adrenomedullin and Endometrial-Neoplasms

Adrenomedullin (ADM) is a 52-amino acid peptide with structural homology to calcitonin gene-related peptide (CGRP) initially isolated from human pheochromocytoma. ADM is synthesized and is secreted from many mammalian tissues, including the adrenal medulla, endothelial and vascular smooth muscle cells, as well as the myocardium and central nervous system. ADM has been implicated as a mediator of several diseases such as cardiovascular and renal disorders, sepsis, inflammation, diabetes and cancer. ADM is also expressed in a variety of tumors, including breast, endometrial and prostate cancer. ADM has been shown to be a mitogenic factor capable of stimulating growth of several cancer cell types. In addition, ADM is a survival factor for certain cancer cells and an indirect suppressor of the immune response. ADM plays an important role in environments subjected to low oxygen tension, which is a typical feature of solid tumors. Under these conditions, ADM is up regulated and acts as a potent angiogenic factor promoting neovascularization. The major focus of this review will be on the role of ADM in cancer, with emphasis on its utility in diagnostic and prognostic terms, along with its relevance as a therapeutic target.

Topics: Adrenomedullin; Animals; Disease Progression; Endometrial Neoplasms; Female; Humans; Male; Neoplasms; Neovascularization, Physiologic; Ovarian Neoplasms; Pancreatic Neoplasms; Prognosis; Prostatic Neoplasms; Protein Biosynthesis; Receptors, Adrenomedullin; Receptors, Peptide; Signal Transduction

Adrenomedullin (AM) is a pluripotent peptide first discovered from human pheochromocytoma. AM expression has been shown in various cancer types including endometrium cancer. Bcl-2 is an antiapoptotic protein which might be regulated by AM in hypoxic conditions. The aim of the present study was to investigate the role of AM and Bcl-2 expressions in carcinogenesis of type-1 endometrium cancer.. Study group consisted of 10 proliferative endometrium, 22 simple endometrial hyperplasia, 23 endometrial intraepithelial neoplasia (EIN) and 30 Grade 1 endometrioid adenocarcinoma patients. AM and Bcl-2 expressions were investigated by immunohistochemistry.. Mean AM Allred score was 3±2.6, 5.6±1.6 and 5.7±2.5 in benign, EIN and adenocarcinoma groups, respectively. AM expression was significantly higher in EIN and adenocarcinoma groups than in benign endometrium group (p<0.05). Mean Bcl-2 Allred score was 6.4±2.1, 5.2±2.6, 2.3±2 in benign endometrium, EIN and adenocarcinoma groups, respectively. Mean Bcl-2 Allred score was similar between benign endometrium and EIN groups (p>0.05). However, it was significantly lower in adenocarcinoma group (p<0.05). An inverse correlation between AM and Bcl-2 expressions was found (r: -0.4, p<0.001).. Our findings showed that AM expression increased in progression from benign endometrium to EIN and type-1 adenocarcinoma while expression of Bcl-2 decreased in transition from EIN to carcinoma.

Topics: Adenocarcinoma; Adrenomedullin; Adult; Aged; Aged, 80 and over; Disease Progression; Endometrial Hyperplasia; Endometrial Neoplasms; Endometrium; Female; Humans; Immunohistochemistry; Middle Aged; Neoplasm Grading; Proto-Oncogene Proteins c-bcl-2

Endometrial cancer, in developed countries, is the most common malignancy of the female genital tract. Surgery and radiotherapy are successful in many patients but systemic and recurrent diseases have no consistently effective treatments, and for high grade advanced disease the prognosis is poor. The study investigated characteristics of adrenomedullin in endometrial cancer to assist in identifying targets for developing treatments.. Endometrial samples of women with and without cancer, and the Ishikawa cell line were used to investigate adrenomedullin mRNA regulation, peptide expression, adrenomedullin secretion and effects of adrenomedullin on VEGF secretion.. Expression of adrenomedullin mRNA was upregulated compared to that in healthy post-menopausal endometria. Adrenomedullin secretion was increased by cobalt chloride in this study. Secretion was reduced by the naturally-occurring compounds, (-)-epigallocatechin gallate (EGCG) and 3,4',5-trihydroxystilbene (resveratrol), which we have previously demonstrated to also suppress VEGF secretion in endometrial tumour tissue. We noted, for the first time, that adrenomedullin enhanced VEGF secretion from tumour cells.. Increased adrenomedullin expression may result in amplifying both tumorigenic and angiogenic activities. A substantial impact on growth of tumours may result in vivo as a consequence of the synergism between adrenomedullin and VEGF. Adrenomedullin, which has altered cellular characteristics in tumour compared to healthy tissue, offers an understudied target with potential to modify endometrial cancer behaviour, complementing other treatments.

