Post-translational and transcriptional regulation of glycolipid glycosyltransferase genes in apoptotic breast carcinoma cells: VII. Studied by DNA-microarray after treatment with l-PPMP

Abstract

Functions of glycosphingolipids on the eukaryotic cell membranes during the onset of oncogenic processes and cell death are not well understood. Inhibitors of glycosphingolipid biosynthesis were recently found to trigger apoptosis in many carcinoma including breast cancer SKBR-3, MCF-7, and MDA-468 cells through either intrinsic or extrinsic apoptotic pathways as we previously reported. These anti-cancer inhibitors could increase ceramide concentration by blocking functions of glycolipid glycosyltransferases (GLTs). In this study, using a novel fluorescent dye (ASK-0) revealed the damage of cell organelle membranes by an inhibitor of glucosylceramide biosynthesis (L-PPMP). A highly drug- and cell-dependent regulation of MAPKs was also found by cis-platin and L-PPMP when inducing apoptosis in SKBR-3, MCF-7, and MDA-468 cells. A dose and time-dependent regulation of GLTs were investigated by enzymatic assay and DNA microarray analyses. These GLTs are involved in biosynthesis of Le(X) and sialosyl-Le(X) (neolactosyl-ceramide series) such as GalT-4 (UDP-Gal: LcOse3cer beta-galactosyltransferase, GalT-5 (UDP-Gal: nLcOse4Cer alpha1, 3galactosyltransferase, FucT-3 (GDP-Fucose: LM1 alpha1, 4fucosyltransferase). A similar effect was observed with the GLTs involved in the biosyntheses of Gg-series gangliosides, such as SAT-4 (CMP-NeuAc: GgOse4Cer alpha2, 3sialyltransferase, and SAT-2 (CMP-NeuAc: GM3 alpha2, 8sialyltransferase). The glycol-related gene DNA-microarrays also suggested the transcriptional regulation of several GLTs involved in the biosynthesis of neolactosylceramide containing cell-surface antigens in these apoptotic breast carcinoma cells. In the early apoptotic stages (2 to 6 h after L-PPMP treatment) in addition to GlcT-1 gene, several genes (betaGalTs and betaGlcNAcTs) in the SA-Le(a) pathway were stimulated.

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

“…Activation of mitochondria and release of mitochondrial apoptogenic factors by betulinic acid (BA), a melanoma-speci fi c cytotoxic agent in neuroectodermal tumors such as neuroblastoma, medulloblastoma, and Ewing's sarcoma, was fi rst recognized by Fulda and his associates (Li et al 2010b ) . In recent years, we have demonstrated that BA activates the apoptotic pathway via IMCAP in human breast carcinoma cells: SKBR-3, MDA-468, and MCF-7 also (Basu et al 2004b ;Ma et al 2009Ma et al , 2011Kessler et al 2007b ) . Whether these cells also regulate cell surface GSL biosynthesis is not known and is under investigation.…”

“…16.4 ) (Basu 1991 ;Basu et al 1999Basu et al , 2000Kaufman et al 1968 ) and LD1a were established before in embryonic chicken brain cells. GD3 ganglioside as a proapoptotic agent has been established in recent years (Ma et al , 2009(Ma et al , 2011Basu et al 2004b ;Kessler et al 2007b ;Malisan and Testi 2002a, b ) . We have employed the disialosyl gangliosides (GD3 and GD1b) to induce apoptosis (Ma et al , 2009(Ma et al , 2011Basu et al 2004b ;Kessler et al 2007b ) in human breast cancer cells, SKBR-3 grown in culture.…”

“…GD3 ganglioside as a proapoptotic agent has been established in recent years (Ma et al , 2009(Ma et al , 2011Basu et al 2004b ;Kessler et al 2007b ;Malisan and Testi 2002a, b ) . We have employed the disialosyl gangliosides (GD3 and GD1b) to induce apoptosis (Ma et al , 2009(Ma et al , 2011Basu et al 2004b ;Kessler et al 2007b ) in human breast cancer cells, SKBR-3 grown in culture. Apoptosis induction was monitored by the concomitant appearance of activated caspase-3 and by binding of PS-380 to the outer lea fl et of phosphatidyl serine (Fig.…”

“…Apoptosis induction was monitored by the concomitant appearance of activated caspase-3 and by binding of PS-380 to the outer lea fl et of phosphatidyl serine (Fig. 16.5 ) (Ma et al 2009(Ma et al , 2011Kessler et al 2007b ) . These results indicated that, in addition to many unknown GSLs on the cancer cell surfaces disialosylgangliosides (GD3 or GD1b) could be employed as a breast cancer killing therapeutic agent (Kessler et al 2007b ) .…”

“…These results indicated that, in addition to many unknown GSLs on the cancer cell surfaces disialosylgangliosides (GD3 or GD1b) could be employed as a breast cancer killing therapeutic agent (Kessler et al 2007b ) . Posttranslational and transcriptional regulation of GSL biosynthesizing genes during the induction of apoptosis by l -PPMP in breast cancer cells has been published in recent years (Ma et al 2009(Ma et al , 2011Kessler et al 2007b ) . However, exact regulations of GLT-genes in disialosylganglioside induced apoptosis of breast cancer cells are not known yet.…”