Targeting cancer with metabolic therapy and hyperbaric oxygen

Abstract

A method of treating cancer using ketogenic diet, while concurrently subjecting the patient to a hyperbaric, oxygen-enriched environment. Optionally, the hyperbaric, oxygen-enriched environment is 100% oxygen at 2.5 ATA absolute. The treatment may further include administering at least 10% ketone supplementation, such as acetoacetate, adenosine monophosphate kinase, 1,3-butanediol, or ketone ester, to the patient.

Claims

1. A method of reducing metastasis in cancer, comprising: administering to an animal with a metastatic cancer a therapeutically effective amount of acetoacetate, 1,3-butanediol acetoacetate monoester, 1,3-butanediol acetoacetate diester, R,S-1,3-butanediol-diacetoacetate ester, R-1,3-butanediol diacetoacetate ester, or a combination thereof.

2. The method of claim 1, further comprising subjecting the animal to a hyperbaric, oxygen-enriched environment.

3. The method of claim 2, wherein the hyperbaric, oxygen-enriched environment is 100% oxygen.

4. The method of claim 3, wherein the hyperbaric, oxygen-enriched environment is at 2.5 ATA absolute.

5. The method of claim 3, wherein the animal is subjected to the hyperbaric, oxygen-enriched environment for 90 minutes three times a week.

6. The method of claim 1, wherein the acetoacetate, 1,3-butanediol acetoacetate monoester, 1,3-butanediol acetoacetate diester, R,S-1,3-butanediol-diacetoacetate ester, R-1,3-butanediol diacetoacetate ester, or a combination thereof is administered at 10 g/kg of body weight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:

(2) FIG. 1 is an illustration of energy metabolism of cancer cell compared to a normal cell.

(3) FIG. 2 is an illustration showing linking hypoxia to cancer progression. Image from Vaupel, P. et. al (Vaupel & Harrison (2004) Tumor hypoxia: causative factors, compensatory mechanisms, and cellular response. The oncologist 9 Suppl 5: 4-9).

(4) FIG. 3 is a Kaplan-Meier survival plot of study groups. KD-USF fed mice exhibited significantly longer mean survival times compared to control animals (p<0.05, Kaplan-Meier survival curve analysis).

(5) FIG. 4 are images showing metastatic spread represented by tumor bioluminescence. KD-fed mice exhibited noticeably less tumor bioluminescence than controls on day 21 post-inoculation.

(6) FIG. 5 is a graph showing bioluminescence shown as a function of time demonstrates the slower rate of tumor growth in KD-fed mice compared to controls.

(7) FIG. 6 is a graph showing animals in the treatment groups showed slower tumor growth than controls. Total body bioluminescence was measured weekly as a measure of tumor size; error bars represent ±SEM.

(8) FIG. 7 is a Kaplan-Meier survival plot graph of study groups showing supplemental ketone administration increases survival time in mice with systemic metastatic cancer. All treatment groups exhibited a significantly different survival from control animals by the Logrank Survival Test (p=0.05) and significant increases in mean survival time means compared to control animals by two-tailed student's t-test (p<0.05).

(9) FIG. 8 are images showing ketone supplementation increases survival time and slows tumor growth in mice with systemic metastatic cancer. Metastatic spread represented by tumor bioluminescence. Ketone supplement-fed mice exhibited noticeably less tumor bioluminescence than controls on day 21 post-inoculation.

(10) FIG. 9 is a graph showing animal weight. The graph bars indicate average percent of initial body weight for animals at weeks 2, 4, and 6. Error bars represent ±SEM.

(11) FIG. 10 is a graph showing blood glucose levels in animals. Mice receiving supplemental ketone ester (SDKE and KDKE) showed significantly lower glucose than controls on day 7 (p<0.01). Animals in the SDKE, KDKE, and KDBD groups had significantly lower blood glucose levels than controls on day 14 (p<0.01).

(12) FIG. 11 is a graph showing β-hydroxybutyrate levels in animals. KDKE and KDBD groups had significantly higher blood ketones than controls on both day 7 and day 14 (p<0.05).

(13) FIG. 12 are images showing ketogenic diet and hyperbaric oxygen therapy work synergistically to slow cancer progression. Metastatic spread and tumor growth rate was dramatically decreased.

(14) FIG. 13 is a graph showing ketogenic diet and hyperbaric oxygen therapy work synergistically to slow cancer progression. Mice receiving combined therapy demonstrated significantly longer survival curves and increased mean survival time compared to controls (p<0.05, Kaplan-Meier survival curve analysis). The effect was supra-additive compared to either therapy alone, indicating a synergistic mechanism of action.

(15) FIG. 14 is a graph showing animals in the treatment groups showed slower tumor growth than controls. Total body bioluminescence was measured weekly as a measure of tumor size; error bars represent ±SEM.

(16) FIGS. 15(A) and (B) are graphs showing ketogenic diet and hyperbaric oxygen therapy work synergistically to slow cancer progression. Mice receiving combined therapy demonstrated dramatically decreased metastatic spread and tumor growth rate. The effect was supra-additive compared to either therapy alone, indicating a synergistic mechanism of action.

(17) FIG. 16 is a graph showing blood and glucose levels in animals. KD mice showed significantly lower glucose than controls on day 7 (p<0.05). Animals in the KD-Solace, KD-USF, and KD+HBO.sub.2T groups had significantly lower blood glucose levels than controls on day 14 (p<0.05).

(18) FIG. 17 is a graph showing animal weight. The graph bars indicate average percent of initial body weight for animals at weeks 2, 4, and 6. Error bars represent ±SEM.

(19) FIG. 18 is a graph showing β-hydroxybutyrate levels in animals. KD+HBO.sub.2T mice had significantly higher blood ketones than controls on day 7 (p<0.001). KD-Solace, KD-USF, and KD+HBO.sub.2T mice exhibited a trend of elevated ketones on day 14, but were not significantly different from controls.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(20) ACA, acetoacetate; AFM, atomic force microscopy; AMPK, adenosine monophosphate kinase ATA, atmospheres absolute pressure (sea level=1 atmosphere, 33 feet of seawater, 760 mmHg); βHB, Beta-hydroxybutyrate; BD, 1,3-butanediol; CO.sub.2, carbon dioxide; CR, calorie restriction; DER, dietary energy restriction; DHE, dihydroethidium; EH-1, Ethidium Homodimer-1; FI, fluorescence intensity; GBM, glioblastoma multiforme; HAFM, hyperbaric atomic force microscopy (AFM inside hyperbaric chamber); H.sub.2O.sub.2, hydrogen peroxide; HBO.sub.2, hyperbaric oxygen; HBO.sub.2T, hyperbaric oxygen therapy; HIF-1, hypoxia inducible factor-1; IGF-1, insulin-like growth factor 1; KD, ketogenic diet; KE, ketone ester; OXPHOS, oxidative phosphorylation; mTOR, mammalian target of rapamycin; MLP, membrane lipid peroxidation; PI3K, phosphoinositide-3 kinase; PO.sub.2, oxygen partial pressure; PTEN, phosphatase and tensin homolog; ROS, reactive oxygen species; .O.sub.2.sup.−, superoxide anion; R.sub.a, average roughness; t, time; SKA, supplemental ketone administration; SLP, substrate level phosphorylation; VEGF, vascular endothelial growth factor.

(21) As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a polypeptide” includes a mixture of two or more polypeptides and the like.

(22) As used herein, “about” means approximately or nearly and in the context of a numerical value or range set forth means±15% of the numerical.

(23) As used herein “animal” means a multicellular, eukaryotic organism classified in the kingdom Animalia or Metazoa. The term includes, but is not limited to, mammals. Non-limiting examples include rodents, aquatic mammals, domestic animals such as dogs and cats, farm animals such as sheep, pigs, cows and horses, and humans. Wherein the terms “animal” or “mammal” or their plurals are used, it is contemplated that it also applies to any animals.

(24) As used herein, the term “cancer” or “cancerous” refer to or describe the physiological condition in mammals that is typically characterized by unregulated cell growth, i.e., proliferative disorders. Examples of such proliferative disorders include cancers such as carcinoma, lymphoma, blastoma, sarcoma, and leukemia, as well as other cancers disclosed herein. More particular examples of such cancers include breast cancer, prostate cancer, colon cancer, squamous cell cancer, small-cell lung cancer, non-small cell lung cancer, gastrointestinal cancer, pancreatic cancer, cervical cancer, ovarian cancer, liver cancer, e.g., hepatic carcinoma, bladder cancer, colorectal cancer, endometrial carcinoma, kidney cancer, and thyroid cancer.

(25) As used herein “glycolytic cancer” means a cancer cell which utilizes the glycolytic pathway as a sole means of energy production. The glycolytic pathway refers to overall process of the enzymatic breakdown of a carbohydrate with a resultant production of energy using the Embden-Meyerhof pathway sequence: glucose; glucose-6-phosphate; fructose-6-phosphate; fructose-1,6-diphosphate; dihydroxyacetone-phosphate; glyceraldehyde-3-phosphate; 1,3-diphosphoglycerate; 3-phosphoglycerate; 2-phosphoglycerate; phosphoenolpyruvate (PEP); pyruvate; acetaldehyde; and acetate. The TAC intermediates are succinate, oxalacetate, malate, fumarate, 2-keto-glutarate, isocitrate, and citrate.

(26) As used herein the term “patient” is understood to include an animal, especially a mammal, and more especially a human that is receiving or intended to receive treatment.

(27) As used herein, the term “effective amount” refers to the amount of a compound which is sufficient to reduce or ameliorate the progression and or severity of cancer or one or more symptoms thereof, prevent the development, recurrence or onset of pancreatic cancer or one or more symptoms thereof, prevent the advancement of pancreatic cancer or one or more symptoms thereof.

(28) As used herein, the term “therapeutically effective amount” refers to that amount of a therapy (e.g., a chemotherapeutic agent) sufficient to result in the amelioration of pancreatic cancer or one or more symptoms thereof, prevent advancement of bladder cancer cause regression of bladder cancer, or to enhance or improve the therapeutic effect(s) of another therapy (e.g., chemotherapeutic agent).

Example 1

(29) To determine the anti-cancer effects of KD metabolic therapy on cancer, survival time, rate of tumor growth, body weight, blood glucose, and blood ketones were measured in mice with VM-M3 metastatic cancer treated with KD,

(30) VM-M3/Fluc cells (T. Seyfried; Boston College) were obtained from a spontaneous tumor in a VM/Dk inbred mouse and adapted to cell culture (Huysentruyt et al., Metastatic cancer cells with macrophage properties: evidence from a new murine tumor model. Intl J Can. 2008, 123(1):73-84). The VM-M3 cells were identified from a spontaneous tumor in VM/dk inbred strain, and exhibit highly metastatic properties upon subcutaneous implantation, with rapidly metastasis throughout the model organism. VM-M3/Fluc cells are transfected with the firefly luciferase gene which produces a bioluminescent product in the presence of the enzymatic substrate luciferin (Shelton, et al. (2010) A novel pre-clinical in vivo mouse model for malignant brain tumor growth and invasion. Journal of neuro-oncology 99: 165-176). Bioluminescence can be detected and measured with the Xenogen IVIS Lumina System (Caliper LS). Intensity of bioluminescent signaling (photon count) is directly correlated to the number of luciferase-tagged cells within the animal (Kim, et al. (2010) Non-invasive detection of a small number of bioluminescent cancer cells in vivo. PloS one 5: e9364; Lim, et al. (2009) In vivo bioluminescent imaging of mammary tumors using IVIS spectrum. Journal of visualized experiments: JoVE) and is a well-accepted method of measuring tumor size in animals with luciferase-expressing tumors (Lyons (2005) Advances in imaging mouse tumour models in vivo. The Journal of pathology 205: 194-205; Close, et al. (2011) In vivo bioluminescent imaging (BLI): noninvasive visualization and interrogation of biological processes in living animals. Sensors (Basel, Switzerland) 11: 180-206). Mice received an i.p. injection of 50 mg/kg D-Luciferin 15 minutes prior to in vivo imaging. Bioluminescent signal was recorded using a 1 second exposure time on the IVIS Lumina cooled CCD camera. Progression of the metastatic cancer was measured by tracking the bioluminescent signal of the whole animal over time. Tumor bioluminescence will be measured once weekly for the duration of the study.

