Role of CD14 promoter polymorphisms in Helicobacter pylori infection--related gastric carcinoma

Regulation of the migration of colorectal cancer stem cells via the TLR4/MyD88 signaling pathway by the novel surface marker CD14 following LPS stimulation

Cell surface markers are most widely used in the study of cancer stem cells (CSCs). However, cell surface markers that are safely and stably expressed in CSCs have yet to be identified. Colonic CSCs express leukocyte CD14. CD14 binding to the ligand lipopolysaccharide (LPS) is involved in the inflammatory response via the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway. TLR4 and MyD88 have been reported to promote the proliferation, metastasis and tumorigenicity of colon cancer cells, which is consistent with the characteristics of CSCs. In the present study, the proposed experimental method to detect cell proliferation, metastasis and tumorigenesis was used to confirm that, under LPS stimulation, CD14 promoted the proliferation, migration and tumorigenesis of colonic CSCs via the TLR4/MyD88 signaling pathway. Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine assays were used to assess the proliferation and migration of the cells. Colony formation and nude mouse xenograft assays were used to assess the capacity of cells to form tumors. Using western blotting and reverse transcription-quantitative PCR, the mRNA and protein levels of CD14, TLR4 and MyD88 were examined. It was confirmed that CD14 promoted the proliferation, metastasis and tumorigenesis of colon CSCs in response to LPS stimulation via the TLR4/MyD88 signaling pathway, and CD14+ colon cancer cells were successfully isolated and sorted. According to the results of proliferation assay, it was determined that CD14 regulated the LPS-induced proliferation of colon CSCs. CD14, TLR4 and MyD88 protein and mRNA expression was upregulated in colon CSCs in response to LPS stimulation. This indicates a potential novel target for colon CSC-related studies.

LINC01226 promotes gastric cancer progression through enhancing cytoplasm-to-nucleus translocation of STIP1 and stabilizing β-catenin protein

Gastric cancer (GC) remains one of the most common malignances and the leading cause of cancer-related mortality worldwide. Although the critical role of several long non-coding RNAs (lncRNAs) transcribed from several GC-risk loci has been established, we still know little about the biological significance of these lncRNAs at most gene loci and how they play in cell signaling. In the present study, we identified a novel oncogenic lncRNA LINC01226 transcribed from the 1p35.2 GC-risk locus. LINC01226 shows markedly higher expression levels in GC specimens compared with those in normal tissues. High expression of LINC01226 is evidently correlated with worse prognosis of GC cases. In line with these, oncogenic LINC01226 promotes proliferation, migration and metastasis of GC cells ex vivo and in vivo. Importantly, LINC01226 binds to STIP1 protein, leads to disassembly of the STIP1-HSP90 complex, elevates interactions between HSP90 and β-catenin, stabilizes β-catenin protein, activates the Wnt/β-catenin signaling and, thereby, promote GC progression. Together, our findings uncovered a novel layer regulating the Wnt signaling in cancers and uncovers a new epigenetic mode of GC tumorigenesis. These discoveries also shed new light on the importance of functional lncRNAs as innovative therapeutic targets through precisely controlling protein-protein interactions in cancers.

Plasma Exosome Proteins ILK1 and CD14 Correlated with Organ-Specific Metastasis in Advanced Gastric Cancer Patients

The exosome plays important roles in driving tumor metastasis, while the role of exosome proteins during organ-specific metastasis in gastric cancer has not been fully understood. To address this question, peripheral blood samples from 12 AGC patients with organ-specific metastasis, including distant lymphatic, hepatic and peritoneal metastasis, were collected to purify exosomes and to detect exosome proteins by Nano-HPLC-MS/MS. Gastric cancer cell lines were used for in vitro experiments. Peripheral blood sample and ascites sample from one patient were further analyzed by single-cell RNA sequencing. GO and KEGG enrichment analysis showed different expression proteins of hepatic metastasis were correlated with lipid metabolism. For peritoneal metastasis, actin cytoskeleton regulation and glycolysis/gluconeogenesis could be enriched. ILK1 and CD14 were correlated with hepatic and peritoneal metastasis, respectively. Overexpression of CD14 and ILK1 impacted the colony formation ability of gastric cancer and increased expression of Vimentin. CD14 derived from immune cells in malignant ascites correlated with high activation of chemokine- and cytokine-mediated signaling pathways. In summary, biological functions of plasma exosome proteins among AGC patients with different metastatic modes were distinct, in which ILK1 and CD14 were correlated with organ-specific metastasis.

Improved profiling of low molecular weight serum proteome for gastric carcinoma by data-independent acquisition

Low molecular weight proteins (LMWPs) in the bloodstream participate in various biological processes and are closely associated with disease status, whereas identification of serous LMWPs remains a great technical challenge due to the wide dynamic range of protein components. In this study, we constructed an integrated LMWP library by combining the LMWPs obtained by three enrichment methods (50% ACN, 20% ACN + 20 mM ABC, and 30 kDa) and their fractions identified by the data-dependent acquisition method. With this newly constructed library, we comprehensively profiled LMWPs in serum using data-independent acquisition and reliably achieved quantitative results for 75% serous LMWPs. When applying this strategy to quantify LMWPs in human serum samples, we could identify 405 proteins on average per sample, of which 136 proteins were with a MW less than 30 kDa and 293 proteins were with a MW less than 65 kDa. Of note, pre- and post-operative gastric carcinoma (GC) patients showed differentially expressed serous LWMPs, which was also different from the pattern of LWMP expression in healthy controls. In conclusion, our results showed that LMWPs could efficiently distinguish GC patients from healthy controls as well as between pre- and post-operative statuses, and more importantly, our newly developed LMWP profiling platform could be used to discover candidate LMWP biomarkers for disease diagnosis and status monitoring.

Association of CD14 gene -260C>T and -561C>T polymorphisms with cancer susceptibility: A meta-analysis

BACKGROUND

Two polymorphisms, -260C>T (rs2569190) and -561C>T (rs5744455), in the CD14 gene have been implicated in susceptibility to cancer. However, the results remain inconclusive. The current meta-analysis was carried out aiming to confirm the function of these two polymorphisms on the susceptibility of cancer.

