Characteristic of Ultrastructure of Mice B16 Melanoma Cells under the Influence of Different Lighting Regimes

Abstract

Circadian rhythms of physiological processes, constantly being in a state of dynamic equilibrium and plastically associated with changes in environmental conditions, are the basis of homeostasis of an organism of human and other mammals. Violation of circadian rhythms due to significant disturbances in parameters of main environmental effectors (desynchronosis) leads to the development of pathological conditions and a more severe course of preexisting pathologies. We conducted the study of the ultrastructure of cells of mice transplantable malignant melanoma B16 under the condition of normal (fixed) lighting regime and under the influence of constant lighting. Results of the study show that melanoma B16 under fixed light regime represents a characteristic picture of this tumor—predominantly intact tissue with safe junctions of large, functionally active cells with highly irregular nuclei, developed organelles and a relatively low content of melanin. The picture of the B16 melanoma tissue structure and the ultrastructure of its cells under the action of constant lighting stand in marked contrast to the group with fixed light: under these conditions the tumor exhibits accelerated growth, a significant number of cells in the state of apoptosis and necrosis, ultrastructural signs of degradation of the structure and functions, and signs of embryonization of cells with the background of adaptation to oxygen deficiency.

Human and animal cells under influence of different lighting and stimulus

“…Thus, scientific findings have already demonstrated that B16 under low dosage of light regime preserve characteristic of this tumor like intact tissue safe junctions, functionally active cells with highly irregular nuclei, developed organelles and a relatively low content of melanin. But in contrast the B16 melanoma tissue structure and the ultrastructure under the action of high constant lighting exhibits accelerated growth, increased melanin levels, as significant number of cells in the state of apoptosis and necrosis, like signs of embryonization with background of adaptation to oxygen deficiency [69]. For example, the mice genes, tyrosinase (tyr) [28,70] , solute carrier family 45 member 2 (SLC45A2) [28,71] solute carrier family 24 member 5 (SLC24A5) [28,72] melanopsin, (OPN4) and , rhodopsin, (OPN2) have been identified withal important role in the production of melanin in B16-F10 and Melan-a cells (Table 2) [27,28,73].…”