Hyaluronic Acid Mediated Enrichment of CD44 Expressing Glioblastoma Stem Cells in U251MG Xenograft Mouse Model

Abstract

Background: Glioblastoma is one of the most aggressive cancer with high mortality rates and poses several hurdles in the efficient chemotherapeutic intervention. Similar to other cancers, glioma also harbors CSCs, that are self-renewable, multipotent cells, which initiate the cancer incidence, chemotherapeutic resistance and cancer recurrence. The microenvironmental regulation in the brain tumor and metastasis involves the cooperative interaction between HA and CD44. CD44, being a multifaceted transmembrane glycoprotein by itself, or in combination with several other cell surface receptors, has been used as a marker for CSC isolation. Methods: We established both adherent and nonadherent culture of U251MG cells by treating with high molecular weight HA. Further these cells were transplanted subcutaneously in Balb/c mouse for the generation of the xenograft model for the cancer stem cell. The tumor was further characterized for the establishment of the working model for molecular targeting studies of cancer stem cells. Results: Here we showed the enrichment of the CD44 expressing population of glioblastoma cells by induction with hyaluronic acid. The non-adherent culture spheroids of U251MG cells showed up regulation in the CD44 expression along with aberrant activation of principal pluripotency genes OCT3/4, SOX2, KLF4 and Nanog. Using the HA-treated spheroid, we established an experimental xenograft mouse model with high angiogenesis enhanced tumor-initiating capacity while retaining the glioblastoma traits. Conclusion: We characterized a mouse xenograft model of U251MG cells which could be a promising model system to study the molecular targeting approaches against CSCs in glioblastoma.