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)

Novel palliative strategies for patients with androgen-independent prostate cancer (AIPC) include targeting the epidermal growth factor receptor (EGFR) family. The aim of the present study was to investigate intrapatient changes of EGFRs during the development of AIPC. In total, 106 symptomatic AIPC patients were identified in whom prostatic biopsies (adenocarcinoma) were available both before the start of androgen deprivation (PRTR biopsy) and after the development of AIPC (AIPC biopsy). All four known subgroups of the EGFR family were determined by immunohistochemistry (IHC): c-erbB-1 (EGFR), c-erbB-2 (HER2/neu), c-erbB-3 (HER3) and c-erbB-4 (HER4). Moderate to strong membrane-specific staining was recorded semiquantitatively (<10% vs >/=10%=IHC stained tumour cells: 'negative' vs 'positive' staining). The medical records were reviewed for clinical variables. During the development of AIPC, intrapatient changes occurred in two opposite directions for each of the four EGFRs: negativity changed to positivity, and vice versa, statistically significant only for the increase of c-erbB-1 expression (P=0.001). The c-erbB-2 expression in the AIPC biopsy was associated with a significantly shorter survival from the time of the AIPC biopsy (P=0.029). Our results support ongoing therapeutic attempts of EGFR inhibition in subgroups of patients with prostate cancer. Further research is needed to understand the function of EGFRs in this malignancy.
 ...
PMID:Expression of the epidermal growth factor receptor family in prostate carcinoma before and during androgen-independence. 1473 92

We report the case of an 82-year-old male patient with a > 8-year history of prostate cancer (PrCa), who developed breast adenocarcinoma (BrCa) (Ki-67+ and negative for ER, PR, PSA and HER2/neu) after prolonged (approximately 7-year) anti-androgen (flutamide) monotherapy for locally advanced PrCa. Biochemical and molecular analyses showed hyperestrogenemia (serum estradiol = 266 pg/ml, with normal range < 74 pg/ml), germline BRCA-1 mutation (T to C at nucleotide 3232, in exon 11, causing Glu to Gly change at codon 1038) and chromosome 9 inversion (karyotype of 46,XY with inv(9) (p11q21)). Following bilateral mastectomy without adjuvant systemic therapy, the patient has been disease-free (from both BrCa and PrCa) for > 3 years. In contrast to LHRH-based hormonal therapies for PrCa, anti-androgen monotherapy causes hyper-estrogenemia due to the suppressed negative feedback loop of androgens on LHRH and LH production, stimulation of testicular androgen production and their intracrine transformation to estrogens in peripheral target tissues. In this case report, the hyperestrogenemia may have further increased the BrCa risk in a patient with other risk factors (BRCA-1 mutation and chromosome 9 inversion, which has been previously shown to impinge upon testicular function and intracrine balance of androgens vs. estrogens). This case report illustrates that PrCa patients receiving anti-androgen monotherapy may be at risk of BrCa, in the event of the concomitant presence of other genetically-determined predisposing factors, and indicates the importance of exercising caution against indiscriminate and prolonged use of anti-androgen monotherapy in patients with risk factors for male BrCa.
 ...
PMID:Male breast adenocarcinoma in a prostate cancer patient following prolonged anti-androgen monotherapy. 1515 26

HER2/neu is a proto-oncogene and a member of the epidermal growth factor receptor family of proteins that is overexpressed in numerous types of human cancer. We are currently conducting clinical trials with the HER2/neu E75 peptide vaccine in breast and prostate cancer patients. We have evaluated the use of HLA-A2 dimer molecule for the immunological monitoring of cancer patients receiving the E75 peptide vaccine. Peripheral blood samples from patients receiving the vaccine were stained with HLA-A2 dimers containing the vaccine peptide E75 or control peptides and analyzed by flow cytometry. We compared the HLA-A2 dimer assay to standard methods of immunologic monitoring (IFN-gamma release, lymphocyte proliferation, and cytotoxicity). The HLA-A2 dimer assay was also compared with the HLA-A2 tetramer assay. E75 peptide-specific CD8 T cells were detected directly in the peripheral blood of patients by staining with E75-HLA-A2 dimers and CD8 antibodies. T cell cultures generated by repeated stimulations using E75 peptide-pulsed dendritic cells showed increased staining with E75-peptide loaded HLA-A2 dimers. Simultaneously analysis by the dimer assay and standard immunologic assays demonstrated that the dimer-staining assay correlated well with these methods of immunologic monitoring. A direct comparison using E75-specific HLA-A2 tetramers and HLA-A2 dimers for the detection of E75-specific CD8 T cells in peripheral blood showed comparable results with the two assays. Our findings indicate that the HLA-A2 dimer is a powerful new tool for directly quantifying and monitoring immune responses of antigen-specific T cells in peptide vaccine clinical trials.
 ...
PMID:Direct measurement of peptide-specific CD8+ T cells using HLA-A2:Ig dimer for monitoring the in vivo immune response to a HER2/neu vaccine in breast and prostate cancer patients. 1516 2

