Anticancer activity of methylene blue via inhibition of heat shock protein 70

Toxic Effects of Penetrating Cations

As mitochondria are negatively charged organelles, penetrating cations are used as parts of chimeric molecules to deliver specific compounds into mitochondria. In other words, they are used as electrophilic carriers for such chemical moieties as antioxidants, dyes, etc., to transfer them inside mitochondria. However, unmodified penetrating cations affect different aspects of cellular physiology as well. In this review, we have attempted to summarise the data about the side effects of commonly used natural (e.g., berberine) and artificial (e.g., tetraphenylphosphonium, rhodamine, methylene blue) penetrating cations on cellular physiology. For instance, it was shown that such types of molecules can (1) facilitate proton transport across membranes; (2) react with redox groups of the respiratory chain; (3) induce DNA damage; (4) interfere with pleiotropic drug resistance; (5) disturb membrane integrity; and (6) inhibit enzymes. Also, the products of the biodegradation of penetrating cations can be toxic. As penetrating cations accumulate in mitochondria, their toxicity is mostly due to mitochondrial damage. Mitochondria from certain types of cancer cells appear to be especially sensitive to penetrating cations. Here, we discuss the molecular mechanisms of the toxic effects and the anti-cancer activity of penetrating cations.

Synthetic Small Molecule Modulators of Hsp70 and Hsp40 Chaperones as Promising Anticancer Agents

A class of chaperones dubbed heat shock protein 70 (Hsp70) possesses high relevance in cancer diseases due to its cooperative activity with the well-established anticancer target Hsp90. However, Hsp70 is closely connected with a smaller heat shock protein, Hsp40, forming a formidable Hsp70-Hsp40 axis in various cancers, which serves as a suitable target for anticancer drug design. This review summarizes the current state and the recent developments in the field of (semi-)synthetic small molecule inhibitors directed against Hsp70 and Hsp40. The medicinal chemistry and anticancer potential of pertinent inhibitors are discussed. Since Hsp90 inhibitors have entered clinical trials but have exhibited severe adverse effects and drug resistance formation, potent Hsp70 and Hsp40 inhibitors may play a significant role in overcoming the drawbacks of Hsp90 inhibitors and other approved anticancer drugs.

Synergic Thermo- and pH-Sensitive Hybrid Microgels Loaded with Fluorescent Dyes and Ultrasmall Gold Nanoparticles for Photoacoustic Imaging and Photothermal Therapy

Smart microgels (μGels) made of polymeric particles doped with inorganic nanoparticles have emerged recently as promising multifunctional materials for nanomedicine applications. However, the synthesis of these hybrid materials is still a challenging task with the necessity to control several features, such as particle sizes and doping levels, in order to tailor their final properties in relation to the targeted application. We report herein an innovative modular strategy to achieve the rational design of well-defined and densely filled hybrid particles. It is based on the assembly of the different building blocks, i.e., μGels, dyes, and small gold nanoparticles (<4 nm), and the tuning of nanoparticle loading within the polymer matrix through successive incubation steps. The characterization of the final hybrid networks using UV-vis absorption, fluorescence, transmission electron microscopy, dynamic light scattering, and small-angle X-ray scattering revealed that they uniquely combine the properties of hydrogel particles, including high loading capacity and stimuli-responsive behavior, the photoluminescent properties of dyes (rhodamine 6G, methylene blue and cyanine 7.5), and the features of gold nanoparticle assembly. Interestingly, in response to pH and temperature stimuli, the smart hybrid μGels can shrink, leading to the aggregation of the gold nanoparticles trapped inside the polymer matrix. This stimuli-responsive behavior results in plasmon band broadening and red shift toward the near-infrared region (NIR), opening promising prospects in biomedical science. Particularly, the potential of these smart hybrid nanoplatforms for photoactivated hyperthermia, photoacoustic imaging, cellular internalization, intracellular imaging, and photothermal therapy was assessed, demonstrating well controlled multimodal opportunities for theranostics.

