Glutathione

31–cysteine-rich protein reverses weight loss in lung cancer patients receiving chemotherapy or radiotherapy

R. Tozer, ^a) P. Tai, ^b) W. Falconer, ^c) T. Ducruet, ^d) A. Karabadjian, ^e) G. Bounous, ^f)

a) Hamilton Regional Cancer Centre, Hamilton, Ontario, Canada. ^b) Radiation Oncology, Allan Blair Cancer Center, Regina, Saskatchewan, Canada, ^c)Cancer Nutrition & Rehabilitation Program, Dept. of Oncology, McGill University, Montreal, Quebec. Canada, ^d) Boreal Primum Inc., Montreal, Quebec, Canada ^e)Medscope Communications Inc., St. Laurent, Quebec, Canada ^f) Immunotec Research Ltd. Vaudreuil, Quebec Canada.

b) ABSTRACT – Oxidative stress plays a role in the tumor-cytotoxic effect of cancer chemotherapy and radiotherapy and also in certain adverse events. In view of these conflicting aspects, a double-blind trial over 6 months has been performed to determine whether a cysteine-rich protein (IMN1207) may have a positive or negative effect on the clinical outcome if compared with casein, a widely used protein supplement low in cysteine. Sixty-six patients with Stage IIIB-IV non-small cell lung cancer were randomly assigned to IMN1207 or casein. Included were patients with a previous involuntary weight loss of ≥3%, Karnofsky status ≥70, and an estimated survival of > 3 months. Thirty-five lung cancer patients remained on study at six weeks. Overall compliance was not different between treatment arms (42-44% or 13g/day). The patients treated with the cysteine-rich protein had a mean increase of 2.5% body weight while casein-treated patients lost 2.6% (P=0.049). Differences in secondary end points included an increase in survival, hand grip force and quality of life. Adverse events were mild or moderate. Further studies will have to show whether the positive clinical effects can be confirmed and related to specific parameters of oxidative stress in the host.

► High cysteine levels linked to lower rates of breast cancer

15 July, 2003; A Prospective Study of Plasma Cysteine and Risk of Breast Cancer. Abstract LB-3
High serum levels of cysteine are linked to a lower risk of breast cancer, according to a presentation at the 94th Annual Meeting of the American Association for Cancer Research (AACR). Women in the group with the highest levels of plasma cysteine had a 56% reduction in the risk of developing breast cancer. These findings suggest that boosting of plasma cysteine levels might have a preventative effect on breast cancer. Cysteine itself appears to be neurotoxic, and researchers in this field have instead looked to the precursors of cysteine for therapeutic use. Preclinical studies previously suggested that cysteine precursors have an anticarcinogenic effect. Whey protein is naturally high in cystine (the disulfide form of the amino acid cysteine) and contains significantly more than many other sources of protein. The protective effect of high cysteine levels appeared to be strongest in women with body mass index levels below 25 and in premenopausal women.

► Whey protein, glutathione protect against prostate cancer

28 May, 2003; Ohio State University [Kent, Harper, and Bomser; Toxicology In Vitro, February, 2003, 17(1):27-33]
New research suggests that whey, a liquid by-product from cheese production, may play a role in helping prevent prostate cancer. Antioxidants such as glutathione have been shown to control cancer-causing free radicals. Cancer researchers suspect that the accumulation of free radicals plays a role in the development of prostate cancer. In the current study, the Ohio State scientists found that treating prostate cells with whey protein elevated glutathione levels in the cells by up to 64 percent. Whey contains the amino acid cysteine - a key ingredient for making glutathione in the body. Cysteine is the amino acid that helps create healthy glutathione levels in the prostate, and glutathione helps keep free radicals under control. "In diseases like cancer, there's usually a reduction in the body's overall capacity to deal with oxidative stress," he continued. The researchers warn that simply eating cheese won't ensure an increase in glutathione levels, because cysteine is contained in the whey that's separated from cheese early in the cheese-making process. But cysteine is also found in foods such as poultry, wheat, broccoli and eggs.

