Identification of cDNAs for Sox-4, an HMG-Box protein, and a novel human homolog of yeast splicing factor SSF-1 differentially regulated during apoptosis induced by prostaglandin A(2)/Delta(12)-PGJ(2) in Hep3B cells

We have examined specific genes whose expression is altered during apoptosi s induced by prostaglandin (PG)A(2) and Delta(12)-PGJ(2) in human hepatocel lular carcinoma Hep3B cells. Using mRNA differential display, we have ident ified two genes: one is specifically upregulated and encodes for human Sox- 4 (Sry-HMG box gene) and the other is significantly down-regulated and is t he human homolog of yeast Ssf-1, a novel splicing factor. Northern blot ana lysis-confirmed their differential expressions. Interestingly, Sox-4 was hi ghly expressed in subcutaneous tumors grown in nude mice as a xenograft fro m Hep3B cells. These results suggest that the expression of Sox-4 may be re lated to the apoptosis pathway leading to cell death as well as to tumorige nesis, and that Ssf-1 gene may serve as a negative regulator of PGA(2)/Delt a(12)-PGJ(2)-mediated Hep3B cell apoptosis. (C) 1999 Academic Press.