Zhen Liu

Guangzhou Medical University, Shengcheng, Guangdong, China

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Publications (29)76.69 Total impact

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    ABSTRACT: HDGF is overexpressed in gliomas as compared to normal brain. We therefore analyzed the molecular mechanisms of HDGF action in gliomas. HDGF was downregulated in normal brain tissue as compared to glioma specimens at both the mRNA and the protein levels. In glioma samples, increased HDGF expression was associated with disease progression. Knocking down HDGF expression not only significantly decreased cellular proliferation, migration, invasion, and tumorigenesis, but also markedly enhanced TMZ-induced cytotoxicity and apoptosis in glioma cells. Mechanistic analyses revealed that CCND1, c-myc, and TGF-β were downregulated after stable HDGF knockdown in the U251 and U87 glioma cells. HDGF knockdown restored E-cadherin expression and suppressed mesenchymal cell markers such as vimentin, β-catenin, and N-cadherin. The expression of cleaved caspase-3 increased, while Bcl-2 decreased in each cell line following treatment with shHDGF and TMZ, as compared to TMZ alone. Furthermore, RNAi-based knockdown study revealed that HDGF is probably involved in the activation of both the PI3K/Akt and the TGF-β signaling pathways. Together, our data suggested that HDGF regulates glioma cell growth, apoptosis and epithelial-mesenchymal transition (EMT) probably through the Akt and the TGF-β signaling pathways. These results provide evidence that targeting HDGF or its downstream targets may lead to novel therapies for gliomas.
    Journal of Neuro-Oncology 07/2014; · 3.12 Impact Factor
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    ABSTRACT: We previously reported and revised the nasopharyngeal epithelium specific protein CCDC19 and identified it as a potential tumour suppressor in nasopharyngeal carcinoma. The purpose of this study was to investigate the involvement of CCDC19 in the pathogenesis of human non-small cell lung cancers (NSCLC). Down-regulated CCDC19 expression was observed in NSCLC tissues and cells compared to normal tissues. However, reduced protein expression did not correlate with the status of NSCLC progression. Instead, we observed that patients with lower CCDC19 expression had a shorter overall survival than did patients with higher CCDC19 expression. Lentiviral-mediated CCDC19 overexpression significantly suppressed cell proliferation and cell cycle transition from G1 to S and G2 phases in NSCLC cells. Knocking down CCDC19 expression significantly restored the ability of cell growth in CCDC19 overexpressing NSCLC cells. Mechanistically CCDC19 functions as a potential tumour suppressor by stimulating miR-184 suppression of C-Myc thus blocking cell growth mediated by the PI3K/AKT/C-Jun pathway. Our studies are the first to demonstrate that reduced expression of CCDC19 is an unfavourable factor in NSCLC.
    Journal of Cellular and Molecular Medicine 06/2014; · 4.75 Impact Factor
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    ABSTRACT: CDK4 is a protein kinase in the CDK family important for G1/S phase cell cycle progression. However, the roles and molecular mechanisms of CDK4 triggering nasopharynx carcinogenesis are still unclear. Lentiviral-vector mediated shRNA was used to suppress CDK4 expression and examine its molecular mechanisms. Using immunohistochemistry, we analyzed CDK4 protein expression in clinicopathologically characterized nasopharyngeal carcinoma (NPC) cases and nasopharyngeal tissues (NPs). Survival curves were plotted by the Kaplan-Meier method and compared using the log-rank test. In this investigation, we knocked down CDK4 expression and observed that NPC cell growth and cell cycle progression were significantly blocked by suppressing expression of CCND1, CDK6, and E2F1 as well as elevated p21 expression. Further, we found that reduced CDK4 expression elevated the expression of let-7c, a tumor-suppressive miRNA modulated by E2F1. We found that let-7c was markedly downregulated in NPC tissues compared to NPs and suppressed cell growth and cell cycle progression by modulating p15/p16/CDK4/E2F1 pathway. Finally, CDK4 protein was observed to be overexpressed in NPC tissues and could be considered an unfavorable prognosis factor for NPC patients although its independent prognostic value did not reach statistical significance (p = 0.087). Our results demonstrated that overexpressed CDK4 is an unfavorable prognostic factor which suppresses the expression of tumor suppressive-factor let-7c through p21/CCND1/CDK6/E2F1 signaling, and inhibits cell proliferation by p15/p16/CDK4/E2F1 feedback signaling in NPC.
