Biological consequences of the physical organization of the plasma membranes of normal and tumor cells.
The differences in the physical organization of the membranes of normal and tumor cells are explained within the framework of the hypothesis of the presence of an intact framework on the surface of normal cells and the absence of it in tumor cells. An intact framework determines the possibility of existence of metastable states of the membrane and hysteresis phenomena in the lipid bilayer. The signals for transition to the S- and M-phases of the cycle are breakoffs of the metastable states, which occur only in the membranes of normal cells. The cell cycle in tumors is constructed only on physicochemical processes in the membrane without hysteresis phenomena, and the possibilities of regulating it are greatly weakened. This hypothesis permits: a) prediction of differences in the change in the microviscosity of the lipids of normal and tumor cells during their movement along the cycle and refinement of the concept of intactness of cells in the presence of a change in the microviscosity; b) elucidation of the role of the spreading of cells for the initiation of division in vitro; c) the proposal of a method of selective destruction of tumor cells with the aid of proteolytic and lipolytic enzymes; d) the proposal of an explanation for the weak antigenicity of many spontaneous tumors and the possibility of enhancing it. Experimental data on the properties of the membranes are discussed, and they are compared with the theoretical premises.
D000818:Animals; D000951:Antigens, Neoplasm; D002453:Cell Cycle; D002455:Cell Division; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure*; D006801:Humans; D037102:Lectins / Q000494:pharmacology; D008051:Lipid Bilayers; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology; D008954:Models, Biological; D008961:Models, Structural; D009369:Neoplasms / Q000503:physiopathology / Q000648:ultrastructure*
D000951:Antigens, Neoplasm; D037102:Lectins; D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins