Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The methods for treatment of advanced prostate cancer, based on the agonistic analogs of LH-RH were reviewed. New therapeutic approaches utilizing antagonistic analogs of LH-RH such as SB-75 (Cetrorelix) have been described. Analogs of LH-RH chemically linked to various cytotoxic radicals are also being developed. Combinations of LH-RH agonists or antagonists with superactive somatostatin analogues such as Octastatin (RC-160) or with bombesin/GRP antagonists are being investigated in order to delay or prevent the relapse and improve the therapy for prostate cancer.
 ...
PMID:Present status of agonistic and antagonistic analogs of LH-RH in the treatment of advanced prostate cancer. 136 77

This study was undertaken to establish the presence and characteristics of receptors for [D-Trp6]LH-RH on the membranes of human ovarian cancer. Specific binding of [125I, D-Trp6]LH-RH was found in 29 of 37 (78.4%) ovarian cancers and in 6 of 11 (54.5%) non-malignant human ovaries. Ligand binding was dependent on time and plasma membrane concentration in a fashion expected of a peptide hormone. Saturation, kinetic and displacement data were consistent with the presence of a highly specific, single class of non-cooperative binding site. On the basis of receptors affinity, LH-RH-receptor-positive ovarian cancers could be divided into two groups: high affinity group (Kd=2.71 +/- 0.60 nM; Bmax=0.46 +/- 0.07 pmol/mg membrane protein) comprising 55% of tumors, and low affinity group (Kd=78.0 +/- 19.6 nM; Bmax=9.44 +/- 2.68 pmol/mg membrane protein) which included 45% of tumors. LH-RH antagonist Cetrorelix showed an affinity to LH-RH receptors on ovarian cancers 14 times higher than the agonist [D-Trp6]LH-RH. Using 125I-epidermal growth factor, specific high affinity receptors were also detected in membranes from 13 of 24 (54%) ovarian cancers and 5 of 11 (45%) non-malignant ovaries. The demonstration of LH-RH receptors in human ovarian cancers provides a rationale for the use of therapeutic approaches based on LH-RH analogues in this malignancy. The probable involvement of growth factors in the development of ovarian cancers suggests the merit of trying a combined therapy based on analogs of LH-RH and somatostatin for this carcinoma.
 ...
PMID:Presence and characteristics of receptors for [D-Trp6]luteinizing hormone releasing hormone and epidermal growth factor in human ovarian cancer. 947 84

Reduction in receptors for epidermal growth factor (EGF) in cancers appears to be one of the principal mechanisms through which peptide hormone analogs can inhibit tumor growth. In this study, hamsters with nitrosamine-induced pancreatic cancers were treated for 8 weeks with bombesin/gastrin-releasing peptide (GRP) antagonist RC-3095, somatostatin analog RC-160 or the luteinizing hormone-releasing hormone antagonist Cetrorelix, using sustained delivery systems releasing 20, 35 and 20 microg analog/ day respectively. To establish the pattern of changes in the number and affinity of EGF receptors on tumors, groups of animals were sacrificed at regular intervals during therapy. Chronic treatment with RC-3095 or Cetrorelix resulted in an early (day 10) and sustained reduction (71% or 69% respectively) in EGF receptors on pancreatic tumors. In contrast, RC-160 decreased receptor concentration by 60% only after 20 days. Among the histological characteristics of proliferation, the decrease in argyrophilic nucleolar organizer regions, but not apoptotic and mitotic indices, showed a correlation with the fall in EGF receptors. The concentration of the receptors returned to the control level 4 days after cessation of chronic treatment with RC-3095. The effect of single injections of RC-3095, RC-160 and Cetrorelix on EGF receptors was also investigated. RC-160 decreased the number of EGF receptors on pancreatic cancers by 31% 3 h after administration, but the receptors had returned to normal level at 6 h. RC-3095 and Cetrorelix caused a 67% and 59% decline, respectively, in EGF receptors only 6 h after injection and the concentration of receptors remained low for 24 h. Thus, the pattern of downregulation of EGF receptors in pancreatic cancers appears to depend on the peptide used for therapy. Since the antitumor effect may be the result of the fall in EGF receptors in cancers, information on the time course of changes in these receptors during treatment with these analogs may lead to an improvement in therapeutic regimens.
 ...
PMID:Growth inhibition of experimental pancreatic cancers and sustained reduction in epidermal growth factor receptors during therapy with hormonal peptide analogs. 1048 Mar 36

