Xiaonan Liu

Fourth Military Medical University, Xi’an, Liaoning, China

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Publications (8)27.23 Total impact

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    ABSTRACT: Previous studies have demonstrated that ATP citrate lyase (ACLY) plays an important role in the development of many cancers. Our current study aims to assess the effects of functional single nucleotide polymorphisms (SNPs) in ACLY gene on recurrence and survival of colorectal cancer (CRC) patients. A total of 697 resected Chinese CRC patients were included in this study. Two functional single nucleotide polymorphisms in ACLY gene were examined using the Sequenom iPLEX genotyping system. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the prognosis analysis. Multivariate Cox regression analysis showed that there was no significant association between SNPs in ACLY gene and the prognosis of total patient cohort. However, in patients with stage III + IV diseases, the two functional SNPs (rs2304497 and rs9912300) exhibited a significant association with the risks of death (HR = 0.47, 95% CI = 0.24-0.90 and HR = 0.59, 95% CI = 0.37-0.92, respectively) and recurrence (HR = 0.46, 95% CI = 0.24-0.86 and HR = 0.54, CI = 0.35-0.83, respectively). Kaplan-Meier analysis indicated that those CRC patients carrying heterozygous (WV) or homozygous variant (VV) genotypes in rs2304497 and rs9912300 had significantly better overall survival (OS) and recurrence-free survival (RFS). Moreover, we observed remarkable cumulative effects of these two SNPs on overall survival and recurrence-free survival (P for trend = 0.012 and 0.003, respectively). Compared with patients carrying zero unfavorable genotype, those carrying two unfavorable genotypes had a 2.24-fold and 2.33-fold increase of death and recurrence risks, respectively. The SNPs in ACLY gene may serve as independent prognostic markers for patients with advanced stage CRC.
    World Journal of Surgical Oncology 12/2015; 13(1):440. DOI:10.1186/s12957-015-0440-x · 1.20 Impact Factor
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    ABSTRACT: Integrin β1 (ITGB1) has been recognized to play a major role in tumor growth, invasion and metastasis. However, effects of single-nucleotide polymorphisms (SNPs) in ITGB1 gene on the prognosis of patients with colorectal cancer (CRC) have not been reported. A total of 372 patients with resected colorectal adenocarcinoma were enrolled in our study. Three functional SNPs (rs2230395, rs1187075 and rs1187076) in ITGB1 were selected and genotyped using the Sequenom iPLEX genotyping system. We identified two SNPs (rs2230395 and rs1187075) in ITGB1 gene to be significantly associated with CRC overall survival (OS). Compared with the homozygous wild-type (AA) and heterozygous variant (AC), rs2230395 homozygous variant (CC) conferred a 1.55-fold (95 % CI 1.00-2.41, P = 0.049) increased risk of death. Similar result was obtained for homozygous variant (AA) in rs1187075 with a 1.62-fold (95 % CI 1.08-2.42, P = 0.020). In stratified analysis, this association in rs2230395 remained to be significant in patients receiving chemotherapy, but not in those without chemotherapy. We further evaluated the effects of chemotherapy on CRC survival in subgroups stratified by rs2230395 and rs1187075 genotypes. We found that chemotherapy resulted in a significantly better OS in patients with the homozygous wild-type (WW) or heterozygous variant (WV) genotype in both rs2230395 and rs1187075 when compared with patients with homozygous variant (VV) genotype. Our data suggest that ITGB1 SNPs might be a prognostic biomarker for CRC patients, especially in those receiving chemotherapy. Our findings warrant validation in larger independent populations.
