Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bleomycin, a chemotherapeutic antibiotic agent, was radio-iodinated by the ICI and chloramine-T methods; the radiochemical stabilities and pharmacokinetics of the two I-bleomycins in tumor-bearing mice were compared. The ICI preparation was more stable with respect to deiodination in vitro. Both products were sufficiently stable in vivo that high body background due to free isotope, a disadvantage of 111In- and 99mTc-bleomycin, was not encountered. Tumor uptake of the ICI preparation was constant from 2 to 24 hrs., and the tumor/blood ratio increased with time; with chloramine-T, this ratio decreased, and was less than that for ICI. The two preparations are chemically and biologically different; the ICI product is the superior tumor radiodiagnostic agent.
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PMID:Comparison of I-bleomycin prepared by two methods stability and pharmacokinetics in tumor-bearing mice. 6 31

The effect of prolactin in supporting the growth of 7, 12-dimethylbenz(a)anthracene-induced mammary tumor in adult female Sprague-Dawley rats was investigated when estrogen receptors were blocked by the nonsteroidal antiestrogen, Tamoxifen, ICI 46,474. Following an oophorectomy-induced remission, perphenazine, which stimulates endogenous prolactin release, was able to restore tumor growth whether or not Tamoxifen was added. A second course of perphenazine treatment, instituted after the tumors were allowed to shrink, was again effective in stimulating tumor growth. After a regression in tumor size induced by oophorectomy and daily administration of Tamoxifen, perphenazine was able to restore original tumor size despite continued treatment with Tamoxifen. In intact rats, after regression was obtained by daily administration of Tamoxifen and the prolactin inhibitor, lergotrile mesylate, perphenazine induced tumor growth when the latter was discontinued, even though Tamoxifen was continued for 50 days. Estrogen receptors measured at the time of maximum stimulation by perphenazine were undetectable. On the other hand, estradiol did not stimulate tumor growth when serum prolactin was depressed to undetectable levels by lergotrile. These results indicate that prolactin supports the growth of 7, 12-dimethylbenz(a)anthracene-induced rat mammary tumor and that estrogen receptors are not required under these conditions.
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PMID:Predominant role of prolactin in stimulating the growth of 7, 12-dimethylbenz(a)anthracene-induced rat mammary tumor. 19 Nov 82

In three experiments, chloroform was administered to mice by gavage in a toothpaste base or in arachis oil, in doses up to 60 mg/kg/d on 6 days/wk for 8 wks. Control groups were left untreated or given vehicle only. In general, there were more survivors in chloroform-treated groups than in the controls. In the case of the males of three strains (C57BL, CBA and CF/1), treatment was associated with no adverse affect on the incidence of any type of neoplasm or any other parameter. In the males but not the females of a fourth strain (ICI) and in doses of 60 mg/kg/d but not of 17 mg/kg/d, exposure to chloroform in toothpaste base as a vehicle was associated with increased incidence of epithelial tumours of the kidney. A more pronounced effect of the same kind was seen in mice given 60 mg CHCl3/kg/d in an archis oil vehicle. This treatment was also associated with a higher incidence and severity of non-neoplastic renal disease. The mechanisms underlying the peculiar strain- and sex-specific susceptibility of ICI male mice to develop renal tumours when exposed to chloroform remain obcure; spontaneous renal tumours were also seen in vehicle control mice and possible ways in which this tendency may be enhanced by chloroform treatment are discussed. At the dose levels tested, namely 113 and 400 times average human exposure levels from the use of toothpaste (with 3.5 percent chloroform content), no adverse affect was seen in the liver and there was no increased incidence of liver tumours even in the higher liver tumour susceptible CBA strain. At the 17 mg CHCl3/kg/d level, equivalent to 113 times average human exposure from toothpaste use, no excess of renal tumours was seen even in males of the peculiarly susceptible ICI strain.
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PMID:Safety evaluation of toothpaste containing chloroform. I. Long-term studies in mice. 42 36

Tamoxifen (ICI 46474), an antiestrogen, was given to 89 selected patients with stage IV breast cancer at a dose of 20 mg orally every 12 hours. Forty-seven percent of the patients had objective tumor regression averaging 11+ months with 25 of 42 women still in remission. In the first 39 patients where the minimum follow-up period is 16 months the average duration of remission is more than 15 months with 8 of 19 patients still in remission. These results are approaching those of surgical hypophysectomy, where, in our experience the average remission lasts about 18 months. Thus, Tamoxifen is a highly effective antitumor agent and is probably the initial treatment of choice for women with hormone responsive breast cancer. Antiestrogen induced objective remissions in 5 of 19 patients who had previously responded to surgical hypophysectomy, and 5 additional patients showed no progression of disease lasting 15+ months. Estradiol and estrone were detectable in the serum of these patients whereas, prolactin and growth hormone were not detectable. Thus, antiestrogen can induce remissions in some patients in the absence of the pituitary gland, and this constitutes additional palliation and provides evidence that estrogens can directly stimulate tumor growth. Four of 7 patients who obtained remissions from Tamoxifen obtained further improvement from hypophysectomy, and 1 of 8 patients who failed to benefit from antiestrogen improved after hypophysectomy. These results suggest that prolactin and growth hormone may also play a role in stimulating tumor growth in some patients.
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PMID:Treatment of breast cancer with antiestrogen: approach to medical hypophysectomy? 61 66