The clinical effects of targeting Her-2/neu in prostate carcinoma are not known. This study explores the feasibility of molecular profiling to determine the correlation between Her-2/neu expression and hormonal sensitivity. Patients with progressive androgen-independent prostate carcinoma were eligible to participate in the study. Her-2/neu expression was assessed on pretreatment tissue specimens and on bone marrow obtained in progressive androgen-independent disease. Her-2/neu expression was evaluated by immunohistochemistry and by fluorescence in situ hybridization in a consecutive series of 26 progressive androgen-independent prostate cancer patients. Twenty four bone marrow biopsy specimens and 16 prostate biopsies from 26 patients were analyzed. These biopsies were categorized by androgen sensitivity at the time of the biopsy. In total, 90% of specimens from bone marrow were Her-2/neu positive, and 10% of the specimens were Her-2/neu negative. Of the prostate biopsies, all were from patients with androgen-dependent disease. Three of 13 androgen-dependent prostate biopsies (23%) overexpressed Her-2/neu. Of the 10 tumor samples analyzed by fluorescence in situ hybridization, genomic amplification of the Her-2/neu locus was not detected in any of the metastatic prostate tumors. Her-2/neu expression varies with the clinical state of patients with prostate carcinoma: Accurate Her-2/neu profiling requires sampling metastatic tissue in patients with metastatic disease. Her-2/neu sampling from metastatic prostate carcinoma is not feasible until more reliable and practical methods can be developed.
 ...
PMID:Her-2/neu expression in prostate cancer: a dynamic process? 1526 47

The vitamin D receptor (VDR) is a member of the steroid/retinoid receptor superfamily of nuclear receptors and has potential tumor-suppressive functions in prostate and other cancer types. Vitamin D3 (VD3) exerts its biological actions by binding within cells to VDR. The VDR then interacts with specific regions of the DNA in cells, and triggers changes in the activity of genes involved in cell division, cell survival, and cellular function. Using human primary cultures and the prostate cancer (PCa) cell line, ALVA-31, we examined the effects of VD3 under different culture conditions. Complete G0/G1 arrest of ALVA-31 cells and approximately 50% inhibition of tumor stromal cell growth was observed. To determine changes in gene expression patterns related to VD3 activity, microarray analysis was performed. More than approximately 20,000 genes were evaluated for twofold relative increases and decreases in expression levels. A number of the gene targets that were up- and down-regulated are related to potential mechanisms of prostatic growth regulation. These include estrogen receptor (ER), heat shock proteins: 70 and 90, Apaf1, Her-2/neu, and paxillin. Utilizing antibodies generated against these targets, we were able to confirm the changes at the protein level. These newly reported gene expression patterns provide novel information not only potential markers, but also on the genes involved in VD3 induced apoptosis in PCa.
 ...
PMID:Vitamin D3 modulated gene expression patterns in human primary normal and cancer prostate cells. 1536 55

