Human endogenous retrovirus np9 gene is over expressed in chronic lymphocytic leukemia patients

Abstract

The human genome contains a large number of endogenous retroviruses (HERVs). Their reactivation has frequently been observed in patients with cancer. Considering their role in the carcinogenesis process, we aimed to study the possible relationship between HERVs gene expression and Chronic Lymphocytic Leukemia (CLL). We focused on two viral genes gag and np9, the latter presumably an oncogene. We found that the transcriptional activity of HERV-K np9 gene was greater in CLL patients than in healthy donors. However, gag expression was not significantly increased. These findings suggest a noteworthy relationship between CLL disease and HERV-K np9 expression.

Keywords: CLL; HERVs; np9.

Fig. 1

np9 and gag mRNA relative expression levels in CLL patients with mutated and unmutated profile in their immunoglobulin Vh genes. (A) Relative expression of HERV-K np9 gene with respect to healthy donors. The dotted line represents the maximum value of np9 expression from healthy donors as a negative calibrator. (B) Relative expression of HERV-K gag gene with respect to healthy donors. The dotted line represents the maximum value of gag expression from healthy donors as a negative calibrator. The vertical error bars represent the maximum value of each CLL patient׳s sample measured by duplicated.

Fig. 2

Relative c-myc gene expression normalized to GAPDH expression in CLL patients with high and low np9 expression levels. The horizontal bars represent the median and the error bars the interquartile range. There is no significant differences (p=0.19) in the expression of c-myc gene between the analyzed groups.