Polymorphisms and haplotypes of TLR-4/9 associated with bacterial infection, gingival inflammation/recession and oral cancer

Abstract

The expression and SNPs of innate immunity genes TLR-4/9 for bacterial infection, gingival inflammation/gingival recession (GIGR), and oral squamous cell carcinoma (OSCC) are largely unknown. 235 specimens (120 OSCC cases, among which 85 cases with either Porphyromonas gingivalis, Fusobacterium nucleatum or Treponema denticola infection and GIGR) and 115 healthy controls were used to know the expression and polymorphisms (TLR-4: N1:rs10759931, N2:rs11536889, N3:rs1927911, N4:rs4986790; TLR-9: N5:rs5743836, N6:rs352140, N7:rs187084 and N8:rs352139) of TLR-4/9 by western blot, RT-PCR, and allele-specific (AS)-PCR followed by sequencing. Increased TLR-4/9 mRNA/protein expression, bacterial infection (BI) and GIGR were associated with OSCC incidence. One of the three BI and GIGR was observed in 70.83% of OSCC cases, whereas all the HC used were free from any of these three BI/GIGR. The N3: CT-genotype (Odds Ratio hereafter as O.R.=1.811, p=0.0338), TT-genotype (O.R.=3.094, p=0.0124), 'T'-allele (O.R.=1.821, p=0.003), N4: AG-genotype (O.R.=2.015, p=0.0222) and 'G'-allele (O.R.=1.86, p=0.018) of TLR-4 as well as the N5: CC-genotype (O.R.=3.939, p=0.0017), 'C'-allele (O.R.=1.839, p=0.0042), N6: AA-genotype (O.R.=2.195, p=0.0234), 'A'-allele (O.R.=1.569, p=0.0163), N7: TC-genotype (O.R.=2.083, p=0.0136), CC-genotype (O.R.=2.984, p=0.003) and 'C'-allele (O.R.=1.885, p=0.0008) of TLR-9 were associated with increased OSCC risk. Similarly, the N2:'C'-allele (O.R.=1.615, p=0.0382), N3: TT-genotype (O.R.=2.829, p=0.0336), 'T'-allele (O.R.=1.742, p=0.0115), N4: AG-genotype (O.R.=2.221, p=0.0147) and 'G'-allele (O.R.=1.890, p=0.0238) of TLR-4 as well as the N5: CC-genotype (O.R.=2.830, p=0.031), N6: AA-genotype (O.R.=2.6, p=0.0122) and 'A'-allele (O.R.=1.746, p=0.0064), N7:CC-genotype (O.R.2.706, p=0.0111) and 'C'-allele (O.R. 1.774, p=0.0055) of TLR-9 were correlated with GIGR and BI. TLR-4 (N1-N2-N3-N4: A-C-T-A (O.R.=2.1, p=0.0069) and TLR-9 (N5-N6-N7-N8: T-A-C-A (O.R.=2.019, p=0.0263); C-A-C-A (O.R.=6.0, p=0.0084); C-A-C-G (O.R.=4.957, p=0.0452) haplotypes were linked with OSCC vulnerability, while the TLR-4 (N1-N2-N3-N4: G-C-C-A (O.R.=0.5752, p=0.0131) and TLR-9 (N5-N6-N7-N8: T-G-T-A (O.R.=0.5438, p=0.0314); T-G-T-G (O.R.=0.5241, p=0.036) haplotypes offered protection. TLR-4/9 expression, polymorphisms, and BI-induced GIGR could increase OSCC risk. This may be used in pathogenesis and oral cancer prediction.