This paper reviews the antiestrogenic and antitumor properties of tamoxifen (NSC-180973; ICI-46474) in the rat. In classic tests for antiestrogenic activity, tamoxifen inhibits the actions of estradiol in the rat uterus and vagina. At the cellular level, tamoxifen inhibits estrogen binding to cytoplasmic estrogen receptors, but although estrogen-receptor units are translocated to the nucleus DNA synthesis does not occur. It is suggested that tamoxifen competes for estrogen receptors in the cytoplasm and the false messenger units block the nuclear acceptors which are normally activated by estradiol-estrogen receptor complexes thereby provoking DNA synthesis. Tamoxifen inhibits the growth of some 7.12-dimethylbenz(a)anthracene-induced rat mammary tumors whereas others continue to grow. Estrogen-stimulated rises in plasma prolactin are only partially inhibited by tamoxifen although at the tumor level, tamoxifen completely blocks estrogen binding. There is a linear correlation (P less than 0.01) between estrogen-receptor levels in tumor biopsies before therapy and tumor responses to 3 weeks of tamoxifen treatment (50 mug/day) i.e., tumors with low levels of estrogen receptors do not respond to therapy whereas tumors with higher levels of estrogen receptors regress. It is suggested that tamoxifen antagonizes the actions of estrogen at the tumor level by blocking the estrogen-receptor mechanism thereby producing tumor regression. Therefore, estrogen-receptor measurements in tumor biopsies before therapy may be a useful predictive test for the tumor response to tamoxifen treatment.
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PMID:Antiestrogenic and antitumor properties of tamoxifen in laboratory animals. 82 17

Previous studies from this laboratory have described that LNCaP prostate tumor cells contain an androgen receptor (AR) with a point mutation in the steroid-binding domain (codon 868, Thr to Ala). This defect leads to a change in specificity of the AR. Estrogens, progestagens, and some anti-androgens (e.g., cyproterone acetate, hydroxyflutamide, nilutamide) stimulate LNCaP cell growth rate through the AR. The present studies indicate that not all anti-androgens showed agonistic effects with the mutated receptor. The growth rate of LNCaP cells did not increase with the anti-androgen ICI 176334, nor could this compound increase transcription activation of the reporter gene construct via the mutant receptor in a cotransfection system [HeLa cell cotransfection system with an androgen-regulated reporter gene construct (pG29G-tk-CAT) and the mutant receptor as trans-vector]. Interaction of the AR of LNCaP cells with heat-shock proteins was studied by isolation of the receptor with a specific monoclonal antibody and characterization of associated proteins. Hsp90, hsp70, and hsp56 were found to coprecipitate with the AR. Incubation of the cells at 37 degrees C with androgen (R1881, 10 nM) or the anti-androgen hydroxyflutamide, prior to receptor isolation, resulted in dissociation of the AR-heat-shock protein complex. This dissociation is paralleled by the transformation to a tight nuclear-binding form of the AR. In contrast, ICI 176334 could not induce a release of heat-shock proteins and did not increase nuclear binding, but inhibited the transformation process induced by R1881.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Anti-androgens and the mutated androgen receptor of LNCaP cells: differential effects on binding affinity, heat-shock protein interaction, and transcription activation. 154 May 95

To evaluate the clinical and prognostic value of prostate-specific antigen (PSA) for the detection of tumor and tumor growth after therapy, 520 sera from 246 patients with prostatic carcinoma, 990 sera from patients with BPH, and 1,488 sera from patients with other urological diseases were analyzed. The values ranged from 0.1 to 1,828.9 ng/ml. 51% of all values were about 2.5 ng/ml, and 76.8% of all values about 10 ng/ml. The commercial recommendation for the cutoff values is 2.5 ng/ml (IBL, FRG). In patients with benign prostatic hypertrophy this cutoff means 61% false-positive results, which makes the test highly sensitive but unspecific. In prostatic carcinoma patients this borderline means a false-negative result in 9.75% (24 of 246). By determining the cutoff at 10 ng/ml in our series, a false-negative result appeared in 14.6%. Therefore a plea is made for the 10-ng/ml cutoff. In follow-up studies a marked decline in PSA values after transurethral resection or antiandrogen therapy (orchiectomy/Zoladex/ICI/flutamide, Essex). Generally, the greater the PSA levels the more advanced the stage of disease. These data suggest that PSA may be a useful adjuvant marker for monitoring tumor growth in patients with regionally confined tumor.
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PMID:Prostate-specific antigen in prostatic carcinoma. 169 55

