Porfimer-sodium (Photofrin-II) in combination with ionizing radiation inhibits tumor-initiating cell proliferation and improves glioblastoma treatment efficacy

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.

High quantum efficiency ruthenium coordination complex photosensitizer for improved radiation-activated Photodynamic Therapy

Traditional external light-based Photodynamic Therapy (PDT)'s application is limited to the surface and minimal thickness tumors because of the inefficiency of light in penetrating deep-seated tumors. To address this, the emerging field of radiation-activated PDT (radioPDT) uses X-rays to trigger photosensitizer-containing nanoparticles (NPs). A key consideration in radioPDT is the energy transfer efficiency from X-rays to the photosensitizer for ultimately generating the phototoxic reactive oxygen species (ROS). In this study, we developed a new variant of pegylated poly-lactic-co-glycolic (PEG-PLGA) encapsulated nanoscintillators (NSCs) along with a new, highly efficient ruthenium-based photosensitizer (Ru/radioPDT). Characterization of this NP via transmission electron microscopy, dynamic light scattering, UV-Vis spectroscopy, and inductively coupled plasma mass-spectroscopy showed an NP size of 120 nm, polydispersity index (PDI) of less than 0.25, high NSCs loading efficiency over 90% and in vitro accumulation within the cytosolic structure of endoplasmic reticulum and lysosome. The therapeutic efficacy of Ru/radioPDT was determined using PC3 cell viability and clonogenic assays. Ru/radioPDT exhibited minimal cell toxicity until activated by radiation to induce significant cancer cell kill over radiation alone. Compared to protoporphyrin IX-mediated radioPDT (PPIX/radioPDT), Ru/radioPDT showed higher capacity for singlet oxygen generation, maintaining a comparable cytotoxic effect on PC3 cells.

Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective

Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

Integrated Transcriptome Analysis Reveals the Impact of Photodynamic Therapy on Cerebrovascular Endothelial Cells

Blood vessels in the brain tissue form a compact vessel structure and play an essential role in maintaining the homeostasis of the neurovascular system. The low dosage of photodynamic intervention (PDT) significantly affects the expression of cellular biomarkers. To understand the impact of photodynamic interventions on cerebrovascular endothelial cells, we evaluated the dosage-dependent impact of porfimer sodium-mediated PDT on B.END3 cells using flow cytometer, comet assay, RNA sequencing, and bioinformatics analysis. To examine whether PDT can induce disorder of intracellular organelles, we did not observe any significance damage of DNA and cellular skeleton. Moreover, expression levels of cellular transporters-related genes were significantly altered, implying the drawbacks of PDT on cerebrovascular functions. To address the potential molecular mechanisms of these phenotypes, RNA sequencing and bioinformatics analysis were employed to identify critical genes and pathways among these processes. The gene ontology (GO) analysis and protein-protein interaction (PPI) identified 15 hub genes, highly associated with cellular mitosis process (CDK1, CDC20, MCM5, MCM7, MCM4, CCNA2, AURKB, KIF2C, ESPL1, BUB1B) and DNA replication (POLE2, PLOE, CDC45, CDC6). Gene set enrichment analysis (GSEA) reveals that TNF-α/NF-κB and KRAS pathways may play a critical role in regulating expression levels of transporter-related genes. To further perform qRT-PCR assays, we find that TNF-α/NF-κB and KRAS pathways were substantially up-regulated, consistent with GSEA analysis. The current findings suggested that a low dosage of PDT intervention may be detrimental to the homeostasis of blood-brain barrier (BBB) by inducing the inflammatory response and affecting the expression of surface biomarkers.

Porfimer Sodium Versus PS785 for Photodynamic Therapy (PDT) of Lung Cancer Xenografts in Mice

BACKGROUND

Lung cancer is the greatest cause of cancer mortality in the United States, necessitating ongoing improvements in current treatment techniques. Photodynamic therapy (PDT) involves the interaction between a photosensitizer, light, and oxygen. The resulting release of reactive oxygen species causes tumor necrosis. It has been used as an endoscopic technique for the palliation of lung cancer. Porfimer sodium (Photofrin) is the only Food and Drug Administration-approved photosensitizer for PDT but has limited depth of penetration and produces prolonged skin phototoxicity. Multiple newer photosensitizers are in development, including PS785. The effectiveness of PS785 was compared with porfimer sodium in the treatment of human lung cancer xenografts in mice.

