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)

Breast cancer is the most common malignancy in women worldwide and pharmaceutical agents have therapeutic and preventive effects in breast cancer. The human epidermal growth factor receptor 2/neu is one of the most important oncogenes in human breast cancer. Prepubertal exposure to endogenous estradiol and a phytoestrogen, genistein (Gen), has been shown to reduce future breast cancer risk. Gen downregulates tyrosine kinase regulated protein expression and reduces prostate cancer. In this study, the effects of prepubertal exposure to Gen on rat mammary carcinogenesis and the erbB2/Akt signal pathway were investigated. Prepubertal female Sprague-Dawley rats were daily exposed to Gen at 125 mg/kg (Gen-1) and 500 mg/kg (Gen-5) from postnatal days 22-28. Subsequently, the rats were given a single dose of 100 mg/kg 7.12-dimethylbenz [a] anthracene on postnatal day 42 to induce mammary tumor. The mRNA expression of erbB2 and amplified in breast cancer 1 (AIB1) was detected by reverse transcription-polymerase chain reaction. The protein levels of proliferating cell nuclear antigen (PCNA), erbB2, phosphotyrosine protein, Akt, and p-Akt were detected by immunohistochemistry and Western blotting. The activity of protein tyrosine kinase (PTK) was detected by liquid scintillation counting. The percentage of rats with mammary tumors in breast cancer model (BCM), Gen-1, and Gen-5 was 71.43, 52.38, and 33.34%, respectively. The incidence of 7.12-dimethylbenz [a] anthracene-induced mammary tumors significantly decreased in Gen-5 compared with that in BCM. The mRNA levels of AIB1 and erbB2 and the protein levels of erbB2, p-Akt, and PCNA protein expression were downregulated for a long time in the mammary tumors in Gen-5 groups. The activity of PTK was also decreased for a long time. However, the total Akt protein expression did not change significantly among BCM, Gen-1, and Gen-5. Prepubertal exposure of Sprague-Dawley female rats to 500 mg/kg Gen can reduce later breast cancer risk and its protective effect is associated with persistent downregulation of the expression of erbB2, p-Akt, AIB1, and PCNA and with low PTK activity in the mammary tumor. Our results suggest that erbB2/Akt signaling plays a role in tumor formation and targeting erbB2/Akt signaling with prepubertal exposure to Gen may provide greater efficacy to the current therapies used to treat tumors.
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PMID:Prepubertal genistein exposure affects erbB2/Akt signal and reduces rat mammary tumorigenesis. 2005 71

We investigated the antiproliferative activity of (-)-gossypol on the human prostate cancer cell line PC3 in vitro and in vivo to elucidate its potential molecular mechanisms. Cell growth and viability were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell apoptosis was detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) and electron microscopy. Expression of proliferating cell nuclear antigen (PCNA), Bcl-2, CD31, caspase-3 and caspase-8 in tumour tissue was determined by immunohistochemistry. The drug concentration that yielded 50% cell inhibition (IC(50) value) was 4.74 microg mL(-1). In the PC-3 tumour xenograft study, (-)-gossypol (> 5 mg kg(-1)) given once a day for 7 days significantly inhibited tumour growth in a dose-dependent manner. Immunohistochemical analysis revealed that (-)-gossypol enhanced caspase-3 and caspase-8 expression and decreased the expression of PCNA, Bcl-2 and CD31 in tumour tissues. It suggested that cell apoptosis and inhibition of angiogenesis might contribute to the anticancer action of (-)-gossypol.
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PMID:Inhibition of proliferation of prostate cancer cell line, PC-3, in vitro and in vivo using (-)-gossypol. 2008 72

Prostate cancer (PCA) is the most common invasive malignancy and the second leading cause of cancer-related death in males. The present study investigated the effects of fangchinoline (Fan), an important compound in Stephania Tetradra S. Moore (Fenfangji) with pain-relieving, blood pressure-depressing, and antibiotic activities, on human PCA. It was found that Fan inhibited human prostate cancer cell lines (PC3) cell proliferation in a dose- and time-dependent manner. Studies of cell-cycle progression showed that the anti-proliferative effect of Fan was associated with an increase in the G1/S phase of PC3 cells. Western blot results indicated that Fan-induced G1/S phase arrest was mediated through inhibition of cyclin-regulated signaling pathways. Fan induced p27 expression and inhibited cyclin D and proliferating cell nuclear antigen (PCNA) expression in PC3 cells. Increased exposure time to Fan caused apoptosis of PC3 cells, which was associated with up-regulation of pro-apoptotic proteins Bax and caspase 3, and down-regulation of anti-apoptotic protein Bcl-2. Furthermore, Fan had anti-tumorigenic activity in vivo, including reduction of tumor volume and pro-apoptotic and anti-proliferative effects in a PC3 nude mouse xenograft. Taking all this together, it can be concluded that Fan is an effective anti-proliferative agent that modulates cell growth regulators in prostate cancer cells.
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PMID:Fangchinoline induced G1/S arrest by modulating expression of p27, PCNA, and cyclin D in human prostate carcinoma cancer PC3 cells and tumor xenograft. 2020 55

