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)

Prostate cancers are resistant to many anticancer agents at the time of presentation. P-glycoprotein (P-gp) is believed to mediate multidrug resistance phenotype. To elucidate the possible role of P-gp in such an intrinsic drug resistance of prostate cancers, its expression was examined immunohisochemically using two P-gp isoform-specific monoclonal antibodies (mAbs) with the paraffin embedded prostate samples derived from five nonmalignant and 30 untreated prostate cancer patients. In all of five normal prostate tissues, P-gp was consistently detected with both mAbs in the epithelial cells, especially at their apical site, and the level of expression was higher in the inner zone than in outer zone. On the other hand, tumor cells expressed P-gp heterogeneously in distribution and intensity; in 25 of 30 malignant cases P-gp expression was clearly demonstrated, whereas its expression was only faintly detected in other cases. However, the staining intensities for P-gp in prostate cancer cells were generally lower than in normal prostate epithelial cells. Thus, not only normal prostate epithelial cells but prostate cancer cells express at least MDR1 P-gp isoform. These results suggest that P-gp expression might play some role in intrinsic drug resistance of prostate cancer cells to many cytotoxic drugs as well as in relative resistance of the inner zone cells to the prostate carcinogenesis.
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PMID:Demonstration of MDR1 P-glycoprotein isoform expression in benign and malignant human prostate cells by isoform-specific monoclonal antibodies. 1070 36

Prostate cancer has become the most common cancer in males and the second most common cause of male cancer death in England and Wales. Death rates have doubled over the last 20 years. Prostate cancer is characterized by a high initial response rate to hormonal therapy. Drug-resistance is a significant cause of relapse in cancer. The multidrug resistance genes (MDR) encode resistance to a diverse family of cytotoxic chemotherapy agents. There are four known MDR genes, two of which are present in humans. MDR1 encodes for P-glycoprotein, a 170-kDa transmembrane calcium-dependent efflux pump. We examined P-glycoprotein expression by immunocytochemistry in 96 patients with prostate cancer and 20 patients with benign prostatic hypertrophy. A direct correlate was found between tumor grade, stage, and prostate specific antigen levels, indicating the possible significance of this protein in recurrent prostate cancer.
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PMID:Expression of the multidrug resistance gene in human prostate cancer. 1076 19

Intrinsic and acquired antineoplastic drug resistance remain a major problem for advanced prostate cancer treatment. In order to characterize mechanisms of anti-neoplastic drug resistance in human prostate cancer cell lines, resistant sublines of four of the commonly studied prostate cancer cell lines (DU 145, PC-3, PPC-1, and TSU-PR1) were selected following exposure to increasing concentrations of doxorubicin (from 10-1000 nM). Sensitivity patterns of the parent and doxorubicin-resistant sublines to various anti-neoplastic drugs, including adriamycin, amsacrine, etoposide, camptothecin, vinblastine, vincristine, fluorodeoxyuridine, and melphalan, were determined using a sulforhodamine B growth inhibition assay. The expression of three well-described antineoplastic drug resistance proteins, P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and lung resistance protein (LRP), was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR) assays specific for each of the mRNA species, and using immunocytochemical staining procedures specific for each of the polypeptides. All four of the doxorubicin-selected prostate cancer cell lines exhibited a multidrug resistance phenotype; administration of verapamil restored doxorubicin sensitivity for each of the drug resistant sublines. Although significant MDR1 expression was not detected in any of the parent cell lines before drug exposure by RT-PCR analysis or by immunocytochemistry, both MDR1 mRNA and P-gp protein were expressed by the TSU-PR1 Adr 1000 subline. In contrast, MRP mRNA and protein were present in each of the prostate cancer cell lines before doxorubicin-selection, and an increase in MRP expression appeared to accompany the acquisition of drug resistance in DU 145, PC-3, and PPC-1 doxorubicin-resistant sublines. LRP was variably expressed by each of the parent and resistant cell lines. These data suggest that drug resistance in human prostate cancer may be multifactorial, with MRP and LRP frequently expressed in prostate cancer cells before antineoplastic drug treatment and P-gp expression occasionally acquired after drug exposure.
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PMID:Doxorubicin-resistant variants of human prostate cancer cell lines DU 145, PC-3, PPC-1, and TSU-PR1: characterization of biochemical determinants of antineoplastic drug sensitivity. 1107 91

