Association b/w gene expression profile & tumor invasion in OSCC

There are limited studies attempting to correlate the expression changes in oral squamous cell carcinoma with clinically relevant variables. We determined the gene expression profile of 16 tumor and 4 normal tissues from 16 patients by means of Affymetrix Hu133A GeneChips. The hybridized RNA was isolated from cells obtained with laser capture microdissection, then was amplified and labeled using T7 polymerase-based in vitro transcription. The expression of 53 genes was found to differ significantly (33 upregulated, 20 downregulated) in normal versus tumor tissues under two independent statistical methods. The expression changes in four selected genes (LGALS1, MMP1, LAGY, and KRT4) were confirmed with reverse transcriptase polymerase chain reaction. Two-dimensional hierarchical clustering of the 53 genes resulted in the samples clustering according to the extent of tumor infiltration: normal epithelial tissue, tumors less than or equal to 4 cm in dimension, and tumors more than 4 cm in dimension (P=0.0014). The same pattern of clustering was also observed for the 20 downregulated genes. We did not observe any associations with lymph node metastasis (P=0.097). Keywords: TNM,Tumor-node-metastasis LCM,Laser capture microdissection OSCC,Oral squamous cell Carcinoma We performed microarray analysis using RNA from OSCC cells obtained with LCM from 16 patients and compared these results with 4 control squamous cell epithelium samples.We identified expression profiles of differentially expressed genes between normal and tumor tissues and found that tumor invasiveness of a tumor is highly correlated with its gene expression profile.