SCCRO (DCUN1D1) induces extracellular matrix invasion by activating matrix metalloproteinase 2.
OBJECTIVE
Ectopic expression of squamous cell carcinoma-related oncogene (SCCRO or DCUN1D1) in NIH-3T3 cells induces invasion in vitro and produces highly invasive xenografts in nude mice with a propensity for regional lymphatical metastasis. The aim of this study was to identify the molecular mechanism underlying SCCRO-induced invasion and metastasis.


METHODS
The molecular mechanism of SCCRO-mediated effects on matrix metalloproteinase-2 (MMP2) levels and activity were assessed using a combination of cell biological and molecular methods, including real-time PCR, reporter assay, RNA interference, and chromatin immunoprecipitation assay. Tumor specimens from primary upper aerodigestive tract carcinomas (n = 89) were examined for levels of SCCRO, MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2 mRNA by real-time PCR.


RESULTS
Overexpression of SCCRO increases MMP2 levels and activity, which is required for SCCRO-induced invasion. Modified McKay assays reveal that SCCRO does not bind to the MMP2 promoter, suggesting that its transcriptional effects are indirect. Deletion or mutation of the activator protein-2 (AP2) and p53 binding element within the MMP2 promoter abrogates SCCRO-driven activation. Ectopic expression of SCCRO increases AP2 levels and promotes the binding of p53 to the MMP2 promoter. Consistent with these findings, SCCRO and MMP2 are coexpressed (P<0.0001; r(2)=0.58; 95% confidence interval, 0.46-0.69) in primary (upper aerodigestive tract) carcinomas (n=89), and this coexpression is associated with an increased prevalence of regional nodal metastasis (P=0.04; relative risk, 1.53).


CONCLUSIONS
SCCRO-induced invasion involves activation of MMP2 transcription in an AP2- and p53-dependent manner. SCCRO is a potential marker for metastatic progression in affected cancers.
O-charoenrat
Pornchai
P
The Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Sarkaria
Inderpal
I
Talbot
Simon G
SG
Reddy
Pabbathi
P
Dao
Su
S
Ngai
Ivan
I
Shaha
Ashok
A
Kraus
Dennis
D
Shah
Jatin
J
Rusch
Valerie
V
Ramanathan
Y
Y
Singh
Bhuvanesh
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000235:genetics*; D045744:Cell Line, Tumor; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D016158:Genes, p53; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008175:Lung Neoplasms / Q000201:enzymology / Q000235:genetics; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis*; D051379:Mice; D008875:Middle Aged; D009362:Neoplasm Metastasis; D015513:Oncogene Proteins / Q000235:genetics*; D009857:Oncogenes; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050656:Transcription Factor AP-2 / Q000502:physiology
C408631:DCUN1D1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050656:Transcription Factor AP-2; D020778:Matrix Metalloproteinase 2