Management of Glioblastoma Multiforme in a Patient Treated With Ketogenic Metabolic Therapy and Modified Standard of Care: A 24-Month Follow-Up

Health Benefits of Intermittent Fasting

We propose that intermittent fasting (time-restricted eating), in agreement with the conclusions of other biologists, as revealed in recent publications, promotes the achievement of numerous health benefits including the extension of human and animal lifespans. Background: There is evidence, obtained both with animal model systems and with humans, that intermittent fasting has health benefits. These benefits include extended longevity, weight loss, and counteracting various disease conditions. Such procedures positively influence the benefits of human tissue-specific microbiomes and minimize the consequences of organellar apoptosis. Key Messages: In this review, we attempt to summarize the predominant evidence, published in the scientific literature, relevant to the conclusions that in general, and in many specific instances, intermittent fasting has long-term benefits to animals, including humans, with respect to overall and specific organismal health and longevity.

Ketogenic metabolic therapy in conjunction with standard treatment for glioblastoma: A case report

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. The standard of care consists of surgical resection and concurrent chemoradiation, followed by adjuvant temozolomide chemotherapy. This protocol is associated with a median survival of 12-15 months, and <5% of patients survive >3 years. Ketogenic metabolic therapy (KMT) targets cancer cell metabolism by restricting glucose availability and evoking differential stress resistance and sensitization, which may augment the standard treatments and lead to therapeutic benefit. The present study reports the case of a 64-year-old woman with isocitrate dehydrogenase (IDH)-wildtype GBM who pursued the standard treatment protocol in conjunction with an intensive, multimodal KMT program for 3 years. The KMT program consisted of a series of prolonged (7-day, fluid-only) fasts, which were specifically timed to maximize the tolerability and efficacy of the standard treatments, combined with a time-restricted ketogenic diet on all other days. During the first and second treatment years the patient sustained a glucose ketone index (GKI) of 1.65 and 2.02, respectively, which coincided with complete clinical improvement, a healthy body-mass index and a high quality of life, with no visible progressive tumour detected on imaging at the end of the second year. In the setting of the death of an immediate family member leading to increased life stress, slightly relaxed KMT adherence, and a higher GKI of 3.20, slow cancer progression occurred during the third year. The adverse effects attributed to KMT were mild. Despite the limitations of this case report, it highlights the feasibility of implementing the standard treatment protocol for GBM in conjunction with an intensive, long-term, multimodal and specifically timed KMT program, the potential therapeutic efficacy of which may depend upon achieving as low a GKI as possible.

Metformin shows anti-neoplastic properties by inhibition of oxidative phosphorylation and glycolysis in epidermolysis bullosa-associated aggressive cutaneous squamous cell carcinoma

BACKGROUND

While most cutaneous squamous cell carcinomas (cSCCs) are treatable, certain high-risk cSCCs, such as those in recessive dystrophic epidermolysis bullosa (RDEB) patients, are particularly aggressive. Owing to repeated wounding, inflammation and unproductive healing, RDEB patients have a 68% cumulative risk of developing life-threatening cSCCs by the age of 35, and a 70% risk of death by the age of 45. Despite aggressive treatment, cSCC represents the leading cause of premature mortality in these patients, highlighting an unmet clinical need. Increasing evidence points to a role of altered metabolism in the initiation and maintenance of cSCC, making metabolism a potential therapeutic target.

OBJECTIVES

We sought to determine the feasibility of targeting tumour cell energetics as a strategy to selectively hinder the growth advantage of aggressive cSCC.

METHODS

We evaluated the cell energetics profiles of RDEB-SCC cells by analysing available gene expression data against multiple gene signatures and single-gene targets linked to metabolic reprogramming. Additionally, we employed real-time metabolic profiling to measure glycolysis and respiration in these cells. Furthermore, we investigated the anti-neoplastic properties of the metformin against human and murine high-risk cSCCs in vitro and in vivo.

RESULTS

Gene expression analyses highlighted a divergence in cell energetics profiles between RDEB-SCC and non-malignant RDEB keratinocytes, with tumour cells demonstrating enhanced respiration and glycolysis scores. Real-time metabolic profiling supported these data and additionally highlighted a metabolic plasticity of RDEB-SCC cells. Against this background, metformin exerted an anti-neoplastic potential by hampering both respiration and glycolysis, and by inhibiting proliferation in vitro. Metformin treatment in an analogous model of fast-growing murine cSCC resulted in delayed tumour onset and slower tumour growth, translating to a 29% increase in median overall survival.

CONCLUSIONS

Our data indicate that metformin exerts anti-neoplastic properties in aggressive cSCCs that exhibit high-risk features by interfering with respiration and glycolytic processes.

The Role of Ketone Bodies in Treatment Individualization of Glioblastoma Patients

Glioblastoma is the most common and aggressive primary brain tumor in adults. According to the 2021 WHO CNS, glioblastoma is assigned to the IDH wild-type classification, fulfilling the specific characteristic histopathology. We have conducted a prospective observational study to identify the glucose levels, ketone bodies, and the glucose-ketone index in three groups of subjects: two tumoral groups of patients with histopathological confirmation of glioblastoma (9 male patients, 7 female patients, mean age 55.6 years old) or grade 4 astrocytoma (4 male patients, 2 female patients, mean age 48.1 years old) and a control group (13 male patients, 9 female patients, mean age 53.9 years old) consisting of subjects with no personal pathological history. There were statistically significant differences between the mean values of glycemia (p value = 0.0003), ketones (p value = 0.0061), and glucose-ketone index (p value = 0.008) between the groups of patients. Mortality at 3 months in glioblastoma patients was 0% if the ketone levels were below 0.2 mM and 100% if ketones were over 0.5 mM. Patients with grade 4 astrocytoma and the control subjects all presented with ketone values of less than 0.2 mM and 0.0% mortality. In conclusion, highlighting new biomarkers which are more feasible to determine such as ketones or glucose-ketone index represents an essential step toward personalized medicine and survival prolongation in patients suffering from glioblastoma and grade 4 astrocytoma.

Current knowledges in pharmaconutrition: "Ketogenics" in pediatric gliomas

Brain tumors account for 20-25% of pediatric cancers. The most frequent type of brain tumor is Glioma from grade I to grade IV according to the rate of malignancy. Current treatments for gliomas use chemotherapy, radiotherapy, tyrosine kinase inhibitors, monoclonal antibodies and surgery, but each of the treatment strategies has several serious side effects. Therefore, to improve treatment efficacy, it is necessary to tailor therapies to patient and tumor characteristics, using appropriate molecular targets. An increasingly popular strategy is pharmaconutrition, which combines a tailored pharmacological treatment with a diet designed to synergize the effects of drugs. In this review we deal in the molecular mechanisms, the epigenetic effects and modulation of the oxidative stress pathway of ketogenic diets, that underlie its possible role, in the treatment of infantile gliomas, as a complementary approach to conventional cancer therapy.

RXR Agonists Enhance Lenalidomide Anti-Myeloma Activity and T Cell Functions while Retaining Glucose-Lowering Effect

Retinoid X receptor (RXR) heterodimerizes with the PPAR nuclear hormone receptor and regulates its downstream events. We investigated the effects of RXR agonists (LG100754, bexarotene, AGN194204, and LG101506) on lenalidomide's anti-myeloma activity, T cell functions, and the level of glucose and lipids in vivo. Genetic overexpression and CRISPR/Cas9 knockout experiments were conducted in multiple myeloma (MM) cell lines and Jurkat T cell lines to determine the roles of CRBN in RXR-agonist mediated effects. A xenograft mouse model of MM was established to determine the combination effect of LG100754 and lenalidomide. The combination of RXR agonists and lenalidomide demonstrated synergistic activity in increasing CRBN expression and killing myeloma cells. Mechanistically, the RXR agonists reduced the binding of PPARs to the CRBN promoter, thereby relieving the repressor effect of PPARs on CRBN transcription. RXR agonists downregulated the exhaustion markers and increased the activation markers of Jurkat T cells and primary human T cells. Co-administration of LG100754 and lenalidomide showed enhanced anti-tumor activity in vivo. LG100754 retained its glucose- and lipid-lowering effects. RXR agonists demonstrate potential utility in enhancing drug sensitivity and T-cell function in the treatment of myeloma.

