Heat shock proteins, thermotolerance, and their relevance to clinical hyperthermia

Insights on early response to acute heat shock of bovine mammary epithelial cells through a multimethod approach

Heat stress is a significant challenge in dairy cattle herds, affecting milk production and quality, and generating important changes at the cellular level. Most in vitro research on heat shock (HS) effects on dairy cow mammary cells was focused on medium-long-term effects. In recent years, Fourier transform-infrared (FT-IR) micro-spectroscopy has been increasingly used to study the effects of several external stresses on different cell lines, down to the level of single cellular components, such as DNA/RNA, lipids, and proteins. In this study, the possible changes at the biochemical and molecular level induced by acute (30 min-2 h) HS in bovine mammary epithelial (BME-UV1) cells were investigated. The cells were exposed to different temperatures, thermoneutral (TN, 37 °C) and HS (42 °C), and FT-IR spectra were acquired to analyse the effects of HS on biochemical characteristics of BME-UV1 cellular components (proteins, lipids, and DNA/RNA). Moreover, cell viability assay, reactive oxygen species production, and mRNA expression of heat shock proteins (HSPA1A, HSP90AA1, GRP78, GRP94) and antioxidant genes (SOD1, SOD2) by RT-qPCR were also analysed. The FT-IR results showed a change already at 30 min of HS exposure, in the content of long-chain fatty acids, which probably acted as a response to a modification of membrane fluidity in HS cells compared with TN cells. After 2 h of HS exposure, modification of DNA/RNA activity and accumulation of aggregated proteins was highlighted in HS cells. The gene expression analyses showed the overexpression of HSPA1A and HSP90AA1 starting from 30 min up to 2 h in HS cells compared with TN cells. At 2 h of HS exposure, also the overexpression of GRP94 was observed in HS cells. Acute HS did not affect cell viability, reactive oxygen species level, and SOD1 and SOD2 gene expression of BME-UV1 cells. According to the results obtained, cells initiate early defence mechanisms in case of acute HS and probably this efficient response capacity may be decisive for tolerance to heat stress of dairy cattle.

Treatment of Pelvic and Spinal Bone Metastases: Radiotherapy and Hyperthermia Alone vs. in Combination

Painful pelvic and spinal bone metastases are a considerable challenge for doctors and patients. Conventional therapies include morphine-equivalent medication (MeM) and local radiotherapy (RT), but these interventions are not always successful. More recently, hyperthermia (HT) has been applied to complement RT and MeM, and this complex approach has shown promising synergistic results. The objective of our study was to present the results of RT combined with a special kind of HT (modulated electrohyperthermia, mEHT), in which some of the thermal effect is contributed by equivalent nonthermal components, drastically reducing the necessary power and energy. This retrospective study included 61 patients divided into three groups with pelvic and spinal bone metastases to compare the effects of RT and mEHT alone and in combination (RT + mEHT). A detailed evaluation of pain intensity, measured by the brief pain inventory score, MeM use, and breakthrough pain episodes, revealed no significant differences between RT and mEHT alone; thus, these individual methods were considered equivalent. However, RT + mEHT yielded significantly better results in terms of the above parameters. Clinically, mEHT has a lower risk of adverse thermal effects, and due to its efficacy, mEHT can be used to treat RT-resistant lesions.

Theoretical evaluation of the impact of diverse treatment conditions by calculation of the tumor control probability (TCP) of simulated cervical cancer Hyperthermia-Radiotherapy (HT-RT) treatments in-silico

INTRODUCTION

Hyperthermia (HT) induces various cellular biological processes, such as repair impairment and direct HT cell killing. In this context, in-silico biophysical models that translate deviations in the treatment conditions into clinical outcome variations may be used to study the extent of such processes and their influence on combined hyperthermia plus radiotherapy (HT + RT) treatments under varying conditions.

METHODS

An extended linear-quadratic model calibrated for SiHa and HeLa cell lines (cervical cancer) was used to theoretically study the impact of varying HT treatment conditions on radiosensitization and direct HT cell killing effect. Simulated patients were generated to compute the Tumor Control Probability (TCP) under different HT conditions (number of HT sessions, temperature and time interval), which were randomly selected within margins based on reported patient data.

RESULTS

Under the studied conditions, model-based simulations suggested a treatment improvement with a total CEM43 thermal dose of approximately 10 min. Additionally, for a given thermal dose, TCP increased with the number of HT sessions. Furthermore, in the simulations, we showed that the TCP dependence on the temperature/time interval is more correlated with the mean value than with the minimum/maximum value and that comparing the treatment outcome with the mean temperature can be an excellent strategy for studying the time interval effect.

CONCLUSION

The use of thermoradiobiological models allows us to theoretically study the impact of varying thermal conditions on HT + RT treatment outcomes. This approach can be used to optimize HT treatments, design clinical trials, and interpret patient data.

Anti-CD38 targeted nanotrojan horses stimulated by acoustic waves as therapeutic nanotools selectively against Burkitt's lymphoma cells

The horizon of nanomedicine research is moving toward the design of therapeutic tools able to be completely safe per se, and simultaneously be capable of becoming toxic when externally activated by stimuli of different nature. Among all the stimuli, ultrasounds come to the fore as an innovative approach to produce cytotoxicity on demand in presence of NPs, without invasiveness, with high biosafety and low cost. In this context, zinc oxide nanoparticles (NPs) are among the most promising metal oxide materials for theranostic application due to their optical and semi-conductor properties, high surface reactivity, and their response to ultrasound irradiation. Here, ZnO nanocrystals constitute the stimuli-responsive core with a customized biomimicking lipidic shielding, resembling the composition of natural extracellular vesicles. This core-shell hybrid structure provides high bio- and hemocompatibility towards healthy cells and is here proofed for the treatment of Burkitt's Lymphoma. This is a very common haematological tumor, typically found in children, for which consolidated therapies are so far the combination of chemo-therapy drugs and targeted immunotherapy. In this work, the proposed safe-by-design antiCD38-targeted hybrid nanosystem exhibits an efficient selectivity toward cancerous cells, and an on-demand activation, leading to a significant killing efficacy due to the synergistic interaction between US and targeted hybrid NPs. Interestingly, this innovative treatment does not significantly affect healthy B lymphocytes nor a negative control cancer cell line, a CD38- acute myeloid leukemia, being thus highly specific and targeted. Different characterization and analyses confirmed indeed the effective formation of targeted hybrid ZnO NPs, their cellular internalization and the damages produced in Burkitt's Lymphoma cells only with respect to the other cell lines. The presented work holds promises for future clinical applications, as well as translation to other tumor types.

