Alcohol promotes breast cancer cell invasion by regulating the Nm23-ITGA5 pathway

<p>Abstract</p> <p>Background</p> <p>Alcohol consumption is an established risk factor for breast cancer metastasis. Yet, the mechanism by which alcohol promotes breast cancer metastases is unknown. The ability of cancer cells to invade through tissue barriers (such as basement membrane and interstitial stroma) is an essential step towards establishing cancer metastasis. In the present study, we identify and examine the roles of two genes, <it>Nm23 </it>and <it>ITGA5</it>, in alcohol-induced breast cancer cell invasion.</p> <p>Methods</p> <p>Human breast cancer T47D cells were treated with ethanol at various concentrations. Boyden chamber invasion assays were used to measure cellular invasive ability. The mRNA expression level of metastasis suppressor genes including <it>Nm23 </it>was determined by qRT-PCR. <it>ITGA5 </it>was identified using a qRT-PCR array of 84 genes important for cell-cell and cell-extracellular matrix interactions. <it>Nm23 </it>overexpression in addition to <it>Nm23</it>- and <it>ITGA5 </it>knock-down were used to determine the role of the Nm23-ITGA5 pathway on cellular invasive ability of T47D cells. Protein expression levels were verified by Western blot.</p> <p>Results</p> <p>Alcohol increased the invasive ability of human breast cancer T47D cells in a dose-dependent manner through the suppression of the <it>Nm23 </it>metastatic suppressor gene. In turn, <it>Nm23 </it>down-regulation increased expression of fibronectin receptor subunit <it>ITGA5</it>, which subsequently led to increased cellular invasion. Moreover, <it>Nm23 </it>overexpression was effective in suppressing the effects of alcohol on cell invasion. In addition, we show that the effects of alcohol on invasion were also inhibited by knock-down of <it>ITGA5</it>.</p> <p>Conclusions</p> <p>Our results suggest that the Nm23-ITGA5 pathway plays a critical role in alcohol-induced breast cancer cell invasion. Thus, regulation of this pathway may potentially be used to prevent the establishment of alcohol-promoted metastases in human breast cancers.</p

Effects of body weight and alcohol consumption on insulin sensitivity

<p>Abstract</p> <p>Background</p> <p>Obesity is a risk factor for the development of insulin resistance, which can eventually lead to type-2 diabetes. Alcohol consumption is a protective factor against insulin resistance, and thus protects against the development of type-2 diabetes. The mechanism by which alcohol protects against the development of type-2 diabetes is not well known. To determine the mechanism by which alcohol improves insulin sensitivity, we fed water or alcohol to lean, control, and obese mice. The aim of this study was to determine whether alcohol consumption and body weights affect overlapping metabolic pathways and to identify specific target genes that are regulated in these pathways.</p> <p>Method</p> <p>Adipose tissue dysfunction has been associated with the development of type-2 diabetes. We assessed possible gene expression alterations in epididymal white adipose tissue (WAT). We obtained WAT from mice fed a calorie restricted (CR), low fat (LF Control) or high fat (HF) diets and either water or 20% ethanol in the drinking water. We screened the expression of genes related to the regulation of energy homeostasis and insulin regulation using a gene array composed of 384 genes.</p> <p>Results</p> <p>Obesity induced insulin resistance and calorie restriction and alcohol improved insulin sensitivity. The insulin resistance in obese mice was associated with the increased expression of inflammatory markers Cd68, Il-6 and Il-1α; in contrast, most of these genes were down-regulated in CR mice. Anti-inflammatory factors such as Il-10 and adrenergic beta receptor kinase 1 (Adrbk1) were decreased in obese mice and increased by CR and alcohol. Also, we report a direct correlation between body weight and the expression of the following genes: Kcnj11 (potassium inwardly-rectifying channel, subfamily J, member 11), Lpin2 (lipin2), and Dusp9 (dual-specificity MAP kinase phosphatase 9).</p> <p>Conclusion</p> <p>We show that alcohol consumption increased insulin sensitivity. Additionally, alterations in insulin sensitivity related with obesity were coupled with alterations in inflammatory genes. We provide evidence that alcohol may improve insulin sensitivity by up-regulating anti-inflammatory genes. Moreover, we have indentified potential gene targets in energy metabolic pathways and signal transducers that may contribute to obesity-related insulin resistance as well as calorie restriction and alcohol-induced insulin sensitivity.</p