Endocrine Abstracts

Background: The growth hormone/ IGF-I axis is important in the pathogenesis of breast cancer and increased IGF-I signalling through the IGF-I receptor (IGF-IR) has been implicated in the development of tamoxifen resistance in breast cancer.Aims: To compare mRNA and protein expression of IGF-I & IGF-IR in (i) wild type (WT) and tamoxifen resistant (TR) MCF-7 breast cancer cells and (ii) breast cancer tissue from women with primary and recurrent, tamox...

Background: Due to its cross-talk with estrogen receptor (ER) signalling, increased IGF-I signalling through the IGF-I receptor (IGF-IR) has been postulated as an important factor in the development of tamoxifen resistance in breast cancer.Aims: To investigate the importance of IGF-I signalling in tamoxifen resistant (TR) and wild-type (WT) MCF-7 breast cancer cells by (i) assessing cell proliferation in response to IGF-I and tamoxifen and (ii) using sma...

Introduction: The development of colorectal cancer is influenced by dietary as well as growth factors. Butyrate, (NaB) one of the metabolic by-products of bacterial fermentation of dietary fibre is a primary source of energy for colonic mucosa. It has growth-promoting effects on normal colonic epithelial cells, induces cell cycle arrest, differentiation and apoptosis in colorectal cancer cells. Since it has been suggested that the apoptotic effects of NaB may be due to its syn...

Cannabinoids and ghrelin are potent appetite stimulators. The ghrelin receptor (GHS-R1a), endocannabinoids and the cannabinoid 1 (CB1) receptor are expressed in the hypothalamus. There is evidence that the novel CB1 antagonist, rimonabant, causes weight loss by both central and peripheral effects. The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status and regulates the energy metabolism within the single cell but also at whole body level. We have shown p...

Introduction:Hepatic IGF-I is generally believed to be regulated by pituitary-derived GH. However recent studies have emphasized the importance of paracrine/autocrine IGF-I in normal growth and development, as well as some malignancies. However, it remains unclear how locally produced IGF-I is regulated. The aim of this project was to investigate IGF-I expression in different tissues from the growth hormone receptor knock-out (GHR-KO) mouse.<p class=...

Introduction: The GH/IGF-I axis has been implicated in the pathogenesis of breast cancer and development of tamoxifen resistance. We have previously used siRNA to successfully silence the IGF-I receptor (IGF-IR) in MCF-7 breast cancer cells. To further characterize the growth changes that occur when elements of the GH/IGF-I axis are disrupted we investigated the use of siRNA to cause long term silencing of IGF-IR.Methods: MCF-7 cells were cultured in phe...

Background: Previous studies have implicated the GH/IGF-I axis in the pathogenesis of breast cancer and the development of tamoxifen resistance. IGF-I is a known proliferative and anti-apoptotic agent. In order to characterize the growth changes that occur when elements of the GH/IGF-I axis are disrupted we have used siRNA to transcriptionally silence the IGF-IR in the MCF-7 human breast cancer cell line.Methods: MCF-7 cells were cultured in phenol red-f...

IntroductionIncreased cross talk between the IGF-I and oestrogen signalling pathways has been implicated in the development of tamoxifen resistance in breast cancers. We have previously demonstrated IGF-I mRNA to be down-regulated in primary breast cancers. However, the expression of IGF-I and IGFBP-3 in recurrent, tamoxifen-resistant tumours is unknown.MethodsTotal RNA was extracted from 38 paired samples of...

IntroductionIncreased cross talk between the IGF-I and oestrogen signalling pathways has been implicated in the development of tamoxifen resistance in breast cancers. We have previously demonstrated IGF-I mRNA to be down-regulated in primary breast cancers. However, the expression of IGF-I and IGFBP-3 in recurrent, tamoxifen-resistant tumours is unknown.MethodsTotal RNA was extracted from 38 paired samples of primary breast cancers (T) and adjacent normal (N) tissue and from 1...

BackgroundIn addition to inhibiting pituitary GH secretion, somatostatin (SS) and its analogues have been shown to exert anti-proliferative effects on a variety of different cell types. The presence of receptors for SS have been demonstrated in a number of tissues but quantification of mRNA expression of the 5 subtypes of SSTR in the colon is unknown.MethodsTotal RNA was extracted from 9 paired samples of adj...