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)

Potent synthetic analogs of gonadotropin-releasing hormone produce parodoxical antireproductive effects when administered chronically. These compounds are minimally toxic and may exhibit no plateau of the dose-response curve even at very high doses. These considerations served as the basis for our systematic evaluation of [D-leucine6-desarginine-glycine-NH2(10)]gonadotropin-releasing hormone (GnRH-A) proethylamide in the very high dose range (i.e., 10-fold larger amounts than previously used). In rats given the analog for 12 wk, prostate, testis, and seminal vesicle weights were suppressed to a greater extent with 200 micrograms q.d. than with 40 micrograms q.d. (P less than 0.01 prostate, less than 0.01 testis, less than 0.01 seminal vesicles), indicating dose-response effects in the very high dose range. 200 micrograms of [D-Leu6-des-Gly-NH2(10]-GnRH-A consistently suppressed leutinizing hormone (LH) values at 6 and 12 wk (basal 71 +/- 9.5; 6 wk 34 +/- 3.8; 12 wk 28 +/- 5 ng/ml) whereas 40 micrograms suppressed LH variably (basal 33 +/- 3.8; 6 wk 17 +/- 3.9; 12 wk 32 +/- 5.2). Testosterone fell to 15 +/- 2.4 and 19 +/- 2.0 ng/100 ml in response to 200 micrograms q.d. and to 27 +/- 6.4 and 22 +/- 7.4 ng/100 ml with the 40-micrograms dose. These findings in the rodent prompted treatment of stage D prostate cancer patients with similarly high doses of [D-Leu6-des-Gly-NH2(10)]-GnRH-A. After treatment for 11 wk with 1,000 or 10,000 micrograms/d of the analog, testosterone and dihydrotestosterone levels transiently rose and then fell into the surgically castrate range (testosterone 19 +/- 4.4 ng/100 ml [D-Leu6-des-Gly-NH2(10)]-GnRH-A vs. surgically castrate 11 +/- 0.9 ng/100 ml, P = NS; dihydrotestosterone 15 +/- 1.7 ng/100 ml GnRH-A vs. surgically castrate 15 +/- 4.1 ng/100 ml. P = NS). However, unlike the chronic stimulatory effect on the pituitary at lower doses, very high dose therapy resulted in profound suppression of plasma and urine LH. Plasma levels fell to the limit of assay detectability, whereas the more sensitive urinary assay detected prepubertal levels of excretion (i.e., 64 +/- 8.4 mlU/h). The highly sensitive rat interstitial cell testosterone bioassay for LH also demonstrated a marked decline in LH to undetectable levels in 17/19 subjects. Clinical results with [D-Leu6-des-Gly-NH2(10)]-GnRH-A simulate those achieved by surgical castration in men with prostatic cancer as suggested by available preliminary data.
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PMID:Effect of very high dose D-leucine6-gonadotropin-releasing hormone proethylamide on the hypothalamic-pituitary testicular axis in patients with prostatic cancer. 640 25

Orchiectomy or chronic administration of the gonadotropin releasing hormone agonistic analogue D, Ser (TBU)6, des Gly-NH2(10) ethylamide (HOE 766) were employed as therapeutic maneuvers in 25 patients with advanced prostatic carcinoma. HOE 766 administration effectively suppressed plasma testosterone to castrate levels that persisted for as long as treatment continued. Surgical and medical castration resulted in a significant decrease in prostatic size; this became evident earlier for surgically than medically treated patients (P less than .05), but no difference existed after the third month of treatment. Symptoms and signs of prostatism improved in practically all the patients. Among patients with stage D2 disease, there was an improvement in five as far as bone radiological assessment was concerned. Alkaline phosphatase levels did not show appreciable changes in patients showing objective stable disease or partial response according to National Prostatic Cancer Project criteria. Radioimmunoassayable prostatic acid phosphatase levels became normal in two of two stage C, five of five stage D1, and eight of seventeen patients with stage D2 disease, a rise in prostatic acid phosphatase (PAP), in alkaline phosphatase, and deterioration in bone radiology were associated with clinical evidence of relapse; this occurred despite persistently low levels of plasma testosterone. Serum thyroxine, cortisol, and prolactin levels remained unchanged following orchiectomy or chronic administration of HOE 766. Practically all patients complained of hot flashes and experienced a decrease in libido and potency, but none developed gynecomastia or thromboembolic episodes. The data indicate that HOE 766 can be used safely as an alternative to castration or estrogens for the treatment of patients with androgen-dependent prostatic cancer.
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PMID:Gonadotropin-releasing hormone agonistic analogues in the treatment of advanced prostatic carcinoma. 641 29

