Endocrine Abstracts

Background: The pro-proliferative and anti-apoptotic IGF-I is implicated in the development of colorectal cancer (CRC) in both the general population and patients with acromegaly. The local intracolonic environment is also likely to be important, particularly unconjugated bile acids such as deoxycholic acid (DCA). Whilst low faecal concentrations may be proliferative, high levels are toxic to colonic epithelial cells.High levels of DCA have been linked t...

Background: The growth hormone/ insulin-like growth factor-1 (GH/IGF-1) axis has been increasingly implicated in the pathogenesis of breast cancer. We have recently demonstrated the local expression of both GH and IGF-I in normal and malignant breast tissue. However, the regulation of this local GH/IGF-1 expression is unknown. Aims: (i) To quantify the mRNA levels of GHRH, ghrelin and their receptors in malignant and adjacent normal breast tissue, and (ii) to determine any cor...

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 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...

Background:The growth hormone/insulin-like growth factor-I (GH/IGF-I) axis has been increasingly implicated in the development of breast cancer. Previously we have demonstrated the local expression of IGF-I in normal and malignant breast tissue. However the correlation of this local expression with clinical factors has not fully been investigated.Aims: (i) To quantify the mRNA levels of IGF-I in normal and malignant breast tissue and (ii) to identify any correlation betwee...

Background:Recent studies have linked low serum levels of IGFBP-3 with an increased risk of developing breast cancer.In addition to modulating IGF-I bioactivity, IGFBP-3 also exerts IGF-I independent pro-apoptotic effects. Our previous work has demonstrated that IGFBP-3 mRNA expression is significantly down regulated in breast tumours compared to normal breast tissue. It is uncertain, however, how this pattern of expression relates to the pathological and prognostic features o...