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

Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3) is known to block IGF action and inhibit cell growth. IGFBP-3 is thought to act by sequestering free IGFs or, possibly, act via a novel IGF-independent mechanism. Supporting its role as a primary growth inhibitor, IGFBP-3 production has been shown to be increased by cell growth-inhibitory agents, such as transforming growth factor-beta (TGF-beta), and the tumor suppressor gene p53. In this paper, we demonstrate, for the first time, a novel function of IGFBP-3 as an apoptosis-inducing agent and show that this action is mediated through an IGF.IGF receptor-independent pathway. In the p53 negative prostate cancer cell line, PC-3, the addition of recombinant IGFBP-3 resulted in a dose-dependent induction of apoptosis. 125I-IGFBP-3 bound with high affinity to specific proteins in PC-3 cell lysates and plasma membrane preparations. These membrane-associated molecules may serve as receptors that mediate the direct effect of IGFBP-3 on apoptosis. In addition, in an IGF receptor-negative mouse fibroblast cell line, treatment with recombinant IGFBP-3 as well as transfection of the IGFBP-3 gene induced apoptosis, suggesting that neither IGFs nor IGF receptors are required for this action. Furthermore, treatment with TGF-beta1, a known apoptosis-inducing agent, resulted in the induction of IGFBP-3 expression 6-12 h before the onset of apoptosis. This effect of TGF-beta1 was prevented by co-treatment with IGFBP-3-neutralizing antibodies or IGFBP-3-specific antisense thiolated oligonucleotides. These findings suggest that IGFBP-3 induces apoptosis through a novel pathway independent of either p53 or the IGF.IGF receptor-mediated cell survival pathway and that IGFBP-3 mediates TGF-beta1 induced apoptosis in PC-3 cells.
 ...
PMID:Insulin-like growth factor (IGF)-binding protein-3 induces apoptosis and mediates the effects of transforming growth factor-beta1 on programmed cell death through a p53- and IGF-independent mechanism. 911 91

Somatostatin analogues (SMS-A) have been found to inhibit the growth of experimental tumors, as of prostate cancer, via several mechanisms as antihormonal and direct antimitogenic actions. It was demonstrated also that several SMS-A induce greater prostatic tumor regression with more pronounced histological changes if combined with LHRH analogues or in association with complete androgen blockade (CAB). In a phase II clinical trial we administered, in addition to CAB, SMS-A octreotide in 14 patients with stage D2 (group B) prostate cancer-8 previously hormonally treated (PHT) and 6 without any previous hormone treatment (NPHT); 4 other patients, 3 NPHT and one PHT, were treated with CAB only (group A). Antiandrogen and antitumoral activity followed assaying a) plasma testosterone b) prostatic specific antigen (PSA) c) prostatic acid phosphatase (PAP) levels and d) objective (o) and subjective (s) clinical improvement according to WHO criteria. Somatostatin activity was evaluated assaying Insulin like Growth Factor-1 (IGF-1) and Epidermal Growth Factor (EGF). In group B we observed 3 responses, with the best quality of response (oPR/sCR) among the 6 NPHT-patients (50%) and 3 responses among the PHT-patients (37,5%), two of them with an incomplete PHT. In group A, 2 out of 3 NPHT-patients had a response (oPR/sPR). Among group B patients we observed long symptom-free survival, when they responded (17 months), in comparison to group A patients (12 months), but almost the same total duration of survival in the two groups, 18.5 and 18 months, respectively. EGF and IGF-1 serum levels showed a distinct drop parallel to the decrease of PSA serum levels, among the patients with response vs. nonrespondent patients of group B during the treatment. Although our results showed that octreotide in small doses, in addition to CAB, having mild toxicity, enhance number, quality and perhaps the duration of symptom-free responses in patients with stage 2 prostate cancer, the therapeutic efficacy of this combined treatment remains to be ascertained in wider and better randomized clinical trials.
 ...
PMID:The role of somatostatin analogues in complete antiandrogen treatment in patients with prostatic carcinoma. 914 72