The use of peptide analogs in the therapy of prostate cancer is reviewed. The preferred primary treatment of advanced androgen-dependent prostate cancer is presently based on the use of depot preparations of LH-RH agonists. This treatment is likewise recommended in patients with rising PSA levels after surgery or radiotherapy. LH-RH agonists with or without antiandrogens can be also utilized prior to or following various local treatments in patients with clinically localized prostate cancer and at high risk for disease recurrence. LH-RH antagonists like Cetrorelix are in clinical trials. However, most patients with advanced prostatic carcinoma treated by any modality of androgen deprivation eventually relapse. Treatment of relapsed androgen-independent prostate cancer remains a major challenge, but new therapeutic modalities are being developed based on antagonists of growth hormone-releasing hormone (GH-RH) and bombesin, which inhibit growth factors or their receptors. Another approach consists of cytotoxic analogs of LH-RH, bombesin, and somatostatin containing doxorubicin or 2-pyrrolinodoxorubicin, which can be targeted to receptors for these peptides found in prostate cancers and their metastases. These cytotoxic analogs inhibit growth of experimental androgen-dependent or -independent prostate cancers and reduce the incidence of metastases. A rational therapy with peptide analogs could be selected on the basis of receptors present in biopsy samples. The approaches based on peptide analogs should result in a more effective treatment for prostate cancer.
 ...
PMID:Peptide analogs in the therapy of prostate cancer. 1102 15

Early clinical trials in Mexico with analogs of luteinizing hormone-releasing hormone (LH-RH) also known as gonadotropin releasing hormone (Gn-RH), were reviewed. Extensive clinical studies were carried out at IMSS with agonists of LH-RH, both in men and woman. All subjects responded to LH-RH agonists with a release of LH and FSH, but repeated administration of these analogs, initially aimed at stimulation of fertility (thought to stimulate fertility), was later shown to result in inhibition due to desensitization of pituitary gland and downregulation of LH-RH receptors. Various clinical investigations with LH-RH antagonists were also carried out. This included the first demonstration that LH-RHantagonists can suppress LH and FSH and sex steroid secretion in men and women. Various studies in Mexico with early LH-RH antagonists aimed at the development of new contraceptive methods were reviewed. Modern LH-RH antagonist Cetrorelix was shown to be effective in men and women and useful in treatment of uterine leiomyomas and benign prostatic hyperplasia. Major oncological studies were also carried out with agonist D-Trp6-LH-RH and antagonist Cetrorelix in men with prostate cancer, which demonstrated therapeutic efficacy of both types of analogs. Some endocrine studies with early analogs of somatostatin were also cited and a clinical trial with somatostatin analog vapreotide in patients with relapsed prostate cancer was reviewed. All these studies played a major role in introducing analogs of hypothalamic-releasing hormones into clinical medicine.
 ...
PMID:[History of clinical studies on hypothalamic hormone analogs in Mexico]. 1702 7

