Combined treatment with vitamin C and sulindac synergistically induces p53- and ROS-dependent apoptosis in human colon cancer cells.

Sulindac has anti-neoplastic properties against colorectal cancers; however, its use as a chemopreventive agent has been limited due to toxicity and efficacy concerns. Combinatorial treatment of colorectal cancers has been attempted to maximize anti-cancer efficacy with minimal side effects by administrating NSAIDs in combination with other inhibitory compounds or drugs such as l-ascorbic acid (vitamin C), which is known to exhibit cytotoxicity towards various cancer cells at high concentrations. In this study, we evaluated a combinatorial strategy utilizing sulindac and vitamin C. The death of HCT116 cells upon combination therapy occurred via a p53-mediated mechanism. The combination therapeutic resistance developed in isogenic p53 null HCT116 cells and siRNA-mediated p53 knockdown HCT116 cells, but the exogenous expression of p53 in p53 null isogenic cells resulted in the induction of cell death. In addition, we investigated an increased level of intracellular ROS (reactive oxygen species), which was preceded by p53 activation. The expression level of PUMA (p53-upregulated modulator of apoptosis), but not Bim, was significantly increased in HCT116 cells in response to the combination treatment. Taken together, our results demonstrate that combination therapy with sulindac and vitamin C could be a novel anti-cancer therapeutic strategy for p53 wild type colon cancers.

Dietary administration of δ- and γ-tocopherol inhibits tumorigenesis in the animal model of estrogen receptor-positive, but not HER-2 breast cancer.

Tocopherol, a member of the vitamin E family, consists of four forms designated as α, ß, γ, and δ. Several large cancer prevention studies with α-tocopherol have reported no beneficial results, but recent laboratory studies have suggested that δ- and γ-tocopherol may be more effective. In two different animal models of breast cancer, the chemopreventive activities of individual tocopherols were assessed using diets containing 0.3% of tocopherol (α-, δ-, or γ-) or 0.3% of a γ-tocopherol rich mixture (γ-TmT). Although administration of tocopherols did not prevent human epidermal growth factor receptor 2 (HER2/neu)-driven tumorigenesis, δ- and γ-tocopherols inhibited hormone-dependent mammary tumorigenesis in N-methyl-N-nitrosourea (NMU)-treated female Sprague-Dawley rats. NMU-treated rats showed an average tumor burden of 10.6 ± 0.8 g in the control group at 11 weeks, whereas dietary administration of δ- and γ-tocopherols significantly decreased tumor burden to 7.2 ± 0.8 g (P < 0.01) and 7.1 ± 0.7 g (P < 0.01), respectively. Tumor multiplicity was also reduced in δ- and γ-tocopherol treatment groups by 42% (P < 0.001) and 32% (P < 0.01), respectively. In contrast, α-tocopherol did not decrease tumor burden or multiplicity. In mammary tumors, the protein levels of proapoptotic markers (BAX, cleaved caspase-9, cleaved caspase-3, cleaved PARP) were increased, whereas antiapoptotic markers (Bcl-2, XIAP) were inhibited by δ-tocopherol, γ-tocopherol, and γ-TmT. Furthermore, markers of cell proliferation (PCNA, PKCα), survival (PPAR-γ, PTEN, phospho-Akt), and cell cycle (p53, p21) were affected by δ- and γ-tocopherols. Both δ- and γ-tocopherols, but not α-tocopherol, seem to be promising agents for the prevention of hormone-dependent breast cancer.

Vitamin D3 supplementation at 4000 international units per day for one year results in a decrease of positive cores at repeat biopsy in subjects with low-risk prostate cancer under active surveillance.

