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)

Neuroendocrine (NE) differentiation in prostatic adenocarcinomas has been reported to be an early marker for development of androgen independence. Secretion of mitogenic peptides from nondividing NE cells is thought to contribute to a more aggressive disease by promoting the proliferation of surrounding tumor cells. We undertook studies to determine whether the prostate cancer cell line LNCaP could be induced to acquire NE characteristics by treatment with agents that are found in the complex environment in which progression of prostate cancer towards androgen independence occurs. We found that cotreatment of LNCaP cells with agents that signal through cyclic AMP-dependent protein kinase (PKA), such as epinephrine and forskolin, and with the cytokine interleukin-6 (IL-6) promoted the acquisition of an NE morphological phenotype above that seen with single agents. Convergent IL-6 and PKA signaling also resulted in potentiated mitogen-activated protein kinase (MAPK) activation without affecting the level of signal transducer and activator of transcription or PKA activation observed with these agents alone. Cotreatment with epinephrine and IL-6 synergistically increased c-fos transcription as well as transcription from the beta4 nicotinic acetylcholine receptor subunit promoter. Potentiated transcription from these elements was shown to be dependent on the MAPK pathway. Most importantly, cotreatment with PKA activators and IL-6 resulted in increased secretion of mitogenic neuropeptides. These results indicate that PKA and IL-6 signaling participates in gene transcriptional changes that reflect acquisition of an NE phenotype by LNCaP cells and suggest that similar signaling mechanisms, particularly at sites of metastasis, may be responsible for the increased NE content of many advanced prostate carcinomas.
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PMID:Interleukin-6- and cyclic AMP-mediated signaling potentiates neuroendocrine differentiation of LNCaP prostate tumor cells. 1171 82

Prostate cancer is a disease that may be amenable to immunotherapy approaches, as evidenced by the ability to induce human cytotoxic immune responses against prostate cancer cells. Recent interest in recombinant poxvirus vaccines coupled with the need for new prostate cancer therapies has led to the development of several recombinant poxvirus agents designed for prostate cancer treatment. Whether these agents will be effective in treating prostate cancer is under investigation in several ongoing and upcoming clinical trials. In the meantime, data from preclinical tumor models have provided information that may aid in improving recombinant poxviruses for clinical use. While animal studies have shown the ability of recombinant poxvirus vaccination to induce an immune response that protects against lethal tumor, these antitumor effects are variable and depend on a number of factors. Co-expression of immunomodulating gene products, such as cytokines and costimulatory molecules, have been shown to influence antitumor immunity; in fact, cytokine delivery alone can be enough to protect against tumor-related death. Patterns and levels of recombinant antigen expression also affect the immune response to that antigen, as seen by studies of various poxvirus promoters and cell compartment-targeting sequences. In addition, vaccine strategies targeting self-antigens have shown that immunological tolerance can negatively impact the induction of antitumor and antigen-specific immunity. Although vaccinia virus has been most intensely studied thus far, other poxviruses, including fowlpox and canarypox, are also promising vaccine candidates. These alternative vectors may circumvent some of the disadvantages associated with vaccinia virus, such as pre-existing vaccinia immunity. A deeper understanding of these factors and others that impact the development of antitumor immunity will be necessary to guide the development of recombinant poxviruses for prostate cancer therapy.
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PMID:Prospects and limitations of recombinant poxviruses for prostate cancer immunotherapy. 1171 62

Prostate-specific antigen (PSA) is expressed by prostate epithelial cells and has a highly restricted tissue distribution. Prostatic malignancies in 95% of patients continue to express PSA, making this antigen a good candidate for targeted immunotherapy. The goals of our studies are to generate a recombinant PSA adenovirus type 5 (Ad5-PSA) that is safe and effectively activates a PSA-specific T-cell response capable of eliminating prostate cancer cells, and to characterize the immunologic basis for this rejection. Here we show that immunization of mice with Ad5-PSA induced PSA-specific cellular and humoral immunity that was protective against a subcutaneous challenge with RM11 prostate cancer cells expressing PSA (RM11psa), but not mock-transfected RM11 tumor cells (RM11neo). Mice immunized with recombinant adenovirus type 5 encoding beta-galactosidase (Ad5-lacZ) did not generate protective immunity. Antitumor activity was predominantly mediated by CD8(+) T lymphocytes. Although Ad5-PSA immunization prior to RM11psa challenge was protective, Ad5-PSA immunization alone was not able to control the growth of existing RM11psa tumors. In contrast, established RM11psa tumors ranging in size from 500 to 1,000 mm(3) were efficiently eliminated if Ad5-PSA priming was followed 7 days later by intratumoral injection of recombinant canarypox viruses (ALVAC) encoding interleukin-12 (IL-12), IL-2, and tumor necrosis factor-alpha. In this case, antitumor immunity was still dominated by CD8(+) T lymphocytes, but natural killer cells became necessary for a maximal response. These data provide information on the effector cell populations in a protective immune response to prostate cancer and demonstrate the utility of an Ad5-PSA vaccine combined with cytokine gene delivery to eliminate large established tumors that are refractory to other interventional methods.
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PMID:Immunization with type 5 adenovirus recombinant for a tumor antigen in combination with recombinant canarypox virus (ALVAC) cytokine gene delivery induces destruction of established prostate tumors. 1174 87