Hydrogel design to overcome thermal resistance and ROS detoxification in photothermal and photodynamic therapy of cancer

Responsive heat resistance (by heat shock protein upregulation) and spontaneous reactive oxygen species (ROS) detoxification have been regarded as the major obstacles for photothermal/photodynamic therapy of cancer. To overcome the thermal resistance and improve ROS susceptibility in breast cancer therapy, Au ion-crosslinked hydrogels including indocyanine green (ICG) and polyphenol are devised. Au ion has been introduced for gel crosslinking (by catechol-Au3+ coordination), cellular glutathione depletion, and O2 production from cellular H2O2. ICG can generate singlet oxygen from O2 (for photodynamic therapy) and induce hyperthermia (for photothermal therapy) under the near-infrared laser exposure. (-)-Epigallocatechin gallate downregulates heat shock protein to overcome heat resistance during hyperthermia and exerts multiple anticancer functions in spite of its ironical antioxidant features. Those molecules are concinnously engaged in the hydrogel structure to offer fast gel transformation, syringe injection, self-restoration, and rheological tuning for augmented photo/chemotherapy of cancer. Intratumoral injection of multifunctional hydrogel efficiently suppressed the growth of primary breast cancer and completely eliminated the residual tumor mass. Proposed hydrogel system can be applied to tumor size reduction prior to surgery of breast cancer and the complete remission after its surgery.

Ultrasmall Bi/Cu Coordination Polymer Combined with Glucose Oxidase for Tumor Enhanced Chemodynamic Therapy by Starvation and Photothermal Treatment

Multi-modal combination therapy for tumor is expected to have superior therapeutic effect compared with monotherapy. In this study, a super-small bismuth/copper-gallic acid coordination polymer nanoparticle (BCN) protected by polyvinylpyrrolidone is designed, which is co-encapsulated with glucose oxidase (GOX) by phospholipid to obtain nanoprobe BCGN@L. It shows that BCN has an average size of 1.8 ± 0.7 nm, and photothermal conversion of BCGN@L is 31.35% for photothermal imaging and photothermal therapy (PTT). During the treatment process of 4T1 tumor-bearing nude mice, GOX catalyzes glucose in the tumor to generate gluconic acid and hydrogen peroxide (H2 O2 ), which reacts with copper ions (Cu2+ ) to produce toxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT) and new fresh oxygen (O2 ) to supply to GOX for further catalysis, preventing tumor hypoxia. These reactions increase glucose depletion for starvation therapy , decrease heat shock protein expression, and enhance tumor sensitivity to low-temperature PTT. The in vitro and in vivo results demonstrate that the combination of CDT with other treatments produces excellent tumor growth inhibition. Blood biochemistry and histology analysis suggests that the nanoprobe has negligible toxicity. All the positive results reveal that the nanoprobe can be a promising approach for incorporation into multi-modal anticancer therapy.

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.

Heat stress adaptation in cows - Physiological responses and underlying molecular mechanisms

Heat stress is a key abiotic stressor for dairy production in the tropics which is further compounded by the ongoing climate change. Heat stress not only adversely impacts the production and welfare of dairy cows but severely impacts the economics of dairying due to production losses and increased cost of rearing. Over the years, selection has ensured development of high producing breeds, however, the thermotolerance ability of animals has been largely overlooked. In the past decade, the ill effects of climate change have made it pertinent to rethink the selection strategies to opt for climate resilient breeds, to ensure optimum production and reproduction. This has led to renewed interest in evaluation of the impacts of heat stress on cows and the underlying mechanisms that results in their acclimatization and adaptation to varied thermal ambience. The understanding of heat stress and associated responses at various level of animal is crucial to device amelioration strategies to secure optimum production and welfare of cows. With this review, an effort has been made to provide an overview on temperature humidity index as an important indicator of heat stress, general effect of heat stress in dairy cows, and impact of heat stress and subsequent response at physiological, haematological, molecular and genetic level of dairy cows.

Carbohydrate, but not fat, oxidation is reduced during moderate-intensity exercise performed in 33 vs. 18 °C at matched heart rates

PURPOSE

Exposure to environmental heat stress increases carbohydrate oxidation and extracellular heat shock protein 70 (HSP70) concentrations during endurance exercise at matched absolute, external work rates. However, a reduction in absolute work rate typically occurs when unacclimated endurance athletes train and/or compete in hot environments. We sought to determine the effect of environmental heat stress on carbohydrate oxidation rates and plasma HSP70 expression during exercise at matched heart rates (HR).

METHODS

Ten endurance-trained, male cyclists performed two experimental trials in an acute, randomised, counterbalanced cross-over design. Each trial involved a 90-min bout of cycling exercise at 95% of the HR associated with the first ventilatory threshold in either 18 (TEMP) or 33 °C (HEAT), with ~ 60% relative humidity.

RESULTS

Mean power output (17 ± 11%, P < 0.001) and whole-body energy expenditure (14 ± 8%, P < 0.001) were significantly lower in HEAT. Whole-body carbohydrate oxidation rates were significantly lower in HEAT (19 ± 11%, P = 0.002), while fat oxidation rates were not different between-trials. The heat stress-induced reduction in carbohydrate oxidation was associated with the observed reduction in power output (r = 0.64, 95% CI, 0.01, 0.91, P = 0.05) and augmented sweat rates (r = 0.85, 95% CI, 0.49, 0.96, P = 0.002). Plasma HSP70 and adrenaline concentrations were not increased with exercise in either environment.

CONCLUSION

These data contribute to our understanding of how moderate environmental heat stress is likely to influence substrate oxidation and plasma HSP70 expression in an ecologically-valid model of endurance exercise.

