Research Paper Volume 7, Issue 10 pp 854—867
The p53 tumor suppressor protein protects against chemotherapeutic stress and apoptosis in human medulloblastoma cells
- 1 Lombardi Comprehensive Cancer Center and Department of Oncology, Georgetown University Medical Center, Washington, DC 20057, USA
- 2 Department of Radiation Oncology, University of Colorado, Denver, CO 80208, USA
- 3 Center for Cancer and Immunology Research, Children's National Medical Center, Washington, DC 20057, USA
- 4 Department of Pathology, Georgetown University Medical Center, Washington, DC 20057, USA
Received: August 30, 2015 Accepted: October 2, 2015 Published: October 27, 2015
https://doi.org/10.18632/aging.100831How to Cite
Abstract
Medulloblastoma (MB), a primitive neuroectodermal tumor, is the most common malignant childhood brain tumor and remains incurable in about a third of patients. Currently, survivors carry a significant burden of late treatment effects. The p53 tumor suppressor protein plays a crucial role in influencing cell survival in response to cellular stress and while the p53 pathway is considered a key determinant of anti-tumor responses in many tumors, its role in cell survival in MB is much less well defined. Herein, we report that the experimental drug VMY-1-103 acts through induction of a partial DNA damage-like response as well induction of non-survival autophagy. Surprisingly, the genetic or chemical silencing of p53 significantly enhanced the cytotoxic effects of both VMY and the DNA damaging drug, doxorubicin. The inhibition of p53 in the presence of VMY revealed increased late stage apoptosis, increased DNA fragmentation and increased expression of genes involved in apoptosis, including CAPN12 and TRPM8, p63, p73, BIK, EndoG, CIDEB, P27Kip1 and P21cip1. These data provide the groundwork for additional studies on VMY as a therapeutic drug and support further investigations into the intriguing possibility that targeting p53 function may be an effective means of enhancing clinical outcomes in MB.