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)

beta-Lapachone, a plant product, has been shown to be a novel inhibitor of DNA topoisomerase I, with a mode of action different from camptothecin and a chemical structure distinct from those of current anti-cancer drugs. We observed that beta-lapachone, at concentrations of less than 8 microM, induces cell death with characteristics of apoptosis in human prostate cancer cell lines. This effect of beta-lapachone was also observed in a human promyelocytic leukemia cell line (HL-60). beta-Lapachone-induced apoptosis is independent of p53 expression, and ectopic overexpression of bcl-2 did not confer significant resistance to beta-lapachone. Among other human carcinoma and adenoma cell lines tested, human breast and ovary carcinoma showed sensitivity to the cytotoxic effect of beta-lapachone without manifesting signs of apoptosis. These results suggest that beta-lapachone is a potential compound to be added to cancer chemotherapy, particularly for prostate cancer.
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PMID:Induction of apoptosis by beta-lapachone in human prostate cancer cells. 764 Nov 81

The TP53 gene mutation pattern in prostatic cancer was examined in relation to progression and survival, using archival formalin-fixed pre- and post-treatment tumour specimens from 84 prostatic cancer patients. Thirty-four had hormone-sensitive tumours and 50 were hormone-resistant. Six of the 34 (18 per cent) therapy-responding tumours and 19 of the 50 (38 per cent) hormone-resistant tumours showed p53 protein accumulation in the post-treatment specimen. Both pre- and post-treatment specimens from these 25 patients were analysed for mutation of the conserved regions of the TP53 gene (exons 5-8), using constant denaturant gel electrophoresis (CDGE) followed by DNA sequencing. In the post-treatment samples, mutations were detected in three of the six patients with hormone-responsive tumours and in 11 of the 19 patients with hormone-resistant tumours. The three (100 per cent) patients with therapy-responsive tumours with mutations and nine of the 11 (82 per cent) patients with therapy-resistant tumours with mutations died of the disease. Thirteen of the 14 mutations in the post-treatment specimens were transitions, 11 occurring at CpG dinucleotides in which codon 273 was involved in ten. A significantly higher proportion of tumours with mutations were poorly differentiated compared with tumours without mutation (P < 0.04). Our findings indicate that TP53 mutation is a late event in tumour development of the prostate gland and that codon 273 might be a 'hotspot' for mutation in the progression of the disease.
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PMID:TP53 mutations in prostatic cancer. Analysis of pre- and post-treatment archival formalin-fixed tumour tissue. 767 92

A study was made of the incidence of p53 mutations in Japanese males with prostate cancer or benign prostatic hyperplasia. Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) was used as a primary screening technique with gene sequencing being carried out in positive cases. Two out of 21 prostate cancers (9.5%) were found to have p53 mutations. These were stage B2 and D2 prostate cancers. No abnormalities were found in the remaining cases or benign prostatic hyperplasia. Mutations of the p53 gene would thus appear infrequent in the tumourigenesis of primary prostate cancer.
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PMID:Infrequent involvement of p53 gene mutations in the tumourigenesis of Japanese prostate cancer. 769 Nov 45

Prostatic cancer is the second most frequent cancer in men in industrialised countries. The histological analysis of its initial development demonstrates the existence of precancerous lesions, PIN. The initial presence of several different cell populations accounts for the development of contingents of hormone-sensitive and hormone-resistant cells. The presence of numerous neuroendocrine cells appears to be a factor of poor prognosis. Hormones are intimately involved in the development of prostatic cancer and are an integral part of its treatment. Progress in molecular biology has furthered out knowledge of this disease. In particular, growth factors such as EGF and FGF are particularly involved and are starting to have a clinical application. The oncogene and anti-oncogene system is currently being explored (particularly p53 abd BCL 2). They are the basis for carcinogenesis and analysis of these factors will allow a better approach to the mechanisms of tumour induction and development.
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PMID:[Cancer of the prostate. 2. Physiology and cellular development]. 771 57

