Histology and CHD5 expression in xenografts derived from NLF and IMR5 cells transfected with either CHD5 sense or CHD5 antisense constructs

) Histology of NLF and IMR5 xenograft tumors (see ) after 5 weeks of growth. NLF--AS tumors were composed of undifferentiated cells with scant cytoplasm (top left), whereas NLF- tumors showed areas of necrosis () and differentiation (; top right). Cells in the IMR5--AS tumors were undifferentiated (bottom left), whereas cells in the IMR5- tumors had a more elongated appearance (bottom right). Bar = 20 μm. ) Relative expression of CHD5, normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was determined by real-time reverse transcription–polymerase chain reaction in parental NLF and IMR5 cell lines, as well as the CHD5 sense and CHD5 antisense transfected lines used for the xenograft experiments. The normalized values indicated by each bar graph represent the mean of three measurements. Replicate measurements were within 10% of the mean for each bar shown. ) Expression of CHD5 protein, as detected by immunoblotting, is shown for the NLF and IMR5 parental lines and the corresponding sense- and antisense-transfected cells used in these experiments.<p><b>Copyright information:</b></p><p>Taken from ", a Tumor Suppressor Gene Deleted From 1p36.31 in Neuroblastomas"</p><p></p><p>JNCI Journal of the National Cancer Institute 2008;100(13):940-949.</p><p>Published online 2 Jul 2008</p><p>PMCID:PMC2483574.</p><p></p

Effect of altered CHD5 expression on clonogenicity in neuroblastoma cell lines

Plasmids containing CHD5 or antisense CHD5 (CHD5-AS) were stably transfected into NLF and IMR5 neuroblastoma cell lines, both of which have hemizygous 1p deletion and amplification, and into SK-N-SH and SK-N-FI neuroblastoma cell lines, which have neither. Transfected cells were plated on soft agar, and colonies were counted 3 weeks later. ) NLF cells. CHD5 vs CHD5-AS, < .001. ) IMR5 cells. CHD5 vs CHD5-AS, = .001. ) SK-N-SH cells. CHD5 vs CHD5-AS, = .16. ) SK-N-FI cells. CHD5 vs CHD5-AS, = .10. Means and 95% confidence intervals () are shown. values (two-sided) were calculated using the Student test. Data are representative of three independent experiments performed in quadruplicate.<p><b>Copyright information:</b></p><p>Taken from ", a Tumor Suppressor Gene Deleted From 1p36.31 in Neuroblastomas"</p><p></p><p>JNCI Journal of the National Cancer Institute 2008;100(13):940-949.</p><p>Published online 2 Jul 2008</p><p>PMCID:PMC2483574.</p><p></p

Methylation of the CHD5 promoter and 5′ coding region in four neuroblastoma cell lines

–) CHD5 promoter methylation in NLF () and IMR5 () cells, both of which have hemizygous 1p deletions and virtually no CHD5 expression. –) CHD5 promoter methylation in SK-N-SH () and SK-N-FI cells (), which lack 1p deletion and have low expression of CHD5. Methylation at a given GC dinucleotide, as determined by methylation-specific sequencing, is shown as a percentage of sequences analyzed (10 per site). Methylation was determined as the number of clones with methylation of the given region divided by 10 and is expressed as a percentage.<p><b>Copyright information:</b></p><p>Taken from ", a Tumor Suppressor Gene Deleted From 1p36.31 in Neuroblastomas"</p><p></p><p>JNCI Journal of the National Cancer Institute 2008;100(13):940-949.</p><p>Published online 2 Jul 2008</p><p>PMCID:PMC2483574.</p><p></p

Association of CHD5 expression with risk factors and outcome in primary neuroblastomas

) Normalized CHD5 expression in 101 primary neuroblastomas stratified based on the presence (n = 26) or absence (n = 75) of 1p deletion (two-sample test, < .001). ) Association of normalized CHD5 expression with the risk group (low, intermediate, high, and ultrahigh) as defined above and in (). Briefly, for this study, low-risk patients were defined as infants (<p><b>Copyright information:</b></p><p>Taken from ", a Tumor Suppressor Gene Deleted From 1p36.31 in Neuroblastomas"</p><p></p><p>JNCI Journal of the National Cancer Institute 2008;100(13):940-949.</p><p>Published online 2 Jul 2008</p><p>PMCID:PMC2483574.</p><p></p

A Txnrd1-dependent metabolic switch alters hepatic lipogenesis, glycogen storage, and detoxification

Besides helping to maintain a reducing intracellular environment, the thioredoxin (Trx) system impacts bioenergetics and drug-metabolism. We show that hepatocyte-specific disruption of Txnrd1, encoding Trx reductase-1 (TrxR1), causes a metabolic switch in which lipogenic genes are repressed and periportal hepatocytes become engorged with glycogen. These livers also overexpress machinery for biosynthesis of glutathione and conversion of glycogen into UDP-glucuronate; they stockpile glutathione-S-transferases and UDP-glucuronyl-transferases; and they overexpress xenobiotic exporters. This realigned metabolic profile suggested that the mutant hepatocytes might be preconditioned to more effectively detoxify certain xenobiotic challenges. Hepatocytes convert the pro-toxin acetaminophen (APAP, paracetamol) into cytotoxic N-acetyl-p-benzoquinone imine (NAPQI). APAP defenses include glucuronidation of APAP or glutathionylation of NAPQI, allowing removal by xenobiotic exporters. We found that NAPQI directly inactivates TrxR1, yet Txnrd1-null livers were resistant to APAP-induced hepatotoxicity. Txnrd1-null livers did not have more effective gene expression responses to APAP challenge; however their constitutive metabolic state supported more robust GSH biosynthesis-, glutathionylation-, and glucuronidation-systems. Following APAP challenge, this effectively sustained the GSH system and attenuated damage