Insulin-like growth factors (IGFs) are potent mitogens for a variety of cancer cells in vitro. A paracrine/autocrine role of IGF-II in the growth of breast and prostate cancer cells has been suggested. Information on cell-type-specific IGF-II expression in vivo in the breast and prostate is, however, limited. Thus, cell types expressing IGF-II mRNA and protein in tumors were identified by in situ hybridization and immunohistochemistry. Of 36 prostate, 17 breast, and 10 bladder cancers, and 9 paraganglioma tissues examined, IGF-II was expressed in more than 50% of prostate, breast, and bladder tumors, and in 100% of paraganglioma tumors. Expression levels of IGF-II were highest in the paraganglioma and bladder followed by prostate and breast tumors. In all the tumors expressing IGF-II, both mRNA and protein were localized to malignant cells, expression in the stroma being minimal. Since previous studies had indicated that an incompletely processed form of 15-kDa IGF-II exhibited higher mitogenic potency than the completely processed 7.5-kDa IGF-II form, the quantity and size of IGF-II proteins expressed in these tumors were analyzed by Western immunoblotting. Greater expression of 15-kDa IGF-II relative to the 7.5-kDa IGF-II form was clearly demonstrated in all six prostate cancers and in half of the two breast and four bladder cancers examined. The results are consistent with the hypothesis that the 15-kDa form of IGF-II expressed in cancerous cells contributes to autocrine cancer cell growth in vivo.
 ...
PMID:Expression of insulin-like growth factor (IGF)-II in human prostate, breast, bladder, and paraganglioma tumors. 947 3

Karyotypic analysis was performed on 102 prostate cancer specimens which were obtained through radical prostatectomy, transurethral resection, or regional lymph node dissection. Short term tissue culture was applied in all cases. Of the media and growth factors evaluated, F12/DMEM, supplemented with 2% fetal calf serum, insulin, epidermal growth factor, hydrocortisone, and cholera toxin produced the largest increase of in vitro proliferation. Such in vitro cultured cells were all phenotypically acinar epithelial cells, the supposed targets for neoplastic transformation. Stromal cell growth appeared to be completely suppressed. Of the three culture techniques investigated, the method developed in Lund, Sweden, was the most successful: 11/15 cultures yielded metaphases and, in three of these, clonal aberrations were identified. All 39 karyotypes obtained essentially had a 46,XY karyotype with clonal aberrations (eight cases) and/or nonclonal aberrations (30 cases). Clonal structural aberrations involved 2p, 3q, 11p, 17p, and 21q. The clonal numerical aberrations found were: + 8, + dmin, and -Y. The most frequently observed nonclonal aberrations were 8p deletions (five cases) and loss of 6, 7, 8, 15, 17, 18, 21, and/or Y (> or = five cases). In summary, clonal aberrations were observed in 20% of the evaluable PC cell cultures, and nonclonal aberrations in 77%. So, although diploid cells without clonal abnormalities still had a growth advantage, under optimal conditions PC cells were able to proliferate in primary in vitro culture.
 ...
PMID:Cytogenetic analysis of 39 prostate carcinomas and evaluation of short-term tissue culture techniques. 949 12

The aim of our study was to determine whether leptin, a hormone implicated in both energy-balance and reproductive function, is involved in the etiology of prostate cancer or benign prostatic hyperplasia (BPH). We compared the serum leptin levels of 43 cases of incident prostate cancer, 41 patients with BPH, and 48 healthy controls, all recruited in Athens, Greece. Multiple logistic regression modeling was used, with adjustment for age, height, body mass index, education, estradiol, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin and insulin like growth factor 1. Odds ratios per 4 ng/ml increment of leptin were 0.70 [95% confidence interval (CI) (0.32,1.55)] for prostate cancer and 1.06 [95% CI (0.67,1.67)] for BPH. After adjustment for body mass index, serum leptin levels were not significantly correlated with levels of any of the other hormones under study. Leptin levels are unlikely to affect the risk of either prostate cancer or BPH substantially.
 ...
PMID:Leptin in relation to prostate cancer and benign prostatic hyperplasia. 953 57

Understanding how the regulation of growth factor pathways alters during prostate cancer (PC) progression may enable researchers to develop targeted therapeutic strategies for advanced disease. PC progression involves the shifting of cells from androgen-dependent growth to an androgen-independent state, sometimes with the loss or mutation of the androgen receptors in PC cells. Both autocrine and paracrine pathways are up-regulated in androgen-independent tumors and may replace androgens as primary growth stimulatory factors in cancer progression. Our discussion focuses on growth factor families that maintain homeostasis between epithelial and stromal cells in the normal prostate and that undergo changes as PC progresses, often making stromal cells redundant. These growth factors include fibroblast growth factor, insulin-like growth factors, epidermal growth factor, transforming growth factor alpha, retinoic acid, vitamin D3, and the transforming growth factor beta families. We review their role in normal prostate development and in cancer progression, using evidence from clinical specimens and models of PC cell growth.
 ...
PMID:Growth factor involvement in progression of prostate cancer. 955 81

During the last decade there were extensive investigations in clinical and molecular andrology with emphasis on assisted reproduction, micromanipulation techniques of gametes, sperm/egg interaction, male contraception, diabetes mellitus, varicocele, andropause versus menopause, sexual dysfunction, associated hypertension/stress, prostatic carcinoma and molecular parameters of male reproduction. Sperm hyperactivation is a required step in capacitation sequence. Sperm motility is measured by videotape to evaluate the Straight Line Velocity (microm/s) (VSLI). Fertilization/embryonic development results from single sperm transfer (S-MIST) and multiple sperm transfer. Fertilization/embryo development is achieved by injection of immotile sperm into the perivitelline space. To assess sperm viability, a supravital stain suitable for use in combination with immunofluorescent assay, Hoeschst 33258, is used. The dye fluoresces with an intense blue when bound to DNA. To assess sperm plasma membrane integrity, a hypo-osmotic swelling test (HOST) is performed, using fluoresceinated D-mannose enriched albumin (FITC-DMA). The ability of sperm to swell under hypo-osmotic conditions indicates an intact membrane. A human protein, C-peptide, thought to be a useless byproduct of insulin may protect against devastating heart and nerve damage that diabetes causes. Human diabetics may benefit from the substance. Over 15 million Americans have diabetes, in which blood sugar levels rise out of control. There are two types of diabetics: Type I diabetics produce no insulin, the hormone that regulates blood sugar. Type II diabetics are unable to use their insulin properly. Diabetics are at great risk of heart disease and nerve damage, as arteries throughout the body leak and nerve-cell impulses fail. C-peptide is a byproduct of insulin production; it can be produced by the body or synthetically. Production of this protein is not induced by insulin, so diabetics who take insulin do not get C-peptide with it. Varicocele occurs unilaterally on the left side in 78% to 93% of men. Typically the presence of a varicocele is associated with an abnormal semen analysis (sperm density and morphology) and a decreased testicular volume on the affected side. Impaired sperm motility occurs in 89.5% of all varicocele patients. Varicocele ligation improves semen parameters in two thirds of patients. A few studies on andropause included sexual dysfunction, hormonal changes, medical/psychological correlates of impotence, ostenopenia/osteoporosis and bone loss; indices of bone remodeling, testosterone supplementation, androgen, negative feedback and hypothalamo-pituitary-testicular axis. Prostatic cancer is the second leading cause of cancer death for men between the ages of 60 and 80. Early detection involves a simple blood test for prostate specific antigen (PSA). Regular screening and early detection are essential. This is an important test because a high antigen count can be the only symptom. Since no screening is 100% accurate, physicians recommend both a PSA blood test and a physical examination. Although heredity plays a major role in whether a man will develop prostate cancer, men who lead healthy lives can dramatically reduce their chances of cancer: low-fat diet, eating plenty of fruits and vegetables and not smoking. Recent advances in molecular andrology include peptide hormone binding proteins; gonadotropin-releasing hormone (GnRH) agonists/antagonists analog; gonadotropins/their receptors; growth factors/reproduction; peptides as intratesticular regulators; molecular cloning of reproductive proteins/peptides. Gene cloning is applied for characterization/expression of genes coding. The interaction of gp120 with CD4 receptor plays a role in syncytium formation, apoptosis and CD4 cell deletion in human immunodeficiency virus (HIV) infection. The recombinant V3 peptide of fragment 307-330 of HIV-1 can induce sperm head agglutination. The generation process of react
 ...
PMID:Recent advances in clinical/molecular andrology. 958 57

Insulin-like growth factors I and II (IGF-I and -II) are potent mitogens for various cancers, including carcinoma of the prostate. In several experimental cancers, treatment with antagonists of growth hormone-releasing hormone (GH-RH) produces a reduction in IGF-I and -II, concomitant to inhibition of tumor growth. To investigate the mechanisms involved, we treated male nude mice bearing xenografts of DU-145 human androgen-independent prostate cancer for 8 weeks with potent GH-RH antagonist MZ-5-156 at a dose of 20 microg/animal s.c. twice a day. Tumor growth, serum and tumor levels of IGF-I and -II, and the mRNA expression of IGF-I and -II in tumors were evaluated. After 8 weeks of therapy, final volume and weight of DU-145 tumors in mice treated with MZ-5-156 were significantly (P < 0.01) decreased compared with controls, and serum IGF-I showed a significant reduction. Treatment of nude mice bearing DU-145 xenografts with MZ-5-156 also significantly (P < 0.01) diminished by 77% the levels of IGF-II in tumor tissue compared with controls, but did not affect the concentration of IGF-I. Reverse transcription-PCR analyses revealed a high expression of IGF-II mRNA in DU-145 tumors. Treatment with GH-RH antagonist MZ-5-156 decreased the expression of IGF-II mRNA by 58% (P < 0.01) as compared with controls. Our work suggests that GH-RH antagonist MZ-5-156 may inhibit the growth of DU-145 human androgen-independent prostate cancers through a reduction in the production and mRNA expression of IGF-II by the tumor tissue. These findings extend our observations on the mechanism of action of GH-RH antagonists and may explain how GH-RH antagonists inhibit tumor growth.
 ...
PMID:Growth hormone-releasing hormone antagonist MZ-5-156 inhibits growth of DU-145 human androgen-independent prostate carcinoma in nude mice and suppresses the levels and mRNA expression of insulin-like growth factor II in tumors. 967 70