Multidrug resistant prostate cancer cell lines DU 0.03 and PC 0.03 were established from the parental prostate cancer cell lines DU145 and PC-3 respectively by stepwise selection in doxorubicin (DOX) from 0.001 to 0.03 &mgr;g/ml. As cells adapted to each concentration of DOX. the drug concentration was increased by 0.001 &mgr;g/ml. The chemosensitivity of each line was determined by growth inhibition assay. The DU 0.03 and PC 0.03 lines exhibit a 5-10-fold and 1.3-2.8-fold increase in resistance to anthracyclines, vinblastine (VLB) and mitozantrone (Mito), respectively. Verapamil (5 &mgr;M) partially reversed the resistance to the anthracycline and completely reversed the resistance to VLB and Mito. Drug kinetic studies measured by intracellular accumulation of (3)H-daunorubicin demonstrated a 3 fold decrease in the level of intracellular (3)H-daunorubicin in the PC 0.03 and DU 0.03 resistant lines compared with their respective parental line. This effect was partially reversed by 5 &mgr;M verapamil. The expression of MDR1 and MRP genes was analysed by Northern blotting and RT-PCR. P-glycoprotein (Pgp) and MRP protein were tested by immunocytochemistry staining using the monoclonal antibodies J-SB1. C219 and MRK16 (Pgp) and MRPm6 and MRPr1 (MRP). Neither Northern blot analysis nor the more sensitive RT-PCR demonstrated detectable MDR1 transcripts in any of the prostate cancer cell lines and the three Pgp monoclonal antibodies failed to reveal expression of Pgp. A 2-4-fold increase in MRP1 mRNA levels in the drug resistant DU 0.03 and PC 0.03 lines were demonstrated by both Northern blotting and RT-PCR consistent with the findings observed after staining by the two specific monoclonal antibodies, MRPm6 and MRPr1. Southern blot analysis demonstrated a 2-fold increase in the MRP1 gene copy number in the PC 0.03 line but not in the DU 0.03 line, suggesting that the overexpression of the MRP gene was regulated at the level of transcription in the latter line. We conclude that MRP1 not MDR1 overexpression. contributes to acquired drug resistance in these two prostate cancer cell lines. Prostate Cancer and Prostatic Diseases (2000) 3, 66-75
Prostate Cancer Prostatic Dis 2000 Aug
PMID:MRP1 not MDR1 gene expression is the predominant mechanism of acquired multidrug resistance in two prostate carcinoma cell lines. 1249 2

Advanced hormone-refractory prostate cancer remains a therapeutic challenge, because all available pharmaceutical concepts have been ineffective in improving cancer-specific survival. Failure of chemotherapy may be caused by multidrug resistance (MDR) mechanisms protecting cancer cells against cytotoxic drugs, and the question arises whether prostate cancer is also using MDR principles resulting in resistance against chemotherapeutic agents. In consequence, an array of diverse pathways known to lead to MDR such as MDR1, MRPs, glutathione, and apoptosis have been examined and partially established at varying degrees in hormone-refractory prostate cancer. Thus, evidence keeps accumulating for the involvement of some MDR mechanisms in the chemoresistance of prostate cancer in vitro and in vivo. For some of them, e.g. MRP1, functional expression appears to be probable. This lends credit to the idea that reversal, circumvention, or overcoming of MDR pathways in advanced prostate cancer may be feasible and will lead to new avenues with improved treatment efficacy in otherwise intractable disease.
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PMID:Multidrug resistance in prostate cancer. 1277 27

