentially expressed genes and 3 genes altered by splicing were selected and validated using RT-qPCR analysis. Conclusions: In summary, we illustrate the regulatory functions of ATP5A1 on the transcriptome of HeLa cells by exploring its influence on gene expression and alternative splicing. The results suggest that ATP5A1 may play an important regulatory role in cervical cancer cells by regulating expression and alternative splicing of cancer-associated genes. This study provides novel insights into the current understanding of the mechanisms of ATP5A1 on carcinogenesis and cancer progression.

Critical insights into the interactions of heat shock protein 70 with phospholipids

Heat shock proteins (Hsps) stabilize the newly synthesized polypeptide chains preventing them from aggregation. They contribute to systemic response under stress and thus behave as signaling molecules. Hsp70 has been detected on the surface of stressed cells. It translocates to the extracellular environment through the plasma membrane without causing cell death. But the interaction of the protein with the membrane leading to the export process remains elusive. Hsp70 has a tendency to generate channels within lipid bilayers, and this has been a driving force for studying protein-lipid interactions. Transport of these proteins across the membrane paves their pathways for performing the desired function. We have attempted to characterize how the interaction of Hsp70 with negatively charged phospholipids affects the structure of lipids. This study will help in explaining the transport mechanism of proteins that are devoid of defined signaling pathways. The interaction of amino acids of Hsp70 with the head and tail group leads to the rearrangement of the hydration layer in contact with the bilayers. Critical analysis of the results obtained from small-angle X-ray scattering along with QCM-D provides valuable insights to analyze the effect of Hsp70 adsorption on an anionic POPS lipid bilayer.

Radiofrequency ablation in combination with an mTOR inhibitor restrains pancreatic cancer growth induced by intrinsic HSP70

Background

Radiofrequency ablation (RFA) is widely used in palliative therapy of malignant cancers. Several studies have shown its applicability and safety for locally advanced pancreatic cancer (LAPC). The objective of this study was to modify the current regimen to improve its therapeutic effect.

Methods

Immune cell subtypes and related cytokines were quantified to uncover the immune pattern changes post-RFA treatment. Then, high-throughput proteome analysis was performed to identify differentially expressed proteins associated with RFA, which were further validated in in vitro and in vivo experiments. Finally, a combined therapy was tested in a murine model to observe its therapeutic effect.

Results

In preclinical murine models of RFA treatment, no significant therapeutic benefit was observed following RFA treatment. However, the proportion of tumor-infiltrating CD8⁺ T cells was significantly increased, whereas that of regulatory T cells (Tregs) was decreased post-RFA treatment, which indicated a beneficial anti-tumor environment. To identify the mechanism, high-throughput mass spectrum was obtained that identified heat shock protein 70 (HSP70) as the top differentially expressed protein. HSP70 expression in residual cancer cells was significantly increased post-RFA treatment, which notably promoted pancreatic cancer growth. Elevated HSP70 promoted cell proliferation by activating AKT-mTOR signaling. Finally, RFA treatment combined with an mTOR inhibitor exerted a synergetic repressive effect on tumor growth in the preclinical murine cancer model.

Conclusions

RFA treatment in combination with mTOR signaling blockade can not only promote tumor immune response, but also restrain residual cancer cell proliferation. Such a combination may be a promising and effective therapeutic strategy for LAPC patients.

Heat shock protein 70 positively regulates transforming growth factor-α-induced hepatocellular carcinoma cell migration via the AKT signaling pathway

Heat shock proteins (HSPs) are induced in response to extracellular stress and manage the quality of proteins as molecular chaperones. HSP70, a highly conserved HSP, has been reported to correlate with the proliferation and migration of human cancer cells, such as oral, prostate, lung and liver cancer. Regarding hepatocellular carcinoma (HCC), the HSP70 levels in the tumor tissues from patients are significantly higher than those in the normal liver tissues. HSP70 reportedly upregulates the migration and invasion of HCC. The AKT, p38 mitogen-activated protein kinase (MAPK), c-jun N-terminal kinase (JNK) and Rho-kinase signaling pathways regulate the transforming growth factor (TGF)-α-induced migration of human HCC-derived HuH7 cells. However, the exact mechanism underlying the role of HSP70 in growth factor-induced HCC migration remains unclear. Therefore, in the present study, the mechanism underlying the involvement of HSP70 in TGF-α-induced HCC cell migration was investigated. Treatment with the HSP70 inhibitors VER155008 and YM-08 and the downregulation of HSP70 protein were confirmed to significantly suppress the TGF-α-induced cell migration of HuH7 cells. Both VER155008 and YM-08 reduced the TGF-α-induced phosphorylation of AKT without affecting the phosphorylation of p38 MAPK, JNK or Rho-kinase. These results strongly suggest that HSP70 positively regulates the TGF-α-induced migration of HCC cells via the AKT signaling pathway.

Targets for protection and mitigation of radiation injury

Protection of normal tissues against toxic effects of ionizing radiation is a critical issue in clinical and environmental radiobiology. Investigations in recent decades have suggested potential targets that are involved in the protection against radiation-induced damages to normal tissues and can be proposed for mitigation of radiation injury. Emerging evidences have been shown to be in contrast to an old dogma in radiation biology; a major amount of reactive oxygen species (ROS) production and cell toxicity occur during some hours to years after exposure to ionizing radiation. This can be attributed to upregulation of inflammatory and fibrosis mediators, epigenetic changes and disruption of the normal metabolism of oxygen. In the current review, we explain the cellular and molecular changes following exposure of normal tissues to ionizing radiation. Furthermore, we review potential targets that can be proposed for protection and mitigation of radiation toxicity.

Molecular effects of dADD1 misexpression in chromatin organization and transcription

Background

dADD1 and dXNP proteins are the orthologs in Drosophila melanogaster of the ADD and SNF2 domains, respectively, of the ATRX vertebrate’s chromatin remodeler, they suppress position effect variegation phenotypes and participate in heterochromatin maintenance.

Results

We performed a search in human cancer databases and found that ATRX protein levels were elevated in more than 4.4% of the samples analyzed. Using the Drosophila model, we addressed the effects of over and under-expression of dADD1 proteins in polytene cells. Elevated levels of dADD1 in fly tissues caused different phenotypes, such as chromocenter disruption and loss of banding pattern at the chromosome arms. Analyses of the heterochromatin maintenance protein HP1a, the dXNP ATPase and the histone post-translational modification H3K9me3 revealed changes in their chromatin localization accompanied by mild transcriptional defects of genes embedded in heterochromatic regions. Furthermore, the expression of heterochromatin embedded genes in null dadd1 organisms is lower than in the wild-type conditions.

Conclusion

These data indicate that dADD1 overexpression induces chromatin changes, probably affecting the stoichiometry of HP1a containing complexes that lead to transcriptional and architectural changes. Our results place dADD1 proteins as important players in the maintenance of chromatin architecture and heterochromatic gene expression.