Microarray analysis of mouse gene expression in metronomic cyclophosphamide-treated rat glioma 9L xenografts implanted in scid mice

Cyclophosphamide (CPA) treatment on a six-day repeating metronomic schedule induces a dramatic, innate immune cell-dependent regression of implanted gliomas. However, little is known about the underlying mechanisms of innate immune cell mobilization and recruitment, or about the role of DNA damage and cell stress response pathways in eliciting the anti-tumor immune responses linked to tumor regression. To address these questions, we compared untreated and 6-day metronomic cyclophosphamide-treated rat 9L gliosarcoma xenografts by mouse microarray analysis to identify responsive mouse (host) cell-specific factors. Rat glioma 9L tumors were implanted sc in scid immunodeficient mice then treated with cyclophosphamide at 140 mg/kg every 6 days. Tumors were collected 6 days after the fourth cyclophosphamide treatment. Tumor RNA was then analyzed on two color Agilent mouse expression microarrays comparing cyclophosphamide-treated RNA to untreated control tumor RNA.