Ivanov S V, Kuzmin I, Wei M H, Pack S, Geil L, Johnson B E, Stanbridge E J, Lerman M I
Intramural Research Support Program, Science Applications International Corporation Frederick, Laboratory of Immunobiology, Frederick, MD 21702, USA.
Proc Natl Acad Sci U S A. 1998 Oct 13;95(21):12596-601. doi: 10.1073/pnas.95.21.12596.
To discover genes involved in von Hippel-Lindau (VHL)-mediated carcinogenesis, we used renal cell carcinoma cell lines stably transfected with wild-type VHL-expressing transgenes. Large-scale RNA differential display technology applied to these cell lines identified several differentially expressed genes, including an alpha carbonic anhydrase gene, termed CA12. The deduced protein sequence was classified as a one-pass transmembrane CA possessing an apparently intact catalytic domain in the extracellular CA module. Reintroduced wild-type VHL strongly inhibited the overexpression of the CA12 gene in the parental renal cell carcinoma cell lines. Similar results were obtained with CA9, encoding another transmembrane CA with an intact catalytic domain. Although both domains of the VHL protein contribute to regulation of CA12 expression, the elongin binding domain alone could effectively regulate CA9 expression. We mapped CA12 and CA9 loci to chromosome bands 15q22 and 17q21.2 respectively, regions prone to amplification in some human cancers. Additional experiments are needed to define the role of CA IX and CA XII enzymes in the regulation of pH in the extracellular microenvironment and its potential impact on cancer cell growth.
为了发现参与冯·希佩尔-林道（VHL）介导的致癌作用的基因，我们使用了稳定转染了表达野生型VHL转基因的肾癌细胞系。应用于这些细胞系的大规模RNA差异显示技术鉴定出了几个差异表达的基因，包括一个α碳酸酐酶基因，命名为CA12。推导的蛋白质序列被归类为一种单次跨膜碳酸酐酶，在细胞外碳酸酐酶模块中具有明显完整的催化结构域。重新导入的野生型VHL强烈抑制了亲代肾癌细胞系中CA12基因的过表达。对于编码另一种具有完整催化结构域的跨膜碳酸酐酶的CA9，也得到了类似的结果。虽然VHL蛋白的两个结构域都参与了CA12表达的调控，但单独的elongin结合结构域就能有效地调控CA9的表达。我们将CA12和CA9基因座分别定位到染色体带15q22和17q21.2，这两个区域在某些人类癌症中容易发生扩增。需要进一步的实验来确定CA IX和CA XII酶在调节细胞外微环境pH值及其对癌细胞生长的潜在影响中的作用。