(31) Adult male mice (2-4 months of age) were separated into treatment groups, as provided in Table 1. On day 0 of the study, 1 million VM-M3/Fluc cells in 300 μL PBS were subcutaneously implanted into the abdomen of male, 10-18 week old VM/Dk mice using a 27 g needle. With the VM-M3 model, an adipose tumor quickly appeared following inoculation and rapidly metastasized to most major organs, including brain, lungs, liver, spleen, kidneys, and bone marrow (Huysentruyt, et al. (2008) Metastatic cancer cells with macrophage properties: evidence from a new murine tumor model. International journal of cancer Journal international du cancer 123: 73-84). On the day of tumor inoculation, mice were randomly assigned to one of five study groups: Control, KD-Solace, KD-USF, KD-USF, standard diet with 1,3-Butanediol (SD+BD) standard diet with ketone ester (SD+KE), KD-Solace with 1,3-Butanediol (KD+BD), or KD-Solace with ketone ester (KD+KE).

(32) TABLE-US-00001 TABLE 1 mouse feed groups for treatment Treatment group Treatments (food and pressure treatment) Control Standard diet fed ad libitum; ambient pressure KD-Solace Commercially available (Ketovolve, Solace Nutrition) ketogenic food fed ad libitum; ambient pressure KD-USF Teklad Custom Research Ketogenic diet designed by researchers (Harlan Laboratories) fed ad libitum; ambient pressure SD + BD Standard diet fed ad libitum + 1,3-Butanediol SD + KE Standard diet fed ad libitum + ketone ester KD + BD KD-Solace fed ad libitum + 1,3-Butanediol KD + KE KD-Solace food fed ad libitum + ketone ester

(33) Control mice were fed standard rodent chow (2018 Teklad Global 18% Protein Rodent Diet, Harlan Laboratories) fed ad libitum. Mice on a diet therapy received their respective diet fed ad libitum in lieu of standard rodent chow. Mice in the KD-Solace treatment group received KD-Solace (Solace Nutrition) ketogenic diet food, mixed 1:1 with H.sub.2O to form a paste. Mice in the KD-USF treatment group received a Teklad Custom Research Diet (Harlan Laboratories) designed by the researchers. The macronutrient information of the diets used in this study is provided in Table 2. The macronutrient ratio of the custom designed KD-USF diet is similar to ketogenic diets with very low carbohydrate (VLC), containing a high percentage of MCT oil (30-40%) and high protein (22%). The KD-USF diet is notably more palatable to the mice. Diets will be continuously replaced to maintain freshness and allow mice to feed ad libitum.

(34) TABLE-US-00002 TABLE 2 Macronutrient information for SD, KD-Solace, and KD-USFUSF. Macronutrient Standard Ketovolve Custom Information Diet (SD) KD-Solace KD-USF % Cal from Fat 6.2 89.2 77.1 % Cal from 18.6 8.7 22.4 Protein % Cal from 75.2 2.1 0.5 Carbohydrate Caloric Density 3.1 Kcal/g 7.12 Kcal/g 4.7 Kcal/g

(35) Animal survival was analyzed with the Kaplan-Meier and Logrank Tests for survival distribution. Mean survival and cell viability were analyzed by two-tailed student's t-tests. KD administration increased mean survival, seen in FIG. 3 and Table 3, by approximately 15 days. Both ketone diets also increased mean survival time compared to control animals, as seen in Table 3 (Two-tailed student's t-test; *p<0.05). Control (SD) mice lived an average of 33.7 days while KD-Solace treated mice had a statistically significant mean survival time of 48.9 days, increasing survival time by 45.1% (p>0.05; Two-tailed student's t-test). KD-USF treatment increased mean survival time by approximately 12 days (33.8%) compared to controls, as seen in Table 3.

(36) TABLE-US-00003 TABLE 3 The KD increases survival time and slows tumor growth in mice with systemic metastatic cancer. KD-USF fed mice exhibited significantly longer mean survival times compared to control animals (p < 0.05, student's t-test). Cohort Size Mean Survival Increase in Treatment (N) (days) Survival Time Control (SD) 11 33.7 — KD-Solace 8 48.9 45.1% KD-USF 7 45.1 33.8%

(37) Tumor progression was measured using bioluminescence on the Xenogen IVIS Lumina cooled CCD camera (Caliper LS, Hopkinton, Mass.). Bioluminescent signal of the luciferase-tagged cancer was acquired with the Living Image® software (Caliper LS). Mice received an i.p. injection of 50 mg/kg D-Luciferin (Caliper LS) 15 minutes prior to imaging. Bioluminescent signal was obtained using the IVIS Lumina cooled CCD camera system with a 1 sec exposure time. Whole animal bioluminescent signal was measured in photons/sec once a week as an indicator of metastatic tumor size and spread. Tumor progression was measured 21 days after tumor cell inoculation. As seen in FIG. 4, VM cells spread naturally in immunocompetent host mice. KD treatment, both KD-Solace and KD-USF, drastically reduced tumor progression, with KD-USF treatment also showing profound effect.

(38) Animals receiving the KD demonstrated a notable trend of slower tumor growth over time, with both KD-Solace and KD-USF treatments having similar growth rates as seen in FIG. 5. This trend reflected the increase in survival time seen in these animals.

Example 2

(39) The anti-cancer effects of R,S-1,3-butanediol diacetoacetate ester (KE) and 1,3-butanediol (BD) as sources of supplemental ketones for metabolic therapy were determined for survival time, rate of tumor growth, body weight, blood glucose, and blood ketones.