METHODS

We collected eligible studies from databases, including PubMed, EMBASE, CNKI, Wanfang, and VIP (Weipu). We used logistic regression calculation to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

After strict selection, 24 studies with 5854 cases and 10339 controls for -260C>T and seven studies with 1809 cases and 7289 controls for -561C>T were finally enlisted into our analysis reference material. Pool results revealed that neither -260C>T, nor -561C>T was found to have any association with overall cancer susceptibility. Nevertheless, when stratified by cancer type, we detected a decreased risk associated with other cancers in a heterozygous model (OR = 0.69, 95% CI = 0.51-0.93, p = 0.014) and a dominant model (OR = 0.70, 95% CI = 0.53-0.93, p = 0.012) for -561C>T. An increased risk was found in other cancers under an allele model (OR = 1.29, 95% CI = 1.03-1.62, p = 0.026), in laryngeal cancer under a dominant model (OR = 1.38, 95% CI = 1.11-1.71, p = 0.003) and for a score ≤ 9 under a recessive model (OR = 1.45, 95% CI = 1.09-1.91, p = 0.009) for -561C>T.

CONCLUSIONS

In the present study, we conclude that the CD14 -260C>T and -561C>T polymorphisms might not be associated with overall cancer risk. Further studies are encouraged to confirm this conclusion.

Correlation between MBL2/CD14/TNF-α gene polymorphisms and susceptibility to spinal tuberculosis in Chinese population

Objective: The present study investigated the clinical significance of mannose-binding lectin 2 (MBL2), cluster of differentiation 14 (CD14) and tumour necrosis factor-α (TNF-α) gene polymorphisms in patients with spinal tuberculosis (TB) in Chinese population. Methods: A total of 240 patients with spinal TB were enrolled in the present study from May 2013 to August 2016 at Hangzhou Red Cross Hospital. A total of 150 age- and sex-matched healthy subjects were enrolled as controls. The genomic DNA was extracted from the peripheral blood of all subjects, and the MBL2, CD14 and TNF-α gene polymorphisms were detected by direct DNA sequencing. Results: (1) Compared with controls, patients with spinal TB exhibited a significantly higher frequency of the XY genotype at the −221G>C polymorphism as well as the Q allele and PQ genotype or an association with the QQ genotype at the +4C>T polymorphism in the MBL2 gene. (2) Compared with controls, patients with spinal TB exhibited a significantly higher frequency of the T allele and TT genotype or an association with the CT genotype at the −159C>T polymorphism in the CD14 gene. (3) Compared with controls, patients with spinal TB exhibited a significantly higher frequency of the T allele and the CT genotype or an association with the TT genotype at the TNF-857 polymorphism in the TNF-α gene. Conclusion: The −221G>C polymorphism of MBL2, the −159C>T polymorphism of CD14 and the TNF-857 polymorphism of TNF-α are risk factors for spinal TB and may be involved in the development of spinal TB in the Chinese population. These factors are indicators of susceptibility to spinal TB and require clinical attention.

Lipopolysaccharide-pathway proteins are associated with gallbladder cancer among adults in Shanghai, China with mediation by systemic inflammation

PURPOSE

We examined inflammation as a mediator of associations between bacterial infection markers and gallbladder cancer (GBC).

METHODS

Bacterial response proteins (lipopolysaccharide [LPS], soluble cluster of differentiation 14 [sCD14], and LPS-binding protein [LBP]) were measured in 40 GBC cases and 126 gallstone controls with data on 63 serum inflammation markers. The relationships of LPS, LBP, and sCD14 with GBC were examined by logistic regression, which also was used to evaluate whether these associations are influenced by systemic inflammation as measured by a combinatorial inflammation score.

RESULTS

The third versus the first tertiles of sCD14 and of LBP were associated with an increased GBC risk (odds ratio [95% confidence interval]: 5.41 [2.00-16.75] for sCD14, and 6.49 [2.24-23.79] for LBP). sCD14 and LBP were strongly associated with inflammation score (above vs. below the median), which itself was associated with a more than 21-fold increased risk of GBC for the third versus first tertiles. Associations between GBC and sCD14 and LBP were markedly attenuated when the inflammation score was included in the model. While LPS was not associated with GBC or inflammation, only 35% of cases and 22% of controls had detectable levels.

CONCLUSIONS

These findings suggest that these LPS-pathway proteins are associated with GBC via inflammation-related pathways.

Association between CD14 SNP -159 C/T and gastric cancer: an independent case-control study and an updated meta-analysis

PURPOSE

The association between CD14 -159C/T polymorphism and the susceptibility to gastric cancer (GC) has been reported. However, the results were inconclusive. In the present study, a case-control study and a meta-analysis were performed to assess the possible association between -159C/T in the CD14 gene and GC risk.

PATIENTS AND METHODS

Relevant studies were searched in several databases including PubMed, Web of Science, EMBASE, Chinese National Knowledge Infrastructure database, and Wanfang database (last search was performed on December 30, 2015). In addition, a case-control study involving 164 GC cases and 169 controls was also performed in the analysis. Statistical analysis was performed by the software Revman5.3.

RESULTS

A total of ten published studies and the present case-control study involving 2,844 GC and 3,983 controls were included for the meta-analysis. The analysis result indicated that the T allele of CD14 -159C/T polymorphism did not confer risk for GC (in our study: [P=0.93]; in the meta-analysis: T vs 2N odds ratio =1.28 and 95% confidence interval (CI) =0.95-1.24, [P=0.24]). However, we found a significant association in the recessive model (in our study: TT vs TC+CC [P=0.04]; in the meta-analysis: TT vs TC+CC odds ratio =1.12 and 95% CI =1.01-1.26, [P=0.04]). Furthermore, a subgroup analysis by ethnicity showed that TT genotype was significantly associated with GC in Asian (odds ratio =1.17 and 95% CI =1.02-1.34, [P=0.02]) but not in Caucasian.

CONCLUSION

Our results highlight the TT genotype of CD14 -159C/T as a genetic susceptibility factor for gastric cancer, particularly, in Asians and population-based controls.

CD14 knockdown reduces lipopolysaccharide-induced cell viability and expression of inflammation-associated genes in gastric cancer cells in vitro and in nude mouse xenografts

The present study examined the role of CD14 in the regulation of lipopolysaccharide (LPS)-induced effects on gastric cancer cells. MGC‑803 cells were stably transfected with CD14 short hairpin (sh)RNA and treated with LPS, followed by assessment of cell proliferation, apoptosis and gene expression using a cell counting kit‑8 assay, flow cytometry, reverse transcription‑polymerase chain reaction and western blot analysis, respectively. The cells subjected to CD14 knockdown were treated with 10 g/ml LPS and injected into nude mice to form tumor xenografts. CD14 shRNA‑transfected MGC‑803 cells did not exhibit any significant changes in cell viability compared with the control cells (P>0.05), but cell viability was markedly increased in the wild‑type (WT) + LPS group (P<0.05). In contrast to the WT + LPS group, the cell viability of the sh‑CD14 + LPS group was markedly decreased (P<0.05). In addition, compared with those in the controls, the level of sh‑CD14 cell apoptosis did not change significantly; however, it was markedly reduced in the LPS group. Compared with that in the WT + LPS group, the rate of apoptosis in the sh‑CD14 + LPS group increased to a certain extent, while it remained lower in the control group. In addition, compared with that in the control, the expression of tumor necrosis factor‑α, interleukin (IL)‑1, IL‑6 and IL‑12, and human β‑defensin 2 was significantly increased in the WT + LPS group, while, compared with that in the WT + LPS group, the expression of these genes was markedly reduced in the sh‑CD14 + LPS group (P<0.05). The nude mouse experiments further confirmed the in vitro data, including the finding that LPS promoted the growth of xenografts, but knockdown of CD14 expression reduced the response of tumor cells to LPS treatment. In conclusion, LPS induced cell viability and the release of inflammatory cytokines, but inhibited gastric cancer cell apoptosis. Knockdown of CD14 expression had no significant effect on gastric cancer malignancy, but mediated LPS signal transduction.

Functional genetic variants of TNFSF15 and their association with gastric adenocarcinoma: a case-control study

The purpose of this study was to identify functional genetic variants in the promoter of tumor necrosis factor superfamily member 15 (TNFSF15) and evaluate their effects on the risk of developing gastric adenocarcinoma. Forty DNA samples from healthy volunteers were sequenced to identify single nucleotide polymorphisms (SNPs) in the TNFSF15 promoter. Two TNFSF15 SNPs (−358T>C and −638A>G) were identified by direct sequencing. Next, genotypes and haplotypes of 470 gastric adenocarcinoma patients and 470 cancer-free controls were analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression. Serologic tests for Helicobacter pylori infection were measured by enzyme-linked immuno-sorbent assay (ELISA). Subjects carrying the TNFSF15 −358CC genotype were at an elevated risk for developing gastric adenocarcinoma, compared with those with the −358TT genotype (OR 1.42, 95% CI, 1.10 to 2.03). H. pylori infection was a risk factor for developing gastric adenocarcinoma (OR 2.31, 95% CI, 1.76 to 3.04). In the H. pylori infected group, subjects with TNFSF15 −358CC genotype were at higher risks for gastric adenocarcinoma compared with those carrying −358TT genotype (OR: 2.01, 95%CI: 1.65 to 4.25), indicating that H. pylori infection further influenced gastric adenocarcinoma susceptibility. The −358 T>C polymorphism eliminates a nuclear factor Y (NF-Y) binding site and the −358C containing haplotypes showed significantly decreased luciferase expression compared with −358T containing haplotypes. Collectively these findings indicate that functional genetic variants in TNFSF15 may play a role in increasing susceptibility to gastric adenocarcinoma.

Pattern-recognition receptors and gastric cancer

Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy.

Association between CD14 gene polymorphisms and cancer risk: a meta-analysis

Background

Two polymorphisms, -260C/T and -651C/T, in the CD14 gene have been implicated in susceptibility to cancer. However, the results remain inconclusive. This meta-analysis aimed to investigate the association between the two polymorphisms and risk of cancer.

Methods

All eligible case-control studies published up to March 2014 were identified by searching PubMed, Web of Science, CNKI and WanFang database. Pooled odds ratio (OR) with 95% confidence interval (CI) were used to access the strength of this association in fixed- or random-effects model.

Results

17 case-control studies from fourteen articles were included. Of those, there were 17 studies (4198 cases and 4194 controls) for -260C/T polymorphism and three studies (832 cases and 1190 controls) for -651C/T polymorphism. Overall, no significant associations between the two polymorphisms of CD14 gene and cancer risk were found. When stratified by ethnicity, cancer type and source of control, similar results were observed among them. In addition, in further subgroups analysis by Helicobacter pylori (H. pylori) infection status and tumor location in gastric cancer subgroup, we found that the CD14 -260C/T polymorphism may increase the risk of gastric cancer in H. pylori-infected individuals.

Conclusions

This meta-analysis suggests that the CD14 -260C/T polymorphism may increase the risk of gastric cancer in H. pylori-infected individuals. However, large and well-designed studies are warranted to validate our findings.

Genetic polymorphisms in the Toll-like receptor signalling pathway in Helicobacter pylori infection and related gastric cancer

BACKGROUND

Gastric cancer (GC) is a progressive process initiated by Helicobacter pylori-induced inflammation. Initial recognition of H. pylori involves Toll-like receptors (TLRs), central molecules in the host inflammatory response. Here, we investigated the association between novel polymorphisms in genes involved in the TLR signalling pathway, including TLR2, TLR4, LBP, MD-2, CD14 and TIRAP, and risk of H. pylori infection and related GC.

METHODS

A case-control study comprising 310 ethnic Chinese individuals (87 non-cardia GC cases and 223 controls with functional dyspepsia) was conducted. Twenty-five polymorphisms were detected by MALDI-TOF mass spectrometry, PCR, PCR-RFLP and real-time PCR.

RESULTS

Seven polymorphisms showed significant associations with GC (TLR4 rs11536889, TLR4 rs10759931, TLR4 rs1927911, TLR4 rs10116253, TLR4 rs10759932, TLR4 rs2149356 and CD14 -260 C/T). In multivariate analyses, TLR4 rs11536889 remained a risk factor for GC (OR: 3.58, 95% CI: 1.20-10.65). TLR4 rs10759932 decreased the risk of H. pylori infection (OR: 0.59, 95% CI: 0.41-0.86). Statistical analyses assessing the joint effect of H. pylori infection and the selected polymorphisms revealed strong associations with GC (TLR2, TLR4, MD-2, LBP and TIRAP polymorphisms).