Role of nutritional adjuncts in the management of gliomas: A systematic review of literature

BACKGROUND

A variety of dietary adjuncts are known to affect the pathophysiology of glioma, making them a potential therapeutic adjunct to standard of care. We systematically reviewed clinical outcomes in glioma patients treated with one or more nutritional adjunct and/or an antimetabolite drug.

METHODOLOGY

A systematic review of the literature following PRISMA guidelines was performed using Pubmed from inception till February 2023. In total, 22 manuscripts on nutrition representing 828 patients were included in the review. Statistical analyses were performed to compare the outcomes of various adjuncts.

RESULTS

The median overall survival (OS) increased for newly diagnosed (21 months) and recurrent cases (10 months) when compared to historical data. For newly diagnosed cases, a ketogenic diet had the highest median OS of all the adjuncts (42.6 months) while in recurrent cases, a low copper diet coupled with 1 g penicillamine had the highest median OS (18.5 months). However, no statistically significant difference was observed in OS or progression-free survival (PFS) of newly diagnosed or recurrent gliomas.

CONCLUSION

While nutritional adjuncts may offer a therapeutic benefit in the treatment of glioma, more human subject research is needed to derive meaningful conclusions.

Ketogenic therapies for glioblastoma: Understanding the limitations in transitioning from mice to patients

Glioblastoma Multiforme is an aggressive brain cancer affecting children and adults frequently resulting in a short life expectancy. Current cancer therapies include surgery and radiation followed by chemotherapy, which due to their ineffectiveness, requires repeated exposure to the same therapies. Since the 1990s, researchers and doctors have explored other therapies, such as diet therapies, to aid in combating gliomas. The ketogenic diet has gained popularity due to Otto Warburg's theory that tumor cells prefer "aerobic glycolysis" and cannot metabolize ketones. The inability of gliomas to use ketones provides an excellent opportunity to weaken the tumor while protecting healthy cells during cancer treatments. This review will examine some of the current research using the ketogenic diet as a form of cancer therapy to determine if this intervention is manageable and effective in patients with glioblastoma. Peer-reviewed articles from 2009 to 2019 were used. The primary objective is to distinguish differences between pre-clinical and clinical research to determine if the ketogenic diet is reproducible from mouse models into humans to determine its effectiveness. The analysis revealed several limitations of the ketogenic diet as an intervention. The effectiveness is more robust in mice than in human studies. Furthermore, tolerability is marginally supported in human studies requiring more reproducible research to validate that the intervention is manageable and effective in patients with glioblastoma.

The Ketogenic Diet: Considerations for Cancer Survivorship

PURPOSE OF REVIEW

This article aims to evaluate the current practice of the ketogenic diet (KD) in oncology by discussing feasibility, impact on quality of life, and implications for dietetic practice. Articles discussed were selected based on an adult oncology population with emphasis on publications from the last 5 years.

RECENT FINDINGS

There is a paucity of randomized prospective trials and articles reviewed were heterogeneous in nature, limiting the ability to draw conclusions about the KDs role in cancer care and survivorship. Despite the lack of evidence, patients with cancer are interested in KD. The authors highlight barriers to supporting implementation of KD and recommend the inclusion of a registered dietitian with experience in KD to ensure safety and support the nutrition goals of patients with cancer. Thorough, well-designed randomized control trials are needed to elucidate the potential advantages of this diet therapy in cancer care and survivorship.

Combining locoregional CAR-T cells, autologous + allogeneic tumor lysate vaccination and levamisole in treatment of glioblastoma

Glioblastoma multiforme (GBM) is an aggressive brain malignancy and harbors a microenvironment limiting immune cells activity. CAR-T cells are being tested in the treatment of cancers and there exist reports which demonstrate dramatic regression of multicentric GBMs following intrathecal treatment with CAR-T cells. In this article, a triple approach for immune treatment of GBM is proposed. First, GBM tumor specimens for each patient will be saved and cultured to obtain tumor lysates. Then, levamisole will be applied, which possesses immunostimulating, anti-glycolytic, and anti-angiogenic features. Following priming the immune system, GBM patients will be injected with lysates of their own tumor cells plus lysates from a GBM cell line, U251. After 3 months of this treatment, CAR-T cells (transduced with IL13Rα2-CAR) will be applied via intratumoral approach. As such, genetically-modified and native immunocytes may 'meet' in the vicinity of deeply-invading tumor cells and demonstrate greater efficacy via cell-cell interactions. By this, a self-propagating cyclic process - a cancer-immunity cycle - may be initiated to eradicate cancer cells.

Novel Derivatives of Tetrahydrobenzo (g) Imidazo[α-1,2] Quinoline Induce Apoptosis Via ROS Production in the Glioblastoma Multiforme Cells, U-87MG

BACKGROUND

Despite newer therapeutic approaches against glioblastoma multiforme (GBM), the severely poor prognosis and treatment resistance are still disadvantages that slow down the patient's recovery process. Consistent with the need to develop more effective and optimized therapies to control GBM cell growth, the effects of a new series of tetrahydrobenzo(g)imidazo[α-1,2]quinolone derivatives on GBM cell growth and the underlying mechanism is investigated in the current study.

METHODS

U-87MG cell line, glioblastoma multiforme and normal skin fibroblast cell line, AGO1522 were used to study the anticancer effects of 5 derivatives of tetrahydrobenzo(g)imidazo[α-1,2]quinolone and paclitaxel as a standard drug. The cytotoxic effect on cell growth was assessed using the MTT assay. Annexin V FITC staining and PI staining were applied to detect apoptosis and cell cycle distribution using flow cytometry. The extent of reactive oxygen species (ROS) formation was assessed using the fluorescent probe 7-dichlorofluorescin diacetate and caspase-3 activity using the colorimetric assay kit.

RESULTS

Among the 5 derivatives of tetrahydrobenzo(g)imidazo[α-1,2]quinolone, the 5c derivative (5-(6-bromo-2-chloroquinolin-3-yl)-9a-hydroxy-8,8-dimethyl-4-Nitro-2,3,5,5a,7,8,9,9a-octahydroimidazo[α-1,2]quinoline-6(1H)) showed the strongest cytotoxic effect on U-87MG cells in a time and Dose-dependent manner compared to the other derivatives and paclitaxel. The IC50 (11.91 M) of the 5c derivative induced apoptosis accompanied by a significant increase in sub-G1 and super-G2 phases of U-87MG cells. The increased level of cellular ROS and caspase 3 activity after treatment of U-87MG cells with 5c derivative was significant compared to untreated cells.

CONCLUSION

Our data provide insights into the potent anticancer effects of the 5c-derivative of tetrahydrobenzo(g)imidazo[α-1,2]quinolone on GBM cells via the caspase-dependent apoptotic pathway, which may merit further attention.

Feasibility and Safety of a Combined Metabolic Strategy in Glioblastoma Multiforme: A Prospective Case Series

Background

Glioblastoma multiforme (GBM) may be susceptible to metabolic strategies such as fasting and ketogenic diets, which lower blood glucose and elevate ketones. Combining these two strategies may be an ideal approach for sustaining a potentially therapeutic glucose ketone index (GKI). In this prospective case series, we observed whether a combined metabolic strategy was feasible, safe, and capable of sustaining a GKI <6 in patients with GBM.

Methods

We provided recommendations and guidelines to 10 GBM patients at various stages of tumour progression and treatment that enabled them to complete a 5–7-day fast every 1–2 months combined with a modified ketogenic diet during the intervening weeks. Patients monitored their blood glucose and ketone levels and body weight. Adverse effects were assessed.