pH-responsive upconversion mesoporous silica nanospheres for combined multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) have garnered considerable interest as non-invasive cancer treatment modalities. However, these approaches remain limited by low solubility, poor stability and inefficient targeting of many common photosensitizers (PSs) and photothermal agents (PTAs). To overcome these limitations, we have designed biocompatible and biodegradable tumor-targeted upconversion nanospheres with imaging capabilities. The multifunctional nanospheres consist of a sodium yttrium fluoride core doped with lanthanides (ytterbium, erbium and gadolinium) and bismuth selenide (NaYF 4 :Yb/Er/Gd,Bi 2 Se 3 ) within a mesoporous silica shell that encapsulates a PS, Chlorin e6 (Ce6), in its pores. NaYF 4 :Yb/Er converts deeply penetrating near-infrared (NIR) light to visible light, which excites the Ce6 to generate cytotoxic reactive oxygen species (ROS), while the PTA Bi 2 Se 3 efficiently converts absorbed NIR light to heat. Additionally, Gd enables magnetic resonance imaging (MRI) of the nanospheres. The mesoporous silica shell is coated with lipid/polyethylene glycol (DPPC/cholesterol/DSPE-PEG) to ensure retention of the encapsulated Ce6 and minimize interactions with serum proteins and macrophages that impede tumor targeting. Finally, the coat is functionalized with the acidity-triggered rational membrane (ATRAM) peptide, which promotes specific and efficient internalization into cancer cells within the mildly acidic tumor microenvironment. Following uptake by cancer cells in vitro , NIR laser irradiation of the nanospheres caused substantial cytotoxicity due to ROS production and hyperthermia. The nanospheres facilitated tumor MRI and thermal imaging, and exhibited potent NIR laser light-induced antitumor effects in vivo via combined PDT and PTT, with no observable toxicity to healthy tissue, thereby substantially prolonging survival. Our results demonstrate that the ATRAM-functionalized, lipid/PEG-coated upconversion mesoporous silica nanospheres (ALUMSNs) offer multimodal diagnostic imaging and targeted combinatorial cancer therapy.

Is CIS a Contraindication to Hyperthermic Intravesical Chemotherapy (HIVEC) after BCG-Failure?

CIS of the bladder is associated with a high risk of progression. In the case of BCG failure, radical cystectomy should be performed. For patients who refuse or are ineligible, bladder-sparing alternatives are evaluated. This study aims to investigate the efficacy of Hyperthermic IntraVesical Chemotherapy (HIVEC) depending on the presence or absence of CIS. This retrospective, multicenter study was conducted between 2016 and 2021. Patients with non-muscle-invasive bladder cancer (NMIBC) with BCG failure received 6-8 adjuvant instillations of HIVEC. The co-primary endpoints were recurrence-free survival (RFS) and progression-free survival (PFS). A total of 116 consecutive patients met our inclusion criteria of whom 36 had concomitant CIS. The 2-year RFS rate was 19.9% and 43.7% in patients with and without CIS, respectively (p = 0.52). Fifteen patients (12.9%) experienced progression to muscle-invasive bladder cancer with no significant difference between patients with and without CIS (2-year PFS rate = 71.8% vs. 88.8%, p = 0.32). In multivariate analysis, CIS was not a significant prognostic factor in terms of recurrence or progression. In conclusion, CIS may not be considered a contraindication to HIVEC, as there is no significant association between CIS and the risk of progression or recurrence after treatment.

Enhanced mild-temperature photothermal therapy by pyroptosis-boosted ATP deprivation with biodegradable nanoformulation

BACKGROUND

Mild-temperature photothermal therapy (mild PTT) is a safe and promising tumor therapeutic modality by alleviating the damage of healthy tissues around the tumor due to high temperature. However, its therapeutic efficiency is easily restricted by heat shock proteins (HSPs). Thus, exploitation of innovative approaches of inhibiting HSPs to enhance mild PTT efficiency is crucial for the clinical application of PTT.

RESULTS

Herein, an innovative strategy is reported: pyroptosis-boosted mild PTT based on a Mn-gallate nanoformulation. The nanoformulation was constructed via the coordination of gallic acid (GA) and Mn²⁺. It shows an acid-activated degradation and releases the Mn²⁺ and GA for up-regulation of reactive oxygen species (ROS), mitochondrial dysfunction and pyroptosis, which can result in cellular ATP deprivation via both the inhibiton of ATP generation and incresed ATP efflux. The reduction of ATP and accumulation of ROS provide a powerful approach for inhibiting the expression of HSPs, which enables the nanoformulation-mediated mild PTT.

CONCLUSIONS

Our in-vitro and in-vivo results demonstrate that this strategy of pyroptosis-assited PTT can achieve efficient mild PTT efficiency for osteosarcoma therapy.

Mahuang Xixin Fuzi decoction ameliorates apoptosis via the mitochondrial-mediated signaling pathway in MCM cells

ETHNOPHARMACOLOGICAL RELEVANCE

Mahuang Xixin Fuzi Decoction (MXF), as a classical prescription of traditional Chinese medicine (TCM), has been used to treat the symptoms of fever, nasal congestion and headache in elderly people for almost a thousand years.

AIM OF THE STUDY

The purpose of this study was to evaluate the effects and possible mechanisms of MXF on thermal stimulation-induced mouse cardiac myocytes (MCM) cell apoptosis.

MATERIALS AND METHODS

The apoptosis of the MCM cell model was induced by a PCR-calculated temperature control system with a gradual heating pattern at 43 °C for 1 h. The cytotoxic effects were determined using real-time cell analyzer (RTCA) technology. Annexin V-FITC/7-AAD staining, and JC-1 fluorescence were used to assess apoptosis. Specific substrates, enzyme-linked immunosorbent assays (ELISAs), and Western blotting were used to identify proteins in the mitochondrial-mediated pathway. The identification of chemical components in the mouse heart was performed by ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry analysis.

RESULTS

MXF inhibited apoptosis through the mitochondrial-mediated signaling pathway, including ameliorating ∆Ψm reduction, blocking mitochondrial Cyt C release, reducing Bax levels and increasing Bcl-2 levels, suppressing caspase-9 and caspase-3 activation in cytoplasmic fractions. Moreover, the components of MXF that act on the heart are mainly ephedra alkaloids and aconitine alkaloids.

CONCLUSIONS

The findings demonstrated that MXF treatment markedly reduced MCM cell apoptosis induced by thermal stimulation, which may be ascribed to the mitochondrial-mediated signaling pathway.

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.

The Effect of Global Warming on Complex Disorders (Mental Disorders, Primary Hypertension, and Type 2 Diabetes)

Multiple studies imply a strong relationship between global warming (GW) and complex disorders. This review summarizes such reports concentrating on three disorders-mental disorders (MD), primary hypertension, and type 2 diabetes (T2D). We also attempt to point at potential mechanisms mediating the effect of GW on these disorders. Concerning mental disorders, immediate candidates are brain levels of heat-shock proteins (HSPs). In addition, given that heat stress increases reactive oxygen species (ROS) levels which may lead to blood-brain barrier (BBB) breakdown and, hence, enhanced protein extravasation in the brain, this might finally cause, or exacerbate mental health. As for hypertension, since its causes are incompletely understood, the mechanism(s) by which heat exposure affects blood pressure (BP) is an open question. Since the kidneys participate in regulating blood volume and BP they are considered as a site of heat-associated disease, hence, we discuss hyperosmolarity as a potential mediator. In addition, we relate to autoimmunity, inflammation, sodium excretion, and HSP70 as risk factors that might play a role in the effect of heat on hypertension. In the case of T2D, we raise two potential mediators of the effect of exposure to ambient hot environment on the disease's incidence-brown adipose tissue metabolism and HSPs.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Biomimetic nanoparticles for effective mild temperature photothermal therapy and multimodal imaging

