Orthognathic surgery induces genomewide changes longitudinally in DNA methylation in saliva

Abstract

Objective Orthognathic surgery dramatically changes morphology of the maxillofacial deformity and improves the malocclusion morphologically and functionally. We investigated the influence of orthognathic surgery on genomewide DNA methylation in saliva. Methods Saliva was obtained from nine patients undergoing orthognathic surgery and two healthy reference individuals before and 3 months after orthognathic surgery. Genomewide DNA methylation profiling of saliva (341,482 CpG dinucleotides) was conducted using Infinium HumanMethylation450 BeadChips. Results Comparison between pre‐ and postsurgery saliva samples revealed significant changes in DNA methylation patterns at 2,381 CpG sites (p < 0.01) with suggestive significance. The differentially methylated probe sets were significantly associated with the cancer pathway (p = 2.8 × 10−7; a false discovery rate q‐value = 3.7 × 10−4) and PI3K‐Akt signalling pathway (p = 2.4 × 10−5; a false discovery rate q‐value = 3.1 × 10−2). Conclusion Pathway enrichment analysis of genes with suggestive significance demonstrated that altered DNA methylation in saliva of patients undergoing orthognathic surgery, possibly as a response to surgical stress or bone injury. Further studies with a large sample size and long‐term observation are needed to validate the phenomena identified in this study.

Promising applications of human-derived saliva biomarker testing in clinical diagnostics

“…It was perhaps due to the response to surgical stress or bone injury. 41 In neurodegenerative diseases, Chuang et al unveiled five significant CpGs. 42 Elaheh et al observed allele-specific methylation in CD4 + cells instead of saliva.…”

“…MALDI-TOF mass spectrometer 27 CpG sites in the promoter (MT2 region) 25 2. Infinium HumanMethylation450K array 485 000 probes 26 , 35 , 37 , 41 , 42 , 44 , 46 , 47 , 51 , 301 3. ddPCR (1) cg05575921 and DMR16( 27 , 29 , 30 2) cg14361627, cg14361627, cg08928145 and cg07547549 302 4. Illumina MethylationEPIC BeadChip 795,694 probes 33 , 54 5. methylation specific polymerase chain reaction and agarose gel electrophoresis (1) p16INK4a and p14ARF 28 (2) SOCS1 40 (3) p16, DAP- K, MGMT, and GSTP1 38 (4) ZNF282 and HPCAL1 52 6. targeted bisulfite sequencing (TBS) protocol 3.1 million CpG sites 34 7. pyrosequencing (1) LEP, ICAM-1, CRH, and LINE-1 genes 36 (2) BDNF 45 (3) NMUR2 and UBE2U 50 (4) ZC3H12D, BCAS4 and cg06379435 53 (5) FADS1 and FADS2 43 8. real-time methylation-specific polymerase chain reaction (1) P16 39 …”