No abstract available.
Colorectal Neoplasms* ; Loss of Heterozygosity*

No abstract available.
Adenocarcinoma* ; Loss of Heterozygosity*

BACKGROUND/AIMS: The status of tumor suppression gene can be assessed indirectly by analyzing the loss of heterozygosity. Hepatoblastoma is a malignant liver tumor in childhood. To find the molecular carcinogenetic mechanism of hepatoblastoma, loss of heterozygosity (LOH) of p73, APC and p53 was studied. MATERIALS AND METHODS: Hepatoblastoma tissues from thirty-three cases were collected by lobectomy or tumorectomy. On H- stained sections, normal and tumor cells were microdissected separately and LOH analysis was perfomed using 8 markers: six of p73, one of APC and one of p53. RESULTS: Number of cases showing at least one LOH in six p73 markers was four out of twenty- six (15.4%): each LOH frequencies in D1S160, D1S170, D1S199, D1S228, D1S243 and D1S253 were in order of 7.7%, 0%, 9.1%, 0%, 12.5% and 0%. LOH frequency of APC was 41.7% and that of p53 was 13.3%. CONCLUSION: Low LOH frequency of p73 related markers indicates that p73 gene may not be implicated in carcinogenesis of hepatoblastoma.
Carcinogenesis ; Hepatoblastoma* ; Liver ; Loss of Heterozygosity*

No abstract available.
Genetic Loci* ; Loss of Heterozygosity* ; Stomach Neoplasms*

OBJECTIVE: Allelic losses or loss of heterozygosity (LOH) at many chromosomal loci have been found in the cells of meningiomas. The objective of this study was to evaluate LOH at several loci of different chromosomes (1p32, 17p13, 7q21, 7q31, and 22q13) in different grades of meningiomas. METHODS: Forty surgical specimens were obtained and classified as benign, atypical, and anaplastic meningiomas. After DNA extraction, ten polymorphic microsatellite markers were used to detect LOH. Medical and surgical records, as well as pathologic findings, were reviewed retrospectively. RESULTS: LOH at 1p32 was detected in 24%, 60%, and 60% in benign, atypical, and anaplastic meningiomas, respectively. Whereas LOH at 7q21 was found in only one atypical meningioma. LOH at 7q31 was found in one benign meningioma and one atypical meningioma. LOH at 17p13 was detected in 4%, 40%, and 80% in benign, atypical, and anaplastic meningiomas, respectively. LOH at 22q13 was seen in 48%, 60%, and 60% in benign, atypical, and anaplastic meningiomas, respectively. LOH results at 1p32 and 17p13 showed statistically significant differences between benign and non-benign meningiomas. CONCLUSION: LOH at 1p32 and 17p13 showed a strong correlation with tumor progression. On the other hand, LOH at 7q21 and 7q31 may not contribute to the development of the meningiomas.
DNA ; Hand ; Loss of Heterozygosity ; Meningioma ; Microsatellite Repeats ; Retrospective Studies

PURPOSE: Genomic alterations and abnormal expression of the fragile histidine triad (FHIT) gene in gastric cancer were examined to determine whether the FHIT gene is actually a frequent target for alteration during gastric carcinogenesis. MATENRIALS AND METHODS: To correlate DNA and RNA lesions of the FHIT gene with the effect on FHIT protein expression, in 40 gastric cancers, we investigated the FHIT gene for loss of heterozygisity (LOH), aberrant transcripts, and protein expression. RESULTS: Allelic loss at D3S1300 was detected in 7 of 38 (19%) informative cases. Aberrant transcripts were observed in 20 of 40 (50%) cases. Significant reduction of FHIT protein expression was observed in 22 of 40 (55%) cases. Aberrant FHIT transcription was shown to be associated with loss of FHIT protein expression. However, aberrent FHIT transcripts themselves were not associated with any clinicopathological parameters, such as age, sex, tumor site, or clinical stage. Moreover, there was no association between the presence of LOH at D3S1300 and the expression of aberrant FHIT transcripts. CONCLUSION: The high frequency of aberrant FHIT transcripts, the significant rate of LOH at D3S1300, and the altered expression of the FHIT protein indicate that alterations of the FHIT gene can play an important role in gastric carcinogenesis.
Carcinogenesis ; DNA ; Gene Expression* ; Histidine* ; Loss of Heterozygosity ; RNA ; Stomach Neoplasms*

The objectives of this study were to characterize the alterations of 3p and 9p in sporadic renal cell carcinomas (RCC) and to assess the relationship between the clinical stages or tumor size and the alteration of these chromosomes. Thirty eight archival, paraffin embedded tissue sections from 38 patients with RCC were analyzed for loss of heterozygosity (LOH) at 3p and 9p with 11 microsatellite markers. LOH was detected in 81.6% (31/38) and 37.8% (14/37) at 3p and 9p, respectively. The frequencies of LOH at VHL and FHIT locus were 75.6% and 72.2%, respectively. Twelve cases out of 38 showed LOH at both 9p21 and 3p. The loss of 3p in the samples tested was not related to clinical stages and tumor size, but that of 9p21 was significantly associated with advanced stage and larger tumor size. These results support that 3p deletion, including VHL and FHIT gene, play a critical role in the tumorigenesis of sporadic RCC, especially at early stage, and that 9p21 may contribute to the progression of sporadic RCC.
Carcinogenesis ; Carcinoma, Renal Cell* ; Humans ; Loss of Heterozygosity* ; Microsatellite Repeats ; Paraffin

PURPOSE: Deletion of chromosome 22q11 is associated with DiGeorge syndrome, velocardiofacial syndrome, and conotruncal anomaly face syndrome. This study was performed to determine the criteria of clinical phenotype as recognizable syndrome and to research the loss of heterozygosity in CATCH 22 patients and their family. METHODS: An evaluation of the clinical and genetic profiles of 30 persons of CATCH 22 syndrome or their family referred with a diagnosis of either congenital heart disease or cleft palate was undertaken. The deletions of 22q11 were analyzed using the fluorescences in situ hybridization(N25, Oncor) and short tandem-repeat polymorphic makers(STRP, D22S941). RESULTS: The dysmorphic features of CATCH 22 showed considerable overlap and intrafamilial difference was common. The familial cases of CATCH 22 were transmitted maternally as autosomal dominant. The target gene study using the STRP maker(D22S941) in these series showed good clinico-genetic correlation but some heterogeneity. CONCLUSION: Although 22q11 deletion was large in size and high variable in polymorphic markers, extensive evaluation clinically as well as genetically will be necessary for subgrouping of CATCH 22 syndrome due to good clinicogenetic correlation. Furthermore, we also suggest the development of new polymorphic markers to research the unknown characteristics of polymorphic markers in Korean patients with CATCH 22 syndrome.
Cleft Palate ; Diagnosis ; DiGeorge Syndrome ; Heart Defects, Congenital ; Humans ; Loss of Heterozygosity ; Phenotype ; Population Characteristics

PURPOSE: Younger women exhibit more aggressive pathological features of breast cancer than older women, based on previous studies. We wished to evaluate any molecular biological differences in breast cancer between younger and older women by determining the status of a microsatellite marker. METHODS: Microsatellite instability (MSI) and loss of heterozygosity (LOH) were investigated in paired tumour and normal tissue DNA from 32 younger (age less than 40 years old) and 32 older (age more than 50 years old) breast cancer patients with 12 simple repeated primer sets. RESULTS: MSI was observed at a single locus in 5 (15.6%) of the younger patients. In older patients, MSI was observed at a single locus in 5 (15.6%) and at multiple loci in 1 (3.1%) of the older patients. LOH was noted at a single locus in 7 (21.8%) and at multiple loci in 22 (68.7%) of 32 younger patients. In older patients, LOH was noted at a single locus in 9 (28.1%) and at multiple loci in 15 (46.9%). The greatest frequency of LOH was at loci UT5320 (37.5%), D8S321 (34.4%), D9S242 (31.3%), and D19S394 (31.3%) in younger patients and at loci L17686 (34.4%) and D19S394 (28.1%) in older patients. LOHs at D19S394 and L17686 were highly identified in both age groups. LOHs at D9S242 and D8S321 were significantly higher in the carcinomas of younger women (P=0.013, P=0.016, respectively). The LOH status was unrelated to clinical stage, nodal status, tumour size, histological grade or estrogen receptor (ER) status. A LOH at D8S321 was associated with tumor size (P=0.048) and a LOH at UT5320 was associated with histological grade (P=0.012) and ER status (P=0.018). CONCLUSION: These results indicate that the pattern of chromosomal alterations are not exactly the same, especially at loci D9S242 and D8S321, in the carcinomas of the two age groups and suggest that the molecular pathogenesis of the carcinomas is not similar.
Breast Neoplasms* ; Breast* ; DNA ; Estrogens ; Female ; Humans ; Loss of Heterozygosity ; Microsatellite Instability ; Microsatellite Repeats*

BACKGROUND/AIMS: The aim of this study was to determine the structural chromosomal aberrations, such as loss of heterozygosity (LOH) and microsatellite instability (MSI), at multiple tumor suppressor gene loci in gastric epithelial neoplasia categorized by the revised Vienna classification. METHODS: All tissue samples were excised by endoscopic mucosal resection. Sixty category 3 (low-grade adenoma) tissue samples and 51 category 4 samples (high-grade adenoma and intramucosal carcinoma with adenoma) were examined at the 7 sets of microsatellite loci linked to the tumor suppressor gene locus. RESULTS: For category 3 and 4 tissue samples, there were no differences in the frequencies of LOH-positive chromosomes or the extent of chromosomal loss. The Helicobacter-pylori (H. pylori)-positive rate was significantly higher in MSI-positive category 4 samples than in category 3 samples (p=0.04). The frequency of MSI positivity was significantly higher in category 4 samples than in category 3 samples (p=0.003). CONCLUSIONS: H. pylori infection is associated with genetic instability of the premalignant lesion. MSI occurs in the early stages of gastric carcinogenesis and its occurrence increases during malignant transformation. Detection of MSI in premalignant gastric lesions may be a surveillant of risk of malignant transformation.
Adenoma ; Chromosome Aberrations ; Genes, Tumor Suppressor ; Loss of Heterozygosity ; Microsatellite Instability ; Microsatellite Repeats ; Succinimides