Angiogenesis Related Remodeling and Reprogramming in Melanomas

Introduction: Melanomas show a wide variation in pigmentation. The present study evaluates the role of angiogenesis in reprogramming/remodeling of the tumor through tumor vascular interactions. Methods: Paraffin and frozen sections from melanomas in vertical growth phase, were subjected to routine, enzyme/Immunohistochemistry, and electron microscopy. Quantitation was done by morphometric analysis of cell/nuclear size and density and mitotic counts to compare pigmented, amelanotic areas and tumor-vascular-complexes[TVCs]. Progression and fate of TVCs was assessed in 3D constructs of angiogenic vessels. Results: Pigmented areas show marked variation in cell/nuclear size, nuclear content and abnormal mitosis. Cells in amelanotic areas are uniform, with near normal morphometric values and synchronization of mitosis. Vasculogenesis is evident in amelanotic zones. Angiogenic tubes interact with tumor, forming 3D tumor-vascular-complexes [TVCs] with a central vessel and a perivascular mantle of cells, showing normal mitosis and regulated neural differentiation. Morphometric parameters and differentiation are graded proportionate to level of pigmentation. Discussion: TVCs grow into expansile nodules with peripheral pigmented layers which elicit further angiogenesis at the stromal margin. A cyclical process results in amelanotic nodules Angiogenesis from normal vasculature gives polarity and creates an embryonal microenvironment with reprogramming of pleomorphic pigmented to amelanotic near normal cells with embryonic characteristics. Clinically, the therapeutic strategies have to target both angiogenesis as well as the self propagating vascular networks. Corresponding author: Bhanu Iyengar. Pigment Cell Center, New Delhi, India. E-mail: [email protected] Received Date: April 18, 2015 Accepted Date: May 07, 2015 Published Date: May 13, 2015 Citation: Iyengar, B. Angiogenesis related Remodeling and Reprogramming in Melanomas. (2015) J Dermatol Skin Biol 1(1): 716. www.ommegaonline.com