INVESTIGATION OF THE EXPRESSION OF HOUSEKEEPING GENES IN NON-HODGKINS-LYMPHOMA

Studies of quantitative changes in gene expression in malignant cells have often used housekeeping genes as controls against which the level of expression of a gene under study could be compared. We have now ex amined whether the expression of the most commonly used of these house keeping genes can be regarded as reliable controls for gene expression studies in non-Hodgkin's lymphoma (NHL). We have used Northern blot a nalysis to compare the levels of expression of beta-actin, alpha-tubul in, beta2-Microglobulin and glyceraldehyde-3-phosphate dehydrogenase ( GAPDH) to that of ribosomal RNA. These studies demonstrated that where as there was a reasonable correlation between the relative levels of r RNA and housekeeping gene expression in reactive hyperplastic nodes, t here were major differences in the relative levels of expression of th e housekeeping genes in both low and high grade lymphomas; only GAPDH showed any degree of consistency. These observations indicated that ho usekeeping gene expression was not a reliable control for estimating c hanges in the level of expression of other genes in NHL, and instead s uggested that 18S or 28S rRNA expression offered a more accurate metho d of RNA quantitation.