    BMC Cancer 04/2014; 14(1):274. · 3.33 Impact Factor
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    ABSTRACT: The success of using glycolytic inhibitors for cancer treatment relies on better understanding the roles of each frequently deregulated glycolytic genes in cancer. This report analyzed the involvement of a key glycolytic enzyme, alpha-enolase (ENO1), in tumor progression and prognosis of human glioma. ENO1 expression levels were examined in glioma tissues and normal brain (NB) tissues. The molecular mechanisms of ENO1 expression and its effects on cell growth, migration and invasion were also explored by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, Transwell chamber assay, Boyden chamber assay, Western blot and in vivo tumorigenesis in nude mice. ENO1 mRNA and protein levels were upregulated in glioma tissues compared to NB. In addition, increased ENO1 was associated disease progression in glioma samples. Knocking down ENO1 expression not only significantly decreased cell proliferation, but also markedly inhibited cell migration and invasion as well as in vivo tumorigenesis. Mechanistic analyses revealed that Cyclin D1, Cyclin E1, pRb, and NF-kappaB were downregulated after stable ENO1 knockdown in glioma U251 and U87 cells. Conversely, knockdown of ENO1 resulted in restoration of E-cadherin expression and suppression of mesenchymal cell markers, such as Vimentin, Snail, N-Cadherin, beta-Catenin and Slug. Furthermore, ENO1 suppression inactivated PI3K/Akt pathway regulating the cell growth and epithelial-mesenchymal transition (EMT) progression. Overexpression of ENO1 is associated with glioma progression. Knockdown of ENO1 expression led to suppressed cell growth, migration and invasion progression by inactivating the PI3K/Akt pathway in glioma cells.
    Molecular Cancer 03/2014; 13(1):65. · 5.13 Impact Factor
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    ABSTRACT: To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis. Real-time PCR and immunohistochemistry were used to examine the mRNA and protein expressions of p27 in NPC and nasopharyngeal tissues. The relationship of p27 expression levels with clinical features and prognosis of NPC patients was analyzed. The expression level of p27 mRNA was markedly lower in NPC tissues than that in the nasopharyngeal tissues (P = 0.0006). Specific p27 protein staining by immunohistochemistry was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells but decreased expression was observed in NPC samples compared to normal epithelium samples (P = 0.002). In addition, low levels of p27 protein were inversely correlated with the status of T classification (p = 0.002) and clinical stage (p = 0.019) of NPC patients. Patients with lower p27 expression had a significantly shorter overall survival time than did patients with high p27 expression. Multivariate analysis suggested that the level of p27 expression was not an independent prognostic indicator (p = 0.682) for NPC survival. Low level of p27 expression is a potential unfavorable prognostic factor for patients with NPC.Virtual slides: The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1915282782109343.
    Diagnostic Pathology 12/2013; 8(1):212. · 1.85 Impact Factor
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    ABSTRACT: The purpose of this study is to examine the correlation between nuclear expression of Cyclin-dependent kinase 4(CDK4) and clinicopathologic data in nasopharyngeal carcinoma (NPC), including patient survival. Using real-time PCR and immunohistochemistry, the expression of CDK4 was examined in NPC and nasopharyngeal(NP) tissues. We observed that mRNA expression of CDK4 was significantly elevated in NPC tissues compared to NP tissues. Further, we found that CDK4 protein was expressed in both the nucleus and cytoplasm. Nuclear expression of CDK4 was positively correlated with clinical stage (p=0.048), but not associated with other clinical features. Patients with nuclear expression of CDK4 had poorer overall survival rates than those without nuclear expression of CDK4. Further, we also found that nuclear expression of CDK4 was inversely associated with survival time of NPC patients not only in T1-2 classification, N2-3 classification, and clinical stage III-IV but also in the treatment of radiotherapy and chemotherapy. Finally, we discovered that nuclear expression of CDK4 was an independent and unfavorable prognostic factor for patients with NPC. Our findings suggest that nuclear expression of CDK4 is a potential unfavorable factor for the progression and poor prognosis of NPC. This article is protected by copyright. All rights reserved.
    Histopathology 10/2013; · 2.86 Impact Factor
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    ABSTRACT: AIMS: To examine, in nasopharyngeal carcinoma (NPC), the correlation of Krüppel-like factor 4 (KLF4) expression with clinicopathological features including patient prognosis. METHODS AND RESULTS: Using real-time PCR and immunohistochemistry, expression of KLF4 mRNA and protein was examined in NPC and nasopharyngeal tissues. The relationship of KLF4 expression levels with clinical features and prognosis of NPC patients was analysed. mRNA expression was markedly lower in NPC than in the nasopharyngeal tissues. Using immunohistochemistry, staining for KLF4 protein was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells, but decreased cytoplasmic expression was observed in atypical hyperplasia and NPC samples compared to normal and squamous epithelium samples (P < 0.001). In addition, levels of cytoplasmic KLF4 protein were correlated inversely with the nodal (N) status (TNM classification; P = 0.002) and overall clinical stage (P < 0.001) of NPC patients. Patients with NPC showing lower cytoplasmic KLF4 expression had a significantly shorter overall survival time than those with high NPC KLF4 expression. Multivariate analysis suggested that the level of KLF4 expression was an independent prognostic indicator (P = 0.008) for NPC survival. CONCLUSION: Low levels of cytoplasmic KLF4 expression are a potentially unfavourable prognostic factor for patients with NPC.
    Histopathology 04/2013; · 2.86 Impact Factor
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    ABSTRACT: Programmed cell death 4 (PDCD4), a novel tumor suppressor, inhibits cell proliferation, migration and invasion as well as promotes cell apoptosis in tumors. However, the molecular mechanism of its tumor-suppressive function remains largely unknown in tumors including nasopharyngeal carcinoma (NPC). In this study, downregulated PDCD4 expression was significantly associated with the status of NPC progression and poor prognosis. PDCD4 markedly suppressed the ability of cell proliferation and cell survival by modulating C-MYC-controlled cell cycle and BCL-2-mediated mitochondrion apoptosis resistance signals, and oncogenic transcription factor C-JUN in NPC. Furthermore, miR-184, a tumor-suppressive miRNA modulated by PDCD4 directly targeting BCL2 and C-MYC, participated in PDCD4-mediated suppression of cell proliferation and survival in NPC. Further, we found that PDCD4 decreased the binding of C-Jun to the AP-1 element on the miR-184 promoter regions by PI3K/AKT/JNK/C-Jun pathway and stimulated miR-184 expression. In clinical fresh specimens, reduced PDCD4 mRNA level was positively correlated with miR-184 expression in NPC. Our studies are the first to demonstrate that PDCD4 as tumor suppressor regulated miR-184-mediated direct targeting of BCL2 and C-MYC via PI3K/AKT and JNK/C-Jun pathway attenuating cell proliferation and survival in NPC.
    Cell Death & Disease 01/2013; 4:e872. · 6.04 Impact Factor
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    ABSTRACT: The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC). CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored. NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC. Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.
    PLoS ONE 01/2013; 8(6):e64976. · 3.73 Impact Factor
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    ABSTRACT: The purpose of the present study is to explore the correlation between nuclear expression of cyclin-dependent kinase inhibitor 1B (p27) and clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient survival. Immunohistochemistry was used to examine the expression of p27 in 130 primary NPC tissues. The relationship between the levels of p27 expression and clinicopathologic characteristics was analyzed. Survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. The significance of various survival variables was analyzed using multivariate Cox proportional hazards model. p27 was expressed in both nuclear and cytoplasmic compartments. Nuclear expression of p27 was inversely correlated with T classification and clinical stage. Patients with nuclear p27 expression had better overall survival rates than those without nuclear expression of p27. Further, we observed that nuclear expression of p27 was positively associated with survival time of NPC patients not only in N0-1 and M0 classifications but also in radiotherapy and chemotherapy treatment groups. Finally, we found that nuclear expression of p27 was not an independent prognostic factor for patients with NPC. Our findings hint that nuclear expression of p27 is a potentially favorable factor in the progression and prognosis of NPC.
    Disease markers 01/2013; 35(6):925-32. · 2.14 Impact Factor
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    ABSTRACT: To evaluate the correlation of CDK4 protein expression in the cytoplasm with the clinicopathologic features and prognosis of lung cancer. Immunohistochemistry was employed to examine CDK4 protein expression in the cytoplasm of lung cancer samples, using normal lung tissue samples as control. The correlation of cytoplasmic CDK4 protein expression with the clinicopathologic parameters and prognosis of lung cancer patients was analyzed. No significant difference was found in cytoplasmic CDK4 protein expression levels between lung cancer and normal lung tissues (P=1.000). In the lung cancer tissues, however, an increased cytoplasmic expression of CDK4 was positively correlated with the clinical stages and lymph node metastasis. Prognostic analysis showed that the patients with an increased cytoplasmic CDK4 expression had a markedly shorter overall survival than those with a low cytoplasmic CDK4 expression. Multivariate analysis suggested that the level of cytoplasmic CDK4 expression was an independent prognostic indicator for the survival of patients with lung cancer (P<0.001). Overexpression of CDK4 protein in the cytoplasm may promote the carcinogenesis of lung cancer and can be an unfavorable prognostic factor for the survival of lung cancer patients.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 11/2012; 32(11):1572-5.
