Apoptosis of human breast carcinoma cells in the presence of cis-platin and L-/D-PPMP: IV. Modulation of replication complexes and glycolipid: Glycosyltransferases

Abstract

Apoptosis of human breast carcinoma cells (SKBR-3, MCF-7, and MDA-468) has been observed after treatment of these cells with anti-cancer drug cis-platin and glycosphingolipid biosynthesis inhibitor L- and D-PPMP, respectively. These drugs initiated apoptosis in a dose-dependent manner as measured by phenotypic morphological changes, by binding of a fluorescent phophatidyl serine-specific dye (PSS-380) onto the outer leaflet of the cell membranes, and by activation of caspases, -3, -8, and -9. It was observed that in two hours very little apoptotic process had started but predominant biochemical changes occurred after 6 h. DNA degradation started after 24 hours of drug treatment. However, very little is known about the stability of the ';Replication Complexes'' during the apoptotic process. DNA helicases are motor proteins that catalyze the melting of genomic DNA during its replication, repair, and recombination processes. Previously, DNA helicase-III was characterized as a component of the replication complexes isolated from embryonic chicken brains as well as breast and colon carcinoma cells. Helicase activities were measured by a novel method (ROME assay), and DNA polymerase-alpha activities were determined by regular chain extension of the nicked ACT-DNA, by determining values obtained from +/- aphidicolin-treated incubation mixtures. In all three breast carcinoma cell lines, a common trend was observed: a decrease of activities of DNA polymerase-alpha and Helicase III. A sharp decrease of activities of the glycolipid sialyltransferases: SAT-2 (CMP-NeuAc; GD3 alpha2-8 sialyltransferase) and SAT-4 (CMP-NeuAc: GM1a alpha2-3 sialyltransferase) was observed in the apoptotic carcinoma cells treated with L-PPMP compared with cis-platin.

Direct quantitative determination of ceramide glycosylation in vivo: a new approach to evaluate cellular enzyme activity of glucosylceramide synthase

“…4A , left panel). D -threo -PDMP, a specifi c inhibitor of GCS enzyme ( 42,43 ), signifi cantly decreased NBD C6-GlcCer ( Fig. 4A , left panel) and endogenous GlcCer ( Fig.…”

Apoptosis of Breast Cancer Cells: Modulation of Genes for Glycoconjugate Biosynthesis and Targeted Drug Delivery

“…Using highly metastatic breast carcinoma cells (SKBR-3, MDA-468, and MCF-7), we have reported in recent years (Basu et al 2004a, b, c ;Ma et al 2004 ;Boyle et al 2006 ) apoptotic induction by d -/ l -PPMP, d -PDMP (inhibitors of GSL biosynthesis), cisplatin (inhibitor of DNA biosynthesis), betulinic acid (a triterpenoid used as an anticancer agent in China as an alternative medicine), tamoxifen (a common anticancer agent used for the treatment of breast cancers today), GD3, GD1b, and melphalan (a scrambler for Golgi bodies) in the range of 2-16 m M concentrations (Fig. 16.2 ) (Basu et al 2004a, b, c ;Ma et al 2004 ;Boyle et al 2006 ) .…”

“…16.2 ) (Basu et al 2004a, b, c ;Ma et al 2004 ;Boyle et al 2006 ) . Inhibition of cell growth (IC-50) was different with three different metastatic breast cancer cell lines when tested with a single apoptotic agent ( l -PPMP) for 24 h (Boyle et al 2006 ) . All these chemicals ( Fig.…”

“…On the other hand, cisplatin (used in the treatment of testicular cancers) induced apoptosis ( Fig. 16.3 ) (Basu et al 2004a ) occurs in those cell lines at much higher concentrations (50-150 m M) (Boyle et al 2006 ) by EBRAP followed by activation of caspase-8 ( Fig. 16.3 ) Several new chemicals have been tested in recent years for induction of the apoptotic process by activating IMCAP (internal mitochondrial caspase activating pathway), NF-kappaB (NFKBAP), EBRAP (external Bad-receptor activating pathway), or CPKAP pathway (Yuan et al 2011 ;Leung et al 2011 ;Ullah et al 2011 ;Marchetti et al 2011 ;Kim et al 2010 ;Laezza et al 2010 ;Wesierska et al 2011 ;Chou et al 2010 ;Zhang et al 2010 ;Patil et al 2010 ;Banerjee et al 2010 ;Shirure et al 2011 ;Cazet et al 2010 ) .…”

“…However, apoptotic mechanism of MCF-7 cell by cisplatin or l -PPMP is still unknown (Basu et al 2004b, c ;Boyle et al 2006 ;Yuan et al 2011 ;Leung et al 2011 ;Ullah et al 2011 ;Marchetti et al 2011 ;Kim et al 2010 ;Laezza et al 2010 ;Wesierska et al 2011 ;Chou et al 2010 ;Zhang et al 2010 ;Patil et al 2010 ) . Quercetin (a natural polyphenolic compound) induced apoptosis in many human cancer cells, including MCF-7 human breast cancer cells (Chou et al 2010 ) .…”