A systematic review and meta-analysis of fluorescent-guided resection and therapy-based photodynamics on the survival of patients with glioma

Sonodynamic therapy with a single neoadjuvant, diffuse delivery of low-intensity ultrasound with 5-ALA in treatment naïve glioblastoma results in tumor-specific cytotoxic edema and increased apoptosis

PURPOSE

Sonodynamic therapy, which combines a tumor cell-selective sonosensitizer with ultrasound, is gaining attention as a promising new treatment approach for glioblastoma. The objective of this case study is to report on the first applications of 5-aminolevulinic acid (5-ALA) in combination with low-intensity, non-targeted ultrasound as neo-adjuvant treatment in therapy naïve glioblastoma.

METHODS

Three patients with therapy naïve newly diagnosed glioblastoma were treated once before cytoreductive surgery with 5-ALA in combination with hemispheric, low-intensity, non-targeted ultrasound, assuming cell death to be triggered by non-ablative activation of 5-ALA-induced, tumor selective porphyrins.

RESULTS

No adverse effects were noted. Post-procedural MRI indicated a decrease in apparent diffusion coefficient values in tumors, suggesting cytotoxic effects. Relative cerebral blood volumes and leakage were increased for two patients with available perfusion imaging. Tissue obtained during surgery suggested increased cleaved-caspase III expression, a marker of apoptosis.

CONCLUSION

We saw an immediate marked imaging response indicating cytotoxic edema and indications of a histopathology response from just a single treatment. Correlation to clinical outcomes and extension of overall survival remains to be seen. A Phase 1 safety study has been submitted for regulatory approval.

Erlotinib Improves the Response of Glioblastoma Cells Resistant to Photodynamic Therapy

Background: Glioblastoma (GBM) is the most common and deadly type of brain cancer in adults. Dysregulation of receptor tyrosine kinase pathways, such as the epidermal growth factor receptor (EGFR), contributes to therapeutic resistance. Drugs that inhibit tyrosine kinase activity and monoclonal antibodies against EGFR are strategies used in clinical trials. Photodynamic therapy (PDT) is a tumor treatment that involves the administration of a photosensitizing drug, followed by its activation with visible light, which causes cell death due to oxidative stress. Although PDT helps prolong median survival in patients with GBM, complete remission has not been achieved. Populations of GBM cells have been obtained from the T98G line resistant to PDT with methyl-5-aminolevulinic acid (Me-ALA) for characterization, comparing them with the original parental population. Objective: The objective of this work was to evaluate the general response of T98G GBM cells resistant to PDT when EGFR activity is inhibited with the drug erlotinib. Methods and Results: It has been observed that the administration of the EGFR inhibitor drug in combination with PDT reduced viability (MTT) in resistant populations compared to PDT alone. Furthermore, the PpIX content (flow cytometry) was increased in the resistant population when cells were incubated with Me-ALA and erlotinib. Erlotinib prevented cell proliferation of parental and resistant spheroids. Wound closure was reduced in both parental and PDT-resistant populations. Conclusions: Our results indicate that EGFR activation would be relevant in the resistance of GBM cells to PDT.

Photodynamic therapy with curcumin and near-infrared radiation as an antitumor strategy to glioblastoma cells

Glioblastoma is a malignant neoplasm that develops in the central nervous system and is characterized by high rates of cell proliferation and invasion, presenting resistance to treatments and a poor prognosis. Photodynamic therapy (PDT) is a therapeutic modality that can be applied in oncological cases and stands out for being less invasive. Photosensitizers (PS) of natural origin gained prominence in PDT. Curcumin (CUR) is a natural compound that has been used in PDT, considered a promising PS. In this work, we evaluated the effects of PDT-mediated CUR and near-infrared radiation (NIR) in glioblastoma cells. Through trypan blue exclusion analysis, we chose the concentration of 5 μM of CUR and the dose of 2 J/cm2 of NIR that showed better responses in reducing the viable cell number in the C6 cell line and did not show cytotoxic/cytostatic effects in the HaCat cell line. Our results show that there is a positive interaction between CUR and NIR as a PDT model since there was an increase in ROS levels, a decrease in cell proliferation, increase in cytotoxicity with cell death by autophagy and necrosis, in addition to the presence of oxidative damage to proteins. These results suggest that the use of CUR and NIR is a promising strategy for the antitumor application of PDT.

The Implication of Photodynamic Therapy Applied to the Level of Tumor Resection on Postoperative Cerebral Edema and Intracranial Pressure Changes in Gliomas

AIM

The aim of our study was to explore the factors influencing cerebral edema and intracranial pressure in glioblastoma multiforme (GBM) patients who undergo photodynamic therapy (PDT) after resection.

APPROACH

This was a retrospective controlled study of GBM patients treated with PDT-assisted resections of varying scope from May 2021 to August 2023. The baseline clinical data, cerebral edema volumes, intracranial pressure values, and imaging data of the GBM patients were collected for statistical analysis.

RESULTS

A total of 56 GBM patients were included. Thirty of the patients underwent gross total resection (GTR), and the other 26 patients underwent subtotal resection (STR). We found that the cerebral edema volume and the mean intracranial pressure in patients who underwent GTR were lower than those in patients who underwent STR. Moreover, univariate analysis showed that the scope of tumor resection was an independent factor affecting cerebral edema and intracranial pressure after PDT.