Topics: Adenocarcinoma; Adrenomedullin; Biomarkers, Tumor; Case-Control Studies; Catechin; Cell Line, Tumor; Cobalt; Endometrial Neoplasms; Female; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Grading; Resveratrol; RNA, Messenger; Stilbenes; Up-Regulation; Vascular Endothelial Growth Factor A

Adrenomedullin (ADM) is a multifunctional 52-amino acid peptide involved in numerous physiological and pathological processes, including angiogenesis, growth regulation, differentiation, and vasodilation. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor, with specificity being conferred by receptor-associated modifying protein 2. The aim of the present study was to clarify the roles of ADM status, and tumor vessels in endometrium. Specimens were examined for ADM, microvessel density (MVD), area of venules (AV) and Bcl-2 oncoprotein using an immunoperoxidase method. The difference of ADM between normal proliferative phase and hyperplasia without atypia was significant (P < 0.05). The level of Bcl-2 was significantly different between hyperplasia without atypia and hyperplasia with atypia (P < 0.05). ADM, MVD and AV in the endometrium increased in a stepwise manner from normal, simple or complex hyperplasia with or without atypia to grade 1 adenocarcinoma. In contrast, expression of Bcl-2 oncoprotein was decreased. These parameters identify the role of ADM expression and Bcl-2 protein in relation to cell growth and vasodilating in the neoplastic changes.

Topics: Adenocarcinoma; Adrenomedullin; Adult; Endometrial Neoplasms; Endometrium; Female; Humans; Hyperplasia; Immunohistochemistry; Microvessels; Middle Aged; Neovascularization, Pathologic; Proto-Oncogene Proteins c-bcl-2

Estradiol (E(2)) rapidly and strongly induces vascular endothelial growth factor (VEGF) transcription in uterine endometrial epithelial cells in vivo. We have shown that this is mediated by both the estrogen receptor-alpha and hypoxia-inducible factor (HIF)-1alpha. By contrast, E(2) induces little or no VEGF expression in cultured breast or endometrial cancer cells, which lack HIF-1alpha due to the abnormally high concentration of oxygen ( approximately 20%) to which they are exposed. To test the hypothesis that restoring HIF-1alpha in cultured cells would restore the ability of E(2) to induce VEGF expression, we treated human endometrial cancer cells (ECC-1) with cobalt chloride (CoCl(2);100 microm), which prevents oxygen-induced HIF-1alpha degradation. HIF-1alpha was absent in untreated ECC-1 cells but detectable by 4 h after treatment with CoCl(2) alone, as was a significant increase in VEGF mRNA. E(2) plus CoCl(2) induced detectable HIF-1alpha expression at 2 h and an even higher level than that induced by CoCl(2) alone at 4 h; this HIF-1alpha was localized in the nuclei. This was accompanied by increasing VEGF expression, with the increase at 4 h severalfold higher than that induced by CoCl(2) alone and was concurrent with recruitment of both HIF-1alpha and estrogen receptor-alpha to the VEGF promoter. These results confirm that HIF-1alpha plays an essential role in E(2)-induced expression of VEGF. Through the induction of increased microvascular permeability and the consequent exudation of plasma growth factors, VEGF in turn may play an essential role in cancer cell proliferation in vivo.

Topics: Adrenomedullin; Blotting, Western; Cell Line, Tumor; Cell Nucleus; Cobalt; Cytoplasm; Endometrial Neoplasms; Estradiol; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Oxygen; Protein Transport; Reverse Transcriptase Polymerase Chain Reaction; Vascular Endothelial Growth Factor A

The angiogenic peptide adrenomedullin (ADM) has been implicated as a mediator of the increased risk of endometrial hyperplasia and cancer resulting from the use of tamoxifen for the treatment and prevention of breast cancer. ADM has been shown to be induced by tamoxifen in the endometrium and to be a growth factor for endometrial endothelial cells in vitro. We have now shown ADM to be strongly angiogenic in the mouse subcutaneous sponge angiogenesis assay. To examine the role of ADM in tumor growth, the ADM cDNA was transfected into endometrial carcinoma cells followed by xenografting into athymic mice. Two endometrial cancer cell lines were employed, those in which transfection and expression of ADM resulted in no effect on growthin vitro (Ishikawa cells) and those in which expressionof exogenous ADM stimulated in vitro growth (RL95.2 cells). A clear enhancement of tumor growth was seen with both cell lines but the effect was far greater with the RL95.2 cells. We conclude that ADM is pro-tumorigenic by stimulating either angiogenesis alone or by stimulating angiogenesis and carcinoma cell growth directly. The combined activities lead to a striking increase in tumor growth. These results provide the first direct evidence of tumorigenic activity of ADM and provide further support for ADMs involvement in tamoxifen induced endometrial neoplasia.