Results

Patients completed a mean of 161 ± 74 days of the combined metabolic strategy, with 34 ± 18 (21%) days of prolonged fasting (mean fast duration: 6.0 ± 1.4 days) and 127 ± 59 (79%) days on the ketogenic diet. The mean GKI for all 10 patients was 3.22 (1.28 during the fasts, 5.10 during the ketogenic diet). Body weight decreased by 8.4 ± 6.9 kg (11.2% decrease in baseline weight). The most common adverse effects attributed to the fasts and ketogenic diet were fatigue, irritability, and feeling lightheaded. The metabolic strategy did not interfere with standard oncological treatments.

Conclusion

This is the first study to observe the feasibility and safety of repeated, prolonged fasting combined with a modified ketogenic diet in patients with GBM. Using minimal support, patients maintained the combined metabolic strategy for 5–6 months while sustaining a potentially therapeutic mean GKI of 3.22. Weight loss was considerable. Adverse effects attributed to the metabolic strategy were mild, and it did not interfere with standard oncological treatments. Study Registration: This study is registered on the Australia New Zealand Clinical Trials Registry, number ACTRN12620001310954. The study was registered on 4 December 2020.

Ketogenic Diet in the Treatment of Gliomas and Glioblastomas

In recent years, scientific interest in the use of the ketogenic diet (KD) as a complementary approach to the standard cancer therapy has grown, in particular against those of the central nervous system (CNS). In metabolic terms, there are the following differences between healthy and neoplastic cells: neoplastic cells divert their metabolism to anaerobic glycolysis (Warburg effect), they alter the normal mitochondrial functioning, and they use mainly certain amino acids for their own metabolic needs, to gain an advantage over healthy cells and to lead to a pro-oncogenetic effect. Several works in literature speculate which are the molecular targets of KD used against cancer. The following different mechanisms of action will be explored in this review: metabolic, inflammatory, oncogenic and oncosuppressive, ROS, and epigenetic modulation. Preclinical and clinical studies on the use of KD in CNS tumors have also increased in recent years. An interesting hypothesis emerged from the studies about the possible use of a ketogenic diet as a combination therapy along with chemotherapy (CT) and radiotherapy (RT) for the treatment of cancer. Currently, however, clinical data are still very limited but encouraging, so we need further studies to definitively validate or disprove the role of KD in fighting against cancer.

Metabolic management of microenvironment acidity in glioblastoma

Glioblastoma (GBM), similar to most cancers, is dependent on fermentation metabolism for the synthesis of biomass and energy (ATP) regardless of the cellular or genetic heterogeneity seen within the tumor. The transition from respiration to fermentation arises from the documented defects in the number, the structure, and the function of mitochondria and mitochondrial-associated membranes in GBM tissue. Glucose and glutamine are the major fermentable fuels that drive GBM growth. The major waste products of GBM cell fermentation (lactic acid, glutamic acid, and succinic acid) will acidify the microenvironment and are largely responsible for drug resistance, enhanced invasion, immunosuppression, and metastasis. Besides surgical debulking, therapies used for GBM management (radiation, chemotherapy, and steroids) enhance microenvironment acidification and, although often providing a time-limited disease control, will thus favor tumor recurrence and complications. The simultaneous restriction of glucose and glutamine, while elevating non-fermentable, anti-inflammatory ketone bodies, can help restore the pH balance of the microenvironment while, at the same time, providing a non-toxic therapeutic strategy for killing most of the neoplastic cells.

Glucose deprivation reduces proliferation and motility, and enhances the anti-proliferative effects of paclitaxel and doxorubicin in breast cell lines in vitro

Background

Breast cancer chemotherapy with high dose alkylating agents is severely limited by their collateral toxicity to crucial normal tissues such as immune and gut cells. Taking advantage of the selective dependence of cancer cells on high glucose and combining glucose deprivation with these agents could produce therapeutic synergy.

Methods

In this study we examined the effect of glucose as well as its deprivation, and antagonism using the non-metabolized analogue 2-deoxy glucose, on the proliferation of several breast cancer cell lines MCF7, MDA-MB-231, YS1.2 and pII and one normal breast cell line, using the MTT assay. Motility was quantitatively assessed using the wound healing assay. Lactate, as the end product of anaerobic glucose metabolism, secreted into culture medium was measured by a biochemical assay. The effect of paclitaxel and doxorubicin on cell proliferation was tested in the absence and presence of low concentrations of glucose using MTT assay.

Results

In all cell lines, glucose supplementation enhanced while glucose deprivation reduced both their proliferation and motility. Lactate added to the medium could substitute for glucose. The inhibitory effects of paclitaxel and doxorubicin were significantly enhanced when glucose concentration was decreased in the culture medium, requiring 1000-fold lesser concentration to achieve a similar degree of inhibition to that seen in glucose-containing medium.

Conclusion

Our data show that a synergy was obtained by combining paclitaxel and doxorubicin with glucose reduction to inhibit cancer cell growth, which in vivo, might be achieved by applying a carbohydrate-restricted diet during the limited phase of application of chemotherapy; this could permit a dose reduction of the cytotoxic agents, resulting in greater tolerance and lesser side effects.

Restricted Ketogenic Diet Therapy for Primary Lung Cancer With Metastasis to the Brain: A Case Report

A high-fat and low-carbohydrate diet was administered as a complementary and alternative therapy to a 54-year-old man suffering from non-small-cell lung cancer (NSCLC) with brain metastasis. Three months after the cessation of chemotherapy and radiotherapy, a ketogenic diet (KD) was initiated. This approach was an attempt to stabilize the disease progression after chemotherapy and radiotherapy. Computed tomography following radiation and chemotherapy showed a reduction in the right frontal lobe lesion from 5.5 cm × 6.2 cm to 4 cm × 2.7 cm, while the mass in the upper-right lung lobe reduced from 6.0 cm × 3.0 cm to 2.0 × 1.8 cm. Two years after KD initiation and without any other therapeutic intervention, the right frontal lobe lesion calcified and decreased in size to 1.9 cm × 1.0 cm, while the size of the lung mass further decreased to 1.7 cm × 1.0 cm. The size of the brain and lung lesion remained stable after nine years of KD therapy. However, dyslipidemia developed after this time which led to the discontinuation of the diet. No tumor relapse or health issues occurred for two years after the discontinuation of the diet. This case report indicates that the inclusion of ketogenic metabolic therapy following radiation and chemotherapy is associated with better clinical and survival outcomes for our patient with metastatic NSCLC.

Research Involvement in a Group of Registered Dietitian Nutritionists Specializing in Ketogenic Diet Therapies for Epilepsy

BACKGROUND

There is a growing need for studies on ketogenic diet (KD) therapies. Registered dietitian nutritionists (RDNs) should lead efforts to better understand nutritional risks and benefits of the KD to inform evidence-based practices.

OBJECTIVE

The purpose of this study was to explore participation in research amongst RDNs practicing in KD therapies for epilepsy and identify barriers to participation.

DESIGN

This cross-sectional study collected professional experience, research involvement and output, and perceived barriers to conducting research.

PARTICIPANTS/SETTING

This study surveyed 66 RDNs practicing in KD therapies for epilepsy.

MAIN OUTCOME MEASURE

Research involvement was assessed using the Dietitian Research Involvement Survey (DRIS) score. Research output was reported as type and number of publications. Barriers to research included lack of time, resources, administrative support, training, and/or skill.

STATISTICAL ANALYSES

Data were summarized using descriptive statistics such as means and standard deviations, medians and interquartile ranges, counts and percentages, as appropriate.

RESULTS

The median DRIS score was 31 out of 60 (range: 16-60). Thirty-two participants (48.5%) reported publishing or presenting data, and only 13.6% published a manuscript on ketogenic diet therapies as a leading author. The main barriers to participating in research were insufficient time (83.3%), insufficient funding (81.8%), and priority of work (70.8%). Research involvement scores were not affected by lack of time and resources, however scores were lower in RDNs reporting lack of interest, training, and skill in research.