    Cancer Chemotherapy and Pharmacology 04/2015; DOI:10.1007/s00280-015-2745-4 · 2.57 Impact Factor
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    ABSTRACT: Compelling evidence has indicated a significant association between leukocyte mitochondrial DNA (mtDNA) content and incidence risks of several malignancies in a cancer-specific manner. However, to date, whether leukocyte mtDNA content can predict clinical outcome of cancer patients has never been investigated. In the present study, we measured leukocyte mtDNA content using real-time PCR-based method in a total of 598 colorectal cancer (CRC) patients and explored its prognostic values. To explore potential mechanism, we detected the immunophenotypes of peripheral blood mononuclear cells and plasma concentrations of several cytokines in CRC patients. We found that patients with high mtDNA content showed significantly worse overall survival (OS) and relapse-free survival (RFS) than those with low mtDNA content in all patient sets. Furthermore, mtDNA content and TNM stage exhibited a notable joint effect in prognosis prediction. Integration of TNM stage and leukocyte mtDNA content significantly improved the prognosis prediction efficacy for CRC. Importantly, patients with high mtDNA content showed OS and RFS benefits from adjuvant chemotherapy. In addition, we found that patients with high mtDNA content had a higher frequency of CD4(+)CD25(+)FOXP3(+) regulatory T cells, higher plasma IL-2 and TGF-β1 and lower TNF-α concentration than those with low mtDNA content, suggesting a stronger immunosuppressive phenotype. In conclusion, our study for the first time demonstrates that leukocyte mtDNA content is an independent prognostic marker complementing TNM stage and associated with the immunosuppression in CRC patients. Additionally, leukocyte mtDNA content might serve as a potential biomarker to select CRC patients who will benefit from adjuvant chemotherapy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Carcinogenesis 03/2015; DOI:10.1093/carcin/bgv042 · 5.27 Impact Factor
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    ABSTRACT: Previous studies have demonstrated that monocarboxylate transporters (MCTs) play important roles in the development and progression of many cancers. The purpose of this study was to assess the effects of single-nucleotide polymorphisms (SNPs) of MCT genes on prognosis of colorectal cancer (CRC) patients. Nine functional SNPs in three MCT genes (MCT1, MCT2 and MCT4) were selected and genotyped using Sequenom iPLEX genotyping system in 697 Chinese CRC patients receiving surgery. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the prognostic analysis. One SNP (MCT1: rs1049434/exon) was significantly associated with overall survival of CRC patients (HR 0.74; P = 0.046). Two other SNPs (MCT1: rs60844753/5' near gene and MCT2: rs995343/intron) exhibited associations with recurrence-free survival of CRC patients (HR 0.67; P = 0.078 and HR 0.74; P = 0.036, respectively). Our study also showed that MCT1 rs1049434, rs60844753 and MCT2 rs995343 SNPs had a cumulative effect on CRC recurrence-free survival (P for trend 0.011). Those who carrying three unfavorable genotypes (WW for all SNPs) had a 2.06-fold increased risk of recurrence compared with patients carrying no unfavorable genotypes (P = 0.016). Moreover, we found that patients carrying no <2 risk genotypes showed significant OS and RFS benefits from adjuvant chemotherapy. Our findings suggest that SNPs in MCT1 and MCT2 genes may affect clinical outcomes and can be used to predict the response to adjuvant chemotherapy in CRC patients who received surgical treatment once validated in future study.
    Journal of Cancer Research and Clinical Oncology 12/2014; DOI:10.1007/s00432-014-1877-y · 3.01 Impact Factor
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    ABSTRACT: Hypersensitivity to radiation exposure has been suggested to be a risk factor for the development of several malignancies, but not including gastric cancer. In this case-control study, radiation sensitivity as measured by chromatid breaks per cell (b/c) was examined in cultured peripheral blood lymphocytes (PBLs) from 517 patients with gastric cancer and 525 healthy controls. Our results showed that b/c values were significantly higher in cases than in controls (Mean [SD], 0.47 [0.20] vs. 0.34 [0.17]; P<0.001). Using the 50(th) percentile value for controls (0.34 b/c) as the cutoff point, unconditional logistic regression analysis revealed that γ-radiation-sensitive individuals were at significantly higher risk for gastric cancer (adjusted odds ratio [OR] 2.01, 95% confidence interval [CI] 1.49-3.13). Quartile stratification analysis indicated a dose-response relationship between γ-radiation sensitivity and gastric cancer risk (P for trend <0.001). When using the subjects in first quartile of b/c values as reference, the adjusted ORs and corresponding CIs for the subjects in second, third, and fourth quartiles were 1.48 (0.91-2.17), 2.42 (1.76-3.64), and 3.40 (2.11-5.29), respectively. The γ-radiation sensitivity was related to age and smoking status. In addition, a clear joint effect on cancer risk was found between γ-Radiation sensitivity and smoking status. The risk for ever smokers with high sensitivity was higher than those for never smokers with high sensitivity and ever smokers with low sensitivity (OR [CI], 4.67 [2.31-6.07] vs. 2.14 [1.40-3.06] vs. 2.42 [1.57-3.95], respectively). No significant interaction was found between both factors (P for interaction= 0.42). We conclude that chromatid radiosensitivity is associated with gastric cancer susceptibility in a Chinese population.
    PLoS ONE 08/2012; 7(8):e43625. DOI:10.1371/journal.pone.0043625 · 3.53 Impact Factor
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    ABSTRACT: Natural killer (NK) cells play important roles in the immune defense against tumor cells. The function of NK cells is determined by a balance between activating and inhibitory signals. DNAX accessory molecule-1 (DNAM-1) and NK group 2 member D (NKG2D) are major NK cell activating receptors, which transduce activating signals after binding their ligands CD155, CD112 and major histocompatibility complex class I-related chains A and B (MICA/B). However, the expression and functions of these ligands in colon carcinoma are still elusive. Here, we show the higher expression of CD155, CD112 and MICA/B in colon carcinoma tissues, although no correlations between the ligands expression and patient clinicopathological parameters were found. The subsequent cytotoxicity assay indicated that NK cells effectively kill colon carcinoma cells. Functional blocking of these ligands and/or receptors with antibodies led to significant inhibition of NK cell cytotoxicity. Importantly, expression of DNAM-1 and NKG2D was reduced in NK cells of colon cancer patients, and this reduction could directly suppress the activation of NK cells. Moreover, colon cancer patients have higher serum concentrations of sCD155 and sMICA/B (soluble ligands, secreted or shed from cells) than those in healthy donors (sCD155, 127.82 ± 44.12 vs. 63.67 ± 22.30 ng/ml; sMICA, 331.51 ± 65.23 vs. 246.74 ± 20.76 pg/ml; and sMICB, 349.42 ± 81.69 vs. 52.61 ± 17.56 pg/ml). The up-regulation of these soluble ligands may down-regulate DNAM-1 and NKG2D on NK cells, ultimately leading to the inhibition of NK cytotoxicity. Colon cancer might be a promising target for NK cell-based adoptive immunotherapy.
    The Tohoku Journal of Experimental Medicine 01/2012; 226(1):59-68. DOI:10.1620/tjem.226.59 · 1.28 Impact Factor
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    ABSTRACT: Compelling epidemiological evidence indicated that alterations of mitochondrial DNA (mtDNA), including mutations and abnormal content of mtDNA, were implicated in the tumorigenesis of several malignancies in a tumor-specific manner, such as lung cancer, breast cancer, and non-Hodgkin lymphoma. This study was undertaken to investigate whether mtDNA content in peripheral blood lymphocytes (PBLs) could be used as a risk predictor for colorectal cancer (CRC). The mtDNA content was measured by using quantitative real-time polymerase chain reaction in PBLs from 320 CRC patients and 320 matched controls. The authors found that CRC patients exhibited statistically significantly higher mtDNA content than matched controls (median, 1.03 vs .86; P < .001). They further assessed the association between mtDNA content and CRC risk using multivariate logistic regression. By using the median value in controls as the cutoff point, they found that, compared with low mtDNA content, high mtDNA content was associated with a significantly increased CRC risk (adjusted odds ratio, 2.03; 95% confidence interval, 1.41-2.81). In a trend analysis, they found a statistically significant dose-response relationship between higher mtDNA content and increased CRC risk (P for trend <.001). Stratified analysis showed that the association between mtDNA content and CRC risk was not modulated by major host characteristics. These findings provide the first epidemiological evidence linking the high mtDNA content in PBLs to elevated CRC risk.