We have used the paradoxical antigonadal effects of LHRH agonists as a chemical castration in advanced prostatic cancer. We report early results of a phase II study on the clinical efficacy of the LHRH agonist D-Ser (TBU)6, des-Gly-NH2(10) LHRH administered to patients with stage D prostatic carcinoma. Following dose-range finding studies using either intranasal (IN) (200 micrograms twice/day or 500 micrograms twice/day) or subcutaneous (SC) administration (50 micrograms once/day, we developed a sequential combination of SC (500 micrograms three times/day for seven days) and IN regimen that was administered for 3 to 16 months to a group of 23 patients with stage D prostatic carcinoma. Initiation of therapy was associated with a clinical flare in one patient during the first week of treatment. Mean serum testosterone levels were already decreasing at one week and remained inhibited to levels inferior to 1 ng/ml after the first four weeks of treatment. Overall assessment shows that within the first six months of treatment, 26% patients were improved, 39% were stabilized, and 35% were nonresponders. Fourteen patients were followed during the next six months: 29% continued to respond, 29% escaped, 21% remained stable, and 21% were nonresponders. Histologic studies from castrated patients showed changes in spermatogenesis correlating to the degree and duration of suppression of testicular steroidogenesis without signs of toxicity. Preliminary observations on the combination of the pure antiandrogen RU 23908 with Buserelin (n = 5) or castration (n = 3) suggest that the addition of an antiandrogen does not seem to improve the patients nonresponding to other hormonal suppressive therapy (Buserelin) administered before (n = 3) or concomitantly with the antiandrogen (n = 2). Three relapsing castrate patients responded to the antiandrogen, but the response was temporary in two (eight to nine months of therapy). No side effects other than hot flashes and decreased potency are related to LHRH agonist alone or to the low-dose antiandrogen. Multicenter trials will be necessary to delineate the place of LHRH agonist alone or LHRH agonist combined with an antiandrogen in the treatment of prostatic cancer.
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PMID:Preliminary results on the clinical efficacy and safety of androgen inhibition by an LHRH agonist alone or combined with an antiandrogen in the treatment of prostatic carcinoma. 641 32

Following the studies of Huggins and colleagues in 1941, the hormonal treatment of prostatic cancer has been aimed at neutralizing the influence of testicular androgens through surgical castration or the administration of high doses of estrogens. These two approaches cause a temporary improvement in 60 to 70% of advanced prostatic cancer. However, castration is not always well accepted and high doses of estrogens are frequently accompanied by lethal cardiovascular side effects. Following our observation that treatment with LHRH agonists causes a blockage in the biosynthesis of testosterone by the testis accompanied by a marked reduction in prostatic weight in the rat, the possibility was opened for a new approach in the treatment of prostatic cancer. Fortunately, among all species studied, man is the most sensitive to the inhibitory effect of LHRH agonists on testicular androgen biosynthesis and near-medical castration can be easily achieved without secondary effects other than those related to low androgen levels. Following long-term studies in the rat which have shown that the inhibitory effect of LHRH agonists is markedly potentiated by simultaneous administration of a pure antiandrogen, a study using the LHRH agonist [D-Ser(TBU)6, des-Gly-NH2(10)] LHRH ethylamide (HOE-766) and the pure antiandrogen RU-23908 was performed in men with advanced prostatic cancer. The combined treatment with the LHRH agonist and the antiandrogen in 37 patients not previously treated caused a positive objective response in 97% of cases while, previously, partial hormonal treatment achieved through castration or high doses of estrogens caused a positive response in 60 to 70% of patients. The serum levels of prostatic acid phosphatase (PAP) were decreased to 40% of control as early as four days after starting combined hormonal therapy. By contrast, in patients previously treated with estrogens or castrated, complete neutralization of adrenal androgens by the antiandrogen led to a much lower rate of positive response ranging from 25 to 55%. In patients previously treated, there is thus a predominance of tumor cells insensitive to androgens. An additional important finding in this study is that the administration of the antiandrogen prevents the flare-up of the disease frequently observed when LHRH agonists are administered alone.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[New approach in the treatment of prostatic cancer: combined use of a LHRH agonist and an androgen antagonist]. 642 7