Downregulation of adenosine triphosphate (ATP)-dependent heat shock proteins (HSPs) can significantly reduce the tumorigenicity of cancer cells and overcome heat endurance to achieve high-performance mild temperature (≤45 °C) photothermal therapy (PTT). Herein, we designed and constructed 4T1 cancer cell membrane-coated, lonidamine (LN)-loaded and DL-menthol (DLM)-loaded hollow mesoporous Prussian blue nanoparticles (PBLM@CCM NPs). DLM with mild phase change characteristics served as a plugging agent to avoid early leakage and allow thermally controllable release of LN, which enabled selective intracellular delivery of LN to reduce the HSPs and overcome the heat endurance in PTT by inhibiting the generation of intracellular ATP. The biocompatible PBLM@CCM NPs with good tumor targeting efficiency achieved high-efficiency mild temperature PTT. Meanwhile, PBLM@CCM NPs could allow photoacoustic (PA) imaging and generate heat to promote the phase change of DLM for ultrasound (US) imaging, which is of great value for future clinical translational studies.

Clinical Evidence for Thermometric Parameters to Guide Hyperthermia Treatment

Hyperthermia (HT) is a cancer treatment modality which targets malignant tissues by heating to 40-43 °C. In addition to its direct antitumor effects, HT potently sensitizes the tumor to radiotherapy (RT) and chemotherapy (CT), thereby enabling complete eradication of some tumor entities as shown in randomized clinical trials. Despite the proven efficacy of HT in combination with classic cancer treatments, there are limited international standards for the delivery of HT in the clinical setting. Consequently, there is a large variability in reported data on thermometric parameters, including the temperature obtained from multiple reference points, heating duration, thermal dose, time interval, and sequence between HT and other treatment modalities. Evidence from some clinical trials indicates that thermal dose, which correlates with heating time and temperature achieved, could be used as a predictive marker for treatment efficacy in future studies. Similarly, other thermometric parameters when chosen optimally are associated with increased antitumor efficacy. This review summarizes the existing clinical evidence for the prognostic and predictive role of the most important thermometric parameters to guide the combined treatment of RT and CT with HT. In conclusion, we call for the standardization of thermometric parameters and stress the importance for their validation in future prospective clinical studies.

Effects of Selenium as a Dietary Source on Performance, Inflammation, Cell Damage, and Reproduction of Livestock Induced by Heat Stress: A Review

Heat stress as a result of global warming has harmful consequences for livestock and is thus becoming an urgent issue for animal husbandry worldwide. Ruminants, growing pigs, and poultry are very susceptible to heat stress because of their fast growth, rapid metabolism, high production levels, and sensitivity to temperature. Heat stress compromises the efficiency of animal husbandry by affecting performance, gastrointestinal health, reproductive physiology, and causing cell damage. Selenium (Se) is an essential nutritional trace element for livestock production, which acts as a structural component in at least 25 selenoproteins (SELs); it is involved in thyroid hormone synthesis, and plays a key role in the antioxidant defense system. Dietary Se supplementation has been confirmed to support gastrointestinal health, production performance, and reproductive physiology under conditions of heat stress. The underlying mechanisms include the regulation of nutrient digestibility influenced by gastrointestinal microorganisms, antioxidant status, and immunocompetence. Moreover, heat stress damage to the gastrointestinal and mammary barrier is closely related to cell physiological functions, such as the fluidity and stability of cellular membranes, and the inhibition of receptors as well as transmembrane transport protein function. Se also plays an important role in inhibiting cell apoptosis and reducing cell inflammatory response induced by heat stress. This review highlights the progress of research regarding the dietary supplementation of Se in the mitigation of heat stress, addressing its mechanism and explaining the effect of Se on cell damage caused by heat stress, in order to provide a theoretical reference for the use of Se to mitigate heat stress in livestock.

Cascade-responsive nano-assembly for efficient photothermal-chemo synergistic inhibition of tumor metastasis by targeting cancer stem cells

Metastasis has been widely recognized as the most lethal threats for cancer patients. Due to their special genetic and environmental context, cancer stem cells (CSCs) which are resistant to most cytotoxic drugs and radiation, are considered as the dominant culprit for metastasis. Thus, the efficient targeting and thorough elimination of CSCs are significantly urgent for the enhancement of therapeutic efficacy. Herein, we developed a facile and smart photothermal-chemo therapeutic nano-assembly system, of which the surface was modified by a sheddable PEG shell and acid-activatable pro-penetration peptide, to surmount the physiological barriers in targeting CSCs. A highly-efficient diradical-featured croconium-based photothermal agent and a natural cytotoxic heat shock protein (HSP) inhibitor were co-loaded in redox-sensitive chitosan matrices to realize the synergistic photothermal-chemo therapy. Within solid tumors, the PEG shell that prevents the nano-assembly from mononuclear phagocytic clearance could rapidly leave to expose the positively charged chitosan, and the detached iRGD could further actuate the tumor penetration of chitosan nanoparticles, and allow the CSCs targeting by selective recognition of CD44 protein. Owing to the HSP inhibition and chemo-sensitization, both the CSCs and non-CSCs could be thoroughly eliminated by the designed nano-assembly, largely inhibiting the tumor growth and metastasis. This work provides a potential strategy for CSCs-targeting drug delivery to solve the CSCs-related metastasis.

Targeting Hypoxia: Revival of Old Remedies

Tumour hypoxia is significantly correlated with patient survival and treatment outcomes. At the molecular level, hypoxia is a major driving factor for tumour progression and aggressiveness. Despite the accumulative scientific and clinical efforts to target hypoxia, there is still a need to find specific treatments for tumour hypoxia. In this review, we discuss a variety of approaches to alter the low oxygen tumour microenvironment or hypoxia pathways including carbogen breathing, hyperthermia, hypoxia-activated prodrugs, tumour metabolism and hypoxia-inducible factor (HIF) inhibitors. The recent advances in technology and biological understanding reveal the importance of revisiting old therapeutic regimens and repurposing their uses clinically.

