title: Tri-dimensional prostate cell cultures in simulated microgravity and induced changes in lipid second messengers and signal transduction.
abstract: The high aspect rotating-wall vessel (HARV) was designed to cultivate cells in an environment that simulate microgravity. We studied previously the effects of HARV cultivation on DU-145 human prostate carcinoma cells. We determined that HARV cultivation produced a less aggressive, slower growing, less proliferative, more differentiated and less pliant cell than other cell cultivation methods. The result was a 3-dimensional (3D) growth model of prostate cancer which mimics in vivo tissue growth. This work examines the signal transduction-second messenger pathways existing temporarily in these HARV cells and correlates these features with the special properties in growth and 3D spheroid formation. We found an initial very active ceramide, a diacylglycerol increase together with increases in PI-PLC and PLA(2) a central defect in PLD (no phosphatic acid or phosphatidylethanol at any time during 15 days of HARV cultivation). There is a cross-talk between ceramide and PI3K pathways with activation of PI3K, after 6 days of HARV growth concomitant with down-regulation of ceramide. At this time, there is also an increase of cAMP (seen by increases in arachidonic acid). Taken together these results can explain the 3D organoid-like growth. We therefore developed a model for growth in HARV prostate cancer cells which involve temporal "switches" between second messengers, activation and cross-talk between multiplicity of signaling pathways and a central defect in PLD pathways. Essential to the late slow growth, and 3D organotypic formation are the apoptotic, anti-survival, anti-proliferation and differentiation pathways in the first days of HARV, with growth of "new" different types of prostate cancer cells which set-up for later "switch" in ceramide-PI3K to survival and proliferation.
authors.affiliation: Department of Pathology & Laboratory Medicine, Tulane University Health Science Center, 1430 Tulane Ave., SL 79, New Orleans, LA 70112-2699, USA. sclejan@tulane.edu
authors.forename: S
authors.initials: S
authors.lastname: Clejan
authors.forename: K
authors.initials: K
authors.lastname: O'Connor
authors.forename: N
authors.initials: N
authors.lastname: Rosensweig
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002518:Ceramides / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004075:Diglycerides / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D008297:Male; D010743:Phospholipids / Q000378:metabolism; D011467:Prostate / Q000166:cytology* / Q000378:metabolism*; D015290:Second Messenger Systems; D013997:Time Factors; D014407:Tumor Cells, Cultured; D018474:Weightlessness Simulation
chemical_list: D002518:Ceramides; D004075:Diglycerides; D007295:Inositol Phosphates; D010743:Phospholipids; D002794:Choline