Antitumor Effects of 5-Aminolevulinic Acid on Human Malignant Glioblastoma Cells

Enhancing 5-ALA-PDT efficacy against resistant tumor cells: Strategies and advances

As a precursor of protoporphyrin IX (PpIX), an endogenous pro-apoptotic and fluorescent molecule, 5-Aminolevulinic acid (5-ALA) has gained substantial attention for its potential in fluorescence-guided surgery as well as photodynamic therapy (PDT). Moreover, 5-ALA-PDT has been suggested as a promising chemo-radio sensitization therapy for various cancers. However, insufficient 5-ALA-induced PpIX fluorescence and the induction of multiple resistance mechanisms may hinder the 5-ALA-PDT clinical outcome. Reduced efficacy and resistance to 5-ALA-PDT can result from genomic alterations, tumor heterogeneity, hypoxia, activation of pathways related to cell surveillance, production of nitric oxide, and most importantly, deregulated 5-ALA transporter proteins and heme biosynthesis enzymes. Understanding the resistance regulatory mechanisms of 5-ALA-PDT may allow the development of effective personalized cancer therapy. Here, we described the mechanisms underlying resistance to 5-ALA-PTD across various tumor types and explored potential strategies to overcome this resistance. Furthermore, we discussed future approaches that may enhance the efficacy of treatments using 5-ALA-PDT.

The protective effect of parthenolide in an in vitro model of Parkinson's disease through its regulation of nuclear factor-kappa B and oxidative stress

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms, and is due to the degeneration of dopaminergic neurons. It is multifactorial, caused by genetic and environmental factors and currently has no definitive cure. We have investigated the protective effects of parthenolide (PTN), a compound with known anti-inflammatory and antioxidant properties, in an in vitro model of PD, that is induced by 6-OHDA, and that causes neurotoxicity in SH-SY5Y human neuroblastoma cells.

METHODS AND RESULTS

SH-SY5Y cells were pretreated with PTN to assess its protective effects in 6-OHDA-induced cellular damage. Cell viability was measured using Alamar blue. Apoptosis was evaluated using an Annexin V-FITC/PI kit. Reactive oxygen species (ROS) levels were quantified, and expression levels of apoptotic markers (Bax, Bcl-2, p53) and NF-κB were analyzed via Western blotting and Quantitative real-time- (qRT-) PCR. We found that 6-OHDA reduced cell viability, that was inhibited significantly by pre-treatment with PTN (p < 0.05). Flow cytometry revealed that PTN reduced apoptosis induced by 6-OHDA. PTN also reduced the ROS levels raised by 6-OHDA (p < 0.05). Moreover, PTN decreased the expression of Bax, p53, NF-κB, and p-NF-κB that were increased by treatment with 6-OHDA.

CONCLUSION

These findings indicate the potential beneficial effects of PTN in an in vitro model of PD via mitigating oxidative stress and inflammation, suggested PTN as a promising agent to be used for PD therapy, warranting further investigation in preclinical and clinical studies.

Chitosan-modified manganese oxide-conjugated methotrexate nanoparticles delivering 5-aminolevulinic acid as a dual-modal T1-T2* MRI contrast agent in U87MG cell detection

OBJECTIVE

Glioblastoma multiforme is a highly aggressive form of brain cancer, and early diagnosis plays a pivotal role in improving patient survival rates. In this regard, molecular magnetic resonance imaging has emerged as a promising imaging modality due to its exceptional sensitivity to minute tissue changes and the ability to penetrate deep into the brain. This study aimed to assess the efficacy of a novel contrast agent in detecting gliomas during MRI scans.

MATERIALS AND METHODS

The contrast agent utilized modified chitosan coating on manganese oxide nanoparticles. The modification included adding methotrexate and 5-aminolevulinic acid (MnO2/CS@5-ALA-MTX) to target cells with overexpressed folate receptors and breaking down excess hydrogen peroxide in tumor tissue, resulting in enhanced signal intensity in T1-weighted MR images but diminished signal intensity in T2*-weighted MR images.

