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

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.

Water-Soluble Fullerene Derivatives as Brain Medicine: Surface Chemistry Determines If They Are Neuroprotective and Antitumor.

Delivering drugs to the central nervous system (CNS) is a major challenge in treating CNS-related diseases. Nanoparticles that can cross blood-brain barrier (BBB) are potential tools. In this study, water-soluble C60 fullerene derivatives with different types of linkages between the fullerene cage and the solubilizing addend were synthesized (compounds 1-3: C-C bonds, compounds 4-5: C-S bonds, compound 6: C-P bonds, and compounds 7-9: C-N bonds). Fullerene derivatives 1-6 were observed to induce neural stem cell (NSC) proliferation in vitro and rescue the function of injured CNS in zebrafish. Fullerene derivatives 7-9 were found to inhibit glioblastoma cell proliferation in vitro and reduce glioblastoma formation in zebrafish. These effects were correlated with the cell metabolic changes. Particularly, compound 3 bearing residues of phenylbutiryc acids significantly promoted NSC proliferation and neural repair without causing tumor growth. Meanwhile, compound 7 with phenylalanine appendages significantly inhibited glioblastoma growth without retarding the neural repair. We conclude that the surface functional group determines the properties as well as the interactions of C60 with NSCs and glioma cells, producing either a neuroprotective or antitumor effect for possible treatment of CNS-related diseases.