1. Characterization and strong risk association of TLR2 del -196 to -174 polymorphism and Helicobacter pylori and their influence on mRNA expression in gastric cancer
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Juliana Garcia de Oliveira-Cucolo, Ana Paula Simedan Vila, Ana Elizabete Silva, Mariah Cristina Antunes do Nascimento, Eny Maria Goloni-Bertollo, Vilson Serafim Junior, Caroline de Matos Lourenço, Gabriela Helena Rodrigues-Flemming, Manoela Dias Susi, Univ Sagrado Coracao, Universidade de São Paulo (USP), and Universidade Estadual Paulista (Unesp)
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Mrna expression ,Chronic gastritis ,03 medical and health sciences ,0302 clinical medicine ,Gene expression ,Medicine ,biology ,Helicobacter pylori ,business.industry ,Gastroenterology ,Case Control Study ,biology.organism_classification ,medicine.disease ,TLR2 ,Toll-like receptor 2 ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,030211 gastroenterology & hepatology ,business ,Gastric cancer ,Polymorphisms - Abstract
Made available in DSpace on 2020-12-10T20:00:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-15 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) BACKGROUND Toll-like receptor-2 (TLR2) is responsible for recognizing Helicobacter pylori (H. pylori) and activating the immune response. Polymorphisms in TLR2 may modulate gastric carcinogenesis. AIM To evaluate whether the TLR2 19216T/C (rs3804099) and TLR2 -196 to -174 ins/del (rs111200466) polymorphisms contribute to gastric carcinogenesis in the Brazilian population, and to determine the influence of both polymorphisms and H. pylori infection on TLR2 mRNA expression. METHODS DNA was extracted from 854 peripheral blood leukocyte or gastric tissue samples [202 gastric cancer (GC), 269 chronic gastritis (CG), and 383 control/healthy (C)] and genotyped by allele-specific PCR or restriction fragment length polymorphism (RFLP)-PCR. Quantitative polymerase chain reaction by TaqMan(R) assay was used to quantify TLR2 mRNA levels in fresh gastric tissues (48 GC, 36 CG, and 14 C). RESULTS Regarding the TLR2 -196 to -174 polymorphism, the ins/del and del/del genotypes were associated with a higher risk of GC by comparison with the C in all of the analyzed inheritance models (codominant, dominant, recessive, overdominant and log-additive; P < 0.0001). Similarly, an increased risk was observed when comparing the GC and CG groups [codominant (P < 0.0001), dominant (P < 0.0001), recessive (P = 0.0260), overdominant (P < 0.0001) and log-additive (P < 0.0001)]. In contrast, TLR2 19216T/C was associated with a protective effect in the GC group compared to the C group [dominant (P = 0.0420) and log-additive (P = 0.0300)]. Regarding the association of polymorphisms with H. pylori infection, individuals infected with H. pylori and harboring the TLR2 -196 to -174 ins/del polymorphism had an increased risk of gastric carcinogenesis [codominant (P = 0.0120), dominant (P = 0.0051), overdominant (P = 0.0240) and log-additive (P = 0.0030)], while TLR2 19216T/C was associated with a protective effect [codominant (P = 0.0039), dominant (P < 0.0001), overdominant (P = 0.0097) and log-additive (P = 0.0021)]. TLR2 mRNA levels were significantly increased in the GC group (median RQ = 6.95) compared to the CG group (RQ = 0.84, P < 0.0001) and to the normal mucosa group (RQ = 1.0). In addition, both H. pylori infection (P < 0.0001) and the presence of the polymorphic TLR2 -196 to -174del (P = 0.0010) and TLR2 19216 C (P = 0.0004) alleles influenced TLR2 mRNA expression. CONCLUSION The TLR2 -196 to -174 ins/del and TLR2 19216 T/C polymorphisms are strongly associated with GC. TLR2 mRNA expression levels are upregulated in neoplastic tissues and influenced by both the presence of H. pylori and variant genotypes. Univ Sagrado Coracao, Dept Grad Level Res, BR-17011970 Bauru, SP, Brazil Sao Jose do Rio Preto Sch Med, Dept Mol Biol, BR-15090000 Sao Jose Do Rio Preto, SP, Brazil Sao Paulo State Univ, Dept Biol, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Sao Paulo State Univ, Dept Biol, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil FAPESP: 2013/14022-6 FAPESP: 2014/177161
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- 2020