RESULTS

The nanosystem was characterized and evaluated in MR imaging, safety, and ability to target cells both in vivo and in vitro. MTX-free nanoparticles (MnO2/CS@5-ALA NPs) had no obvious cytotoxicity on cell lines U87MG and NIH3T3 after 24/48 h at a concentration of up to 160 µgr/mL (cell viability more than 80%). In this system, methotrexate enables tumor targeting and the MnO2/5-ALA improves T1-T2*-weighted MRI. In addition, MRI scans of mice with M109 carcinoma indicated significant tumor uptake and NP capacity to improve the positive contrast effect.

CONCLUSION

This developed MnO2/CS@5-ALA-MTX nanoparticle system may exhibit great potential in the accurate diagnosis of folate receptor over-expressing cancers such as glioblastoma.

Immunogenic cell death mediated TLR3/4-activated MSCs in U87 GBM cell line

Background and aims

Glioblastoma (GBM) is an aggressive primary brain cancer with no promising curative therapies. It has been indicated that MSCs can interact with the tumour microenvironment (TME) through the secretion of soluble mediators regulating intercellular signalling within the TME. TLRs are a multigene family of pattern recognition receptors with evolutionarily conserved regions and are widely expressed in immune and other body cells. MSCs by TLRs can recognize conserved molecular components (DAPMPs and PAPMPs) and activate signalling pathways, which regulate immune and inflammatory responses. MSCs may exert immunomodulatory functions through interaction with their expressed toll-like receptors (TLRs) and exert a protective effect against tumour antigens. As an emerging approach, we aimed to monitor the U87 cell line growth, migration and death markers following specific TLR3/4-primed-MSCs-CMs treatment.

Methods and results

We investigated the phenotypic and functional outcomes of primed-CMs and glioma cell line co-culture following short-term, low-dose TLR3/4 priming. The gene expression profile of target genes, including apoptotic markers and related genes, was analyzed by qRT-PCR. MicroRNA-Seq examined the miRNA expression patterns, and flow cytometry evaluated the cell viability and cycle stages. The results showed significant changes in apoptosis and likely necroptosis-related markers following TLR3/4-primed-MSCs-CMs exposure in the glioma cell line. Notably, we observed a considerable induction of selective pro-apoptotic markers and both the early and late stages of apoptosis in treated U87 cell lines. Additionally, the migration rate of glioma cells significantly decreased following MSCs-CM treatment.

Conclusion

Our findings confirmed that the exposure of TLR3/4-activated-MSCs-CMs with glioma tumour cells possibly changes the immunogenicity of the tumour microenvironment and induces immunogenic programmed cell death. Our results can support the idea that TLR3/4-primed-MSCs can lead to innate immune-mediated cell death and modify tumour cell biology in invasive and metastatic cancers.

Urolithin B inhibits proliferation and migration and promotes apoptosis and necrosis by inducing G2/M arrest and targeting MMP-2/-9 expression in osteosarcoma cells

Osteosarcoma (OS) is the most prevalent primary bone cancer, with a high morbidity and mortality rate. Over the past decades, therapeutic approaches have not considerably improved patients' survival rates, and further research is required to find efficient treatments for OS. Data from several studies have shown that urolithin B (UB), the intestinal metabolite of polyphenolic ellagitannins, is emerging as a new class of anticancer compounds, yet its effect on OS cancer cells remains elusive. Herein, we investigated UB's antimetastatic, antiproliferative, and apoptotic effects on the MG-63 OS cell line. Cell viability assay, annexin V/propidium iodide staining, cell cycle arrest analysis, determination of the gene expression of MMP-2, MMP-9, Bax, Bcl-2, and p53 messenger RNA (mRNA), evaluation of reactive oxygen species (ROS) generation and migration, and MMP-2 and MMP-9 protein expression assessments were performed. UB caused late apoptosis, necrosis, G2/M arrest, and ROS generation in MG-63 cells. It increased the mRNA expression of the p53 tumor suppressor and Bax proapoptotic genes. UB also inhibited the migration and metastatic behavior of MG-63 OS cells by downregulating mRNA and MMP-2 and MMP-9 protein expression. In general, although further in vivo investigations are warranted, the current results showed that UB might be utilized as a potential novel natural compound for OS therapy due to its nontoxic, antiproliferative, and antimetastatic nature.