Previous studies have suggested that 1,25 dihydroxyvitamin D(3) (1,25(OH)2D3) induces cell cycle arrest and/or apoptosis in prostate cancer cells in vitro, suggesting that vitamin D may be a useful adjuvant therapy for prostate cancer and a chemopreventive agent. Most epidemiological data however shows a weak link between serum 25(OH)D3 and risk of prostate cancer. To explore this dichotomy we have compared tumor progression in the LPB-Tag model of prostate in VDR knock out (VDRKO) and wild type (VDRWT) mice. On the C57BL/6 background LPB-Tag tumors progress significantly more rapidly in the VDRKO mice. VDRKO tumors show significantly higher levels of cell proliferation than VDRWT tumors. In mice supplemented with testosterone to restore the serum levels to the normal range, these differences in tumor progression, and proliferation are abrogated, suggesting that there is considerable cross-talk between the androgen receptor (AR) and the vitamin D axis which is reflected in significant changes in steady state mRNA levels of the AR, PCNA, cdk2 survivin and IGFR1 and 2 genes. These alterations may explain the differences between the in vitro data and the epidemiological studies.
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PMID:Tumor progression in the LPB-Tag transgenic model of prostate cancer is altered by vitamin D receptor and serum testosterone status. 2034 77

The neuropeptide growth hormone-releasing hormone (GHRH) is secreted by the hypothalamus and upon the binding to the receptors for GHRH on the pituitary gland regulates the release of growth hormone. Substantial evidence indicate that GHRH, in addition to its physiological role as a hypophysiotrophic hormone, acts as a growth factor in diverse tissues and various tumors. In this study we evaluated the expression of GHRH and its receptors in a variety of cancer and non-cancerous cell lines and studied the effect of GHRH antagonists and agonists on the proliferative cell nuclear antigen, cyclin D3, tumor suppressor protein p53 and carboxyl-terminal-binding protein (CtBP1). Our findings show that GHRH agonist JI-38 downregulates wt-p53 and upregulates the expression of PCNA. GHRH also upregulates CtBP1 protein expression and its antagonists downregulate it in LNCaP prostate cancer cells. Furthermore, GHRH and its agonist JI-38 upregulates the expression of the proliferative markers cyclin D3 and PCNA in A549 non-small cell lung carcinoma and GHRH antagonist MZ-5-156 downregulates it. Our results support previous findings on the mitogenic role of GHRH in cancers and underline the importance of GHRH antagonists as anticancer agents.
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PMID:Effects of growth hormone-releasing hormone and its agonistic and antagonistic analogs in cancer and non-cancerous cell lines. 2037 4

gamma-Tocotrienol (gammaT3) is known to selectively kill prostate cancer (PCa) cells and to sensitize the cells to docetaxel (DTX)-induced apoptosis. In the present study, the pharmacokinetics of gammaT3 and the in vivo cytotoxic response of androgen-independent prostate cancer (AIPCa) tumor following gammaT3 treatment were investigated. Here, we investigated these antitumor effects for PCa tumors in vivo. The pharmacokinetic and tissue distribution of gammaT3 after exogenous gammaT3 supplementation were examined. Meanwhile, the response of the tumor to gammaT3 alone or in combination with DTX were studied by real-time in vivo bioluminescent imaging and by examination of biomarkers associated with cell proliferation and apoptosis. After intraperitoneal injection, gammaT3 rapidly disappeared from the serum and was selectively deposited in the AIPCa tumor cells. Administration of gammaT3 alone for 2 weeks resulted in a significant shrinkage of the AIPCa tumors. Meanwhile, further inhibition of the AIPCa tumor growth was achieved by combined treatment of gammaT3 and DTX (p < 0.002). The in vivo cytotoxic antitumor effects induced by gammaT3 seem to be associated with a decrease in expression of cell proliferation markers (proliferating cell nuclear antigen, Ki-67 and Id1) and an increase in the rate of cancer cell apoptosis [cleaved caspase 3 and poly(ADP-ribose) polymerase]. Additionally, the combined agents may be more effective at suppressing the invasiveness of AIPCa. Overall, our results indicate that gammaT3, either alone or in combination with DTX, may provide a treatment strategy that can improve therapeutic efficacy against AIPCa while reducing the toxicity often seen in patients treated with DTX.
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PMID:In vivo evidence of gamma-tocotrienol as a chemosensitizer in the treatment of hormone-refractory prostate cancer. 2037 35

