Tissue-specific changes in expression of Vegfr2 in tumor and normal tissues of lymphoma-bearing BALB/c mice under chronic restraint stress.

Objective: Alteration of the expression of vascular endothelial growth factor (VEGF) and its receptors, VEGFR-1 and VEGFR-2, leads to aberrant angiogenesis in cancer; this is exacerbated by chronic stress. Our main aim was to determine the effect of chronic restraint stress on the expression of Vegfr2, the gene encoding VEGFR-2, in tumor, fat, skeletal muscle and brain in a murine model of lymphoma.

Results: We found that both chronic stress and tumor burden alter Vegfr2 expression. Under chronic stress, Vegfr2 is differentially expressed in inguinal adipose tissue, decreasing in tumor-free, and increasing in tumor-bearing animals. In skeletal muscle, brain, and tumor, Vegfr2 expression was upregulated by chronic stress. Adipose tissue, brain and skeletal muscle of tumor-bearing animals also showed changes in Vegfr2 expression during tumor progression. We also found that for skeletal muscle the combination of chronic stress and tumor burden enhances Vegfr2 expression (23-folds).

Conclusion: Chronic stress and tumor burden influence Vegfr2 expression in normal and tumoral tissues and their co-occurrence enhances its effect on skeletal muscle.