Radiation-induced photodynamic therapy using calcium tungstate nanoparticles and 5-aminolevulinic acid prodrug

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) prodrug is a clinically tried and proven treatment modality for surface-level lesions. However, its use for deep-seated tumors has been limited due to the poor penetration depth of visible light needed to activate the photosensitizer protoporphyrin IX (PPIX), which is produced from ALA metabolism. Herein, we report the usage of poly(ethylene glycol-b-lactic acid) (PEG-PLA)-encapsulated calcium tungstate (CaWO4, CWO for short) nanoparticles (PEG-PLA/CWO NPs) as energy transducers for X-ray-activated PDT using ALA. Owing to the spectral overlap between radioluminescence afforded by the CWO core and the absorbance of PPIX, these NPs can serve as an in situ visible light activation source during radiotherapy (RT), thereby mitigating the limitation of penetration depth. We demonstrate that this effect is observed across different cell lines with varying radio-sensitivity. Importantly, both PPIX and PEG-PLA/CWO NPs exhibit no significant toxicities at therapeutic doses in the absence of radiation. To assess the efficacy of this approach, we conducted a study using a syngeneic mouse model subcutaneously implanted with inherently radio-resistant 4T1 tumors. The results show a significantly improved prognosis compared to conventional RT, even with as few as 2 fractions of 4 Gy X-rays. Taken together, these results suggest that PEG-PLA/CWO NPs are promising agents for application of ALA-PDT in deep-seated tumors, thereby significantly expanding the utility of the already established treatment strategy.

The in vitro anti-cancer synergy of neurokinin-1 receptor antagonist, aprepitant, and 5-aminolevulinic acid in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant type of cerebral neoplasm in adults with a poor prognosis. Currently, combination therapy with different anti-cancer agents is at the forefront of GBM research. Hence, this study aims to evaluate the potential anti-cancer synergy of a clinically approved neurokinin-1 receptor antagonist, aprepitant, and 5-aminolevulinic acid (5-ALA), a prodrug that elicits fluorescent porphyrins in gliomas on U-87 human GBM cells. We found that aprepitant and 5-ALA effectively inhibited GBM cell viability. The combinatorial treatment of these drugs exerted potent synergistic growth inhibitory effects on GBM cells. Moreover, aprepitant and 5-ALA induced apoptosis and altered the levels of apoptotic genes (up-regulation of Bax and P53 along with downregulation of Bcl-2). Furthermore, aprepitant and 5-ALA increased the accumulation of protoporphyrin IX, a highly pro-apoptotic and fluorescent photosensitizer. Aprepitant and 5-ALA significantly inhibited GBM cell migration and reduced matrix metalloproteinases (MMP-2 and MMP-9) activities. Importantly, all these effects were more prominent following aprepitant-5-ALA combination treatment than either drug alone. Collectively, the combination of aprepitant and 5-ALA leads to considerable synergistic anti-proliferative, pro-apoptotic, and anti-migratory effects on GBM cells and provides a firm basis for further evaluation of this combination as a novel therapeutic approach for GBM.

Urolithin B loaded in cerium oxide nanoparticles enhances the anti-glioblastoma effects of free urolithin B in vitro

Glioblastoma multiforme (GBM) is the most aggressive kind of malignant primary brain tumor in humans. Given the limitation of Conventional therapeutic strategy, the development of nanotechnology and natural product therapy seems to be an effective method enhancing the prognosis of GBM patients. In this research, cell viability, mRNA expressions of various apoptosis-related genes apoptosis, and generation of reactive oxygen species (ROS) in human U-87 malignant GBM cell line (U87) treated with Urolithin B (UB) and CeO₂-UB. Unlike CeO₂-NPs, both UB and CeO₂-UB caused a dose-dependent decrease in the viability of U87 cells. The half-maximal inhibitory concentration values of UB and CeO₂-UB were 315 and 250 μM after 24 h, respectively. Moreover, CeO₂-UB exerted significantly higher effects on U87 viability, P53 expression, and ROS generation. Furthermore, UB and CeO2-UB increased the accumulation of U87 cells in the SUB-G1 population, decreased the expression of cyclin D1, and increased the Bax/Bcl2 ratio expression. Collectively, these data indicate that CeO₂-UB exhibited more substantial anti-GBM effects than UB. Although further in vivo investigations are needed, these results proposed that CeO₂-NPs could be utilized as a potential novel anti-GBM agent after further studies.

