Clonality analysis of giant cell lesions of the jaws

Despite the importance of clonality to understand the pathogenesis and progression of tumors, it has not been investigated yet in giant cell lesions of the jaws. The aim of this study was to analyze the clonality of peripheral giant cell lesions (PGCL) and central giant cell lesions (CGCL) of the jaws. Six samples of PGCL and 5 samples of CGCL were analyzed in this study using the polymorphic human androgen receptor locus (HUMARA) assay. Three out of the 5 samples of the CGCL and 3 out of 6 samples of PGCL exhibited a monoclonal pattern. Our findings demonstrate that some giant cell lesions of the jaws are clonal, which indicate that these lesions may have a common genetic mechanism of development. Further studies are necessary to better elucidate the molecular mechanisms involved in the pathogenesis of such lesions.

Apesar da importância que a clonalidade das lesões tem para o entendimento da patogênese e progressão dos tumores, ainda não foi feita essa investigação em lesões de células gigantes dos maxilares. O objetivo desse trabalho foi analisar a natureza clonal de lesões periféricas de células gigantes (LPCG) e de lesões centrais de células gigantes (LCCG). Foram analisadas nesse estudo 6 amostras de LPCG e 5 amostras de LCCG, sendo todas elas provenientes de pacientes do sexo feminino. Para essa investigação foi utilizado o método baseado na região polimórfica do exon um do gene humano para oreceptor de andrógeno (HUMARA). Três das 5 amostras de LCCG e 3 das 6 amostras de LPCG exibiram um padrão monoclonal. Nossos resultados demonstram que algumas lesões de células gigantes dos maxilares apresentam uma natureza monoclonal indicando que essas lesões podem ter um mecanismo genético comum de desenvolvimento. Outros estudos são necessários para uma maior compreensão dos mecanismos moleculares envolvidos na patogênese dessas lesões.

Cryptic mosaicism involving a second chromosome X in patients with Turner syndrome

The high abortion rate of 45,X embryos indicates that patients with Turner syndrome and 45,X karyotype could be mosaics, in at least one phase of embryo development or cellular lineage, due to the need for the other sex chromosome presence for conceptus to be compatible with life. In cases of structural chromosomal aberrations or hidden mosaicism, conventional cytogenetic techniques can be ineffective and molecular investigation is indicated. Two hundred and fifty patients with Turner syndrome stigmata were studied and 36 who had female genitalia and had been cytogenetically diagnosed as having "pure" 45,X karyotype were selected after 100 metaphases were analyzed in order to exclude mosaicism and the presence of genomic Y-specific sequences (SRY, TSPY, and DAZ) was excluded by PCR. Genomic DNA was extracted from peripheral blood and screened by the human androgen receptor (HUMARA) assay. The HUMARA gene has a polymorphic CAG repeat and, in the presence of a second chromosome with a different HUMARA allele, a second band will be amplified by PCR. Additionally, the CAG repeats contain two methylation-sensitive HpaII enzyme restriction sites, which can be used to verify skewed inactivation. Twenty-five percent (9/36) of the cases showed a cryptic mosaicism involving a second X and approximately 14 percent (5/36), or 55 percent (5/9) of the patients with cryptic mosaicism, also presented skewed inactivation. The laboratory identification of the second X chromosome and its inactivation pattern are important for the clinical management (hormone replacement therapy, and inclusion in an oocyte donation program) and prognostic counseling of patients with Turner syndrome.

Polymorphism and forensic efficiency of 5X-STR loci in Korean / 대한법의학회지

This study intends to examine the polymorphism of 5 STR loci inX-chromosome (GATA172D05, HPRTB, DXS8377, DXS101, HumARA) and to evaluate usefulness of them in forensic identification. 100 unrelated Korean men and women were selected. DNA was extracted from these sample and PCR was performed to amplify it. And using automated DNA sequencer and computer program, the genotype and allele frequency of them were investigated and analyzed. The following results were obtained: 1. The genetic analysis of 5 STR loci inX-chromosome was performed with quadruplex PCR for GATA172D05, HPRTB, DXS8377, HumARA and monoplex PCR for DXS101. 2. Polymorphism information content of 5 loci is higher than 0.5, the high information content is observed. The heterozygosity is higher in DXS8377, DXS101, HumARA than others. 3. The power of discrimination is revealed high in all 5 loci in women, but in men DXS8377 and HumARA is higher than others. 4. The mean exclusion chance is revealed high in DXS8377 and HumARA which have more alleles than others in trio case and motherless case. 5. The difference of allele frequency is observed with other population group in DXS8377, DXS101, HumARA of Korean population group. Based on the results of this study, the allele frequency and population data of 5 STR loci inX-chromosome may be useful in forensic investigation.