CONCLUSIONS

Novel polymorphisms in TLR2, TLR4, MD-2, LBP, CD14 and TIRAP, genes encoding important molecules of the TLR signalling pathway, showed clear associations with H. pylori-related GC in Chinese.

The association between CD14-260C/T polymorphism and malignant tumor risk: a meta-analysis of 5,603 participants

The CD14-260C/T polymorphism has been implicated to be in association with malignant tumor. However, a number of studies have reported inconclusive results. The aim of this study was to investigate the relationship of CD14-260C/T polymorphism and malignant tumor risk by meta-analysis. A search was performed in PubMed, Embase, the Chinese Journals Full-text Database (CNKI), and Wanfang databases up to August 2013. Odds ratio (OR) and 95 % confidence interval (95 % CI) were used to assess the association. Statistical analysis was calculated by STATA 11.0 software. The polymorphism was identified from 11 articles (12 case-control studies), involving 2,660 cases and 2,943 controls. Overall, no significant association between CD14-260C/T polymorphism and malignant tumor risk was found in the dominant model (TT + TC vs. CC: OR = 0.86, 95 % CI = 0.67-1.11). In the subgroup analysis by malignant tumor types, we found that the heterozygote model (TC vs. CC) might reduce the risk of malignant tumor, especially hematological malignance and prostate cancer (OR = 0.67, 95 % CI = 0.47-0.95), but not associated with gastrointestinal cancer susceptibility. In the subgroup analysis by ethnicity, no significant associations were found among different ethnicities. The study suggested that CD14-260C/T polymorphism might be a protective factor for hematological malignance and prostate tumor susceptibility but not an independent risk factor for gastrointestinal cancer susceptibility. To further evaluate the association between the polymorphism and malignant tumor susceptibility, more studies involving thousands of patients are required.

Association of CD14/-260 polymorphism with gastric cancer risk in Highland Tibetans

AIM: To investigate the relationship between CD14-260 and -651 polymorphisms and the risk of developing gastric cancer.

METHODS: DNA was extracted from peripheral blood samples obtained from 225 Tibetans with gastric cancer and 237 healthy Tibetans, and analyzed using the polymerase chain reaction/ligase detection (PCR/LDR) method to determine the genotypes at -260 and -651 loci of the CD14 promoter. The allele frequencies, genotype frequencies, and haplotypes were analyzed for their association with gastric cancer risk using online SHEsis software. The luciferase reporter assay and point mutation analysis were used to construct in vitro plasmids expressing a C/T homozygote at the -260 locus of the CD14 promoter.

RESULTS: The frequencies of CC, CT and TT genotypes in the CD14-260 C/T locus in gastric cancer patients were 19.1%, 38.7% and 42.2%, respectively, whereas they were 33.3%, 32.5% and 34.2%, respectively, in healthy control subjects. CT genotype carriers were more frequently found among gastric cancer patients than healthy controls (OR = 2.076; 95%CI: 1.282-3.360). Also, TT genotype carriers were more frequently found among gastric cancer patients (OR = 2.155; 95%CI: 1.340-3.466). Compared to the C allele of CD14/-260, the T allele was associated with an increased risk for gastric cancer (OR = 1.574; 95%CI: 1.121-2.045). Furthermore, the frequencies of CC, CT and TT in the CD14-651 C/T locus in gastric cancer patients were 64.4%, 29.3% and 6.2%, respectively, while they were 56.5%, 35.0% and 8.4%, respectively, in the healthy control subjects (P > 0.05). Data obtained using the luciferase reporter assay showed that the p260T homozygote was associated with greater CD14 promoter activity (P < 0.01).

CONCLUSION: CD14/-260 polymorphism is associated with gastric cancer risk in Highland Tibetans and affects CD14 promoter activity, thereby regulating CD14 expression.

Polymorphisms of Helicobacter pylori signaling pathway genes and gastric cancer risk in the European Prospective Investigation into Cancer-Eurgast cohort

Helicobacter pylori is a recognized causal factor of noncardia gastric cancer (GC). Lipopolysaccharide and peptidoglycan of this bacterium are recognized by CD14, TLR4 and NOD2 human proteins, while NFKB1 activates the transcription of pro-inflammatory cytokines to elicit an immune response. Single nucleotide polymorphisms (SNPs) in these genes have been associated with GC in different populations. We genotyped 30 SNPs of these genes, in 365 gastric adenocarcinomas and 1,284 matched controls from the European Prospective Investigation into Cancer cohort. The association with GC and its histological and anatomical subtypes was analyzed by logistic regression and corrected for multiple comparisons. Using a log-additive model, we found a significant association between SNPs in CD14, NOD2 and TLR4 with GC risk. However, after applying the multiple comparisons tests only the NOD2 region remained significant (p = 0.009). Analysis according to anatomical subtypes revealed NOD2 and NFKB1 SNPs associated with noncardia GC and CD14 SNPs associated with cardia GC, while analysis according to histological subtypes showed that CD14 was associated with intestinal but not diffuse GC. The multiple comparisons tests confirmed the association of NOD2 with noncardia GC (p = 0.0003) and CD14 with cardia GC (p = 0.01). Haplotype analysis was in agreement with single SNP results for NOD2 and CD14 genes. From these results, we conclude that genetic variation in NOD2 associates with noncardia GC while variation in CD14 is associated with cardia GC.

The -159C/T polymorphism in the CD14 gene and cancer risk: a meta-analysis

Purpose

The -159C/T polymorphism in the cluster of differentiation (CD)14 gene has been extensively studied for an association with cancer; however, results from replication studies have been inconclusive. The aim of this study was to perform a comprehensive assessment of the possible association between the -159C/T polymorphism in the CD14 gene and cancer risk, by meta-analysis.

Methods

We searched in PubMed, Embase, and other databases, covering all case-control studies on the possible association between CD14 -159C/T gene polymorphism and cancer risk. Data were extracted and statistical analyses were performed using RevMan 5.0 and STATA 12.0 software.