The clinical efficacy of (D-Leu6)-des Gly-NH2(10)-LH X RH ethylamide (Leuprolide) against prostatic cancer was evaluated at the end of twelve weeks of administration of a daily dose of 20 mg subcutaneous injection to 22 patients with prostatic cancer. Of these 22 patients, 19 were previously non-treated and 3 had reactivated cancer. Complete regression was obtained in all patients with stage B or C cancer. Also, in 5 out of 12 previously non-treated patients with stage D cancer, Leuprolide administration proved to be effective for controlling prostatic cancer. However, Leuprolide therapy produced only stable effects at best in 3 patients who had reactivated cancer. It has no side effect and should be recommended as a drug of first choice in the treatment of previously non-treated prostatic cancer. It can be assumed from the present studies that the efficacy of this agent against prostatic cancer is mainly the result of its inhibitory effect on hypothalamo-pituitary testicular system, i.e., a medical castration effect.
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PMID:[Clinical efficacy of (D-Leu6)-des Gly-NH2(10)-LHRH ethylamide against prostatic cancer]. 643 16

In order to block the influence of androgens from all sources on the growth of prostatic cancer, we have used a new hormonal therapy based on medical castration achieved with the potent LHRH agonist [D-Ser(TBU)6, des-Gly-NH2(10)]LHRH ethylamide (HOE-766) combined with the administration of a pure antiandrogen that neutralizes the action of adrenal androgens as well as those still secreted in low amounts by the testis during LHRH agonist treatment. This study was performed in ten patients with advanced prostatic carcinoma (9 at stage D2 and one at stage C). Bone pain, prostatism and general well-being were 60 to 90% improved within one month after starting treatment in all patients. After 2 months of treatment, minimal bone pain remained only in one patient who was originally bedridden. Bone scanning showed a 70 to 90% decrease in uptake after 3 to 5 months of treatment in the patients studied. Acid phosphatase levels were 60 to 90% reduced after 2 months of treatment in 3 out of the 4 patients who had elevated levels before therapy. Marked objective and subjective improvement was thus rapidly observed in 9 out of 10 patients treated with the combined therapy, while, in the other patient at stage C, subjective improvement could be documented. Although preliminary, this study indicates that a combined hormonal therapy which neutralizes all androgenic influences on peripheral tissues is of potential benefit in prostatic cancer. Moreover, the ease of application as well as the lack of secondary effects of the present approach should make possible its use early in the disease and should thus minimize the development of metastases and androgen-resistant cell clones. Randomized prospective studies on this potentially beneficial therapy are warranted.
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PMID:New hormonal therapy in prostatic carcinoma: combined treatment with an LHRH agonist and an antiandrogen. 681 1

Combination therapy with the antiandrogen flutamide and the luteinizing hormone-releasing hormone (LHRH) agonist [D-Trp6, des-Gly-NH2(10)] LHRH ethylamide or orchiectomy was administered to 268 patients with previously untreated metastatic stage D2 prostate cancer for an average of 1,191 d (3.26 y). Only 17 of the 268 evaluable patients (6.5%) showed no objective positive response to the combination therapy assessed according to the National Prostatic Cancer Project objective criteria of response. The median duration of the disease-free response was 2.23 y and median overall survival was 3.58 y. The median survival for patients with only 1-5 bone metastases was not yet reached at 8 y, but for patients with 6-10 bone lesions, 11-40 bone lesions, and multiple bone metastases (superscan), median survival was markedly reduced to 3.56, 2.36, and 1.76 y, respectively. Analysis of patients according to general symptomatology, pain, and performance status showed median survivals of 5.47, 2.71, and 2.1 y for minimal, moderate, and severe symptoms, respectively. The present data demonstrate that administration of combination therapy to stage D2 prostate cancer patients having 1-5 bone metastases adds a minimum of 4.4 y of good quality life compared with patients whose disease is slightly more advanced. Our findings clearly demonstrate the major importance of starting combination therapy as soon as possible after diagnosis of metastatic prostatic cancer.
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PMID:Major advantages of "early" administration of endocrine combination therapy in advanced prostate cancer. 801 54

Cytotoxicity indicated by increased release of prelabeled 51chromium (51Cr) and lactate dehydrogenase (LDH) was studied in human prostate cancer and melanoma cells in cell culture following irradiation or exposure to several injurious substances. These changes were compared to those observed in bovine aortic endothelial cells (BAEC) subjected to identical treatments. Further, the effect of irradiation on plasminogen activator (PA) secretion from prostate cancer cells, and the effect of glycine on radiation-induced cytotoxicity in BAEC were also investigated. Radiation, lipopolysaccharide and xanthine/xanthine oxidase stimulated no release of 51Cr or LDH from tumor cells, while these treatments induced a dose- and time-related loss of those cytotoxic indicators from BAEC. Protease, elastase and Triton X-100 incited loss of 51Cr and LDH from all three cell types. Radiation, lipopolysaccharide and xanthine/xanthine oxidase have been shown to cause cell injury via a common pathogenic pathway of oxidant generation. Tumor cells appear quite resistant to oxidant stress. Cell damage precipitated by protease, elastase and Triton probably involves hydrolysis of proteins and phospholipids in the cell membrane, leading to an increased leakage of intracellular proteins such as LDH and those bound with 51Cr. Radiation caused a dose- and time-related reduction in the secretion of PA from prostate cancer cells. PA is alleged to play a role in tumor metastasis; the reduced secretion could be another beneficial effect of radiation, in addition to interruption of cell proliferation, in the impediment of tumor growth and spread. Glycine diminished cytotoxic injury of BAEC inflicted by radiation. This amino acid may prove useful in offering a degree of protection of normal tissue against radiation associated side-effects.
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PMID:Injury-specific cytotoxic response of tumor cells and endothelial cells. 868 34

