Down-regulation of transmembrane carbonic anhydrases in renal cell carcinoma cell lines by wild-type von Hippel-Lindau transgenes

Down-regulation of transmembrane carbonic anhydrases in renal cell carcinoma cell lines by wild-type von Hippel-Lindau transgenes

^*Intramural Research Support Program, Science Applications International Corporation Frederick, Laboratory of Immunobiology, and ^‖Laboratory of Immunobiology, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, MD 21702; ^‡Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20889; ^§Medicine Branch at the Navy, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and ^¶Department of Microbiology and Molecular Genetics, University of California, College of Medicine, Irvine, CA 92717

Edited by William S. Sly, St. Louis University School of Medicine, St. Louis, MO, and approved August 12, 1998 (received for review June 12, 1998)

Abstract

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.

gene targets/differential display/carcinogenesis

Footnotes

↵ † To whom reprint requests should be addressed. e-mail: ivanov{at}ncifcrf.gov.
This paper was submitted directly (Track II) to the Proceedings Office.
Data deposition: The CA12 cDNA sequence reported in this paper has been deposited in the GenBank database (accession no. AF037335).
ABBREVIATIONS:

CA,

carbonic anhydrase (CA genes are denoted by Arabic numerals and the corresponding isozymes by Roman numerals);

EST,

expressed sequence tag;

mut,

mutant;

RCC,

renal cell carcinoma;

RDD,

RNA differential display;

VHL,

von Hippel-Lindau;

wt,

wild type