Drug repurposing: An emerging strategy in alleviating skin cancer

Skin cancer is one of the most common forms of cancer. Several million people are estimated to have affected with this condition worldwide. Skin cancer generally includes melanoma and non-melanoma with the former being the most dangerous. Chemotherapy has been one of the key therapeutic strategies employed in the treatment of skin cancer, especially in advanced stages of the disease. It could be also used as an adjuvant with other treatment modalities depending on the type of skin cancer. However, there are several shortfalls associated with the use of chemotherapy such as non-selectivity, tumour resistance, life-threatening toxicities, and the exorbitant cost of medicines. Furthermore, new drug discovery is a lengthy and costly process with minimal likelihood of success. Thus, drug repurposing (DR) has emerged as a new avenue where the drug approved formerly for the treatment of one disease can be used for the treatment of another disease like cancer. This approach is greatly beneficial over the de novo approach in terms of time and cost. Moreover, there is minimal risk of failure of repurposed therapeutics in clinical trials. There are a considerable number of studies that have reported on drugs repurposed for the treatment of skin cancer. Thus, the present manuscript offers a comprehensive overview of drugs that have been investigated as repurposing candidates for the efficient treatment of skin cancers mainly melanoma and its oncogenic subtypes, and non-melanoma. The prospects of repurposing phytochemicals against skin cancer are also discussed. Furthermore, repurposed drug delivery via topical route and repurposed drugs in clinical trials are briefed. Based on the findings from the reported studies discussed in this manuscript, drug repurposing emerges to be a promising approach and thus is expected to offer efficient treatment at a reasonable cost in devitalizing skin cancer.

Histological changes of cervical tumours following Zanthoxylum acanthopodium DC treatment, and its impact on cytokine expression

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ZAM administration had no effect on the bodyweight of cervical cancer rats.

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Antioxidants found in andaliman can lower levels of MDA and serum NGAL, thereby increasing SOD activity.

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ZAM treatment can suppress the production of IL1β and TGFβ1 which promotes cancer cell growth in rats.

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ZAM administration can increase IL-10 expression in cervical cancer rats, thereby suppressing the growth of cervical cancer.

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ZAM decrease VEGFR1 serum expression and improve histology in cervical cancer rats.

Cervical cancer is the second most lethal cancer in Indonesia, behind breast cancer. One of the reasons cancer cells are difficult to treat is that the immune system is sometimes unable to recognise them as foreign. Cytokinin therapy is carried out so that the immune system can strengthen its response to cancer cells, with the aim of slowing or stopping the development of malignant cells. Zanthoxylum acanthopodium DC, also known as andaliman, is an Indonesian herb and a member of the Rutaceae family. It is rich in antioxidants and has anti-inflammatory and anti-cancer properties. The current study aimed to investigate the histological changes and changes in the expression of cytokines, such as IL-10, IL1β, VEGFR1, and TGFβ1, associated with andaliman treatment. Sample tissues and serums extracted from cervical cancer rat models were used. Rats were divided into five groups: a control group (C−), cancer model group (C+), cancer with a dose of Z. acanthopodium methanolic extract (ZAM) 100 mg/body weight (BW) ZAM (ZAM100), cancer with a dose of ZAM 200 mg/BW ZAM (ZAM200), and cancer with a dose of ZAM 400 mg/BW ZAM (ZAM400). Treatment lasted for 1 month. Blood samples were prepared for ELISA analysis, and cervical tissue was stained for immunohistochemistry using antibodies against IL-10, IL-1β, VEGFR1, and TGFβ1. Administration of ZAM had no significant effect on rat body weight and cervical organs (p > 0.05). However, it impacted haematological parameters in rats with cervical cancer (p < 0.05). Elevated malondialdehyde levels may be linked to superoxide dismutase deficiency in tumour tissue. ZAM significantly decreased the expression of IL1β, TGFβ1, and VEGFR1 (p < 0.01), while it increased the expression of IL-10. Therefore, ZAM may be a potential target for molecular cytokine therapy for cervical cancer.

