Radiotherapy using IMRT boosts after hyperbaric oxygen therapy with chemotherapy for glioblastoma

Melatonin for gastric cancer treatment: where do we stand?

Gastric cancer (GC) is the third leading reason of death in men and the fourth in women. Studies have documented an inhibitory function of melatonin on the proliferation, progression and invasion of GC cells. MicroRNAs (miRNAs) are small, non-coding RNAs that play an important function in regulation of biological processes and gene expression of the cells. Some studies reported that melatonin can suppress the progression of GC by regulating the exosomal miRNAs. Thus, melatonin represents a promising potential therapeutic agent for subjects with GC. Herein, we evaluate the existing data of both in vivo and in vitro studies to clarify the molecular processes involved in the therapeutic effects of melatonin in GC. The data emphasize the critical function of melatonin in several signaling ways by which it may inhibit cancer cell proliferation, decrease chemo-resistance, induce apoptosis as well as limit invasion, angiogenesis, and metastasis. This review provides a resource that identifies some of the mechanisms by which melatonin controls GC enlargement. In light of the findings, melatonin should be considered a novel and testable therapeutic mediator for GC treatment.

Hyperbaric oxygen therapy enhances restoration of physical functional in patients with recurrent glioma: A case report

Patients with recurrent glioblastoma often opt for hypofractionated stereotactic radiosurgery, which can cause various adverse reactions. The pharmacological interventions used to manage these adverse reactions are usually unsatisfactory. The present study reports the case of a patient with recurrent glioblastoma who underwent hyperbaric oxygen therapy followed by immediate hypofractionated stereotactic radiosurgery. Grip strength, isokinetic muscle testing and gait analysis were evaluated during the treatment period, spanning an interval of 7 days in March 2023. Assessments before and after treatment revealed improvements in all three parameters compared with pre-treatment levels. In summary, combining hyperbaric oxygen therapy with hypofractionated stereotactic radiosurgery may enhance muscle strength in patients with recurrent glioblastoma. This treatment approach can lead to significant improvements in gait parameters, promoting better motor coordination. Furthermore, the combined therapy could offer a promising alternative for managing muscle weakness and mobility issues after glioblastoma recurrence.

Value of 11C-Methionine PET Imaging in High-Grade Gliomas: A Narrative Review

11C-Methionine (MET) is a widely utilized amino acid tracer in positron emission tomography (PET) imaging of primary brain tumors. 11C-MET PET offers valuable insights for tumor classification, facilitates treatment planning, and aids in monitoring therapeutic response. Its tracer properties allow better delineation of the active tumor volume, even in regions that show no contrast enhancement on conventional magnetic resonance imaging (MRI). This review focuses on the role of MET-PET in brain glioma imaging. The introduction provides a brief clinical overview of the problems of high-grade and recurrent gliomas. It discusses glioma management, radiotherapy planning, and the difficulties of imaging after chemoradiotherapy (pseudoprogression or radionecrosis). The mechanism of MET-PET is described. Additionally, the review encompasses the application of MET-PET in the context of primary gliomas, addressing its diagnostic precision, utility in tumor classification, prognostic value, and role in guiding biopsy procedures and radiotherapy planning.

Preclinical and clinical advances to overcome hypoxia in glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common adult primary brain tumor. The standard clinical treatment of GBM includes a maximal surgical resection followed by concomitant radiotherapy (RT) and chemotherapy sessions with Temozolomide (TMZ) in addition to adjuvant TMZ cycles. Despite the severity of this protocol, GBM is highly resistant and recurs in almost all cases while the protocol remains unchanged since 2005. Limited-diffusion or chronic hypoxia has been identified as one of the major key players driving this aggressive phenotype. The presence of hypoxia within the tumor bulk contributes to the activation of hypoxia signaling pathway mediated by the hypoxia-inducing factors (HIFs), which in turn activate biological mechanisms to ensure the adaptation and survival of GBM under limited oxygen and nutrient supply. Activated downstream pathways are involved in maintaining stem cell-like phenotype, inducing mesenchymal shift, invasion, and migration, altering the cellular and oxygen metabolism, and increasing angiogenesis, autophagy, and immunosuppression. Therefore, in this review will discuss the recent preclinical and clinical approaches that aim at targeting tumor hypoxia to enhance the response of GBM to conventional therapies along with their results and limitations upon clinical translation.

