AIM To examine the effect of Fusobacterium nucleatum(F. nucleatum) on the microenvironment of colonic neoplasms and the expression of inflammatory mediators and microRNAs(miRNAs).METHODS Levels of F. nucleatum DNA, cy...AIM To examine the effect of Fusobacterium nucleatum(F. nucleatum) on the microenvironment of colonic neoplasms and the expression of inflammatory mediators and microRNAs(miRNAs).METHODS Levels of F. nucleatum DNA, cytokine gene mRNA(TLR2, TLR4, NFKB1, TNF, IL1 B, IL6 and IL8), and potentially interacting miRNAs(miR-21-3p, miR-22-3p, mi R-28-5p, miR-34a-5p, miR-135b-5p) were measured by quantitative polymerase chain reaction(qPCR) TaqMan? assays in DNA and/or RNA extracted from the disease and adjacent normal fresh tissues of 27 colorectal adenoma(CRA) and 43 colorectal cancer(CRC) patients. KRAS mutations were detected by direct sequencing and microsatellite instability(MSI) status by multiplex PCR. Cytoscape v3.1.1 was used to construct the postulated miRNA:mRNA interaction network.RESULTS Overabundance of F. nucleatum in neoplastic tissue compared to matched normal tissue was detected in CRA(51.8%) and more markedly in CRC(72.1%). We observed significantly greater expression of TLR4, IL1 B, IL8, and miR-135 b in CRA lesions and TLR2, IL1 B, IL6, IL8, mi R-34 a and miR-135 b in CRC tumours compared to their respective normal tissues. Only two transcripts for miR-22 and miR-28 were exclusively downregulated in CRC tumour samples. The mRNA expression of IL1 B, IL6, IL8 and miR-22 was positively correlated with F. nucleatum quantification in CRC tumours. The mRNA expression of miR-135 b and TNF was inversely correlated. The miRNA:mRNA interaction network suggested that the upregulation of miR-34 a in CRC proceeds via a TLR2/TLR4-dependent response to F. nucleatum. Finally, KRAS mutations were more frequently observed in CRC samples infected with F. nucleatum and were associated with greater expression of miR-21 in CRA, while IL8 was upregulated in MSI-high CRC.CONCLUSION Our findings indicate that F. nucleatum is a risk factor for CRC by increasing the expression of inflammatory mediators through a possible mi RNA-mediated activation of TLR2/TLR4.展开更多
AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor(TLR)2-196 to-174 del and TLR4-1607T/C(rs10759932) on m RNA and protein expression in tumor tissue and of TLR4+896A/G(rs4986790) on col...AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor(TLR)2-196 to-174 del and TLR4-1607T/C(rs10759932) on m RNA and protein expression in tumor tissue and of TLR4+896A/G(rs4986790) on colorectal cancer(CRC) risk.METHODS: The TLR2-196 to-174 del polymorphism was investigated using allele-specific polymerase chain reaction(PCR) and the TLR4-1607T/C and TLR4+896A/G by PCR-restriction fragment length p o l y m o r p h i s m( R F L P). W e g e n o t y p e d 4 3 4 D N A samples from 194 CRC patients and 240 healthy individuals. The m RNA relative quantification(RQ) was performed in 40 tumor tissue samples by quantitative PCR Taq Man assay, using specific probes for TLR2 and TLR4 genes, and ACTB and GAPDH reference geneswere used as endogenous controls. Protein expression was analyzed by immunohistochemistry with specific primary antibodies.RESULTS: No association was found for TLR4-1607T/C and TLR4+896A/G by three statistical models(logadditive, dominant and recessive). However, based on dominant and log-additive models, the polymorphic variant TLR2-196 to-174 del was associated with increased CRC risk [dominant: odds ratio(OR) = 1.72, 95%CI: 1.03-2.89; P = 0.038 and log-additive: OR =1.59, 95%CI: 1.02-2.48; P = 0.039]. TLR2 m RNA expression was increased in tumor tissue(RQ = 2.36) when compared to adjacent normal tissue(RQ = 1; P < 0.0001), whereas the TLR4 m RNA showed a basal expression(RQ = 0.74 vs RQ = 1, P = 0.452). Immunohistochemistry analysis of TLR2 and TLR4 protein expression was concordant with the findings of m RNA expression. In addition, the TLR2-196 to-174 del variant carriers showed m RNA relative expression 2.19 times higher than wild-genotype carriers. The TLR2 protein expression was also higher for the TLR2-196 to-174 del variant carriers [117 ± 10 arbitrary unit(a.u.) vs 95 ± 4 a.u., P = 0.03]. However, for the TLR4-1607T/C polymorphism no significant difference was found for both m RNA(P = 0.56) and protein expression(P = 0.26).CONCLUSION: Our findings suggest that TLR2-196 to-174 del polymorphism increases TLR2 m RNA expression and is associated with higher CRC risk, indicating an important role in CRC genetic susceptibility.展开更多
基金Supported by Sao Paulo Research Foundation(FAPESP),No.2012/15036-8National Council for Scientific and Technological Development(CNPq),No.474.776/2013-1+2 种基金the Sao Paulo Research Foundation(FAPESP,NO.2015/21464-0)for the support for English revisionthe Coordination for the Improvement of Higher Education Personnel(CAPES)for the doctoral scholarshipthe National Council for Scientific and Technological Development(CNPq,NO.310120/2015-2)for the productivity research scholarship
文摘AIM To examine the effect of Fusobacterium nucleatum(F. nucleatum) on the microenvironment of colonic neoplasms and the expression of inflammatory mediators and microRNAs(miRNAs).METHODS Levels of F. nucleatum DNA, cytokine gene mRNA(TLR2, TLR4, NFKB1, TNF, IL1 B, IL6 and IL8), and potentially interacting miRNAs(miR-21-3p, miR-22-3p, mi R-28-5p, miR-34a-5p, miR-135b-5p) were measured by quantitative polymerase chain reaction(qPCR) TaqMan? assays in DNA and/or RNA extracted from the disease and adjacent normal fresh tissues of 27 colorectal adenoma(CRA) and 43 colorectal cancer(CRC) patients. KRAS mutations were detected by direct sequencing and microsatellite instability(MSI) status by multiplex PCR. Cytoscape v3.1.1 was used to construct the postulated miRNA:mRNA interaction network.RESULTS Overabundance of F. nucleatum in neoplastic tissue compared to matched normal tissue was detected in CRA(51.8%) and more markedly in CRC(72.1%). We observed significantly greater expression of TLR4, IL1 B, IL8, and miR-135 b in CRA lesions and TLR2, IL1 B, IL6, IL8, mi R-34 a and miR-135 b in CRC tumours compared to their respective normal tissues. Only two transcripts for miR-22 and miR-28 were exclusively downregulated in CRC tumour samples. The mRNA expression of IL1 B, IL6, IL8 and miR-22 was positively correlated with F. nucleatum quantification in CRC tumours. The mRNA expression of miR-135 b and TNF was inversely correlated. The miRNA:mRNA interaction network suggested that the upregulation of miR-34 a in CRC proceeds via a TLR2/TLR4-dependent response to F. nucleatum. Finally, KRAS mutations were more frequently observed in CRC samples infected with F. nucleatum and were associated with greater expression of miR-21 in CRA, while IL8 was upregulated in MSI-high CRC.CONCLUSION Our findings indicate that F. nucleatum is a risk factor for CRC by increasing the expression of inflammatory mediators through a possible mi RNA-mediated activation of TLR2/TLR4.
基金Supported by Grants from Brazilian agencies FAPESP,No.2012/15036-8and CNPq,No.304870/2012-9
文摘AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor(TLR)2-196 to-174 del and TLR4-1607T/C(rs10759932) on m RNA and protein expression in tumor tissue and of TLR4+896A/G(rs4986790) on colorectal cancer(CRC) risk.METHODS: The TLR2-196 to-174 del polymorphism was investigated using allele-specific polymerase chain reaction(PCR) and the TLR4-1607T/C and TLR4+896A/G by PCR-restriction fragment length p o l y m o r p h i s m( R F L P). W e g e n o t y p e d 4 3 4 D N A samples from 194 CRC patients and 240 healthy individuals. The m RNA relative quantification(RQ) was performed in 40 tumor tissue samples by quantitative PCR Taq Man assay, using specific probes for TLR2 and TLR4 genes, and ACTB and GAPDH reference geneswere used as endogenous controls. Protein expression was analyzed by immunohistochemistry with specific primary antibodies.RESULTS: No association was found for TLR4-1607T/C and TLR4+896A/G by three statistical models(logadditive, dominant and recessive). However, based on dominant and log-additive models, the polymorphic variant TLR2-196 to-174 del was associated with increased CRC risk [dominant: odds ratio(OR) = 1.72, 95%CI: 1.03-2.89; P = 0.038 and log-additive: OR =1.59, 95%CI: 1.02-2.48; P = 0.039]. TLR2 m RNA expression was increased in tumor tissue(RQ = 2.36) when compared to adjacent normal tissue(RQ = 1; P < 0.0001), whereas the TLR4 m RNA showed a basal expression(RQ = 0.74 vs RQ = 1, P = 0.452). Immunohistochemistry analysis of TLR2 and TLR4 protein expression was concordant with the findings of m RNA expression. In addition, the TLR2-196 to-174 del variant carriers showed m RNA relative expression 2.19 times higher than wild-genotype carriers. The TLR2 protein expression was also higher for the TLR2-196 to-174 del variant carriers [117 ± 10 arbitrary unit(a.u.) vs 95 ± 4 a.u., P = 0.03]. However, for the TLR4-1607T/C polymorphism no significant difference was found for both m RNA(P = 0.56) and protein expression(P = 0.26).CONCLUSION: Our findings suggest that TLR2-196 to-174 del polymorphism increases TLR2 m RNA expression and is associated with higher CRC risk, indicating an important role in CRC genetic susceptibility.
