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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over-consumption of dietary fat has been suggested to promote the development and progression of prostate cancer in men. The present study was conducted to answer the following questions: (a) Can dietary fat reduction decrease tumor growth rates of Los Angeles prostate cancer (LAPC)-4 xenografts in severe combined immunodeficient (SCID) mice independent of total caloric intake? and (b) Is the insulin-like growth factor (IGF) axis involved in the effects of dietary fat on LAPC-4 tumor growth in SCID mice? Twenty-eight male CB17 beige SCID mice (8 weeks old) were individually caged, randomized, and fed an isocaloric high-fat (HF, 42% kcal) or low-fat (LF, 12% kcal) diet. Each mouse was s.c. injected with 1 x 10(5) LAPC-4 cells, and tumor volumes were measured weekly. At week 16, all animals were sacrificed, and serum and tumors were obtained for analysis. Although caloric intakes and mouse weights were equal between groups, the LF mice had significantly slower tumor growth rates and lower serum prostate-specific antigen levels compared with the HF mice. LF mice had significantly lower levels of serum insulin, tumor IGF-1 mRNA expression, and tumor IGFBP-2 immunostaining and higher levels of serum IGFBP-1 (by Western ligand blot) relative to the HF mice. There were no differences in the serum levels of IGFBP-3 and IGFBP-4 between the groups. LAPC-4 cells cultured in vitro with media containing serum from LF mice demonstrated slower growth than LAPC-4 cells cultured in media containing HF mice serum. These results demonstrate that intake of an LF diet was associated with slower LAPC-4 prostate tumor growth relative to mice fed an HF diet, independent of total caloric intake, and this effect may be mediated through modulation of the insulin/IGF axis.
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PMID:Effect of isocaloric low-fat diet on human LAPC-4 prostate cancer xenografts in severe combined immunodeficient mice and the insulin-like growth factor axis. 1285 54

Despite strong indirect evidence that androgens stimulate prostate cancer development, data from most analytical studies on this association have been negative. To further investigate this issue, we studied the interrelationships between androgenicity and insulin-like growth factor I (IGF-I), insulin and leptin. Within a prospective cohort study, we measured testosterone, sex hormone-binding globulin (SHBG) and IGF-I, IGF-binding protein (IGFBP)-1, IGFBP-3, insulin and leptin, in plasma from 149 cases and 298 controls. Testosterone correlated positively with SHBG, whereas testosterone and SHBG correlated inversely with IGF-I, IGFBP-3, insulin, leptin and body mass index (BMI). Indices of free testosterone showed an inverse linear correlation with leptin (P<0.01), and a strong drop in the 5th quintile of BMI. However, levels of free testosterone showed non-linear relationships over quintiles of insulin and IGF-I, with a significant increase in the second quintile of IGF-I compared with other levels. The absence of an association between plasma levels of androgens and prostate cancer risk in analytical studies, despite the strong indirect evidence of their tumour-stimulating effects, may reflect the complex and mostly inverse associations of androgenicity to IGF-I, insulin and leptin which are hormones that have also been implicated as risk factors for prostate cancer.
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PMID:Interrelationships between plasma testosterone, SHBG, IGF-I, insulin and leptin in prostate cancer cases and controls. 1288 84

Prostate cancer is one of the leading causes of death among men in the United States, and acquisition of hormone resistance (androgen independence) by cancer cells is a fatal event during the natural history of prostate cancer. Obesity is another serious health problem and has been shown to be associated with prostate cancer. However, little is known about the molecular basis of this association. Here we show that factor(s) secreted from adipocytes stimulate prostate cancer cell proliferation. Leptin is one of the major adipose cytokines, and it controls body weight homeostasis through food intake and energy expenditure. We identify leptin as a novel growth factor in androgen-independent prostate cancer cell growth. Strikingly, leptin stimulates cell proliferation specifically in androgen-independent DU145 and PC-3 prostate cancer cells but not in androgen-dependent LNCaP-FGC cells, although both cell types express functional leptin receptor isoforms. c-Jun NH2-terminal kinase (JNK) has been shown recently to play a crucial role in obesity and insulin resistance. Intriguingly, leptin induces JNK activation in androgen-independent prostate cancer cells, and the pharmacological inhibition of JNK blocked the leptin stimulation of androgen-independent prostate cancer cell proliferation. This suggests that JNK activation is required for leptin-mediated, androgen-independent prostate cancer cell proliferation. Furthermore, other cytokines produced by adipocytes and critical for body weight homeostasis cooperate with leptin in androgen-independent prostate cancer cell proliferation: interleukin-6 and insulin-like growth factor I demonstrate additive and synergistic effects on the leptin stimulation of androgen-independent prostate cancer cell proliferation, respectively. Therefore, adipose cytokines, as well as JNK, are key mediators between obesity and hormone-resistant prostate cancer and could be therapeutic targets.
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PMID:Prostate cancer cell-adipocyte interaction: leptin mediates androgen-independent prostate cancer cell proliferation through c-Jun NH2-terminal kinase. 1290 51

Familial predisposition together with several environmental factors may be involved in the pathogenesis of common prostate disease such as benign hypertrophy or prostate neoplasm. A higher incidence of both these conditions has been described in some insulin-resistant states such as obesity, but not much information is available on the effect of metabolic profile on gland morphology. The aim of this study was to evaluate the relation between glucose and lipid pattern and prostate diameters in two groups of non-diabetic individuals with benign prostate hypertrophy or cancer. 109 patients were recruited; plasma glucose, lipids and hormonal profile as well as an ultrasonographic evaluation of the gland volume and diameters were determined. Patients with prostate cancer had significantly higher levels of insulin and were more insulin resistant; in contrast, in subjects with prostate hypertrophy, fasting plasma glucose and--to a lesser extent--serum triglycerides emerged as the main determinants of gland volume. These observations may indicate that an improvement of insulin sensitivity and strategies to maintain a strict glucose and lipid control even in non-diabetic subjects are useful objectives in the prevention of prostate diseases.
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PMID:Metabolic profile in patients with benign prostate hyperplasia or prostate cancer and normal glucose tolerance. 1291 99

Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a member of the IGFBP super family, is down-regulated at the mRNA level in several solid cancers. We hypothesize that IGFBP-rP1 has a tumor-suppressive effect on prostate cancer growth and its inactivation is through CpG hypermethylation. We tested this hypothesis through expression analysis of IGFBP-rP1, transfection studies, growth analysis, and CpG methylation in prostate cancer cells and tissues. In situ hybridization revealed IGFBP-rP1 mRNA expression was detected in the stroma and epithelium of benign prostatic hyperplasia tissues but was either weak or lost in prostate cancer tissues. The mRNA expression for IGFBP-rP1 was lacking in DU145, LNCaP, ND-1, and PC-3 prostate cancer cell lines, and after demethylation (5-aza-dC treatment), the expression was restored suggesting that methylation inactivated IGFBP-rP1 expression in prostate cancer cells. We further tested whether transfection of IGFBP-rP1 can modulate prostate cancer cells growth. We transfected PC-3 cell lines with IGFBP-rP1 cDNA (PC-3-rP1) and Northern blotting confirmed mRNA transcript of IGFBP-rP1 in these PC-3-rP1 clones. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed growth rate was significantly lower in PC-3-rP1 cells than in the nontransfected control. In addition, the medium obtained from PC-3-rP1 cells reduced the growth rate in both PC-3-rP1 and control PC-3 cells. A soft agar colony-forming assay revealed that colony formation was markedly decreased in PC-3-rP1 cells. The number of apoptotic cells and caspase-3 expression were increased in the PC-3-rP1 cells as compared with control PC-3 cells. This is the first study that suggests inactivation of IGFBP-rP1 is through CpG methylation, and tumor-suppressive activity of IGFBP-rP1 is through induction of apoptosis in an IGF-I independent manner in prostate cancer.
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PMID:Restoration of insulin-like growth factor binding protein-related protein 1 has a tumor-suppressive activity through induction of apoptosis in human prostate cancer. 1463 96

The incidence of colon, pancreatic, and kidney cancers, as well as aggressive prostate cancer in men, and breast and endometrial cancer in women is invariably high in Western countries. Nutritional and related factors have been typically implicated. This review presents a model integrating nutrition, insulin and IGF-1 physiology ("bioactive" IGF-1), and carcinogenesis based on the following: (1) insulin and the IGF-1 axis function in an integrated fashion to promote cell growth and survival; (2) chronic exposure to these growth properties enhances carcinogenesis; (3) factors that influence bioactive IGF-1 will affect cancer risk. The model presented here summarizes the data that chronic exposure to high levels of insulin and IGF-1 may mediate many of the risk factors for some cancers that are high in Western populations. This hypothesis may help explain some of the epidemiologic patterns observed for these cancers, both from a cross-national perspective and within populations. Of particular importance is that some of relevant factors are modifiable through nutritional and lifestyle interventions. Out of a variety of perspectives presented, nutritional manipulation through the insulin pathway may be more feasible than attempting to influence total IGF-1 concentrations, which are determined largely by growth hormone. Further study is required to test these conclusions.
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PMID:Nutrition, insulin, insulin-like growth factors and cancer. 1471 Mar 48

