Deregulation of
miRNA expression may contribute to
tumorigenesis and other patho-physiology associated with
cancer. Using TLDA, expression of 762
miRNAs was checked in 18 pairs of gingivo buccal
cancer-adjacent control tissues. Expression of significantly deregulated
miRNAs was further validated in
cancer and examined in two types of precancer (
leukoplakia and
lichen planus) tissues by primer-specific TaqMan assays.
Biological implications of these
miRNAs were assessed bioinformatically. Expression of
hsa-miR-1293, hsa-miR-31, hsa-miR-31* and
hsa-miR-7 were significantly up-regulated and those of
hsa-miR-206,
hsa-miR-204 and
hsa-miR-133a were significantly down-regulated in all
cancer samples. Expression of only hsa-miR-31 was significantly up-regulated in
leukoplakia but none in
lichen planus samples. Analysis of expression heterogeneity divided 18
cancer samples into clusters of 13 and 5 samples and revealed that expression of 30
miRNAs (including the above-mentioned 7
miRNAs), was significantly deregulated in the cluster of 13 samples. From database mining and pathway analysis it was observed that these
miRNAs can significantly target many of the genes present in different
cancer related pathways such as "
proteoglycans in
cancer", PI3K-AKT etc. which play important roles in expression of different molecular features of
cancer. Expression of hsa-miR-31 was significantly up-regulated in both
cancer and
leukoplakia tissues and, thus, may be one of the molecular markers of
leukoplakia which may progress to gingivo-buccal
cancer.