The glutathione antioxidant system is the principal protecting mechanism of the cell and is a crucial factor in the development of the immune response by the immune cells. Experimental data demonstrates that a cysteine-rich whey protein concentrate represents and effective cysteine delivery system for glutathione replenishment during the immune response. Animal experiments showed that the concentrates of whey protein also exhibit anti-cancer activity. Click here to more info

Enchancing effect of patented whey protein isolate on cytotoxicity of an anticancer drug
Tsai WY, Chang WH, Chen CH, Lu FJ. [Nutr Cancer. 2000;38(2):200-8.] To determine the enhancing effect of a whey protein isolate on the cytotoxicity of a potential anticancer drug, baicalein, the human hepatoma cell line Hep G2 was assigned to grow in different media for four days, and cell growth and apoptosis were investigated.....survival rate was significantly lower in cells grown in baicalein + un-denatured whey protein than in cells grown in baicalein alone.....In conclusion, un-denatured whey protein seemed to enhance the cytotoxicity of baicalein by inducing more apoptosis... This is the first study to demonstrate, in vitro, that un-denatured whey protein may function as an adjuvant in cancer treatments.

Nutriceutical Modulation Of Glutathione With A Humanized Native Milk Serum Protein Isolate: Application In AIDS And Cancer
S. Baruchel, G. Viau, R. Olivier, G. Bounous, M.A. Wainberg [Oxidative Stress in Cancer, AIDS, and Neurodegenerative Diseases V Luc Montagnier et al., (Ed.) Marcel Dekker Inc., New York: 447-461, 1998 . ABSTRACT V] The biological activity of the proteins isolated from cow's milk in un-denatured whey protein depends on the preservation of those labile proteins which share with the predominant human milk proteins the same extremely rare glutathione (GSH)-promoting components. In a pilot study, this type of whey protein concentrate was found to be well tolerated in children with AIDS and wasting syndrome and was found associated with an improvement of the nutritional status of the patient.

Whey proteins in cancer prevention
Bounous G, Batist G, Gold P. [Cancer Lett. 1991 May 1;57(2):91-4. Review.] Epidemiological and experimental studies suggest that dietary milk products may exert an inhibitory effect on the development of several types of tumors......the antitumor activity of the dairy products is in the protein fraction and more specifically in the whey protein component of milk......Whey protein is particularly rich in substrates for GSH synthesis. We suggest that whey protein may be exerting its effect on carcinogenesis by enhancing GSH concentration.

Whey protein concentrate (WPC) and glutathione modulation in cancer treatment
Bounous G. [Anticancer Res. 2000 Nov-Dec;20(6C):4785-92. Review.] Whey protein concentrate has been shown to represent an effective and safe cysteine donor for GSH replenishment during GSH depletion in immune deficiency states........the concentrates of whey proteins also exhibit anti-carcinogenesis and anticancer activity........and may have anti-tumor effect on low volume of tumor via stimulation of immunity through the GSH pathway......Case reports.....strongly suggest an anti-tumor effect of a whey protein dietary supplement in some urogenital cancers. This non toxic dietary intervention, which is not based on the principles of current cancer chemotherapy, will hopefully attract the attention of laboratory and clinical oncologists.

In vitro selective modulation of cellular glutathione by a humanized native milk protein isolate in normal cells and rat mammary carcinoma model
Baruchel S, Viau G. [Anticancer Res. 1996 May-Jun;16(3A):1095-9.] We report the in vitro selective inhibitory activity of a humanized whey protein concentrate on growth of mammary carcinoma cells and Jurkat T cells in comparison to normal peripheral blood mononuclear cells. We relate this inhibitory activity to a selective depletion of intracellular glutathione synthesis. The use of humanized whey protein concentrate as a food supplementation may have direct implication in clinical trial with adjuvant chemotherapy.

Effect of adding glutathione (GSH) to cisplatin (CDDP) in the treatment of stage I-IV ovarian cancer:
(Meeting abstract). Bowman A; Perren T; Wilkinson P; Prescott RJ; Quinn KJ; Tedeschi M; Smyth [JF Address: ICRF Medical Oncology Unit, Edinburgh, UK Source: Br J Cancer 1994;71(Suppl 24):14] Abstract: Previous studies have suggested that glutathione (GSH) can reduce the toxicities of cisplatin (CDDP) chemotherapy. In a double-blind phase III study conducted at 9 British oncology centers... GSH reduced depression and significantly improved 8 other symptoms including emesis and peripheral neurotoxicity. Thus, the addition of GSH to CDDP allows more cycles of CDDP to be administered; quality of life is improved and response rates may be enhanced.

