Obesity is associated with genetic changes in adipose tissue surrounding the prostate that generates an ideal environment for prostate cancer growth and progression, scientists claim. A team headed by investigators at the Clínica Universidad de Navarra (Spain) and the Portuguese Institute of Oncology compared gene expression in adipose tissue surrounding the prostate (periprostatic, or PP, adipose tissue) in lean and obese/overweight (OB/OW) men with benign prostatic hyperplasia, or prostate cancer that was either confined to the prostate or had escaped into the surrounding PP adipose tissue.
The results showed that the PP adipose tissue of OB/OW men exhibited altered expression of genes involved in adipogenic/anti-lipolytic, proliferative/anti-apoptotic, and mild immunoinflammatory processes. Of particular note was the upregulation of the anti-apoptotic genes ANGPT1 and HSPB8, and increased expression of genes involved in cell growth and differentiation, such as LEP and again ANGPT1. The products of these two genes increase endothelial, mesenchymal, and tumor cell growth and differentiation. Also upregulated was NPY1R, which mediates a proliferative stimulus in progenitor adipose cells.
The overall effects of altered gene expression were likely to include fat mass expansion “conferring increased capacity for enlarged adipocytes to express adipokines and increase fatty acid supplies, which might impact the local energy and availability of growth factors, thereby causing the local environment to allow cancer progression,” Gema Frühbeck, M.D., and colleageus write in their published paper in BMC Medicine.
“We showed that the PP adipose tissue gene expression profile of OB/OW subjects may contribute to increased local adiposity, a mild immunoinflammatory environment and production of molecules with oncogenic potential...This environment in the PP adipose tissue of OB/OW men may, at least partially, explain the described association of obesity and excess adiposity with the progression of prostate cancer.”
The authors report their results in a paper titled “Obesity and prostate cancer: gene expression signature of human periprostatic adipose tissue.”