CONTEXT: We wanted to investigate vitamin D in low-risk prostate cancer. OBJECTIVES: The objective of the study was to determine whether vitamin D(3) supplementation at 4000 IU/d for 1 yr is safe and would result in a decrease in serum levels of prostate-specific antigen (PSA) or in the rate of progression. DESIGN: In this open-label clinical trial (Investigational New Drug 77,839), subjects were followed up until repeat biopsy. SETTING: All subjects were enrolled through the Medical University of South Carolina and the Ralph H. Johnson Veterans Affairs Medical Center, both in Charleston, SC. PATIENTS AND OTHER PARTICIPANTS: All subjects had a diagnosis of low-risk prostate cancer. Fifty-two subjects were enrolled in the study, 48 completed 1 yr of supplementation, and 44 could be analyzed for both safety and efficacy objectives. INTERVENTION: The intervention included vitamin D(3) soft gels (4000 IU). MAIN OUTCOME MEASURES: Adverse events were monitored throughout the study. PSA serum levels were measured at entry and every 2 months for 1 yr. Biopsy procedures were performed before enrollment (for eligibility) and after 1 yr of supplementation. RESULTS: No adverse events associated with vitamin D(3) supplementation were observed. No significant changes in PSA levels were observed. However, 24 of 44 subjects (55%) showed a decrease in the number of positive cores or decrease in Gleason score; five subjects (11%) showed no change; 15 subjects (34%) showed an increase in the number of positive cores or Gleason score. CONCLUSION: Patients with low-risk prostate cancer under active surveillance may benefit from vitamin D(3) supplementation at 4000 IU/d.

Selectively hydrogenated soybean oil exerts strong anti-prostate cancer activities.

Prostate cancer is the second leading cause of male deaths due to cancer in the United States. Hydrogenated vegetable oils have been suspected of inducing adverse health effects, including atherosclerosis and cancer. Here we report that a selectively hydrogenated soybean oil (SHSO) containing a high quantity of conjugated linoleic acids showed remarkably strong anticarcinogenic activity against prostate cancer in the rat model (Copenhagen rats with MAT-LyLu syngeneic rat prostate cancer cells) study in vivo and human prostate carcinoma cell lines studies in vitro, as compared with native soybean oil. A 5% dietary supplementation with SHSO inhibited the growth of prostate cancer by 80% in vivo. The TUNEL method and immunohistochemical staining assays of bax, bcl-2, and survivin clearly showed that SHSO induced prostate cancer cell apoptosis in the tested rats. DNA fragmentation analysis in vitro further confirmed the apoptotic activity of SHSO on the MAT-LyLu prostate cancer cells. The SHSO also showed strong cytotoxicity on human prostate cancer cells (DU145 and PC3). This represents the first report demonstrating the significant anticancer activities of hydrogenated vegetable oils at low levels of dietary supplementation.

Early supplementation of parenteral nutrition is capable of improving quality of life, chemotherapy-related toxicity and body composition in patients with advanced colorectal carcinoma undergoing palliative treatment: results from a prospective, randomized clinical trial.

AIM: Patients suffering from advanced colorectal cancer can experience unintended weight loss and/or treatment-induced gastrointestinal toxicity. Based on current evidence, the routine use of parenteral nutrition (PN) for patients with colorectal cancer is not recommended. This study evaluates the effect of PN supplementation on body composition, quality of life (QoL), chemotherapy-associated side effects and survival in patients with advanced colorectal cancer. METHOD: Eighty-two patients with advanced colorectal cancer receiving a palliative chemotherapy were prospectively randomized to either oral enteral nutrition supplement (PN-) or oral enteral nutrition supplement plus supplemental PN (PN+). Every 6 weeks body weight, body mass index (BMI), chemotherapy-associated side effects and caloric intake were assessed, haemoglobin and serum albumin were measured. Body composition was assessed by body impedance analysis, and QoL was evaluated by European Organization for Research and Treatment of Cancer (EORTC) QLQC30 questionnaire. RESULTS: No differences were evident at baseline between the groups for age, sex, diagnosis, weight, BMI or QoL. A difference in BMI was observed by week 36, whereas differences of the mean body cell mass could be observed from week 6, albumin dropped significantly in the PN- group in week 36 and QoL showed significant differences from week 18. Chemotherapy-associated side effects were higher in PN-. The survival rate was significantly greater in the PN+ group. CONCLUSION: A supplementation with PN slows weight loss, stabilizes body-composition and improves QoL in patients with advanced colorectal cancer. Furthermore, it can reduce chemotherapy-related side effects.

Dietary intervention in the management of prostate cancer.

