Over 44,500 people in the United States are diagnosed with a primary tumor in the brain or spine each year. Ofthis group, approximately 20,500 are diagnosed with primary malignant brain tumors. Brain tumors are also thesecond most common cancer of childhood comprising approximately 25% of all pediatric cancers. It is theleading cause of solid tumor cancer death in children. Mortality rates from brain tumors are extremely high,with a median survival of approximately 12 months. Notably, mortality rates have remained unchanged overthe last two decades as malignant gliomas continue to present significant problems for successful clinicaltreatment with the current regimen of surgery, radiotherapy or chemotherapy. The highly aggressive nature ofmalignant gliomas - glioblastoma cells rapidly invade the surrounding brain parenchyma - stems from defectsin genes that control cell motility. Invasive tumor cells remaining after surgical resection confound clinicalmanagement and significantly contribute to the lethality of this disease. Additionally, a chemotherapy andradiotherapy resistant subpopulation of glioma cells retain stem cell-like properties to re-seed the tumor. Thisleads to recurrence with even poorer prognosis. The glioma stem cell population may harbor defects in genesthat control self-renewal, proliferation and differentiation. Effective targeting of these invasive cells and thestem cell population is critical for the improved management and positive clinical outcome in malignantgliomas. The objective of this proposal is to determine if apical-basal polarity signaling is an importantmolecular element in the invasive pathology and recurrence of gliomas. We have observed that altered apical-basal polarity signaling causes the rapid proliferation and abnormal migration of undifferentiated cells bearingmarkers of embryonic neural stem cells in the developing chick central nervous system. Based on this previousstudy, we hypothesize that aberrant function of apical-basal polarity signaling pathway may play a central rolein the invasive progression and growth of glioblastoma.
The specific aims of this proposal are: (i) to validateour preliminary observation of a positive association between elevated apical-basal polarity signaling pathwaycomponents and clinical glioblastoma, and to investigate the function of this pathway in glioma pathology. Thisstudy is likely to elucidate the molecular function of apical-basal polarity signaling pathway in glioma invasion,growth and progression, and provide the proof-of-concept for targeting this pathway as a novel strategy forglioblastoma therapy. Our long-term goal is the rational targeting of this pathway in an improved therapeuticparadigm for gliomas.
Prospects for better efficacy of glioma treatment protocols hinge on the successfulunraveling of molecular pathways that control the aberrant invasion and recurrence ofglioma tumors. Our experiments are designed to identity a novel molecular element thataids glioma invasion and growth; and understand the molecular basis of its function.Successful completion of this study will establish the proof-of-concept for rationaltherapeutic targeting of a novel; pharmacologically tractable; drug discovery target tospecifically counter glioma tumor spread and growth.