Diazepam-binding inhibitor/acyl-CoA-binding protein (DBI/ACBP), a highly conserved 10-kDa polypeptide, has been implicated in various physiological processes including gamma-aminobutyric acid type A receptor binding, acyl-CoA binding and transport, steroidogenesis, and peptide hormone release. Both in LNCaP prostate cancer cells and 3T3-L1 preadipocytes, the expression of DBI/ACBP is stimulated under conditions that promote lipogenesis (treatment with androgens and insulin, respectively) and that involve the activation of sterol regulatory element-binding proteins (SREBPs). Accordingly, we investigated whether DBI/ACBP expression is under the direct control of SREBPs. Analysis of the human and rat DBI/ACBP promoter revealed the presence of a conserved sterol regulatory element (SRE)-like sequence. Gel shift analysis confirmed that this sequence is able to bind SREBPs. In support of the functionality of SREBP binding, coexpression of SREBP-1a with a DBI/ACBP promoter-reporter gene resulted in a 50-fold increase in transcriptional activity in LNCaP cells. Disruption of the SRE decreased basal expression and abolished SREBP-1a-induced transcriptional activation. In agreement with the requirement of a co-regulator for SREBP function, transcriptional activation by SREBP-1a overexpression was severely diminished when a neighboring NF-Y site was mutated. Cholesterol depletion or androgen treatment, conditions that activate SREBP function in LNCaP cells, led to an increase in DBI/ACBP mRNA expression and SRE-dependent transcriptional activation. These findings indicate that the promoter for DBI/ACBP contains a functional SRE that allows DBI/ACBP to be coregulated with other genes involved in lipid metabolism.
 ...
PMID:Identification of diazepam-binding Inhibitor/Acyl-CoA-binding protein as a sterol regulatory element-binding protein-responsive gene. 968 28

Troglitazone, a thiazolidinedione derivative, is a widely used antidiabetic drug that binds and activates peroxisome proliferator-activated receptor gamma (PPARgamma) and enhances insulin sensitivity. It induces differentiation of adipocytes, which highly express PPARgamma. We report that human prostate cancer cells expressed PPARgamma at prominent levels and normal prostate tissues had very low expression. Dose-response clonogenic assays of the PC-3 prostate cancer cell line with troglitazone showed an antiproliferative effect (ED50, 3 x 10(-7) M) and other PPARgamma ligands (BRL49653: ED50, 8 x 10(-8) M; 15-deoxy-delta12,14-prostaglandin J2: ED50, 2 x 10(-6) M; ciglitizone: ED50, not reached; indomethacin: ED50, not reached) showed similar effects. Combinations of troglitazone and a ligand specific for either retinoid X receptor or retinoic acid receptor did not show a synergistic effect. Pulse-exposure to troglitazone (10(-5) M) for different durations showed that 4 days of pulse-exposure to the agent irreversibly inhibited 50% clonal growth of PC-3 cells. Interestingly, PC-3 cells cultured with troglitazone (10(-5) M) showed dramatic morphological changes both by light and electron microscopy, suggesting that the cells became less malignant. Nevertheless, troglitazone did not affect either the cell cycle or several markers of differentiation. LNCaP cells constitutively produced prostate-specific antigen, and levels were markedly enhanced by all-trans-retinoic acid. Troglitazone (10(-5) M, 4 days) decreased by 50% the levels of prostate-specific antigen produced by these cells. In vivo treatment of PC-3 tumors growing in male BNX triple immunodeficient mice with oral troglitazone (500 mg/kg/day) produced significant inhibition of tumor growth (P = 0.01). The only objective side effect of troglitazone in mice was the elevation of serum transaminases. Short-term culture of four surgically obtained human prostate cancer tumors with troglitazone (10(-5) M, 4 days) produced marked and selective necrosis of the cancer cells (about 60%) but not the adjacent normal prostate cells. Taken together, these results suggest that troglitazone may be a useful therapeutic agent for the treatment of prostate cancer, especially in the setting of low disease burden.
 ...
PMID:Ligand for peroxisome proliferator-activated receptor gamma (troglitazone) has potent antitumor effect against human prostate cancer both in vitro and in vivo. 969 65


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>