Oral tongue cancer gene expression profiling: Identification of novel potential prognosticators by oligonucleotide microarray analysis.
BACKGROUND
The present study is aimed at identifying potential candidate genes as prognostic markers in human oral tongue squamous cell carcinoma (SCC) by large scale gene expression profiling.


METHODS
The gene expression profile of patients (n=37) with oral tongue SCC were analyzed using Affymetrix HG_U95Av2 high-density oligonucleotide arrays. Patients (n=20) from which there were available tumor and matched normal mucosa were grouped into stage (early vs. late) and nodal disease (node positive vs. node negative) subgroups and genes differentially expressed in tumor vs. normal and between the subgroups were identified. Three genes, GLUT3, HSAL2, and PACE4, were selected for their potential biological significance in a larger cohort of 49 patients via quantitative real-time RT-PCR.


RESULTS
Hierarchical clustering analyses failed to show significant segregation of patients. In patients (n=20) with available tumor and matched normal mucosa, 77 genes were found to be differentially expressed (P< 0.05) in the tongue tumor samples compared to their matched normal controls. Among the 45 over-expressed genes, MMP-1 encoding interstitial collagenase showed the highest level of increase (average: 34.18 folds). Using the criterion of two-fold or greater as overexpression, 30.6%, 24.5% and 26.5% of patients showed high levels of GLUT3, HSAL2 and PACE4, respectively. Univariate analyses demonstrated that GLUT3 over-expression correlated with depth of invasion (P<0.0001), tumor size (P=0.024), pathological stage (P=0.009) and recurrence (P=0.038). HSAL2 was positively associated with depth of invasion (P=0.015) and advanced T stage (P=0.047). In survival studies, only GLUT3 showed a prognostic value with disease-free (P=0.049), relapse-free (P=0.002) and overall survival (P=0.003). PACE4 mRNA expression failed to show correlation with any of the relevant parameters.


CONCLUSIONS
The characterization of genes identified to be significant predictors of prognosis by oligonucleotide microarray and further validation by real-time RT-PCR offers a powerful strategy for identification of novel targets for prognostication and treatment of oral tongue carcinoma.
Estilo
Cherry L
CL
Dental Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, NY, USA. estiloc@mskcc.org
O-charoenrat
Pornchai
P
Talbot
Simon
S
Socci
Nicholas D
ND
Carlson
Diane L
DL
Ghossein
Ronald
R
Williams
Tijaana
T
Yonekawa
Yoshihiro
Y
Ramanathan
Yegnanarayana
Y
Boyle
Jay O
JO
Kraus
Dennis H
DH
Patel
Snehal
S
Shaha
Ashok R
AR
Wong
Richard J
RJ
Huryn
Joseph M
JM
Shah
Jatin P
JP
Singh
Bhuvanesh
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D004268:DNA-Binding Proteins; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D051274:Glucose Transporter Type 3 / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D043484:Proprotein Convertases / Q000235:genetics; D012697:Serine Endopeptidases / Q000235:genetics; D014062:Tongue Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D051274:Glucose Transporter Type 3; C104147:SALL2 protein, human; C495687:SLC2A3 protein, human; D014157:Transcription Factors; C080654:PCSK6 protein, human; D043484:Proprotein Convertases; D012697:Serine Endopeptidases