Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Dunning tumor, originally described as a carcinoma of the rat dorsal prostate, has for long been used as an experimental model of prostatic cancer. We have recently presented a number of morphological findings that are incompatible with the prostatic origin of the H-subline of the Dunning tumor. In this paper, biochemical and immunohistochemical markers of rat prostate and mammary gland are studied in the R-3327 Dunning H tumor. Pieces of the H tumor were inoculated in male or lactating female rats. The electrophoretic protein pattern of Dunning tumor extracts was more similar to that of the mammary gland than the dorsolateral prostate. Proteins selectively appearing after metabolic labeling in Dunning tumors grown in lactating rats corresponded to labeled proteins in mammary glands from the same animals. Secretory proteins typical of the lateral prostate (SVS II) and dorsal prostate (transglutaminase) could not be detected immunohistochemically in the Dunning tumor. Western blot studies of tumor extracts and slot blot analysis of RNA preparations from the tumor confirmed the absence of SVS II and prostate specific transglutaminase from the Dunning tumor. On the other hand, the presence of mammary gland proteins such as milk fat globule membrane proteins, lactoperoxidase and lactalbumin were detected in the Dunning tumor by immunohistochemistry and Western blotting, but were absent from the dorsolateral prostate. Transferrin-mRNA, expressed in the male urogenital tract and also in the liver and other tissues, was detected in the mammary gland and Dunning tumor, but not in the dorsolateral prostate. The absence of mammary gland secretory beta-casein in the Dunning tumor was related to the elevated Ha-ras oncogene expression in the tumor, previously reported to suppress casein expression. The findings clearly demonstrate that the prostate cannot be the origin of the Dunning tumor, presently being used in prostatic cancer research. The designation prostatic adenocarcinoma for this tumor is therefore invalid. Furthermore, the data support our view that mammary gland might be the origin of the Dunning tumor, although the derivation from the bulbourethral or the parotid glands cannot strictly be excluded.
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PMID:Arguments against the prostatic origin of the R-3327 Dunning H tumor. 135 78

The combined effects of dietary fat and protein concentration on prostate tumor growth and endocrine homeostasis were evaluated in male rats. A 2 x 2 factorial experiment examined the effects of protein (5 and 20% of energy as casein) and fat (10 and 40% of energy as corn oil) on the growth of the Dunning R3327-H transplantable prostate adenocarcinoma in Copenhagen x Fisher F1 rats. Rats fed protein-restricted diets for 20 wk exhibited lower energy intakes, final body weights and tumor growth rates. Weanling male Sprague-Dawley rats fed protein-restricted diets for 4 wk had serum concentrations of prolactin, growth hormone and testosterone which were 68, 17 and 85% of controls, respectively. After 16 wk of feeding, there were no effects of dietary protein on serum hormone concentrations despite reduced energy intake and body weight. The metabolic clearance rate of serum prolactin was lower in rats fed the low protein diets for 4 or 16 wk; however, no differences were noted when adjusted for body weight. In vivo studies employing intravenously injected 125I-labeled prolactin revealed slight alterations in the metabolism of circulating prolactin monomer or binding to serum proteins in protein-restricted rats. The maximal binding capacity of prolactin receptors on the prostate membrane fraction was 42% lower in rats fed diets restricted in protein despite normal serum hormone concentrations at 16 wk. Dietary fat had no effect on tumor growth or prolactin homeostasis although a slightly greater serum testosterone was noted in rats fed high fat diets. In contrast, restriction of dietary protein caused significant changes in energy intake, serum hormone concentrations, prolactin metabolism, prostatic prolactin binding capacity and prostate tumor growth rates. These studies support the hypothesis that dietary protein and energy intake, particularly during periods of rapid growth and development, may alter prostate biology and modulate the risk of future prostate cancer progression.
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PMID:Dietary fat and protein intake differ in modulation of prostate tumor growth, prolactin secretion and metabolism, and prostate gland prolactin binding capacity in rats. 903 22