Two female patients with desmoid tumors (aggressive fibromatosis) showed tumor regression after endocrine therapy. In one patient, tumor response to tamoxifen has been maintained over several years of treatment. In the second patient, who had inoperable mesenteric fibromatosis, the tumor progressed on tamoxifen but regressed after treatment with Zoladex (goserelin acetate, ICI, Melbourne, Australia) and medroxyprogesterone acetate (MPA). To the authors' knowledge this is the first report of the use of Zoladex in the treatment of desmoid tumors. This review of the literature reveals that the biology of this disease is related to the endogenous hormonal environment and that estrogen receptors have been documented in desmoid tumors. Thirty-five cases are identified where endocrine agents have been employed, with a response rate of 51%. Furthermore, tumors may respond to second-line hormonal therapy after failing to respond to initial endocrine treatment. Endocrine treatments have also been used in other disorders of fibroblastic origin. The authors recommend that endocrine treatment be employed in inoperable desmoid tumors or where there has been postsurgical recurrence. In addition, the role for endocrine therapy in other soft tissue neoplasms should be determined.
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PMID:Endocrine therapy for desmoid tumors. 183

Heterocyclic para-aminobenzoate modifications of 2-desamino-2-methyl-5,8-dideazafolic acid and a series of its N10-substituted analogs have produced a number of interesting compounds that have enabled a deeper understanding of the biochemical events required for activity in this class of antimetabolite. There is a relationship that has become apparent between compound potency and both uptake via the reduced-folate carrier and FPGS substrate activity. Rapid cellular uptake and metabolism of polyglutamate forms that are approximately 100-fold more potent as inhibitors of TS can translate a modest TS inhibitor such as ICI D1694 into a very potent inhibitor of cell growth (approximately 500- and approximately 10-fold more potent than CB3717 or ICI 198583, respectively). Polyglutamation may therefore act as an almost essential activation step and ICI D1694 may be highly specific for tumors expressing both the reduced-folate carrier and FPGS. Polyglutamation of folate analogs also leads to drug retention which may play a major role in the pharmacodynamics of TS inhibition by ICI D1694 in vivo. Current studies with 3H-ICI D1694 are aimed at demonstrating metabolism to polyglutamates in tumor cells. The serious toxic limitations of CB3717, i.e., liver and kidney toxicities, are not seen with ICI D1694 reflecting the good water solubility of the drug compared with CB3717. The toxicities observed in mice are however to hematological tissues and are due to its TS inhibitory effects. Thus ICI D1694 may elicit toxicities in man more typical of an antimetabolite than of CB3717. The clinical evaluation of ICI D1694 may further our understanding of the role that metabolism to polyglutamates may have in therapeutic activity.
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PMID:Thymidylate synthase inhibitors: the in vitro activity of a series of heterocyclic benzoyl ring modified 2-desamino-2-methyl-N10-substituted-5,8-dideazafolates. 187 86

The radiation leukemia virus-induced murine Cyc- T lymphoma cell line TL2-9 expressed one homogeneous population of beta 2-adrenoceptors based on competition curves of [125I]cyanopindolol with the specific antagonist ICI 118.551 and three beta-adrenergic agonists. These receptors were uncoupled from adenylate cyclase due to the absence of Gs. The catalytical unit was directly stimulated by MnCl2, forskolin, and even more markedly in the simultaneous presence of both reagents. In contrast, the enzyme was inhibited in the presence of Gpp[NH]p, probably through interaction with Gi. Indeed, this inhibitory effect was constrained by preincubating cells in the presence of pertussis toxin and a 41 kDa protein was specifically ADP-ribosylated in the presence of the toxin. This cell line was therefore analogous to the Cyc- cell line derived from the murine S49 lymphoma cell line. When added to the culture medium, butyrate (2 mM) induced beta 2-adrenoceptors, the expression of these uncoupled receptors depending on protein synthesis, as judged by inhibitory effects of cycloheximide. In contrast, dBcAMP (1 mM) and TPA (tumor-promoting agent phorbol ester) increased the rate of disappearance of beta 2-adrenoceptors. Butyrate, dBcAMP and TPA systematically decreased adenylate cyclase activity. Besides, TPA (but neither butyrate nor dBcAMP) reduced the efficacy of Gpp[NH]p in inhibiting adenylate cyclase, suggesting a proportionately higher alteration of Gi. We conclude that beta 2-adrenoceptors, uncoupled from adenylate cyclase, are regulated independently from the catalytical unit and Gi, in this Cyc- T lymphoma cell line.
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PMID:Divergent regulation of beta 2-adrenoceptors and adenylate cyclase in the Cyc- mouse T lymphoma cell line TL2-9. 198 Feb 64


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