The discovery of hypothalamic hormones was briefly reviewed. The development of new hormonal methods for the therapy of various cancers based on analogues of hypothalmic hormones is then presented. My group isolated luteininzing hormone-releasing hormone (LH-RH), also known as Gn-RH, from pig hypothalmi, elucidated its amino acid sequence, and synthesized it in 1971. The interest in medical applications of LH-RH led to the synthesis of LH-RH analogues by various groups. LH-RH agonists substituted in positions 6 or 10 including Decapeptyl, Leuprolide and Zoladex are much more active than LH-RH and on continuous administration produce inhibition of pituitary and gonads. Chronic administration of LH-RH agonists is being utilized for the treatment of prostate and breast cancer. Octapeptide analogues of somatostatin have various applications in Oncology. In 1980 we developed a new endocrine therapy for advanced prostate cancer based on agonists of LH-RH, which is now preferred by 70-90% of prostate cancer patients for primary treatment. LH-RH antagonists such as Cetrorelix can be used for therapy of BPH. On the basis of the presence of specific receptors for hypothalamic peptides on human cancers, we developed targeted cytotoxic analogues of LH-RH, somatostatin, and bombesin/GRP linked to doxorubicin or 2-pyrrolinodoxorubicin. These analogues inhibit the growth of experimental human prostate, breast, ovarian and endometrial cancer, renal cell carcinoma, pancreatic, colorectal and gastric cancers, small cell lung carcinoma (SCLC) and non-SCLC, brain tumors, melanomas, and lymphomas. Cytotoxic LH-RH analogues are now in clinical trials. Recently we demonstrated that growth hormone-releasing hormone (GH-RH) also serves as an autocrine growth factor in many cancers. Antagonistic analogues of GH-RH synthesized in our laboratory inhibit the growth of diverse tumors. The discovery of LH-RH and somatostatin has led to clinical use of their analogues in the field of cancer treatment and GH-RH antagonists also show a great promise.
 ...
PMID:New approaches to the therapy of various tumors based on peptide analogues. 1849 Dec 50

Peptide analogues targeting various neuropeptide receptors have been used effectively in cancer therapy. A hallmark of adrenocortical tumor formation is the aberrant expression of peptide receptors relating to uncontrolled cell proliferation and hormone overproduction. Our microarray results have also demonstrated a differential expression of neuropeptide hormone receptors in tumor subtypes of human pheochromocytoma. In light of these findings, we performed a comprehensive analysis of relevant receptors in both human adrenomedullary and adrenocortical tumors and tested the antiproliferative effects of peptide analogues targeting these receptors. Specifically, we examined the receptor expression of somatostatin-type-2 receptor, growth hormone-releasing hormone (GHRH) receptor or GHRH receptor splice variant-1 (SV-1) and luteinizing hormone-releasing hormone (LHRH) receptor at the mRNA and protein levels in normal human adrenal tissues, adrenocortical and adrenomedullary tumors, and cell lines. Cytotoxic derivatives of somatostatin AN-238 and, to a lesser extent, AN-162, reduced cell numbers of uninduced and NGF-induced adrenomedullary pheochromocytoma cells and adrenocortical cancer cells. Both the splice variant of GHRH receptor SV-1 and the LHRH receptor were also expressed in adrenocortical cancer cell lines but not in the pheochromocytoma cell line. The GHRH receptor antagonist MZ-4-71 and LHRH antagonist Cetrorelix both significantly reduced cell growth in the adrenocortical cancer cell line. In conclusion, the expression of receptors for somatostatin, GHRH, and LHRH in the normal human adrenal and in adrenal tumors, combined with the growth-inhibitory effects of the antitumor peptide analogues, may make possible improved treatment approaches to adrenal tumors.
 ...
PMID:Expression of neuropeptide hormone receptors in human adrenal tumors and cell lines: antiproliferative effects of peptide analogues. 1971 19

Pheochromocytoma is a rare but potentially lethal chromaffin cell tumor with currently no effective treatment. Peptide hormone receptors are frequently overexpressed on endocrine tumor cells and can be specifically targeted by various anti-tumor peptide analogs. The present study carried out on mouse pheochromocytoma cells (MPCs) and a more aggressive mouse tumor tissue-derived (MTT) cell line revealed that these cells are characterized by pronounced expression of the somatostatin receptor 2 (sst2), growth hormone-releasing hormone (GHRH) receptor and the luteinizing hormone-releasing hormone (LHRH) receptor. We further demonstrated significant anti-tumor effects mediated by cytotoxic somatostatin analogs, AN-162 and AN-238, by LHRH antagonist, Cetrorelix, by the cytotoxic LHRH analog, AN-152, and by recently developed GHRH antagonist, MIA-602, on MPC and for AN-152 and MIA-602 on MTT cells. Studies of novel anti-tumor compounds on these mouse cell lines serve as an important basis for mouse models of metastatic pheochromocytoma, which we are currently establishing.
 ...
PMID:Anti-tumor effects of peptide analogs targeting neuropeptide hormone receptors on mouse pheochromocytoma cells. 2326 37