Progress toward understanding the biology of prostate cancer has been slow due to the few animal research models available to study the spectrum of this uniquely human disease. To develop an animal model for prostate cancer, several lines of transgenic mice were generated by using the prostate-specific rat probasin promoter to derive expression of the simian virus 40 large tumor antigen-coding region. Mice expressing high levels of the transgene display progressive forms of prostatic disease that histologically resemble human prostate cancer, ranging from mild intraepithelial hyperplasia to large multinodular malignant neoplasia. Prostate tumors have been detected specifically in the prostate as early as 10 weeks of age. Immunohistochemical analysis of tumor tissue has demonstrated that dorsolateral prostate-specific secretory proteins were confined to well-differentiated ductal epithelial cells adjacent to, or within, the poorly differentiated tumor mass. Prostate tumors in the mice also display elevated levels of nuclear p53 and a decreased heterogeneous pattern of androgen-receptor expression, as observed in advanced human prostate cancer. The establishment of breeding lines of transgenic mice that reproducibly develop prostate cancer provides an animal model system to study the molecular basis of transformation of normal prostatic cells and the factors influencing the progression to metastatic prostate cancer.
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PMID:Prostate cancer in a transgenic mouse. 772 80

To elucidate the role of the p53 tumor suppressor gene in prostate tumorigenesis, we probed for mutations in latent and clinical prostate cancers using single strand conformation polymorphism (SSCP) and restriction fragment length polymorphism (RFLP) analysis in combination with direct gene sequencing and immunohistochemical methodologies. Fifteen cases of subclinical and 32 cases of clinical carcinoma, the latter graded in stages A through D, were available for study. While p53 point mutations were detected in only 5 of 32 (16%) clinical cancers, no mutations were detected in latent disease. Of the carcinomas in stages B, C and D, 15% (2/13), 29% (2/7) and 9% (1/11) were positive for p53 mutations, respectively. Although no specific mutational patterns were observed, the aberrations found were predominantly single base missense substitutions. The data suggest not only an association of p53 mutation and progression of clinical prostate cancer, but also imply that some other mechanism(s) are at work in latent carcinoma.
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PMID:p53 mutations occur in clinical, but not latent, human prostate carcinoma. 773 11

The propensity of a cell to undergo apoptosis has been proposed to be a determinant for chemotherapy sensitivity that is not directly dependent on specific drug-target interactions. Androgen-independent prostate cancer is typically refractory to cytotoxic drugs, and we tested whether this is due to a loss of the ability to undergo apoptosis. Exposure of the hormone-insensitive and p53-negative human prostate carcinoma cell line PC-3 to 22 microM cisplatin, 1 microM camptothecin, 10 microM tenoposide, 135 nM vincristine, or 10 microM lovastatin for 72 h caused cell death, internucleosomal DNA fragmentation, and morphological changes typical for apoptosis. One microM cycloheximide prevented anticancer drug-induced apoptosis, whereas high concentration (1 mM) of cycloheximide alone induced apoptosis, indicating that protein synthesis was not needed for these cells to undergo apoptosis. Since cycloheximide affected DNA synthesis and proliferation of PC-3 cells, we tested whether the DNA polymerase inhibitor aphidicolin could also suppress drug-induced apoptosis. In contrast to cycloheximide, aphidicolin inhibited only vincristine-induced apoptosis. Cycloheximide prevented drug-induced changes in cell cycle distribution except for vincristine, while aphidicolin led to an accumulation of cells at the G1-S border independent of the drug used. These data indicate that macromolecular synthesis, active cell cycling, and p53 expression are not required for apoptosis to proceed in this system.
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PMID:Drug-induced apoptosis is not necessarily dependent on macromolecular synthesis or proliferation in the p53-negative human prostate cancer cell line PC-3. 774 12