Epineural Methylene Blue Injection May Aid Localization of Digital Nerves in Dupuytren's Surgery

Background

In Dupuytren's surgery, limited fasciectomy is still the gold-standard treatment. A relatively high risk of iatrogenic nerve injury has been observed especially when the spiral cords of the Dupuytren's tissue pull digital nerves away from their normal anatomical location. Intraoperative neural marking could facilitate locating the potentially displaced nerves. Hence, surgery could be undertaken more quickly with a lower risk of iatrogenic nerve injury.

Objectives

We hypothesize that digital nerves may be stained with methylene blue (MB) in vivo providing a visual aid to distinguish them from Dupuytren's tissue. We aim to (a) test an in vivo nerve staining technique using MB in a rat sciatic nerve model and to (b) assess the safety of epineural MB injection.

Methods

Three experiments were performed: first, the effects of (a) sham surgery, (b) epineural needle insertion, and (c) 40 μL epineural saline injection were tested in the rat sciatic nerve. Second, we determined the (a) histoanatomical localization of the epineurally injected 40 µL 1 m/m% MB stock solution and (b) we tested which saline dilution (i.e., 1:40, 1:80, and 1:160) of the stock solution does provide optimal blue color upon 40 µL epineural injection. Third, the functional and morphological effect of 40 µL 1:80 diluted MB injection was compared with that of saline, injected into the contralateral sciatic nerve. The functional effects were tested by assessing the pain threshold by using a dynamic plantar esthesiometer (DPA) and by examination of the animal's gate and paw posture. Sciatic nerves were subjected to histological examination and morphometry to test structural damage.

Results

Neither epineural needle insertion nor saline injection caused any functional or morphological changes. Histological examination revealed that the MB stained the epineural compartment. Epineural injection of 40 μL 1:80 diluted MB into the sciatic nerve stained an 18.18-mm segment of the nerve distal to the puncture point. DPA revealed unchanged pain threshold values on the plantar surface of the limbs. Normal gait and foot posture suggested normal motor functions in all groups. No histological changes were seen in the stained nerves, and the nerve fiber density remained unchanged.

Conclusion

We demonstrated that in vivo nerve staining with MB is a suitable method to mark nerves without causing detectable negative effect to the stained nerve. Human trials are required to prove the efficacy of the technique in Dupuytren's disease.

Hsp70 in cancer: A double agent in the battle between survival and death

The heat shock protein (Hsps) superfamily, also known as molecular chaperones, are highly conserved and present in all living organisms and play vital roles in protein fate. The HspA1A (Hsp70-1), called Hsp70 in this review, is expressed at low or undetectable levels in most unstressed normal cells, but numerous studies have shown that diverse types of tumor cells express Hsp70 at the plasma membrane that leads to resistance to programmed cell death and tumor progression. Hsp70 is released into the extracellular milieu in three forms including free soluble, complexed with cancer antigenic peptides, and exosome forms. Therefore, it seems to be a promising therapeutic target in human malignancies. However, a great number of studies have indicated that both intracellular and extracellular Hsp70 have a dual function. A line of evidence presented that intracellular Hsp70 has a cytoprotective function via suppression of apoptosis and lysosomal cell death (LCD) as well as that extracellular Hsp70 can promote tumorigenesis and angiogenesis. Other evidence showed intracellular Hsp70 can promote apoptosis and membrane-associated/extracellular Hsp70 can elicit antitumor innate and adaptive immune responses. Given the contradictory functions, as a "double agent," could Hsp70 be a promising tool in the future of targeted cancer therapies? To answer this question, in this review, we will discuss the functions of Hsp70 in cancers besides inhibition and stimulation strategies for targeting Hsp70 along with their challenges.