A NIR-triggered multifunctional nanoplatform mediated by Hsp70 siRNA for chemo-hypothermal photothermal synergistic therapy

Recently, hypothermal photothermal therapy (HPTT) seemed essential for the future clinical transformation of cancer optical therapies. However, at a lower working temperature, heat shock proteins (HSPs) seriously affect the anti-tumor effect of HPTT. This work reports a reasonable design of a dual-responsive nanoplatform for the synergistic treatment of chemotherapy and HPTT. We adopted a one-step method to wrap indocyanine green (ICG) into imidazole skeleton-8 (ZIF-8) and further loaded it with the chemotherapy drug doxorubicin (DOX). Furthermore, we introduced Hsp-70 siRNA to block the affection of HSPs at an upstream node, thereby avoiding the side effects of traditional heat shock protein inhibitors. The prepared ZIF-8@ICG@DOX@siRNA nanoparticles (ZID-Si NPs) could significantly improve the stability of siRNA to effectively down-regulate the expression of HSP70 protein during the photothermal therapy, thus realizing the pH-controlled and NIR-triggered release of the chemotherapeutical drug DOX. Moreover, tumors were also imaged accurately by ICG wrapped in ZID-Si nanoparticles. After the evaluation of the in vitro and in vivo photothermal effect as well as the anti-tumor activity, we found that the added Hsp-70 siRNA enhanced the synergistic anti-cancer activity of HPTT and chemotherapy. In summary, this work holds great potential in cancer treatment, and suggests better efficacy of synergistic chemo/HPTT than the single-agent therapy.

Mitochondria-Targeted Nanomedicine for Enhanced Efficacy of Cancer Therapy

Nanomedicines have been designed and developed to deliver anticancer drugs or exert anticancer therapy more selectively to tumor sites. Recent investigations have gone beyond delivering drugs to tumor tissues or cells, but to intracellular compartments for amplifying therapy efficacy. Mitochondria are attractive targets for cancer treatment due to their important functions for cells and close relationships to tumor occurrence and metastasis. Accordingly, multifunctional nanoplatforms have been constructed for cancer therapy with the modification of a variety of mitochondriotropic ligands, to trigger the mitochondria-mediated apoptosis of tumor cells. On this basis, various cancer therapeutic modalities based on mitochondria-targeted nanomedicines are developed by strategies of damaging mitochondria DNA (mtDNA), increasing reactive oxygen species (ROS), disturbing respiratory chain and redox balance. Herein, in this review, we highlight mitochondria-targeted cancer therapies enabled by nanoplatforms including chemotherapy, photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), radiodynamic therapy (RDT) and combined immunotherapy, and discussed the ongoing challenges.

Hyperthermic intraperitoneal chemotherapy enhances antitumor effects on ovarian cancer through immune-mediated cancer stem cell targeting

PURPOSE

We aimed to determine the effects and possible mechanisms of hyperthermic intraperitoneal chemotherapy (HIPEC) in targeting ovarian cancer stem-like cells (CSCs).

METHODS

Murine ovarian cancer cell lines presenting CSC surface markers were grown intraperitoneally in both immunocompetent and immunodeficient mice, which were then treated by intraperitoneal hyperthermia with the chemotherapeutic agents: paclitaxel and cisplatin. Tumor growth was measured by non-invasive luminescent imaging. Intraperitoneal immune cells, such as CD4⁺, CD8⁺ T cells, macrophages, and dendritic cells, were evaluated through flow cytometry analysis.

RESULTS

Combined hyperthermia and chemotherapy exhibited an efficient therapeutic effect in the immunocompetent mice. However, a similar effect was not observed in the immunodeficient mice. Intraperitoneal hyperthermia increased the number of Intraperitoneal macrophages and dendritic cells that were lost due to chemotherapy. Compared with ovarian cancer bulk cells, CSCs were more susceptible to phagocytosis by macrophages.

CONCLUSION

We demonstrated that the superior therapeutic efficacy and reduced proportion of CSCs associated with intraperitoneal hyperthermic chemotherapy were immune-related. Hyperthermia recruits the phagocytes that target surviving CSCs after chemotherapy. These results provide a novel mechanism for the efficacy of HIPEC in treating ovarian cancer.

Recent near-infrared light-activated nanomedicine toward precision cancer therapy

Light has been present throughout the history of mankind and even the universe. It is of great significance to human life, contributing to energy, agriculture, communication, and much more. In the biomedical field, light has been developed as a switch to control medical processes with minimal invasion and high spatiotemporal selectivity. During the past three years, near-infrared (NIR) light as long-wavelength light has been applied to more than 3000 achievements in biological applications due to its deep penetration depth and low phototoxicity. Remotely controlled cancer therapy usually involves the conversion of biologically inert NIR light. Thus, various materials, especially nanomaterials that can generate reactive oxygen species (ROS), ultraviolet (UV)/visual light, or thermal energy and so on under NIR illumination achieve great potential for the research of nanomedicine. Here, we offered an overview of recent advances in NIR light-activated nanomedicine for cancer therapeutic applications. NIR-light-conversion nanotechnologies for both directly triggering nanodrugs and smart drug delivery toward tumor therapy were discussed emphatically. The challenges and future trends of the use of NIR light in biomedical applications were also provided as a conclusion. We expect that this review will spark inspiration for biologists, materials scientists, pharmacologists, and chemists to fight against diseases and boost the future clinical-translational applications of NIR technology-based precision nanomedicine.

One step assembly of ginsenoside Rb1-based nanovehicles with fast cellular transport in photothermal-chemical combined cancer therapy

Nowadays, the research of photothermal-chemical co-therapy provides new ideas for the treatment of cancer. However, the harsh photothermal temperature hinders the clinical development of photothermal therapy. To ensure low-temperature photothermal-chemical combined therapy, a safe and feasible drug delivery system is highly desirable. Herein, through one step co-precipitation method, ginsenoside Rb1-based nanovehicles composed of the hydrophobic drug doxorubicin, the photochemical reagent Cypate and the heat shock protein inhibitor gambogic acid was prepared, resulting from the amphiphilicity and membrane permeability of Rb1. Encouragingly, this platform exhibited excellent biocompatibility and rapid cellular uptake, both of which led to significant and irreversible death of breast cancer cells under the trigger of short-term near-infrared light.

