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*

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

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: 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

Loss of heterozygosity (LOH) has been established as an important genetic mechanism giving rise to malignant neoplasia. The mechanism of LOH has been shown to cause basal cell carcinoma and malignant melanoma as well as other types of skin cancer. A few studies on LOH in sporadic keratoacanthomas have been reported. The purpose of this study was to investigate the significance of LOH in the pathogenesis of sporadic keratoacanthomas developed in 10 Korean patients. The presents of LOH at 7 microsatellite markers (D2S286, D3S1317, D5S346, D9S160, D9S171, D10S185, and D17S261) were evaluated in sporadic keratoacanthomas. LOH was found in only 1 of 10 cases at D10S185. The low frequency of LOH detected in this study suggests that LOH may not be significant in the induction of sporadic keratoacanthomas.
Adult ; Aged ; Female ; Humans ; Keratoacanthoma/*genetics ; *Loss of Heterozygosity ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't

A rare case of multiple mixed endocrine-exocrine carcinoma (MEEC) of gallbladder in a 68-year-old man is described. The lesions were two separate nodules (17x13x7 mm and 17 mm in length) on the mucosa, which were composed of predominant neuroendocrine carcinoma (NEC) infiltrating into the adventitia and minor portion of adenocarcinoma (AC) or high grade dysplasia (HGD) on the surface. Surrounding mucosa showed areas of low grade dysplasia (LGD). Two nodal metastases out of 16 nodes were found containing NEC component. By immunohistochemistry, human mutL homolog 1 (hMLH1), p53, human mutS homolog 2 (hMSH2) and human mutS homolog 6 (hMSH6) showed diffuse strong positive reaction in HGD, AC and NEC, contrasting with weak positive reaction in LGD. On genetic analysis, all lesions of HGD, AC, and NEC except for LGD showed positive loss of heterozygosity in D5S346 locus. For microsatellite instability and K-ras mutation tests, all lesions showed negative results. Common immunophenotypes and molecular results among HGD, AC, and NEC suggested that NEC of this MEEC was derived from the dysplasia-AC sequence.
Adenocarcinoma ; Adventitia ; Aged ; Carcinoma, Neuroendocrine ; Gallbladder ; Humans ; Immunohistochemistry ; Loss of Heterozygosity ; Microsatellite Instability ; Mucous Membrane ; Neoplasm Metastasis