Efficacy of multiple low-dose photodynamic TMPYP4 therapy on cervical cancer tumour growth in nude mice

Systemic Effects of Photoactivated 5,10,15,20-tetrakis(N-methylpyridinium-3-yl) Porphyrin on Healthy Drosophila melanogaster

Porphyrins are frequently employed in photodynamic therapy (PDT), a non-invasive technique primarily utilized to treat subcutaneous cancers, as photosensitizing agents (PAs). The development of a new PA with improved tissue selectivity and efficacy is crucial for expanding the application of PDT for the management of diverse cancers. We investigated the systemic effects of 5,10,15,20-tetrakis(N-methylpyridinium-3-yl)-porphyrin (TMPyP3) using Drosophila melanogaster adult males. We established the oral administration schedule and demonstrated that TMPyP3 was absorbed and stored higher in neuronal than in non-neuronal extracts. Twenty-four hours after oral TMPyP3 photoactivation, the quantity of hydrogen peroxide (H2O2) increased, but exclusively in the head extracts. Regardless of photoactivation, TMPyP3 resulted in a reduced concentration of H2O2 after 7 days, and this was linked with a decreased capacity to climb, as indicated by negative geotaxis. The findings imply that systemic TMPyP3 therapy may disrupt redox regulation, impairing cellular signaling and behavioral outcomes in the process. To determine the disruptive effect of porphyrins on redox homeostasis, its duration, and the mechanistic variations in retention across various tissues, more research is required.

Spatial modeling connecting childhood atopic dermatitis prevalence with household exposure to pollutants

BACKGROUND

Atopic dermatitis (AD) is a chronic, inflammatory disease characterized by dry, pruritic skin. In the U.S., the prevalence of AD has increased over three-fold since the 1970s. We previously reported a geographic association between isocyanate-containing air pollution and AD as well as mechanistic data demonstrating that isocyanates induce skin dysbiosis and activate the host itch receptor TRPA1. However, non-spatial models are susceptible to spatial confounding and may overlook other meaningful associations.

METHODS

We added spatial analysis to our prior model, contrasting pollution data with clinical visits. In addition, we conducted a retrospective case-control survey of childhood exposure to BTEX-related products. Finally, we assessed implicated compounds, in pure form and as part of synthetic fabric, for their effect on the growth and metabolism of skin commensal bacteria.

RESULTS

Spatial analysis implicate benzene, toluene, ethylbenzene, and, most significantly, xylene (BTEX) compounds. Survey odds ratios for AD were significant for xylene-derived polyester bed sheets (OR = 9.5; CI 2.2-40.1) and diisocyanate-containing wallpaper adhesive (OR = 6.5; CI 1.5-27.8). Staphylococcus aureus lives longer on synthetic textiles compared to natural textiles. Meanwhile, synthetic fabric exposure shifts the lipid metabolism of health-associated commensals (Roseomonas mucosa and S. epidermidis) away from therapeutic pathways.

CONCLUSIONS

We propose that BTEX chemicals in their raw forms and in synthetic products represent a unifying hypothesis for environmentally induced AD flares through their ability to create dysbiosis in the skin microbiota and directly activate TRPA1. Unequal distribution of these pollutants may also influence racial disparities in AD rates.

Diisocyanates influence models of atopic dermatitis through direct activation of TRPA1

We recently used EPA databases to identify that isocyanates, most notably toluene diisocyanate (TDI), were the pollutant class with the strongest spatiotemporal and epidemiologic association with atopic dermatitis (AD). Our findings demonstrated that isocyanates like TDI disrupted lipid homeostasis and modeled benefit in commensal bacteria like Roseomonas mucosa through disrupting nitrogen fixation. However, TDI has also been established to activate transient receptor potential ankyrin 1 (TRPA1) in mice and thus could directly contribute to AD through induction of itch, rash, and psychological stress. Using cell culture and mouse models, we now demonstrate that TDI induced skin inflammation in mice as well as calcium influx in human neurons; each of these findings were dependent on TRPA1. Furthermore, TRPA1 blockade synergized with R. mucosa treatment in mice to improve TDI-independent models of AD. Finally, we show that the cellular effects of TRPA1 are related to shifting the balance of the tyrosine metabolites epinephrine and dopamine. This work provides added insight into the potential role, and therapeutic potential, or TRPA1 in the pathogenesis of AD.

