ALTERATIONS OF THE GROWTH-CHARACTERISTICS OF THE FIBROBLAST CELL-LINEC3H 10T1 2 BY MEMBERS OF THE WNT GENE FAMILY/

Retroviral vectors were used to introduce members of the Wnt gene fami ly into the embryonic fibroblast cell line C3H 10T1/2. In contrast to previous reports where no effect of Wnt genes on fibroblasts was seen, we found that the expression of Wnt-1, Wnt-6 and Wnt-7b altered the a ppearance of the cells when maintained at confluence. The cells were s maller and grew to a higher density than cells containing a control. r etrovirus or cells expressing Wnt-4 or Wnt-5b. Detailed analysis of gr owth characteristics of polyclonally infected cultures demonstrated th at the Wnt-1, Wnt-6 and Wnt-7b expressing cells grew to a higher densi ty in 5% fetal calf serum than control or Wnt-5b expressing cells. Wnt -4 expressing cells grew to a marginally higher density than control c ells. In 0.5% serum, growth of the Wnt-1, Wnt-6 and Wnt-7b containing cells appeared to be inhibited. No growth in soft agar was observed fo r either control cells or Wnt expressing cells. We conclude that at le ast some mesenchymal cells can respond to Wnt gene products. Our resul ts are also the first report of biological effects of Wnt-6 and Wnt-7b .