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)

The present study was designed to investigate the efficacy of various combinations of chemotherapeutic agents in the treatment of prostatic cancer in a group refractory to antiandrogenic therapy (Group 1) and in a previous untreated group (Group 2). Therapeutic combinations of Estracyt (E) + Peplomycin (P) + Doxorubicin (Do) and P + Do + 5 FU (F) in Group 1 and E + P, Honvan (Ds) + P and E in Group 2 were carried out. The main objectives of this study were estimations of the efficacy of E and P in relation to the refractory cases of Group 1 and the efficacy of the combination E + P, in Group 2. This is the first such prospective, randomized, controlled study to be carried out in Japan in relation to prostatic cancer. The results obtained in the present study indicated that chemotherapeutic regimens including E provide some enhanced efficacy, but that the efficacy with regard to refractory cases is poor (23.1-27.3%), as has been reported of studies conducted in the USA and Europe. With regard to previously untreated cases, the E + P regimen achieved a relatively higher response rate than the other treatments (72.7 vs 44.5 or 50.0%). In the comparison of survival times and survival curves, there were no statistically significant differences among the various treatment subgroups. A comparison of survival curves revealed the interesting finding that the PAP-related response showed a clear correlation to the survival curves of Group 2 patients.
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PMID:A prospective, randomized controlled study on the treatment of stage C and stage D prostatic cancer with estracyt in combination with other chemotherapeutic agents. 246 51

Doxorubicin (Dx) effects on metastatic spreading of prostate cancer were investigated using a rat metastatic tumor (R3327-MatLyLu). Intravenous injection of monodispersed tumor cells resulted in tumor nodule formation in the lungs. A simultaneous bolus injection of Dx (3.2 mg/Kg) caused a significant decrease in lung colony formation and growth. However, Dx administered during the course of spontaneous metastasis, or as adjuvant chemotherapy 24 hours before surgical removal of primary tumor, caused a significant increase in metastasis to the lungs. It is concluded that an intravenous doxorubicin bolus injection does not provide an antimetastatic effect, but increases metastatic spreading of prostate tumor.
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PMID:Doxorubicin treatment increases metastasis of prostate tumor (R3327-MatLyLu). 321 66

In this study, we determined the maximum tolerated plasma concentration of suramin (within the predetermined study target range) when combined with doxorubicin in the treatment of androgen-independent prostate cancer. Twenty-four patients received suramin dosages based on proportional adjustment of the steady-state plasma suramin concentration to achieve the targeted plasma concentrations of 50-100, 101-150, 151-200, or 201-250 microg/ml. Doxorubicin (20 mg/m2) was administered i.v. over 24 h at weekly intervals. Suramin was given i.v. over 2 h twice weekly. Patients received treatment until dose-limiting toxicity or disease progression. Side effects similar to those reported for suramin and doxorubicin administered as individual agents were observed. Dose-limiting motor neuropathy developed in three patients (13%). Twelve of 24 evaluable patients (50%; 95% confidence interval, 28-71%) and 6 of 10 evaluable patients (60%; 95% confidence interval, 26-88%) had a >50% decrease of prostate-specific antigen and measurable lesions, respectively. The maximum tolerated plasma level of suramin when combined with doxorubicin was 151-200 microg/ml. Future studies on suramin combined with doxorubicin or other agents could be performed using a fixed dosing scheme with a targeted suramin steady-state plasma concentration of 200 microg/ml.
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PMID:Phase I study of suramin combined with doxorubicin in the treatment of androgen-independent prostate cancer. 960 77

Mdm2 is a nuclear phosphoprotein which functions as a negative feedback regulator of the p53 tumor suppressor gene. In this study, we investigated the alteration of Mdm2 and p53 in three human cancer cell lines containing either a wild-type or mutant p53 gene after treatment with Adriamycin (doxorubicin, ADR), a DNA damaging agent. We found that human breast cancer MCF-7 cells containing wild-type p53 were much more susceptible to ADR compared to human breast cancer MDA-MB-231 and human prostate cancer Du-145 cells which contain mutant p53. ADR resulted in a significant dose-dependent accumulation of p53 protein in MCF-7 cells, whereas little or no influence was observed on p53 protein of the two mutant p53 cell lines. However, a significant down-regulation of Mdm2 at protein and mRNA levels was observed in these three cell lines following ADR treatment. Moreover, the decrease of Mdm2 was in both a dose- and time-dependent manner. It is interestingly noted that 5 microM is a critical dose for significant down-regulation of the Mdm2 protein. Selected proteasome inhibitors did not rescue the ADR-caused decline in the expression of Mdm2 protein. Therefore, our present results reveal that ADR can induce a down-regulation of Mdm2 via a p53-independent pathway in human cancer cells and the ubiquitin-proteasome degradation mechanism may not be involved in the decreased expression of Mdm2 protein.
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PMID:P53-independent down-regulation of Mdm2 in human cancer cells treated with adriamycin. 1077 10

The anti-neoplastic properties of an Selenium compound were studied in vitro on several tumor cell lines: Breast (MCF-7, MCF-10, SKBR-3, BCAP37), Lung (RH2), Prostate (LNCap and PC-3), Colon (T84, Caco-2), Small Intestine (HCF8), and Liver (HepG2). We also examined additive or synergistic effect of Selenium in combination with standard anti-cancer drugs, Adriamycin (Doxorubicin) and Taxol. The effect of Selenium was assessed by apoptosis; DNA synthesis; growth rate by MTT assay; uptake of amino acid MeAIB by System A; and morphological changes. Our results demonstrate that MCF-7 and SKBR-3 showed increase in apoptosis as measured by DNA fragmentation and increase in "rounded" cells and membrane "blebbing", decrease in MeAIB uptake, and decrease in DNA synthesis. These changes were Selenium dose dependent with optimal inhibition at Selenium concentration between 4 and 40 ng/ml after 72 hrs of treatment. Similar observations were made with RH2, HCF8, Caco-2, and HepG2 cells. In contrast, LNCap, PC-3, and T-84 were not significantly affected by Selenium. However, addition of Adriamycin or Taxol in combination with Selenium caused small but significant inhibition of prostate cancer cells LNCap and PC-3. Addition of chemotherapeutic agents either Taxol or Doxorubicin with Selenium caused further inhibition of MCF-7, SKBR-3, RH2, HCF8, and HepG2 cells. In conclusion, Selenium has a significant anti-neoplastic effect on breast, lung, liver, and small intestinal tumor cells. Supplementation of Selenium enhanced chemotherapeutic effect of Taxol and Doxorubicin in these cells beyond that seen with the chemotherapeutic drugs used alone. These in vitro studies on several cancer cell lines suggest a potential benefit of Selenium-enhancement of anticancer effects other systems, and therefore offer further relevance to clinical trials efforts.
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PMID:Effect of selenium in combination with Adriamycin or Taxol on several different cancer cells. 1092 49

Doxorubicin (Dox) can provide some stabilization in prostate cancer; however, its use is limited because of systemic toxicities, primarily cardiotoxicity and immunosuppression. The administration of a prodrug of doxorubicin, designed to permit selective activation by the tumor, would reduce general systemic exposure to the active drug and would thereby increase the therapeutic index. Prostate specific antigen (PSA) is a serine protease with chymotrypsin-like activity that is a member of the kallikrein gene family. PSA's putative physiological role is the liquefaction of semen by virtue of its ability to cleave the seminal fluid proteins semenogelins I and II. Serum PSA levels have been found to correlate well with the number of malignant prostate cells. The use of a prodrug which is cleaved by the enzyme PSA in the prostate should in principle produce high localized concentrations of the cytotoxic agent at the tumor site while limiting systemic exposure to the active drug. Cleavage maps following PSA treatment of human semenogelin were constructed. Systematic modification of the amino acid residues flanking the primary cleavage site led to the synthesis of a series of short peptides which were efficiently hydrolyzed by PSA. Subsequent coupling of selected peptides to doxorubicin provided a series of doxorubicin-peptide conjugates which were evaluated in vitro and in vivo as targeted prodrugs for PSA-secreting tumor cells. From these studies we selected Glutaryl-Hyp-Ala-Ser-Chg-Gln-Ser-Leu-Dox, 27, as the peptide-doxorubicin conjugate with the best profile of physical and biological properties. Compound 27 has a greater than 20-fold selectivity against human prostate PSA-secreting LNCaP cells relative to the non-PSA-secreting DuPRO cell line. In nude mouse xenograft studies, 27 reduced PSA levels by 95% and tumor weight by 87% at a dose below its MTD. Both doxorubicin and Leu-Dox (13) were ineffective in reducing circulating PSA and tumor burden at their maximum tolerated doses. On the basis of these results, we selected 27 for further study to assess its ability to inhibit human prostate cancer cell growth and tumorigenesis.
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PMID:The synthesis of a prodrug of doxorubicin designed to provide reduced systemic toxicity and greater target efficacy. 1170 23

Current therapy for advanced prostate cancer is largely based on androgen deprivation and is mostly palliative because all patients eventually relapse with androgen-independent disease. Doxorubicin (Dx), an anthracycline used commonly as a chemotherapeutic agent in relapsed prostate cancer, is a strong inducer of p53 expression and p21(CIP1/WAF1) (p21) transactivation. Previous reports suggest that p21 may have a role in the modulation to chemotherapy-induced apoptosis, prostate cancer progression and androgen regulation. In order to investigate if p21 has a pro-survival role in the response of prostate cancer cells to cellular stress, we exposed two androgen-regulated human prostate cancer cell lines (MDA PCa 2b and LNCaP) to Dx and growth factor withdrawal. We then studied expression of p53 and p21, cell-cycle kinetics and apoptosis. We have found that p53 protein accumulated in a dose- and time-dependent manner after Dx treatment, while p21 expression increased over time with low but decreased with high Dx doses. Apoptosis occurred in parallel with p21 down-modulation. Dx treatment of p53 knockout cells demonstrated that p21 induction was strictly p53 dependent. Reduction of p21 levels in prostate cancer cells with an antisense p21 adenovirus resulted in sensitization to Dx and accelerated onset of apoptosis in response to growth factor withdrawal. The evidence presented here also suggests that caspase activation mediates the apoptosis in this system and supports that p21 may modulate the threshold of apoptosis in prostate cancer. These observations may thus provide implications onto the integration of chemotherapy and androgen ablation.
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PMID:p21 modulates threshold of apoptosis induced by DNA-damage and growth factor withdrawal in prostate cancer cells. 1215 46