CONCLUSIONS

While ketogenic RDNs participated in research, most were not leading projects or publications. To increase research involvement amongst RDNs, focus should include overcoming structural barriers while facilitating knowledge acquisition for those lower on the research continuum.

Cancer-Associated Microbiota: From Mechanisms of Disease Causation to Microbiota-Centric Anti-Cancer Approaches

Helicobacter pylori infection is the only well-established bacterial cause of cancer. However, due to the integral role of tissue-resident commensals in maintaining tissue-specific immunometabolic homeostasis, accumulated evidence suggests that an imbalance of tissue-resident microbiota that are otherwise considered as commensals, can also promote various types of cancers. Therefore, the present review discusses compelling evidence linking tissue-resident microbiota (especially gut bacteria) with cancer initiation and progression. Experimental evidence supporting the cancer-causing role of gut commensal through the modulation of host-specific processes (e.g., bile acid metabolism, hormonal effects) or by direct DNA damage and toxicity has been discussed. The opportunistic role of commensal through pathoadaptive mutation and overcoming colonization resistance is discussed, and how chronic inflammation triggered by microbiota could be an intermediate in cancer-causing infections has been discussed. Finally, we discuss microbiota-centric strategies, including fecal microbiota transplantation, proven to be beneficial in preventing and treating cancers. Collectively, this review provides a comprehensive understanding of the role of tissue-resident microbiota, their cancer-promoting potentials, and how beneficial bacteria can be used against cancers.

Glucose Influences the Response of Glioblastoma Cells to Temozolomide and Dexamethasone

Objective

Current research indicates that weakness of glucose metabolism plays an important role in silencing of invasiveness and growth of hypoxic tumors such as GBM. Moreover, there are indications that DXM, frequently used in treatment, may support GBM energy metabolism and provoke its recurrence.

Methods

We carried out in vitro experiments on the commercial T98G cell line and two primary GBM lines (HROG02, HROG17) treated with TMZ and/or DXM in physiological oxygen conditions for GBM (2.5% oxygen) and for comparison, in standard laboratory conditions (20% oxygen). The influence of different glucose levels on selected malignancy features of GBM cells-cellular viability and division, dynamic of cell culture changes, colony formation and concentration of InsR have been elevated.

Results

Under 2.5% oxygen and high glucose concentration, an attenuated cytotoxic effect of TMZ and intensification of malignancy features in all glioblastoma cell lines exposed to DXM was seen. Furthermore, preliminary retrospective analysis to assess the correlation between serum glucose levels and Ki-67 expression in surgical specimens derived from patients with GBM (IV) treated with radio-chemotherapy and prophylactic DXM therapy was performed.

Conclusion

The data suggest a link between the in vitro study results and clinical data. High glucose can influence on GBM progression through the promotion of the following parameters: cell viability, dispersal, InsR expression and cell proliferation (Ki-67). However, this problem needs more studies and explain the mechanism of action studied drugs.

Ketogenic Diets and their Therapeutic Potential on Breast Cancer: A Systemic Review

Breast cancer remains a major cause of morbidity and mortality in women, and there is still a lack of complementary approaches to significantly improve the efficacy of standard therapies. For many kinds of cancers, the usual standard care is the combination of surgery, radiation, and chemotherapy. However, this standard therapy is not effective alone. Therefore, new approaches that increase therapeutic effectiveness are urgently needed. The ketogenic diet is a novel therapeutic approach for certain types of cancers, as indicated by several preclinical and clinical evidences. The ketogenic diet, which consists of a high-fat, low-carbohydrate diet with adequate protein, appears to sensitize most cancers to standard therapy by utilizing the reprogrammed metabolism of cancer cells, making it a promising candidate for adjuvant cancer treatment. The majority of preclinical and clinical studies argue that the use of a ketogenic diet in combination with standard therapies is based on its potential to improve the antitumor effects of conventional chemotherapy, its overall good safety and tolerability, and quality of life improvement. According to new evidence, a ketogenic diet lowers the level of glucose and insulin in the blood, which are necessary for tumor growth. Thus, the ketogenic diet has emerged as a potential treatment option for a variety of cancers, including breast cancer. Besides, implementation of a Ketogenic diet in the clinic could improve progression-free and overall survival for patients with breast cancer. This review summarizes the composition and metabolism of ketogenic diets and their potential mechanisms in breast carcinogenesis in addition to their therapeutic potential on breast cancer.

Metabolic therapy and bioenergetic analysis: The missing piece of the puzzle

BACKGROUND

Aberrant metabolism is recognized as a hallmark of cancer, a pillar necessary for cellular proliferation. Regarding bioenergetics (ATP generation), most cancers display a preference not only toward aerobic glycolysis ("Warburg effect") and glutaminolysis (mitochondrial substrate level-phosphorylation) but also toward other metabolites such as lactate, pyruvate, and fat-derived sources. These secondary metabolites can assist in proliferation but cannot fully cover ATP demands.

SCOPE OF REVIEW

The concept of a static metabolic profile is challenged by instances of heterogeneity and flexibility to meet fuel/anaplerotic demands. Although metabolic therapies are a promising tool to improve therapeutic outcomes, either via pharmacological targets or press-pulse interventions, metabolic plasticity is rarely considered. Lack of bioenergetic analysis in vitro and patient-derived models is hindering translational potential. Here, we review the bioenergetics of cancer and propose a simple analysis of major metabolic pathways, encompassing both affordable and advanced techniques. A comprehensive compendium of Seahorse XF bioenergetic measurements is presented for the first time.

MAJOR CONCLUSIONS

Standardization of principal readouts might help researchers to collect a complete metabolic picture of cancer using the most appropriate methods depending on the sample of interest.

The use of ketogenic diets in cancer patients: a systematic review

Ketogenic diets are a widely known, yet controversial treatment for cancer patients. In this review, we summarize the clinical evidence for anti-tumor effects, as well as the effects on anthropometry, quality of life, adverse events and adherence in cancer patients. In April 2019, a systematic search was conducted searching five electronic databases (EMBASE, Cochrane, PsychInfo, CINAHL and Medline) to find studies analyzing the use, effectiveness and potential harm of a ketogenic diet in cancer patients of any age as sole or complementary therapy. From all 19.211 search results, 46 publications concerning 39 studies with 770 patients were included in this systematic review. The therapy concepts included all forms of diets with reduced carbohydrate intake, that aimed to achieve ketosis for patients with different types of cancer. Most studies had a low quality, high risk of bias and were highly heterogeneous. There was no conclusive evidence for anti-tumor effects or improved OS. The majority of patients had significant weight loss and mild to moderate side effects. Adherence to the diet was rather low in most studies. Due to the very heterogeneous results and methodological limitations of the included studies, clinical evidence for the effectiveness of ketogenic diets in cancer patients is still lacking.

Ketogenic Diet for Cancer: Critical Assessment and Research Recommendations

Despite remarkable improvements in screening, diagnosis, and targeted therapies, cancer remains the second leading cause of death in the United States. It is increasingly clear that diet and lifestyle practices play a substantial role in cancer development and progression. As such, various dietary compositions have been proposed for reducing cancer risk and as potential adjuvant therapies. In this article, we critically assess the preclinical and human trials on the effects of the ketogenic diet (KD, i.e., high-fat, moderate-to-low protein, and very-low carbohydrate content) for cancer-related outcomes. The mechanisms underlying the hypothesized effects of KD, most notably the Warburg Effect, suggest that restricting carbohydrate content may impede cancer development and progression via several pathways (e.g., tumor metabolism, gene expression). Overall, although preclinical studies suggest that KD has antitumor effects, prolongs survival, and prevents cancer development, human clinical trials are equivocal. Because of the lack of high-quality clinical trials, the effects of KD on cancer and as an adjunctive therapy are essentially unknown. We propose a set of research recommendations for clinical studies examining the effects of KD on cancer development and progression.