The use of a whey protein concentrate in the treatment of patients with metastatic carcinoma: a phase I-II clinical study
Kennedy RS, Konok GP, Bounous G, Baruchel S, Lee TD. [Anticancer Res. 1995 Nov-Dec;15(6B):2643-9.] Glutathione (GSH) concentration is high in most tumour cells and this may be an important factor in resistance to chemotherapy.........experiments have shown a differential response of tumour versus normal cells to various cysteine delivery systems.........at concentrations that induce GSH synthesis in normal human cells, a specially prepared whey protein concentrate caused GSH depletion and inhibition of proliferation in human breast cancer cells. On the basis of this information five patients with metastatic carcinoma of the breast, one of the pancreas and one of the liver were fed 30 grams of this whey protein concentrate daily for six months.......The results indicate that whey protein concentrate might deplete tumour cells of GSH and render them more vulnerable to chemotherapy.

Dairy proteins protect against dimethylhydrazine-induced intestinal cancers in rats
McIntosh GH, Regester GO, Le Leu RK, Royle PJ, Smithers GW. [J Nutr. 1995 Apr;125(4):809-16.] Whey and casein diets were more protective against the development of intestinal tumors than were the red meat or soybean diets......Intracellular concentration of glutathione, an antioxidant and anticarcinogenic tripeptide, measured in liver, was greatest in whey protein- and casein-fed rats and lowest in soybean-fed animals.....Whatever the mechanism(s), dairy proteins, and whey proteins in particular, offer considerable protection to the host against dimethylhydrazine-induced tumors relative to the other protein sources examined.

Effect of whey protein isolate on intracellular glutathione and oxidant-induced cell death in human prostate epithelial cells
Kent KD, Harper WJ, Bomser JA. [Toxicol In Vitro. 2003 Feb;17(1):27-33.] The objective of this study was to determine whether enzymatically hydrolyzed whey protein isolate (WPI) could increase intracellular GSH concentrations and protect against oxidant-induced cell death in a human prostate epithelial cell line (designated RWPE-1). Treatment of RWPE-1 cells with hydrolyzed WPI significantly increased intracellular GSH by 64%, compared with control cells receiving no hydrolyzed WPI. A similar increase in GSH was observed with N-acetylcysteine, a cysteine-donating compound known to elevate intracellular GSH. Hydrolyzed WPI significantly protected RWPE-1 cells from oxidant-induced cell death, compared with controls receiving no WPI. The results of this study indicate that WPI can increase GSH synthesis and protect against oxidant-induced cell death in human prostate cells.

Whey protein isolate increases glutathione levels in human prostate epithelial cells
K. D. Kent, J. A. Bomser, and W. J. Harper. [Annual Meeting and Food Expo - Anaheim, California, Session 73, Dairy Foods: Probiotics and bioactive components in milk] Prostate cancer is the second leading cause of cancer death among American men. Studies suggest that dietary whey proteins may reduce the risk for cancer by increasing cellular levels of the antioxidant glutathione. Whey proteins are rich in cysteine, the hypothesized rate-limiting amino acid for glutathione synthesis. Supplementation with whey protein isolate may represent a means to increase glutathione synthesis within the prostate. The objective of this study was to determine the effect of whey protein isolate supplementation on glutathione levels in human prostate epithelial cells (RWPE-1).... an increase in available cysteine is responsible for the elevation of glutathione within the prostate epithelial cells.... hydrolyzed whey protein isolate can significantly increase glutathione levels within the prostate epithelium. This represents a potential mechanism by which whey protein isolate can provide protection against the development of prostate cancer.

