The Expression Of IGF-IR In Different Stages Of Human Dermal Hemangiomas

Hemangiomas are benign tumors of the vascular endothelium and are the most common tumors of infancy. These tumors are characterized by an initial phase of rapid proliferation, which is followed, in most cases, by spontaneous involution. Although most lesions resolve without complication, there are some cases in which hemangiomas can be life threatening when occurring near a vital structure. Hemangiomas, particularly facial lesions, can be disfiguring and also often carry a significant psychosocial component for the patient and family. Treatment for these aggressive tumors represents an unmet clinical need. In addition, this characteristic progression of hemangiomas through distinct phases provides a unique opportunity for studying endothelial cell biology and angiogenesis.Therapy includes corticosteroid, interferon, vincristine, and, sometimes, surgical resection. However, these pharmacological treatments are not without side effects and complications .Targeted therapy will require a better understanding of the cellular and molecular basis underlying the pathogenesis of this tumor.There was also evidence that IGF-II may have roles in angiogenesis and hemangiomas. IGF-II is a reasonable putative regulator of hemangioma proliferation, because it is a known mitogen and suppresses apoptosis. The function of this protein has been characterized, as has its primary functional receptor, IGF-IR. Although its expression profile was not as dramatic, IGF-I cannot be ruled out as a potential stimulator of hemangioma growth, and it is possible in fact, that IGF-I and IGF-II have cooperative effects because they share IGF-IR as a major receptor.The existence of the type I insulin-like growth factor receptor (IGF-IR) had been surmised for a number of years, before it was cloned in 1986 by Ullrich et al. At that time, the IGF-IR was considered a poor relative of the insulin receptor (IR), with which it has a 70% homology, a sort of redundant receptor that the cells used when the IR was defective. The past years have established the IGF-IR as an independent receptor, with overlapping, but different, functions from the IR and playing important roles in apoptosis, cancer, differentiation and even longevity. Many commentary focus on the role of the IGF-IR in cancer, with special emphasis on its use as a possible target for therapeutic purposes.In the present study, we study the relationship between IGF-IR and the progress of hemangioma. The expression of IGF-IR in the difference stages (proliferative stage and involuting stage) of hemangiomas was measured using SP immunohistochemical method and RT-PCR, comparing with vascular malformation and normal skin tissues at same time. The results of both SP immunohistochemical method and RT-PCR showed that the expression of IGF-IR in the proliferative stage of hemangioma was much higher than that in vascular malformation and normal skin tissues. The expression of IGF-IR in the insolving stage of hemangioma was decreased to a similar level to vascular malformation and normal skin tissues. There is significantly positive correlation between the expression of IGF-IR and proliferative degree of hemangioma, IGF-IR can provide information for the differential diagnosis of hemangioma which may provide a new train of though for finding the target to diagnose and treat hemangioma.