Ethanol Enhances Hyperthermia-Induced Cell Death in Human Leukemia Cells

Ethanol has been shown to exhibit therapeutic properties as an ablative agent alone and in combination with thermal ablation. Ethanol may also increase sensitivity of cancer cells to certain physical and chemical antitumoral agents. The aim of our study was to assess the potential influence of nontoxic concentrations of ethanol on hyperthermia therapy, an antitumoral modality that is continuously growing and that can be combined with classical chemotherapy and radiotherapy to improve their efficiency. Human leukemia cells were included as a model in the study. The results indicated that ethanol augments the cytotoxicity of hyperthermia against U937 and HL60 cells. The therapeutic benefit of the hyperthermia/ethanol combination was associated with an increase in the percentage of apoptotic cells and activation of caspases-3, -8 and -9. Apoptosis triggered either by hyperthermia or hyperthermia/ethanol was almost completely abolished by a caspase-8 specific inhibitor, indicating that this caspase plays a main role in both conditions. The role of caspase-9 in hyperthermia treated cells acquired significance whether ethanol was present during hyperthermia since the alcohol enhanced Bid cleavage, translocation of Bax from cytosol to mitochondria, release of mitochondrial apoptogenic factors, and decreased of the levels of the anti-apoptotic factor myeloid cell leukemia-1 (Mcl-1). The enhancement effect of ethanol on hyperthermia-activated cell death was associated with a reduction in the expression of HSP70, a protein known to interfere in the activation of apoptosis at different stages. Collectively, our findings suggest that ethanol could be useful as an adjuvant in hyperthermia therapy for cancer.

Mild Magnetic Hyperthermia-Activated Innate Immunity for Liver Cancer Therapy

Magnetic hyperthermia therapy (MHT) is noninvasive and features excellent tissue penetration for deep-seated tumors, but unfortunately, it suffers the low therapeutic efficacy due to the limited magneto-thermal efficiency and insufficient intratumor accumulation of conventional intravenous-injected magnetic nanoparticles, which are actually mostly sequestered by the mononuclear phagocyte system, especially the liver. Such a disadvantageous characteristic of preferential liver uptake is here exploited, for the first time as far as we know, to treat orthotopic liver cancer by mild MHT using specially designed composite magnetic nanoparticles. A kind of core-shell-structured and Zn²⁺-doped Zn-CoFe₂O₄@Zn-MnFe₂O₄ superparamagnetic nanoparticles (ZCMF) has been synthesized which exhibits excellent and highly controllable magnetic hyperthermia performance owing to an exchange-coupled magnetism between the core and shell, and Zn²⁺ doping. The controllable mild MHT at 43-44 °C based on ZCMF demonstrates almost complete inhibition of liver cancer cell proliferation and tumor growth, which is associated with the suppression of heat shock protein 70 (HSP70) expression. More importantly, the mild MHT-treated liver cancer cells are capable of activating natural killer (NK) cells by dramatically upregulating the expression of UL16-binding proteins (ULBPs), ligands of natural killer group 2 member D (NKG2D). As a result, the growth of both xenograft tumors and orthotopic liver tumors were almost completely suppressed under mild MHT via induced NK-cell-related antitumor immunity in vivo. This work not only evidences the great potential of mild MHT but also reveals the underlying immunity activation mechanism in liver cancer treatment by mild MHT.

Early heat exposure effect on the heat shock proteins in broilers under acute heat stress

The effects of early heat conditioning on the acute heat stress response in broilers were investigated via the growth performance, dopamine, serotonin, and corticosterone and the expression of heat shock proteins (HSP) and heat shock factors. One-day-old chicks (n = 144) were divided into 3 groups in a 35-d experiment (48 chicks per each group). Group 1 (C) was treated with an optimum temperature, group 2 (CH) was treated with 40°C ± 1°C on day 35 (5 h), and group 3 (HH) was treated with 40°C ± 1°C on day 5 (24 h) and day 35 (5 h). On day 7, the body weight gain was lower (P < 0.05) in HH than in C and CH. On day 35, the heat-treated groups (CH and HH) had lower weight gains than the C group (P < 0.05), whereas the feed conversion ratio was lower in HH (P < 0.05). Serum corticosterone was higher in CH than in C, but HH and C did not differ (P < 0.05). Liver HSP70 protein expression was higher in CH than HH and C (P < 0.05), which did not differ, and HSP40 protein expression was higher in CH than C (P < 0.05). These results suggest that early heat conditioning may reduce acute heat stress on broiler.

Quantifying cell death induced by doxorubicin, hyperthermia or HIFU ablation with flow cytometry

Triggered release and targeted drug delivery of potent anti-cancer agents using hyperthermia-mediated focused-ultrasound (FUS) is gaining momentum in the clinical setting. In early phase studies, tissue biopsy samples may be harvested to assess drug delivery efficacy and demonstrate lack of instantaneous cell death due to FUS exposure. We present an optimised tissue cell recovery method and a cell viability assay, compatible with intra-cellular doxorubicin. Flow cytometry was used to determine levels of cell death with suspensions comprised of: (i) HT29 cell line exposed to hyperthermia (30 min at 47 °C) and/or doxorubicin, or ex-vivo bovine liver tissue exposed to (ii) hyperthermia (up to 2 h at 45 °C), or (iii) ablative high intensity FUS (HIFU). Flow cytometric analysis revealed maximal cell death in HT29 receiving both heat and doxorubicin insults and increases in both cell granularity (p < 0.01) and cell death (p < 0.01) in cells recovered from ex-vivo liver tissue exposed to hyperthermia and high pressures of HIFU (8.2 MPa peak-to-peak free-field at 1 MHz) relative to controls. Ex-vivo results were validated with microscopy using pan-cytokeratin stain. This rapid, sensitive and highly quantitative cell-viability method is applicable to the small masses of liver tissue typically recovered from a standard core biopsy (5-20 mg) and may be applied to tissues of other histological origins including immunostaining.

Polydopamine-based nanomaterials and their potentials in advanced drug delivery and therapy

Polydopamine (PDA) has shown great potentials in biomedical fields due largely to its unique physicochemical properties, including high photothermal transfer efficiency, excellent drug binding capacity, versatile adhesion ability, sensitive pH responsibility and great biocompatibility and biodegradability. These properties confer PDA-based nanoparticles the potentials either as the drug carriers for advanced drug delivery or as the bioactive agents for photothermal therapy, imaging and biosensing. This review aims to provide a comprehensive understanding of PDA, its polymerization mechanisms and the potentials of PDA-based nano-systems in treating various diseases, including cancer, diabetes, inflammation, bacterial infection and Parkinson's disease. In addition, the concerns of PDA in biomedical use are also discussed.

Intratumoral hyperthermic chemotherapy injection in peripheral non-small cell lung cancer

Background

Intratumoral chemotherapy (ITC) has been used by many groups; the combination of heat and cytotoxic drugs increases the ability to destroy the malignant cells. The aim of this study was to assess the efficacy and safety of percutaneous injection of hyperthermic chemotherapy in conjunction with systemic chemotherapy as a palliative management of peripheral inoperable non-small cell lung cancer (NSCLC) compared to conventional systemic chemotherapy.

