Insulin-like growth factor 2 in development and disease: a mini-review.

BACKGROUND Insulin-like growth factor 2 (IGF2) is a protein hormone known to regulate cell proliferation, growth, migration, differentiation and survival. The gene is parentally imprinted in the sense that transcripts are almost exclusively derived from the paternal allele. Loss of imprinting of the IGF2 gene is a recurrent observation in growth disorders that combine overgrowth with a variety of malignant tumours. Moreover, IGF2 has been proposed to play a role in the development of a variety of seemingly unrelated cancers that play an important role in geriatric medicine, e.g., breast cancer, colon cancer and lung cancer. Finally, IGF2 has been implicated in cardiovascular disease, since, for example, IGF2 has been shown to influence the size of atherosclerotic lesions. OBJECTIVE To summarize current knowledge about IGF2, its interactions with binding proteins and receptors and connections with key diseases. METHODS The contents of this paper were based on reviews of existing literature within the field. RESULTS There is a substantial amount of research linking IGF2 to growth disorders, cancer and to a much lesser degree cardiovascular disease. Some of the studies on IGF2 and tumour growth have yielded conflicting results, for instance regarding its effect on apoptosis. CONCLUSION Today, our knowledge on how IGF2 is composed and interacts with receptors has come a long way. However, there is comparatively little information on how IGF2 affects tumour growth and cardiovascular diseases such as atherosclerosis. Thus, further research will be needed to elucidate the impact of IGF2 on key diseases.