Opioid agonists (ethylketocyclazocine, etorphine, [D-Ala2,D-Leu5]enkephalin (DADLE), [D-Ala2, N-Me-Phe4-Gly-ol]enkephalin (DAGO), [D-Ser2,Leu5]enkephalin-Thr6 (DSLET) and morphine were found to inhibit the proliferation of human prostate cancer cell lines (LNCaP, DU145, and PC3), in a dose-dependent manner. The 50% inhibitory concentrations (IC50) were in the picomolar range. In many cases, this effect was antagonized by the general opioid antagonist, diprenorphine, indicating the existence of specific opioid binding sites. Saturation binding experiments with selective ligands and effectors showed no opioid sites on the LNCaP cell line, kappa1 and mu sites on the PC3 cell line, and kappa1, kappa3 and mu sites on the DU145 cell line. In other cases, the opioid effect was not antagonized by diprenorphine, indicating that the action of opioids might be mediated through other membrane receptors. Furthermore, casomorphin peptides, issued from bovine alpha- (alpha-casein-90-95 and alpha-casein-90-96) and beta-caseins (beta-casomorphin and beta-casomorphin-1-5), and human alphaS1-casein (alphas -casomorphin and alphaS1-casomorphin amide) inhibited cell proliferation of human prostate cell lines, also by a mechanism partly involving opioid receptors. As opioid neurons can be found in the prostate gland, and casomorphin peptides might reach the gland through the general circulation, the above findings indicate a putative role of opioids in prostate cancer cell growth.
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PMID:Opioid alkaloids and casomorphin peptides decrease the proliferation of prostatic cancer cell lines (LNCaP, PC3 and DU145) through a partial interaction with opioid receptors. 936 81

We have developed an assay specific for the PSA-ACT (PSA-alpha 1-antichymotrypsin) complex that effectively diminishes the problem of high assay background commonly reported by other investigators. The assay follows a two-site ELISA format. Polyclonal anti-PSA antibodies were coated on the microplate to capture the PSA complex from the serum, whereas the biotinylated anti-ACT polyclonal antibodies and HRP-conjugated streptavidin were used for detection. The high background ordinarily associated with this assay was greatly reduced when milk casein was added in addition to albumin for blocking and when the Super Block was also included in the diluents for sample dilution and dilution of enzyme conjugated detecting antibodies. The assay has a sensitivity of 0.05 ng/mL. The within-run precision ranges from 4.2-7.2% and the between-run precision falls between 5.8-8.5%. Cross reactions with ACT and free PSA (fPSA) are 0.0001% and 0.02%, respectively. The highest concentration of PSA-ACT complex in the maternal sera was < 0.4 ng/mL by this assay, much less than reported in the literature. Using this improved assay, the sum of fPSA and PSA-ACT concentrations were less than that of their corresponding total PSA (tPSA) most of the time. We believe that this improved assay should be used to replace the current tPSA assay for screening, monitoring, and managing patients with prostate cancer.
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PMID:Development of an immunoassay specific for the PSA-ACT complex without the problem of high background. 948 64

The objectives of our studies are to characterize the ability of dietary soybean components to inhibit the growth of prostate cancer in mice and alter tumor biomarkers associated with angiogenesis. Soy isoflavones (genistein or daidzein) or soy phytochemical concentrate inhibit the growth of prostate cancer cells LNCaP, DU 145 and PC-3 in vitro, but only at supraphysiologic concentrations, i.e., 50% inhibitory concentration (IC(50)) > 50 micromol/L. G2-M arrest and DNA fragmentation consistent with apoptosis of prostate cancer cells are also observed at concentrations causing growth inhibition. In contrast, the in vitro proliferation of vascular endothelial cells was inhibited by soy phytochemcials at much lower concentrations. We evaluated the ability of dietary soy phytochemical concentrate and soy protein isolate to inhibit the growth of the LNCaP human prostate cancer in severe combined immune-deficient mice. Mice inoculated subcutaneously with LNCaP cells (2 x 10(6)) were randomly assigned to one of the six dietary groups based on the AIN-76A formulation for 3 wk. A 2 x 3 factorial design was employed with two protein sources (20%, casein vs. soy protein) and three levels of soy phytochemical concentrate (0, 0.2 and 1.0% of the diet). Soy components did not alter body weight gain or food intake. Compared with casein-fed controls, the tumor volumes after 3 wk were reduced by 11% (P = 0.45) by soy protein, 19% (P = 0.17) by 0.2% soy phytochemical concentrate, 28% by soy protein with 0.2% soy phytochemical concentrate (P < 0.05), 30% by 1.0% soy phytochemical concentrate (P < 0.05) and 40% by soy protein with 1.0% soy phytochemical concentrate (P < 0.005). Histologic examination of tumor tissue showed that consumption of soy products significantly reduced tumor cell proliferation, increased apoptosis and reduced microvessel density. The angiogenic protein insulin-like growth factor-I was reduced in the circulation of mice fed soy protein and phytochemical concentrate. Our data suggest that dietary soy products may inhibit experimental prostate tumor growth through a combination of direct effects on tumor cells and indirect effects on tumor neovasculature.
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PMID:Soybean phytochemicals inhibit the growth of transplantable human prostate carcinoma and tumor angiogenesis in mice. 1046 Jan 96