The Role of Hypoxia and Cancer Stem Cells in Development of Glioblastoma

Glioblastoma multiform (GBM) is recognized as the most malignant brain tumor with a high level of hypoxia, containing a small population of glioblastoma stem like cells (GSCs). These GSCs have the capacity of self-renewal, proliferation, invasion and recapitulating the parent tumor, and are major causes of radio-and chemoresistance of GBM. Upregulated expression of hypoxia inducible factors (HIFs) in hypoxia fundamentally contributes to maintenance and progression of GSCs. Therefore, we thoroughly reviewed the currently acknowledged roles of hypoxia-associated GSCs in development of GBM. In detail, we recapitulated general features of GBM, especially GSC-related features, and delineated essential responses resulted from interactions between GSC and hypoxia, including hypoxia-induced signatures, genes and pathways, and hypoxia-regulated metabolic alterations. Five hypothesized GSC niches are discussed and integrated into one comprehensive concept: hypoxic peri-arteriolar niche of GSCs. Autophagy, another protective mechanism against chemotherapy, is also closely related to hypoxia and is a potential therapeutic target for GBM. In addition, potential causes of therapeutic resistance (chemo-, radio-, surgical-, immuno-), and chemotherapeutic agents which can improve the therapeutic effects of chemo-, radio-, or immunotherapy are introduced and discussed. At last, as a potential approach to reverse the hypoxic microenvironment in GBM, hyperbaric oxygen therapy (HBOT) might be an adjuvant therapy to chemo-and radiotherapy after surgery. In conclusion, we focus on demonstrating the important role of hypoxia on development of GBM, especially by affecting the function of GSCs. Important advantages have been made to understand the complicated responses induced by hypoxia in GBM. Further exploration of targeting hypoxia and GSCs can help to develop novel therapeutic strategies to improve the survival of GBM patients.

Effect of miR‑29a‑3p in exosomes on glioma cells by regulating the PI3K/AKT/HIF‑1α pathway

Exosomes secreted by glioma cells can carry a number of bioactive molecules. As the most abundant noncoding RNA in exosomes, microRNAs (miRNAs) are involved in signaling between tumor cells in a number of ways. In addition, hypoxia is an important feature of the microenvironment of most tumors. The present study investigated the effect of miR‑29a‑3p in glioma exosomes on the proliferation and apoptosis levels of U251 glioma cells under hypoxia. Qualitative PCR results showed that the expression level of miR‑29a‑3p in plasma exosomes of glioma patients was lower than that of normal subjects. By conducting hypoxia experiments in vitro on U251 glioma cells, it was found that the expression level of miR‑29a‑3p decreased following hypoxia, while overexpression of miR‑29a‑3p significantly decreased the proliferation of U251 glioma cells and promoted apoptosis by inhibiting the expression of the antiapoptotic marker Bcl‑2 and increasing the expression of the proapoptotic marker Bax The potential targets of miR‑29a‑3p were predicted by online tools and validated by a dual‑luciferase gene reporter assay. miR‑29a‑3p was found to target and regulate PI3K, which in turn inhibited the activity of the PI3K‑AKT pathway, thereby reducing the expression of hypoxia inducible factor (HIF)‑1α protein. Furthermore, the effects of miR‑29a‑3p on proliferation and apoptosis in glioma cells in those processes could be reversed by the PI3K‑AKT agonist Recilisib. In addition, the inhibitory effect of miR‑29a‑3p on the PI3K/AKT/HIF‑1α regulatory axis could cause a decrease in the expression levels of pyruvate dehydrogenase kinase‑1 and pyruvate dehydrogenase kinase‑2 and eventually lead to a reduction in glycolysis in U251 glioma cells. Similarly, Recilisib slowed the inhibitory effect of miR‑29a‑3p on glycolysis and glycolysis‑related molecules. The results of this study tentatively confirm that miR‑29a‑3p carried by exosomes can be used as a novel diagnostic marker and a potential inhibitory molecule for glioma cells, providing a new theoretical and experimental basis for the precise clinical treatment of glioma.

Hyperbaric Oxygen Therapy as a Complementary Treatment in Glioblastoma-A Scoping Review

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. The mainstay of management for GBM is surgical resection, radiation (RT), and chemotherapy (CT). Even with optimized multimodal treatment, GBM has a high recurrence and poor survival rates ranging from 12 to 24 months in most patients. Recently, relevant advances in understanding GBM pathophysiology have opened new avenues for therapies for recurrent and newly diagnosed diseases. GBM's hypoxic microenvironment has been shown to be highly associated with aggressive biology and resistance to RT and CT. Hyperbaric oxygen therapy (HBOT) may increase anticancer therapy sensitivity by increasing oxygen tension within the hypoxic regions of the neoplastic tissue. Previous data have investigated HBOT in combination with cytostatic compounds, with an improvement of neoplastic tissue oxygenation, inhibition of HIF-1α activity, and a significant reduction in the proliferation of GBM cells. The biological effect of ionizing radiation has been reported to be higher when it is delivered under well-oxygenated rather than anoxic conditions. Several hypoxia-targeting strategies reported that HBOT showed the most significant effect that could potentially improve RT outcomes, with higher response rates and survival and no serious adverse events. However, further prospective and randomized studies are necessary to validate HBOT's effectiveness in the 'real world' GBM clinical practice.