Passively administered and actively induced antibodies have been associated with the eradication of circulating tumor cells and micrometastases in mice and humans. We have identified a series of cell surface carbohydrate and peptide antigens on melanomas, sarcomas, and cancer of the breast, prostate. ovary, and lung tissues. We found that breaking tolerance toward these tumor antigens was best achieved using vaccines containing antigens chemically conjugated to keyhole limpet hemocyanin (KLH) plus a potent immunological adjuvant (QS-21). To date, by using this approach to vaccination. antibodies have been induced in patients against glycolipid antigens GM2, GD2, GD3, FucosylGM1, Globo H, and Lewis Y, and glycoprotein (mucin) antigens Tn, sialyl Tn. TF, and MUC1. More recently, in a comparative study we investigated the T cell response induced by MUCI-KLH conjugates. Although a MUC1-specific T cell response was not consistently detected in any patient, the role of KLH in orienting the cytokine environment was crucial. We were able to confirm that KLH in these conjugate vaccines induces a Th1 T cell response as demonstrated by the high anti-KLH INF-gamma secretion and the IgGI and IgG3 subclasses of this high titer IgG antibodies induced. Clinical trials using KLH conjugated glycolipid and glycoprotein vaccines, are currently ongoing. These range from phase I/II single antigens trials with glycosilated MUC1, polysialic acid, synthetic Fucosyl GMI and GD2, to phase II trials with a polyvalent vaccine containing six or seven antigens. Randomized phase II trials with polyvalent vaccines are planned for initiation in 2001-2002 in patients with ovarian, breast, and prostate cancer.
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PMID:Keyhole limpet hemocyanin conjugate vaccines against cancer: the Memorial Sloan Kettering experience. 1176 20

Lung cancer is the most frequently occurring cancer in the world and causes more deaths in the United States than does colon, breast, and prostate cancer combined. Despite advances in treatment modalities including radiation, surgery, and chemotherapy, the overall survival in lung cancer remains low. The cytokine tumor necrosis factor alpha (TNFalpha) has been shown to regulate both apoptotic and antiapoptotic pathways. Activation of the transcription factor NF-kappaB appears to be the critical determinant of the antiapoptotic response to TNFalpha exposure in epithelial cells. A549 human lung carcinoma cells were infected with adenoviral constructs carrying dominant negative mutants of Rac1 and IKK or constitutively active mutant of Rac1, upstream effectors in TNF-mediated NF-kappaB activation. Cell death, apoptosis, and NF-kappaB activation were subsequently measured in response to TNFalpha exposure. Although TNFalpha alone had no cytotoxic effect, the expression of the dominant negative mutant of IKKbeta (Ad.IKKbetaKA) resulted in apoptotic cell death following TNFalpha exposure. Similarly, dominant negative mutant to Rac1 (Ad.N17Rac1) further sensitized A549 cells to IKKbetaKA-mediated TNFalpha-induced cell death. Conversely, a dominant active form of Rac1 (Ad.V12Rac1) ameliorated the cell death response to concurrent IKKbeta dominant negative mutant infection and TNFalpha exposure. These results suggest that concurrent inhibition of Rac1 and IKK pathways sensitizes lung cancer cells to TNFalpha-induced apoptosis.
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PMID:Simultaneous inhibition of Rac1 and IKK pathways sensitizes lung cancer cells to TNFalpha-mediated apoptosis. 1177 80

The authors describe a case of high-output cardiac failure in a patient with rapidly progressing prostate cancer for which no previously described cause could be found. His new onset and increasingly worsening heart failure corresponded to the rapid spread of his prostate cancer. The authors hypothesize that a cytokine released from the neoplastic cells or the bone was responsible for the high-output cardiac failure observed in this patient. (c)2001 CHF, Inc.
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PMID:High-output cardiac failure in a patient with prostate cancer. 1182 71

TRAIL is a pro-apoptotic cytokine believed to selectively kill cancer cells without harming normal ones. However, we found that in normal human prostate epithelial cells (PrEC) TRAIL is capable of inducing apoptosis as efficiently as in some tumor cell lines. At the same time, TRAIL did not cause apoptosis in several other human primary cell lines: aorta smooth muscle cells, foreskin fibroblasts, and umbilical vein endothelial cells. Compared to these primary cells, PrEC were found to contain significantly fewer TRAIL receptors DcR1 and DcR2 which are not capable of conducting the apoptotic signal. This result suggests that the unusual sensitivity of PrEC to TRAIL may result from their deficiency in anti-apoptotic decoy receptors. The protein synthesis inhibitor cycloheximide significantly enhanced TRAIL toxicity toward PrEC as measured by tetrazolium conversion but had little or no effect on other TRAIL-induced apoptotic responses. Although cycloheximide did not further accelerate the processing of caspases 3 and 8, it significantly enhanced cleavage of the caspase 3 substrate gelsolin, indicating that in PrEC a protein(s) with a short half-life may inhibit the activity of the executioner caspases toward specific substrates. As the majority of prostate cancers are derived from epithelial cells, our data suggest the possibility that TRAIL could be a useful treatment for the early stages of prostate cancer.
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PMID:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in normal prostate epithelial cells. 1185 Aug 32