Epidemiological studies suggest that high intake of dietary fat is a risk factor for the development of clinical prostate cancer. Soy protein has also been proposed to play a role in the prevention of prostate cancer, and one of the isoflavones in soy protein, genistein, inhibits the growth of human prostate cancer cell lines in vitro. This study was designed to evaluate whether altering dietary fat, soy protein, and isoflavone content affects the growth rate of a human androgen-sensitive prostate cancer cell line (LNCaP) grown in severe-combined immunodeficient (SCID) mice. SCID mice were randomized into four dietary groups: high-fat (42.0 kcal%) + casein, high-fat (42.0 kcal%) + soy protein + isoflavone extract, low-fat (12.0 kcal%) + casein, and low-fat (12.0 kcal%) + soy protein + isoflavone extract. After two weeks on these diets, the mice were injected subcutaneously with 1 x 10(5) LNCaP tumor cells and placed in separate cages (1 mouse/cage) to strictly control caloric intake. Isocaloric diets were given 3 days/wk, and tumor sizes were measured once per week. The tumor growth rates were slightly reduced in the group that received the low-fat + soy protein + isoflavone extract diet compared with the other groups combined (p < 0.05). In addition, the final tumor weights were reduced by 15% in the group that received the low-fat + soy protein + isoflavone extract diet compared with the other groups combined (p < 0.05). In this xenograft model for prostate cancer, there were statistically significant effects on tumor growth rate and final tumor weight attributable to a low-fat + soy protein + isoflavone extract diet.
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PMID:Decreased growth of human prostate LNCaP tumors in SCID mice fed a low-fat, soy protein diet with isoflavones. 1069 66

Based on epidemiological surveys, the low incidence of clinical prostate cancer among aged men in Japan and China were attributed to high consumption of soybean-derived food in which phytoestrogens have numerous anticancer mechanisms. The prostate model in Lobund-Wistar (L-W) rats produce high levels of testosterone (T). They are inherently predisposed to develop induced and spontaneous metastasizing adenocarcinomas, which are (T)-dependent in early stages and T-independent in advanced stages. In the experiment reported here, 2 groups of L-W rats (age 2 months) were fed soy-containing diets: (a) commercial diet L-485 (TekLad) with soy meal; or (b) a soy-free diet (L-474) in which casein was replaced by soy protein isolate/isoflavones (SPII). At age 3 months, all rats were inoculated i.v. with MNU; and 14 months later, 17/58 (29.3%) of rats on diet L-485 developed cancer in avg 12 months, compared to 5/50 (10%) of rats on the SPII diet in avg 12.1 months (P = 0.001). In the latter rats, the serum levels of T, and weights of testes were significantly reduced; but in the former rats, serum levels of T remained elevated, suggesting that soy meal in L-4,85 blocked the estrogenic effects of phytoestrogens.
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PMID:Prevention of induced prostate-related cancer by soy protein isolate/isoflavone-supplemented diet in Lobund-Wistar rats. 1090 71

