Abstract
Obesity has been associated with increased incidence and mortality of breast cancer. The precise relation between obesity and breast cancer is yet to be determined, with few studies linking them with altered serum levels adipokines and inflammatory cytokines. The relevance of the expression of genes encoding for adipokines and inflammatory cytokines in the peripheral blood and their contribution to obesity and breast cancer has not been fully investigated. We aim to identify potential transcriptional biomarkers in blood samples that may assist to underpin the link between obesity and breast cancer. Therefore, have investigated whether or not the expression levels, of selected genes [tumor necrosis factor-alpha (TNF alpha), interleukin 6 (IL-6), adiponectin, leptin, C-reactive protein (CRP), parathyroid hormone (PTH), tumor protein 53 (TP53) and erythroblastic leukemia viral oncogene 2 (ErbB2)] were altered in blood samples of lean, overweight/obese and breast cancer subjects. Blood samples were obtained from 37 lean, 19 overweight/obese and 12 breast cancer patients. Real-time polymerase chain reaction assays were performed to detect TNF alpha, IL-6, adiponectin, leptin, CRP, PTH, TP53 and ErbB2 gene transcripts. Transcript levels of TNFa were significantly higher by 1.4-fold and 2.1-fold in blood cells of overweight/obese and breast cancer patients, respectively, compared with lean control subjects. Transcript levels of IL-6 were significantly higher by 2.3-fold in blood cells from breast cancer patients compared with lean control subjects with normal body mass index, and no significant difference was found in the expression level of IL-6 transcripts between overweight/obese and lean control subjects. The ErbB2 transcript levels were significantly higher by 4.72-fold compared to lean control subjects and were also significantly higher compared to overweight/obese subjects. Breast cancer and obesity are associated with altered mRNA levels of cytokines and tumor marker in peripheral blood.