Ketogenic Diet in Cancer Prevention and Therapy: Molecular Targets and Therapeutic Opportunities

Although cancer is still one of the most significant global challenges facing public health, the world still lacks complementary approaches that would significantly enhance the efficacy of standard anticancer therapies. One of the essential strategies during cancer treatment is following a healthy diet program. The ketogenic diet (KD) has recently emerged as a metabolic therapy in cancer treatment, targeting cancer cell metabolism rather than a conventional dietary approach. The ketogenic diet (KD), a high-fat and very-low-carbohydrate with adequate amounts of protein, has shown antitumor effects by reducing energy supplies to cells. This low energy supply inhibits tumor growth, explaining the ketogenic diet's therapeutic mechanisms in cancer treatment. This review highlights the crucial mechanisms that explain the ketogenic diet's potential antitumor effects, which probably produces an unfavorable metabolic environment for cancer cells and can be used as a promising adjuvant in cancer therapy. Studies discussed in this review provide a solid background for researchers and physicians to design new combination therapies based on KD and conventional therapies.

Ketogenic Metabolic Therapy, Without Chemo or Radiation, for the Long-Term Management of IDH1-Mutant Glioblastoma: An 80-Month Follow-Up Case Report

Background: Successful treatment of glioblastoma (GBM) remains futile despite decades of intense research. GBM is similar to most other malignant cancers in requiring glucose and glutamine for growth, regardless of histological or genetic heterogeneity. Ketogenic metabolic therapy (KMT) is a non-toxic nutritional intervention for cancer management. We report the case of a 32-year-old man who presented in 2014 with seizures and a right frontal lobe tumor on MRI. The tumor cells were immunoreactive with antibodies to the IDH1 (R132H) mutation, P53 (patchy), MIB-1 index (4–6%), and absent ATRX protein expression. DNA analysis showed no evidence of methylation of the MGMT gene promoter. The presence of prominent microvascular proliferation and areas of necrosis were consistent with an IDH-mutant glioblastoma (WHO Grade 4).

Methods: The patient refused standard of care (SOC) and steroid medication after initial diagnosis, but was knowledgeable and self-motivated enough to consume a low-carbohydrate ketogenic diet consisting mostly of saturated fats, minimal vegetables, and a variety of meats. The patient used the glucose ketone index calculator to maintain his Glucose Ketone Index (GKI) near 2.0 without body weight loss.

Results: The tumor continued to grow slowly without expected vasogenic edema until 2017, when the patient opted for surgical debulking. The enhancing area, centered in the inferior frontal gyrus, was surgically excised. The pathology specimen confirmed IDH1-mutant GBM. Following surgery, the patient continued with a self-administered ketogenic diet to maintain low GKI values, indicative of therapeutic ketosis. At the time of this report (May 2021), the patient remains alive with a good quality of life, except for occasional seizures. MRI continues to show slow interval progression of the tumor.

Conclusion: This is the first report of confirmed IDH1-mutant GBM treated with KMT and surgical debulking without chemo- or radiotherapy. The long-term survival of this patient, now at 80 months, could be due in part to a therapeutic metabolic synergy between KMT and the IDH1 mutation that simultaneously target the glycolysis and glutaminolysis pathways that are essential for GBM growth. Further studies are needed to determine if this non-toxic therapeutic strategy could be effective in providing long-term management for other GBM patients with or without IDH mutations.

The Potential Health Benefits of the Ketogenic Diet: A Narrative Review

Considering the lack of a comprehensive, multi-faceted overview of the ketogenic diet (KD) in relation to health issues, we compiled the evidence related to the use of the ketogenic diet in relation to its impact on the microbiome, the epigenome, diabetes, weight loss, cardiovascular health, and cancer. The KD diet could potentially increase genetic diversity of the microbiome and increase the ratio of Bacteroidetes to Firmicutes. The epigenome might be positively affected by the KD since it creates a signaling molecule known as β-hydroxybutyrate (BHB). KD has helped patients with diabetes reduce their HbA1c and reduce the need for insulin. There is evidence to suggest that a KD can help with weight loss, visceral adiposity, and appetite control. The evidence also suggests that eating a high-fat diet improves lipid profiles by lowering low-density lipoprotein (LDL), increasing high-density lipoprotein (HDL), and lowering triglycerides (TG). Due to the Warburg effect, the KD is used as an adjuvant treatment to starve cancer cells, making them more vulnerable to chemotherapy and radiation. The potential positive impacts of a KD on each of these areas warrant further analysis, improved studies, and well-designed randomized controlled trials to further illuminate the therapeutic possibilities provided by this dietary intervention.

Daily Lifestyle Modifications to Improve Quality of Life and Survival in Glioblastoma: A Review

Survival in glioblastoma remains poor despite advancements in standard-of-care treatment. Some patients wish to take a more active role in their cancer treatment by adopting daily lifestyle changes to improve their quality of life or overall survival. We review the available literature through PubMed and Google Scholar to identify laboratory animal studies, human studies, and ongoing clinical trials. We discuss which health habits patients adopt and which have the most promise in glioblastoma. While results of clinical trials available on these topics are limited, dietary restrictions, exercise, use of supplements and cannabis, and smoking cessation all show some benefit in the comprehensive treatment of glioblastoma. Marital status also has an impact on survival. Further clinical trials combining standard treatments with lifestyle modifications are necessary to quantify their survival advantages.

Wnt/β-catenin Antagonists: Exploring New Avenues to Trigger Old Drugs in Alleviating Glioblastoma Multiforme

BACKGROUND

Glioblastoma multiforme is one of the most heterogenous primary brain tumor with high mortality. Nevertheless, of the current therapeutic approaches, survival rate remains poor with 12 to 15 months following preliminary diagnosis, this warrants the need for effective treatment modality. Wnt/β-catenin pathway is presumably the most noteworthy pathway up-regulated in almost 80% GBM cases contributing to tumor-initiation, progression and survival. Therefore, therapeutic strategies targeting key components of Wnt/β-catenin cascade using established genotoxic agents like temozolomide and pharmacological inhibitors would be an effective approach to modulate Wnt/β-catenin pathway. Recently, drug repurposing by means of effective combination therapy has gained importance in various solid tumors including GBM, by targeting two or more proteins in a single pathway, thereby possessing the ability to overcome the hurdle implicated by chemo-resistance in GBM.

OBJECTIVE

In this context, by employing computational tools, an attempt has been carried out to speculate the novel combinations against Wnt/β-catenin signaling pathway.

METHODS

We have explored the binding interactions of three conventional drugs namely temozolomide, metformin, chloroquine along with three natural compounds viz., epigallocatechin gallate, naringenin and phloroglucinol on the major receptors of Wnt/β-catenin signaling.

RESULTS

It was noted that all the experimental compounds possessed profound interaction with the two major receptors of Wnt/β-catenin pathway.

CONCLUSION

To the best of our knowledge, this study is the first of its kind to characterize the combined interactions of the afore-mentioned drugs on Wnt/β-catenin signaling in silico and this will putatively open up new avenues for combination therapies in GBM treatment.

Possible Nutrition-Related Mechanisms of Metabolic Management in Cancer Treatment

Context: Somatic mutation theory has been considered as a potential cause for cancer. However, major inconsistencies with the gene theory have necessitated serious reconsideration of this assumption. According to these inconsistencies, cancer may be considered as a metabolic disorder. According to the mitochondrial metabolic theory, substrate-level phosphorylation has been suggested to be superior to oxidative phosphorylation in cancer cells. Cancer metabolic therapies such as ketogenic diets (KD) and limitation in glutamine and calorie can be beneficial and are in line with this theory. In this study, we have reviewed the potential effects of KD as well as glutamine and calorie restriction in various types/stages of cancer with a focus on possible mechanisms. Evidence Acquisition: A comprehensive electronic search of different databases was performed using “cancer”, “ketogenic diet”, and “metabolic” as the main keywords. A comprehensive electronic search of different databases was performed using “cancer”, “ketogenic diet”, and “metabolic” as the main keywords. Results: Emerging evidence has indicated that KD can affect tumor cells by reducing glucose availability and simultaneous elevation of ketone bodies as non-fermentable metabolic fuels. KD has been suggested to be more effective as a non-toxic therapeutic measure in combination with glutamine targeting agents, chloroquine for lysosomal targeting, hyperbaric oxygen therapy, and calorie restriction. Conclusions: This metabolic approach can be considered as a promising non-toxic strategy for cancer management.

