Obesity alters the fitness of peritumoral adipose tissue, exacerbating tumor invasiveness in renal cancer through the induction of ADAM12 and CYP1B1.

Obesity exacerbates the risk and aggressiveness of many types of cancer. Adipose tissue (AT) represents a prevalent component of the tumor microenvironment (TME) and contributes to cancer development and progression. Reciprocal communication between cancer and adipose cells leads to the generation of cancer-associated adipocytes (CAAs), which in turn foster tumor invasiveness by producing paracrine metabolites, adipocytokines, and growth factors. Interfering with the crosstalk between CAAs and cancer cells is of key relevance in the prevention of tumor progression. The present study aimed to analyze the contribution of peritumoral AT in renal cell carcinoma (RCC) progression in lean versus overweight or obese patients. By isolating human adipose-derived stromal/stem cells from the three groups of patients and performing conditioned medium studies with RCC cells along with in vivo xenograft experiments, we found that peritumoral adipocytes from the three groups show a distinct expression profile of genes. In particular, ADAM metallopeptidase domain 12 (ADAM12) and cytochrome P450 family 1 subfamily B member 1 (CYP1B1) were found to be upregulated in obesity and their silencing reduced RCC cell invasiveness. In conclusion, high ADAM12 and CYP1B1 expressions in the peritumoral adipocytes boost tumor invasiveness and may serve as an indicator of poor prognosis in RCC.