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)

Progression of prostate cancer to androgen independence remains the primary obstacle to improved survival. The development of more effective treatments depends on our understanding of the molecular events associated with the hormone-refractory stage. We quantified, among 90 screened genes, the expression of 37 target genes, using real-time quantitative RT-PCR. Gene expression was studied in 13 samples of HPRC compared to 33 clinically localised cancers and normal prostate tissue. We identify 19 genes with significant differential expression in HRPC compared to localised prostate cancer. Genes with decreased expression included receptors for growth factors, MMR genes and the serine protease hepsin. Analysis of increased gene expression confirmed the importance of AR upregulation and highlighted genes not previously linked to HRPC, including enzymes involved in steroid synthesis and the antiapoptotic factor survivin. Progression of prostate cancer to the hormone-refractory state is associated with differential gene expression, which may prove useful for both understanding disease progression and the development of new therapeutic approaches.
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PMID:Differential expression of 37 selected genes in hormone-refractory prostate cancer using quantitative taqman real-time RT-PCR. 1554 16

We found that bone morphogenetic protein (BMP) 7, a member of the BMP family, was strikingly up-regulated during the development of primary prostatic adenocarcinoma in the conditional Pten deletion mouse model. To determine the relevance of this finding to human prostate cancer, we examined the expression of BMPs and BMP receptors (BMPR) as well as the responsiveness to recombinant human BMP7 in a series of human prostate tumor cell lines. All prostatic cell lines tested expressed variable levels of BMP2, BMP4, and BMP7 and at least two of each type I and II BMPRs. In all cases, BMP7 induced Smad phosphorylation in a dose-dependent manner, with Smad5 activation clearly demonstrable. However, the biological responses to BMP7 were cell type specific. BPH-1, a cell line representing benign prostatic epithelial hyperplasia, was growth arrested at G1. In the bone metastasis-derived PC-3 prostate cancer cells, BMP7 induced epithelial-mesenchymal transdifferentiation with classic changes in morphology, motility, invasiveness, and molecular markers. Finally, BMP7 inhibited serum starvation-induced apoptosis in the LNCaP prostate cancer cell line and more remarkably in its bone metastatic variant C4-2B line. Each of the cell lines influenced by BMP7 was also responsive to BMP2 in a corresponding manner. The antiapoptotic activity of BMP7 in the LNCaP and C4-2B cell lines was not associated with a significant alteration in the levels of the proapoptotic protein Bax or the antiapoptotic proteins Bcl-2, Bcl-xl, and X-linked inhibitor of apoptosis. However, in C4-2B cells but not in LNCaP cells, a starvation-induced decrease in the level of survivin was counteracted by BMP7. Taken together, these findings suggest that BMPs are able to modulate the biological behavior of prostate tumor cells in diverse and cell type-specific manner and point to certain mechanisms by which these secreted signaling molecules may contribute to prostate cancer growth and metastasis.
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PMID:Diverse biological effect and Smad signaling of bone morphogenetic protein 7 in prostate tumor cells. 1599 52

Indole-3-carbinol (I3C) is produced by members of the family Cruciferae, and particularly members of the genus Brassica (e.g., cabbage, radishes, cauliflower, broccoli, Brussels sprouts, and daikon). Under acidic conditions, 13C is converted to a series of oligomeric products (among which 3,3'-diindolylmethane is a major component) thought to be responsible for its biological effects in vivo. In vitro, 13C has been shown to suppress the proliferation of various tumor cells including breast cancer, prostate cancer, endometrial cancer, colon cancer, and leukemic cells; induce G1/S arrest of the cell cycle, and induce apoptosis. The cell cycle arrest involves downregulation of cyclin D1, cyclin E, cyclin- dependent kinase (CDK)2, CDK4, and CDK6 and upregulation of p15, p21, and p27. Apoptosis by I3C involves downregulation antiapoptotic gene products, including Bcl-2, Bcl-xL, survivin, inhibitor-of-apoptosis protein (IAP), X chromosome-linked IAP (XIAP), and Fas-associated death domain protein-like interleukin-1-beta-converting enzyme inhibitory protein (FLIP); upregulation of proapoptotic protein Bax; release of micochondrial cytochrome C; and activation of caspase-9 and caspase-3. This agent inhibits the activation of various transcription factors including nuclear factor-kappaB, SP1, estrogen receptor, androgen receptor and nuclear factor-E2-related factor 2 (Nrf2). This indole potentiates the effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) through induction of death receptors and synergises with chemotherapeutic agents through downregulation of P-glycoprotein (P-gp). In vivo, I3C was found to be a potent chemopreventive agent for hormonal-dependent cancers such as breast and cervical cancer. These effects are mediated through its ability to induce apoptosis, inhibit DNA-carcinogen adduct formation, and suppress free-radical production, stimulate 2-hydroxylation of estradiol, inhibit invasion and angiogenesis. Numerous studies have indicated that I3C also has a strong hepatoprotective activity against various carcinogens. Initial clinical trials in women have shown that I3C is a promising agent against breast and cervical cancers.
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PMID:Molecular targets and anticancer potential of indole-3-carbinol and its derivatives. 1608 11