Results

There was a statistically significant improvement in quality of life score in group A and B, but deterioration in group C after 6 months. As regards radiology, after 6 months in group A, one patient (10%) showed complete response, 6 patients (60%) showed partial response, one patient (10%) stable response, and two patients (20%) showed progression; in group B, 6 patients (60%) showed partial response, two patients (20%) showed stable response, and two patients (20%) showed progression; and in group C, 7 patients (70%) showed progression, two patients (20%) showed partial response, and one patient (10%) showed stable response. There were few controllable complications. Median survival in group A was 16 months, in group B was 15 months, and in group C was 8 months.

Conclusion

Intratumoral hyperthermic chemotherapy is a promising, effective, harmless palliative therapy for inoperable peripheral NSCLC.

Molecular Chaperone HSP70 and Key Regulators of Apoptosis - A Review

Identified as a molecular chaperone constitutively being synthesized due to enhanced elevated temperature change, this heat shock protein HSP70 has shown to be intimately involved in many protein biogenesis, facilitating the synthesis and folding of proteins and trafficking of nascent peptides during cell growth. HSP70 also plays a vital role in protein assembly, regulation and interaction with a wide variety of proteins. Stress-induced cell death is under the control of the Bcl-2 family of apoptotic regulators and display either pro-apoptotic or anti-apoptotic activities. Subjected to stress conditions such as heat shock, cells have been reported to express elevated expressions of HSP70. Moreover, this molecular chaperon has shown to act at multiple levels to suppress stressed-induced apoptotic signals of some Bcl-2 members by repairing, re-synthesizing damaged proteins, and stabilizing unfolded proteins. Therefore, HSP70 synthesis can act as an essential recovery mode for cellular survival and adaptation during lethal conditions.

Functionalized boron nanosheets as an intelligent nanoplatform for synergistic low-temperature photothermal therapy and chemotherapy

In this work, an innovative boron-based multifunctional nanoplatform was developed for synergistic chemotherapy/low temperature photothermal therapy (PTT). This platform is functionalized with a cRGD peptide to allow the targeting of αvβ3 integrin, which is over-expressed in the cells of tumors. The nanoparticles were further loaded with the chemotherapeutic drug doxorubicin (DOX) and a heat shock protein inhibitor (17AAG), and high loading capacities for both DOX (603 mg g-1 B-PEG-cRGD) and 17AAG (417 mg g-1) were obtained. The resultant DOX-17AAG@B-PEG-cRGD system shows both pH-controlled and near-infrared (NIR)-induced DOX and 17AAG release. It also provides significantly enhanced cellular uptake in cancerous cells over healthy cells. The presence of 17AAG allows low-temperature PTT to be combined with chemotherapy with DOX, resulting in highly effective anti-cancer activity. This has been confirmed by both in vitro assays and using an in vivo murine cancer model. It is expected that such a multifunctional nanoplatform can serve as a promising candidate for cancer therapy.

Hyperthermia treatment advances for brain tumors

Hyperthermia therapy (HT) of cancer is a well-known treatment approach. With the advent of new technologies, HT approaches are now important for the treatment of brain tumors. We review current clinical applications of HT in neuro-oncology and ongoing preclinical research aiming to advance HT approaches to clinical practice. Laser interstitial thermal therapy (LITT) is currently the most widely utilized thermal ablation approach in clinical practice mainly for the treatment of recurrent or deep-seated tumors in the brain. Magnetic hyperthermia therapy (MHT), which relies on the use of magnetic nanoparticles (MNPs) and alternating magnetic fields (AMFs), is a new quite promising HT treatment approach for brain tumors. Initial MHT clinical studies in combination with fractionated radiation therapy (RT) in patients have been completed in Europe with encouraging results. Another combination treatment with HT that warrants further investigation is immunotherapy. HT approaches for brain tumors will continue to a play an important role in neuro-oncology.

Understanding the mechanisms of silica nanoparticles for nanomedicine

As a consequence of recent progression in biomedicine and nanotechnology, nanomedicine has emerged rapidly as a new discipline with extensive application of nanomaterials in biology, medicine, and pharmacology. Among the various nanomaterials, silica nanoparticles (SNPs) are particularly promising in nanomedicine applications due to their large specific surface area, adjustable pore size, facile surface modification, and excellent biocompatibility. This paper reviews the synthesis of SNPs and their recent usage in drug delivery, biomedical imaging, photodynamic and photothermal therapy, and other applications. In addition, the possible adverse effects of SNPs in nanomedicine applications are reviewed from reported in vitro and in vivo studies. Finally, the potential opportunities and challenges for the future use of SNPs are discussed.

This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Chronic heat treatment positively impacts metabolic profile of ovariectomized rats: association with heat shock response pathways

Low estrogen levels may predispose women to increased bodyweight and dyslipidemia. Previous studies from our laboratory suggest an involvement of depressed heat shock response (HSR) in this scenario because estrogen potently stimulates HSR. As heat treatment induces the expression of the anti-inflammatory heat shock proteins of the 70-kDa family (HSP70) and its accompanying HSR, we aimed to investigate whether chronic heat treatment promotes beneficial effects on biometric, lipid profile, oxidative stress, and HSR in ovariectomized rats. Wistar adult female rats (n = 32) were divided into four groups: control (C, n = 7), ovariectomized (OVX, n = 9), heat-treated (HT, n = 9), and heat-treated ovariectomized rats (OVX+HT, n = 7). HT and OVX+HT rats were anesthetized and submitted to heat treatment (once a week for 12 weeks) in a water bath (41 °C) to increase rats' rectal temperature up to 41 °C for 15 min, while C and OVX animals were submitted to a 36 °C water bath. HT attenuated the weight gain induced by OVX and increased HDL cholesterol and triglyceride serum levels. Also, OVX rats showed increased total cholesterol and LDL cholesterol levels that were not influenced by HT. Interestingly, it was found that an overall trend for HT to decrease tissue catalase and superoxide dismutase antioxidant activities was paralleled by a decrease in malondialdehyde levels (indicative of lower lipoperoxidation), especially in the skeletal muscle. Surprisingly, OVX was not able to depress intracellular HSP70 expression in the skeletal muscle, as expected, and this remained unchanged with HT. However, chronic HT did enhance intracellular HSP70 contents in white adipose tissue of OVX animals. As both glucose and insulin tolerance tests were not affected by OVX, which was not modified by HT, we suppose that estrogen absence alone is not sufficient to determine a state of insulin resistance associated with low intramuscular HSP70 content.