    Cancer 07/2011; 117(14):3148-55. DOI:10.1002/cncr.25906 · 4.90 Impact Factor
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    ABSTRACT: Traditional research modes aim to find cancer-specific single therapeutic target. Recently, emerging evidence suggested that some micro-RNAs (miRNA) can function as oncogenes or tumor suppressors. miRNAs are single-stranded, small noncoding RNA genes that can regulate hundreds of downstream target genes. In this study, we evaluated the miRNA expression patterns in gastric carcinoma and the specific role of miR-223 in gastric cancer metastasis. miRNA expression signature was first analyzed by real-time PCR on 10 paired gastric carcinomas and confirmed in another 20 paired gastric carcinoma tissues. With the 2-fold expression difference as a cutoff level, we identified 22 differential expressed mature miRNAs. Sixteen miRNAs were upregulated in gastric carcinoma, including miR-223, miR-21, miR-23b, miR-222, miR-25, miR-23a, miR-221, miR-107, miR-103, miR-99a, miR-100, miR-125b, miR-92, miR-146a, miR-214 and miR-191, and six miRNAs were downregulated in gastric carcinoma, including let-7a, miR-126, miR-210, miR-181b, miR-197, and miR-30aa-5p. After examining these miRNAs in several human gastric originated cell lines, we found that miR-223 is overexpressed only in metastatic gastric cancer cells and stimulated nonmetastatic gastric cancer cells migration and invasion. Mechanistically, miR-223, induced by the transcription factor Twist, posttranscriptionally downregulates EPB41L3 expression by directly targeting its 3'-untranslated regions. Significantly, overexpression of miR-223 in primary gastric carcinomas is associated with poor metastasis-free survival. These findings indicate a new regulatory mode, namely, specific miRNA, which is activated by its upstream transcription factor, could suppress its direct targets and lead to tumor invasion and metastasis.
    Molecular Cancer Research 05/2011; 9(7):824-33. DOI:10.1158/1541-7786.MCR-10-0529 · 4.50 Impact Factor
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    ABSTRACT: The shortening of telomeres may result in chromosome instability and thus promote tumorigenesis. Previous studies have demonstrated clear involvement of telomere shortening in the carcinogenesis of several malignancies. However, the association between constitutive telomere shortening and gastric cancer development has yet to be established. Therefore, in the present study, we measured average telomere length using quantitative real-time PCR in peripheral blood lymphocytes from a gastric cancer (GC) case-control study consisting of 396 cases and 378 controls. The results showed that GC patients had significantly shorter average telomere length than matched controls (mean +/- SD 0.89 +/- 0.19 vs 1.06 +/- 0.25, P < 0.001). We further categorized telomere length using the 50% value in the controls as a cut-off point and assessed the association between telomere length and GC risk using multivariate logistic regression analysis. We found that short telomere length was associated with a significantly increased GC risk (adjusted odds ratio = 2.14, 95% confidence interval = 1.52-2.93). Quartile stratification revealed a dose-response relationship between telomere shortening and GC risk (P for trend < 0.001). Stratified analysis showed that sex, age, and alcohol drinking, but not smoking and Helicobacter pylori infection, seem to have a modulating effect on the average telomere length in both cases and controls. We also found that telomere shortening and smoking had a significant joint effect on GC risk. Collectively, our findings provide the first evidence linking the short telomere length in peripheral blood lymphocytes to elevated GC risk, which warrants further investigation in other populations.
    Cancer Science 04/2009; 100(7):1300-5. DOI:10.1111/j.1349-7006.2009.01169.x · 3.53 Impact Factor