The Insulin-like Growth Factor (IGF) signaling system plays a central role in cellular growth, differentiation and proliferation. IGFBP-3 is the most abundant IGF binding protein in human serum and has been shown to be a growth inhibitory, apoptosis-inducing molecule, capable of acting via IGF-dependent and IGF-independent mechanisms. Over the last decade, several clinical studies have proposed that individuals with IGFBP-3 levels in the upper range of normal may have a decreased risk for certain common cancers. This includes evidence of a protective effect against breast cancer, prostate cancer, colorectal cancer, and lung cancer. In addition, a series of in vitro studies and animal experiments point towards an important role for IGFBP-3 in the regulation of cell growth and apoptosis. In this brief review, we discuss the biological role of IGFBP-3 and summarize the epidemiological and experimental evidence suggesting a role for IGFBP-3 as an anti-cancer molecule.
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PMID:Epidemiology and biology of insulin-like growth factor binding protein-3 (IGFBP-3) as an anti-cancer molecule. 1471 Mar 51

The issue of a possible relationship between type 2 diabetes and cancer is still debated. Such chronic diseases show a high incidence in the general population. In their pathophysiology both genetic and environmental factors are involved, inducing important modifications of metabolism. Diabetes is associated to profound metabolic alterations, such as hyperinsulinemia and insulin resistance, which are common in various diseases, i.e. obesity, hypertension, dyslipidemia and hyperuricemia. Those illnesses form the so-called metabolic syndrome. Insulin resistance, hyperestrinism and the associated hyperandrogenism may play a role in the onset of some malignancies, such as endometrium cancer, breast cancer and prostate cancer. Low plasma levels of IGF-1 are able to reduce the risk of cancer in type 2 diabetes patients. This goal can be obtained with preventive measures, as physical activity, diet and drugs that can reduce insulin resistance (metformin and thiazolidinediones).
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PMID:Evidence for a putative relationship between type 2 diabetes and neoplasia with particular reference to breast cancer: role of hormones, growth factors and specific receptors. 1503 27

Androgens are important determinants of body composition in men. Androgen-deprivation therapy, the mainstay of treatment for advanced prostate cancer, increases fat mass and decreases lean body mass. These adverse changes in body composition may contribute to treatment-related fatigue, fracture risk, insulin resistance, and increased cardiovascular disease risk. Potential strategies to treat or prevent these adverse body composition changes include exercise training, alternative forms of hormonal therapy, and insulin-sensitizing agents.
Clin Prostate Cancer 2003 Jun
PMID:Changes in body composition during hormonal therapy for prostate cancer. 1504 79

We previously discovered that a fat-metabolizing enzyme, 15-lipoxygenase-1 (15-LO-1), is high in human prostate cancer (PCa) and correlates with disease progression. The biologic link between the aberrant 15-LO-1/linoleic acid (LA) metabolism and fat (which is a rich source of growth factors) in PCa is unknown. Therefore, we tested the hypothesis that the metabolic product of the polyunsaturated fatty acid LA (i.e., 13-S-hydroxyoctadecadienoic acid or 13-(S)-HODE) affects the proliferation status of PCa cells through one or more growth factors. We used parental prostate cancer cell line-3 (PC-3) and engineered PC-3 cell lines [PC3-Zeo (mock-transfected), PC3-15LOS (15-LO-1-overexpressing), and PC3-15LOAS (15-LO-1-blocked)] to test our hypothesis. Of the growth factors examined, only insulin-like growth factor-1 (IGF-1) exhibited a two-fold to three-fold increase in growth response on PC3-15LOS cells compared to PC3-Zeo (control) cell line (P <.01). Insulin-like growth factor-1 receptor (IGF-1R) immunohistochemical analyses of human normal and adenocarcinoma prostate tissues, as well as levels in tumors derived from nude mice injected with PC-3 cells, demonstrated that elevated IGF-1R expression correlated with 15-LO-1 levels. Radioligand binding assays demonstrated two-fold higher IGF-1 binding sites in PC3-15LOS cells (P <.05 vs PC3-Zeo cells). IGF-1R promoter reporter assay and affinity-purified IGF-1R receptor levels demonstrated a four-fold higher activity in PC3-15LOS cells (P <.01 vs PC3-Zeo cells). IGF-1R promoter activation is 13-(S)-HODE-dependent. IGF-1R blockade with a dominant-negative adenovirus caused significant growth inhibition in PC-3 cells (P <.0001; PC3-15LOAS versus PC3-15LOS cells), as well as affected the IGF-1-stimulated mitogen-activated protein (MAP) kinase (Erk1/2) and Akt activation levels. Our study suggests that overexpression of 15-LO-1 in PCa contributes to the cancer progression by regulating IGF-1R expression and activation.
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PMID:15-lipoxygenase-1 expression upregulates and activates insulin-like growth factor-1 receptor in prostate cancer cells. 1506 70


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