PURPOSE OF REVIEW: This review integrates recent reports related to the dietary management of prostate cancer with the existing body of science in an effort to best inform practicing clinicians. RECENT FINDINGS: Dietary factors are hypothesized to play a significant role in prostate cancer, and have proven to be important in managing prevalent comorbidities in this patient population (cardiovascular disease, diabetes, and osteoporosis). Data regarding diet and prostate cancer are accumulating and randomized controlled trials are underway which will ultimately yield evidence on which to base recommendations regarding dietary regimens, functional foods, and supplement use. Until that time, most data derive from epidemiologic studies that have limitations in showing cause and effect. During the past year, the greatest and most consistent strides have been made in the area of energy balance, with data consistently showing that overweight and obesity are associated with progressive disease and increased overall mortality. SUMMARY: To date, the strongest evidence regarding diet and prostate cancer relates to energy balance. Urologists aspiring to best clinical practice should encourage their patients to achieve a healthful body weight through regular exercise and a healthful plant-based diet rich in fruits, vegetables, and whole grains. Advocating functional foods or supplements explicitly for cancer control purposes would currently be premature.

Do the dietary supplements epigallocatechin gallate or vitamin e cause a radiomodifying response on tumors in vivo? A pilot study with murine breast carcinoma.

The primary aim of this study was to evaluate a systematic and reproducible assay to examine the potential radiomodifying effects of vitamin E (VE) or epigallocatechin gallate (EGCG), antioxidants commonly consumed by cancer patients as dietary supplements, on tumor control. C3H mice were randomized to a control diet or to the control diet supplemented with VE or EGCG. A tumor control dose 50% (TCD(50)) assay was used to evaluate for a radiomodifying response in stage IV murine cancer (MCa-IV) tumors, implanted in the hindleg of mice, and allowed to grow to 8 mm before receiving a single dose of radiation. The effects of VE and EGCG on intratumoral angiogenesis and apoptosis were evaluated in a group of nonirradiated mice using immunohistochemical staining. Cell proliferation assays were conducted on MCa-IV tumors in vitro. EGCG slowed tumor growth rate by 10%. EGCG and VE slowed tumor regrowth by 24 to 25%. There were no significant differences in TCD(50) values between the groups (control = 73.9 Gy, VE = 77.2 Gy, EGCG = 76.4 Gy); however, normal tissues were protected from late radiation effects (autoamputations) in the VE group. VE and EGCG increased tumor cell apoptosis and decreased tumor cell proliferation but had no effect on microvessel density. In this pilot study, neither VE nor EGCG exerted a significant radiomodifying effect on the MCa-IV tumor. Nonetheless, the suggestion of a small degree of tumor radioprotection by these antioxidant compounds warrants further research. As supplementation with VE radioprotected normal tissue, additional studies on this putative benefit are recommended.

Inhibition of experimental colorectal carcinogenesis by dietary N-6 polyunsaturated fats.

The influence of dietary fats on azoxymethane-induced colorectal carcinogenesis and erythrocyte, adipose, colon mucosa and tumour tissue fatty acids was investigated in 228 Wistar rats. The two main diets compared were beef suet rich in saturated fatty acids and corn oil rich in a linoleic acid, an N-6 polyunsaturated fatty acid. The animals were placed in one of four dietary groups: A = 5% saturated fat, B = 20% saturated fat, C = 5% N-6 fat and D = 20% N-6 fat. There was no difference in the number of adenomas between any of the dietary groups. The mean (+/- SEM) carcinoma yield per rat was A = 0.93 +/- 0.28, B = 1.93 +/- 0.50, C = 0.70 +/- 0.07, D = 0.13 +/- 0.04; the tumour yields in rats fed the saturated fat diets were significantly different from each other and from those fed the N-6 fat diets. The fatty acid profiles in all tissues were dependent upon the type and level of dietary fat and the tissue type. Arachidonate was higher in tumours compared to normal mucosa. Significant correlations were found between adipose linoleate (reflecting dietary intake) and tumour oleate and tumour arachidonate but not with the colorectal mucosa of control animals. This is the first in vivo study to show reduced colorectal carcinogenesis by N-6 polyunsaturated fatty acids.