Results

A total of 12 case-control studies met our inclusion criteria, including 2,498 cases and 2,696 controls. The combined analysis indicated that the CD14 -159C/T gene polymorphism didn’t confer risk for cancer – the recessive model (TT versus (vs) CT + CC), showed odds ratio (OR) =1.01, 95% confidence interval (CI) =0.82–1.23 (P=0.94), while the dominant model (TT + TC vs CC) showed OR =0.81, 95% CI =0.66–1.00 (P=0.05). A subgroup analysis by ethnicity showed that the cancer risk associated with CD14 -159C/T gene polymorphism was significantly decreased among Caucasians for the TC + TT vs CC comparison (OR =0.83, 95% CI =0.70–0.98 [P=0.03]). The subgroup analysis by cancer type suggested that the CD14 -159C/T gene polymorphism was not associated with gastric cancer risk.

Conclusion

The evidence from the present meta-analysis did not support the CD14 -159C/T gene polymorphism as a genetic risk factor for cancer. Further studies on different cancer types and ethnicities are needed to validate our findings.

Risk of Atherosclerosis and Helicobacter pylori Infection according to CD14 Promotor Polymorphism in Healthy Korean Population

Background and Aim. We aim to elucidate the association of risk factors for atherosclerosis and H. pylori infection according to the promotor polymorphism of the CD14 gene in healthy Korean population. Methods. The patients who visited our hospital for routine health examinations and 266 healthy adults (170 males and 96 females) were enrolled in this study. The promotor polymorphism at -159C/T of the CD14 gene was determined by PCR-restriction fragment length polymorphism analysis. According to genetic polymorphism and H. pylori infection, we analyzed the risk of atherosclerosis. Results. The genotype frequencies were CC 7.9%, CT 45.1%, and TT 47.0%, respectively. There were no differences between specific genotypes of CD14 gene and H. pylori infection rate. As for HDL cholesterol level, there were significant differences among the three genotypes (P < 0.01). In subjects with H. pylori infection, no significant differences were observed between specific genotypes of CD14 gene and the risk factors of atherosclerosis. Conclusion. The promotor polymorphism at -159C/T of the CD14 gene was associated with the risk factor of atherosclerosis in healthy Korean population. However, it was not associated with the rate of H. pylori infection and H. pylori induced atherosclerotic risk.

CD14 regulates gastric cancer cell epithelial‑mesenchymal transition and invasion in vitro

Cluster of differentiation 14 (CD14) protein functions as a co-receptor with either the Toll-like receptor TLR4 or MD-2 in the detection of bacterial lipopolysaccharide (LPS) and plays a role in the innate immune system. Recently, it was shown to have effects on the regulation of epithelial-mesenchymal transition (EMT). Thus, the present study investigated the effects of CD14 knockdown on the regulation of gastric cancer cell EMT and invasive capacity following treatment with or without LPS. Knockdown of CD14 expression using CD14 shRNA in MGC-803 cells significantly enhanced E-cadherin expression, but reduced N-cadherin and vimentin expression in both LPS-treated and untreated cells. Morphologically, the phenotype of LPS-treated CD14-knockdown cells was altered to a sporadic long spindle shape. Moreover, TNF-α-treated cells were further elongated, connections between cells were reduced, the gap between the cells was increased and the cells were transformed into mesenchymal cells. Furthermore, the invasive capacity of CD14-knockdown cells was significantly lower compared to that of the negative control shRNA-transfected MGC-803 cells. LPS-treated CD14-knockdown cells had significantly lower levels of tumor cell invasive ability when compared to the LPS-treated parental MGC-803 cells. However, addition of TNF-α to LPS-treated CD14-knockdown cells significantly increased tumor cell invasion. This study demonstrated that CD14 promoted tumor cell EMT and invasion through TNF-α, whereas knockdown of CD14 expression inhibited gastric cancer cell invasion and EMT.

Helicobacter pylori Infection Enhances Gastric Mucosal Inflammation in Individuals Carrying the 260-T Allele of the CD14 Gene

BACKGROUND/AIMS

We aim to evaluate the association between promoter polymorphism of the clusters of differentiation 14 (CD14) gene and Helicobacter pylori-induced gastric mucosal inflammation in a healthy Korean population.

METHODS

The study population consisted of 267 healthy subjects who visited our hospital for free nationwide gastric cancer screening. Promoter polymorphism at -260 C/T of the CD14 gene was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. The severity of gastric mucosal inflammation was estimated by a gastritis score based on the sum of the values of the grade and activity of the gastritis. Expression of soluble CD14 (sCD14) was assessed by quantitative sandwich ELISA.

RESULTS

CD14 polymorphism was not associated with H. pylori infection. There were no significant differences in gastritis scores among the genotype subgroups, but subjects carrying the CD14 -260 CT/TT genotype had significantly higher sCD14 levels than those carrying the CC genotype. Subjects with the 260-T allele of the CD14 gene and H. pylori infection had significantly higher sCD14 levels than those with the same genotype but without infection.

CONCLUSIONS

In individuals with the T allele at the -260 site of the promoter region of the CD14 gene, H. pylori infection accentuates gastric mucosal inflammation.

The role of TLR2, TLR4 and CD14 genetic polymorphisms in gastric carcinogenesis: a case-control study and meta-analysis

Background

In addition to Helicobacter pylori infection, host genetic factors contribute to gastric cancer (GC). Recognition of H. pylori is known to involve Toll-like receptors (TLR), which subsequently leads to activation of NF-κB. Thus, the overall aim of this study was to estimate for the first time the pooled effect size of polymorphisms in TLR2, TLR4 and CD14 on GC development through a meta-analysis.

Methods

A case-control study comprising 284 ethnic Chinese individuals (70 non-cardia GC cases and 214 functional dyspepsia controls) was conducted for the genotyping of TLR2 -196 to -174del, CD14 -260 C/T and TLR4 rs11536889 using PCR, RT-PCR and mass spectrometry. Case-control studies of TLR2, TLR4 and CD14 polymorphisms and GC were searched up to June 2012. Pooled odds ratios and 95% confidence intervals were obtained by means of the random effects model.