Derivatives of Natural Chlorophylls as Agents for Antimicrobial Photodynamic Therapy

The rapid growth of drug-resistant bacteria all over the world has given rise to a major research challenge, namely a search for alternative treatments to which bacteria will be unable to develop resistance. Photodynamic therapy is an approach of this kind. It involves the use of photosensitizers in combination with visible light at a certain wavelength to excite the former and generate reactive oxygen species. Various synthetic heterocyclic compounds are used as photosensitizers. Of these, derivatives of natural chlorophylls have a special place due to their properties. This review deals with the use of such compounds in antimicrobial PDT.

Antiviral Activity of the G-Quadruplex Ligand TMPyP4 against Herpes Simplex Virus-1

The herpes simplex virus 1 (HSV-1) genome is extremely rich in guanine tracts that fold into G-quadruplexes (G4s), nucleic acid secondary structures implicated in key biological functions. Viral G4s were visualized in HSV-1 infected cells, with massive virus cycle-dependent G4-formation peaking during viral DNA replication. Small molecules that specifically interact with G4s have been shown to inhibit HSV-1 DNA replication. We here investigated the antiviral activity of TMPyP4, a porphyrin known to interact with G4s. The analogue TMPyP2, with lower G4 affinity, was used as control. We showed by biophysical analysis that TMPyP4 interacts with HSV-1 G4s, and inhibits polymerase progression in vitro; in infected cells, it displayed good antiviral activity which, however, was independent of inhibition of virus DNA replication or entry. At low TMPyP4 concentration, the virus released by the cells was almost null, while inside the cell virus amounts were at control levels. TEM analysis showed that virus particles were trapped inside cytoplasmatic vesicles, which could not be ascribed to autophagy, as proven by RT-qPCR, western blot, and immunofluorescence analysis. Our data indicate a unique mechanism of action of TMPyP4 against HSV-1, and suggest the unprecedented involvement of currently unknown G4s in viral or antiviral cellular defense pathways.

Manipulating Adult Neural Stem and Progenitor Cells with G-Quadruplex Ligands

G-quadruplexes are pervasive nucleic acid secondary structures in mammalian genomes and transcriptomes that regulate gene expression and genome duplication. Small molecule ligands that modify the stability of G-quadruplexes are widely studied in cancer, but whether G-quadruplex ligands can also be used to manipulate cell function under normal development and homeostatic conditions is largely unexplored. Here we show that two related G-quadruplex ligands (pyridostatin and carboxypyridostatin) can reduce proliferation of adult neural stem cell and progenitor cells derived from the adult mouse subventricular zone both in vitro and in vivo. Studies with neurosphere cultures show that pyridostatin reduces proliferation by a mechanism associated with DNA damage and cell death. By contrast, selectively targeting RNA G-quadruplex stability with carboxypyridostatin diminishes proliferation through a mechanism that promotes cell cycle exit and the production of oligodendrocyte progenitors. The ability to generate oligodendrocyte progenitors by targeting RNA G-quadruplex stability, however, is dependent on the cellular environment. Together, these findings show that ligands that can selectively stabilize RNA G-quadruplexes are an important, new class of molecular tool for neural stem and progenitor cell engineering, whereas ligands that target DNA G-quadruplexes have limited utility due to their toxicity.

Pegylated carbon nitride nanosheets for enhanced reactive oxygen species generation and photodynamic therapy under hypoxic conditions

The application of photodynamic therapy (PDT) is of ever-increasing importance in the treatment of malignant tumors; however, there are several major constraints that make it impossible to achieve optimal therapeutic effects. Our objective is to develop a novel photosensitizing drug for skin cancer. In the experiment, we fabricated four-arm-poly ethylene glycol modified amino-rich graphite phase carbon nitride nanosheets (AGCN-PEG), which have good stability in physiological solution and show selective accumulation in tumor cells. Under hypoxic conditions, the AGCN-PEG induced PDT can effectively inhibit growth on A431 human epidermoid carcinoma cells in vivo and in vitro. What's more, after being combined with TMPyP4, the therapeutic effect of AGCN-PEG was greatly improved.

