Identifying altered gene expression in neuroblastoma cells preceding apoptosis.
OBJECTIVE
Concomitant differentiation and partial inhibition of proteasome trigger cell death in a neuroblastoma cell line (NBP2). Neither induction of differentiation nor partial inhibition of proteasome alone affects the viability of NBP2 cells. We wanted to identify genes whose expression alters under concomitant conditions and may account for cell death.


METHODS
We used gel electrophoresis to analyze total genomic DNA for the detection of DNA fragmentation. Affymetrix Murine Genome U74A version 2 microarray was used to screen for approximately 6,000 functionally characterized genes and approximately 6,000 expressed sequence tags (ESTs). Real time PCR (RT-PCR) was performed to provide an accurate assessment of changes in gene expression.


RESULTS
Concomitant differentiation and partial inhibition of proteasome trigger apoptosis, characterized by genomic DNA fragmentation in NBP2 cells. We found that the expression of 41 genes changed 2.5-fold or more primarily under concomitant conditions midway through apoptosis. Based on real time PCR, the expression of galectin-3, glycosylated 96, a leucine zipper protein (LRG-21), and endothelial cell activated protein C receptor (EPCR) increased between 50-500-fold, whereas the expression of Polo serine/threonine kinase, N-myc, and Histone H2A.1 decreased ranging from 8 to 37 fold. Altered expression of galectin-3, EPCR, and LRG-21 was detected as early as 2-8 h post simultaneous conditions.


CONCLUSIONS
We identified new genes that might be involved in apoptotic events in neuroblastoma cells.
Nahreini
Piruz
P
Department of Gastroenterology and Hepatology, School of Medicine, University of Colorado Health Sciences Center (UCHSC), Denver Health Medical Center (DHMC), Unit 7, Room 208, 777 Bannock St., Box-4000, Denver, CO 80204, USA. piruz.nahreini@uchsc.edu
Yan
Xiang-Dong
XD
Andreatta
Cynthia P
CP
Prasad
Kedar N
KN
Toribara
Neil W
NW
D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D053938:DNA Fragmentation; D020224:Expressed Sequence Tags; D015870:Gene Expression; D020869:Gene Expression Profiling; D009447:Neuroblastoma / Q000235:genetics* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors