Purpose::The pathogenesis of gastrinomas is largely unknown,and there is a lack of reliable genetic determinants that are useful to distinguish malignant and benign forms of this tumor or predict the prognosis of pati...Purpose::The pathogenesis of gastrinomas is largely unknown,and there is a lack of reliable genetic determinants that are useful to distinguish malignant and benign forms of this tumor or predict the prognosis of patients with this disease.Loss of heterozygosity(LOH)on chromosome 3p is reported to occur in pancreatic neuroendocrine tumors(PNETs)as well as in non-PNETs and its presence is reported to correlate with tumor prognosis in non-endocrine tumors.However,little data are available from prospective studies on gastrinomas.Experimental design::We assessed occurrence of 3p LOH in 24 gastrinomas and correlated its presence with tumor biological behavior and other clinicopathological features of gastrinomas.Results::Either 3p LOH or microsatellite instability involving 3p occurred in 11 of 24 tumors(46%).Seven(29%)gastrinomas had 3p LOH.Of the 7 gastrinomas with 3p LOH,5(71%)had 3p12 LOH with the marker D3S2406,which was the shortest region of highest overlap(SRO).Chromosome 3p LOH was not associated with aggressive biological behavior of gastrinomas or with poor prognosis of patients with gastrinoma.Similarly,3p12 LOH(SRO)was not correlated with aggressive growth of tumors and/or liver metastases.Conclusion::Gastrinomas have a relative high frequency of 3p12 LOH suggesting this area may harbor putative tumor suppressor gene(s),which may play a role in the tumorigenesis,but not aggressiveness,of a subset of these tumors.展开更多
Objective To identify novel tumor suppressor genes at chromosome 3p24-26 in human nasopharyngeal carcinoma (NPC).Methods Twenty epithelial-derived expressed sequence tags (EST) were selected from chromosome 3p24-26. R...Objective To identify novel tumor suppressor genes at chromosome 3p24-26 in human nasopharyngeal carcinoma (NPC).Methods Twenty epithelial-derived expressed sequence tags (EST) were selected from chromosome 3p24-26. RT-PCR and Northern blot were used to detect the expression of the ESTs in NPC cell line, HNE-1, and primary cultures of normal nasopharyngeal epithelial cells. One EST, which was substantially downregulated in the HNE-1 cell line, was detected in 19 NPC biopsy samples, cDNA library screening was used to get its full sequence and the sequence of this novel gene was analyzed.Results A novel gene located at chromosome 3p25.3 was obtained and named NAG-7. It was downregulated in 26.3％ (5/19) of NPC biopsy samples. Its 1677 bp full length cDNA had a potential open reading frame predicting a 94 amino acid protein with a molecular weight of 11023.87 Dalton. Analysis of the NAG-7 gene showed that it was a transmembrane protein containing a protein kinase C phosphorylation site and a myristyl site. It has no significant homology to any reported genes in the database of GenBank. Conclusion NAG-7 is a novel gene downregulated in NPC, suggesting that it may be involved in the development of NPC.展开更多
文摘Purpose::The pathogenesis of gastrinomas is largely unknown,and there is a lack of reliable genetic determinants that are useful to distinguish malignant and benign forms of this tumor or predict the prognosis of patients with this disease.Loss of heterozygosity(LOH)on chromosome 3p is reported to occur in pancreatic neuroendocrine tumors(PNETs)as well as in non-PNETs and its presence is reported to correlate with tumor prognosis in non-endocrine tumors.However,little data are available from prospective studies on gastrinomas.Experimental design::We assessed occurrence of 3p LOH in 24 gastrinomas and correlated its presence with tumor biological behavior and other clinicopathological features of gastrinomas.Results::Either 3p LOH or microsatellite instability involving 3p occurred in 11 of 24 tumors(46%).Seven(29%)gastrinomas had 3p LOH.Of the 7 gastrinomas with 3p LOH,5(71%)had 3p12 LOH with the marker D3S2406,which was the shortest region of highest overlap(SRO).Chromosome 3p LOH was not associated with aggressive biological behavior of gastrinomas or with poor prognosis of patients with gastrinoma.Similarly,3p12 LOH(SRO)was not correlated with aggressive growth of tumors and/or liver metastases.Conclusion::Gastrinomas have a relative high frequency of 3p12 LOH suggesting this area may harbor putative tumor suppressor gene(s),which may play a role in the tumorigenesis,but not aggressiveness,of a subset of these tumors.
文摘Objective To identify novel tumor suppressor genes at chromosome 3p24-26 in human nasopharyngeal carcinoma (NPC).Methods Twenty epithelial-derived expressed sequence tags (EST) were selected from chromosome 3p24-26. RT-PCR and Northern blot were used to detect the expression of the ESTs in NPC cell line, HNE-1, and primary cultures of normal nasopharyngeal epithelial cells. One EST, which was substantially downregulated in the HNE-1 cell line, was detected in 19 NPC biopsy samples, cDNA library screening was used to get its full sequence and the sequence of this novel gene was analyzed.Results A novel gene located at chromosome 3p25.3 was obtained and named NAG-7. It was downregulated in 26.3％ (5/19) of NPC biopsy samples. Its 1677 bp full length cDNA had a potential open reading frame predicting a 94 amino acid protein with a molecular weight of 11023.87 Dalton. Analysis of the NAG-7 gene showed that it was a transmembrane protein containing a protein kinase C phosphorylation site and a myristyl site. It has no significant homology to any reported genes in the database of GenBank. Conclusion NAG-7 is a novel gene downregulated in NPC, suggesting that it may be involved in the development of NPC.