Effects of caloric restriction on immunosurveillance, microbiota and cancer cell phenotype: Possible implications for cancer treatment

Fasting, caloric restriction and foods or compounds mimicking the biological effects of caloric restriction, known as caloric restriction mimetics, have been associated with a lower risk of age-related diseases, including cardiovascular diseases, cancer and cognitive decline, and a longer lifespan. Reduced calorie intake has been shown to stimulate cancer immunosurveillance, reducing the migration of immunosuppressive regulatory T cells towards the tumor bulk. Autophagy stimulation via reduction of lysine acetylation, increased sensitivity to chemo- and immunotherapy, along with a reduction of insulin-like growth factor 1 and reactive oxygen species have been described as some of the major effects triggered by caloric restriction. Fasting and caloric restriction have also been shown to beneficially influence gut microbiota composition, modify host metabolism, reduce total cholesterol and triglyceride levels, lower diastolic blood pressure and elevate morning cortisol level, with beneficial modulatory effects on cardiopulmonary fitness, body fat and weight, fatigue and weakness, and general quality of life. Moreover, caloric restriction may reduce the carcinogenic and metastatic potential of cancer stem cells, which are generally considered responsible of tumor formation and relapse. Here, we reviewed in vitro and in vivo studies describing the effects of fasting, caloric restriction and some caloric restriction mimetics on immunosurveillance, gut microbiota, metabolism, and cancer stem cell growth, highlighting the molecular and cellular mechanisms underlying these effects. Additionally, studies on caloric restriction interventions in cancer patients or cancer risk subjects are discussed. Considering the promising effects associated with caloric restriction and caloric restriction mimetics, we think that controlled-randomized large clinical trials are warranted to evaluate the inclusion of these non-pharmacological approaches in clinical practice.

Treatment of glioblastoma multiforme with "classic" 4:1 ketogenic diet total meal replacement

Introduction

Glioblastoma (GBM) has poor survival with standard treatment. Experimental data suggest potential for metabolic treatment with low carbohydrate ketogenic diet (KD). Few human studies of KD in GBM have been done, limited by difficulty and variability of the diet, compliance, and feasibility issues. We have developed a novel KD approach of total meal replacement (TMR) program using standardized recipes with ready-made meals. This pilot study evaluated feasibility, safety, tolerability, and efficacy of GBM treatment using TMR program with “classic” 4:1 KD.

Method

GBM patients were treated in an open-label study for 6 months with 4:1 [fat]:[protein + carbohydrate] ratio by weight, 10 g CH/day, 1600 kcal/day TMR. Patients were either newly diagnosed (group 1) and treated adjunctively to radiation and temozolomide or had recurrent GBM (group 2). Patients checked blood glucose and blood and urine ketone levels twice daily and had regular MRIs. Primary outcome measures included retention, treatment-emergent adverse events (TEAEs), and TEAE-related discontinuation. Secondary outcome measures were survival time from treatment initiation and time to MRI progression.

Results

Recruitment was slow, resulting in early termination of the study. Eight patients participated, 4 in group 1 and 4 in group 2. Five (62.5%) subjects completed the 6 months of treatment, 4/4 subjects in group 1 and 1/4 in group 2. Three subjects stopped KD early: 2 (25%) because of GBM progression and one (12.5%) because of diet restrictiveness. Four subjects, all group 1, continued KD on their own, three until shortly before death, for total of 26, 19.3, and 7 months, one ongoing. The diet was well tolerated. TEAEs, all mild and transient, included weight loss and hunger (n = 6) which resolved with caloric increase, nausea (n = 2), dizziness (n = 2), fatigue, and constipation (n = 1 each). No one discontinued KD because of TEAEs. Seven patients died. For these, mean (range) survival time from diet initiation was 20 months for group 1 (9.5–27) and 12.8 months for group 2 (6.3–19.9). Mean survival time from diagnosis was 21.8 months for group 1 (11–29.2) and 25.4 months for group 2 ( 13.9–38.7). One patient with recurrent GBM and progression on bevacizumab experienced a remarkable symptom reversal, tumor shrinkage, and edema resolution 6–8 weeks after KD initiation and survival for 20 months after starting KD.

Conclusion

Treatment of GBM patients with 4:1 KD using total meal replacement program with standardized recipes was well tolerated. The small sample size limits efficacy conclusions.

Trial registration

NCT01865162 registered 30 May 2013, and NCT02302235 registered 26 November 2014, https://clinicaltrials.gov/

Identification of a Metabolism-Related Risk Signature Associated With Clinical Prognosis in Glioblastoma Using Integrated Bioinformatic Analysis

Altered metabolism of glucose, lipid and glutamine is a prominent hallmark of cancer cells. Currently, cell heterogeneity is believed to be the main cause of poor prognosis of glioblastoma (GBM) and is closely related to relapse caused by therapy resistance. However, the comprehensive model of genes related to glucose-, lipid- and glutamine-metabolism associated with the prognosis of GBM remains unclear, and the metabolic heterogeneity of GBM still needs to be further explored. Based on the expression profiles of 1,395 metabolism-related genes in three datasets of TCGA/CGGA/GSE, consistent cluster analysis revealed that GBM had three different metabolic status and prognostic clusters. Combining univariate Cox regression analysis and LASSO-penalized Cox regression machine learning methods, we identified a 17-metabolism-related genes risk signature associated with GBM prognosis. Kaplan-Meier analysis found that obtained signature could differentiate the prognosis of high- and low-risk patients in three datasets. Moreover, the multivariate Cox regression analysis and receiver operating characteristic curves indicated that the signature was an independent prognostic factor for GBM and had a strong predictive power. The above results were further validated in the CGGA and GSE13041 datasets, and consistent results were obtained. Gene set enrichment analysis (GSEA) suggested glycolysis gluconeogenesis and oxidative phosphorylation were significantly enriched in high- and low-risk GBM. Lastly Connectivity Map screened 54 potential compounds specific to different subgroups of GBM patients. Our study identified a novel metabolism-related gene signature, in addition the existence of three different metabolic status and two opposite biological processes in GBM were recognized, which revealed the metabolic heterogeneity of GBM. Robust metabolic subtypes and powerful risk prognostic models contributed a new perspective to the metabolic exploration of GBM.

Perspective: Do Fasting, Caloric Restriction, and Diets Increase Sensitivity to Radiotherapy? A Literature Review

Caloric starvation, as well as various diets, has been proposed to increase the oxidative DNA damage induced by radiotherapy (RT). However, some diets could have dual effects, sometimes promoting cancer growth, whereas proposing caloric restriction may appear counterproductive during RT considering that the maintenance of weight is a major factor for the success of this therapy. A systematic review was performed via a PubMed search on RT and fasting, or caloric restriction, ketogenic diet (>75% of fat-derived energy intake), protein starvation, amino acid restriction, as well as the Warburg effect. Twenty-six eligible original articles (17 preclinical studies and 9 clinical noncontrolled studies on low-carbohydrate, high-fat diets popularized as ketogenic diets, representing a total of 77 patients) were included. Preclinical experiments suggest that a short period of fasting prior to radiation, and/or transient caloric restriction during treatment course, can increase tumor responsiveness. These regimens promote accumulation of oxidative lesions and insufficient repair, subsequently leading to cancer cell death. Due to their more flexible metabolism, healthy cells should be less sensitive, shifting their metabolism to support survival and repair. Interestingly, these regimens might stimulate an acute anticancer immune response, and may be of particular interest in tumors with high glucose uptake on positron emission tomography scan, a phenotype associated with poor survival and resistance to RT. Preclinical studies with ketogenic diets yielded more conflicting results, perhaps because cancer cells can sometimes metabolize fatty acids and/or ketone bodies. Randomized trials are awaited to specify the role of each strategy according to the clinical setting, although more stringent definitions of proposed diet, nutritional status, and consensual criteria for tumor response assessment are needed. In conclusion, dietary interventions during RT could be a simple and medically economical and inexpensive method that may deserve to be tested to improve efficiency of radiation.