Internalization of the Aspergillus nidulans AstA Transporter into Mitochondria Depends on Growth Conditions, and Affects ATP Levels and Sulfite Oxidase Activity

The astA gene encoding an alternative sulfate transporter was originally cloned from the genome of the Japanese Aspergillus nidulans isolate as a suppressor of sulfate permease-deficient strains. Expression of the astA gene is under the control of the sulfur metabolite repression system. The encoded protein transports sulfate across the cell membrane. In this study we show that AstA, having orthologs in numerous pathogenic or endophytic fungi, has a second function and, depending on growth conditions, can be translocated into mitochondria. This effect is especially pronounced when an astA-overexpressing strain grows on solid medium at 37 °C. AstA is also recruited to the mitochondria in the presence of mitochondria-affecting compounds such as menadione or antimycin A, which are also detrimental to the growth of the astA-overexpressing strain. Disruption of the Hsp70-Porin1 mitochondrial import system either by methylene blue, an Hsp70 inhibitor, or by deletion of the porin1-encoding gene abolishes AstA translocation into the mitochondria. Furthermore, we observed altered ATP levels and sulfite oxidase activity in the astA-overexpressing strain in a manner dependent on sulfur sources. The presented data indicate that AstA is also involved in the mitochondrial sulfur metabolism in some fungi, and thereby indirectly manages redox potential and energy state.

Comparative Study Regarding the Properties of Methylene Blue and Proflavine and Their Optimal Concentrations for In Vitro and In Vivo Applications

Methylene blue and proflavine are fluorescent dyes used to stain nucleic acid from the molecular level to the tissue level. Already clinically used for sentinel node mapping, detection of neuroendocrine tumors, methemoglobinemia, septic shock, ifosfamide-induced encephalopathy, and photodynamic inactivation of RNA viruses, the antimicrobial, anti-inflammatory, and antioxidant effect of methylene blue has been demonstrated in different in vitro and in vivo studies. Proflavine was used as a disinfectant and bacteriostatic agent against many gram-positive bacteria, as well as a urinary antiseptic involved in highlighting cell nuclei. At the tissue level, the anti-inflammatory effects of methylene blue protect against pulmonary, renal, cardiac, pancreatic, ischemic-reperfusion lesions, and fevers. First used for their antiseptic and antiviral activity, respectively, methylene blue and proflavine turned out to be excellent dyes for diagnostic and treatment purposes. In vitro and in vivo studies demonstrated that both dyes are efficient as perfusion and tissue tracers and permitted to evaluate the minimal efficient concentration in different species, as well as their pharmacokinetics and toxicity. This review aims to identify the optimal concentrations of methylene blue and proflavine that can be used for in vivo experiments to highlight the vascularization of the skin in the case of a perforasome (both as a tissue tracer and in vascular mapping), as well as their effects on tissues. This review is intended to be a comparative and critical presentation of the possible applications of methylene blue (MB) and proflavine (PRO) in the surgical field, and the relevant biomedical findings from specialized literature to date are discussed as well.

Antitumor Features of Vegetal Protein-Based Nanotherapeutics

The introduction of nanotechnology into pharmaceutical application revolutionized the administration of antitumor drugs through the modulation of their accumulation in specific organs/body compartments, a decrease in their side-effects and their controlled release from innovative systems. The use of plant-derived proteins as innovative, safe and renewable raw materials to be used for the development of polymeric nanoparticles unlocked a new scenario in the drug delivery field. In particular, the reduced size of the colloidal systems combined with the peculiar properties of non-immunogenic polymers favored the characterization and evaluation of the pharmacological activity of the novel nanoformulations. The aim of this review is to describe the physico-chemical properties of nanoparticles composed of vegetal proteins used to retain and deliver anticancer drugs, together with the most important preparation methods and the pharmacological features of these potential nanomedicines.

Hsp70 inhibitors: Implications for the treatment of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies in the world. Despite intensive advances in diagnosis and treatment of CRC, it is yet one of the leading cause of cancer related morbidity and mortality. Therefore, there is an urgent medical need for alternative therapeutic approaches to treat CRC. The 70 kDa heat shock proteins (Hsp70s) are a family of evolutionary conserved heat shock proteins, which play an important role in cell homeostasis and survival. They overexpress in various types of malignancy including CRC and are typically accompanied with poor prognosis. Hence, inhibition of Hsp70 may be considered as a striking chemotherapeutic avenue. This review summarizes the current knowledge on the progress made so far to discover compounds, which target the Hsp70 family, with particular emphasis on their efficacy in treatment of CRC. We also briefly explain the induction of Hsp70 as a strategy to prevent CRC.