Tetracyclines (TCs) and their non-antimicrobial analogs (CMTs) have therapeutic potential to inhibit tissue destructive disease processes, such as cancer invasion and metastasis, by inhibiting certain matrix metalloproteinases. Enhanced matrix metalloproteinase-2 (MMP-2; gelatinase A) activity has been correlated to cancer invasiveness, and membrane type MMP (MT1-MMP) expressed by tumor cells is involved in localizing and activating pro-MMP-2, a pathway believed to mediate cancer induced tissue breakdown. CMT-3 (6-demethyl, 6-deoxy, 4-dedimethylamino TC) has been shown to experimentally suppress prostate cancer, colon adenocarcinoma and melanoma invasiveness in cell culture and to inhibit tumor growth and metastasis in vivo and was used in the current in vitro study. Confluent MT1-MMP transfected COS-1 cells were harvested, washed thoroughly, subjected to N(2) cavitation and cell membrane enriched fractions were isolated by sequential centrifugations. This MT1-MMP preparation exhibited (i) pro-MMP-2 activating activity as shown by molecular weight shift of this gelatinase from 72 kDa to 62 kDa using gelatin zymography, and (ii) the ability to degrade both [(3)H-methyl] gelatin and casein at 37 degrees C. Adding CMT-3 at final concentrations of 5--20microM inhibited MT1-MMP gelatinolytic and caseinolytic activity, blocked MT1-MMP activation of pro-MMP-2, and decreased invasiveness (using the Matrigel system) of HT-1080 fibrosarcoma cells. The inhibition of MT1-MMP by CMT-3 may partially explain the inhibition of cancer cell -mediated tissue breakdown and invasiveness by this non-antimicrobial tetracycline analog.
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PMID:CMT-3, a non-antimicrobial tetracycline (TC), inhibits MT1-MMP activity: relevance to cancer. 1117 80

Although it has been shown that the cross-talk between osteoblasts and tumor cells stimulates proliferation and invasion of prostate carcinoma (PCa) cells, the molecular mechanisms underlying this event are largely unknown. In this study, we demonstrated that the PCa cells, PC3, derived from bone metastasis, undergo changes of their invasive capability if grown in the presence of osteoblast-derived conditioned media (OBCM). Specifically, they were able to organize tridimensional structures in Matrigel, such as large branching colonies, tube-like structures and clusters of proliferating cells, after treatment. At the ultrastructural level, we observed that PC3 cells grown in the presence of OBCM presented an increment of membrane activity with a blast of shed membrane vesicles from the cell surface. After 6 h of incubation, protein content was approximately 5-fold more elevated in vesicles isolated from PC3 cells cultured in OBCM than in unstimulated cultures. Gelatin zymography of vesicles collected from OBCM-treated PC3 cells showed an increment of lytic bands of MMP family members identified as pro-enzymatic and active forms of gelatinase A (MMP-2) and gelatinase B (MMP-9). By casein-plasminogen zymography, this latter culture also presented an elevated level of high-molecular weight urokinase plasminogen activator (HMW-uPA). Purified vesicles from OBCM-treated PC3 cells incubated with Matrigel cleaved its components more efficiently than vesicles from untreated PC3 cells. Collectively, these findings indicate that osteoblasts produce factor/s able to modify the invasive capability of prostate cancer cells, increasing the amount of shed vesicles and of their associated lytic enzymes.
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PMID:Osteoblast-conditioned media stimulate membrane vesicle shedding in prostate cancer cells. 1652 40

Benign prostate hyperplasia (BPH) is a common disease in elderly men. Although it is a non-malignant disease, it has a significant detrimental impact on the quality of life in patients with late-stage disease. Owing to the lack of specific markers, diagnosis of early-stage BPH has been proven unsuccessful. Recently, using two-dimensional electrophoresis, we identified a group of prostatic secretory proteins that are specifically produced by BPH cells (Xu et al., Electrophoresis 2003; 24: 1311). In this study, we investigated the potential diagnostic value of one of the secretory proteins, alphas1-Casein, in BPH by inmmunohistological staining of normal, BPH and prostate cancer tissues. We found that 90% (20 out of 22) of BPH tissues showed moderate to strong alphas1-Casein protein expression whereas none of the normal tissues (0 out of 10) and less than 10% of the prostate cancer tissues (3 out of 30) showed similar staining intensity. Our results suggest that alphas1-Casein may be a potential biomarker for early identification of BPH patients.
Prostate Cancer Prostatic Dis 2006
PMID:Evidence of a novel biomarker, alphas1-Casein, a milk protein, in benign prostate hyperplasia. 1668 14


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