Androgen withdrawal is the only effective therapy for patients with advanced prostate cancer, but progression to androgen independence ultimately occurs in almost all patients. Novel therapeutic strategies targeting molecular mechanisms that mediate resistance to hormonal and chemotherapeutic treatment are highly warranted. Here, we aimed to evaluate the expression of potential therapeutic targets in advanced prostate cancer. A tissue microarray (TMA) containing samples from 535 tissue blocks was constructed, including benign prostatic hyperplasia as controls (n = 65), prostatic intraepithelial neoplasia (PIN; n = 78), clinically localized prostate cancers (n = 181), as well as hormone-refractory local recurrences (n = 120) and distant metastases (n = 91). The expression of 13 different proteins was analyzed using immunohistochemistry (Bcl-2, p53, ILK, Syndecan-1, MUC-1, EGFR, HER2/neu, HSP-90, Ep-CAM, MMP-2, CD-10, CD-117 and Ki67). Significant overexpression in hormone-refractory prostate cancer and metastatic tissue compared to localized prostate cancer was found for Ki67 (64% vs. 9%), Bcl-2 (11% vs. 1%), p53 (35% vs. 4%), Syndecan-1 (38% vs. 3%), EGFR (16% vs. 1%) and HER2/neu (16% vs. 0%). Overexpression of CD-117 was restricted to 1 single metastasis. All other markers did not show relevant differences in expression between subgroups. Taken together, p53, Bcl-2, Syndecan-1, EGFR and HER2/neu are preferentially expressed in hormone-refractory and metastatic prostate cancer. Selected inhibition of these targets might offer a strategy to treat advanced tumors and prevent further progression. Treatment decisions should not be based on findings in primary tumors but rather on tissues from recurrent or metastatic lesions.
 ...
PMID:Expression patterns of potential therapeutic targets in prostate cancer. 1547 3

The bispecific antibody (BiAb) anti-CD3 x anti-Her2/neu (Her2Bi), combines Her2/neu targeting with nonmajor histocompatibility complex-restricted cytotoxicity mediated by activated T cells (ATCs). To evaluate this adaptive immunotherapeutic strategy for augmenting antitumor immune response toward hormone-refractory prostate cancer (HRPC), normal donor or patient T cells were activated with anti-CD3, expanded ex vivo in interleukin-2, and then armed with Her2Bi (5-500 ng per million ATCs). In vitro, arming ATCs with Her2Bi increased the percent specific cytotoxicity toward PC-3 prostate adenocarcinoma cells 2-3 fold and increased the secretion of Th1 cytokines granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and interferon-gamma when compared with unarmed ATCs or ATCs armed with an irrelevant BiAb. Her2Bi-armed ATCs administered with PC-3 (Winn Assay) or injected intratumorally prevented development or induced remissions, respectively, of PC-3 tumors in severe combined immunodeficient beige mice. Intravenously administered Her2Bi-armed ATCs localized to PC-3 xenografts mediated cytotoxicity toward tumor cells and produced significant tumor growth delay of PC-3 tumors, but not Her2/neu-negative LS174T colon adenocarcinoma xenografts. By flow cytometry analyses, Her2Bi-armed ATCs had a proliferative advantage over unarmed ATCs and persisted in the circulation and tumor tissues longer than unarmed ATCs. These findings suggest that Her2Bi-armed ATC therapy may be an effective, nontoxic, tumor-specific treatment for Her2-positive HRPC.
Clin Prostate Cancer 2004 Sep
PMID:Anti-CD3 x anti-HER2 bispecific antibody effectively redirects armed T cells to inhibit tumor development and growth in hormone-refractory prostate cancer-bearing severe combined immunodeficient beige mice. 1547 95

High levels of fatty acid synthase (FAS) have been found in cancer precursor lesions of the colon, stomach, esophagus, oral cavity, prostate, and breast. Inhibition of FAS with C75 has led to a significant antitumor effect in both human breast and prostate cancer xenografts. Recently, HER2/neu, which has also been identified in preneoplastic breast lesions, has been shown to regulate FAS expression through the PI3K/Akt signal transduction pathway rendering them susceptible to FAS inhibition. Utilizing the neu-N transgenic mouse model of mammary cancer, weekly treatment of the neu-N mice with C75 (30 mg/kg) for 10 weeks significantly delayed tumor progression. Only 20% of the C75-treated transgenic mice developed mammary carcinoma by 220 days, compared to 50% in the vehicle control animals. Two C75-treated animals never developed mammary cancer. Analysis of mammary tissue following 10 weeks of C75 treatment revealed a significant delay in mammary maturation as manifested by a reduction of the number and caliber of mammary ducts and budding epithelial structures. Apoptotic changes were increased, DNA synthesis was decreased, and the expressions of FAS, neu, Akt, phospho-Akt, and p21(waf1) were all decreased when compared to vehicle controls and FVB/N mice. Importantly, these effects were restricted to the breast epithelial cells that overexpressed neu, not involving other normal duct structures in the skin, liver, or kidney. C247, an FAS inhibitor chemically distinct from C75, significantly delayed mammary maturation similar to C75. Thus, pharmacological inhibition of FAS affects the expression of key oncogenes involved in both cancer development and maintenance of the malignant phenotype. Moreover, these data identify FAS as a potential novel drug target for breast cancer chemoprevention.
 ...
PMID:Fatty acid synthase inhibitors are chemopreventive for mammary cancer in neu-N transgenic mice. 1548 85

