Loss of heterozygosity (LOH) of MIR15A/MIR16-1, negative regulators of the anti-apoptotic gene BCL2, is not frequent in odontogenic keratocysts

Publication date: Available online 31 January 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Author(s): Taynara Asevedo Campos de Resende, Vanessa de Fátima Bernardes, Jéssica Carolina da Silva, Luiz Armando De Marco, Ricardo Santiago Gomez, Carolina Cavalieri Gomes, Marina Gonçalves Diniz
Objectives The odontogenic keratocyst (OKC) is an aggressive odontogenic cyst that shows high recurrence rate. Apart from PTCH1 mutations, few molecular alterations are described in OKCs. Low expression of microRNAs (miRNAs) miR-15a and/or miR-16-1 in association with increased expression of their target, Bcl-2, have been previously shown in OKC. In humans, MIR15A and MIR16-1 are clustered at chromosome position 13q14, and loss of heterozygosity (LOH) at this locus occurs in different tumors. We aimed to determine whether deletion at 13q14 is the potential mechanism leading to miR-15a/16-1 aberrant expression in OKC. Methods Genomic DNA was extracted from 15 formalin fixed paraffin embedded microdissected OKC cases. The polymorphic DNA markers D13S272 and D13S273 on chromosome 13q14.3, around MIR15A/MIR16-1, were amplified by PCR. LOH was examined by capillary electrophoresis DNA-fragment analysis. Results D13S272 marker showed no LOH in 12 informative cases, while 2/9 (22%) informative cases showed LOH at D13S273 marker. Conclusions LOH event at MIR15A/MIR16-1 locus is not frequent in OKC. The mechanism underlining the regulation of miR-15a and miR-16-1 expression in OKC remains to be determined.



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