Topics: Adrenomedullin; Angiogenesis Inducing Agents; Animals; Calcitonin Gene-Related Peptide; Disease Models, Animal; Endometrial Neoplasms; Female; Humans; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Neovascularization, Pathologic; Peptide Fragments; Peptides; Transfection; Transplantation, Heterologous

Regions of hypoxia are a common feature of solid tumours. When tumour cells are exposed to hypoxic stress, transcription of a battery of genes is initiated. The angiogenic factor adrenomedullin (ADM) is a hypoxia regulated gene. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor (CRLR), with specificity being conferred by the receptor associated modifying protein 2 (RAMP2). Here we report for the first time that ADM treated or stably transfected Ishikawa cells overexpressing ADM show increased resistance to hypoxia induced apoptosis. These cells also show an upregulation of the oncoprotein Bcl-2, which is protective against hypoxic cell death when transiently transfected into Ishikawa cells. Since Ishikawa cells express the putative ADM-receptor CRLR-RAMP2 the production and secretion of ADM with the consecutive upregulation of Bcl-2 could establish an autocrine/paracrine mechanism rescuing malignant cells from hypoxic cell death. These results, taken together with our previous findings that ADM is an angiogenic factor which is upregulated by the nonsteroidal antiestrogen tamoxifen (TAM) in endometrial cells, implicate this peptide as a promoter of tumour growth and a possible target for anticancer strategies.

Topics: Adrenomedullin; Calcitonin Receptor-Like Protein; Cell Division; Cell Hypoxia; Cell Survival; Endometrial Neoplasms; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Peptides; Proto-Oncogene Proteins c-bcl-2; Receptor Activity-Modifying Protein 2; Receptor Activity-Modifying Proteins; Receptors, Calcitonin; Transfection; Tumor Cells, Cultured; Up-Regulation

We investigated tamoxifen's effects on the expression of growth regulatory genes in the endometrium to identify the mechanism by which tamoxifen induces proliferation.. Using immunohistochemical techniques, we analyzed 39 endometrial specimens for expression of Ki-67, lactoferrin, transforming growth factor-alpha, tumor necrosis factor receptor-II, adrenomedullin, estrogen receptors, and progesterone receptors. Twenty specimens were obtained from postmenopausal breast cancer patients treated with tamoxifen (20 mg/day) for at least 6 months to include two endometrial adenocarcinoma specimens. Five secretory phase, three proliferative phase, and seven atrophic endometrial specimens were used as controls. In addition, four endometrial adenocarcinoma specimens were reviewed from patients not treated with tamoxifen. Intensity of immunostaining was quantified using digitized imaging techniques.. Overexpression of both estrogen receptors and progesterone receptors, and an elevated proliferative index were the most consistent effects observed in benign endometrial specimens from tamoxifen-treated patients compared with atrophic controls (P <. 003). This staining pattern was also evident in adenocarcinomas from patients who received tamoxifen. Benign endometrium from tamoxifen-treated patients also expressed transforming growth factor-alpha, tumor necrosis factor receptor-II, lactoferrin, and adrenomedullin at levels comparable with those found in proliferative endometrial specimens.. These data provide further documentation that the uterotropic effects of tamoxifen may be due, at least in part, to the induction of estrogen receptors and progesterone receptors, as well as other genes associated with the proliferative phase. Furthermore, analysis of estrogen receptors, progesterone receptors, and Ki-67 may be useful in identifying postmenopausal individuals on tamoxifen, who are at increased risk for developing endometrial cancer.

Topics: Adrenomedullin; Antineoplastic Agents, Hormonal; Breast Neoplasms; Endometrial Neoplasms; Endometrium; Female; Gene Expression Regulation, Neoplastic; Genes, Regulator; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Lactoferrin; Peptides; Receptors, Estrogen; Receptors, Progesterone; Receptors, Tumor Necrosis Factor; Tamoxifen; Transforming Growth Factor alpha