Regulatory T Cells 2

Calretinin immunohistochemistry: a simple and efficient tool to diagnose Hirschsprung disease

Diagnosis of Hirschsprung disease (HD) is quite entirely based on the histopathological analysis of suction rectal biopsies. This hematoxylin and eosin approach has some limitations, despite the help of acetylcholinesterase staining. The aim of this study was to assess the diagnostic value of calretinin immunochemistry as a simple and reliable method in the diagnosis of HD. A total of 131 initial rectal biopsies carried out for suspicion of HD in children were retrieved, and calretinin immunohistochemistry was carried out on paraffin-embedded biopsies. Diagnosis of HD was made when no staining was observed. The results were statistically analyzed in comparison with our standard method (histology and acetylcholinesterase staining). 130 biopsies were accurately diagnosed on the basis of the positivity or negativity of calretinin staining. The senior pathologists diagnosed all cases of HD with no false positives. Furthermore, 12 additional cases initially considered as doubtful for HD using the standard method, were accurately diagnosed using calretinin immunohistochemistry. The false negative was a case of HD with a calretinin-positive biopsy. We also demonstrate the ease of calretinin interpretation compared with acetylcholinesterase for the junior pathologist. Calretinin immunohistochemistry overcomes most of the difficulties encountered using the combination of histology and acetylcholinesterase staining, and detects almost all cases of HD with confidence, with no false positives. Thus, we demonstrate that calretinin is superior to acetylcholinesterase to complete histology and could advantageously substitute for acetylcholinesterase.

Topoisomerase IIα mRNA and protein expression in ovarian carcinoma: correlation with clinicopathological factors and prognosis

Topoisomerase IIalpha (Top IIalpha) is a nuclear enzyme that plays a central role in DNA metabolism, and is a molecular target for a variety of chemotherapeutic agents. Top IIalpha has recently gained attention as a biomarker for therapy response and patient survival. In this study, we attempted to assess the feasibility of measuring Top IIalpha gene expression in RNA, isolated from archival formalin-fixed paraffin-embedded tissue specimens, which are used routinely in pathology laboratories. We have employed a new technique on the basis of magnetic particles' separation and purification of nucleic acids, and evaluated both protein and mRNA expressions from the same routinely processed tissue blocks. We investigated the expression of Top IIalpha mRNA and protein by real-time reverse transcription polymerase chain reaction and immunohistochemistry, in a cohort of 133 primary ovarian carcinomas, and evaluated the association between Top IIalpha expression and clincopathological variables as well as patient outcome. Elevated Top IIalpha mRNA expression was observed in high-grade tumors (P=0.003) and advanced stage disease (P=0.011). In univariate Kaplan-Meier analysis, patients with higher expression of Top IIalpha nuclear protein had a significantly decreased overall survival (P=0.045). Interestingly, we detected cytoplasmic protein expression of Top IIalpha in a subset of samples. Cytoplasmic expression of Top IIalpha was associated with the expression of chromosomal region maintenance/exportin 1 (CRM1)-a nuclear export protein (P=0.008). Our study suggests that Top IIalpha overexpression is involved in the progression of ovarian cancer in a subset of the patients. Our results encourage the further evaluation of the prognostic and predictive values of Top IIalpha expression in ovarian carcinoma, which might help to assess the patients' risk profile, and the planning of an individualized therapy.

Identification of c-kit gene mutations in primary adenoid cystic carcinoma of the salivary gland

The CD117 (KIT) protein is overexpressed in many human neoplasms including adenoid cystic carcinoma of salivary glands. To evaluate the function of c-kit-activating mutations in adenoid cystic carcinoma of the salivary gland, we studied 14 cases (13 primary, 1 cervical lymph node metastasis) from our institution. KIT protein expression was evaluated by immunohistochemistry using formalin-fixed paraffin-embedded tissue. Mutational analyses of c-kit extracellular (exon 9), juxtamembrane (exon 11) and tyrosine kinase domains (exons 13 and 17) were performed by polymerase chain reaction, clonal selection and DNA sequencing. All 14 cases demonstrated strong KIT expression by immunohistochemistry. Molecular analysis was successful in 8 of 14 cases, and c-kit missense point mutations were detected in seven of eight cases (88%) including seven in exon 11, two in exon 9, two in exon 13 and two in exon 17. Eight silent point mutations were detected in five cases. Two cases contained missense mutations in more than one exon. Different mutations were found in the primary tumor and the cervical lymph node metastasis of one patient. Point mutations in domains similar to those described in gastrointestinal stromal tumors were detected, including Pro551Leu and Lys558Glu (5' end of exon 11), Leu576Phe (3' end of exon 11), Val643Ala (exon 13) and Asn822Ser (exon 17). Additional novel point mutations in exons 9, 11, 13 and 17 were also identified. This study is the first to report c-kit gene mutations in primary adenoid cystic carcinoma of the salivary gland. Identification of such potential gain-of-function mutations in exon 11, and less frequently in exons 9, 13 and 17, suggests that KIT may be involved in the pathogenesis of adenoid cystic carcinoma of salivary glands. Our study raises a prospect of correlation of c-kit mutation and a potential treatment of adenoid cystic carcinoma with tyrosine kinase inhibitor (imatinib).

