Upregulation of glyceraldehyde-3-phosphate dehydrogenase mRNA in the spleen of tumor-bearing mice

The influence of tumor implantation on glyceraldehyde-3-phosphate dehydroge nase (GAPDH) mRNA levels and stability was determined in the spleen of tumo r-bearing mice. While GAPDH mRNA levels were not altered in skeletal muscle , kidney and liver from tumor-bearing mice, tumor implantation led to a 5.6 -fold increase in the levels of splenic GAPDH mRNA. An enhanced message sta bility was observed in splenocytes from tumor-bearing animals, suggesting t he involvement of post-transcriptional mechanisms in the selective GAPDH mR NA accumulation after tumor implantation. The GAPDH activity/glycolytic flu x ratio was 18.5 in the spleen of healthy mice. Therefore, the three-fold i ncrease in the glycolytic flux observed after tumor implantation could hard ly justify the necessity for the upregulation of GAPDH. (C) Society francai se de biochimie et biologie moleculaire/Editions scientifiques et medicales Elsevier SAS.