Sign up for Table of Contents Alerts.
Email this page
Print this page
Research Paper
Shift in AP-2α Localization Characterizes Astrocytoma Progression
Ramona Britto, S. Umesh, A. Hegde, Sridevi Hegde, Vani Santosh, B. Chandramouli and Kumar Somasundaram
volume 6 | issue 3
March 2007Pages: 413 - 418
We now provide open access to journal articles published online for one year or more. This article may be downloaded at the following link:
Download PDFIf the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.
Activator protein 2α (AP-2α) has been shown to be lost in the advanced stages of many cancers, including gliomas. In this study, we wanted to analyze the expression of AP-2α in astrocytoma samples of different grades both at the RNA level, by real-time qPCR and at the protein level, by immunohistochemistry, and to examine its correlation, if any, with patient outcome. Five Grade I, 14 Grade II, 18 Grade III, 72 Grade IV samples and 13 normal brain controls were included. We did not find any clear pattern of regulation at the RNA level with tumor grade. The RNA expression levels however, correlated to a large extent with the nuclear AP-2α staining in these samples (72.09%; 31/43). Further, we did not find a complete loss of nuclear AP-2α expression in the higher grades, in contrast to previous reports. Interestingly, we found cytoplasmic AP-2α expression in a majority of higher grade astrocytomas (Grade IV - 85%; 33/39 and Grade III- 74%; 14/19) in comparison to lower grades (Grade I - 0%; 0/5 and Grade II - 37.5%; 3/8) suggesting that the translocation of this protein from the nucleus to the cytoplasm may be responsible for the increased malignancy. The nuclear expression in these grades was found to be concomitantly reduced. Within GBMs, we found that decreased nuclear expression was indicative of a better prognosis. The striking observation was the shift in localization of this protein from the nucleus to the cytoplasm with increasing tumor grade, pointing to a crucial role for this transcription factor in the progression of astrocytomas.
Authors
Ramona Britto
Indian Institute of Science; Bangalore, Karnataka, India
S. Umesh
National Institute of Mental Health and Neuro Sciences; Bangalore, Karnataka, India
A. Hegde
Satya Sai Institute of Higher Medical Sciences; Bangalore, Karnataka, India
Sridevi Hegde
Manipal Hospital; Bangalore. Karnataka, India
Vani Santosh
National Institute of Mental Health and Neuro Sciences; Bangalore, Karnataka, India
B. Chandramouli
National Institute of Mental Health and Neuro Sciences; Bangalore, Karnataka, India
Kumar Somasundaram
Indian Institute of Science; Bangalore, Karnataka, India
We now provide open access to journal articles published online for one year or more. This article may be downloaded at the following link:
Download PDFIf the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.