The current study was undertaken with a view to identify differential
biomarkers in chewing-tobacco-associated
oral cancer tissues in patients of Indian ethnicity. The gene expression profile was analyzed in
oral cancer tissues as compared to clinically normal oral buccal mucosa. We examined 30
oral cancer tissues and 27 normal oral tissues with 16 paired samples from contralateral site of the patient and 14 unpaired samples from different
oral cancer patients, for whole genome expression using high-throughput IlluminaSentrix Human Ref-8 v2 Expression BeadChip array. The
cDNA microarray analysis identified 425 differentially expressed genes with >1.5-fold expression in the
oral cancer tissues as compared to normal tissues in the
oral cancer patients. Overexpression of 255 genes and downregulation of 170 genes (p < 0.01) were observed. Further, a minimum twofold overexpression was observed in 32 genes and downregulation in 12 genes, in 30-83% of
oral cancer patients.
Biological pathway analysis using Kyoto Encyclopedia of Genes and Genome Pathway database revealed that the differentially regulated genes were associated with critical
biological functions. The
biological functions and representative deregulated genes include cell proliferation (AIM2, FAP, TNFSF13B, TMPRSS11A); signal transduction (FOLR2,
MME, HTR3B); invasion and
metastasis (SPP1, TNFAIP6, EPHB6); differentiation (CLEC4A, ELF5); angiogenesis (CXCL1); apoptosis (GLIPR1, WISP1, DAPL1); and immune responses (CD300A, IFIT2, TREM2); and metabolism (
NNMT; ALDH3A1). Besides, several of the genes have been differentially expressed in human
cancers including
oral cancer. Our data indicated differentially expressed genes in
oral cancer tissues and may identify prognostic and therapeutic
biomarkers in
oral cancers, postvalidation in larger numbers and varied population samples.