METHODS

Human non-small cell lung cancer (NSCLC) xenografts were established in severe combined immunodeficient mice and grouped into small (3-5 mm) and large tumors (6-10 mm). PS785 or porfimer sodium was administered intravenously, and PDT was executed at 24, 48, or 72 h after injection. The primary endpoint was the delay of tumor regrowth after PDT.

RESULTS

Porfimer sodium and PS785 produced statistically similar delays of tumor regrowth after PDT when small tumors were treated at 24 and 48 h. At 72 h, PS785 performed better in small tumors. However, for large tumors, PS785 produced no delay in tumor regrowth at any time point.

CONCLUSIONS

PS785 and porfimer sodium were able to effectively treat NSCLC to a depth of ≤5 mm. However, porfimer sodium was more effective in treating NSCLC tumors to a depth of 6-10 mm. Further efforts are required to produce photosensitizers that will facilitate PDT of larger tumors.

5-Aminolevulinic acid radiodynamic therapy for treatment of high-grade gliomas: A systematic review

INTRODUCTION

Radiodynamic therapy (RDT) involves administration of a radiosensitizing agent and its subsequent activation by ionizing radiation for destruction of neoplastic cells.

MATERIALS AND METHODS

A comprehensive evaluation of the literature was performed to review the history of RDT using porphyrins for solid tumors, the cellular mechanisms of action, immunomodulatory effects, and both preclinical and clinical studies for use in high-grade gliomas (HGGs). This manuscript was prepared in accordance with the PRISMA guidelines.

RESULTS

A total of 271 articles were considered for initial review. After removal of duplicates, articles not unrelated to specific topic, and exclusion of commentary articles, a total of 11 articles were subject to full analysis that included in vivo, in vitro, and human studies. Porphyrins such as 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) selectively accumulate in neoplastic cells and are currently used for fluorescent-guided surgical resection and photodynamic therapy (PDT) of HGG and other brain tumors. 5-ALA is also shown to act as a radiosensitizer by increasing oxidative stress in neoplastic cell mitochondria and enhancing the host immune response. Postoperative radiation therapy is currently the standard of care for treatment of HGG.

CONCLUSION

RDT remains a promising adjuvant therapy for HGGs and requires further investigation. Clinical trials of 5-ALA RDT for HGG are needed to evaluate the optimum timing, dosing and effectiveness.

Potentiality, Limitations, and Consequences of Different Experimental Models to Improve Photodynamic Therapy for Cancer Treatment in Relation to Antiangiogenic Mechanism

The relevance of experimentally gained information represents a long-term debating issue in the field of molecular biology research. The loss of original conditions in the in vitro environment affects various biological mechanisms and cellular interactions. Consequently, some biochemical mechanisms are lost or critically altered. Analyses in these modified conditions could, therefore, distort the relevancy of experimentally gained information. In some cases, the similarities with original conditions are so small that utilization of simpler in vitro models seems impossible, or could occur in a very limited way. To conclude, the study of more complex phenomena places higher demands on the complexity of the experimental model. The latest information highlights the fact that the tumor angiogenesis mechanism has very complex features. This complexity can be associated with a wide range of angiogenic factors expressed by a variety of malignant and non-malignant cells. Our article summarizes the results from various experimental models that were utilized to analyze a photodynamic therapy effect on tumor angiogenic mechanisms. Additionally, based on the latest information, we present the most important attributes and limitations of utilized experimental models. We also evaluate the essential problems associated with angiogenic mechanism induction after photodynamic therapy application.