(40) Many cancers are unable to effectively utilize ketone bodies for energy (Maurer, et al. (2011) Differential utilization of ketone bodies by neurons and glioma cell lines: a rationale for ketogenic diet as experimental glioma therapy. BMC Cancer. 2011 Jul. 26; 11:315; Tisdale & Brennan (1983) Loss of acetoacetate coenzyme A transferase activity in tumours of peripheral tissues. British journal of cancer 47: 293-297; Magee, et al. (1979) The inhibition of malignant cell growth by ketone bodies. The Australian journal of experimental biology and medical science 57: 529-539). Furthermore, evidence suggests that ketones themselves possess inherent anti-cancer properties as βHB administration inhibits cancer cell proliferation and viability in vitro (Sawai, et al. (2004) Growth-inhibitory effects of the ketone body, monoacetoacetin, on human gastric cancer cells with succinyl-CoA: 3-oxoacid CoA-transferase (SCOT) deficiency. Anticancer research 24: 2213-2217; Magee, et al. (1979) The inhibition of malignant cell growth by ketone bodies. The Australian journal of experimental biology and medical science 57: 529-539). KDs are low carbohydrate, high fat diets that induce a modest elevation in blood ketone levels. R,S-1,3-butanediol-diacetoacetate ester (KE) is a non-ionized precursor to ketone bodies resulting in rapid elevation in ACA, and sustained elevation in βHB. 1,3-butanediol (BD) is a non-toxic food additive and hypoglycemic agent that is metabolized by liver to produce β-hydroxybutyrate. Both are potential food sources of supplemental ketone bodies which significantly elevate blood ketone concentrations regardless of diet (Desrochers, et al. (1995) Metabolism of (R,S)-1,3-butanediol acetoacetate esters, potential parenteral and enteral nutrients in conscious pigs. The American journal of physiology 268: E660-667; Kies, et al. (1973) Utilization of 1,3-butanediol and nonspecific nitrogen in human adults. The Journal of nutrition 103: 1155-1163; Puchowicz, et al. (2000) Dog model of therapeutic ketosis induced by oral administration of R,S-1,3-butanediol diacetoacetate. The Journal of nutritional biochemistry 11: 281-287; Brunengraber (1997) Potential of ketone body esters for parenteral and oral nutrition. Nutrition 13: 233-235; Tobin, et al. (1975) Nutritional and metabolic studies in humans with 1,3-butanediol. Federation proceedings 34: 2171-2176). To investigate the anti-cancer potential of ketones in vivo, the effects of supplemental ketone administration were tested alone and in combination with the KD on the VM-M3 mouse model of metastatic cancer.

(41) Adult male mice (2-4 months of age) were separated into treatment groups, as provided in Table 4 and injected with 1 million VM-M3/Fluc cells into the abdomen of male, 10-18 week old VM/Dk mice as described in Example 1. On the day of tumor inoculation, mice were randomly assigned to one of the five study groups.

(42) TABLE-US-00004 TABLE 4 mouse feed groups for treatment Treatment group Treatments (food and pressure treatment) SD (Control) Standard diet fed ad libitum SDKE Standard diet + 20% KE fed ad libitum SDBD Standard diet + 20% BD fed ad libitum KDKE KD-USF ketogenic diet food + 10% KE fed ad libitum KDBD KD-Solace ketogenic diet food + 20% BD fed ad libitum

(43) Two sources of supplemental ketones were used in this study: the R,S-1,3-butanediol-diacetoacetate ester (Ketone Ester, KE) and 1,3-butanediol (BD). The KE was synthesized (Savind Inc., Seymour Ill.) as previously described (D'Agostino et al., Therapeutic ketosis with ketone ester delays central nervous system oxygen toxicity seizures in rats. Am J Physiol Regul Integr Comp Physiol 2013, 304(10):R829-836) by transesterification of t-butylacetoacetate with R,S-1,3-butanediol (Savind Inc) and is a non-ionized, sodium-free, pH-neutral precursor of acetoacetate (ACA). The KE consists of two ACA molecules esterified to one molecule of 1,3-butanediol, an organic alcohol commonly used as a solvent in food flavoring agents. When ingested, gastric esterases rapidly cleave the KE to release two ACA molecules which are absorbed into circulation, rapidly elevating blood ketone concentration (Desrochers, et al. (1995) Metabolism of (R,S)-1,3-butanediol acetoacetate esters, potential parenteral and enteral nutrients in conscious pigs. The American journal of physiology 268: E660-667). The 1,3-butanediol molecule is absorbed and metabolized by the liver to produce βHB, providing a more sustained elevation of blood ketones. Administration of dietary BD is the second supplemental ketone source we will test, and it works to elevate ketone levels as previously described.

(44) Control mice received standard rodent chow fed ad libitum. Mice receiving ketone supplementation diet therapy was administered their respective diet fed ad libitum in lieu of standard rodent chow. Saccharin was added to increase palatability and does not have a measurable effect on metabolism. Supplemental ketones may be unpalatable to the mice causing the mice to self-calorie restrict (Kashiwaya, et al. (2010) A ketone ester diet increases brain malonyl-CoA and Uncoupling proteins 4 and 5 while decreasing food intake in the normal Wistar Rat. The Journal of biological chemistry 285: 25950-25956). As previously described, DER is known to inhibit cancer progression in vivo. However, testing showed calorie restriction did not have a significant effect on cancer progression (data not shown).

(45) SDKE mice received standard rodent chow mixed at 20% KE and 1% saccharin by volume. SDBD mice received standard rodent chow mixed at 20% BD and 0.1 to 1% saccharin by volume. KDKE mice received KD-USF ketogenic diet food mixed at 20% KE and 1% saccharin by volume. Mice in the KDBD treatment group received KD-Solace ketogenic diet food mixed at 20% BD, 29% H.sub.2O (to form a solid paste) and 0.1 to 1% saccharin by volume. See Table 5 for macronutrient information of diets and ketone supplements. Initial studies indicated that KD-Solace mixed with KE was severely unpalatable to the mice, so KD-USF mixed at 10% KE will be used for the KDKE group, since the KE was unpalatable to mice and was not consumed at 20% or when mixed with KD-Solace. Diets were continuously replaced to maintain freshness and allow mice to feed ad libitum.