Regioselective reduction of 5-aryl-10,15,20-tris(pyridyl) porphyrin to 5-aryl-10,15,20-tris(pyridyl)dihydroporphyrin (chlorin)

Dihydroporphyrins or chlorins differ from porphyrins only by saturation of a peripheral double bond of the macrocycle. However, this small structural difference leads to a significant increase of the absorption band at approximately 650 nm, which makes them very interesting candidates for photodynamic therapy applications. The reduction of porphyrins bearing two, three or four pyridyl substituents with tin(II) chloride has been developed for the synthesis of dihydroporphyrins in yields of 15–73%. The reduction of 5-(aryl)-10,15,20-tris(2 or 4-pyridyl)porphyrin with tin(II) chloride dihydrate demonstrated good regioselectivity. Porphyrins with one meso-aryl bearing one electron-donating group (EDG) gave 5-aryl-10,15,20-tris(2- or 4-pyridyl)-17,18-dihydroporphyrins in 17–72% yield. Porphyrins with one meso-aryl bearing one or more electron-withdrawing groups (EWG) gave 5-aryl-10,15,20-tris(4-pyridyl)-17,18-dihydroporphyrins or 5-aryl-10,15,20-tris(4-pyridyl)-7,8-dihydroporphyrins in 15–21% yield and isobacteriochlorin. We have also proven the possibility of functionalizing these compounds to design new regioisomerically pure photosensitizers.

TMPYP4 exerted antitumor effects in human cervical cancer cells through activation of p38 mitogen-activated protein kinase

Background

The aim of the present study was to investigate the potential effects of the 5,10,15,20-tetrakis (1-methylpyridinium-4-yl) porphyrin (TMPyP4) on the proliferation and apoptosis of human cervical cancer cells and the underlying mechanisms by which TMPyP4 exerted its actions.

Results

After human cervical cancer cells were treated with different doses of TMPyP4, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method, the apoptosis was observed by flow cytometry (FCM), and the expression of p38 mitogen-activated protein kinase (MAPK), phosphated p38 MAPK (p-p38 MAPK), capase-3, MAPKAPK2 (MK-2) and poly ADP-ribose polymerase (PARP) was measured by Western blot analysis. The analysis revealed that TMPyP4 potently suppressed cell viability and induced the apoptosis of human cervical cancer cells in a dose-dependent manner. In addition, the up-regulation of p-p38 MAPK expression levels was detected in TMPyP4-treated human cervical cancer cells. However, followed by the block of p38 MAPK signaling pathway using the inhibitor SB203580, the effects of TMPyP4 on proliferation and apoptosis of human cervical cancer cells were significantly changed.

Conclusions

It was indicated that TMPyP4-inhibited proliferation and -induced apoptosis in human cervical cancer cells was accompanied by activating the p38 MAPK signaling pathway. Taken together, our study demonstrates that TMPyP4 may represent a potential therapeutic method for the treatment of cervical carcinoma.

A Strategy Using Photodynamic Therapy and Clofibric Acid to Treat Peritoneal Dissemination of Ovarian Cancer

BACKGROUND

The current study examined the effectiveness of concurrent therapy using photodynamic therapy (PDT) and clofibric acid (CA) to treat peritoneal carcinomatosis resulting from ovarian cancer.

MATERIALS AND METHODS

Nude rats were used to create a model of peritoneal carcinomatosis resulting from ovarian cancer and the effectiveness of PDT with 5-aminolevulinic acid methyl ester hydrochloride (methyl-ALA-PDT) was determined. The survival time of rats receiving that therapy was compared to the survival time of a control group. Rats with peritoneal carcinomatosis resulting from ovarian cancer were divided into 3 groups: a group that received debulking surgery (DS) alone, a group that received DS+methyl-ALA-PDT, and a group that received DS+methyl-ALA-PDT+CA. The survival time of the 3 groups was compared. Protoporphyrin, a metabolite of methyl-ALA, produces a photochemical action when activated by light. The level of protoporphyrin (the concentration) that reached organs in the abdomen was measured with HPLC.

