人脑垂体瘤染色体分析

CHROMOSOMAL STUDY OF HUMAN PITUITARY ADENOMAS

为探讨垂体瘤及癌的发病机理与肿瘤演进过程中的细胞遗传学特征，对１５例人脑垂体瘤进行了染色体分析。实验结果表明染色体数目的分布从２４～２１０，２０％病例干系细胞为二倍体染色体，而８０％病例干系细胞为非二倍体染色体，其中亚二倍及超二倍体以上染色体病例分别为１３％和６７％。１０例人脑垂体瘤Ｇ显带核型分析，９０％病例具有２２号染色体减少及７号染色体增加，侵袭性垂体瘤７号染色体增加明显。６０％病例具有８、９号染色体的增加。提示人脑垂体瘤在病理形态学虽属良性肿瘤，而细胞遗传学却呈恶性表现。作者认为２２号染色体的丢失，７、８和９号染色体的增加，可使调控细胞增殖，分化基因缺失，癌基因活化，可能与该肿瘤的发病机理有关，７号染色体的明显增加可能为肿瘤演进中的表现。

Chromosome analysis was performed in 15 cases of pituitary adenomas. The chromosome numbers in examined cells ranged from 24 to 210, with 20% of diploid stemline cells and 80% of aneuploid,among which hypodiphoid reached 13%and hyperdipolid 6 7%,G-band karyotype analysis of 10 cases showed that loss or relative loss of chromosome 22 reached 90% and gain of chromosome 7 reached 90%. In hyperdipolid stemline cells, gain of chromosome 7 reached 100%. In addition, there were gains of chromosome 8 and chromosome 9 in 60% of the cases. Althongh human pituitary adenomas are histopathologically bening tumors, they are malignant cytogenetically. In our opinion that loss of chromosome 22 and gains of chromosomes 7,8 and 9 may lead to the loss of genes controlling cells proliferation and differentiation, and that activation of cancer genes is related to the occurrence of pituitary adenomas. An obvious gain of chromosome 7 gives indication of development of tumor.