The use of radiosensitizing agents in the therapy of glioblastoma multiforme-a comprehensive review

BACKGROUND

Glioblastoma is the most common malignant brain tumor in human adults. Despite several improvements in resective as well as adjuvant therapy over the last decades, its overall prognosis remains poor. As a means of improving patient outcome, the possibility of enhancing radiation response by using radiosensitizing agents has been tested in an array of studies.

METHODS

A comprehensive review of clinical trials involving radiation therapy in combination with radiosensitizing agents on patients diagnosed with glioblastoma was performed in the National Center for Biotechnology Information's PubMed database.

RESULTS

A total of 96 papers addressing this matter were published between 1976 and 2021, of which 63 matched the subject of this paper. All papers were reviewed, and their findings discussed in the context of their underlining mechanisms of radiosensitization.

CONCLUSION

In the history of glioblastoma treatment, several approaches of optimizing radiation-effectiveness using radiosensitizers have been made. Even though several different strategies and agents have been explored, clear evidence of improved patient outcome is still missing. Tissue-selectiveness and penetration of the blood-brain barrier seem to be major roadblocks; nevertheless, modern strategies try to circumvent these obstacles, using novel sensitizers based on preclinical data or alternative ways of delivery.

Role of hyperbaric oxygen in glioma: a narrative review

Gliomas are common brain mass with a high mortality rate. Patients with gliomas have a severely bad outcome, with an average survive duration less 15 months because of high recurrent rate and being resistant to radio-therapy and chemistry drugs therapy. Hyperbaric oxygen is extensively taken as an adjuvant treatment for various disease conditions. To know the characteristics of hyperbaric oxygen as a remedy for gliomas, we find that, in general, hyperbaric oxygen shows an obviously positive effect on the treatment of gliomas, and it can also relieve the complications caused by postoperative radiotherapy and chemotherapy of gliomas. Whereas, several researches have shown that hyperbaric oxygen promotes glioma progression.

[New Therapeutic Strategies and Future Issues in Hyperbaric Medicine]

Hyperbaric medicine includes two different medical fields: hyperbaric oxygenation (HBO) as emergency and intensive care, and diving medicine. Recent topics in hyperbaric therapy include radiation oncology and regenerative medicine. Of special interest are clinical studies of radiotherapy after HBO that were conducted at some institutes to evaluate its therapeutic effects for cancer patients. A few studies have shown that HBO improves memory disturbance following traumatic brain injury and hypoxic and ischemic events. There is a great possibility that HBO enhances the therapeutic effects of radiotherapy and potentiates regenerative medicine. Randomized controlled trials, however, have indicated the re-examination of its viable treatment effects in some conditions, including decompression illness, carbon monoxide poisoning, and serious soft tissue infection. As recent trends in the treatment of decompression illness have changed on the basis of clinical series, the laws related to diving and caisson work should be amended in the future.

Role of Hyperbaric Oxygenation Plus Hypofractionated Stereotactic Radiotherapy in Recurrent High-Grade Glioma

BACKGROUND

The presence of hypoxic cells in high-grade glioma (HGG) is one of major reasons for failure of local tumour control with radiotherapy (RT). The use of hyperbaric oxygen therapy (HBO) could help to overcome the problem of oxygen deficiency in poorly oxygenated regions of the tumour. We propose an innovative approach to improve the efficacy of hypofractionated stereotactic radiotherapy (HSRT) after HBO (HBO-RT) for the treatment of recurrent HGG (rHGG) and herein report the results of an ad interim analysis.

METHODS

We enrolled a preliminary cohort of 9 adult patients (aged >18 years) with a diagnosis of rHGG. HSRT was administered in daily 5-Gy fractions for 3-5 consecutive days a week. Each fraction was delivered up to maximum of 60 minutes after HBO.