Aberrant DNA methylation patterns may be the earliest somatic genome changes in prostate cancer. Using real-time methylation-specific PCR, we assessed the extent of hypermethylation at 16 CpG islands in DNA from seven prostate cancer cell lines (LNCaP, PC-3, DU-145, LAPC-4, CWR22Rv1, VCaP, and C42B), normal prostate epithelial cells, normal prostate stromal cells, 73 primary prostate cancers, 91 metastatic prostate cancers, and 25 noncancerous prostate tissues. We found that CpG islands at GSTP1, APC, RASSF1a, PTGS2, and MDR1 were hypermethylated in >85% of prostate cancers and cancer cell lines but not in normal prostate cells and tissues; CpG islands at EDNRB, ESR1, CDKN2a, and hMLH1 exhibited low to moderate rates of hypermethylation in prostate cancer tissues and cancer cell lines but were entirely unmethylated in normal tissues; and CpG islands at DAPK1, TIMP3, MGMT, CDKN2b, p14/ARF, and CDH1 were not abnormally hypermethylated in prostate cancers. Receiver operator characteristic curve analyses suggested that CpG island hypermethylation changes at GSTP1, APC, RASSF1a, PTGS2, and MDR1 in various combinations can distinguish primary prostate cancer from benign prostate tissues with sensitivities of 97.3-100% and specificities of 92-100%. Hypermethylation of the CpG island at EDNRB was correlated with the grade and stage of the primary prostate cancers. PTGS2 CpG island hypermethylation portended an increased risk of recurrence. Furthermore, CpG island hypermethylation patterns in prostate cancer metastases were very similar to the primary prostate cancers and tended to show greater differences between cases than between anatomical sites of metastasis.
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PMID:Hypermethylation of CpG islands in primary and metastatic human prostate cancer. 1502 33

The efficiency of chemotherapy is often decreased by the development of resistance of cancer cells to cytostatic drugs. This phenomenon is in most cases caused by the activity of the various ABC transporters, multidrug-resistance (MDR) gene-encoded p-glycoproteins, that pump anticancer drugs out of the cells. The inhibition of the activities of the MDR proteins MDR1 and MRP was investigated via the administration of two new organosilicon compounds, alis-409 and alis-421. The study was focused on the inhibition of MDR by blocking the ADR1 gene expression and through the inhibition of the pump-function of mdr-p-glycoprotein, in human breast cancer cell lines expressing mrp and prostate cancer cell line (PC-3). Apoptosis induction and the interaction between epirubicin and the silicon-substituted compounds were studied in human MDR-1 gene-transfected mouse lymphoma and its parent cell line, Colo320/MDR-LRP and sensitive subline Colo205, by means of rhodamine 123 accumulation. The activity of MRP1 p-glycoprotein was studied in human breast cancer cell lines such as HTB-26/MRP1 and two MRP-negative breast cancer cell lines, T47D and MCF7, by carboxyfluorescein accumulation, and on a stomach cancer cell line. The activity of MRP in 257P/MDR and its drug-sensitive derivative were studied in human stomach cancer cells by daunorubicin accumulation in a flow cytometer. The two representative organosilicon derivatives, alis-409 and alis-421, showed antiproliferative effects without apoptosis induction. The drug accumulation in the human MDR1 gene-transfected mouse lymphoma cells was increased without down-regulation of the MDR1 gene expression tested by RT-PCR assay. The rhodamine uptake was increased in L5178/MDR1 and Colo320/MDR1-LRP, but not drug-sensitive human breast cancer MCF-7 and T47D, and L5178 mouse lymphoma parent cells in the presence of alis-409 and alis-421. The MRP-mediated carboxyfluorescein accumulation in HTB-26/MRP human breast cancer cells and daunorubicin accumulation in human stomach cancer cells 257P/MDR were not modified by these alis compounds. A synergistic interaction between epirubicin and the silicon-substituted resistance modifiers was found only in MDR1-mediated MDR in the case of colo-320/MDR1-LRP cells and mouse lymphoma cells transfected with the human MDR1 gene. The results indicate that the organosilyl derivatives specifically act on MDR1 p-glycoprotein 170. The alis compounds act on pgp170 in a way which is similar to verapamil isomers.
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PMID:New silicon compounds as resistance modifiers against multidrug-resistant cancer cells. 1516 Oct 39

