Changes of serum protein profiles of gastric cancer patients in the point of immunosuppression

Abstract

Correlation between serum inhibitory factor level and change of serum protein fractions was investigated in gastric cancer patients. The sera from normal donor and cancer patients were separated by Polyacrylamide gel slab electrophoresis with a gradient from 3 to 27%. In normal and cancer sera, thirty to fifty separated bands were presented on the gel. These bands were applied to Densitometory and serum protein patterns were drawn. Serum protein patterns were separated into 12 fractions, and calculated as pattern similarity. Changes of pattern similarity from cancer sera were markedly different from those from normal sera, and reflected the tumor advancing. Protein analysis by DEAE-cellulose colum chromatography and immunoelectrophoresis showed that Fractions 2, 3, and 8 were identified as α1 acid glycoprotein, α1 antitrypsin, and ceruloplasmin respectively. These protein fractions increased in accordance with the advance of the disease, and were thought to act as immunosuppressive factors. On the other hand, Fractions 6 and 7 were identified as transferrin and complement components respectively, and were thought to act as immunostimulatory factors. When the ratios of these two groups were investigated, refferring to as immunoregulatory ratio, immunoregulatory ratio from cancer sera decreased significantly with the advances of the disease.