CONCLUSIONS

Compared with STR, PDT combined with GTR significantly reduced postoperative brain edema volume and intracranial pressure in GBM patients.

Hematoporphyrin derivative-mediated photodynamic techniques for the diagnosis and treatment of chordoma

BACKGROUND

Chordoma is a rare congenital low-grade malignant tumor characterized by infiltrative growth. It often tends to compress important intracranial nerves and blood vessels, making its surgical treatment extremely difficult. Besides, the efficacy of radiotherapy and chemotherapy is limited. The photosensitizer hematoporphyrin derivative (HPD) can emit red fluorescence under 405 nm excitation and produce reactive oxygen species for tumor therapy under 630 nm excitation. Herein, we investigated the effects of the photosensitizer hematoporphyrin derivative (HPD) on different cell lines of chordoma and xenograft tumors under 405 nm and 630 nm excitation.

METHODS

The photosensitizer hematoporphyrin derivative (HPD) and Two different chordoma cell lines (U-CH1, JHC7) were used for the test. The in vitro experiments were as follows: (1) the fluorescence intensity emitted by chordoma cells excited by different 405 nm light intensities was observed under a confocal microscope; (2) the Cell Counting Kit-8 (CCK-8) assay was performed to detect the effects of different photosensitizer concentrations and 630 nm light energy densities on the activity of chordoma cells. In the in vivo experiments, (3) Fluorescence visualization of chordoma xenograft tumors injected with photosensitizer via tail vein under 405 nm excitation; (4) Impact of 630 nm excitation of photosensitizer on the growth of chordoma xenograft tumors.

RESULTS

(1) The photosensitizers in chordoma cells and chordoma xenografts of nude mice were excited by 405 nm to emit red fluorescence; (2) 630 nm excitation photosensitizer reduces chordoma cell activity and inhibits chordoma xenograft tumor growth in chordoma nude mice.

CONCLUSION

Photodynamic techniques mediated by the photosensitizer hematoporphyrin derivatives can be used for the diagnosis and treatment of chordoma.

Current Photodynamic Therapy for Glioma Treatment: An Update

Research on the development of photodynamic therapy for the treatment of brain tumors has shown promise in the treatment of this highly aggressive form of brain cancer. Analysis of both in vivo studies and clinical studies shows that photodynamic therapy can provide significant benefits, such as an improved median rate of survival. The use of photodynamic therapy is characterized by relatively few side effects, which is a significant advantage compared to conventional treatment methods such as often-used brain tumor surgery, advanced radiotherapy, and classic chemotherapy. Continued research in this area could bring significant advances, influencing future standards of treatment for this difficult and deadly disease.

FBLIM1 mRNA is a novel prognostic biomarker and is associated with immune infiltrates in glioma

Glioma is the most common primary brain tumor. Filamin-binding LIM protein 1 (FBLIM1) has been identified in multiple cancers and is suspected of playing a part in the development of tumors. However, the potential function of FBLIM1 mRNA in glioma has not been investigated. In this study, the clinical information and transcriptome data of glioma patients were, respectively, retrieved from the TCGA and CGGA databases. The expression level of FBLIM1 mRNA was shown to be aberrant in a wide variety of malignancies. Significantly, when glioma samples were compared to normal brain samples, FBLIM1 expression was shown to be significantly elevated in the former. A poor prognosis was related to high FBLIM1 expression, which was linked to more advanced clinical stages. Notably, multivariate analyses demonstrated that FBLIM1 expression was an independent predictor for the overall survival of glioma patients. Immune infiltration analysis disclosed that FBLIM1 expression had relevance with many immune cells. The results of RT-PCR suggested that FBLIM1 expression was markedly elevated in glioma specimens. Functional experiments unveiled that the knockdown of FBLIM1 mRNA suppressed glioma cell proliferation. In general, we initially discovered that FBLIM1 mRNA might be a possible prognostic marker in glioma.

Novel Iron-Chelating Prodrug Significantly Enhanced Fluorescence-Mediated Detection of Glioma Cells Experimentally In Vitro

(1) Background: The protoporphyrin IX (PpIX)-mediated fluorescence-guided resection and interoperative photodynamic therapy (PDT) of remaining cells may be effective adjuvants to the resection of glioma. Both processes may be enhanced by increasing intracellular PpIX concentrations, which can be achieved through iron chelation. AP2-18 is a novel combinational drug, which ester-links a PpIX precursor (aminolaevulinic acid; ALA) to an iron-chelating agent (CP94). (2) Methods: Human glioma U-87 MG cells were cultured in 96-well plates for 24 h and incubated for 3 or 6 h with various test compound combinations: ALA (±) CP94, methyl aminolevulinate (MAL) (±) CP94 and AP2-18. PpIX fluorescence was measured at 0, 3 or 6 h with a Bio-tek Synergy HT plate reader, as well as immediately after irradiation with a 635 nm red light (Aktilite CL16 LED array), representing the PDT procedure. Cell viability post-irradiation was assessed using the neutral red assay. (3) Results: AP2-18 significantly increased PpIX fluorescence compared to all other test compounds. All treatment protocols effectively achieved PDT-induced cytotoxicity, with no significant difference between test compound combinations. (4) Conclusions: AP2-18 has potential to improve the efficacy of fluorescence-guided resection either with or without the subsequent intraoperative PDT of glioma. Future work should feature a more complex in vitro model of the glioma microenvironment.