Prostate cancer is a highly prevalent malignancy, which is clinically silent but curable while organ-confined. Because available screening methods show poor sensitivity and specificity, the development of new molecular markers is warranted. Epigenetic alterations, mainly promoter hypermethylation of cancer-related genes, are common events in prostate cancer and might be used as cancer biomarkers. Moreover, the development of quantitative, high-throughput techniques to assess promoter methylation enabled the simultaneous screening of multiple clinical samples. From the numerous cancer-related genes hypermethylated in prostate cancer only a few proved to be strong candidates to become routine biomarkers. This small set of genes includes GSTP1, APC, RARbeta2, Cyclin D2, MDR1, and PTGS2. Single and/or multigene analyses demonstrated the feasibility of detecting early prostate cancer, with high sensitivity and specificity, in body fluids (serum, plasma, urine, and ejaculates) and tissue samples. In addition, quantitative hypermethylation of several genes has been associated with clinicopathologic features of tumor aggressiveness, and also reported as independent prognostic factor for relapse. The identification of age-related methylation at specific loci and the differential frequency of methylation among ethnical groups, also provided interesting data linking methylation and prostate cancer risk. Although large trials are needed to validate these findings, the clinical use of these markers might be envisaged for the near future.
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PMID:Epigenetic markers for molecular detection of prostate cancer. 1732 24

Bioluminescence imaging (BLI) is becoming indispensable to the study of transgene expression during development and, in many in vivo models of disease such as cancer, for high throughput drug screening in vitro. Because reaction of d-luciferin with firefly luciferase (fLuc) produces photons of sufficiently long wavelength to permit imaging in intact animals, use of this substrate and enzyme pair has become the method of choice for performing BLI in vivo. We now show that expression of the ATP-binding cassette (ABC) family transporter ABCG2/BCRP affects BLI signal output from the substrate d-luciferin. In vitro studies show that d-luciferin is a substrate for ABCG2/BCRP but not for the MDR1 P-glycoprotein (ABCB1/Pgp), multidrug resistance protein 1 (MRP1/ABCC1), or multidrug resistance protein 2 (MRP2/ABCC2). d-Luciferin uptake within cells is shown to be modulated by ABC transporter inhibitors, including the potent and selective ABCG2/BCRP inhibitor fumitremorgin C. Images of xenografts engineered to express transgenic ABCG2/BCRP, as well as xenografts derived from the human prostate cancer cell line 22Rv1 that naturally express ABCG2/BCRP, show that ABCG2/BCRP expression and function within regions of interest substantially influence d-luciferin-dependent bioluminescent output in vivo. These findings highlight the need to consider ABCG2/BCRP effects during d-luciferin-based BLI and suggest novel high throughput methods for identifying new ABCG2/BCRP inhibitors.
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PMID:ABCG2/BCRP expression modulates D-Luciferin based bioluminescence imaging. 1790 48

The intrinsic or acquired resistance to multiple drugs (MDR) of cancer cells remains one of the main obstacles for chemotherapy. Development of small molecule targeting to hypoxia inducible factor-1 (HIF-1) has been recently proposed as strategy for treatments of drug-resistant solid tumors. In the present study, emodin, proven as a reactive oxygen species (ROS) generator by our previous work, was applied in combination with cisplatin and other chemotherapeutic drugs in the multidrug resistant prostate carcinoma cell line DU-145 and normal human dermal fibroblasts. Results showed that emodin/cisplatin co-treatment remarkably elevated ROS level and enhanced chemosensitivity in DU-145 cells, compared with cisplatin-only treatment, but exerted little effect on non-tumor cells. The effect of co-treatment on MDR1 gene and its upstream regulator HIF-1 was then investigated in DU-145. Co-treatment downregulated MDR1 expression and promoted drug retention, and meanwhile suppressed transactivation of HIF-1 in response to hypoxia without changing expression of HIF-1 alpha. The experiments on tumor-bearing mice showed that co-treatment inhibited the tumor growth in vivo, owing to oxidative stress and MDR1 down-regulation within tumors. HIF-1 transactivation and clonegenesis were suppressed in cells isolated from the tumors. Finally, examinations for the body weight, the organ histology and the antioxidant capacity of serum suggested that no systemic toxicity related to co-treatment was discernable. In conclusions, emodin, as a novel small inhibitor of HIF-1, may be recognized an effective adjunctive to improve efficacy of cytotoxic drugs in prostate cancer cells with over-activated HIF-1 and potent MDR.
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PMID:Emodin enhances cytotoxicity of chemotherapeutic drugs in prostate cancer cells: the mechanisms involve ROS-mediated suppression of multidrug resistance and hypoxia inducible factor-1. 1824 55


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