Major differences in the long-term clinical response to castration therapy of prostatic carcinoma suggests intertumoral differences in cellular response and defines a need for identification of patients with an eventually positive outcome as well as those in need of additional treatment. Using morphometry, monoclonal antibodies against Bcl-2, c-myc, Ki-67, and p53 proteins, and an in situ method to visualize apoptotic cells, we examined the short-term response of prostatic tumors to castration in core biopsies from 18 prostatic cancer patients taken the day before and 7 days after castration. At the histological level, 3 tumors seemed practically unaffected by castration. In 15 tumors, castration induced vacuolization of tumor cell cytoplasm and decreases in nuclear area and Ki-67 index. In these 15 tumors, apoptotic index was significantly increased in 6, principally unaffected in 6, and decreased in 3. The 6 tumors responding with an increase in apoptotic index were WHO grade 1 or 2 and negative for p53, c-myc, and Bcl-2 or contained only few Bcl-2- or c-myc-positive tumor cells before therapy. The 12 tumors in which apoptotic index was unaffected or decreased were WHO grade 2 or 3 and immunopositive for one or more of p53, Bcl-2, and c-myc proteins before therapy. The Bcl-2 index was significantly increased in 10 patients. Prostatic tumors may respond in a variety of possibly predictable ways to castration therapy including a decrease in apoptotic index. The magnitude of these responses are not correlated in individual tumors, suggesting that the common classification of prostatic tumors as either androgen dependent (dying after castration) or independent (not responding at all to castration) may be an oversimplification.
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PMID:Castration therapy rapidly induces apoptosis in a minority and decreases cell proliferation in a majority of human prostatic tumors. 777 76

Mutation of the p53 gene is the most common genetic alteration in human cancers. The mutant p53 protein is more stable than the wild type and can be detected by immunohistology. The objective of the current study was to evaluate the immunohistological detection of p53 protein in prostate cancer and its utility as a prognostic indicator. We used a monoclonal anti-p53 antibody and immunostained primary prostate adenocarcinomas (stages A1 to D1) from 109 patients with a mean follow-up of 3.8 years (range, 1.3 to 9.3 years). Immunoreactivity for p53 was seen in 23 cancers (21%). There were 12 instances of progression (14%) among the p53-negative cancers versus seven (30%) among the p53-positive group. Survival analysis using three univariate statistical tests showed that p53 reactivity (P < .03), Gleason score (P < .01), and stage (P < .05) had significant effects on time to progression of prostate cancer. Multivariate analyses showed that Gleason score was significant with all three tests; p53 reactivity was significant with the Wilcoxon test but only approached significance by the log rank and Cox tests. When the analyses included only patients with Gleason scores 2 to 7 (N = 94), univariate analyses showed that p53 reactivity was strongly related to progression of prostate cancer (P < .007). Stage also was significant (P < 0.04), but Gleason score was not. Multivariate analyses showed only p53 reactivity to be significant (P < .007). In conclusion, mutation of the p53 gene may be involved in prostate cancer carcinogenesis. p53 reactivity marks an aggressive subset of prostate cancer and appears to be an independent prognostic indicator that is particularly valuable among the low to intermediate grade cancers.
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PMID:Immunohistochemical detection of p53 protein as a prognostic indicator in prostate cancer. 782 6

Digital image analysis provides objective measurements of tissue and cell analytes previously interpreted subjectively. Both analyte concentration determination and morphometric analyses are possible. Calibration of the instrument and the use of standards and controls are essential for precise and reproducible quantitation of the analyte. Multi-tissue blocks ensure reproducible staining of the batch in quantitative immunohistochemical assays such as breast cancer estrogen and progesterone receptors. These multi-tissue blocks can be shared among laboratories to reduce interlaboratory variation and to objectively quantitate estrogen and progesterone receptors in clinical trials. In colon carcinoma, p53 can be quantitated objectively by image analysis. In prostate carcinoma, morphometric analysis of nuclear shape, nuclear roundness factor, and variations in nuclear size are objective measurements which constitute the pathologist's nuclear grade. Developments in instrumentation have now made it possible to combine analyte determination (such as DNA ploidy) and morphologic analysis of tumors, a diagnostic improvement over either method alone. A study employing image analysis to detect and quantitate androgen receptors and p53 in formalin-fixed, paraffin-embedded prostate cancer biopsies is underway to determine the utility of androgen receptors in predicting response to hormonal therapy. Histopathological features such as nuclear size, shape, and pleomorphism must be converted to image features such as area, shape factor, and variance of the area; this feature vector must be correlated with the pathologist's expert opinion or diagnosis. Other applications of image analysis include quantitation of immunofluorescent assays such as anti-nuclear antigen or anti-cytoplasmic nuclear antigen. Fluorescent image analysis provides more precision and greater reproducibility, as well as reduced test costs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Quantitation and morphometric analysis of tumors by image analysis. 782 83


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