title: Apoptosis of human carcinoma cells in the presence of inhibitors of glycosphingolipid biosynthesis: I. Treatment of Colo-205 and SKBR3 cells with isomers of PDMP and PPMP.
abstract: Apoptosis, or programmed cell death, plays an important role in many physiological and diseased conditions. Induction of apoptosis in cancer cells by anti-cancer drugs and biosynthetic inhibitors of cells surface glycolipids in the human colon carcinoma cells (Colo-205) are of interest in recent years. In our present studies, we have employed different stereoisomers of PPMP and PDMP (inhibit GlcT-glycosyltransferase (GlcT-GLT)) to initiate apoptosis in Colo-205 cells grown in culture in the presence of (3)H-TdR and (3)H/or (14)C-L-Serine. Our analysis showed that the above reagents (between 1 to 20 microM) initiated apoptosis with induction of Caspase-3 activities and phenotypic morphological changes in a dose-dependent manner. We have observed an increase of radioactive ceramide formation in the presence of a low concentration (1-4 microM) of these reagents in these cell lines. However, high concentrations (4-20 microM) inhibited incorporation of radioactive serine in the higher glycolipids. Colo-205 cells were treated with L-threo-PPMP (0-20 microM) and activities of different GSL: GLTs were estimated in total Golgi-pellets. The cells contained high activity of GalT-4 (UDP-Gal: LcOse3Cer beta 1-4galactosyltransferase), whereas negligible activity of GalT-3 (UDP-Gal: GM2 beta 1-3galactosyltransferase) or GM2-synthase activity of the ganglioside pathway was detected. Previously, GLTs involved in the biosynthetic pathway of SA-Le(x) formation had been detected in these colon carcinoma (or Colo-205) cells (Basu M et al. Glycobiology 1, 527-35 (1991)). However, during progression of apoptosis in Colo-205 cells with increasing concentrations of L-PPMP, the GalT-4 activity was decreased significantly. These changes in the specific activity of GalT-4 in the total Golgi-membranes could be the resultant of decreased gene expression of the enzyme.
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA. sbasu@nd.edu
authors.forename: Subhash
authors.initials: S
authors.lastname: Basu
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.forename: Brian
authors.initials: B
authors.lastname: Mikulla
authors.forename: Mathew
authors.initials: M
authors.lastname: Bradley
authors.forename: Christopher
authors.initials: C
authors.lastname: Moulton
authors.forename: Manju
authors.initials: M
authors.lastname: Basu
authors.forename: Sipra
authors.initials: S
authors.lastname: Banerjee
authors.forename: Jin-ichi
authors.initials: J
authors.lastname: Inokuchi
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D002250:Carbon Radioisotopes; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002518:Ceramides / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006028:Glycosphingolipids / Q000096:biosynthesis*; D006801:Humans; D008614:Meperidine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D009025:Morpholines / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology*; D012694:Serine / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: D000970:Antineoplastic Agents; D002250:Carbon Radioisotopes; D002518:Ceramides; D004791:Enzyme Inhibitors; D006028:Glycosphingolipids; D009025:Morpholines; C026733:4-propionyloxy-4-phenyl-N-methylpiperidine; D012694:Serine; C033110:RV 538; D008614:Meperidine; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases