Fengyan Xu

Harbin Medical University, Charbin, Heilongjiang Sheng, China

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Publications (10)34.94 Total impact

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    ABSTRACT: Various solutions are utilized widely for the isolation, harvesting, sorting, testing and transplantation of neural stem cells (NSCs), whereas the effects of harvesting media on the biological characteristics and repair potential of NSCs remain unclear. To examine some of these effects, NSCs were isolated from cortex of E14.5 mice and exposed to the conventional harvesting media [0.9% saline (Saline), phosphate-buffered saline (PBS) or artificial cerebrospinal fluid (ACSF)] or the proliferation culture medium (PCM) for different durations at 4°C. Treated NSCs were grafted by in situ injection into the lesion sites of traumatic brain injury (TBI) mice. In vitro, harvesting media-exposed NSCs displayed time-dependent reduction of viability and proliferation. S phase entry decreased in harvesting media-exposed cells, which was associated with upregulation of p53 protein and downregulation of cyclin E1 protein. Moreover, harvesting media exposure induced the necrosis and apoptosis of NSCs. The levels of Fas-L, cleaved caspase 3 and 8 were increased, which suggests that the death receptor signaling pathway is involved in the apoptosis of NSCs. In addition, exposure to Saline did not facilitate the neuronal differentiation of NSCs, suggesting that Saline exposure may be disadvantageous for neurogenesis. In vivo, NSC-mediated functional recovery in harvesting media-exposed NSC groups was notably attenuated in comparison with the PCM-exposed NSC group. In conclusion, harvesting media exposure modulates the biological characteristics and repair potential of NSCs after TBI. Our results suggest that insight of the effects of harvesting media exposure on NSCs is critical for developing strategies to assure the successful long-term engraftment of NSCs.
    Preview · Article · Sep 2014 · PLoS ONE
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    ABSTRACT: Background The interaction of tumor necrosis factor-α (TNF-α) with its receptors: TNFRSF1A and TNFRSF1B is critical for the promotion of tumor growth, invasion and metastasis. To better understand the roles of single nucleotide polymorphisms (SNPs) in the TNF-α, TNFRSF1A and TNFRSF1B genes in the development of breast cancer, we explored the associations between SNPs in these three genes and breast cancer susceptibility in northeast Chinese Han women. Methodology/Principal Findings This case-control study was conducted among 1016 breast cancer patients and 806 age-matched healthy controls. Seven SNPs in the TNF-α (rs1800629, rs361525), TNFRSF1A (rs767455, rs4149577 and rs1800693) and TNFRSF1B (rs1061622 and rs1061624) genes were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. In TNFRSF1B, the rs1061622 GT genotype and the G allele conferred a reduced susceptibility to breast cancer (P = 0.000662, OR = 0.706, 95% CI: 0.578–0.863; P = 0.002, OR = 0.769, 95% CI; 0.654–0.905, respectively). Moreover, the AG genotype, the AA genotype and the A allele in rs1061624 conferred an increased risk of breast cancer (P = 0.007, OR = 1.470, 95% CI:1.112–1.943; P = 0.00109, OR = 1.405 95% CI:1.145–1.724; P = 0.001, OR = 1.248 95% CI:1.092–1.426, respectively). These two SNPs also had associations with breast cancer risk under the dominant model. In haplotype analysis, the CTA (rs767455 C-rs4149577 T-rs1800693 A) haplotype in TNFRSF1A and the TA (rs1061622 T-rs1061624 A) haplotype in TNFRSF1B had higher frequencies in breast cancer patients (P = 0.00324; P = 0.000370, respectively), but the frequency of GG (rs1061622 G-rs1061624 G) haplotype in TNFRSF1B was lower in breast cancer patients (P = 0.000251). The associations of the three haplotypes remained significant after correcting for multiple testing. In addition, significant associations were also observed between TNFRSF1A polymorphisms and lymph node metastasis, P53, estrogen receptor (ER) and progesterone receptor (PR) statuses. Conclusions Our results suggest that rs1061622 and rs1061624 in TNFRSF1B may affect breast cancer risk, and SNPs in TNFRSF1A are associated with the clinical features of breast cancer.
    Preview · Article · Jul 2014 · PLoS ONE
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    ABSTRACT: Abstract Endogenous or graft-derived oligodendrocytes promote myelination and aid in the recovery from central nervous system (CNS) injury. Regulatory mechanisms underlying neural myelination and remyelination in response to injury, including spinal cord injury (SCI), are unclear. In the present study, we demonstrated that TROY serves as an important negative regulator of oligodendrocyte development and that TROY inhibition augments the repair potential of oligodendrocyte precursor cell (OPC) graft for SCI. TROY expression was detected by RT-PCR in OPCs as well as in differentiated premature and mature oligodendrocytes of postnatal mice. Pharmacological inhibition or RNAi-induced knockdown of TROY promotes OPC differentiation, whereas overexpression of TROY dampens oligodendrocyte maturation. Furthermore, treatment of co-cultures of DRG neurons and OPCs with TROY inhibitors promotes myelination and myelin sheath-like structures. Mechanically, protein kinase C (PKC) signaling is involved in the regulation of the inhibitory effects of TROY. Moreover, in situ transplantation of OPCs with TROY knockdown leads to notable remyelination and neurological recovery in rats with SCI. Our results indicate that TROY negatively modulates remyelination in the CNS, and thus may be a suitable target for improving the therapeutic efficacy of cell transplantation for CNS injury.
    No preview · Article · Apr 2014 · Stem cells and development
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    ABSTRACT: CD28 is one of a number of costimulatory molecules that play crucial roles in immune regulation and homeostasis. Accumulating evidence indicates that immune factors influence breast carcinogenesis. To clarify the relationships between polymorphisms in the CD28 gene and breast carcinogenesis, a case-control study was conducted in women from Heilongjiang Province in northeast of China. Our research subjects consisted of 565 female patients with sporadic breast cancer and 605 age- and sex-matched healthy controls. In total, 12 single nucleotide polymorphisms (SNPs) in the CD28 gene were successfully determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The relationship between the CD28 variants and clinical features, including histological grade, tumor size, lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2), estrogen receptor (ER), progesterone receptor (PR), and tumor protein 53 (P53) status were analyzed. A statistically significant association was observed between rs3116496 and breast cancer risk under different genetic models (additive P = 0.0164, dominant P = 0.0042). Different distributions of the rs3116496 'T' allele were found in patients and controls, which remained significant after correcting the P value for multiple testing using Haploview with 10,000 permutations (corrected P = 0.0384). In addition, significant associations were observed between rs3116487/rs3116494 (D' = 1, r(2) = 0.99) and clinicopathological features such as C-erbB2 and ER status, in breast cancer patients. Our findings indicate that CD28 gene polymorphisms contribute to sporadic breast cancer risk and have a significant association with clinicopathological features in a northeast Chinese Han population.
    Preview · Article · Oct 2012 · PLoS ONE
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    ABSTRACT: CD27 and its ligand, CD70, are major costimulatory molecules whose interaction can regulate the expansion and differentiation of effector and memory T-cell populations. Their abnormal expression can disturb the immune response and lead to an increased risk of cancer. This study aims to evaluate the associations between single nucleotide polymorphisms (SNPs) in CD27/CD70 gene and breast cancer susceptibility. Five tagSNPs and one coding polymorphism in CD27, as well as three tagSNPs in CD70, were genotyped in a case-control study of 610 breast cancer patients and 617 healthy controls. In CD27, rs3136550 CT and rs2267966 AT genotypes were associated with a decreased risk of breast cancer (P = 0.03, OR = 0.76; P = 0.02, OR = 0.75, respectively). In CD70, AG and GG genotypes in rs1862511 and CC genotype in rs2059154 also showed significant associations with a decreased risk of breast cancer (P = 2.00 × 10(-3), OR = 0.69; P = 0.03, OR = 0.62; P = 2.00 × 10(-3), OR = 0.53; respectively). Significant associations were also found in the dominant and recessive models for rs2059154 and dominant model for rs1862511. In haplotype analysis, CCGAG haplotype in CD27 and TAA haplotype in CD70 conferred an increased risk of breast cancer (P = 5.60 × 10(-3); P = 7.75 × 10(-5), respectively), but TGC, TAC and TGA haplotypes in CD70 were associated with a decreased risk of breast cancer (P = 0.01; P = 5.2 × 10(-3); P = 2.00 × 10(-3), respectively). The associations of CCGAG, TAA, TAC and TGA haplotypes remained significant after correcting P value for multiple testing. Significant associations were shown between the SNPs of CD27 and lymph node metastasis, and ER and PR statuses. These results indicate that CD27 and CD70 gene polymorphisms may affect the risk of breast cancer and show that some SNPs are associated with breast cancer characteristics in a northern Chinese population.
