Expression of mdr1/P-glycoprotein and p110 in neuroblastoma
Version of Record online: 15 JUN 2005
Copyright © 1995 John Wiley & Sons, Ltd.
The Journal of Pathology
Volume 175, Issue 1, pages 13–22, January 1995
How to Cite
Ramani, P. and Dewchand, H. (1995), Expression of mdr1/P-glycoprotein and p110 in neuroblastoma. J. Pathol., 175: 13–22. doi: 10.1002/path.1711750104
- Issue online: 15 JUN 2005
- Version of Record online: 15 JUN 2005
- Manuscript Accepted: 6 JUL 1994
- Manuscript Received: 30 MAR 1994
- Child Health Research Appeal Trust of the Institute of Child Health/Great Ormond Street Hospital for Children
- NHS Trust
- multidrug resistance;
Overexpression of the multidrug resistance gene, mdr1, and its product, P-glycoprotein (Pgp), has been associated with cross-resistance to structurally unrelated compounds in cell lines and tumours. Recently, a non-Pgp-mediated form of drug resistance has been described, due to the overexpression of p110, a transport protein. Thirty formalin-fixed, paraffin-embedded neuroblastoma samples from 21 cases were examined for overexpression of mdr1 and Pgp using newly established non-radioactive in situ hybridization and sensitive immunocytochemical techniques. Tumours were examined from patients with all the stages of disease and from primary and metastatic sites. Paired tumour samples (pre-chemotherapy and post-chemotherapy) were available from cases with stage 2 (n=1) and stage 4 disease (n=8). Immunoreactivity to p110 was also tested on all the samples. Mdr1 mRNA was expressed in 16/21 cases and in all the stages. Pgp immunoreactivity was detected in all the cases. Weak cytoplasmic immunoreactivity to p110 was seen in the ganglion cells in 12/21 cases. The expression of mdr1, Pgp, and p110 showed a statistically significant (two-sided Fisher exact test, P=0.04, 0.03, 0.04, respectively) correlation with differentiation (Beckwith and Martin grading) but there was no correlation with survival. Pgp immunoreactivity also showed a significant correlation with favourable clinical variables: age less than 1 year at diagnosis and stages 1, 2, and 4 s (two-sided Fisher exact test, P=0.01, 0.05, respectively).