The Continuing Evolution of Insulin-like Growth Factor Signaling.

Area of Science:

• Endocrinology
• Oncology
• Neuroscience

Background:

• Insulin-like growth factors (IGFs) are conserved ligands crucial for cell and organismal growth.
• IGF actions are mediated by receptor tyrosine kinases (IGF1 receptor, insulin receptor) and binding proteins.
• IGF signaling plays a significant role in both cancer biology and central nervous system (CNS) function.

Purpose of the Study:

• To review recent findings on the role of IGF signaling in cancer.
• To examine the involvement of IGF signaling in CNS function, including neurodegenerative diseases.
• To discuss the ongoing controversies regarding IGF signaling inhibition in cancer and its impact on longevity and CNS health.

Main Methods:

• Literature review of recent findings on IGF signaling.
• Analysis of studies investigating IGF1 receptor overexpression in tumorigenesis, resistance, and metastasis.
• Examination of evidence linking insulin resistance in the CNS to cognitive impairment and dementias.

Main Results:

• Overexpression of IGF1 receptors is linked to enhanced tumorigenesis, acquired resistance, and metastasis in various cancers.
• Insulin resistance in the CNS, independent of systemic resistance, is characterized by reduced insulin and IGF1 receptor signaling.
• Reduced IGF signaling in the CNS may contribute to dementias such as Alzheimer's Disease and cognitive impairment.

Conclusions:

• IGF signaling is a complex factor in cancer biology, with ongoing debate about the benefits of its inhibition.
• IGF signaling dysfunction in the CNS is associated with cognitive decline and neurodegenerative diseases.
• Further research is needed to clarify the multifaceted roles of IGF signaling in health and disease, including longevity.