Expression of signaling molecules in ameloblastoma using cDNA microarray: A systematic review

Aim: Ameloblastoma is a benign but locally aggressive epithelial odontogenic tumor. The present review aimed to identify the most commonly expressed signaling molecule in ameloblastoma detected using cDNA microarray. Materials and Methods: It is a systematic review. In this review, articles were searched using databases—PubMed and Google Scholar and were also searched using Hand Search. All the studies which used cDNA microarray to detect the expression of signaling molecules were included. All the variants of ameloblastoma were included for the review. A total of 22 ameloblastoma cases were included in this systematic review. Out of three studies, 67% of the cases demonstrated upregulation of smoothened (SMO) and sonic hedgehog (SHH). Results: Out of three studies, 33% of the cases showed upregulation of toll-like receptor 2 (TLR2), fos proto-oncogene (FOS), Wnt family member 10a (Wnt10a), and patched and down-regulation of insulin-like growth factor 2 (IGF2). Of the 67% of the studies which described SMO and SHH, significant expression of SMO (73 times fold change) was noted. SHH expression was noted to have 0.88 times fold change. Of the 33% of the studies included, the highest average fold change was noted to be associated with FOS (14-fold change time) followed by Wnt10a (5.1-fold change times) and TLR2 (3.29-fold change times). However, downregulation of IGF2 by 0.09-fold change times was observed in 33% of the studies. Conclusion: The SMO gene from the SHH pathway was the highest expressed signaling molecule in ameloblastoma.