Gastric cancer is the third most frequent type of neoplasia and the second most important cause o... more Gastric cancer is the third most frequent type of neoplasia and the second most important cause of death in the world. ACP01 is the first gastric adenocarcinoma cell line developed in Brazil. To evaluate chromosomal aberrations implicated in gastric carcinogenesis, we analysed three different passages (6th, 12th and 35th) of ACP01 cell line by fluorescence in situ hybridisation using chromosome 8 alpha-satellite probe. Most of the chromosome 8 alterations found involved a numerical increase of this chromosome. Chromosome 8 trisomy was detected in all cases, varying from 37% (6th passage) to 67% (35th passage), and chromosome 8 tetrasomy (also observed in all passages) varied from 2.5% (6th passage) to 30% (35th passage). The presence of five signals for chromosome 8 was observed in all passages with the highest frequency found in the 12th passage (20%). Our results confirm that trisomy of chromosome 8 is a common biological phenomenon in adenocarcinoma of stomach and can be used as a gastric mucosa malignancy marker. Although gastric tumours are frequent neoplasias, papers on their cytogenetics are scarce in the literature. It is, therefore, necessary to conduct new studies aiming to identify peculiar genetic characteristics of a tumour, which might help in diagnosis and prognosis of this disease, besides allowing more accurate therapeutic conduct to be established.
Genomic instability tends to occur at specific genomic regions known as common fragile sites (FS)... more Genomic instability tends to occur at specific genomic regions known as common fragile sites (FS). FS are evolutionarily conserved and generally involve late replicating regions with AT-rich sequences. The possible correlation between some FS and cancer-related breakpoints emphasizes on the importance of understanding the mechanisms of chromosomal instability at these sites. Although about 230 FS have already been mapped cytogenetically, only a few of them have been characterized on a molecular level. In this chapter, we provide a protocol for mapping of common FS using bacterial artificial chromosome (BAC) probes in fluorescence in situ hybridization (FISH) and suggest the usage of lymphocytes from Fanconi anemia patients as a model system. In the latter, rare FS are expressed much more frequently than in, for example, aphidicolin-induced blood lymphocyte preparations. Knowing the exact location of FS enables the molecular comparison of their location and breakpoints that appear during evolution, cancer development and inherited disorders.
Gastric cancer is the third most frequent type of neoplasia and the second most important cause o... more Gastric cancer is the third most frequent type of neoplasia and the second most important cause of death in the world. ACP01 is the first gastric adenocarcinoma cell line developed in Brazil. To evaluate chromosomal aberrations implicated in gastric carcinogenesis, we analysed three different passages (6th, 12th and 35th) of ACP01 cell line by fluorescence in situ hybridisation using chromosome 8 alpha-satellite probe. Most of the chromosome 8 alterations found involved a numerical increase of this chromosome. Chromosome 8 trisomy was detected in all cases, varying from 37% (6th passage) to 67% (35th passage), and chromosome 8 tetrasomy (also observed in all passages) varied from 2.5% (6th passage) to 30% (35th passage). The presence of five signals for chromosome 8 was observed in all passages with the highest frequency found in the 12th passage (20%). Our results confirm that trisomy of chromosome 8 is a common biological phenomenon in adenocarcinoma of stomach and can be used as a gastric mucosa malignancy marker. Although gastric tumours are frequent neoplasias, papers on their cytogenetics are scarce in the literature. It is, therefore, necessary to conduct new studies aiming to identify peculiar genetic characteristics of a tumour, which might help in diagnosis and prognosis of this disease, besides allowing more accurate therapeutic conduct to be established.
Genomic instability tends to occur at specific genomic regions known as common fragile sites (FS)... more Genomic instability tends to occur at specific genomic regions known as common fragile sites (FS). FS are evolutionarily conserved and generally involve late replicating regions with AT-rich sequences. The possible correlation between some FS and cancer-related breakpoints emphasizes on the importance of understanding the mechanisms of chromosomal instability at these sites. Although about 230 FS have already been mapped cytogenetically, only a few of them have been characterized on a molecular level. In this chapter, we provide a protocol for mapping of common FS using bacterial artificial chromosome (BAC) probes in fluorescence in situ hybridization (FISH) and suggest the usage of lymphocytes from Fanconi anemia patients as a model system. In the latter, rare FS are expressed much more frequently than in, for example, aphidicolin-induced blood lymphocyte preparations. Knowing the exact location of FS enables the molecular comparison of their location and breakpoints that appear during evolution, cancer development and inherited disorders.
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Papers by L. Quintana