Glutathione depletion causes cell growth inhibition and enhanced apoptosis in pancreatic cancer cells
Schnelldorfer T, Gansauge S, Gansauge F, Schlosser S, Beger HG, Nussler AK. [Cancer. 2000 Oct 1;89(7):1440-7.] Recent studies have demonstrated that various tumors express enhanced levels of the radical scavenger glutathione (GSH). Moreover, there are grounds for claiming that GSH plays a crucial role in cell proliferation and tumor resistance. In the current study, we investigated the relation between cell growth and GSH levels in the pancreatic adenocarcinoma cell line, AsPC-1, and the significance of GSH in tumor resistance to chemotherapy. Analysis of GSH in pancreatic tissues demonstrated increased GSH levels in cancerous compared with normal tissue. Our results show enhanced GSH levels in pancreatic carcinoma and an essential role of GSH in cell proliferation and in resistance of AsPC-1 cells. Therefore, GSH-depletion may improve the efficacy of adjuvant therapy in pancreatic carcinoma.

Milk and dairy products in cancer prevention: focus on bovine lactoferrin
Tsuda H, Sekine K, Ushida Y, Kuhara T, Takasuka N, Iigo M, Han BS, Moore MA. [Mutat Res 2000 Apr;462(2-3):227-33] Whey protein may also be beneficial, as shown by both animal and human studies, and experimental data have demonstrated that the major component bovine lactoferrin (bLF), inhibits colon carcinogenesis in the post-initiation stage in male F344 rats treated with azoxymethane (AOM) without any overt toxicity.... bLF might find application as a natural ingredient of milk with potential for chemoprevention of colon and other cancers.

Cancer prevention by bovine lactoferrin and underlying mechanisms--a review of experimental and clinical studies
Tsuda H, Sekine K, Fujita K, Ligo M. [Biochem Cell Biol. 2002;80(1):131-6.] In experimental studies, bovine lactoferrin (bLF) has been found to significantly inhibit colon, esophagus, lung, and bladder carcinogenesis in rats when administered orally in the post-initiation stage. Furthermore, concomitant administration with carcinogens resulted in inhibition of colon carcinogenesis.. Anti-metastatic effects were moreover detected when bLF was given intragastrically to mice bearing highly metastatic colon carcinoma 26 cells (Co 26Lu), with apparent enhancing influence on local and systemic immunity. Marked increase in the number of cytotoxic T and NK cells in the mucosal layer of the small intestine and peripheral blood cells was thus found, this in turn enhancing the production of Interleukin 18 (IL-18) and caspase-1 in the epithelial cells of the small intestine, with possible consequent induction of interferon (IFN)-gamma positive cells. Furthermore, bLF has been found to exert anti-hepatitis C virus (HCV) activity in a preliminary clinical trial in patients with chronic active hepatitis due to this virus, a main causative factor in hepatocellular carcinoma development in Japanese. More extensive clinical trials are now underway in the National Cancer Center Hospital and other institutes to further explore the preventive potential against colon carcinogenesis.

Prevention of colon carcinogenesis and carcinoma metastasis by orally administered bovine lactoferrin in animals
Tsuda H, Sekine K, Takasuka N, Toriyama-Baba H, Iigo M. [Biofactors 2000;12(1-4):83-8] Bovine lactoferrin (bLF), a milk protein known to have bacteriostatic properties was examined for its preventive effects on colon and other organ carcinogenesis and experimental metastasis. .. Results of those experiments indicate that bLF remarkably prevents colon carcinogenesis and lung metastasis of colon carcinoma cells, possibly due to increasing cytotoxic cells in the peripheral blood.

Modulation of glutathione by a cysteine pro-drug enhances in vivo tumor response
Wang T, Chen X, Schecter RL, Baruchel S, Alaoui-Jamali M, Melnychuk D, Batist G. [J Pharmacol Exp Ther 1996 Mar;276(3):1169-73] Glutathione (GSH) is known to play a role in cellular sensitivity to some chemotherapeutic agents and to radiation. Depletion of cellular glutathione increases toxicity of these drugs, and this approach is being explored in the clinic as a form of biochemical modulation using the drug buthionine sulfoximine.... some drug-resistant cell lines have increased GSH levels, ... enhancing glutathione concentrations in animal tissues protects against a variety of xenobiotic agents, suggests a different potential approach to improve anticancer therapy. This report describes evidence that OTZ provides this effect in an in vivo rat mammary tumor model... the lack of increased GSH in tumor in response to OTZ.

Glutathione based approaches to improving cancer treatment
Kauvar LM, Morgan AS, Sanderson PE, Henner WD. [Chem Biol Interact. 1998 Apr 24;111-112:225-38.]
The use of cytotoxic chemotherapy for cancer therapy has been very successful in the treatment and often cure of patients with particular neoplasms, such as testicular carcinomas and some lymphomas. In addition, the use of adjuvant chemotherapy in patients whose primary tumor has been surgically removed contributes significantly to cure rates in some of the more common malignancies such as breast carcinoma and colon cancer. Nonetheless, for most patients with metastatic malignancies, current antineoplastic drugs provide only brief remissions with few or no long term cures. In addition, the side effects of therapy lead to substantial morbidity in nearly all patients. Insights derived from model system studies on two glutathione based lead compounds, TER286 and TER199, suggest new clinical strategies and raise interesting basic research questions regarding the cell biology foundations of cancer chemotherapy.

Selective modulation of glutathione levels in human normal versus tumor cells and subsequent differential response to chemotherapy drugs
Russo A., Degraff W., Friedman N., Mitchell EB. [Cancer Res. 26: 2845-48,1986.] Cellular glutathione (GSH) levels were found to be 7-fold higher in a human lung adenocarcinoma cell line (A549) than in a normal human lung fibroblast line (CCL-210). These studies demonstrate that selective differential chemotherapy responses of normal versus tumor cells is possible by manipulating the GSH synthetic cycle.... such manipulation in GSH levels might yield a therapeutic gain for carefully selected chemotherapy drugs.

Glutathione and glutathione-dependent enzymes in cancer drug resistance
McLellan LI, Wolf CR. [Drug Resist Updat 1999 Jun;2(3):153-164] Glutathione and glutathione-dependent enzymes play a central role in cellular defence against toxic environmental agents. Modulation of cellular glutathione homeostasis can also have a profound effect on the sensitivity of cancer cells to a wide range of drugs used in chemotherapy. New data demonstrating the importance of these pathways in cytoprotection and greater understanding of the mechanisms which regulate their function reveal a number of new targets for novel anti-cancer agents.

Glutathione level and its relation to radiation therapy in patients with cancer of uterine cervix
Mukundan H, Bahadur AK, Kumar A, Sardana S, Naik SL, Ray A, Sharma BK.[Indian J Exp Biol. 1999 Sep;37(9):859-64.] The study was aimed to determine plasma glutathione as well as erythrocyte glutathione and glutathione peroxidase in patients with invasive cervical carcinoma before initiation and after completion of radiotherapy and subsequently, at the time of first three monthly follow-up visit. The levels of plasma glutathione, erythrocyte glutathione and glutathione peroxidase activity were found to be lower in all cervical cancer patients as compared to age matched normal control women. The study indicates a change in antioxidant status in relation with the glutathione system among patients with invasive carcinoma of the uterine cervix. This study also demonstrates the effect of radiation therapy on this antioxidant system.

Glutathione and lipid peroxidation levels in human breast tumors
Coban T, Mabsout A, Eke BC, Bulbul D, Berberoglu U, Iscan M. [Neoplasma. 1998;45(3):151-6.] The levels of reduced glutathione (GSH) and lipid peroxidation (LP) of breast tumor and surrounding tumor free (normal) tissues of 39 breast cancer female patients with infiltrating ductal carcinoma and the relationship between these two parameters were investigated. Large interindividual variations in the levels of GSH and LP were found in both tumor and normal tissues. The mean GSH levels of tumors were significantly higher than those of normal tissues. This tendency did not change with the stage and grade (excluding grade 1) of the malignancy, menopausal status and chemotherapy treatment. These results reveal that the GSH, but not LP, could be a marker of breast malignancy and that the increase in GSH level is not sufficient to lower the LP level in human breast tumors.

Colon cancer: dietary modifications required for a balanced protective diet
McIntosh GH. [Prev Med 1993 Sep;22(5):767-74] When comparing differing protein sources, whey protein concentrate was found to be very protective relative to red meat and other protein sources. Protein sources such as whey protein concentrate, insoluble dietary fiber from barley grain, and high calcium intake seem to be very promising. They may provide greater potential than attempts to lower the fat in the human diet.

Apoptosis and tumor cell death in response to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

Department for Experimental Medical Sciences, Section for Lungbiology, Lund, Sweden.