Acquired multi-drug resistance remains a major obstacle in the management of prostate cancer. The objective of this study was to examine whether chemoresistance could be due in part to the expression of the inhibitors of apoptosis proteins (IAPs). We established cisplatin-resistant LNCaP sublines. We examined the effects of cisplatin on cell growth and apoptosis in LNCaP cells and LNCaP sublines by 2-(4-lodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-1) assay and Hoechst 33258 staining, and analyzed cross-resistance to adriamycin, 5-fluorouracil, taxol, taxotere, and etoposide. In addition, the expression of IAP-1, IAP-2, X-linked IAP (XIAP), neuronal apoptosis inhibitory protein, and survivin was investigated by immunoblot analysis in LNCaP sublines. Although the growth rates were reduced in a dose-dependent manner by cisplatin in LNCaP sublines, the anti-proliferative effects of cisplatin were significantly decreased in LNCaP sublines compared to LNCaP cells. Cisplatin-resistant sublines, LNCaP/C1, LNCaP/ C2, and LNCaP/C3 cells, were 6.3-, 9.1-, and 22.3-fold more resistant to cisplatin than LNCaP cells, respectively, and this resistance was paralleled with reduced induction of apoptosis. LNCaP/C3 cells showed cross-resistance to adriamycin, 5-fluorouracil, and etoposide whereas those cells exhibited no or only weak cross-resistance against taxol and taxotere. With the exception of survivin, all the IAPs were identified in LNCaP cells by immunoblot analysis. Interestingly, the expression of IAP-2, XIAP, and survivin gradually increased with the extent of cisplatin-resistance. Altered expression of IAP-2, XIAP, and survivin was involved in these phenotypes of cisplatin-resistant LNCaP sublines. IAPs may make an important contribution to the resistance to the apoptotic effect of cisplatin in prostate cancer.
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PMID:Expression of the inhibitors of apoptosis proteins in cisplatin-resistant prostate cancer cells. 1614 63

Angiogenesis is a primary disease target in ocular retinopathy and a secondary target in numerous other angiogenic diseases such as cancer, rheumatoid arthritis and psoriasis. Clinical trials using antiangiogenic antisense oligonucleotides (aso's) for the treatment of ocular disorders or cancer are well advanced. Clusterin aso's are currently under investigation for the treatment of prostate cancer. We have investigated the antiangiogenic properties of clusterin aso's using a capillary cell (HUVEC) viability assay. In this study we included aso's to known apoptosis modulators (bcl-2, bcl-xl and survivin) which were previously identified in HUVEC's. We have also studied the effect of clusterin aso's on angiogenesis using an in vitro, matrigel assay and on HUVEC apoptosis using an ELISA DNA fragmentation assay. Clusterin, bcl-2, bcl-xl and survivin aso's were all found to inhibit HUVEC growth. The apoptosis-inducing drugs paclitaxel, camptothecin and doxorubicin were also found to inhibit HUVEC proliferation. Combinations of aso's with these drugs demonstrated a minor additive but not synergistic inhibitory effect on HUVEC proliferation. Clusterin aso's were found to strongly inhibit angiogenesis and induce high levels of apoptosis in HUVECs. In cancer cells the prosurvival protein clusterin may protect the cells from apoptosis-inducing agents so that the clusterin aso's may act as chemosensitization agents. These data demonstrate a strong antiangiogenic action of clusterin aso's, that is not necessarily related to any chemosensitization effect of this agent.
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PMID:The inhibition of angiogenesis by antisense oligonucleotides to clusterin. 1630 31

