heterozygosity Dotaz Zobrazit nápovědu
BACKGROUND: Lung carcinogenesis is a multistep process of accumulation of genetic changes, including loss of heterozygosity (LOH), and precedes phenotypic transformation of the bronchial mucosa. The activity of telomerase, correlating with the hTERT mRNA expression, is detectable in a majority of neoplasms. In this study, the frequency of LOH and hTERT expression in bronchial mucosa of heavy smokers in bronchoscopic biopsies was analyzed. METHODS: LOH was examined in 122 bronchial specimens from 81 smokers (67 normal mucosa/bronchitis, 12 squamous metaplasia, 28 dysplasia, 15 bronchogenic carcinoma specimens) by polymerase chain reaction (PCR) and capillary electrophoresis by using 7 fluorescence-labeled markers matching 5 chromosomal regions. hTERT expression was analyzed in 87 specimens (45 normal mucosa/bronchitis, 12 squamous metaplasia, 18 dysplasia, 12 bronchogenic carcinoma specimens) by real-time quantitative reverse-transcription PCR. RESULTS: LOH was detected in at least 1 chromosomal region in 51 of 122 (41.8%) specimens; the incidence in normal bronchial mucosa and preneoplastic lesions was similar (20%-40%); a substantial rise (87%) occurred in carcinomas. The median normalized hTERT(N) values were 6.67 in normal epithelium/chronic bronchitis, 18.38 in squamous metaplasia, 13.31 in epithelial dysplasia, and 75.46 in carcinomas. These results were significantly different (P=.0036). With an increasing number of LOH, the median value of hTERT(N) expression rose, but hTERT was expressed also in tissue samples without any LOH detection. CONCLUSIONS: Results indicated that hTERT expression, together with LOH, represent early events in lung carcinogenesis, as both were detected in precancerous lesions and in normal epithelium of heavy smokers.
- MeSH
- bronchogenní karcinom enzymologie genetika MeSH
- bronchy metabolismus patologie MeSH
- epitelové buňky metabolismus patologie MeSH
- financování organizované MeSH
- kouření genetika MeSH
- lidé MeSH
- messenger RNA metabolismus MeSH
- metaplazie MeSH
- nádory plic enzymologie genetika MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- prekancerózy metabolismus patologie MeSH
- sliznice metabolismus patologie MeSH
- telomerasa genetika metabolismus MeSH
- ztráta heterozygozity MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
INTRODUCTION: Ductal carcinoma in situ (DCIS) is considered to be related to the development of invasive breast cancer. The aim of molecular biological research of preinvasive breast lesion characteristics and comparison with normal tissues and tissue of invasive tumours is to identify patients at high risk of developing invasive tumour on the basis of already established preinvasive lesions, and thus influence clinical decision-making. The aim of our study was to analyse several key molecules involved in different cellular pathways important for cancer development and progression in different types of breast tissue and to describe similarities and differences between premalignant and malignant lesions. MATERIAL AND METHODS: Genetic material isolated from both the tumour and healthy tissue was examined by loss of heterozygosity (LOH) analysis and real-time PCR using collagen 2A as a house-keeping gene. RESULTS: We analysed 65 samples of healthy mammary gland, 25 DCIS and 42 invasive ductal breast cancer samples. We analysed the LOH in three genes: BRCA1, BRCA2 and p53; and the gene expression of the VEGF gene and Bcl-2 gene. LOH in the BRCA1 gene was present in 44.74% of invasive samples and in 8.69% of DCIS (p=0.026); LOH in the BRCA2 gene in 45.0% of invasive samples and in 9.52% of DCIS (p=0.036); LOH in the p53 gene in 32.5% of invasive samples and in 31.82% of DCIS (p=0.97). No LOH was observed in normal tissue samples. VEGF was overexpressed in 14.3% of invasive cancers and in 12.0% of DCIS. Overexpression of Bcl-2 was observed in 11.9% of invasive cancers and in 8.0% of DCIS. CONCLUSION: We have confirmed that some of the molecular characteristics of DCIS are identical to those of invasive carcinoma. This approach could lead to the identification of molecular markers as indicators for the potential development of DCIS into invasive carcinoma or identification of DCIS subgroups with latent invasion.
- MeSH
- duktální karcinom prsu genetika patologie MeSH
- geny bcl-2 MeSH
- geny BRCA1 MeSH
- geny BRCA2 MeSH
- geny p53 MeSH
- intraduktální neinfiltrující karcinom genetika patologie MeSH
- invazivní růst nádoru MeSH
- lidé MeSH
- mutační analýza DNA MeSH
- nádory prsu genetika patologie MeSH
- regulace genové exprese u nádorů MeSH
- stanovení celkové genové exprese MeSH
- ztráta heterozygozity genetika MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Complex karyotypes are seen in approximately 20% of patients with myelodysplastic syndromes (MDS) and are associated with a high risk of transformation to acute myeloid leukemia and poor outcomes in patients. Copy number neutral loss of heterozygosity (CN-LOH, i.e., both copies of a chromosomal pair or their parts originate from one parent) might contribute to increased genomic instability in the bone-marrow cells of patients with MDS. The pathological potential of CN-LOH, which arises as a clonal aberration in a proportion of somatic cells, consists of tumor suppressor gene and oncogene homozygous mutations. The aim of our study was to evaluate the frequency of CN-LOH at 17p in bone-marrow cells of newly diagnosed MDS patients with complex chromosomal aberrations and to assess its correlation with mutations in the TP53 gene (17p13.1). CN-LOH was detected in 40 chromosomal regions in 21 (29%) of 72 patients analyzed. The changes in 27 of the 40 regions identified were sporadic. The most common finding was CN-LOH of the short arm of chromosome 17, which was detected in 13 (18%) of 72 patients. A mutational analysis confirmed the homozygous mutation of TP53 in all CN-LOH 17p patients, among which two frameshift mutations are not registered in the International Agency for Research on Cancer TP53 Database. CN-LOH 17p correlated with aggressive disease (median overall survival 4 months) and was strongly associated with a complex karyotype in the cohort studied, which might cause rapid disease progression in high-risk MDS. No other CN-LOH region previously recorded in MDS or AML patients (1p, 4q, 7q, 11q, 13q, 19q, 21q) was detected in our cohort of patients with complex karyotype examined at the diagnosis of MDS. The LOH region appeared to be balanced (i.e., with no DNA copy number change) when examined with conventional and molecular cytogenetic methods. Therefore, a microarray that detects single-nucleotide polymorphisms is an ideal method with which to identify and further characterize CN-LOH. Our data should specify the prognosis and should lead to the identification of potential targets for therapeutic interventions.
