The BET inhibitor JQ1 selectively impairs tumour response to hypoxia and downregulates CA9 and angiogenesis in triple negative breast cancer

The availability of bromodomain and extra-terminal inhibitors (BETi) has enabled translational epigenetic studies in cancer. BET proteins regulate transcription by selectively recognizing acetylated lysine residues on chromatin. BETi compete with this process leading to both downregulation and upregulation of gene expression. Hypoxia enables progression of triple negative breast cancer (TNBC), the most aggressive form of breast cancer, partly by driving metabolic adaptation, angiogenesis and metastasis through upregulation of hypoxia-regulated genes (for example, carbonic anhydrase 9 (CA9) and vascular endothelial growth factor A (VEGF-A). Responses to hypoxia can be mediated epigenetically, thus we investigated whether BETi JQ1 could impair the TNBC response induced by hypoxia and exert anti-tumour effects. JQ1 significantly modulated 44% of hypoxia-induced genes, of which two-thirds were downregulated including CA9 and VEGF-A. JQ1 prevented HIF binding to the hypoxia response element in CA9 promoter, but did not alter HIF expression or activity, suggesting some HIF targets are BET-dependent. JQ1 reduced TNBC growth in vitro and in vivo and inhibited xenograft vascularization. These findings identify that BETi dually targets angiogenesis and the hypoxic response, an effective combination at reducing tumour growth in preclinical studies.

Abstract P2-02-03: The Collagen Receptor Endo180: A Metastatic Plasma Marker In Breast Cancer Modulated By Bisphosphonate Treatment

Purpose: To establish whether the collagen remodelling receptor, Endo180, should be given consideration as a useful plasma marker in metastatic breast cancer.

Patients and Methods: Analysis of MCF-7 and MDA-MB-231 cell conditioned medium validated the anti-human (39.10) monoclonal antibody as suitable for the detection of soluble Endo180 in plasma. Eighty-seven breast cancer patients with early primary, locally advanced and metastatic disease were included in the study. Correlations between Endo180, CA 15–3 antigen (MUC1; mucin 1) and bisphosphonate treatment were investigated.

Results: Endo180 was elevated in metastatic compared to early breast cancer (P <.0001) and was able to differentiate locoregional disease and visceral and/or osseous metastasis (P = .0005). In combination CA 15–3 antigen (cut-off: 28 U/mL) and Endo180 (relative plasma level cut-off range: 0.95–1.65) had sensitivity of 94–97% and specificity of 52–68%. Endo180 levels were significantly higher in patients who were treatment naive (2.17 ± 0.82, N = 13) compared to those previously (1.82 ± 0.33, N = 5) or currently (1.37 ± 0.74, N = 24) receiving bisphosphonates (P = .011). In the bisphosphonate naive setting (N = 57) the combination of Endo180 (relative plasma level cut-off range: 0.95–1.65) and CA 15–3 antigen (cut-off: 28 U/mL) had a sensitivity of 87–92% and specificity of 72–79%.

Conclusion: Endo180 is a plasma marker with high sensitivity in metastatic breast cancer that can be modulated by bisphosphonate treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-02-03.

Can healthy lifestyle modify risk factors for dementia? findings from a pilot population-based survey

Introduction

Aspects of lifestyle are a key component to successful ageing and reducing the risk of cognitive impairment. Many developing countries, including India, currently have a much lower rate of dementia in people of the same age in the UK (Alzheimer’s Disease International 2008), in contrast to the higher prevalence rates of cardiovascular risk factors (reviewed in Misra and Kurana, 2009).

Objectives

Compare lifestyle choices in a developed and a developing country, that show contrasting dementia prevalence rates.

Aims

Identify protective factors that may reduce dementia prevalence.

Methods

A total of 251 participants at public meetings (123 in Newcastle and 128 in Chennai) on ageing completed a questionnaire voluntarily regarding their lifestyle, health status, 4-item GDS, and their subjective perception of their mental and physical health. The two groups had similar sociodemographic characteristics.

Results

Diabetes was three times more prevalent in the Chennai group (p = 0.001) but a significantly higher proportion of the Chennai population reported receiving treatment for diabetes (p = 0.012). Vegeterian diet was more frequent in the Chennai cohort (p = 0.000), as well as curry consumption (p = 0.000). The Newcastle group consumed more alcohol (p = 0.000) and practiced exercise less often (p = 0.005). Not surprinsingly, 95% of the Indian is religious, in contrast to 59.7% of the English (p = 0.000).

Conclusions

Type of diet, curry and alcohol consumption, and religious or spiritual beliefs, were the most significantly different, and may therefore confer protective advantages for dementia. Other explanations could be a higher proportion of uncontrolled diabetes and inactive people in the Newcastle sample.