Results

In our ethnic Chinese case-control study, the TLR4 rs11536889 C allele increased the risk of GC (OR: 1.89, 95%CI: 1.23–2.92) while the CD14 -260 T allele was protective (OR: 0.62, 95%CI: 0.42–0.91). TLR2 -196 to -174 increased the risk of GC only in H. pylori-infected individuals (OR: 3.10, 95%CI: 1.27–7.60). In the meta-analysis, TLR4 Asp299Gly showed borderline results in the general analysis (pooled OR: 1.58, 95%CI: 0.98–2.60), nevertheless, stratified analysis by ethnicity showed that the mutant allele was a definitive risk factor for GC in Western populations (pooled OR: 1.87, 95%CI: 1.31–2.65). There was a potential association between the TLR2 -196 to -174 deletion allele and GC in Japanese (pooled OR: 1.18, 95%CI: 0.96–1.45). TLR4 Thr399Ile did not provide significant results.

Conclusions

TLR4 rs11536889 and CD14 -260 C/T are associated with non-cardia GC in Chinese. Based on our meta-analysis, the TLR signalling pathway is involved in gastric carcinogenesis, TLR4 Asp299Gly and TLR2 -196 to -174del showing associations with GC in an ethnic-specific manner.

CD14 overexpression upregulates TNF-α-mediated inflammatory responses and suppresses the malignancy of gastric carcinoma cells

CD14 mediates the inflammatory response via recognition of lipopolysaccharide, which has been implicated in Helicobacter pylori (H. pylori) infections. Increasing evidence has suggested that CD14 status significantly influences the clinical outcome of H. pylori infection, which can result in gastric carcinoma. However, there is little evidence regarding the cellular impact and associated molecular basis of CD14 on gastric carcinoma cells. To address this question, we generated a CD14-overexpressing SGC-7901 gastric carcinoma cell line and analyzed the impact of CD14 expression. Our results revealed that cells overexpressing CD14 exhibited antitumor potential, including significantly decreased clonogenic ability, proliferation, metastatic invasion, as well as enhanced apoptosis, suggesting a tumor-suppressive role of CD14 in the cells. Intriguingly, we further discovered that CD14 overexpression activated NF-κB via upregulating its expression and simultaneously stimulating DNA binding activity. Upregulated NF-κB transcriptionally elevated a series of pro-inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-12. Together, the current study utilized a CD14-overexpressing gastric cell model to determine the impacts of CD14 upregulation on cell viability, apoptosis, and migration and NF-κB-mediated inflammation.

Effect of PSCA gene polymorphisms on gastric cancer risk and survival prediction: A meta-analysis

Previous studies have shown that two single-nucleotide polymorphisms (SNPs) in PSCA (rs2976392 and rs2294008) are associated with gastric cancer (GC), but the results are conflicting. Additionally, the prognostic value of PSCA gene polymorphisms for GC patients is unknown. We performed a meta-analysis using 9 eligible case-control studies to investigate the association between PSCA polymorphisms and GC risk, and additionally investigated the prognostic value of PSCA polymorphisms for GC patients with two eligible studies. The association was measured using random-effect or fixed-effect odds ratios (ORs) combined with 95% confidence intervals (CIs) according to the heterogeneity of the studies. We found that rs2294008 (dominant model: OR, 1.44; 95% CI, 1.16-1.79) and rs2976392 (dominant model: OR, 1.41; 95% CI, 0.98-2.04) polymorphisms were associated with increased risk of GC, although the association of rs2976392 was not statistically significant. For rs2294008, the associations were all consistently significant among the different subgroups stratified by ethnicity and tumor location, but not significant in intestinal or diffuse subtypes. For rs2976392, the associations were consistently significant for the intestinal, diffuse and non-cardia subtypes, but not significant for the cardia subtype. Furthermore, two eligible studies reported inverse results of PCSA in predicting the survival of GC patients (HR, 0.75; 95% CI, 0.59-0.96; and HR, 2.12; 95% CI, 1.22-3.69, respectively). In conclusion, PSCA gene polymorphisms are associated with increased risk of GC and are correlated with the prognosis of GC patients. Future studies are required to evaluate the molecular mechanisms of PSCA polymorphisms in GC and validate the prognostic value in a larger number of patients.

Single nucleotide polymorphisms in the promoter of the gene encoding the lipopolysaccharide receptor CD14 are associated with bacterial diarrhea in US and Canadian travelers to Mexico

BACKGROUND

Under normal conditions, the expression of CD14, which is the principal receptor for bacterial lipopolysaccharide, is down-regulated in the intestinal mucosa but increases in response to inflammatory stimuli. The aim of the present study was to investigate whether fecal CD14 levels increased in response to infection with diarrheagenic Escherichia coli and whether single nucleotide polymorphisms (SNPs) in the CD14 gene were associated with an increased susceptibility to traveler's diarrhea (TD) in US visitors to Mexico.

METHODS

Six SNPs located at the promoter, exon, and untranslated regions of CD14 were typed in a prospective cohort study of 1360 visitors to Mexico at risk for TD. Stools from visitors with TD were studied for enteric pathogens by culture, colony hybridization, and polymerase chain reaction. Fecal soluble CD14 (sCD14) was measured in a subgroup of 203 adults with diarrhea and 66 healthy controls by enzyme-linked immunosorbent assay.

RESULTS

The minor allele frequencies for CD14 SNPs were significantly different among the various racial and ethnic groups studied. Two SNPs in the promoter region of CD14 (-159 C > T; rs2569190 and -4191 C > T; rs5744441) were found to be associated with TD in White visitors. The -159 TT genotype was associated with a higher risk for TD (Relative risk [RR], 1.21; 95% confidence interval [CI], 1.05-1.38; P = .008), whereas individuals with the -4191 TT genotype were protected from infection (RR, 0.82; 95% CI, 0.71-0.92; P = .006). Subjects with TD excreted higher levels of fecal CD14 than did healthy controls (33,480 pg/mL vs 6178 pg/mL; P < .02). Fecal sCD14 levels were higher in stool samples from visitors with TD and the -159 TT genotype than they were in visitors with the CC/CT genotypes (P = .02), and stool samples from subjects with the -4191 CC genotype had higher fecal sCD14 levels than did stool samples from visitors with the CT/TT (P = .005) genotype. In a multivariate analysis with haplotypes constructed with the 6 SNPs studied, subjects with the haplotype containing the -159 C and the -4191 T allele were less likely to acquire TD (P = .015).