Promising Effect of a New Ketogenic Diet Regimen in Patients with Advanced Cancer

A ketogenic diet is expected to be an effective support therapy for patients with cancer, but the degree and duration of carbohydrate restriction are unclear. We performed a case series study of a new ketogenic diet regimen in patients with different types of stage IV cancer. Carbohydrates were restricted to 10 g/day during week one, 20 g/day from week two for three months, and 30 g/day thereafter. A total of 55 patients participated in the study, and data from 37 patients administered the ketogenic diet for three months were analyzed. No severe adverse events associated with the diet were observed. Total ketone bodies increased significantly, and both fasting blood sugar and insulin levels were suppressed significantly for three months after completion of the study. Five patients showed a partial response on Positron emission tomography–computed tomography (PET-CT) at three months. Three and seven patients showed complete and partial responses, respectively at one year. Median survival was 32.2 (maximum: 80.1) months, and the three-year survival rate was 44.5%. After three months on the ketogenic diet, the serum Alb, BS, and CRP (ABC) score could be used to stratify the patients into groups with significantly different survival rates (p < 0.001, log-rank test). Our ketogenic diet regimen is considered to be a promising support therapy for patients with different types of advanced cancer.

Mitochondria in cancer

The rediscovery and reinterpretation of the Warburg effect in the year 2000 occulted for almost a decade the key functions exerted by mitochondria in cancer cells. Until recent times, the scientific community indeed focused on constitutive glycolysis as a hallmark of cancer cells, which it is not, largely ignoring the contribution of mitochondria to the malignancy of oxidative and glycolytic cancer cells, being Warburgian or merely adapted to hypoxia. In this review, we highlight that mitochondria are not only powerhouses in some cancer cells, but also dynamic regulators of life, death, proliferation, motion and stemness in other types of cancer cells. Similar to the cells that host them, mitochondria are capable to adapt to tumoral conditions, and probably to evolve to ‘oncogenic mitochondria' capable of transferring malignant capacities to recipient cells. In the wider quest of metabolic modulators of cancer, treatments have already been identified targeting mitochondria in cancer cells, but the field is still in infancy.

Consideration of Ketogenic Metabolic Therapy as a Complementary or Alternative Approach for Managing Breast Cancer

Breast cancer remains as a significant cause of morbidity and mortality in women. Ultrastructural and biochemical evidence from breast biopsy tissue and cancer cells shows mitochondrial abnormalities that are incompatible with energy production through oxidative phosphorylation (OxPhos). Consequently, breast cancer, like most cancers, will become more reliant on substrate level phosphorylation (fermentation) than on oxidative phosphorylation (OxPhos) for growth consistent with the mitochondrial metabolic theory of cancer. Glucose and glutamine are the prime fermentable fuels that underlie therapy resistance and drive breast cancer growth through substrate level phosphorylation (SLP) in both the cytoplasm (Warburg effect) and the mitochondria (Q-effect), respectively. Emerging evidence indicates that ketogenic metabolic therapy (KMT) can reduce glucose availability to tumor cells while simultaneously elevating ketone bodies, a non-fermentable metabolic fuel. It is suggested that KMT would be most effective when used together with glutamine targeting. Information is reviewed for suggesting how KMT could reduce systemic inflammation and target tumor cells without causing damage to normal cells. Implementation of KMT in the clinic could improve progression free and overall survival for patients with breast cancer.

Dissecting pharmacological effects of chloroquine in cancer treatment: interference with inflammatory signaling pathways

Chloroquines are 4-aminoquinoline-based drugs mainly used to treat malaria. At pharmacological concentrations, they have significant effects on tissue homeostasis, targeting diverse signaling pathways in mammalian cells. A key target pathway is autophagy, which regulates macromolecule turnover in the cell. In addition to affecting cellular metabolism and bioenergetic flow equilibrium, autophagy plays a pivotal role at the interface between inflammation and cancer progression. Chloroquines consequently have critical effects in tissue metabolic activity and importantly, in key functions of the immune system. In this article, we will review the work addressing the role of chloroquines in the homeostasis of mammalian tissue, and the potential strengths and weaknesses concerning their use in cancer therapy.

Ketogenic diet in the treatment of cancer - Where do we stand?

BACKGROUND

Cancer is one of the greatest public health challenges worldwide, and we still lack complementary approaches to significantly enhance the efficacy of standard anticancer therapies. The ketogenic diet, a high-fat, low-carbohydrate diet with adequate amounts of protein, appears to sensitize most cancers to standard treatment by exploiting the reprogramed metabolism of cancer cells, making the diet a promising candidate as an adjuvant cancer therapy.

SCOPE OF REVIEW

To critically evaluate available preclinical and clinical evidence regarding the ketogenic diet in the context of cancer therapy. Furthermore, we highlight important mechanisms that could explain the potential antitumor effects of the ketogenic diet.

MAJOR CONCLUSIONS

The ketogenic diet probably creates an unfavorable metabolic environment for cancer cells and thus can be regarded as a promising adjuvant as a patient-specific multifactorial therapy. The majority of preclinical and several clinical studies argue for the use of the ketogenic diet in combination with standard therapies based on its potential to enhance the antitumor effects of classic chemo- and radiotherapy, its overall good safety and tolerability and increase in quality of life. However, to further elucidate the mechanisms of the ketogenic diet as a therapy and evaluate its application in clinical practice, more molecular studies as well as uniformly controlled clinical trials are needed.

In vitro quantification: Long-term effect of glucose deprivation on various cancer cell lines

OBJECTIVE

Although metabolic treatment of highly glycolytic cancers and metastases is becoming an important research field, the effects of such treatments are not fully quantified yet. In this article we attempt to quantify the effect of long-term glucose deprivation (similar to ketogenic diets) on cancer cells using in vitro tests.

METHODS

Two tumorigenic cell lines were used, namely a metastatic breast and a cervical cancer cell line. The non-tumorigenic control cell line was an immortalized breast cell line. All the cell lines were stabilized at a typical average human blood glucose level of 6 mmol/L. The cell lines were then exposed to the therapeutic blood glucose level of 3 mmol/L for 90 d.

RESULTS

The tests indicated that glucose deprivation restricted the different cancer cell lines' growth more than that of non-tumorigenic cells. The different cell lines were also differentially affected, which suggests that long-term glucose deprivation will not be equally effective for different types of cancer. The highly glycolytic breast cancer cell line was most adversely affected, with cell growth decreasing to 30% after 26 d. Cell growth was stable at this level for up to 22 d. Furthermore, all of the other cancer cell lines were similarly affected.

CONCLUSIONS

This in vitro data could help to direct future human in vivo tests to find the most therapeutic time (cancer cells at their most vulnerable) for additional short-term adjuvant therapies. Partial recovery of proliferation occurred after 90 d. Therefore, as expected, the results also indicated that without an adjuvant treatment, full extinction cannot be reached with the proposed long-term metabolic treatment. The need for more clinical data on long-term glucose deprivation treatments for cancer is well described in the literature. This paper attempts to add to the available pool of knowledge.

