Cancer may be a disease of genes, arising from genetic damage of diverse sorts-recessive and dominant mutations, large rearrangement of DNA and gene translocation on chromosomes, all leading to distorsions of either the expression or biochemical
function of genes. The search for these genetic damage in neoplastic cells now is the most important in cancer research.
It has been found that the cancer relevant genes were located on the specific regions of chromosomes.
To determine whether epidermal growth factor receptor (EGFR), p53 and bcr genes located in chromosomes 7, 17 and 22 are altered, we examined 12 neuroepithelial tumor with Southern blot analysis (five low grade astrocytoma, two high grade
astrocytoma,
two medulloblastoma, one oligodendroglioma, one ependymoma, one choroid plexus papilloma).
The loss of heterozygosity (LOH) of EGFR gene was detected in two cases of medulloblastoma. The rearrangement of EGFR gene was detected in a case of ependymoma. The LOH of P53 gene was found in a case of choroid plexus papilloma and low grade
astrocytoma. The rearrangement of P53 gene was found in a case of oligodendroglioma. The LOH of bcr gene was observed in two cases of meduiloblastoma and low grade astrocytoma. The rearrangement of bcr gene was observed in two cases of high grade
astrocytoma.
These results suggested that tumorigenesis and tumor development in the neuroepithelial tumor may involve specific gene changes in chromosomes 7, 17 and 22.
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