CONCLUSIONS

Our study suggests that CD14 levels increase in response to bacterial diarrhea and that polymorphisms in the CD14 gene influence susceptibility to TD. Intestinal CD14 plays an important role in the innate immune response to enteric pathogens.

A Genetic Variant of the CD14 C-159T in Patients with Functional Dyspepsia (FD) in Japanese Subjects

Inflammatory changes in the gastric mucosa are commonly observed in Japanese patients with functional dyspepsia (FD). However, detailed data regarding the relationship between the genetic regulatory factors of inflammation and FD are not available. CD14 is an important mediator of the inflammatory response in the first line of host defense by recognition of Lipopolysaccharide (LPS). We aimed to investigate the association between CD14 promoter C-159T polymorphism and FD in a Japanese population. 108 patients with FD and 99 non-dyspeptic subjects enrolled in this study. Dyspeptic symptoms were divided according to Rome III criteria. CD14 gene C-159T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. In the non-dyspeptics, the CD14 genotype distribution was 28CC (28.3%), 51CT (51.5%), 21TT (21.2%). Meanwhile, the CD14 genotype distribution in FD was 31CC (28.4%), 56CT (51.4%), 22TT (20.2%). The genotype distribution was not significantly different. There was no significant difference between two groups in the genotype distribution. We did not found any association between CD14 genotypes and dyspeptic patients in different gender and Helicobacter pylori infection status. No significant association was also found between CD14 polymorphism and any of different subtypes of FD according to Rome III while there was a weak correlation between TT genotype and PDS in male subjects (TT vs others, OR = 3.18, 95% CI = 0.98−10.26, p = 0.06). In conclusion, our results suggest that CD14 polymorphism is unlikely to associate with susceptibility of dyspeptic symptoms. The role of inflammation related-gene polymorphisms to the development of dyspepsia needs to further evaluation.

LBP and CD14 polymorphisms correlate with increased colorectal carcinoma risk in Han Chinese

AIM: To explore the associations of polymorphisms of lipopolysaccharide binding protein (LBP), cluster of differentiation 14 (CD14), toll-like receptor 4 (TLR-4), interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) with the colorectal carcinoma (CRC) risk in Han Chinese.

METHODS: Polymorphisms of LBP (rs1739654, rs2232596, rs2232618), CD14 (rs77083413, rs4914), TLR-4 (rs5030719), IL-6 (rs13306435) and TNF-α (rs35131721) were genotyped in 479 cases of sporadic colorectal carcinoma and 486 healthy controls of Han Chinese in a case-control study. Single-nucleotide polymorphisms (SNPs) between cases and controls were analyzed by unconditional logistic regression.

RESULTS: GA and GG genotypes of LBP rs2232596 were associated with a significantly increased risk of CRC [odds ratio (OR) = 1.51, 95% confidence interval (CI) 1.15-1.99, P = 0.003; OR = 2.49, 95% CI 1.16-5.38, P = 0.016, respectively]. A similar association was also observed for the CG genotype of CD14 rs4914 (OR= 1.69, 95% CI 1.20-2.36, P = 0.002). In addition, a combination of polymorphisms in LBP rs2232596 and CD14 rs4914 led to a 3.4-fold increased risk of CRC (OR = 3.44, 95% CI 1.94-6.10, P = 0.000).

CONCLUSION: This study highlights the LBP rs2232596 and CD14 rs4914 polymorphisms as biomarkers for elevated CRC susceptibility in the Chinese Han population.

Genetic variations in CD14 promoter and acute lymphoblastic leukemia susceptibility in a Chinese population

Recent findings suggest that CD14 may play a role in tumor development. Previous case-control studies have revealed that CD14 -260C/T and -651 C/T polymorphisms contribute to the risk of human diseases. However, the relationship between these two functional polymorphisms and susceptibility to acute lymphoblastic leukemia (ALL) has not been explored. In this study, we performed a case-control study in a Chinese population. We found that an increased risk of ALL was associated with the -260 TT (odds ratio [OR]=1.85, 95% confidence interval [CI]=1.26-2.63) genotype compared with the CT or CC genotype. No significant association was found between -651 CC genotype and ALL (OR=1.13, 95% CI=0.77-1.69). Moreover, the increased risk was only associated with the -260 TT genotype in B-ALL (OR=1.99, 95% CI=1.34-3.01) but not in T-ALL (OR=1.48, 95% CI=0.79-2.84). The findings suggest that CD14-260C/T polymorphism can contribute to B-ALL risk in a Chinese population.

Bioinformatic analyses identifies novel protein-coding pharmacogenomic markers associated with paclitaxel sensitivity in NCI60 cancer cell lines

BACKGROUND

Paclitaxel is a microtubule-stabilizing drug that has been commonly used in treating cancer. Due to genetic heterogeneity within patient populations, therapeutic response rates often vary. Here we used the NCI60 panel to identify SNPs associated with paclitaxel sensitivity. Using the panel's GI50 response data available from Developmental Therapeutics Program, cell lines were categorized as either sensitive or resistant. PLINK software was used to perform a genome-wide association analysis of the cellular response to paclitaxel with the panel's SNP-genotype data on the Affymetrix 125 k SNP array. FastSNP software helped predict each SNP's potential impact on their gene product. mRNA expression differences between sensitive and resistant cell lines was examined using data from BioGPS. Using Haploview software, we investigated for haplotypes that were more strongly associated with the cellular response to paclitaxel. Ingenuity Pathway Analysis software helped us understand how our identified genes may alter the cellular response to paclitaxel.

RESULTS

43 SNPs were found significantly associated (FDR<0.005) with paclitaxel response, with 10 belonging to protein-coding genes (CFTR, ROBO1, PTPRD, BTBD12, DCT, SNTG1, SGCD, LPHN2, GRIK1, ZNF607). SNPs in GRIK1, DCT, SGCD and CFTR were predicted to be intronic enhancers, altering gene expression, while SNPs in ZNF607 and BTBD12 cause conservative missense mutations. mRNA expression analysis supported these findings as GRIK1, DCT, SNTG1, SGCD and CFTR showed significantly (p<0.05) increased expression among sensitive cell lines. Haplotypes found in GRIK1, SGCD, ROBO1, LPHN2, and PTPRD were more strongly associated with response than their individual SNPs.

CONCLUSIONS

Our study has taken advantage of available genotypic data and its integration with drug response data obtained from the NCI60 panel. We identified 10 SNPs located within protein-coding genes that were not previously shown to be associated with paclitaxel response. As only five genes showed differential mRNA expression, the remainder would not have been detected solely based on expression data. The identified haplotypes highlight the role of utilizing SNP combinations within genomic loci of interest to improve the risk determination associated with drug response. These genetic variants represent promising biomarkers for predicting paclitaxel response and may play a significant role in the cellular response to paclitaxel.

Association and haplotype analysis of prostate stem cell antigen with gastric cancer in Tibetans

Genetic factors are known to be important in the development of gastric cancer (GC). Prostate stem cell antigen (PSCA) has been shown to be expressed in diffuse-type GC, and PSCA variation is associated with susceptibility to diffuse-type GC in Japanese and Korean populations. The aim of this study was to investigate the association between PSCA gene polymorphisms and GC in a Tibetan population. We analyzed single-nucleotide polymorphisms of the PSCA gene in 196 patients with GC and 246 controls in a Tibetan population, using a polymerase chain reaction/ligase detection reaction test. The rs2294008 C/T polymorphism of the PSCA gene was significantly associated with the susceptibility to GC. The CT genotype was associated with a significantly higher risk of GC when compared with the CC genotype (odds ratio [OR] = 1.50; 95% confidence interval [CI], 1.01-2.23). Patients carrying the T allele had a significantly higher risk for developing GC compared with individuals carrying the C allele (OR = 1.34; 95% CI, 1.00-1.79). Haplotype analyses showed that CA haplotype was associated with a significantly decreased risk of GC when compared with the CG haplotype (OR = 0.47; 95% CI, 0.24-0.93). Our data indicate that PSCA gene polymorphisms may be associated with GC in Tibetans.

-651C/T promoter polymorphism in the CD14 gene is associated with severity of acute pancreatitis in Japan

PURPOSE

This study aimed to clarify the association of the promoter variants in the CD14 gene with pancreatic diseases in Japan.

METHODS

Three hundred forty-six unrelated patients with acute pancreatitis (AP) (107 with severe and 239 with mild), 263 patients with chronic pancreatitis (CP), 264 patients with pancreatic neoplasm, and 319 healthy controls were genotyped for the single nucleotide polymorphisms at positions -260 and -651 from the AUG start codon in the CD14 gene by polymerase chain reaction-restriction enzyme digestion.

RESULTS

The allele and genotype frequencies of the -260C/T and -651C/T polymorphisms did not differ between controls and patients with AP. In subgroup analyses, patients with severe AP had more -651C allele than controls [P = 0.005; odds ratio (OR) 1.71; 95% confidence interval (CI) = 1.18-2.49] or patients with mild AP (P = 0.001; OR 1.95; 95% CI = 1.33-2.85). Genotype -651CC was more common (P = 0.001 vs. controls and P = 0.001 vs. mild AP), and -651CT was less (P = 0.009 vs. controls and P = 0.007 vs. mild AP) in patients with severe AP than in healthy controls or patients with mild AP. The frequencies of pseudocyst development and requirement of surgery were higher in AP patients with -651CC than in those without this genotype. The -260C/T polymorphism was not associated with the severity of AP. The allele and genotype frequencies of both polymorphisms did not differ between controls and patients with CP or pancreatic neoplasm.

CONCLUSION

-651C/T promoter polymorphism in the CD14 gene was associated with severity of AP in Japan.

Serum sCD14, polymorphism of CD14(-260) and periodontal infection

BACKGROUND AND AIMS

CD14 is a co-receptor involved in the recognition of Gram-negative and positive bacteria. Infections are known to influence serum sCD14 levels, and CD14 gene promoter polymorphism (CD14 C-260T) has been reported to be associated with many infectious diseases. Our aim was to investigate whether serum sCD14 concentration is associated with periodontal infection and the CD14(-260) genotype.

SUBJECTS AND METHODS

The periodontal status of 56 subjects with chronic periodontitis and 28 controls was clinically examined. Serum sCD14 concentration was analyzed using ELISA and CD14(-260) genotype using polymerase chain reaction (PCR).

RESULTS

The mean concentration of sCD14 in serum was significantly higher in subjects with periodontitis than in control subjects (4.9 microg ml(-1)vs 3.8 microg ml(-1), P < 0.001). Serum sCD14 concentration associated significantly with the extent of advanced periodontal disease. In a regression analysis including both subject groups, the CD14(-260) genotype was a significant determinant for serum sCD14 concentration. After stratification by periodontal health status (periodontitis vs controls), the influence of the CD14(-260) genotype on serum sCD14 concentration was seen only in the control group.

CONCLUSIONS

Periodontal infection is associated with the serum concentration of sCD14. Moderate to severe periodontal infection overshadows the influence of the genotype on serum sCD14 concentration.

Association between CD14 polymorphisms and serum soluble CD14 levels: effect of atopy and endotoxin inhalation

BACKGROUND

A prerequisite for activation of the innate immune response by endotoxin is its binding to CD14.

OBJECTIVE

The aim of this study was to evaluate the role of CD14 polymorphisms, atopy, and inhaled endotoxin in modulating serum CD14 levels.

METHODS

Healthy volunteers (n = 88) were genotyped for CD14 polymorphisms at the -1619, -1359, and -159 loci, relative to the transcription start site. Subjects inhaled 20 mug of endotoxin, and white blood cell, C-reactive protein, LPS-binding protein, and soluble CD14 (sCD14) levels were measured before and after exposure.

RESULTS

Homozygotes for the -1619G, -1359G, and -159T alleles had higher baseline levels of sCD14 than carriers of the CD14/-1619AA (P = .015), -1359GT/TT (P = .015), or -159CC (P = 0.017) genotypes. sCD14 levels increased within 24 hours of endotoxin inhalation (P < .0001 for all biomarkers); however, the association between CD14 polymorphisms and sCD14 levels was no longer present after exposure. The atopic status of an individual did not alter these associations. CD14 polymorphisms were not associated with levels of white blood cells, C-reactive protein, and LPS-binding protein before or after endotoxin challenge.

CONCLUSION

These data suggest that CD14 promoter polymorphisms and inhaled endotoxin modulate sCD14 levels.