The androgen receptor (AR) is implicated in regulation of cellular events in advanced prostate cancer. It is expressed in primary tumours as well as in metastases from patients who failed endocrine therapy. Activation of the AR in metastatic tumours occurs as a result of increased sensitivity of the receptor, point mutations that alter activation spectrum and in response to various nonsteroidal compounds. Peptide growth factors that activate the signalling pathway of mitogen-activated protein kinases (MAPK) stimulate AR activity in ligand-independent or synergistic manner. Outcome of nonsteroidal activation depends on cellular and promoter context. AR activation by Her-2/neu is associated with enhanced tumour growth of the LAPC-4 xenograft. The issue whether MAPK or protein kinase Akt involved in growth factor signalling directly phosphorylate the AR is a matter of debate. AR ligand-independent activation by protein kinase A activators was also demonstrated. Under physiological conditions, potentiation of AR activity by low doses of androgen might be of importance in prostate cancer patients who receive endocrine therapy. Interleukin-6 (IL-6) and related cytokines also activate AR in a ligand-independent and synergistic manner. IL-6 is a pleiotropic regulator of tumour growth, which in some prostate cancers acts as a paracrine growth inhibitor and in other cases as an autocrine growth stimulator. Activation of the AR by IL-6 requires functional pathways of Janus kinases/signal transducers and activators of transcription factors and MAPK. Studies on AR co-activators implicated in ligand-independent activation may further improve understanding of cross-talk between signalling pathways.
 ...
PMID:Androgen receptor cross-talk with cell signalling pathways. 1551 41

The HER2/neu protein is over-expressed in multiple epithelial tumors and the source of immunogenic peptides currently under investigation in vaccine trials in ovarian and breast cancers. We sought to define the correlation between HER2/neu expression and risk for prostate cancer recurrence and then determine the potential efficacy of anti-HER2/neu vaccination in prostate cancer patients at risk for recurrence. The risk for prostate-specific antigen (PSA) recurrence in 95 patients undergoing prostatectomy at the Walter Reed Army Medical Center (WRAMC) was calculated and correlated to HER2/neu expression, as determined by immunohistochemical staining. Peripheral blood lymphocytes (PBL) were then isolated from six consecutive human leukocyte antigen (HLA) A2+ patients with HER2/neu+ prostate tumors. These PBL were grown in parallel cultures and stimulated either with no peptide, HER2/neu E75 peptide, or control peptide. The cultures were compared for stimulated proliferation, induced peptide-specific cytotoxicity and tumor-specific cytotoxicity. When assessed by risk group, 69% of the high risk patients' tumors over-expressed HER2/neu compared to 47% of the intermediate risk group (p<0.05). Evaluation of the in vitro immune response of PBL isolated from six consecutive prostate cancer patients revealed a statistically significant increase in E75-stimulated lymphocytic proliferation. E75-stimulated lymphocytes demonstrated an E75-specific cytolytic response in 6/6 prostate cancer patients that increased with successive stimulations. Moreover, these E75-specific lymphocytes also demonstrated tumor-specific lysis against HER2/neu-expressing prostate cancer cell lines. The majority of prostate cancer patients at high risk for recurrence have HER2/neu expressing tumors. Hence, HER2/neu is a viable target for immunotherapeutics such as preventative immunization strategies with HER2/neu peptide vaccines.
 ...
PMID:Preclinical testing of a peptide-based, HER2/neu vaccine for prostate cancer. 1554 16


<< Previous 1 2 3 4 5 6 Next >>