» Articles » PMID: 14563674

Inducible Antisense RNA Targeting Amino Acid Transporter ATB0/ASCT2 Elicits Apoptosis in Human Hepatoma Cells

Overview
Date 2003 Oct 18
PMID 14563674
Citations 31
Authors
Affiliations
Soon will be listed here.
Abstract

Amino acid transporter B(0)/ASC transporter 2 (ATB(0)/ASCT2) is responsible for most glutamine uptake in human hepatoma cells. Because this transporter is not expressed in normal hepatocytes, we hypothesized that its expression is necessary for growth of human liver cancer cells. To test this hypothesis, Sloan Kettering hepatoma (SK-Hep) cells were stably transfected with an inducible 1.3-kb ATB(0)/ASCT2 antisense RNA expression plasmid under the transcriptional control of mifepristone, a synthetic steroid. Induced antisense RNA expression in monolayer cultures decreased ATB(0)/ASCT2 mRNA levels by 73% and glutamine transport rates by 65% compared with controls after 24 h, leading to a 98% decrease in cell number after 48 h. Cellular death was attributable to apoptosis based on cellular blebbing, caspase-3 activation, vital dye and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, and poly-(ADP-ribose) polymerase (PARP) cleavage. Transporter knockdown also markedly increased activities of caspases-2 and -9, marginally enhanced caspase-8 activity, and dramatically increased ASCT1 mRNA levels, presumably as a futile compensatory response. Apoptosis elicited via transporter silencing was not attributable to the double-stranded RNA-dependent protein kinase R (PKR) pathway. For comparison, glutamine deprivation also caused apoptotic cell death but with slower temporal kinetics, stimulated caspases-2 and -3 but not caspases-8 or -9 activities, and led to considerable PARP cleavage. Thus ASCT2 suppression exerts proapoptotic effects transcending those of glutamine starvation alone. We conclude that ATB(0)/ASCT2 expression is necessary for SK-Hep cell growth and viability and suggest that it be further explored as a selective target for human hepatocellular carcinoma.

Citing Articles

Glutamine transporters as effective targets in digestive system malignant tumor treatment.

Chu F, Tong K, Gu X, Bao M, Chen Y, Wang B Oncol Res. 2024; 32(10):1661-1671.

PMID: 39308523 PMC: 11413814. DOI: 10.32604/or.2024.048287.


Acute heat stress-indued apoptosis in mouse skeletal muscle is not associated with alteration of glutamine homeostasis.

Chen Y, Yu T, Deuster P PLoS One. 2022; 17(11):e0278176.

PMID: 36441734 PMC: 9704566. DOI: 10.1371/journal.pone.0278176.


Insight into the interplay between mitochondria-regulated cell death and energetic metabolism in osteosarcoma.

Lai H, Naumova N, Marchais A, Gaspar N, Geoerger B, Brenner C Front Cell Dev Biol. 2022; 10:948097.

PMID: 36072341 PMC: 9441498. DOI: 10.3389/fcell.2022.948097.


A genetic mammalian proportional-integral feedback control circuit for robust and precise gene regulation.

Frei T, Chang C, Filo M, Arampatzis A, Khammash M Proc Natl Acad Sci U S A. 2022; 119(24):e2122132119.

PMID: 35687671 PMC: 9214505. DOI: 10.1073/pnas.2122132119.


Combinatorial antitumor effects of amino acids and epigenetic modulations in hepatocellular carcinoma cell lines.

Hassan Y, Helmy M, Ghoneim A Naunyn Schmiedebergs Arch Pharmacol. 2021; 394(11):2245-2257.

PMID: 34415354 DOI: 10.1007/s00210-021-02140-z.