RESULTS

Median follow-up from re-irradiation was 11.6 months (range: 3.2-11.6 months). The disease control rate (DCR) 3 months after HBO-RT was 55.5% (5 patients). Median progression-free survival (mPFS) for all patients was 5.2 months (95%CI: 1.34-NE), while 3-month and 6-month PFS was 55.5% (95%CI: 20.4-80.4) and 27.7% (95%CI: 4.4-59.1), respectively. Median overall survival (mOS) of HBO-RT was 10.7 months (95% CI: 7.7-NE). No acute or late neurologic toxicity >grade (G)2 was observed in 88.88% of patients. One patient developed G3 radionecrosis.

CONCLUSIONS

HSRT delivered after HBO appears to be effective for the treatment of rHGG, it could represent an alternative, with low toxicity, to systemic therapies for patients who cannot or refuse to undergo such treatments.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier NCT03411408.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

Hyperbaric oxygen and radiation therapy: a review

About 5% of cancer patients treated with radiotherapy will have severe late-onset toxicity. Hyperbaric oxygen therapy (HBOT) has been used as a treatment for radiation injuries for decades, with many publications presenting data from small series or individual cases. Moreover, we know that the hypoxic areas of tumours are more resistant to radiation. HBOT increases the oxygen tension in tissues and, theoretically, it should enhance the efficiency of radiotherapy. To better understand how HBOT works, we carried out this bibliographic review. We found Grade B and C evidence that at pressures exceeding 2 absolute atmospheres (ata), HBOT reduced late-onset radiation injuries to the head and neck, bone, prostate and bladder. It also appeared to prevent osteoradionecrosis after exodontia in irradiated areas. Finally, HBOT at 2 ata increased the effectiveness of radiation in head and neck tumours and achieved promising results in the local control of high-grade gliomas.

lncRNA and mRNA signature for prognosis prediction of glioblastoma

Aims: We aimed to find out potential novel biomarkers for prognosis of glioblastoma (GBM). Materials & methods: We downloaded mRNA and lncRNA expression profiles of 169 GBM and five normal samples from The Cancer Genome Atlas and 129 normal brain samples from genotype-tissue expression. We use R language to perform the following analyses: differential RNA expression analysis of GBM samples using 'edgeR' package, survival analysis taking count of single or multiple gene expression level using 'survival' package, univariate and multivariate Cox regression analysis using Cox function plugged in 'survival' package. Gene ontology and Kyoto encyclopedia of genes and genomes pathway analysis were performed using FunRich tool online. Results and conclusion: We obtained differentially DEmRNAs and DElncRNAs in GBM samples. Most prognostically relevant mRNAs and lncRNAs were filtered out. 'GPCR ligand binding' and 'Class A/1' are found to be of great significance. In short, our study provides novel biomarkers for prognosis of GBM.

Hyperbaric oxygen increases glioma cell sensitivity to antitumor treatment with a novel isothiourea derivative in vitro

Glioblastoma (GBM) is the most common primary brain tumor. Tumor hypoxia is a pivotal factor responsible for the progression of this malignant glioma, and its resistance to radiation and chemotherapy. Thus, improved tumor tissue oxygenation may promote greater sensitivity to anticancer treatment. Protein kinase D1 (PKD1) protects cells from oxidative stress, and its abnormal activity serves an important role in multiple malignancies. The present study examined the effects of various oxygen conditions on the cytotoxic potential of the novel isothiourea derivate N,N′-dimethyl-S-(2,3,4,5,6-pentabromobenzyl)- isothiouronium bromide (ZKK-3) against the T98G GBM cell line. ZKK-3 was applied at concentrations of 10, 25 and 50 µM, and cells were maintained under conditions of normoxia, anoxia, hypoxia, hyperbaric oxygen (HBO), hypoxia/hypoxia and hypoxia/HBO. The proliferation and viability of neoplastic cells, and protein expression levels of hypoxia-inducible factor 1α (HIF-1α), PKD1, phosphorylated (p)PKD1 (Ser 916) and pPKD1 (Ser 744/748) kinases were evaluated. Oxygen deficiency, particularly regarding hypoxia, could diminish the cytotoxic effect of ZKK-3 at 25 and 50 µM and improve T98G cell survival compared with normoxia. HBO significantly reduced cell proliferation and increased T98G cell sensitivity to ZKK-3 when compared with normoxia. HIF-1α expression levels were increased under hypoxia compared with normoxia and decreased under HBO compared with hypoxia/hypoxia at 0, 10 and 50 µM ZKK-3, suggesting that HBO improved oxygenation of the cells. ZKK-3 exhibited inhibitory activity against pPKD1 (Ser 916) kinase; however, the examined oxygen conditions did not appear to significantly influence the expression of this phosphorylated form in cells treated with the tested compound. Regarding pPKD1 (Ser 744/748), a significant difference in expression was observed only for cells treated with 10 µM ZKK-3 and hypoxia/hypoxia compared with normoxia. However, there were significant differences in the expression levels of both phosphorylated forms of PKD1 under different oxygen conditions in the controls. In conclusion, the combination of isothiourea derivatives and hyperbaric oxygenation appears to be a promising therapeutic approach for malignant glioma treatment.

Therapeutic effect of combined hyperbaric oxygen and radiation therapy for single brain metastasis and its influence on osteopontin and MMP-9

The present study aimed to investigate the therapeutic effect of combined hyperbaric oxygen and radiation therapy for the treatment of single brain metastasis (SBM), as well as its influence on osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9). A total of 86 patients with SBM were admitted to Hongqi Hospital from January 2013 to January 2016 and those included within the study were randomly divided into two groups. The control group was only treated with whole brain radiotherapy, while the observation group was treated with hyperbaric oxygenation combined with whole brain radiotherapy. OPN and MMP-9 expression was measured in each group by ELISA and the results prior to and following treatment were compared. The total effective rate (patients with complete remission, partial remission or stabilized lesions) in the observation group (95.3%) was significantly increased compared with the control group (67.4%). However, the OPN and MMP-9 protein levels observed in the observation group were significantly reduced compared with the control group (P<0.05). In addition, the quality of life and the incidence of adverse reactions in the observation group were significantly improved compared with the control group (P<0.05). For patients with SBM, hyperbaric oxygenation combined with radiotherapy may improve the efficiency of treatment and should be considered for further investigation and use within a clinical setting.

Hyperbaric oxygen therapy as adjunctive strategy in treatment of glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common type of malignant intracranial tumor in adults. Tumor tissue hypoxia, high mitotic rate, and rapid tumor spread account for its poor prognosis. Hyperbaric oxygen therapy (HBOT) may improve the sensitivity of radio-chemotherapy by increasing oxygen tension within the hypoxic regions of the neoplastic tissue. This review summarizes the research of HBOT applications within the context of experimental and clinical GBM. Limited clinical trials and preclinical studies suggest that radiotherapy immediately after HBOT enhances the effects of radiotherapy in some aspects. HBOT also is able to strengthen the anti-tumor effect of chemotherapy when applied together. Overall, HBOT is well tolerated in the GBM patients and does not significantly increase toxicity. However, HBOT applied by itself as curative strategy against GBM is controversial in preclinical studies and has not been evaluated rigorously in GBM patients. In addition to HBOT favorably managing the therapeutic resistance of GBM, future research needs to focus on the multimodal or cocktail approaches to treatment, as well as molecular strategies targeting GBM stem cells.

Hyperbaric oxygen treatment sensitizes gastric cancer cells to melatonin-induced apoptosis through multiple pathways

Although extensive efforts have been made in recent decades to treat advanced gastric cancer with comprehensive therapy based on chemotherapy, effective anti-gastric cancer therapeutics are still lacking in the clinics. Therefore, potent novel anti-gastric cancer ways are greatly needed. Here, we explored hyperbaric oxygen treatment as a novel and effective adjuvant treatment method which has anti-gastric cancer effects when used together with melatonin. When performed together with MLT, HBO effectively inhibited tumorigenicity of gastric cancer through selectively inducing a robust tumor suppressive apoptosis response. Mechanistic studies revealed that the sensitizing effect of hyperbaric oxygen is due to decreased ratio of Bcl-2/Bax, increased level of p53, cleaved Caspase3, GRP78, CHOP, and LC3. These results give a vivid picture that classic apoptosis pathways including mitochondrial pathway, tumor suppressive endoplasmic reticulum stress (ERS), and autophagy are all involved in the process. From the preliminary results got from the current study, we identified that HBO sensitizes human gastric cancer cells to MLT-induced apoptosis through a variety of complicated molecular mechanisms. HBO may provide a novel candidate supplemental treatment method for further development of potential anti-gastric cancer therapeutics. The combination of HBO and MLT could be a promising treatment for advanced gastric cancer.

Perfluorocarbon emulsions radiosensitise brain tumors in carbogen breathing mice with orthotopic GL261 gliomas

Background

Tumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO₂ in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy.

Aim

To investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O₂ and 5%CO₂).

Results

PFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone.

Conclusion

IV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors.