Ganglioside GD1a regulation of caveolin-1 and Stim1 expression in mouse FBJ cells:Augmented expression of caveolin-1 and Stim1 in cells with increased GD1a content

Abstract

GD1a was previously shown responsible for regulating cell motility, cellular adhesiveness to vitronectin, phosphorylation of c-Met and metastatic ability of mouse FBJ osteosarcoma cells. To determine the particular molecules regulated by GD1a, FBJ cells were assessed for tumor-related gene expression by semi-quantitative RT-PCR. Caveolin-1 and stromal interaction molecule 1 (Stim1) expression in FBJ-S1 cells, rich in GD1a, were found to be 6 and 4 times as much, respectively, than in FBJ-LL cells devoid of GD1a. Enhanced production of caveolin-1 in protein was confirmed by Western blotting. A low-metastatic FBJ-LL cell variant, having high GD1a expression through beta1-4GalNAcT-1 (GM2/GD2 synthase) cDNA transfection (Hyuga S, et al, Int J Cancer 83: 685-91, 1999), showed enhanced production of caveolin-1 and Stim1 in mRNA and protein, compared to mock-transfectant M5. Incubation of FBJ-M5 cells with exogenous GD1a augmented the expression of caveolin-1 in mRNA and protein and Stim1 in mRNA as well. Treatment of FBJ-S1 with fumonisin B1, an inhibitor of N-acylsphinganine synthesis, for 15 days caused the complete depletion of gangliosides and suppressed the expression of caveolin-1 and Stim1. St3gal5 siRNA transfected cells showed decreased expression of caveolin-1 and Stim1 mRNA, as well as St3gal5 mRNA. These findings clearly indicate ganglioside GD1a to be involved in the regulation of the transformation suppressor genes, caveolin-1 and Stim1. Moreover, treatment with GD1a of mouse melanoma B16 cells and human hepatoma HepG2 cells brought about elevated expression of caveolin-1 and Stim1.

A Glycosphingolipid/Caveolin-1 Signaling Complex Inhibits Motility of Human Ovarian Carcinoma Cells

“…The second aspect is related to the observation that cellular ganglioside or GM3 synthase levels can regulate the expression of caveolin-1. Yamagata and co-workers (56) showed that GD1a ganglioside regulated caveolin-1 expression in FBJ mouse osteosarcoma cells. Also in that case, the concomitant increase in a certain ganglioside and in caveolin-1 seems to be related to the possible role of caveolin-1 as a tumor suppressor.…”

GM3 Signals Regulating TNF-Alpha Expression Are Mediated by Rictor and Arhgdib in Mouse Melanoma B16 Cells

“…RNA extraction and the analysis of amplified DNA were detailed in our earlier paper [25]. The primers used in this study were designed with Primer 3 software and synthesized by Shanghai Genebase Biotechnology.…”

“…Primer sequences used for PCR in this study were as follows: for eukaryotic elongation factor (eEF), sense, 5′-CGCTGCTGGAAGCTTTGGAT-3′ and antisense, 5′-GGGGCCATCTTCCAGCTTCT-3′; for TNF-α, sense, 5′-TCCAGGCGGTGCCTATGTCT-3′ and antisense, 5′-GTTTGAGCTCAGCCCCCTCA-3′; for Raptor, sense, 5′-CCGGCTGAGAGCATTGGACT-3′ and antisense, 5′-CACCCCACACCATCT- TGCAG-3′; for Rictor, sense, 5′-CAGCACCTCCACCAGCA- CAT-3′ and antisense, 5′-GGAGCTTGCTGAGCCTTCCA-3′; for Arhgdib, sense, 5′-CCAGAGACACAGGGCCGACT-3′ and antisense, 5′-GGCCTCGAGCTCGCCAGTAA-3′. mRNA of the genes under consideration and eEF mRNA as control were determined by RT-PCR semi-quantitatively, as described previously [25]. TNF-α mRNA values are expressed as a ratio of TNF-α to eEF mRNA and usually expressed as a value of 1 for control experiments.…”

Caveolae/Caveolin-1 Are Important Modulators of Store-Operated Calcium Entry in Hs578/T Breast Cancer Cells

“…Like caveolin-1, it can also bind and activate TRPC1 (22). Additionally, caveolin-1 and STIM1 expression are co-regulated in osteosarcoma cells (23).…”