Survivin is an antiapoptotic gene, which is overexpressed in most human tumors and involved in mitotic checkpoint control. Recent evidence points to an essential role for heat shock protein 90 (Hsp90) in survivin function regulation. Although the survivin-Hsp90 association may promote tumor cell proliferation, it may also suggest new opportunities for the design of novel anticancer approaches. We evaluated the effect of small interfering RNA (siRNA)-mediated inhibition of survivin on the proliferative potential of prostate cancer cells and their sensitivity to the Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG). Human androgen-independent prostate cancer cell lines (DU145 and PC-3) were transfected with four 21-mer double-stranded siRNAs (100 nmol/L) directed against different portions of survivin mRNA. After transfection, cells were collected and analyzed for survivin mRNA and protein expression, cell proliferation rate, ability to undergo apoptosis, and sensitivity to 17-AAG. Transfection of prostate cancer cells with siRNAs induced a variable extent of inhibition of survivin mRNA expression (39-60% compared with controls), which was paralleled by a 38% to 75% reduction in survivin protein abundance. The three siRNAs able to induce the greatest inhibition of survivin expression also significantly reduced cell proliferation and enhanced the rate of apoptosis, with a concomitant increase in caspase-9 activity. Sequential treatment with siRNA and 17-AAG induced supra-additive antiproliferative effects in all cell lines, with an enhanced caspase-9-dependent apoptotic response. These findings suggest that combined strategies aimed at interfering with the survivin-Hsp90 connection may provide novel approaches for treatment of androgen-independent prostate cancer.
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PMID:Silencing of survivin gene by small interfering RNAs produces supra-additive growth suppression in combination with 17-allylamino-17-demethoxygeldanamycin in human prostate cancer cells. 1643 77

Prostate epithelial cell growth is dependent on the presence of androgens, and transition of prostate cancer to an androgen-independent phenotype results in a highly aggressive, currently incurable cancer. We have developed a new preclinical model of androgen-independent prostate cancer derived from the VCaP prostate cancer epithelial cell line. VCaP cells were subcutaneously implanted and serially passaged in castrated male severe combined immunodeficient mice. Androgen independence was confirmed by WST-1 (a tetrazolium salt) cell proliferation assay in the absence or presence of dihydrotesterone (1-100 nM). VCaP androgen-sensitive cells responded dose dependently to dihydrotesterone, whereas VCaP androgen-independent cells did not alter their proliferation in response to dihydrotesterone. Gene expression of androgen receptor, B-cell lymphoma-2, prostate cancer antigen 3, prostate acid phosphatase, 6 transmembrane epithelial antigen of the prostate, and survivin was determined by polymerase chain reaction amplification. B-cell lymphoma-2 expression was up regulated in the VCaP androgen-independent lines compared to the VCaP androgen-sensitive, suggesting a possible mechanism of androgen independence. Furthermore, tumor-associated angiogenesis was assessed by immunofluorescence confocal microscopy of CD31. VCaP androgen-independent tumors showed enhanced angiogenesis compared to VCaP androgen-sensitive tumors. These results illustrate the development of a novel model of prostate cancer androgen independence and provide a new system to study angiogenesis and the transition to androgen independence.
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PMID:Development of the VCaP androgen-independent model of prostate cancer. 1652 Feb 80

We reported earlier that exposure to exogenous bone morphogenetic protein 7 (BMP7) could strongly inhibit serum starvation-induced apoptosis to C4-2B cell line, a variant of the LNCaP human prostate cancer cell line with propensity for bone metastasis. Whereas serum starvation suppressed the expression of survivin, a member of the inhibitor of apoptosis protein family, its expression was sustained in the presence of BMP7. In this study, we present evidence that BMP7 exposure up-regulated survivin promoter activity, an effect that was associated with activation of Smad, and could be repressed by dominant-negative Smad5. Additionally, serum starvation-induced suppression of c-jun NH2-terminal kinase (JNK) activity in C4-2B cells could be mostly restored by BMP7, and a JNK inhibitor could counteract the antiapoptotic effect of BMP7, without a significant effect on the level of survivin expression. Thus, we identified JNK pathway as another signaling mode for the antiapoptotic function of BMP7. To test the effect of endogenous up-regulation of BMP7, we genetically modulated the C4-2B cell line to overexpress BMP7 protein. Not only was this altered cell line resistant to serum starvation-induced apoptosis but it also exhibited patterns of Smad activation, survivin up-regulation, and JNK activation similar to those of the parental C4-2B cells exposed to exogenous BMP7. Consistent with these in vitro findings of BMP7 action, we acquired correlative results of Smad activation, survivin expression, and JNK activation in the progression of prostate cancer in the conditional Pten deletion mouse model, in which we first obtained the evidence of BMP7 overexpression.
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PMID:Bone morphogenetic protein 7 protects prostate cancer cells from stress-induced apoptosis via both Smad and c-Jun NH2-terminal kinase pathways. 1661 53