Cellular prostatic acid phosphatase (cPAcP), an authentic tyrosine phosphatase, is proposed to function as a negative growth regulator of prostate cancer (PCa) cells in part through its dephosphorylation of ErbB-2. Nevertheless, the direct interaction between cPAcP and ErbB-2 has not been shown nor the specific dephosphorylation site of ErbB-2 by cPAcP. In this report, our data show that the phosphorylation level of ErbB-2 primarily at Tyr(1221/2) correlates with the growth rate of both LNCaP and MDA PCa2b human PCa cells. Further, cPAcP reciprocally co-immunoprecipitated with ErbB-2 in a non-permissive growth condition. Expression of wild type cPAcP, but not inactive mutant, by cDNA in cPAcP-null LNCaP C-81 cells results in decreased tyrosine phosphorylation of ErbB-2 including Tyr(1221/2). Concurrently, Tyr(317) phosphorylation of p52(Shc), proliferating cell nuclear antigen expression, and cell growth are decreased in these cells. Conversely, decreased cPAcP expression by short hairpin RNA in LNCaP C-33 cells was associated with elevated phosphorylation of ErbB-2 initially at Tyr(1221/2). Its downstream p52(Shc), ERK1/2, Akt, Src, STAT-3, and STAT-5 were activated, and cell proliferation, proliferating cell nuclear antigen, and cyclin D1 expression were increased. Stable subclones of C-33 cells by small interfering PAcP had elevated Tyr(1221/2) phosphorylation of ErbB-2 and exhibited androgen-independent growth and increased tumorigenicity in xenograft female animals. In summary, our data together indicate that in prostate epithelia, cPAcP interacts with and dephosphorylates ErbB-2 primarily at Tyr(1221/2) and hence blocks downstream signaling, leading to reduced cell growth. In PCa cells, decreased cPAcP expression is associated with androgen-independent cell proliferation and tumorigenicity as seen in advanced hormone-refractory prostate carcinomas.
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PMID:Human prostatic acid phosphatase, an authentic tyrosine phosphatase, dephosphorylates ErbB-2 and regulates prostate cancer cell growth. 2049 73

cRNA microarray and real-time PCR (qPCR) studies from our lab identified five Cell Cycle Pathway (CCP) genes (CCNA2, CCNE2, CDC25A, CDKN1B, and PLK-1) as targets for luteolin in PC-3 prostate cancer cells [Shoulars et al., J. Steroid Biochem. Mol. Biol. 118 (2010) 41-50]. In this paper, Ingenuity Pathway Analysis of the microarray data identified 7 luteolin-regulated genes (EGFR, c-Fos, SOS, GRB2, JNK1, MKK4 and RasGAP) in the Epidermal Growth Factor Signaling Pathway (EGFSP) potentially involved in luteolin regulation of CCP genes and cell proliferation. To address these possibilities, we compared the response profiles (RNA and protein) of these EGFSP and CCP genes to luteolin and gefitinib by real-time PCR (qPCR) and Western blot analyses. Luteolin and gefitinib are known antagonists of EGFR-associated tyrosine protein kinase. Thus, the response profiles of EGFR regulated EGFSP or CCP genes should be very similar if genes in both pathways are controlled through this common mechanism of action. Treatment of PC-3 cell with luteolin for 24h caused a 4-fold stimulation of c-Fos gene expression, significant inhibition (p<0.001) of the CCP genes and G2/M arrest. Treatment of PC-3 cells with gefitinib also inhibited most of the CCP genes in a fashion similar to that of luteolin, however, the EGFR antagonist inhibited c-Fos gene expression, stimulated CDKN1B (p27) and arrested the cells in G0/G1. Thus, although the response patterns of most of the CCP genes to luteolin or gefitinib were similar, the effects of the two compounds on EGFSP gene expression and cell cycle arrest were clearly different. Combination studies revealed that the response of EGFSP genes to luteolin was not affected by gefitinib, even though the two compounds were additive with respect to their abilities to inhibit CCNA2, CCNE2, CDC25A and PCNA. These findings suggest that luteolin and gefitinib regulate CCP gene expression through a common mechanism involving EGFR-associated tyrosine kinase. Conversely, luteolin regulates PC-3 cell proliferation through an EGFR-tyrosine kinase independent mechanism(s), likely involving the epigenetic control of gene EGFSP gene expression through histone H4 binding interactions resulting in the upregulation of c-Fos and p21 gene expression.
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PMID:Luteolin and gefitinib regulation of EGF signaling pathway and cell cycle pathway genes in PC-3 human prostate cancer cells. 2055 90