- MeSH
- chromozomální aberace * MeSH
- dospělí MeSH
- genová dávka * MeSH
- hybridizace in situ fluorescenční MeSH
- jednonukleotidový polymorfismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy, pár 17 genetika MeSH
- mutace MeSH
- mutační analýza DNA MeSH
- myelodysplastické syndromy genetika MeSH
- nádorový supresorový protein p53 genetika MeSH
- retrospektivní studie MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- variabilita počtu kopií segmentů DNA MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- ztráta heterozygozity genetika MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Úvod: Vstup viru lidské imunitní nedostatečnosti typu 1 (HIV-1) do cílových buněk je umožněn CD4 receptorem a jedním ze dvou koreceptorů CXCR4 nebo CCR5. Delece úseku 32 nukleotidů v genu pro CCR5 (CCR5Δ32) v obou alelách poskytuje silnou, avšak ne absolutní odolnost proti infekci HIV-1 a delece v jedné alele zpomaluje postup nemoci směřující k rozvinutí AIDS. Zde jsme analyzovali prevalenci a roli heterozygotního výskytu CCR5Δ32 na postup onemocnění u HIV pozitivních jedinců v České republice. Metody: Celkem 92 HIV-1 séropozitivních osob včetně 80 Čechů z AIDS centra v Nemocnici Na Bulovce v Praze bylo zařazeno do genotypizace CCR5, která byla součástí studie role HIV fitness na průběh onemocnění. Z periferních mononukleárních buněk pacienta byla získána DNA, která byla použita k amplifikaci pomocí PCR v reálném čase použitím specifických sond, které detekovaly divokou variantu CCR5 a variantu s 32 nt delecí. Podmnožina 74 pacientů bez antiretrovirové léčby, kteří byli sledováni déle než jeden rok, byla použita k určení role heterozygotního fenotypu CCR5 na průběh nemoci. Výsledky: Heterozygotní CCR5Δ32 varianta byla nalezena u 23,8 % z 80 českých HIV-1 séropozitivních osob, což je velmi podobné jako publikovaná 21 % a 24 % prevalence u HIV negativní české populace. Homozygotní mutovaná varianta nebyla nalezena. U skupiny osob s heterozygotním CCR5 fenotypem jsme pozorovali slabě zvýšený průměrný počet CD4-pozitivních T-lymfocytů a nižší průměrné hodnoty virémie v plazmě. Závěr: Celkově, naše studie neukázala žádný zřejmý užitek přítomnosti heterozygotní CCR5Δ32 varianty na přenos HIV a pouze malý užitek na průběh nemoci u české HIV-1 pozitivní kohorty.
Background: Entry of human immunodeficiency virus type 1 (HIV-1) in target cells is enabled by CD4 receptor and one of two co-receptors, CXCR4 or CCR5. Deletion of 32 bp in CCR5 gene (CCR5Δ32) in both alleles provides strong but not absolute resi-stance to HIV-1 infection and deletion in one allele slows disease progression to AIDS. Here, we analyzed the prevalence and the role of CCR5Δ32 heterozygosity on the disease progression in HIV positive patients in the Czech Republic. Patients and methods: A total of 92 HIV-1 seropositive subjects that included 80 Czech individuals from the AIDS center in the Hospital Na Bulovce in Prague were enrolled in CCR5 genoty-ping as a part of a study of the role of HIV fitness on disease progression. DNA was extracted from patient’s peripheral blood mononuclear cells and subjected to real-time PCR with specific probes detecting wild-type and 32 bp-deleted CCR5 variants. A subgroup of 74 antiretroviral therapy-naive patients with more than one year of follow-up was used to determine the role of the CCR5Δ32 heterozygous phenotype in disease progression. Results: CCR5Δ32 was found heterozygous in 23.8% of 80 Czech HIV-1 seropositive individuals which is very similar to 21% and 24% prevalence reported in HIV negative Czech population. Homozygous mutant variant was not detected. In CCR5Δ32 he-terozygous group we observed slightly higher mean CD4+ T-cell count and lower mean plasma viremia levels.Conclusions: Overall, our study indicates no obvious benefit of CCR5Δ32 heterozygosity on HIV transmission and only small benefit on disease progression in the Czech HIV-1 cohort.
- MeSH
- genotypizační techniky MeSH
- HIV-1 * genetika izolace a purifikace MeSH
- kohortové studie MeSH
- lidé MeSH
- polymorfismus genetický MeSH
- progrese nemoci MeSH
- receptory CCR5 genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