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human milk that kills tumor cells by a process resembling programmed cell death. The complex consists of partially unfolded alpha-lactalbumin and oleic acid, and both the protein and the fatty acid are required for cell death. HAMLET has broad antitumor activity in vitro, and its therapeutic effect has been confirmed in vivo in a human glioblastoma rat xenograft model, in patients with skin papillomas and in patients with bladder cancer. The mechanisms of tumor cell death remain unclear, however. Immediately after the encounter with tumor cells, HAMLET invades the cells and causes mitochondrial membrane depolarization, cytochrome c release, phosphatidyl serine exposure, and a low caspase response. A fraction of the cells undergoes morphological changes characteristic of apoptosis, but caspase inhibition does not rescue the cells and Bcl-2 overexpression or altered p53 status does not influence the sensitivity of tumor cells to HAMLET. HAMLET also creates a state of unfolded protein overload and activates 20S proteasomes, which contributes to cell death. In parallel, HAMLET translocates to tumor cell nuclei, where high-affinity interactions with histones cause chromatin disruption, loss of transcription, and nuclear condensation. The dying cells also show morphological changes compatible with macroautophagy, and recent studies indicate that macroautophagy is involved in the cell death response to HAMLET. The results suggest that HAMLET, like a hydra with many heads, may interact with several crucial cellular organelles, thereby activating several forms of cell death, in parallel. This complexity might underlie the rapid death response of tumor cells and the broad antitumor activity of HAMLET.

Molecular characterization of alpha-lactalbumin folding variants that induce apoptosis in tumor cells.

Institute of Laboratory Medicine, Section of Microbiology, Immunology, and Glycobiology (MIG), Lund University, Sölvegatan 23, S-223 62 Lund, Sweden. Malin.Svensson@mig.lu.se

This study characterized a protein complex in human milk that induces apoptosis in tumor cells but spares healthy cells. The active fraction was purified from casein by anion exchange chromatography. Unlike other casein components the active fraction was retained by the ion exchanger and eluted after a high salt gradient. The active fraction showed N-terminal amino acid sequence identity with human milk alpha-lactalbumin and mass spectrometry ruled out post-translational modifications. Size exclusion chromatography resolved monomers and oligomers of alpha-lactalbumin that were characterized using UV absorbance, fluorescence, and circular dichroism spectroscopy. The high molecular weight oligomers were kinetically stable against dissociation into monomers and were found to have an essentially retained secondary structure but a less well organized tertiary structure. Comparison with native monomeric and molten globule alpha-lactalbumin showed that the active fraction contains oligomers of alpha-lactalbumin that have undergone a conformational switch toward a molten globule-like state. Oligomerization appears to conserve alpha-lactalbumin in a state with molten globule-like properties at physiological conditions. The results suggest differences in biological properties between folding variants of alpha-lactalbumin.

Bladder cancers respond to intravesical instillation of HAMLET (human alpha-lactalbumin made lethal to tumor cells).

Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.

We studied if bladder cancers respond to HAMLET (human alpha-lactalbumin made lethal to tumor cells) to establish if intravesical HAMLET application might be used to selectively remove cancer cells in vivo. Patients with nonmuscle invasive transitional cell carcinomas were included. Nine patients received 5 daily intravesical instillations of HAMLET (25 mg/ml) during the week before scheduled surgery. HAMLET stimulated a rapid increase in the shedding of tumor cells into the urine, daily, during the 5 days of instillation. The effect was specific for HAMLET, as intravesical instillation of NaCl, PBS or native alpha-lactalbumin did not increase cell shedding. Most of the shed cells were dead and an apoptotic response was detected in 6 of 9 patients, using the TUNEL assay. At surgery, morphological changes in the exophytic tumors were documented by endoscopic photography and a reduction in tumor size or change in tumor character was detected in 8 of 9 patients. TUNEL staining was positive in biopsies from the remaining tumor in 4 patients but adjacent healthy tissue showed no evidence of apoptosis and no toxic response. The results suggest that HAMLET exerts a direct and selective effect on bladder cancer tissue in vivo and that local HAMLET administration might be of value in the future treatment of bladder cancers. (c) 2007 Wiley-Liss, Inc.