(46) TABLE-US-00005 TABLE 5 Macronutrient information for SD, KD-Solace, KD-USF, BD, and KE. Standard Ketone Macronutrient Diet Ketovolve Custom 1,3-BD Ester Information (SD) KD-Solace KD-USF (BD) (KE) % Cal from Fat 6.2 89.2 77.1 N/A N/A % Cal from 18.6 8.7 22.4 N/A N/A Protein % Cal from 75.2 2.1 0.5 N/A N/A Carbohydrate Caloric Density 3.1 7.12 4.7 6.0 5.58 Kcal/g Kcal/g Kcal/g Kcal/g Kcal/g

(47) Blood was collected from the study animals every 7 days. Blood glucose and βHB concentrations were measured using a commercially available Glucose and Ketone (βHB) Monitoring System (Nova Biomedical and Abbott Laboratories). Mice were weighed twice weekly for the duration of the study using the AWS-1Kg Portable Digital Scale (AWS). Blood and weight measurements were taken at the same time of day each week to control for normal fluctuations in feeding or circadian metabolic changes. Studies will focus on health and behavior of the animals on a daily basis. Survival time was measured as the time in days from cancer cell inoculation to presentation of defined criteria (diminished response to stimuli, loss of grooming or feeding behavior, lethargy, severe ascites, or failure to thrive). At that time, mice were humanely euthanized by CO.sub.2 asphyxiation and survival time noted.

(48) Supplemental ketone administration was expected to increase survival time, slow tumor growth rate, decrease blood glucose, and elevate blood ketones in VM-M3 mice with metastatic cancer compared to control animals. Since the KE supplies more ketones to the tissues than BD, and ketones inhibit cancer cell proliferation in vitro (Sawai, et al. (2004) Growth-inhibitory effects of the ketone body, monoacetoacetin, on human gastric cancer cells with succinyl-CoA: 3-oxoacid CoA-transferase (SCOT) deficiency. Anticancer research 24: 2213-2217; Magee, et al. (1979) The inhibition of malignant cell growth by ketone bodies. The Australian journal of experimental biology and medical science 57: 529-539), it was expected that the anti-cancer effects of the supplemental ketone administration would be greater in KE-fed mice. Further, since carbohydrate restriction decreases blood glucose which cancer cells rely on for energy, combining KE or BD with a ketogenic diet was expected to be more effective than when combined with standard diet.

(49) Animals receiving supplemental KD exhibited reduced tumor growth, seen in FIG. 6, and increased mean survival, seen in FIG. 7 and Table 6. Bioluminescent signal of the luciferase-tagged cancer was measured 21 days after tumor cell inoculation. As seen in FIG. 8, VM cells metastasized throughout the control animals. Supplementation with KE or BD greatly reduced tumor growth and reduced metastasis of the tumor, as shown by luciferase signal focused in the abdomen. Further, KD treatment, with KE supplementation, drastically reduced tumor progression with profound effect. While BD supplementation to KD did reduce rumor progression, even more than BD supplementation alone, the effects were considerably less than those seen with KE supplementation, as seen in FIG. 8.

(50) TABLE-US-00006 TABLE 6 The supplemental ketogenic diet increased survival time in mice with systemic metastatic cancer. The treatment cohort group and median survival times are shown. Cohort size Mean survival % increase in Treatment (N) (days) survival time control (SD) 10 35.1 — SDKE 8 52.8 50.4* SDBD 7 47 33.9* KDKE 7 51.6 47.0* KDBD 8 50.3 43.3* *p < 0.05

(51) Supplementation of food with 20% KE (SDKE) or KD-USF ketogenic diet food mixed with 20% KE (KDKE) significantly reduced mouse weight at week 2, with KDKE mice normalizing slightly in weeks 4 and 6, as seen in FIG. 9. KD-Solace ketogenic diet food with 20% BD (KDBD) also exhibited decreased animal weight compared to control and rodent chow mixed with 20% BD (SDBD), though less dramatic than SDKE, as seen in FIG. 9. Blood glucose levels mirrored animal weight correlations, with SDKE, KDKE, and KDBD showing reduced glucose levels compared to controls, as seen in FIG. 10. Unlike the KD treatments disclosed in Example 1, ketone supplementation resulted in significantly higher ketone levels in KDKE and KDBD, at both 7 and 14 days, as seen in FIG. 11.

(52) It was concluded that supplemental ketone administration confers anti-cancer effects when delivered with either standard or ketogenic diet. SDBD mice did not show significant loss of weight but still had effects, indicating that ketones did induce significant results.

Example 3

(53) To determine the anti-cancer effects of KD metabolic therapy and HBO.sub.2T, survival time, rate of tumor growth, body weight, blood glucose, and blood ketones were measured in mice with VM-M3 metastatic cancer treated with KD, HBO.sub.2T, or combined KD+HBO.sub.2T.

(54) As shown above, KD is useful as a metabolic therapy for cancer by reducing availability of glucose, the main energy substrate for tumors, and inhibiting several oncogene pathways such as IGF-1, MYC, mTOR, and Ras. HBO.sub.2T increases oxygen saturation inside tissues, reversing the cancer-promoting effects of tumor-hypoxia and enhancing ROS production which can induce cell death (D'Agostino, et al. (2009) Acute hyperoxia increases lipid peroxidation and induces plasma membrane blebbing in human U87 glioblastoma cells. Neuroscience 159: 1011-1033). While these therapies have been evaluated separately, the overlapping mechanisms mediating their efficacy are significantly enhanced by combining the treatments. Furthermore, even though metastasis is responsible for 90% of cancer deaths, few studies have evaluated metabolic therapy or HBO.sub.2T as a treatment for metastatic cancer. Therefore, the individual and combined anti-cancer effects of the ketogenic diet and HBO.sub.2T were evaluated in the VM-M3 mouse model of metastatic cancer (Huysentruyt, et al. (2008) Metastatic cancer cells with macrophage properties: evidence from a new murine tumor model. International journal of cancer Journal international du cancer 123: 73-84).