RESULTS

Rats receiving methyl- ALA-PDT had a significantly longer survival time compared to the controls. Rats with peritoneal carcinomatosis that received DS+methyl-ALA-PDT+CA had a significantly longer survival time compared to the rats that received DS alone. Some of the rats that received concurrent therapy survived for a prolonged period. Protoporphyrin was highly concentrated in peritoneal metastases, but only small amounts reached major organs in the abdomen. PDT was not found to result in necrosis in the intestines.

CONCLUSIONS

The results indicated that concurrent therapy consisting of PDT with methyl-ALA and CA is effective at treating peritoneal carcinomatosis resulting from ovarian cancer without damaging organs.

Health Risks and Benefits of Chickpea (Cicer arietinum) Consumption

Chickpeas (CPs) are one of the most commonly consumed legumes, especially in the Mediterranean area as well as in the Western world. Being one of the most nutritional elements of the human diet, CP toxicity and allergy have raised health concerns. CPs may contain various antinutritional compounds, including protease inhibitors, phytic acid, lectins, oligosaccharides, and some phenolic compounds that may impair the utilization of the nutrients by people. Also, high consumption rates of CPs have enhanced the allergic problems in sensitive individuals as they contain many allergens. On the other hand, beneficial health aspects of CP consumption have received attention from researchers recently. Phytic acid, lectins, sterols, saponins, dietary fibers, resistant starch, oligosaccharides, unsaturated fatty acids, amylase inhibitors, and certain bioactive compounds such as carotenoids and isoflavones have shown the capability of lowering the clinical complications associated with various human diseases. The aim of this paper is to unravel the health risks as well as health-promoting aspects of CP consumption and to try to fill the gaps that currently exist. The present review also focuses on various prevention strategies to avoid health risks of CP consumption using simple but promising ways.

New photosensitizers for photodynamic therapy

Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT relies on accumulation of the PS in diseased tissue and also on localized light delivery. Tetrapyrrole structures such as porphyrins, chlorins, bacteriochlorins and phthalocyanines with appropriate functionalization have been widely investigated in PDT, and several compounds have received clinical approval. Other molecular structures including the synthetic dyes classes as phenothiazinium, squaraine and BODIPY (boron-dipyrromethene), transition metal complexes, and natural products such as hypericin, riboflavin and curcumin have been investigated. Targeted PDT uses PSs conjugated to antibodies, peptides, proteins and other ligands with specific cellular receptors. Nanotechnology has made a significant contribution to PDT, giving rise to approaches such as nanoparticle delivery, fullerene-based PSs, titania photocatalysis, and the use of upconverting nanoparticles to increase light penetration into tissue. Future directions include photochemical internalization, genetically encoded protein PSs, theranostics, two-photon absorption PDT, and sonodynamic therapy using ultrasound.

Comparative study of two kinds of repeated photodynamic therapy strategies in breast cancer by using a sensitizer, sinoporphyrin sodium

Sinoporphyrin sodium (DVDMS) is a newly identified photosensitizer that was isolated from Photofrin. Experimental and clinical results have demonstrated that repeated application of PDT greatly improved the therapeutic efficacy. Here, we comparatively studied two kinds of photodynamic therapy (PDT) strategies by using DVDMS (2mg/kg) in murine breast cancer 4T1 xenograft model to provide evidence which strategy exerts a better antitumor effect. Regimen (1): DVDMS was injected one time into tumor-bearing mice, which were then repeatedly exposed to 50J/cm(2) light 24h, 30h and 36h later. Regimen (2): DVDMS was injected 3 times and mice exposed to 50J/cm(2) light 24h after each injection, with 5days intervals between each DVDMS injection. On day 21 after the tumor cell injection, in regimen (1) the tumor volume inhibition ratio was reached to 85.75±7.60%. While at the same day the inhibition ratio was 65.74±8.64% of regimen (2). Additionally, regimen (1) appeared to more effectively initiate tumor tissue destruction and cancer cell apoptosis, inhibit lung metastasis, suppress cancer cell proliferation and angiogenesis. Moreover, no obvious effect on body weight and other side effects were observed in the treated mice. These results suggest that regimen (1) might be a potentially efficient strategy against breast cancer.