Inhibition of glioblastoma proliferation, invasion, and migration by Urolithin B through inducing G0/G1 arrest and targeting MMP-2/-9 expression and activity

One kind of brain cancer with a dismal prognosis is called glioblastoma multiforme (GBM) due to its high growth rate and widespread tumor cell invasion into various areas of the brain. To improve therapeutic approaches, the objective of this research investigates the cytotoxic, anti-metastatic, and apoptotic effect of urolithin-B (UB) as a bioactive metabolite of ellagitannins (ETs) on GBM U87 cells. The malignant GBM cell line (U87) was examined for apoptosis rate, cell cycle analysis, cell viability, mRNA expressions of several apoptotic and metastasis-associated genes, production of reactive oxygen species (ROS), MMP-2, and MMP-9 activity and protein expression, and migration ability. The findings revealed that UB decreased U87 GBM viability in a dose-dependent manner and NIH/3T3 normal cells with the IC₅₀ value of 30 and 55 μM after 24 h, respectively. UB also induces necrosis and G0/G1 cell cycle arrest in U87 cells. UB also increases ROS production and caused down-regulation of Bcl2 and up-regulation of Bax apoptotic genes. Additionally, treatment of UB reduced the migration of U87 cells. The protein levels, mRNA expression, and the MMP-2 and MMP-9 enzyme activities also decreased concentration-dependently. So, due to the non-toxic nature of UB and its ability to induce apoptosis and reduce the U87 GBM cell invasion and migration, after more research, it can be regarded as a promising new anti-GBM compound.

Mechanisms of Cell Cycle Arrest and Apoptosis in Glioblastoma

Cells of glioblastoma, the most frequent primary malignant brain tumor, are characterized by their rapid growth and infiltration of adjacent healthy brain parenchyma, which reflects their aggressive biological behavior. In order to maintain their excessive proliferation and invasion, glioblastomas exploit the innate biological capacities of the patients suffering from this tumor. The pathways involved in cell cycle regulation and apoptosis are the mechanisms most commonly affected. The following work reviews the regulatory pathways of cell growth in general as well as the dysregulated cell cycle and apoptosis relevant mechanisms observed in glioblastomas. We then describe the molecular targeting of the current established adjuvant therapy and present ongoing trials or completed studies on specific promising therapeutic agents that induce cell cycle arrest and apoptosis of glioblastoma cells.

Inhibition of autophagy with Chloroquine enhanced apoptosis induced by 5-aminolevulinic acid-photodynamic therapy in secondary hyperparathyroidism primary cells and organoids

Secondary hyperparathyroidism (SHPT), the most common complication in the later stage of chronic kidney disease (CKD), seriously affects quality of life and the survival time of patients. At present, the conventional drugs and surgical methods still cannot fully meet the needs of clinical treatment. It is quite significant to develop effective and minimally invasive treatment methods. 5-Aminolevulinic acid-mediated photodynamic therapy (5-ALA-PDT), an alternative treatment relying on light irradiation, photosensitizer, and oxygen to produce a series of cytotoxic effects on tissue, is a promising technique for treating SHPT. We have successfully cultivated SHPT primary cells and organoids, and further proved that the amount of 5-ALA transformed into protoporphyrin IX in a time- and concentration-dependent manner. Also, 5-ALA-PDT exerted a cytotoxic effect on both primary cells and organoids by the cell counting kit (CCK-8) assay. Mechanically, 5-ALA-PDT increased the number of autophagosomes, and autophagy- and apoptosis-related proteins were upregulated markedly by western-blotting. The autophagy inhibitor Chloroquine (CQ) significantly increased the proportion of apoptotic cells, while the autophagy inducer rapamycin decreased the inhibitory ability of 5-ALA-PDT in SHPT primary cells. In brief, 5-ALA-PDT exhibits a phototoxic effect on SHPT primary cells and organoids. Autophagy and apoptosis are involved in the mechanism, and autophagy plays a role in promoting survival and inhibiting apoptosis. Therefore, the use of autophagy inhibitors can increase the sensitivity of SHPT cells and organoids treated with 5-ALA-PDT.