    No preview · Article · Mar 2012 · Breast Cancer Research and Treatment
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    ABSTRACT: Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an inhibitory molecule that plays a pivotal role in downregulating T-cell mediated immune responses. To determine the role of CTLA-4 in tumor immunity, and to validate previous results as well, we investigated four tag single nucleotide polymorphisms (SNPs) of CTLA-4 in a relatively large Chinese Han cohort from northeastern China. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 581 patients and 566 age-matched controls. Our data indicated that compared with the common genotype and allele of each SNP, the -1722 CC genotype and C allele showed an increased risk of breast cancer (P = 0.030, odds ratio (OR) = 1.457, 95% confidence internal (CI) 1.036-2.051; P = 0.024, OR = 1.214, 95% CI 1.026-1.436, respectively). The -1661 GG genotype and G allele were also associated with an increased risk of breast cancer (P = 0.018, OR = 1.396, 95% CI 1.058-1.843; P = 0.013, OR = 1.353, 95% CI 1.066-1.717, respectively). In the haplotype analysis, the CAAA haplotype showed a higher frequency in cases (P = 0.004), and this association remained significant after correcting the P value for multiple testing. Associations were shown between the SNPs of CTLA-4 and lymph node metastasis, estrogen receptor (ER), progesterone receptor (PR) and P53 statuses. These results indicate that some SNPs in the CTLA-4 gene may affect the risk of breast cancer and show that some SNPs are associated with breast cancer characteristics in Han women in northeastern China.
    No preview · Article · Jan 2012 · Molecular and Cellular Biochemistry
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    ABSTRACT: Inducible costimulator (ICOS), a costimulatory molecular of the CD28 family, provides positive signal to enhance T cell proliferation. Its abnormal expression can disturb the immune response and entail an increased risk of cancer. To investigate whether single nucleotide polymorphisms (SNPs) in the ICOS gene are associated with sporadic breast cancer susceptibility and progression in Chinese women, a case-control study was conducted. In the study cohort, we genotyped five SNPs (rs11889031, rs10932029, rs4675374, rs10183087 and rs10932037) in ICOS gene among 609 breast cancer patients and 665 age-matched healthy controls. Furthermore, the positive results were replicated in an independent validation cohort of 619 patients and 682 age-matched healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes. In rs10932029, compared with TT genotype and T allele, the CT genotype and C allele showed a significantly increased risk of breast cancer (P = 0.030, OR = 1.467, 95% CI 1.037-2.077; P = 0.017, OR = 1.481, 95% CI 1.070-2.049, respectively), and the associations were also significant in the validation cohort (P = 0.002, OR = 1.693, 95% CI 1.211-2.357; P = 0.003, OR = 1.607, 95% CI 1.171-2.204, respectively). Haplotype analysis showed that CTCAC haplotype containing rs10932029 T allele had a lower frequency in cases than in controls (P = 0.015), whereas haplotype CCCAC containing rs10932029 C allele was more common in cases than in controls (P = 0.013). In the analysis of clinicopathologic features, rs11889031 CT genotype and T allele were associated with progesterone receptor (PR) status and lymph node metastasis, which were further supported by our validation cohort. Moreover, some haplotypes were associated with estrogen receptor (ER) and PR statuses. These results indicate that ICOS gene polymorphisms may affect the risk of breast cancer and show that some SNPs are associated with breast cancer characteristics in a northern Chinese population.
    Preview · Article · Sep 2011 · BMC Cancer
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    ABSTRACT: The programmed death-1 (PD-1) is a potent immunoregulatory molecule which is responsible for the negative regulation of T-cell activation and peripheral tolerance. In order to investigate the association between polymorphisms of PD-1 and breast cancer, a case-control study was conducted in Chinese female population consisting of 490 cases with breast cancer and 512 age-matched healthy individuals from Heilongjiang Province of China. Four polymorphisms of the PD-1 gene, including rs36084323 (PD-1.1), rs7421861, rs2227982 (PD-1.9), and rs2227981 (PD-1.5), were selected and genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The frequencies of PD-1.1 GG genotype and PD-1.5 CT