Undulating membraneous structures associated with the endoplasmic reticulum in tumour cells

Abstract

The morphology and occurrence of tubuloreticular and undulating membraneous structures (TRS and UMS) associated with the endoplasmic reticulum were examined under normal and pathologic conditions. It was concluded that TRS and UMS are cytoplasmic inclusions of similar type but of different organization. The occurrence of UMS in a human cell line derived from a carcinoma of the lung and in a transplantable chicken hepatoma derived from an MC-29 virus-induced liver tumour is described.

The Cubic “Faces” of Biomembranes

“…Not surprisingly, the ER was found to be the most prominent target of morphological alterations because of its highly convoluted structure and central functions in membrane lipid synthesis, assembly, secretion of membrane and secretory proteins, ion homeostasis, and membrane quality control. Thus, these morphologies (because of their complex morphology in TEM micrographs) appear under numerous nicknames in the literature, such as "undulating membranes" [29], "cotte de mailles" [30], "membrane lattice" [31], "crystalloid membranes" [32], "paracrystalline ER" [33], "tubuloreticular structures" [3,4,34], and "organized smooth ER" (OSER) that is formed in response to elevated levels of the membrane-resident protein cytochrome b(5) [21]. Quite remarkably, the most prominent examples of ER expansion are related ER stress condition and may occur, for example, as a response to hypoxia stress [35], drug treatment [36], or tumors [29], or specifically, upon stimulation of lymphocytes with lipopolysaccharide [37] or interferon [38].…”

Oxidation of Membrane Curvature-Regulating Phosphatidylethanolamine Lipid Results in Formation of Bilayer and Cubic Structures

“…12 They have been observed in smooth ER membranes of severe acute respiratory syndrome (SARS)-infected cells 13 and tumor cells in various organs. 10 One of the most well characterized in vivo cases of cubic phase formation results from the morphological transition of the inner MT membrane upon food depletion in the giant amoeba Chaos carolinensis . 12 The progressive formation of the cubic phase was accompanied by increasing levels of the reactive oxygen species (ROS) superoxide and hydrogen peroxide, resulting from changes in oxidative metabolism of the organism upon starvation.…”

“…36 Although chain packing does not permit the formation of cubic phases based on minimal surfaces at these large length-scales, it is interesting that DOPE oxidation apparently drives the generation of lipid structures with periodic symmetry, and does so at length-scales comparable to those of cubic structures observed in vivo . 10,12,37…”

Ultrastructure and Immunoelectron Microscopy of Human T-cell Leukaemia Virus Type I-producing Lymphoid and Non-lymphoid Human Tumour Cells

“…Although TRS appear in various types of virus-infected cell and tumour cell, they are not known to contain viral structural elements (Schaff et al, 1976). HTLV-I-producing T-lymphoid cells produce different types of lymphokine including 7-interferon (Salahuddin et al, 1984), and the appearance of TRS in these cells might be related to interferon induction rather than the virus production.…”