(55) Adult male mice (2-4 months of age) were injected subcutaneously in the abdomen with 1 million VM-M3/Fluc cells, as described in Example 1. On the day of tumor inoculation, mice were randomly assigned to a treatment group, as provided in Table 7. With the VM-M3 model, an adipose tumor quickly appeared following inoculation and rapidly metastasized to most major organs, including brain, lungs, liver, spleen, kidneys, and bone marrow (Huysentruyt, et al. (2008) Metastatic cancer cells with macrophage properties: evidence from a new murine tumor model. International journal of cancer Journal international du cancer 123: 73-84).

(56) TABLE-US-00007 TABLE 7 mouse feed groups for treatment Treatment group Treatments (food and pressure treatment) Control Standard diet fed ad libitum; ambient pressure KD-Solace Commercially available (Ketovolve, Solace Nutrition) ketogenic food fed ad libitum; ambient pressure KD-USF Teklad Custom Research Ketogenic diet designed by researchers (Harlan Laboratories) fed ad libitum; ambient pressure SD + HBO.sub.2T Standard diet fed ad libitum + HBO.sub.2T KD + HBO.sub.2T KD-Solace food fed ad libitum + HBO.sub.2T

(57) Control mice were fed standard rodent chow (2018 Teklad Global 18% Protein Rodent Diet, Harlan Laboratories) fed ad libitum. Mice on a diet therapy received their respective diet fed ad libitum in lieu of standard rodent chow. Mice in the KD-Solace treatment group received KD-Solace (Solace Nutrition) ketogenic diet food, mixed 1:1 with H.sub.2O to form a paste. Mice in the KD-USF treatment group received a Teklad Custom Research Diet (Harlan Laboratories) designed by the researchers. The macronutrient information of the diets used in this study is provided in Table 8. The macronutrient ratio of the custom designed KD-USF diet is similar to ketogenic diets with very low carbohydrate (VLC), containing a high percentage of MCT oil (30-40%) and high protein (22%). The KD-USF diet is notably more palatable to the mice. Diets will be continuously replaced to maintain freshness and allow mice to feed ad libitum.

(58) TABLE-US-00008 TABLE 8 Macronutrient information for SD, KD-Solace, and KD-USF. Macronutrient Standard Ketovolve Custom Information Diet (SD) KD-Solace KD-USF % Cal from Fat 6.2 89.2 77.1 % Cal from Protein 18.6 8.7 22.4 % Cal from 75.2 2.1 0.5 Carbohydrate Caloric Density 3.1 Kcal/g 7.12 Kcal/g 4.7 Kcal/g

(59) Mice in the SD+HBO.sub.2T and KD+HBO.sub.2T treatment groups received HBO.sub.2T (100% oxygen) at 2.5 ATA absolute (1.5 ATA gauge) for 90 minutes three times a week (M, W, F) pressurized in a hyperbaric chamber.

(60) Bioluminescent signal of the luciferase-tagged cancer was measured 21 days after tumor cell inoculation. As in the previous Examples, VM cells metastasized throughout the control animals, with KD treatment greatly reducing tumor growth reduced metastasis, seen in FIG. 12. Hyperbaric treatment had a minor effect on reducing tumor growth, whereas the combined treatment using KD and hyperbaric therapy significantly and drastically reduced tumor progression with profound effect, with tumor cells localized to the injection site. Mirroring the bioluminescence studies, animals treated with KD had increased survival time compared to control and hyperbaric-only treated mice, by approximately 14 days, and combined KD-hyperbaric treatment increased survival by approximately 40 days compared to the control and hyperbaric-only treatment, as seen in FIG. 13. Due to the metabolic therapy and HBO.sub.2T target overlapping pathways, combining the KD with HBO.sub.2T were found to result in a synergistic decrease in tumor growth rate and increase in survival, as seen in FIG. 14 and Table 9. The effect was supra-additive compared to either therapy alone, indicating a synergistic mechanism of action.

(61) TABLE-US-00009 TABLE 9 Treatment group cohort size and median survival times. KD-Solace mice exhibited a 34% increase in mean survival time compared to controls (p = 0.0249); KD-HBO.sub.2T mice exhibited an 80% increase in mean survival time compared to controls (p = 0.0082). Cohort size Mean survival % increase in Treatment (N) (days) survival time control (SD) 10 35.1 — KD-Solace 8 48.9  39.3* KD-USF 7 45.1 28.5 SD + HBO.sub.2T 8 38.8 10.5 KD + HBO.sub.2T 7 62.9  80** *p < 0.05 **p < 0.001

(62) Blood was collected from the study animals every 7 days. Blood glucose and βHB concentrations were measured using a commercially available glucose and ketone (βHB) Monitoring System (Nova Biomedical and Abbott Laboratories). Mice were weighed twice weekly for the duration of the study using the AWS-1 Kg Portable Digital Scale (AWS). Blood and weight measurements were taken at the same time of day each week to control for normal fluctuations in feeding or circadian metabolic changes. Survival time was measured as the time in days from cancer cell inoculation to presentation of defined criteria (diminished response to stimuli, loss of grooming or feeding behavior, lethargy, severe ascites, or failure to thrive). At that time, mice were humanely euthanized by CO.sub.2 asphyxiation and survival time noted.

(63) Tumor metastasis was analyzed in greater detail by harvesting the brain, kidneys, lungs, spleen, liver and adipose tissue after euthanization. As seen in FIGS. 15(A) and (B), combined KD-hyperbaric treatment reduced metastasis compared to control, with the kidneys, spleen, and liver showing drastically reduced tumor cell invasion, and reduced tumor cell invasion in the lungs and liver. Due to the blood brain barrier, tumor metastasis was very limited into the brain in both controls and KD-hyperbaric treated animals.

(64) Animals receiving KD had lower glucose, and some body weight loss compared to controls, as seen in FIGS. 16 and 17, respectively. While it was expected that KD treatment would result in higher ketones, results showed a transitory increase in blood ketones, with a non-significant difference at 14 days, as seen in FIG. 18.

(65) Most studies examining the effects of HBO.sub.2T on cancer have focused on solid, primary tumors. Since hypoxia is most prevalent inside large tumors, it is possible that HBO.sub.2T would not be as effective a treatment for metastatic disease compared to solid tumors. When given as individual therapies, the KD but not HBO.sub.2T elicited anti-cancer effects in mice with systemic metastatic cancer. However, combining the KD with HBO.sub.2T elicited profound, supra-additive anti-cancer effects, indicating a synergistic mechanism of action.

