Hematopoietic- and Neurologic-Expressed Sequence 1 Expression in the Murine GL261 and High-Grade Human Gliomas

The hematopoietic- and neurologic-expressed sequence 1 (Hn1) gene encodes a highly conserved protein that is expressed in developing and regenerating tissues. In this study, Hn1 expression was evaluated in human and murine malignant gliomas. Hn1 mRNA and protein were detected in the murine GL261 glioma cell line and in GL261 brain tumors in vivo. HN1 is also expressed in human U118MG and U87MG cell lines. Evaluation of human brain tumors using an anti-Hn1 polyclonal antibody detected strong immunoreactivity in high-grade (WHO III and IV) malignant gliomas. The rate of GL261 cell proliferation in vitro was unaltered by Hn1 depletion using an anti-Hn1 siRNA. However, tumors established from Hn1-depleted GL261 cells formed significantly smaller volumes than those established from control-treated cells. These data suggest a role for Hn1 in the biology of malignant brain tumors.