TMPyP4, a Stabilizer of Nucleic Acid Secondary Structure, Is a Novel Acetylcholinesterase Inhibitor

The porphyrin compound, TMPyP4 (5,10,15,20-Tetrakis-(N-methyl-4-pyridyl)porphine), is widely used as a photosensitizer and a modulator of nucleic acid secondary structure stability. Our group recently showed in cultured cells and forebrain slice cultures that this compound can also down regulate expression of Tyrosine hydroxylase (Th), which encodes the rate-limiting enzyme in catecholamine biosynthesis, by stabilizing DNA secondary structures in the Th proximal promoter. The current study sought to establish whether treatment with TMPyP4 could modify mouse Th expression levels in vivo. Intraperitoneal administration of low TMPyP4 doses (10mg/kg), similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions. Administration of a high dose (40 mg/kg), similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner. In vitro analyses revealed that TMPyP4, but not putative metabolites, inhibited Acetylcholinesterase activity and pre-treatment of TMPyP4 with Hemeoxygenase-2 (HO-2) rescued Acetylcholinesterase function. Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses. Together, these studies indicate that only low doses of TMPyP4, such as those typically used for photosensitization, are well tolerated in vivo. Thus, despite its widespread use in vitro, TMPyP4 is not ideal for modifying neuronal gene expression in vivo by manipulating nucleic acid secondary structure stability, which highlights the need to identify more clinically suitable compounds that can modulate nucleic acid secondary structure and gene expression.

TMPyP4-regulated cell proliferation and apoptosis through the Wnt/β-catenin signaling pathway in SW480 cells

BACKGROUND

The aim of this study was to investigate the potential effects of the 5, 10, 15, 20-tetrakis (1-methylpyridinium-4-yl) porphyrin (TMPyP4) on the proliferation and apoptosis of SW480 cells and the underlying mechanisms by which TMPyP4 exerted its actions.

METHODS

After treated with different doses of TMPyP4, cell viability was determined by MTT method, the apoptosis was observed by flow cytometry (FCM) and the expression of Wnt, GSK-3β, β-catenin and cyclinD1 was measured by RT-PCR and Western blot analysis.

RESULTS

The analysis revealed that TMPyP4 potently suppressed cell viability and induced the apoptosis of SW480 cells in a dose-dependent manner. In addition, the downregulation of Wnt, β-catenin and cyclinD1 expression levels was detected in TMPyP4-treated SW480 cells. However, followed by the block of Wnt signaling pathway using siRNA methods, the effects of TMPyP4 on proliferation and apoptosis of SW480 cells were significantly reduced.

CONCLUSION

It indicates that the TMPyP4-inhibited proliferation and -induced apoptosis in SW480 cells was accompanied by the suppression of Wnt/β-catenin signaling pathway. Therefore, TMPyP4 may represent a potential therapeutic method for the treatment of colon carcinoma.

Hiporfin-mediated photodynamic therapy in preclinical treatment of osteosarcoma

This study was carried out to investigate the anti-tumor effect and mechanism of hiporfin-mediated photodynamic therapy (hiporfin-PDT) in osteosarcoma. We found that hiporfin accumulated mainly in the cytoplasm of osteosarcoma cells in a time and concentration-dependent manner. Hiporfin-PDT inhibited the proliferation, induced apoptosis and produced cell cycle arrest at G2M in osteosarcoma cell lines. Hiporfin-PDT increased the expression of cleaved-caspase-3, cleaved PARP-1, Bax and RIP1 while it decreased the expression of Bcl-2; in addition, low concentration of hiporfin increased LC3 conversion. Furthermore, cell death caused by hiporfin-PDT could be rescued by Nec-1 but not by Z-VAD-FMK. Production of reactive oxygen species was increased after hiporfin-PDT. In vivo studies showed a significant decrease in tumor volume and weight after hiporfin-PDT in all three tumor mouse models investigated (subcutaneous and orthotopic). Histological analysis showed widespread cell apoptosis and necrosis after treatment. Immunohistochemistry also showed upregulation of cleaved-caspase-3 and downregulation of Bcl-2 after hiporfin-PDT. These results indicate that hiporfin-PDT exhibits a killing effect in osteosarcoma both in vitro and in vivo, which is associated with apoptosis and necroptosis, while autophagy plays a protective role. All these findings shed light on a potential future clinical use for hiporfin in the treatment of osteosarcoma.