Circulating T lymphocytes of patients with prostate cancer have been reported to have functional deficits, including low or absent zeta-chain expression. To determine whether these functional impairments could be reversed by prostate specific antigen-based vaccination therapy, 10 patients treated with recombinant human prostate specific antigen plus GM-CSF and eight others receiving prostate specific antigen plus oil emulsion in two pilot clinical trials were evaluated prior to and after vaccination for several immunologic end points, including zeta-chain expression and cytokine production by circulating T cells as well as the frequency of T cells able to respond to prostate specific antigen in ELISPOT assays. The flow cytometry assay for zeta-chain expression was standardized to allow for a reliable comparison of pre- vs post-vaccination samples. Prior to therapy, the patients were found to have significantly lower zeta-chain expression in circulating CD3(+) cells and a higher percentage of zeta-chain negative CD3(+) and CD4(+) cells than normal donors. The patients' peripheral blood mononuclear cells spontaneously produced more IL-10 ex vivo than those of normal controls. After vaccination, recovery of zeta-chain expression was observed in 50% of patients in both clinical trials. Also, spontaneous IL-10 secretion by peripheral blood mononuclear cells decreased following immunotherapy in patients treated with prostate specific antigen and GM-CSF. The frequency of prostate specific antigen-reactive T cells was detectable in 7 out of 18 patients vs 4 out of 18 patients prior to vaccination. Only one of 18 patients was a clinical responder. The vaccine had stimulatory effects on the patients' immune system, but post-vaccine immune recovery could not be correlated to progression-free survival in this small cohort of patients with prostate cancer.
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PMID:Recovery of zeta-chain expression and changes in spontaneous IL-10 production after PSA-based vaccines in patients with prostate cancer. 1187 May 1

Integrin alpha(v)beta(3) is involved in varied cell biological activities, including angiogenesis, cell adhesion, and migration on several extracellular matrix components. Although alpha(v)beta(3) is not typically expressed in epithelial cells, it is expressed in macrophages, activated leukocytes, cytokine-stimulated endothelial cells, osteoclasts, and certain invasive tumors. Interestingly, the adhesion and migration of breast cancer cells on bone matrix are mediated, in part, by alpha(v)beta(3). Similar to breast cancer cells, prostate cancer cells preferentially metastasize to the bone. The biological events that mediate this metastatic pattern of prostate cancer are not well defined. This review discusses the role alpha(v)beta(3) plays in prostate cancer progression, with specific emphasis on bone metastasis and on alpha(v)beta(3) signaling in prostate cancer cells. The data suggest that alpha(v)beta(3), in part, facilitates prostate cancer metastasis to bone by mediating prostate cancer cell adhesion to and migration on osteopontin and vitronectin, which are common proteins in the bone microenvironment. These biological events require the activation of focal adhesion kinase and the subsequent activation of PI-3 kinase/Akt signaling pathway.
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PMID:The role of alpha(v)beta(3) in prostate cancer progression. 1198 38

Polymorphisms in the promoter regions of cytokine genes may influence prostate cancer (PC) development via regulation of the antitumor immune response and/or pathways of tumor angiogenesis. PC patients (247) and 263 controls were genotyped for interleukin (IL)-1beta-511, IL-8-251, IL-10-1082, tumor necrosis factor-alpha-308, and vascular endothelial growth factor (VEGF)-1154 single nucleotide polymorphisms. Patient control comparisons revealed that IL-8 TT and VEGF AA genotypes were decreased in patients compared with controls [23.9 versus 32.3%; P = 0.04, odds ratio (OR) = 0.66, 95% confidence interval (CI) 0.44-0.99 and 6.3 versus 12.9%; P = 0.01, OR = 0.45, 95% CI 0.24-0.86, respectively], whereas the IL-10 AA genotype was significantly increased in patients compared with controls (31.6 versus 20.6%; P = 0.01, OR = 1.78, 95% CI 1.14-2.77). Stratification according to prognostic indicators showed association between IL-8 genotype and log prostate-specific antigen level (P = 0.05). These results suggest that single nucleotide polymorphisms associated with differential production of IL-8, IL-10, and VEGF are risk factors for PC, possibly acting via their influence on angiogenesis.
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PMID:Influence of cytokine gene polymorphisms on the development of prostate cancer. 1206 76


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