Gene expression change in the lingual nerve and the traumatic neuromas after the injured lingual nerve.

The lingual nerves are incidentally injured in many oral and maxillofacial surgical procedures, traumatic neuroma was observed at the proximal stump of the injured lingual nerve in patients with severe lingual nerve disturbance. Various genes including genes related to nerve regeneration are expressed in the rat and mouse traumatic neuroma, as regeneration mechanism works after lingual nerve injury. Few reported have showed the expressed genes in the traumatic neuroma of the human lingual nerve. In this study, we compared the gene expression between pooled RNA sample from three traumatic neuromas removed in microneurosurgery in the lingual nerve and an RNA sample from the normal lingual nerve on the unaffected side of the removed tongue with cancer. The 2,357 genes increased more than twofold in the traumatic neuroma compared with the normal lingual nerve. Then, we analyzed the upregulated genes in DAVID and DAVID indicated that the 20 upregulated genes were associated with protein secretion to the extracellular space in the pathways. This study identified the 20 candidate genes at the nerve regeneration stage in the traumatic neuroma in the human lingual nerve. We removed the three traumatic neuromas in the microneurosurgery after the lingual nerve injury. We measured the expression of genes in Affymetrix GeneChip®, and we compared with a pooled RNA sample from three traumatic neuromas and an RNA sample from the normal lingual nerve on the unaffected side of the removed tongue with cancer. Total RNA was extracted from the traumatic neuroma removed lingual nerve and normal lingual nerve. An equal amount of RNA from 3 traumatic neuroma was pooled and used for microarray analysis.