A single centre phase II study was conducted to determine the toxicity and activity of Caelyx in hormone refractory metastatic prostate cancer. Doxorubicin is known to be active in this setting and liposomal encapsulation may enhance its therapeutic efficacy and also reduce toxicity. Fourteen patients with hormone refractory metastatic prostate cancer were treated with CaelyxTM 50 mg/m2 once every four weeks. All patients had radiologically proven bone metastases and three also had soft tissue metastatic disease. All patients were evaluable for toxicity and response was assessable in thirteen cases. Three PSA responses were documented in patients with non-measurable disease. No patient had an objective response in measurable disease. The commonest toxicity was cutaneous and this was dose limiting in two patients. Gastrointestinal upset was frequent but generally mild. One patient died shortly after an episode of neutropaenic sepsis with associated grade 3 mucositis following his third cycle of chemotherapy. We confirmed the toxicity profile of Caelyx but its modest antitumour efficacy in this group of patients suggests little promise for future study in metastatic prostate cancer.
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PMID:A phase II study of caelyx (liposomal doxorubicin) in metastatic carcinoma of the prostate: tolerability and efficacy modification by liposomal encapsulation. 1220 96

Overexpression of Bcl-xL, an anti-apoptotic member of the Bcl-2 family, negatively correlates with the sensitivity of various cancers to chemotherapeutic agents. We show here that high levels of expression of Bcl-xL promoted apoptosis of cells treated with an antisense oligonucleotide (5'Bcl-x AS) that shifts the splicing pattern of Bcl-x pre-mRNA from the anti-apoptotic variant, Bcl-xL, to the pro-apoptotic variant, Bcl-xS. This surprising finding illustrates the advantage of antisense-induced modulation of alternative splicing versus down-regulation of targeted genes. It also suggests a specificity of the oligonucleotide effects since non-cancerous cells with low levels of Bcl-xL should resist the treatment. 5'Bcl-x AS sensitized cells to several antineoplastic agents and radiation and was effective in promoting apoptosis of MCF-7/ADR cells, a breast cancer cell line resistant to doxorubicin via overexpression of the mdr1 gene. Efficacy of 5'Bcl-x AS combined with chemotherapeutic agents in the PC3 prostate cancer cell line may be translated to clinical prostate cancer since recurrent prostate cancer tissue samples expressed higher levels of Bcl-xL than benign prostate tissue. Treatment with 5'Bcl-x AS may enhance the efficacy of standard anti-cancer regimens and should be explored, especially in recurrent prostate cancer.
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PMID:Cellular response to an antisense-mediated shift of Bcl-x pre-mRNA splicing and antineoplastic agents. 1238 25

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL/Apo2L) can induce receptor-mediated apoptosis in prostate cancer cell lines that have been co-treated with the chemotherapeutic agent doxorubicin (Voelkel-Johnson C, et al. Cancer Gene Therapy 2002; 9:164-172). In this study, we report that pretreatment with doxorubicin is sufficient to sensitize cells to TRAIL. To identify possible targets of doxorubicin, we analyzed levels of several Bcl-2 family members, TRAIL receptors and the anti-apoptotic protein c-FLIP. Doxorubicin did not affect steady state levels of Bax, Bcl-2 and Bcl-X(L) in the majority of the prostate cancer cell lines. TRAIL receptor mRNAs (DR4, DR5, and DcR2) were induced by doxorubicin but these changes were not reflected at the protein level. In contrast, in response to doxorubicin, levels of c-FLIP, particularly FLIP(S), decreased in all cell lines tested. The decrease in c-FLIP(S) correlated with onset and magnitude of caspase-8 and PARP cleavage in PC3 cells. In two TRAIL resistant cell lines, DU145 and LNCaP, treatment with TRAIL alone resulted in processing of c-FLIP(L) and initiated abortive caspase-8 proteolysis. TRAIL treatment did not affect levels of c-FLIP(S) in Du145 and LNCaP cells and did not result in PARP cleavage. Therefore, our results suggest that doxorubicin- mediated down regulation of c-FLIP(S) predisposes cells to TRAIL-induced apoptosis.
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PMID:Doxorubicin pretreatment sensitizes prostate cancer cell lines to TRAIL induced apoptosis which correlates with the loss of c-FLIP expression. 1249 82


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