Thérèse Faure

Characterization of trans-immortalized hepatic cell lines established from transgenic mice

Hepato-specific regulatory (promoter/enhancer) DNA sequences were used for targeting the expression of onc genes, such as murine c-myc and Simian Virus 40 T Antigen, to hepatocytes of transgenic mice which subsequently developed hepatocellular carcinomas after a variable period of time (depending on the type of onc gene employed). Several trans-immortalized cell lines were established and compared with respect to the expression of adult hepatic markers and response to growth factors. Despite the morphological differences observed between trans-hepatomas, owing to the expression of the two different onc genes, all tumor-derived cell lines behaved in a comparable fashion during long-term culture displaying an adult hepatic phenotype for at least 40 passages. They differed, however, in response to epidermal growth factor. When the gene coding for human alpha 1-antitrypsin was placed under the control of the same hepato-specific promoter/enhancer, high levels of the human recombinant protein could be harvested from the supernatants of trans-hepatoma-derived cell lines.

Expression of Recombinant Factor VIII Molecules in Mammalian Cells

Factor VIII (FVIII) is an essential cofactor involved in blood clotting. It functions in the intrinsic pathway of coagulation in the step where the activated form of factor IX (FIXa) activates in its turn factor X to FXa. Lack or malfunction of FVIII results in the chromosome X-linked bleeding disorder haemophilia A. In blood, FVIII circulates as a complex with von Willebrand factor (VWF) which serves as carrier molecule stabilising FVIII procoagulant activity and may target FVIII to damaged sites. At present, haemophiliacs are treated by replacement therapy with plasma derived products which pose well documented problems associated with low purity and risk of contamination by viral agents such as those causing hepatitis A, B, non-A non-B and AIDS.