Example 4

Determine the Synergistic Potential of Combining Supplemental Ketones with HBO2T as a Treatment for Metastatic Cancer

(66) To determine if supplemental ketone metabolic therapy and HBO.sub.2T work synergistically to inhibit the progression of metastatic cancer, survival time, rate of tumor growth, body weight, blood glucose, and blood ketones were measured in mice receiving supplemental ketones with HBO.sub.2T. To further assess this combination therapy, the extent of organ metastasis in time-matched tumors, blood vessel density, and protein expression of important cancer signaling molecules were examined in VM-M3 mouse tumors ex vivo following treatment with the proposed therapies.

(67) Data indicate that individually, the KD and ketone supplementation inhibit cancer progression, and that combining the KD with HBO.sub.2T had profound synergistic anti-cancer effects. KDKE mice exhibited the lowest blood glucose and highest blood ketone levels of the treatment groups. As previously discussed, lowering blood glucose and elevating blood ketones work through several mechanisms to inhibit cancer growth. Furthermore, KDKE therapy resulted in greater anti-cancer effects than the KD alone. Since KD combined with HBO.sub.2T induced supra-additive anti-cancer effects and KDKE therapy was more efficacious than KD-alone, combining the KDKE diet therapy with HBO.sub.2T elicited an even greater response. To determine the efficacy of these combined treatments, the survival, rate of tumor growth, body weights, blood glucose, and blood ketones was studied in VM-M3 mice receiving KDKE+HBO.sub.2T therapy. To further investigate the synergistic effects of KD, supplemental ketones, and HBO.sub.2T treatment on metastatic cancer, the extent of organ metastasis, blood vessel density, and protein expression of important signaling molecules in tumors ex vivo was measured from VM-M3 mice receiving KD+HBO.sub.2T, KDKE, and KDKE+HBO.sub.2T therapies compared to control animals.

(68) The mechanism of the anti-cancer effects of metabolic therapy and HBO.sub.2T were analyzed using VM-M3 mouse tumors ex vivo. On day 0 of the study, 1 million VM-M3/Fluc cells in 300 μL PBS are subcutaneously implanted into the abdomen of male, as described in the previous example, and randomly assigned to one of the four study groups; SD (Control)—Standard rodent chow fed ad libitum; KD+HBO.sub.2T—KD-Solace ketogenic diet fed ad libitum+HBO.sub.2T; KDKE—KD-USF ketogenic diet with 10% ketone ester fed ad libitum; or KDKE+HBO.sub.2T—KD-USF ketogenic diet with 10% ketone ester fed ad libitum+HBO.sub.2T. Mice in the control group receive standard rodent chow fed ad libitum. Mice in the KD+HBO.sub.2T group receive KD-Solace ketogenic food fed ad libitum. Mice in the KDKE and KDKE+HBO.sub.2T groups receive KD-USF ketogenic diet food mixed at 10% KE and 1% saccharin by volume fed ad libitum.

(69) On day 21 of the study, mice are euthanized by CO.sub.2 asphyxiation and brain, heart, lungs, liver, kidneys, spleen, intestine, and samples of adipose tissue and skeletal muscle will be surgically removed. Immediately following tissue extraction, organs are incubated in 300 μg/mL D-Luciferin in PBS for 5 min. Bioluminescence of the individual organs is imaged using a 1 second exposure time on the Xenogen IVIS Lumina cooled CCD camera (Caliper LS). Metastatic spread is analyzed by measuring intensity of bioluminescent signal (photon count) produced by the organs. Tissues are immediately flash frozen in liquid nitrogen to preserve viability for vessel density and protein expression studies.

(70) Flash frozen hepatic tumor tissue are embedded in OCT compound and cut with a cryostat to produce 10 μm tissue sections for analysis of blood vessel density. Sections are mounted onto histological slides and stained with anti-mouse von Willibrand factor (vWf), an endothelial cell-specific glycoprotein, staining blood vessels brown. Slides are visualized and blood vessel density will be determined by counting the number of vWf+ blood vessels within a region of interest in a blinded manner.

(71) Lung tumor protein expression of Insulin-like Growth Factor-1 (IGF-1), Activated Akt, Activated Mammalian Target of Rapamycin (mTOR), Hypoxia-Inducible Factor-1α (HIF-1α), and Vascular Endothelial Growth Factor (VEGF) are measured by standard western blot techniques using Anti-IGF-1, Anti-Phospho-Akt, Anti-Phospho-mTOR, Anti-HIF-1α, and Anti-VEGF antibodies (Sigma-Aldrich). Protein density will be determined using the GE Typhoon 9400 Imager with ImageQuant TL software (GE Life Sciences).

(72) Combining the KD with HBO.sub.2T or KE confers potent anti-cancer effects in our model; therefore, KDKE+HBO.sub.2T treated mice should demonstrate even greater efficacy with increased survival time and decreased tumor growth rate. All treated mice should demonstrate reduced organ metastasis compared to control animals although it is unclear if this will be due to inhibition of primary tumor growth or effects on the metastatic process itself. Animals treated with HBO.sub.2T will likely demonstrate significantly less tumor vasculature, as hyperoxia inhibits many angiogenic factors known to be overactive in cancer. The proposed signaling molecules should be elevated in relation to the hypoxic and glycolytic phenotype of cancer through mechanisms previously discussed. Therefore, we expect the expression of these molecules to be decreased in animals treated with metabolic therapy and HBO.sub.2T compared to controls.

(73) To gain a greater understanding of the mechanisms of the anti-cancer effects of these treatments, cell proliferation, viability, reactive oxygen species (ROS) production, and cell morphology of VM-M3 cells in vitro following exposure to low and high glucose, ketones, and HBO.sub.2T are measured. The rate of cell proliferation, cell viability, production, and membrane lipid peroxidation induced-changes in cell morphology (indicative of oxidative stress) of VM-M3/Fluc cells in response to treatment with low (3 mM) glucose, high (15 mM) glucose, 5 mM βHB, and HBO.sub.2T (100% O.sub.2, 2.5 ATA) compared to control, non-treated cells. Cells are treated with low glucose (5 mM); high glucose (15 mM); 5 mM βHB; with/without hyperbaric oxygen therapy (100% O.sub.2, 2.5 ATA).