HIKESHI silencing can enhance mild hyperthermia sensitivity in human oral squamous cell carcinoma HSC‑3 cells

Hyperthermia (HT) is considered to be of value as a treatment modality in various cancers. However, the acquisition of thermotolerance in cancer cells due to the induction of heat shock proteins (HSPs) makes HT less effective. Recent findings have indicated that heat shock protein nuclear import factor hikeshi (HIKESHI), also referred to as C11orf73, acts as a nuclear import carrier of Hsp70 under heat stress conditions. The aim of the present study was to determine whether knockdown (KD) of HIKESHI by small interfering RNA (siRNA) can potentiate mild HT (MHT) sensitivity in human oral squamous cell carcinoma (OSCC) HSC‑3 cells. The mRNA and protein expression of HIKESHI was found to be markedly suppressed in HSC‑3 cells treated with siRNA for HIKESHI (siHIKE). Silencing HIKESHI significantly decreased the cell viability under MHT conditions (42˚C for 90 min). Immunocytochemical and western blot analyses clearly demonstrated that Hsp70 protein translocated from the cytoplasm to the nucleus under MHT conditions, and this translocation was significantly inhibited in cells treated with siHIKE. Treatment of the cells with MHT transiently increased the phosphorylation level of extracellular signal‑regulated kinase (ERK)2. Furthermore, the phosphorylation was sustained in HIKESHI‑KD cells under MHT conditions, and this sustained phosphorylation was abolished by pretreatment with U0126, an inhibitor of mitogen‑activated protein kinase/ERK. In addition, U0126 significantly decreased the viability of cells treated with the combination of HIKESHI‑KD and MHT. The data of the present study suggest that HIKESHI silencing enhanced the sensitivity of human OSCC HSC‑3 cells to MHT.

Histopathological evaluation of prostate specimens after thermal ablation may be confounded by the presence of thermally-fixed cells

Purpose: Prostate cancer can be eradicated with heat exposure. However, high and rapid temperature elevations may cause thermofixation giving the appearance of viable tissue. The purpose was to characterize the immunoprofile and evaluate the viability of prostate regions with suspected thermofixation. Methods and materials: A prospective, ethics-approved and registered study (NCT03350529) enrolled six patients with MRI-visible, biopsy-concordant prostate cancer to undergo lesion-targeted MRI-guided transurethral ultrasound ablation (TULSA) followed by radical prostatectomy at 3 weeks, to evaluate the accuracy and efficacy of TULSA with whole-mount histology as a reference standard. If ambiguity about complete necrosis within the ablated region remained after hematoxylin-eosin staining, viability was assessed by immunohistochemistry. Treatment day MRI-thermometry and 3-week contrast-enhanced MRI post-TULSA were examined to assess ablation success and correlation with histopathology. Results: One patient presented with an apparently viable subregion inside the ablated area, surrounded by necrosis on H&E staining, located where temperature was highest on MRI-thermometry and tissues completely devascularized on MRI. Immunoprofile of the apparently viable tissue revealed changes in staining patterns suggesting thermofixation; the most significant evidence was the negative cytokeratin 8 staining detected with Cam5.2 antibody. A comprehensive literature review supports these observations of thermofixation with similar findings in prostate and other tissues. Conclusion: Thermally-fixed cells can sustain morphology on H&E staining. Misinterpretation of treatment failure may occur, if this phenomenon is not recognized and immunohistochemistry performed. Based on the previous literature and the current study, Cam5.2 staining for cytokeratin 8 appears to be a practical and reliable tool for distinguishing thermally-fixed from viable cells.

Pulsed high-power microwaves do not impair the functions of skin normal and cancer cells in vitro: A short-term biological evaluation

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Pulsed high power microwave (MW) at a frequency 3.5 GHz was generated.

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MW did not induce cell death in skin fibroblast normal cells and melanoma cells.

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MW did not alter the morphology of melanoma cells.

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Gene expression related to ATP synthesis and proliferation can get altered by MW.

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MW selectively stimulated viability and proliferation of only melanoma cells.

Over the past few decades, microwave (MW) radiation has been widely used, and its biological effects have been extensively investigated. However, the effect of MW radiation on human skin biology is not well understood. We study the effects of pulsed high-power microwaves (HPMs) on melanoma (G361 and SK-Mel-31) and normal human dermal fibroblast (NHDF) cells. A pulsed power generator (Chundoong) was used to generate pulsed HPMs (dominant frequency: 3.5 GHz). For treatment 1, 5, 15, and 45 shots are given to cells in which the electromagnetic energy of 0.6 J was delivered to the cells at each trigger shot. Cell viability, proliferation rate, apoptosis, cell death, metabolic activity, and oxygen-free radical regulation were evaluated after the MW exposure at low and high doses. MW exposure increased the viabilities and proliferation rates of both melanoma cell lines in a dose-dependent manner, while no significant effects on the fibroblast cells were observed. We found an elevated level of ATP and mitochondrial activity in melanoma cells. Also, it was observed that MW exposure did not affect cell death in melanoma and fibroblast cells. A polymerase chain reaction analysis indicated that the MWs induced dose-dependent proliferation markers without affecting the cell cycle and apoptotic genes in the melanoma cells. Our findings show the differential effects of the MW radiation on the melanoma cells, compared to those on the fibroblast cells.

Millimeter-wave pulsed heating in vitro: cell mortality and heat shock response

Millimeter wave (MMW)-induced heating represents a promising alternative for non-invasive hyperthermia of superficial skin cancer, such as melanoma. Pulsed MMW-induced heating of tumors allows for reaching high peak temperatures without overheating surrounding tissues. Herein, for the first time, we evaluate apoptotic and heat shock responses of melanoma cells exposed in vitro to continuous (CW) or pulsed-wave (PW) amplitude-modulated MMW at 58.4 GHz with the same average temperature rise. Using an ad hoc exposure system, we generated 90 min pulse train with 1.5 s pulse duration, period of 20 s, amplitude of 10 °C, and steady-state temperature at the level of cells of 49.2 °C. The activation of Caspase-3 and phosphorylation of HSP27 were investigated using fluorescence microscopy to monitor the spatial variation of cellular response. Our results demonstrate that, under the considered exposure conditions, Caspase-3 activation was almost 5 times greater following PW exposure compared to CW. The relationship between the PW-induced cellular response and SAR-dependent temperature rise was non-linear. Phosphorylation of HSP27 was 58% stronger for PW compared to CW. It exhibits a plateau for the peak temperature ranging from 47.7 to 49.2 °C. Our results provide an insight into understanding of the cellular response to MMW-induced pulsed heating.