Signal Transducer and Activator of Transcription 3 in Obesity-induced Cancers

[ABSTRACT] According to accumulating epidemiological studies, obesity triggers various diseases, including cancer. Because cancer is a leading cause of death, revealing relationships between obesity and cancer is an urgent task. However, the exact mechanisms of cancer progression in an obese state are not fully understood. Signal transducer and activator of transcription 3 (STAT3) likely plays an important role in this mechanism. A variety of upstream molecules activate and regulate STAT3 and include obesity-related molecules, such as adipokines. STAT3 alters multiple cellular functions in cancer. In fact, STAT3 activation leads to inflammation, cell proliferation, invasion, stem cell-like properties, and drug resistance. STAT3 is increasingly reported to function as a bridge between obesity and cancer. Furthermore, recent studies indicate that STAT3 activation leads to obesity-related carcinogenesis.