Focal adhesion kinase expression in human neuroblastoma: immunohistochemical and real-time PCR analyses.
OBJECTIVE
The focal adhesion kinase (FAK) is a nonreceptor protein tyrosine kinase important in signaling between cells and their extracellular matrix. Studies have shown that FAK expression is up-regulated in several human tumors and is related to tumor progression. We recently found an increase in p125(FAK) expression in human neuroblastoma cells lines and wished to determine its expression in human neuroblastoma specimens and evaluate for a possible correlation between p125(FAK) expression and known prognostic factors for neuroblastoma. We hypothesized that p125(FAK) expression would be up-regulated in advanced human neuroblastomas.


METHODS
Using immunohistochemical techniques with monoclonal antibody 4.47 specific for p125(FAK) expression, we analyzed 70 formalin-fixed, paraffin-embedded human neuroblastoma specimens for p125(FAK) staining. In addition, real-time PCR was used to determine the abundance of FAK mRNA in 17 matched human neuroblastoma mRNA specimens.


RESULTS
FAK staining was present in 51 of the 70 tumor specimens (73%). Immunohistochemical staining of p125(FAK) in the ganglion-type tumor cells correlated with advanced International Neuroblastoma Staging System tumor stages and FAK mRNA abundance. In addition, p125(FAK) staining was significantly increased in stage IV tumors with amplification of the N-MYC oncogene.


CONCLUSIONS
These novel findings provide evidence that FAK is expressed by advanced-stage neuroblastoma and provide a rationale for targeting FAK in the treatment of this tumor.
Beierle
Elizabeth A
EA
Department of Surgery, University of Florida, College of Medicine, PO Box 100286, J. Hillis Miller Health Science Center, Gainesville, FL 32610-0286, USA. beierea@surgery.ufl.edu
Massoll
Nicole A
NA
Hartwich
Joseph
J
Kurenova
Elena V
EV
Golubovskaya
Vita M
VM
Cance
William G
WG
McGrady
Patrick
P
London
Wendy B
WB
D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000096:biosynthesis*; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D008297:Male; D009447:Neuroblastoma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D051417:Focal Adhesion Kinase 1