Heat shock protein 90 inhibitor enhances apoptosis by inhibiting the AKT pathway in thermal-stimulated SK-MEL-2 human melanoma cell line

Clinical implications of heat shock protein 70 in oral carcinogenesis and prediction of progression and recurrence in oral squamous cell carcinoma patients: a retrospective clinicopathological study

BACKGROUND

Oral cancer is a common cause of death worldwide. The search for novel biomarkers for oral cancer is an ongoing struggle. Prognostic biomarkers are of great importance in diagnosis, and prediction of the cancer outcome. There are several disagreements in oral cancer studies over the role of heat shock proteins as prognostic markers. The current study investigated HSP70 expression in diverse tissues ranging from normal oral mucosa to dysplastic oral epithelium and oral squamous cell carcinoma to determine its role in oral carcinogenesis. Moreover, HSP70 was evaluated concerning different prognostic parameters to determine its capability in predicting cancer progression. Recurrence of tumor was recorded, and patients` disease-free survival was calculated and analyzed considering HSP70 expression to determine the potential utility of HSP70 immuno-expression in predicting recurrence.

METHODS

A retrospective study was accomplished on 50 cases of OSCC. Biopsies from the cancerous tissue, the free surgical margin, and the normal oral mucosa were used. The grading of dysplastic epithelium and OSCCs followed the criteria of WHO classification (2017). The clinicopathological and follow-up records for each patient were retrieved. Pearson's Chi-square test, one-way ANOVA, and post hoc tests were used to analyze the variance of HSP70 immuno-expression concerning different parameters. The Kaplan-Meier method was used to compute and visualize disease-free survival, and the log-rank test was used to analyze the data. With Cox regression, univariate and multivariate survival analyses were run. A P-value of 0.05 or less was regarded as statistically significant.

RESULTS

A significant increased expression of HSP70 was observed as the tissue progressed from normal to dysplastic epithelium, and carcinoma (P = 0.000). HSP70 revealed a significant increased expression by progression from mild to severe dysplasia (P = 0.023), and also from well to moderately and poorly differentiated carcinoma (P = 0.000). High HSP70 immuno-expression was significantly associated with progression of OSCC; large-sized tumors (P = 0.002), advanced TNM clinical stages (P = 0.001), positive nodal involvement (P = 0.001), presence of recurrence (P = .008), and reduced DFS (P = 0.014).

CONCLUSION

HSP70 has a crucial contribution to oral carcinogenesis, and its immune-expression could potentially be used as predictor of progression and recurrence of OSCC patients.

TRIAL REGISTRATION

Retrospectively registered.

Adverse Effects of High Temperature On Mammary Alveolar Development In Vitro

In the mammary glands during pregnancy, the alveolar buds are first branched from the mammary ducts after which they form the alveolar luminal structure for milk production postparturition. Body temperature could increase for several reasons, such as infectious disease and heat stress. We have previously reported that high temperature adversely effects on the lactation capacity of mouse mammary epithelial cells (MECs). However, it remains unclear how high temperature influences mammary morophogenesis during pregnancy. In this study, we investigated the effects of high temperature on this mammary alveolar development process using two types of culture models including embedded organoids of MECs in Matrigel; these models reproduced mammary alveolar bud induction and alveolar luminal formation. Results showed that a culture temperature of 41 °C repressed alveolar bud induction and inhibited alveolar luminal formation. In addition, the treatment at 41 °C decreased the number of proliferating mammary epithelial cells but did not affect cell migration. Levels of phosphorylated Akt, -ERK1/2, -HSP90, and -HSP27 were increased in organoids cultured at 41 °C. The specific inhibitors of HSP90 and HSP27 exacerbated the disruption of organoids at 41 °C but not at 37 °C. Furthermore, the organoids precultured at 37 and 41 °C in the alveolar luminal formation model showed differences in the expression levels of caseins and tight junction proteins, which express in MECs in lactating mammary glands, after induction of MEC differentiation by prolactin and dexamethasone treatment in vitro. These results suggest that elevated temperature directly hinders mammary alveolar development; however, heat shock proteins may mitigate the adverse effects of high temperatures.

Zinc Alleviates Arsenic-Induced Inflammation and Apoptosis in the Head Kidney of Common Carp by Inhibiting Oxidative Stress and Endoplasmic Reticulum Stress

Arsenic (As) pollution is ubiquitous in water, which shows immunotoxicity to aquatic organisms. As an indispensable regulator of gene transcription and enzymatic modification, zinc (Zn) may play a preventive and therapeutic effect on As toxicity. The purpose of this study was to investigate the interactions of As and Zn on the head kidney of common carp Cyprinus carpio. Herein the carp were treated alone or in combination with waterborne As³⁺ (2.83 mg/L) and/or Zn²⁺ (1 mg/L). Results suggested a head kidney-toxic effect of As exposure, which was manifested by the histopathological damage of the head kidney, elevation of nuclear translocation of pro-inflammatory nuclear factor-kappa light chain enhancer of B cells (NF-κB), and blockage of the anti-oxidative nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. The global activation of three endoplasmic reticulum (ER) stress pathways led to the execution of programmed cell death, including ER apoptosis mediated by C/EBP-homologous protein (CHOP), death receptor-mediated exogenous cell apoptosis, and the endogenous apoptosis executed by Caspases9. The combined application of Zn can significantly improve the histopathological damage of the head kidney, the imbalance of the antioxidant system, and the apoptosis outcomes due to ER stress. In conclusion, this study indicates that Zn has an antagonistic effect on the head kidney injury of common carp induced by sub-chronic As exposure. The results of this study provide basic data for the risk assessment of As accumulation in an aquatic environment and a reference for the use of Zn preparation in aquaculture.

Mammalian AKT, the Emerging Roles on Mitochondrial Function in Diseases

Mitochondrial dysfunction may play a crucial role in various diseases due to its roles in the regulation of energy production and cellular metabolism. Serine/threonine kinase (AKT) is a highly recognized antioxidant, immunomodulatory, anti-proliferation, and endocrine modulatory molecule. Interestingly, increasing studies have revealed that AKT can modulate mitochondria-mediated apoptosis, redox states, dynamic balance, autophagy, and metabolism. AKT thus plays multifaceted roles in mitochondrial function and is involved in the modulation of mitochondria-related diseases. This paper reviews the protective effects of AKT and its potential mechanisms of action in relation to mitochondrial function in various diseases.

The Role of Senescent Cells in Acquired Drug Resistance and Secondary Cancer in BRAFi-Treated Melanoma

Simple Summary

Advances in melanoma treatment include v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors that target the predominant oncogenic mutation found in malignant melanoma. Despite initial success of the BRAF inhibitor (BRAFi) therapies, resistance and secondary cancer often occur. Mechanisms of resistance and secondary cancer rely on upregulation of pro-survival pathways that circumvent senescence. The repeated identification of a cellular senescent phenotype throughout melanoma progression demonstrates the contribution of senescent cells in resistance and secondary cancer development. Incorporating senotherapeutics in melanoma treatment may offer a novel approach for potentially improving clinical outcome.

Abstract

BRAF is the most common gene mutated in malignant melanoma, and predominately it is a missense mutation of codon 600 in the kinase domain. This oncogenic BRAF missense mutation results in constitutive activation of the mitogen-activate protein kinase (MAPK) pro-survival pathway. Several BRAF inhibitors (BRAFi) have been developed to specifically inhibit BRAF^V600 mutations that improve melanoma survival, but resistance and secondary cancer often occur. Causal mechanisms of BRAFi-induced secondary cancer and resistance have been identified through upregulation of MAPK and alternate pro-survival pathways. In addition, overriding of cellular senescence is observed throughout the progression of disease from benign nevi to malignant melanoma. In this review, we discuss melanoma BRAF mutations, the genetic mechanism of BRAFi resistance, and the evidence supporting the role of senescent cells in melanoma disease progression, drug resistance and secondary cancer. We further highlight the potential benefit of targeting senescent cells with senotherapeutics as adjuvant therapy in combating melanoma.

Inhibitors of HSP90 in melanoma

HSP90 (heat shock protein 90) is an ATP-dependent molecular chaperone involved in a proper folding and maturation of hundreds of proteins. HSP90 is abundantly expressed in cancer, including melanoma. HSP90 client proteins are the key oncoproteins of several signaling pathways controlling melanoma development, progression and response to therapy. A number of natural and synthetic compounds of different chemical structures and binding sites within HSP90 have been identified as selective HSP90 inhibitors. The majority of HSP90-targeting agents affect N-terminal ATPase activity of HSP90. In contrast to N-terminal inhibitors, agents interacting with the middle and C-terminal domains of HSP90 do not induce HSP70-dependent cytoprotective response. Several inhibitors of HSP90 were tested against melanoma in pre-clinical studies and clinical trials, providing evidence that these agents can be considered either as single or complementary therapeutic strategy. This review summarizes current knowledge on the role of HSP90 protein in cancer with focus on melanoma, and provides an overview of structurally different HSP90 inhibitors that are considered as potential therapeutics for melanoma treatment.

Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy

Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.

Mild microwave ablation combined with HSP90 and TGF‑β1 inhibitors enhances the therapeutic effect on osteosarcoma

Osteosarcoma is the most common malignant bone tumour and the second leading cause of cancer-related death in children and adolescents. Microwave ablation has an excellent therapeutic effect on bone tumours by instantaneously increasing the temperature in the tumour; however, there is a risk of damaging the surrounding healthy tissues by exposure to a high temperature when the treatment power is too large. In the present study, two anti-tumour reagents, a heat shock protein 90 (HSP90) inhibitor (PF-04929113) and a transforming growth factor-β1 (TGF-β1) inhibitor (SB-525334) were employed to enhance the therapeutic effect of mild-power microwave ablation. It was revealed that microwaving to 48°C combined with HSP90 and TGF-β1 inhibitors significantly increased the apoptotic rate of VX2 cells. The same results were observed during in vivo experiments using New Zealand rabbits to model osteosarcoma. In addition, the results indicated that the expression of cytochrome c, caspase-3 and caspase-9 were upregulated in response to the treatment, which indicated that the mitochondrial apoptotic signalling pathway had been activated. These findings may provide a novel strategy for the development of microwave ablation in osteosarcoma treatment, which could effectively kill tumour cells without damaging the surrounding normal tissues.

The Role of Erythroid Differentiation Regulator 1 (ERDR1) in the Control of Proliferation and Photodynamic Therapy (PDT) Response

Erythroid differentiation regulator 1 (ERDR1) was newly identified as a secreted protein that plays an essential role in maintaining cell growth homeostasis. ERDR1 enhances apoptosis at high cell densities, leading to the inhibition of cell survival. Exogenous ERDR1 treatment decreases cancer cell proliferation and tumor growth as a result of increased apoptosis via the regulation of apoptosis-related gene expression. Moreover, ERDR1 plays a pivotal role in skin diseases; ERDR1 expression in actinic keratosis (AK) is negatively correlated with the increase in apoptosis. Because of its high specificity and efficiency, photodynamic therapy (PDT) is a common therapy for patients with various skin diseases, including cancer. Many studies indicate that apoptosis is mainly induced by PDT treatment. As an apoptosis inducer, the recovery of the ERDR1 expression after PDT is correlated with good therapeutic outcomes. Here, we review recent findings that highlight the function of ERDR1 in the control of apoptosis. Thus, ERDR1 may have a role in the apoptosis regulation of target cells in the lesions, as the recovery of its expression after PDT is correlated with good therapeutic outcomes.

Immunomorphological Pattern of Molecular Chaperones in Normal and Pathological Thyroid Tissues and Circulating Exosomes: Potential Use in Clinics

The thyroid is a major component of the endocrine system and its pathology can cause serious diseases, e.g., papillary carcinoma (PC). However, the carcinogenic mechanisms are poorly understood and clinical useful biomarkers are scarce. Therefore, we determined if there are quantitative patterns of molecular chaperones in the tumor tissue and circulating exosomes that may be useful in diagnosis and provide clues on their participation in carcinogenesis. Hsp27, Hsp60, Hsp70, and Hsp90 were quantified by immunohistochemistry in PC, benign goiter (BG), and normal peritumoral tissue (PT). The same chaperones were assessed in plasma exosomes from PC and BG patients before and after ablative surgery, using Western blotting. Hsp27, Hsp60, and Hsp90 were increased in PC in comparison with PT and BG but no differences were found for Hsp70. Similarly, exosomal levels of Hsp27, Hsp60, and Hsp90 were higher in PC than in BG, and those in PC were higher before ablative surgery than after it. Hsp27, Hsp60, and Hsp90 show distinctive quantitative patterns in thyroid tissue and circulating exosomes in PC as compared with BG, suggesting some implication in the carcinogenesis of these chaperones and indicating their potential as biomarkers for clinical applications.