A genome-wide survey of human short-term memory

Recent advances in the development of high-throughput genotyping platforms allow for the unbiased identification of genes and genomic sequences related to heritable traits. In this study, we analyzed human short-term memory, which refers to the ability to remember information over a brief period of time and which has been found disturbed in many neuropsychiatric conditions, including schizophrenia and depression. We performed a genome-wide survey at 909 622 polymorphic loci and report six genetic variations significantly associated with human short-term memory performance after genome-wide correction for multiple comparisons. A polymorphism within SCN1A (encoding the α subunit of the type I voltage-gated sodium channel) was replicated in three independent populations of 1699 individuals. Functional magnetic resonance imaging during an n-back working memory task detected SCN1A allele-dependent activation differences in brain regions typically involved in working memory processes. These results suggest an important role for SCN1A in human short-term memory.

Identification of IFRD1 as a modifier gene for cystic fibrosis lung disease

Lung disease is the major cause of morbidity and mortality in cystic fibrosis, an autosomal recessive disease caused by mutations in CFTR. In cystic fibrosis, chronic infection and dysregulated neutrophilic inflammation lead to progressive airway destruction. The severity of cystic fibrosis lung disease has considerable heritability, independent of CFTR genotype. To identify genetic modifiers, here we performed a genome-wide single nucleotide polymorphism scan in one cohort of cystic fibrosis patients, replicating top candidates in an independent cohort. This approach identified IFRD1 as a modifier of cystic fibrosis lung disease severity. IFRD1 is a histone-deacetylase-dependent transcriptional co-regulator expressed during terminal neutrophil differentiation. Neutrophils, but not macrophages, from Ifrd1-deficient mice showed blunted effector function, associated with decreased NF-kappaB p65 transactivation. In vivo, IFRD1 deficiency caused delayed bacterial clearance from the airway, but also less inflammation and disease-a phenotype primarily dependent on haematopoietic cell expression, or lack of expression, of IFRD1. In humans, IFRD1 polymorphisms were significantly associated with variation in neutrophil effector function. These data indicate that IFRD1 modulates the pathogenesis of cystic fibrosis lung disease through the regulation of neutrophil effector function.

New common variants affecting susceptibility to basal cell carcinoma

In a follow-up to our previously reported genome-wide association study of cutaneous basal cell carcinoma (BCC), we describe here several new susceptibility variants. SNP rs11170164, encoding a G138E substitution in the keratin 5 (KRT5) gene, affects risk of BCC (OR = 1.35, P = 2.1 x 10(-9)). A variant at 9p21 near CDKN2A and CDKN2B also confers susceptibility to BCC (rs2151280[C]; OR = 1.19, P = 6.9 x 10(-9)), as does rs157935[T] at 7q32 near the imprinted gene KLF14 (OR = 1.23, P = 5.7 x 10(-10)). The effect of rs157935[T] is dependent on the parental origin of the risk allele. None of these variants were found to be associated with melanoma or fair-pigmentation traits. A melanoma- and pigmentation-associated variant in the SLC45A2 gene, L374F, is associated with risk of both BCC and squamous cell carcinoma. Finally, we report conclusive evidence that rs401681[C] in the TERT-CLPTM1L locus confers susceptibility to BCC but protects against melanoma.

Genome-wide association study identifies variants in the ABO locus associated with susceptibility to pancreatic cancer

We conducted a two-stage genome-wide association study of pancreatic cancer, a cancer with one of the lowest survival rates worldwide. We genotyped 558,542 SNPs in 1,896 individuals with pancreatic cancer and 1,939 controls drawn from 12 prospective cohorts plus one hospital-based case-control study. We conducted a combined analysis of these groups plus an additional 2,457 affected individuals and 2,654 controls from eight case-control studies, adjusting for study, sex, ancestry and five principal components. We identified an association between a locus on 9q34 and pancreatic cancer marked by the SNP rs505922 (combined P = 5.37 x 10(-8); multiplicative per-allele odds ratio 1.20; 95% confidence interval 1.12-1.28). This SNP maps to the first intron of the ABO blood group gene. Our results are consistent with earlier epidemiologic evidence suggesting that people with blood group O may have a lower risk of pancreatic cancer than those with groups A or B.

Genome-wide association study identifies variants at CLU and CR1 associated with Alzheimer's disease

The gene encoding apolipoprotein E (APOE) on chromosome 19 is the only confirmed susceptibility locus for late-onset Alzheimer's disease. To identify other risk loci, we conducted a large genome-wide association study of 2,032 individuals from France with Alzheimer's disease (cases) and 5,328 controls. Markers outside APOE with suggestive evidence of association (P < 10(-5)) were examined in collections from Belgium, Finland, Italy and Spain totaling 3,978 Alzheimer's disease cases and 3,297 controls. Two loci gave replicated evidence of association: one within CLU (also called APOJ), encoding clusterin or apolipoprotein J, on chromosome 8 (rs11136000, OR = 0.86, 95% CI 0.81-0.90, P = 7.5 x 10(-9) for combined data) and the other within CR1, encoding the complement component (3b/4b) receptor 1, on chromosome 1 (rs6656401, OR = 1.21, 95% CI 1.14-1.29, P = 3.7 x 10(-9) for combined data). Previous biological studies support roles of CLU and CR1 in the clearance of beta amyloid (Abeta) peptide, the principal constituent of amyloid plaques, which are one of the major brain lesions of individuals with Alzheimer's disease.

Erratum: Corrigendum: Eradication of acute promyelocytic leukemia-initiating cells through PML-RARA degradation