Akt is an important oncoprotein, and data suggest a critical role for nuclear Akt in cancer development. We have previously described a rapid (3-5 min) and P2X7-dependent depletion of nuclear phosphorylated Akt (pAkt) and effects on downstream targets, and here we studied mechanisms behind the pAkt depletion. We show that cholesterol-lowering drugs, statins, or extracellular ATP, induced a complex and coordinated response in insulin-stimulated A549 cells leading to depletion of nuclear pAkt. It involved protein/lipid phosphatases PTEN, pleckstrin homology domain leucine-rich repeat phosphatase (PHLPP1 and -2), protein phosphatase 2A (PP2A), and calcineurin. We employed immunocytology, immunoprecipitation, and proximity ligation assay techniques and show that PHLPP and calcineurin translocated to the nucleus and formed complexes with Akt within 3 min. Also PTEN translocated to the nucleus and then co-localized with pAkt close to the nuclear membrane. An inhibitor of the scaffolding immunophilin FK506-binding protein 51 (FKBP51) and calcineurin, FK506, prevented depletion of nuclear pAkt. Furthermore, okadaic acid, an inhibitor of PP2A, prevented the nuclear pAkt depletion. Chemical inhibition and siRNA indicated that PHLPP, PP2A, and PTEN were required for a robust depletion of nuclear pAkt, and in prostate cancer cells lacking PTEN, transfection of PTEN restored the statin-induced pAkt depletion. The activation of protein and lipid phosphatases was paralleled by a rapid proliferating cell nuclear antigen (PCNA) translocation to the nucleus, a PCNA-p21(cip1) complex formation, and cyclin D1 degradation. We conclude that these effects reflect a signaling pathway for rapid depletion of pAkt that may stop the cell cycle.
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PMID:Purinergic receptor-mediated rapid depletion of nuclear phosphorylated Akt depends on pleckstrin homology domain leucine-rich repeat phosphatase, calcineurin, protein phosphatase 2A, and PTEN phosphatases. 2060 78

Overexpression of helix-loop-helix protein-Id1 in prostate cancer correlates with tumor differentiation, and may play a key role in the development of prostate cancer. Hence, we inactivated the Id1 gene in prostate cancer cells in vitro and in vivo to determine whether the Id1 gene has therapeutic potential in the treatment of prostate cancer. A modified small interfering RNA (siRNA) was used to inactivate the Id1 gene in androgen-independent prostate cancer cell line PC3 and its xenografts in nude mice. Downregulation of Id1 by siRNA was confirmed by real-time PCR. The changes of cell viability, apoptosis and senescence rate in PC3 were individually detected. The mRNA and protein expression of Id1, PCNA and MMP2 in xenografted tumors was further individually assayed by real-time PCR and immunohistochemistry. The mRNA and protein expression of Id1 were obviously inhibited by the siRNA strategy in PC3 cells and their xenografts (P<0.01). The cell viability of PC3 was suppressed obviously (P<0.01); meanwhile, the apoptosis and senescence rates of PC3 were significantly increased by siRNA (P<0.01). Moreover, tumor growth was inhibited by the gene silencing of Id1. Two genes involved in proliferation (PCNA) and tumor invasion (MMP2) were found significantly decreased by siRNA in PC3 xenografts (P<0.01). Our results show that inactivation of Id1 can suppress cell proliferation, induce apoptosis and senescence in PC3. Silencing of the Id1 gene has an in-vivo preventive effect against the development of prostate cancer in a mouse model.
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PMID:Downregulation of Id1 by small interfering RNA in prostate cancer PC3 cells in vivo and in vitro. 2088 2


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