Peroxisome proliferator-activated receptor γ (PPARγ) and colorectal carcinogenesis

Peroxisome proliferator-activated receptor γ (PPARγ) a member of the nuclear transcription factor superfamily is playing a role in colon carcinogenesis. Although not all in vivo models agree, PPARγ seems to have suppressive effects in this process favoring apoptosis and inhibiting the cell cycle by inducing expression of apoptosis and senescence proteins. With the recent discovery that anti-diabetic class of drugs thiazolidinediones act through activation of PPARγ, interest in this transcription factor has increased as it can now be pharmacologically activated in order to obtain tumor suppression. In addition, thiazolidinediones and other PPARγ agonists possess PPARγ-independent anti-tumor effects. Although PPARγ agonists may not by themselves be capable to induce clinical tumor regression, their combination with chemotherapy drugs or other targeted therapies is worth pursuing in the treatment of colorectal carcinoma.