Increased expression of heat shock protein (HSP) 10 and HSP70 correlates with poor prognosis of nasopharyngeal carcinoma

BACKGROUND

Heat shock proteins (HSPs) are a large family of chaperones implicating in occurrence and progression of tumor. In our previous study, we found HSP10 correlates with poor prognosis of oral squamous cell carcinoma and astrocytoma. HSP70 is also an important part of this family and whether the alterations of HSP10 and HSP70 expression and their common expression correlates with carcinogenesis and progression of nasopharyngeal carcinoma (NPC) has not been reported.

METHOD

In this study, we investigate the correlation between the expression of HSP10 and HSP70 and clinicopathological characteristics in NPC by immunohistochemistry (IHC).

RESULTS

Results indicated that positive expression of HSP10 and HSP70 was higher in NPC tissues (both P<0.001). Positive expression of HSP10 and HSP70 proteins, and common positive expression of the two HSPs analyzed in advanced clinical stages were higher than that in early clinical stages (All P<0.05). There was significantly higher expression of HSP10, HSP70, and common expression in NPC with LNM (lymph node metastasis) compared with NPC without LNM (All P<0.05). Interestingly, positive expression of HSP10 and HSP70 proteins and common expression had an evidently inverse correlation with survival status (All P<0.05). Spearman's correlation analysis showed expression of HSP10 was positively associated with HSP70 (r=0.407, P<0 0.001). Kaplan-Meier analysis showed that the overall survival rates for NPC patients with positive expression of HSP10 and HSP70 and common expression were significantly lower than these patients with negative expression (All P<0.05). Furthermore, positive expression of HSP10 and HSP70 proteins was identified as independent poor prognostic factors for NPC patients (both P<0.05) by Cox regression analysis.

CONCLUSION

 In conclusion, HSP10 and HSP70 can serve as the poor prognostic factors for NPC patients.

Blockage of transferred exosome-shuttled miR-494 inhibits melanoma growth and metastasis

There is emerging evidence of bioactive material transport by exosomes in melanoma. However, the functions of exosome content underlying such cancer progression remain largely unknown. We aimed at determining whether exosome secretion contributes to cellular microRNA-494 (miR-494) loss and investigated the roles of miR-494 in melanoma progression. The exosomes from blood serum and cell culture conditioned media were separated by ultracentrifugation. A short hairpin RNA was used to silence rab27a for inhibiting exosome release. To address the functional role of exosomal miR-494, we assessed cell proliferation, migration, invasion capabilities, and cell apoptosis. Finally, subcutaneous xenograft and lung-metastasis models were constructed to determine the effect of exosomal miR-494 in vivo. Based on long noncoding RNA microarray analysis of melanocyte and melanoma-derived exosomes from the Gene Expression Omnibus database, we discovered that miR-494 was enriched in melanoma-derived exosomes. And miR-494 was increased in exosomes secreted from melanoma patients' serum and A375 cells. Rab27a depletion reduced exosome secretion and rescued the abundance of cellular miR-494. Functional studies revealed that knockdown of rab27a and subsequent accumulation of miR-494 significantly suppressed the malignant phenotypes of melanoma cells via inducing cell apoptosis. Nude mice experiments confirmed that tumor growth and metastasis were suppressed by increasing miR-494 accumulation after rab27a depletion. In conclusion, blocking transferred exosome-shuttled miR-494 is a potential therapeutic option for melanoma.

Vorapaxar stabilizes permeability of the endothelial barrier under cholesterol stimulation via the AKT/JNK and NF‑κB signaling pathways

Atherosclerosis (AS) is an inflammatory disease that occurs in the arterial wall and is characterized by progressive lipid accumulation within the intima of large arteries, leading to the dysfunction of endothelial cells and further destruction of the endothelial barrier and vascular tone. Arterial intima injury accelerates the adhesion and activation of platelets at the injury site. The activation of platelets results in the secretion of growth factors, leading to the migration and proliferation of vascular smooth muscle cells (VSMCs), promoting the formation of plaque, resulting in the formation of thrombus. The present study found that vorapaxar could alleviate the inflammatory response induced by a high concentration of cholesterol stimulation and increase the release of nitric oxide (NO) via the protein kinase B (AKT) signaling pathway and regulation of the intracellular concentration of Ca2+ ([Ca2+]i). We also found that vorapaxar could reduce the damage of DNA caused by cholesterol stimulation and regulate the cell cycle via the AKT/JNK signaling pathway and its downstream molecules glycogen synthase kinase 3β (GSK‑3β) and connexin 43, maintaining the integrity of the endothelial barrier and proliferation of endothelial cells, serving a protective role in endothelial cells.