Clinical trials have shown that chemotherapy with docetaxel combined with prednisone can improve survival of patients with androgen-independent prostate cancer. It is likely that the combination of docetaxel with other novel chemotherapeutic agents would also improve the survival of androgen-independent prostate cancer patients. We investigated whether the combination of docetaxel and flavopiridol, a broad cyclin-dependent kinase inhibitor, can increase apoptotic cell death in prostate cancer cells. Treatment of DU 145 prostate cancer cells with 500 nmol/L flavopiridol and 10 nmol/L docetaxel inhibited apoptosis probably because of their opposing effects on cyclin B1-dependent kinase activity. In contrast, when LNCaP prostate cancer cells were treated with flavopiridol for 24 hours followed by docetaxel for another 24 hours (FD), there was a maximal induction of apoptosis. However, there was greater induction of apoptosis in DU 145 cells when docetaxel was followed by flavopiridol or docetaxel. These findings indicate a heterogeneous response depending on the type of prostate cancer cell. Substantial decreases in X-linked inhibitor of apoptosis (XIAP) protein but not survivin, both being members of the IAP family, were required for FD enhanced apoptosis in LNCaP cells. Androgen ablation in androgen-independent LNCaP cells increased activated AKT and chemoresistance to apoptosis after treatment with FD. The proteasome inhibitor MG-132 blocked FD-mediated reduction of XIAP and AKT and antagonized apoptosis, suggesting that the activation of the proteasome pathway is one of the mechanisms involved. Overall, our data suggest that the docetaxel and flavopiridol combination requires a maximal effect on cyclin B1-dependent kinase activity and a reduction of XIAP and AKT prosurvival proteins for augmentation of apoptosis in LNCaP cells.
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PMID:Sequential combination of flavopiridol and docetaxel reduces the levels of X-linked inhibitor of apoptosis and AKT proteins and stimulates apoptosis in human LNCaP prostate cancer cells. 1673 54

Despite local and systemic therapies, the National Cancer Institute estimates that prostate cancer will cause over 30,000 deaths in 2006. This suggests that additional therapeutic approaches are needed. The chicken anemia viral protein Apoptin causes tumor-selective apoptosis in human tumor lines independent of p53 and Bcl-2 status. Tet-regulated expression of Apoptin from an adenoviral vector showed cytotoxicity in DU145, PC-3, and LNCaP tumor cells regardless of expression of p53, Bcl-2, Bcl-xL, Bax, survivin, FLIP(S), XIAP, or CIAP. Apoptin expression caused an increase in the tumor suppressor lipid ceramide, which regulates the cellular stress response. Interestingly, 10 of 15 primary prostate cancers examined by Western blotting overexpressed acid ceramidase (AC), suggesting that ceramide deacylation might serve to negate elevated levels of ceramide, creating a more antiapoptotic phenotype. This was confirmed in AC-overexpressing cells in which we observed decreased sensitivity to apoptosis following treatment with Apoptin. Addition of the AC inhibitor LCL204, in combination with Apoptin, augmented cell killing. This effect was also demonstrated in vivo in that Apoptin and LCL204 cotreatment significantly reduced tumor growth in DU145 xenografts (P<0.05). Taken together, our data demonstrated that Apoptin is a promising therapeutic agent for prostate cancer and that its function is improved when combined with acid ceramidase inhibitors.
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PMID:Modulation of ceramide metabolism enhances viral protein apoptin's cytotoxicity in prostate cancer. 1716 68


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