genotype were significantly lower in cases compared with controls (P = 0.020 and 0.004, respectively), and PD-1.5 CC genotype and C allele had higher frequencies in cases (P = 0.003 and 0.010). In haplotype analysis, we observed that the frequencies of ATTC and GTCT haplotypes were lower in cases than those of in controls (P = 0.0055 and 0.0012, respectively), whereas the GTCC and ATCC haplotypes had higher frequencies in cases (P = 0.0040 and 0.00008037, respectively). Additionally, strong association was showed between PD-1.1 and P53, and haplotype CCTA was associated with ER status. These results primarily suggest that PD-1 gene polymorphisms may affect the breast cancer risk and prognosis in Chinese Han females of Heilongjiang Province in Northeast China.
    No preview · Article · Apr 2011 · Breast Cancer Research and Treatment
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    ABSTRACT: The infiltrative duct carcinoma (IDC) is the most common malignant breast cancer in females and genetic factors appear to play a significant role in the susceptibility of IDC. The LFA-1 is a crucial co-stimulatory molecule in immune system and may affect the development of breast IDC. In order to clarify the association of LFA-1 polymorphisms with IDC, a case-control study was conducted in women from Heilongjiang Province, Northeast of China. We scrutinized four genetic polymorphisms in LFA-1 gene, which may influence the activity and function of LFA-1. Our research subjects consist of 537 cases with IDC and 577 age-matched healthy controls. Genotypes were determined by PCR-RFLP. Data were analyzed using the χ(2) test by SPSS 13.0 and Haploview 4.1 softwares. The association between LFA-1 polymorphisms and the clinical features of IDC was analyzed. In rs2230433, the frequency of GG genotype and G allele was lower in cases than in controls (P = 0.0316 and 0.0480). And rs2230433, CG genotype was higher in cases (P = 0.0397). In rs8058823, the frequency of AA genotype and A allele was lower in cases than in controls (P = 0.00000418 and 0.00000267). And rs8058823, AG genotype was higher in cases (P = 0.00000747). The frequency of haplotype CCGA was lower in patients. Significant association was shown between the four SNPs of LFA-1 gene and estrogen receptor (ER), progesterone receptor (PR), C-erbB-2, and P53 statuses. In addition, no association was found between LFA-1 gene polymorphisms and tumor size, and neither was it between LFA-1 gene polymorphisms and lymph node metastasis. Our results primarily suggested that LFA-1 gene polymorphisms may predict the sporadic breast IDC risk and prognosis factors in Chinese Han women in Heilongjiang Province.
    No preview · Article · Oct 2010 · Breast Cancer Research and Treatment
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    ABSTRACT: B and T lymphocyte attenuator (BTLA) is an immunoinhibitory receptor with the ability to deliver inhibitory signals for suppressing lymphocyte activation. To identify the influences of BTLA gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in women from northeast of China, Heilongjiang Province. We genotyped five SNPs (rs9288952, rs2931761, rs2633562, rs2705535 and rs1844089) in BTLA gene among exons and introns. Our research groups consist of 592 patients with breast cancer and 506 age/sex-matched healthy controls. Genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and polymerase chain reaction with confronting two-pair primer (PCR-CTPP) methods. Data were analyzed using the chi-square test by EXCEL, SPSS and Haploview softwares. The frequencies of BTLA rs1844089 CT and rs2705535 AG were higher in patients than in controls (P = 0.0164; P = 0.0031), and rs1844089 CC, rs2705535 GG and rs9288952 CC genotypes had lower incidences in patients than in controls (P = 0.0483; P = 0.0098; P = 0.0400). The frequency of haplotype CAAAT was significantly higher in patients (P = 0.0112). Strong association was shown between five SNPs of BTLA gene and tumor size, estrogen receptor (ER), progesterone receptor (PR), C-erbB-2 and P53 statuses. Strong association was observed between tumor size, ER, PR, P53 and the CAGAT(P = 0.012), TAAGT(P = 0.0378), CAGAT(P = 0.0013), CAAGT(P = 0.0373) and CAAAT(P = 0.0306) haplotypes. These results primarily suggested that BTLA gene polymorphisms may affect the sporadic breast cancer risk and prognosis in Chinese women in northeast of Heilongjiang Province.
    No preview · Article · Aug 2009 · Breast Cancer Research and Treatment

Publication Stats

59 Citations
34.94 Total Impact Points

Institutions

  • 2009-2014
    • Harbin Medical University
      • • Department of Anatomy
      • • Department of Immunology
      Charbin, Heilongjiang Sheng, China