Nephroblastoma overexpressed/cysteine-rich protein 61/connective tissue growth factor/nephroblastoma overexpressed gene-3 (NOV/CCN3), a selective adrenocortical cell proapoptotic factor, is down-regulated in childhood adrenocortical tumors.
BACKGROUND
Childhood adrenocortical tumors (ACTs) have a fetal adrenal phenotype and overexpress steroidogenic factor-1 (SF-1). Nephroblastoma overexpressed (NOV)/cysteine-rich protein 61/connective tissue growth factor/nephroblastoma overexpressed gene-3 mRNA is significantly down-regulated in childhood ACTs.


OBJECTIVE
The objective of the study was to measure NOV protein levels in childhood ACTs and characterize NOV expression regulation and biological function in human adrenocortical cells.


METHODS
Protein extracts from ACT and normal adrenal cortex samples, human adrenocortical carcinoma H295R, primary adrenocortical tumors and fetal adrenal cultures, tissue culture supernatants, and cell lysates from H295R cells overexpressing SF-1 in an inducible fashion were used.


METHODS
NOV protein levels were measured by enzyme-linked immunoassay and immunoblot. Transient transfection assays were used to study the activity of NOV promoter. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, caspase assays, and flow cytometry were used to assess the proapoptotic activity of NOV on cells in culture.


RESULTS
NOV mRNA and protein expression is lower in childhood ACTs than in normal adrenal cortex. No significant difference was observed between adenomas and carcinomas. SF-1 overexpression down-regulates NOV at the transcriptional level. NOV has a selective proapoptotic activity toward human adrenocortical cells. The C-terminal domain of NOV is responsible for its proapoptotic effect. NOV protein is expressed in DAX-1-positive human fetal adrenal cells.


CONCLUSIONS
NOV is a selective proapoptotic factor for human adrenocortical cells. Reduced expression of NOV in ACTs may play an important role in the process of childhood ACT tumorigenesis, accounting at least in part for the defect of apoptotic regression of the fetal adrenal that has been proposed to be responsible for tumor formation.
Doghman
Mabrouka
M
Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique Unité Mixte de Recherche 6097, Université de Nice Sophia Antipolis, 06560 Valbonne, France.
Arhatte
Malika
M
Thibout
Hélène
H
Rodrigues
Giovanna
G
De Moura
Juliana
J
Grosso
Sébastien
S
West
Alina Nico
AN
Laurent
Maryvonne
M
Mas
Jean-Christophe
JC
Bongain
André
A
Zambetti
Gerard P
GP
Figueiredo
Bonald C
BC
Auberger
Patrick
P
Martinerie
Cécile
C
Lalli
Enzo
E
D000236:Adenoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000302:Adrenal Cortex / Q000166:cytology* / Q000502:physiology; D000306:Adrenal Cortex Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis / Q000235:genetics* / Q000502:physiology*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002648:Child; D055513:Connective Tissue Growth Factor; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics / Q000502:physiology; D004789:Enzyme Activation / Q000502:physiology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics* / Q000502:physiology; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics*; D015151:Immunoblotting; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis / Q000235:genetics*; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D055514:Nephroblastoma Overexpressed Protein; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection
C526317:CCN2 protein, human; C526319:CCN3 protein, human; D018076:DNA, Complementary; D018398:Homeodomain Proteins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; C515057:NR5A1 protein, human; D055514:Nephroblastoma Overexpressed Protein; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D055513:Connective Tissue Growth Factor; D008156:Luciferases; D020169:Caspases