Investigation of combined photodynamic and radiotherapy effects of gallium phthalocyanine chloride on MCF-7 breast cancer cells

In this study, we evaluated the effect of gallium phthalocyanine chloride (GaPcCl) as a radio- and photosensitizer on MCF-7 breast cancer cell line. We incubated cells with GaPcCl in different concentrations (from 3.125 to 100 μg/ml). Then cells in separate groups were exposed to different light doses (1.8 and 2.8 J/cm²) at wavelength of 660 nm and 2-Gy X-ray ionizing radiation, alone and in combination. Finally, cell survival and apoptosis were determined by MTT assay and flow cytometry, respectively. The results showed that the deactivated GaPcCl at concentration of 100 µg/ml reduces the cell viability up to 15%. While, photoactivated GaPcCl (100 µg/ml) at light dose of 2.8 J/cm² significantly decreases cell viability up to 55.3%. Although MTT assay demonstrated that GaPcCl is not act as a radiosensitizer, flow cytometry showed significant increase in cell apoptosis when GaPcCl was exposed to 2 Gy X-ray. Using of GaPcCl-PDT (photodynamic therapy) integration with X-ray substantially increased cell death in comparison to the absence of X-ray. Furthermore, flow cytometry displayed a significant increase in apoptosis cells (especially late apoptosis) in this combination therapy. Our result proved that GaPcCl is an effective photosensitizer in MCF-7 human breast cancer cell line. The combination of GaPcCl-PDT and radiotherapy can be an efficient treatment against cancer. This approach needs further investigations on animal models for human purposes.Graphic abstract.

Induced cancer stem cells generated by radiochemotherapy and their therapeutic implications

Local and distant recurrence of malignant tumors following radio- and/or chemotherapy correlates with poor prognosis of patients. Among the reasons for cancer recurrence, preexisting cancer stem cells (CSCs) are considered the most likely cause due to their properties of self-renewal, pluripotency, plasticity and tumorigenicity. It has been demonstrated that preexisting cancer stem cells derive from normal stem cells and differentiated somatic cells that undergo transformation and dedifferentiation respectively under certain conditions. However, recent studies have revealed that cancer stem cells can also be induced from non-stem cancer cells by radiochemotherapy, constituting the subpopulation of induced cancer stem cells (iCSCs). These findings suggest that radiochemotherapy has the side effect of directly transforming non-stem cancer cells into induced cancer stem cells, possibly contributing to tumor recurrence and metastasis. Therefore, drugs targeting cancer stem cells or preventing dedifferentiation of non-stem cancer cells can be combined with radiochemotherapy to improve its antitumor efficacy. The current review is to investigate the mechanisms by which induced cancer stem cells are generated by radiochemotherapy and hence provide new strategies for cancer treatment.

Current status and future perspectives of sonodynamic therapy in glioma treatment

Malignant glioma is one of the most challenging central nervous system diseases to treat, and has high rates of recurrence and mortality. The current therapies include surgery, radiation therapy, and chemotherapy, although these approaches often failed to control tumor progression or improve patient survival. Sonodynamic therapy is a developing cancer treatment that uses ultrasound combined with a sonosensitizer to synergistically kill tumor cells, and has provided impressive results in both in vitro and in vivo studies. The ultrasound waves can penetrate deep tissues and reversibly open the blood-brain barrier to enhance drug delivery to the brain. Thus, sonodynamic therapy has a promising potential in glioma treatment. In this review, we summarize the studies that have confirmed the pre-clinical efficacy of sonodynamic therapy for glioma treatment, and discuss the future directions for this emerging treatment.

In vitro enrichment of tumor-initiating cells from human established cell lines

This unit describes protocols for culturing and subsequently enriching cancer stem cells (CSCs), also referred to as tumor-initiating cells (TICs), from human established cell lines. TICs are thought to display the major cell population in the tumor with the proliferative capacity to seed tumors, implying that they( )are critical in initiating and driving tumorigenesis. The protocols show the methods for enriching and subsequently characterizing TIC populations from a series of human tumors including glioblastoma, breast, and pancreatic tumors. Protocols evaluating the morphology, phenotypic, and functional properties of TICs are described. Long-term cultures grown either as monolayers ("TIC-low") or as non-adherent tumor spheres ("TIC-high") are generated. As a result, cells from the TIC-high culture exhibit increased expression of stem cell surface markers, such as CD133, CD44, and CD24, high aldehyde dehydrogenase (ALDH) activity, and elevated expression levels of p21, in comparison to cells from the TIC-low culture. Studying TICs by using such protocols is cost effective and is considered as a suitable and simple way for studying them.