TY - JOUR

T1 - Differential expression of a chloride intracellular channel gene, CLIC4, in transforming growth factor-β1-mediated conversion of fibroblasts to myofibroblasts

AU - Rønnov-Jessen, Lone

AU - Villadsen, René

AU - Edwards, John C.

AU - Petersen, Ole W.

N1 - Funding Information: Supported by the Danish Research Council, the Danish Cancer Society, the Novo Nordic Foundation, the Meyer Foundation, the Friis Foundation, Fru Astrid Thaysens Legat for Lægevidenskabelig Grundforskning (to L.R.-J., R.V. and O.W.P.), Weimanns Legat (to L.R.-J.), National Institutes of Health grant CA-64786-02 (to O.W.P.), National Institutes of Health grant 44838 , and a Merit Award from the Department of Veterans Affairs (to J.C.E.).

PY - 2002

Y1 - 2002

N2 - Conversion of fibroblasts into myofibroblasts as mediated by transforming growth factor-β1 (TGF-β1) is the most prominent stromal reaction to a number of epithelial lesions including breast cancer. To identify genes which are regulated during this process, the mRNA profiles from primary breast fibroblasts treated with or without TGF-β1 were analyzed by differential display. Ninety-five differentially expressed transcripts were PCR-cloned and sequenced, and 28 clones were selected for verification in a hybridization array. By use of gene-specific sequence tags, nine differentially expressed genes were identified. One of the clones, identified as CLIC4, a member of the CLIC family of chloride channels, was up-regulated more than 16 times in myofibroblasts and was therefore chosen for further analysis. Using RT-PCR, comparison with CLIC1, CLIC2, CLIC3, and CLIC5 demonstrated that CLIC4 was unique by being up-regulated by TGF-β1 in myofibroblasts. Immunohistochemistry showed a hitherto unknown, distinctive pattern of CLIC4 expression in breast stroma. Whereas normal breast fibroblasts were devoid of CLIC4 protein expression, myofibroblasts of breast carcinomas were strongly CLIC4-positive. The functional significance of CLIC4 was analyzed in MEF/3T3 fibroblasts by conditional expression using the tetracycline-repressive gene regulation system. In a migration assay, we found that CLIC4 inhibited cell motility by 27%. These results suggest that CLIC4 is differentially regulated in fibroblasts and that its expression contributes to a collective stationary myofibroblast phenotype.

AB - Conversion of fibroblasts into myofibroblasts as mediated by transforming growth factor-β1 (TGF-β1) is the most prominent stromal reaction to a number of epithelial lesions including breast cancer. To identify genes which are regulated during this process, the mRNA profiles from primary breast fibroblasts treated with or without TGF-β1 were analyzed by differential display. Ninety-five differentially expressed transcripts were PCR-cloned and sequenced, and 28 clones were selected for verification in a hybridization array. By use of gene-specific sequence tags, nine differentially expressed genes were identified. One of the clones, identified as CLIC4, a member of the CLIC family of chloride channels, was up-regulated more than 16 times in myofibroblasts and was therefore chosen for further analysis. Using RT-PCR, comparison with CLIC1, CLIC2, CLIC3, and CLIC5 demonstrated that CLIC4 was unique by being up-regulated by TGF-β1 in myofibroblasts. Immunohistochemistry showed a hitherto unknown, distinctive pattern of CLIC4 expression in breast stroma. Whereas normal breast fibroblasts were devoid of CLIC4 protein expression, myofibroblasts of breast carcinomas were strongly CLIC4-positive. The functional significance of CLIC4 was analyzed in MEF/3T3 fibroblasts by conditional expression using the tetracycline-repressive gene regulation system. In a migration assay, we found that CLIC4 inhibited cell motility by 27%. These results suggest that CLIC4 is differentially regulated in fibroblasts and that its expression contributes to a collective stationary myofibroblast phenotype.

UR - http://www.scopus.com/inward/record.url?scp=0036971427&partnerID=8YFLogxK

U2 - 10.1016/S0002-9440(10)64203-4

DO - 10.1016/S0002-9440(10)64203-4

M3 - Journal article

C2 - 12163372

AN - SCOPUS:0036971427

VL - 161

SP - 471

EP - 480

JO - American Journal of Pathology

JF - American Journal of Pathology

SN - 0002-9440

IS - 2

ER -