Clonal Analysis of Neurofibroma by PCR Amplification of HUMARA Gene

BACKGROUND: While neurofibromas have generally been regarded as polyclonal hyperplastic lesions, it remains unclear whether the tumor is a true neoplasm or a hyperplastic lesion. METHODS: Determination of clonality by X chromosome inactivation pattern was investigated in twenty-one cases of neurofibroma employing enzyme digestion and PCR of the HUMARA gene. The histological, immunohistochemical, and ultrastructural characteristics of the tumors were also examined. RESULTS: Immunohistochemically, most of the tumor cells showed vimentin and S-100 protein positivity. Axons were demonstrated by neurofilament protein positivity and were seen mainly at the periphery and rarely in the central portion of the tumor. Ultrastructurally, the tumors were composed of a variety of cell types: perineurial cells, Schwann cells, fibroblasts, and axons. X chromosome inactivation analysis was completed on thirteen out of fifteen cases in which DNA was successfully extracted. Of thirteen neurofibromas that were heterozygous at the HUMARA loci, eleven showed a polyclonal pattern. The remaining two cases were considered as indeterminate for clonality because of unequal band intensity and failure to obtain the normal control DNA. CONCLUSION: The results from this study suggest that neurofibromas are polyclonal in origin and might be a neoplastic lesion comprising non-neoplastic cells among constituent components.

Study on the application of differentially methylated X-linked HUMARA in forensic medicine / 中国法医学杂志

Objective To study the Application of X-linked differentially methylated polymorphism site in forensic medicine.Methods X-STR HUMARA was chosen as a model locus.PCR procedures were performed after digestion using methylation-sensitive restriction endonucleases.STR polymorphism of HUMARA was analyzed and compared in samples collected from male and female individuals.Result After digestion with methylation-sensitive restriction enzyme HpaⅡ,no PCR products were obtained from male samples,whereas PCR products from the female samples were normally typed.In monoclonal tumor cell samples from females,only one allele was detected.Conclusion The differentially methylated X-STR HUMARA locus is a novel marker for mixture analysis of mixed stains,sex determination and discrimination of tumor tissues.

Clonality Assay of Dysplastic Epithelial Lesions of the Stomach

PURPOSE: Dysplasia or flat adenoma of the stomach is regarded as a precancerous lesion. However, the frequency and the evolutionary process of malignant transformation of gastric dysplasia are still debated. In order to see whether the lesion was a monoclonal or a polyclonal proliferation, clonality was assayed by X-linked HUMARA polymorphism. MATENRIALS AND METHODS: DNA was extracted from the paraffin-embedded tissue of 16 consecutive cases of endoscopic biopsy, eight of which supplied both dysplastic and nondysplastic tissue for comparison. HUMARA was amplified by PCR with or without pretreatment with methylation- sensitive restriction enzyme, HpaII. The amplification products were electrophoresed on polyacrylamide gel and silver-stained. RESULTS: Among the 16 cases, 13 cases were informative and 3 cases noninformative. Of the 13 cases, one case showed skewed lyonization, rendering 12 cases to be analyzed further. A monoclonal band pattern was noted in 2 cases, and a polyclonal band pattern in 10 cases. A review of the histopathologies of the monoclonal and the polyclonal cases did not reveal features discriminating the two groups. CONCLUSION: These results suggest that gastric dysplasia is a disease entity heterogeneous in the genetic level, and many cases may be non-neoplastic.

Molecular Study of X-Chromosome Mosaicism in Turner Syndrome Patients using DNAs Extracted from Archives Cytogenetic Slides

To study the X chromesome masaicism in the cytogenetically pure 45,X Turner syndrome patients, we applied PCR technique using DNAs extracted from archived cytogenetic slides. We amplified the DNAs using nested primers targeted to a highly polymorphic short tandem repeat(STR) of the human androgen receptor gene(HUMARA) for the detection of X chromosome mosaicism. This assay is a very sensitive and useful method which can be applied to the DNAs extracted from archived cytohenetic slides to detect X mosaicism. We have tested 50 normal Korean females to determine whether the HUMARA locus is highly polumorphic among Koreans. 85% of Korean population showed heterozygosity in the HUMARA locus. We analysed the 24 DNAs extracted from archived slides of patients and abortuses with Turner syndrome in cytogenetic analysis. We observed the heterozygosities of 50% from pure 45,X patients, 83% from the patients with mosaic Turner syndrome and 8.3% from the abortuses of pure 45,X. Using the PCR tecjhnique of the HUMARA locus in the archived cytogenetic slides, we detected X chtomosome mosaicsm which could not be detected in cytogenetic analysis.