Ketogenic diets in medical oncology: a systematic review with focus on clinical outcomes

Preclinical data provide evidence for synergism between ketogenic diets (KDs) and other oncological therapies. The aim of this systematic review was to summarize data from clinical studies that have tested KDs along with other treatments used within medical oncology. The PubMed database was searched using the key words "ketogenic" AND ("cancer" OR "glioblastoma"). A secondary search was conducted by screening the reference lists of relevant articles on this topic. Relevant studies for this review were defined as studies in which KDs were used complementary to surgery, radio-, chemo-, or targeted therapy and at least one of the following four outcomes were reported: (i) Overall survival (OS); (ii) progression-free survival (PFS); (iii) local control rate; (iv) body composition changes. Twelve papers reporting on 13 clinical studies were identified. Nine studies were prospective and six had a control group, but only two were randomized. KD prescription varied widely between studies and was described only rudimentarily in most papers. Adverse events attributed to the diet were rare and only minor (grade 1-2) except for one possibly diet-related grade 4 event. Studies reporting body composition changes found beneficial effects of KDs in both overweight and frail patient populations. Beneficial effects of KDs on OS and/or PFS were found in four studies including one randomized controlled trial. Studies in high-grade glioma patients were not sufficiently powered to prove efficacy. Evidence for beneficial effects of KDs during cancer therapy is accumulating, but more high-quality studies are needed to assess the overall strength of evidence.

Analysis of Glioblastoma Multiforme Tumor Metabolites Using Multivoxel Magnetic Resonance Spectroscopy

BACKGROUND

Glioblastoma Multiforme (GBM) is the most common and deadly type of primary brain tumor in adults. Magnetic Resonance Spectroscopy (MRS) is a noninvasive imaging technique used to study metabolic changes in the brain tumors. Some metabolites such as Phosphocholine, Creatine, NAA/Cr, and Pcho/Cr have been proven to show a diagnostic role in GBM. The present study was conducted to analyze important metabolites using MRS multivoxel in GBM tumor.

METHODS

In this study, information was collected from 8 individuals diagnosed with GBM using Siemens multivoxel MRS with a magnetic field strength of 3 T. Data were obtained by Point-Resolved Spectroscopy (PRESS) protocol with TE=135 ms and TR=1570 ms. NAA, Pcho, Cr, Ala, Gln, Gly, Glu, Lac, NAAG, and Tau metabolites were extracted and evaluated statistically.

RESULTS

Given total number of normal voxels and total number of all voxels, levels of Cr, Glu, NAA, NAAG, and Gly/Tau ratio in healthy voxels were significantly higher than tumoral voxels (p=0.005, p=0.03, p<0.001, p<0.001 and p=0.041, respectively). In contrast, levels of Gly, Gln, Tau, Lac/Cr, Pcho/Cr, Pcho/NAA, Lac/NAA, and Gln/Glu ratios in tumoral voxels were significantly more than healthy voxels (p=0.001, p= 0.037, p<0.001, p=0.010, p<0.001, p<0.001, and p=0.024, respectively). However, levels of Lac and Pcho had no significant difference in the two types of voxels.

CONCLUSION

In summary, compared to patients with glioblastoma with ¹H-MRS, the Pcho/Cr and Pcho/NAA ratios, and NAAG are the most important parameters to differentiate between tumoral and normal voxels.

Fasting as a Therapy in Neurological Disease

Fasting is deeply entrenched in evolution, yet its potential applications to today’s most common, disabling neurological diseases remain relatively unexplored. Fasting induces an altered metabolic state that optimizes neuron bioenergetics, plasticity, and resilience in a way that may counteract a broad array of neurological disorders. In both animals and humans, fasting prevents and treats the metabolic syndrome, a major risk factor for many neurological diseases. In animals, fasting probably prevents the formation of tumors, possibly treats established tumors, and improves tumor responses to chemotherapy. In human cancers, including cancers that involve the brain, fasting ameliorates chemotherapy-related adverse effects and may protect normal cells from chemotherapy. Fasting improves cognition, stalls age-related cognitive decline, usually slows neurodegeneration, reduces brain damage and enhances functional recovery after stroke, and mitigates the pathological and clinical features of epilepsy and multiple sclerosis in animal models. Primarily due to a lack of research, the evidence supporting fasting as a treatment in human neurological disorders, including neurodegeneration, stroke, epilepsy, and multiple sclerosis, is indirect or non-existent. Given the strength of the animal evidence, many exciting discoveries may lie ahead, awaiting future investigations into the viability of fasting as a therapy in neurological disease.

Effects of Radiation Therapy on Neural Stem Cells

Brain and nervous system cancers in children represent the second most common neoplasia after leukemia. Radiotherapy plays a significant role in cancer treatment; however, the use of such therapy is not without devastating side effects. The impact of radiation-induced damage to the brain is multifactorial, but the damage to neural stem cell populations seems to play a key role. The brain contains pools of regenerative neural stem cells that reside in specialized neurogenic niches and can generate new neurons. In this review, we describe the advances in radiotherapy techniques that protect neural stem cell compartments, and subsequently limit and prevent the occurrence and development of side effects. We also summarize the current knowledge about neural stem cells and the molecular mechanisms underlying changes in neural stem cell niches after brain radiotherapy. Strategies used to minimize radiation-related damages, as well as new challenges in the treatment of brain tumors are also discussed.

Ketogenic dietary therapies for epilepsy and beyond

PURPOSE OF REVIEW

The ketogenic diet, a high-fat, low-carbohydrate therapy, has become an established treatment for pediatric epilepsy since 1921. There has recently been an increase in important studies on the ketogenic diet, and this review will highlight the most recent in order to provide a synthesis of where this field stands today.

RECENT FINDINGS

Clinical studies continue to support the use of ketogenic diets in epilepsy, with more recent trials supporting its use in adults. Clinical recommendations published in 2018 based on a decade of practice and research, guide implementation and management of the ketogenic diet in epilepsy. One of the most rapidly growing 'indications' includes the role of ketogenic diets in status epilepticus. An exciting new potential mechanism for how the ketogenic diet exerts its antiseizure effects is through changing the composition of the gut microbiome. Lastly, ketogenic diets are being applied to a range of neurological conditions from autism to Alzheimer's disease.

SUMMARY

The ketogenic diet is a versatile therapy, with growing clinical evidence and guidelines, widely used for the treatment of epilepsy. New indications include status epilepticus and neurological conditions other than epilepsy.

Therapeutic benefit of combining calorie-restricted ketogenic diet and glutamine targeting in late-stage experimental glioblastoma

Glioblastoma (GBM) is an aggressive primary human brain tumour that has resisted effective therapy for decades. Although glucose and glutamine are the major fuels that drive GBM growth and invasion, few studies have targeted these fuels for therapeutic management. The glutamine antagonist, 6-diazo-5-oxo-L-norleucine (DON), was administered together with a calorically restricted ketogenic diet (KD-R) to treat late-stage orthotopic growth in two syngeneic GBM mouse models: VM-M3 and CT-2A. DON targets glutaminolysis, while the KD-R reduces glucose and, simultaneously, elevates neuroprotective and non-fermentable ketone bodies. The diet/drug therapeutic strategy killed tumour cells while reversing disease symptoms, and improving overall mouse survival. The therapeutic strategy also reduces edema, hemorrhage, and inflammation. Moreover, the KD-R diet facilitated DON delivery to the brain and allowed a lower dosage to achieve therapeutic effect. The findings support the importance of glucose and glutamine in driving GBM growth and provide a therapeutic strategy for non-toxic metabolic management.

Provocative Question: Should Ketogenic Metabolic Therapy Become the Standard of Care for Glioblastoma?

No major advances have been made in improving overall survival for glioblastoma (GBM) in almost 100 years. The current standard of care (SOC) for GBM involves immediate surgical resection followed by radiotherapy with concomitant temozolomide chemotherapy. Corticosteroid (dexamethasone) is often prescribed to GBM patients to reduce tumor edema and inflammation. The SOC disrupts the glutamate-glutamine cycle thus increasing availability of glucose and glutamine in the tumor microenvironment. Glucose and glutamine are the prime fermentable fuels that underlie therapy resistance and drive GBM growth through substrate level phosphorylation in the cytoplasm and the mitochondria, respectively. Emerging evidence indicates that ketogenic metabolic therapy (KMT) can reduce glucose availability while elevating ketone bodies that are neuroprotective and non-fermentable. Information is presented from preclinical and case report studies showing how KMT could target tumor cells without causing neurochemical damage thus improving progression free and overall survival for patients with GBM.