Progression of prostate cancer during endocrine therapy is a major clinical problem, the molecular mechanisms of which remain poorly understood. Amplification of the androgen receptor (AR) gene was recently described in recurrent prostate carcinomas from patients who had failed androgen deprivation therapy. To evaluate the hypothesis that amplification of the AR gene is a cause for the failure of androgen deprivation therapy in prostate cancer, we studied whether AR amplification leads to gene overexpression, whether the amplified AR gene is structurally intact, and whether tumors with AR amplification have distinct biological and clinical characteristics. Tumor specimens were collected from 54 prostate cancer patients at the time of a local recurrence following therapy failure. In 26 cases, paired primary tumor specimens from the same patients prior to therapy were also available. Fifteen (28%) of the recurrent therapy-resistant tumors, but none of the untreated primary tumors, contained AR gene amplification as determined by fluorescence in situ hybridization. According to single-stranded conformation polymorphism analysis, the AR gene was wild type in all but one of the 13 AR amplified cases studied. In one tumor, a presumed mutation in the hormone-binding domain at codon 674 leading to a Gly --> Ala substitution was found, but functional studies indicated that this mutation did not change the transactivational properties of the receptor. AR amplification was associated with a substantially increased level of mRNA expression of the gene by in situ hybridization. Clinicopathological correlations indicated that AR amplification was most likely to occur in tumors that had initially responded well to endocrine therapy and whose response duration was more than 12 months. Tumors that recurred earlier or those that showed no initial therapy response did not contain AR amplification. The median survival time after recurrence was two times longer for patients with AR amplification in comparison to those with no amplification (P = 0.03, Willcoxon-Breslow test). In conclusion, failure of conventional androgen deprivation therapy in prostate cancer may be caused by a clonal expansion of tumor cells that are able to continue androgen-dependent growth despite of the low concentrations of serum androgens. Amplification and the increased expression of a wild-type AR gene may play a key role in this process.
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PMID:Androgen receptor gene amplification: a possible molecular mechanism for androgen deprivation therapy failure in prostate cancer. 900 May 75

Opioid agonists (ethylketocyclazocine, etorphine, [D-Ala2,D-Leu5]enkephalin (DADLE), [D-Ala2, N-Me-Phe4-Gly-ol]enkephalin (DAGO), [D-Ser2,Leu5]enkephalin-Thr6 (DSLET) and morphine were found to inhibit the proliferation of human prostate cancer cell lines (LNCaP, DU145, and PC3), in a dose-dependent manner. The 50% inhibitory concentrations (IC50) were in the picomolar range. In many cases, this effect was antagonized by the general opioid antagonist, diprenorphine, indicating the existence of specific opioid binding sites. Saturation binding experiments with selective ligands and effectors showed no opioid sites on the LNCaP cell line, kappa1 and mu sites on the PC3 cell line, and kappa1, kappa3 and mu sites on the DU145 cell line. In other cases, the opioid effect was not antagonized by diprenorphine, indicating that the action of opioids might be mediated through other membrane receptors. Furthermore, casomorphin peptides, issued from bovine alpha- (alpha-casein-90-95 and alpha-casein-90-96) and beta-caseins (beta-casomorphin and beta-casomorphin-1-5), and human alphaS1-casein (alphas -casomorphin and alphaS1-casomorphin amide) inhibited cell proliferation of human prostate cell lines, also by a mechanism partly involving opioid receptors. As opioid neurons can be found in the prostate gland, and casomorphin peptides might reach the gland through the general circulation, the above findings indicate a putative role of opioids in prostate cancer cell growth.
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PMID:Opioid alkaloids and casomorphin peptides decrease the proliferation of prostatic cancer cell lines (LNCaP, PC3 and DU145) through a partial interaction with opioid receptors. 936 81


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