Highly Selective Anti-Cancer Activity of Cholesterol-Interacting Agents Methyl-β-Cyclodextrin and Ostreolysin A/Pleurotolysin B Protein Complex on Urothelial Cancer Cells

Abstract

Cholesterol content can vary distinctly between normal and cancer cells, with elevated levels in cancer cells. Here, we investigated cholesterol sequestration with methyl-β-cyclodextrin (MCD), and pore-formation with the ostreolysin A/pleurotolysin B (OlyA/PlyB) protein complex that binds to cholesterol/sphingomyelin-rich membrane domains. We evaluated the effects on viability of T24 invasive and RT4 noninvasive human urothelial cancer cells and normal porcine urothelial (NPU) cells. Cholesterol content strongly correlated with cancerous transformation, as highest in the T24 high-grade invasive urothelial cancer cells, and lowest in NPU cells. MCD treatment induced prominent cell death of T24 cells, whereas OlyA/PlyB treatment resulted in greatly decreased viability of the RT4 low-grade noninvasive carcinoma cells. Biochemical and transmission electron microscopy analyses revealed that MCD and OlyA/PlyB induce necrotic cell death in these cancer cells, while viability of NPU cells was not significantly affected by either treatment. We conclude that MCD is more toxic for T24 high-grade invasive urothelial cancer cells, and OlyA/PlyB for RT4 low-grade noninvasive urothelial cancer cells, and neither is toxic for NPU cells. The cholesterol and cholesterol/sphingomyelin-rich membrane domains in urothelial cancer cells thus constitute a selective therapeutic target for elimination of urothelial cancer cells.

The barrier function of organotypic non-melanoma skin cancer models

“…We found decreased cholesterol and increased phospholipid levels as well as a shift in ceramide subclasses to higher levels of phytoceramides. Although cancer cell membranes contain increased cholesterol contents [33], reduced cholesterol amounts are found in patients' blood serum [34] and in particular in the medium surrounding tumor cells in vitro [35]. Keeping in mind that SC lipids are extruded to intercellular space from lamellar bodies [36], the SC does not represent the cancer cell membrane.…”

The role of lipid species in membranes and cancer-related changes

“…Cells that are resistant to the drug doxorubicin have been reported to have a higher degree of structural order in the PM [118] and to have higher levels of SM and CHOL [119] than the corresponding doxorubicin-sensitive cells. Urothelial cancer cells contained a CHOL level that correlated with the cancerous transformation, and it was proposed that the CHOL/SM-rich membrane domains in these cancer cells should constitute a selective therapeutic target for elimination of these cells [120]. Also, vinblastine-resistant human leukemic lymphoblasts were reported to have more CHOL (and ether phospholipids) than the corresponding vinblastinesensitive cells [121].…”

In vitro assessment of potential bladder papillary neoplasm treatment with functionalized polyethyleneimine coated magnetic nanoparticles

“…Interestingly, the overall cytotoxicity of NPs was greater in NPU cells than in RT4 cells, which is most probably due to a higher number of cell layers in RT4 cell model, but could also be due to the different molecular composition of cell membrane in RT4 and NPU cells. 39 Interestingly, the increasing NP concentration had only a small effect on cell viability. This can be explained by short exposure time, which limited the sedimentation and internalization of NPs.…”