Molecular pathology of lung cancer and insulin-like growth factors

Molecular pathology of lung cancer (LC) investigates molecular-genetic rearrangements initiating development and growth of the tumor. The system of insulin-like growth factors (IGF) and binding proteins (IGFBP) regulates cell proliferation in the majority of embryonal and tumor tissues of man and animals in the course of reparation processes and productive inflammatory reaction. A general property of all LC histological types is presence in their cells of various members of IGF-system. Content of IGFII in tumor cells correlated with IGFBP-1, IGFBP-2, IGFBP-5. Location of IGFII and IGFBP in LC was different. IGFBP-1, -2, and -5, blocking IGFII, are detected in large amounts in areas of cell death inducing apoptosis while IGFII accumulates in dividing cells and foci of keratinization. Nuclear deposits of IGFBP-3 in bronchioloalveolar LC create phenomenon of intranuclear inclusion of "owl's eye" type. Synthesis of the majority of IGF occurs in tumor cells. Stromal cells also produce and transport into the tumor some quantity of IGFII and IGFBP.