(74) VM-M3/Fluc cells are cultured in Eagle's Minimum Essential Medium with 2 mM L-glutamine, 10% fetal bovine serum, 1% penicillin-streptomycin, and 10 mM D-glucose. Cells will be maintained in a CO.sub.2 incubator at 37° C. in 95% air and 5% CO.sub.2. Cells receiving HBO.sub.2T are placed in a standard hyperbaric chamber and pressurized to 2.5 ATA absolute with 100% O.sub.2 for 90 min. 5 mM HEPES is added to maintain CO.sub.2 concentrations while in HBO.sub.2T chamber.

(75) Cell proliferation rate is measured using the MTT Cell Proliferation Assay (ATCC). Cells are plated onto a 96 well plate and grown to desired density. Cells are treated for 72 hrs with low (5 mM) glucose, high (15 mM) glucose, or 5 mM βHB with or without HBO.sub.2T (100% O.sub.2, 2.5 ATA absolute, for 90 min). In proliferating cells, MTT is reduced to purple formazan which absorbs light at 490-520 nm and whose excitation can be measured using standard fluorescent microscopy and spectrophotometry. Rapidly dividing cells reduce MTT at very high rates, indicating their rate of proliferation. Cell proliferation can also be measured with Ki67 immunohistochemistry staining, cell viability can also be evaluated with the LDH Cytotoxicity Assay (Cayman Chemical).

(76) Cell viability is measured using the LIVE/DEAD Viability/Cytotoxicity Kit for Mammalian Cells (Invitrogen). Cells are grown to desired density on a coverslip and washed with Dulbecco's phosphate-buffered saline (D-PBS). Cells are treated for 72 hrs with low (5 mM) glucose, high (15 mM) glucose, or 5 mM βHB with or without HBO.sub.2T (100% O.sub.2, 2.5 ATA absolute, for 90 min). The two-color fluorescence assay contains two probes which specifically label live or dead cells. Live cells possess ubiquitous intracellular esterases which cleave the non-fluorescent calcein AM into the highly fluorescent calcein. Calcein produces an intense green fluorescence with an excitation/emission of 495/515 nm. Ethidium homodimer-1 (Ethd-1) enters cells with damaged membranes and binds to nucleic acid. Ethd-1 bound to DNA produces a red fluorescence in dead cells with an excitation/emission of 495/635 nm. Live and dead cells are identified and quantified using standard fluorescent microscopy.

(77) Presence of intracellular ROS is measured by detection of superoxide anion (.O.sub.2.sup.−) using 5 μM Dihydroethidium (DHE) following 72 hr treatment of low (5 mM) glucose, high (15 mM) glucose, or 5 mM βHB, with or without HBO.sub.2T (100% O.sub.2, 2.5 ATA, 90 min.). DHE is permeable to the plasma membrane and freely enters the cell where it reacts with .O.sub.2.sup.− to produce the oxidized ethidium. Ethidium intercalates into the DNA and fluoresces red with an excitation/emission of 485/515 nm which will be visualized using confocal fluorescent microscopy. Alternatively, ROS production can also be examined by the CellROX Deep Red Reagent (Invitrogen).

(78) Atomic force microscopy (AFM) is utilized to analyze surface topography of VM-M3 cells in order to detect ultrastructural changes in cell morphology, such as lipid peroxidation-induced membrane blebbing (D'Agostino, et al. (2009) Acute hyperoxia increases lipid peroxidation and induces plasma membrane blebbing in human U87 glioblastoma cells. Neuroscience 159: 1011-1033; D'Agostino, et al. (2012) Development and testing of hyperbaric atomic force microscopy (AFM) and fluorescence microscopy for biological applications. Journal of microscopy 246: 129-142), following treatment with low (5 mM) glucose, high (15 mM) glucose, or 5 mM βHB. Hyperbaric atomic force microscopy (HAFM) will be similarly used to determine the effects of HBO.sub.2T (100% O.sub.2, 2.5 ATA) on VM-M3 cell morphology.

(79) HBO.sub.2T is known to increase ROS production in normal cells and to an even greater extent in cancer cells (Daruwalla & Christophi (2006) Hyperbaric oxygen therapy for malignancy: a review. World journal of surgery 30: 2112-2143). ROS cause oxidative stress, inducing lipid peroxidation-induced membrane blebbing which can be detected by AFM (D'Agostino, et al. (2009) Acute hyperoxia increases lipid peroxidation and induces plasma membrane blebbing in human U87 glioblastoma cells. Neuroscience 159: 1011-1033). As such VM-M3 cells should exhibit significant alterations in cell membrane morphology following HBO.sub.2T. Ketones have been shown to reduce ROS production in healthy tissues (Maalouf, et al. (2007) Ketones inhibit mitochondrial production of reactive oxygen species production following glutamate excitotoxicity by increasing NADH oxidation. Neuroscience 145: 256-264), but it is unclear if they will attenuate ROS production to the same degree in cancer cells. Mitochondrial defects of cancer should limit the ability of βHB to inhibit ROS production lipid peroxidation in the VM-M3 cells. Since glucose restriction, ketone administration, and HBO.sub.2T have been shown to inhibit cancer progression, treatments should decrease proliferation rate and reduce viability in VM-M3 cells. Since metabolic therapy and HBO.sub.2T work by overlapping mechanisms, the anti-cancer effects of low glucose and βHB treatment should be enhanced by HBO.sub.2T.

(80) In the preceding specification, all documents, acts, or information disclosed do not constitute an admission that the document, act, or information of any combination thereof was publicly available, known to the public, part of the general knowledge in the art, or was known to be relevant to solve any problem at the time of priority.

(81) The disclosures of all publications cited above are expressly incorporated herein by reference, each in its entirety, to the same extent as if each were incorporated by reference individually.

(82) It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall there between. Now that the invention has been described, What is claimed is: