Analysis of prolactin-modulated gene expression profiles during the Nb2 cell cycle using differential screening techniques.
BACKGROUND
Rat Nb2-11C lymphoma cells are dependent on prolactin for proliferation and are widely used to study prolactin signaling pathways. To investigate the role of this hormone in the transcriptional mechanisms that underlie prolactin-stimulated mitogenesis, five different techniques were used to isolate differentially expressed transcripts: mRNA differential display, representational difference analysis (RDA), subtractive suppressive hybridization (SSH), analysis of weakly expressed candidate genes, and differential screening of an organized library.


RESULTS
About 70 transcripts were found to be modulated in Nb2 cells following prolactin treatment. Of these, approximately 20 represent unknown genes. All cDNAs were characterized by northern blot analysis and categorized on the basis of their expression profiles and the functions of the known genes. We compared our data with other cell-cycle-regulated transcripts and found several new potential signaling molecules that may be involved in Nb2 cell growth. In addition, abnormalities in the expression patterns of several transcripts were detected in Nb2 cells, including the constitutive expression of the immediate-early gene EGR-1. Finally, we compared the differential screening techniques in terms of sensitivity, efficiency and occurrence of false positives.


CONCLUSIONS
Using these techniques to determine which genes are differentially expressed in Nb2 lymphoma cells, we have obtained valuable insight into the potential functions of some of these genes in the cell cycle. Although this information is preliminary, comparison with other eukaryotic models of cell-cycle progression enables identification of expression abnormalities and proteins potentially involved in signal transduction, which could indicate new directions for research.
Bole-Feysot
C
C
INSERM Unité 344, Endocrinologie Moléculaire, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
Perret
E
E
Roustan
P
P
Bouchard
B
B
Kelly
P A
PA
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics*; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D003001:Cloning, Molecular; D005057:Eukaryotic Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D008322:Mammals / Q000235:genetics; D009363:Neoplasm Proteins / Q000145:classification / Q000235:genetics; D011388:Prolactin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D014407:Tumor Cells, Cultured
D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011388:Prolactin