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    ABSTRACT: We previously defined the recently revised NESG1 gene as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). Here, we further used proteomics technology to globally examine NESG1-controlled proteins in NPC cells. Twenty-six proteins were found to be deregulated by NESG1 using proteomics analysis while enolase 1 (alpha) (ENO1), heat shock protein 90 kDa beta (Grp94), member 1 (HSP90B1), and cathepsin D (CTSD) proteins were differentially expressed by Western blot. Interestingly, a-enolase (ENO1), an overexpressed gene in NPC, was confirmed as a NESG1-regulated protein in NPC cells. Overexpressed ENO1 not only restored cell proliferation and cell-cycle progression, but also antagonized the regulation of NESG1 to cell-cycle regulators p21 and CCNA1 expression as well as induced the expression of C-Myc, pRB, and E2F1 in NESG1-ovexpressed NPC cells. Real-time PCR and immunohistochemistry analysis showed that NESG1 expression is negatively correlated with ENO1 expression in NPC tissues. Our observations suggest that ENO1 downregulation plays an important role in NESG1-induced growth inhibition of NPC cancer cells.
    Proteomics 09/2012; · 4.43 Impact Factor
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    ABSTRACT: To screen the proteins under regulation by the candidate tumor suppressor gene CCDC19 using proteomics technology in nasopharyngeal carcinoma (NPC). The cellular proteins were extracted from 3D8 NPC cells with CCDC19 overexpression and the control C6 NPC cells. Two-dimensional (2D) gel electrophoresis was employed to compare the protein expression profiles between these two cells, and the differential proteins were identified using peptide mass fingerprinting and database searching. Real-time PCR and Western blotting were used to validate the expression levels of the differential proteins. Matrix-assisted laser desorption/time of flight showed that 3 differential proteins, namely FASN, CTSD and PGK1, were down-regulated by -3.28, -1.64, and -6.97 folds, respectively, which were confirmed by real-time PCR and Western blotting. FASN, CTSD and PGK1 are probably the target proteins regulated by CCDC19 in NPC.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 08/2012; 32(8):1127-30.
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    ABSTRACT: To explore the expression of CASP8 and its clinical significance in nasopharyngeal carcinoma (NPC). The differentially expressed genes between pooled NPC tissues and non-cancerous nasopharyngeal (NP) tissues were screened using 8 microarrays. Real-time PCR and immunohistochemistry were used to validate the detection results of CASP8 expression in NPC, and the correlation of CASP8 expression to the clinical characteristics was analyzed in the NPC cases. Real-time PCR confirmed a reduced expression of CASP8 mRNA level in NPC tissues (P<0.0001), which was consistent with the microarray data. Immunohistochemistry indicated that CASP8 protein expression was also significantly down-regulated in NPC tissue compared to that in the non-cancerous nasopharyngeal tissues (P=0.02). The reduction of CASP8 expression was inversely correlated to lymph node metastasis (P=0.002) and the clinical stages (P=0.026) of NPC. Decreased CASP8 expression is an unfavorable factor that promotes the development and progression of NPC.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 07/2012; 32(7):963-5, 969.
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    ABSTRACT: The aim of the present study was to analyze the expression of DNA-binding protein inhibitor 2 (ID2) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. It was found that the expression of ID2 was significantly increased in NPC cells when compared with that in NP69 cell line. Similar level of ID2 cytoplasmic expression was observed in NPC when compared with that in non-cancerous nasopharynx tissues. However, the level of ID2 in nucleus was increased in NPC when compared with that in normal nasopharynx tissues. Furthermore, the higher expression level of nuclear ID2 was significantly associated with tumor size (T classification), lymph node metastasis (N classification), and clinical stage. Patients with increased ID2 expression level had poorer overall survival rates than those with low ID2 levels. The inhibition of ID2 expression in NPC cell line SUNE1 by lentiviral-mediated short hairpin RNA could suppress cell proliferation and colony formation, but did not disrupt cell migration. Knocking down the expression of ID2 by RNA interference could down-regulate the expression of Snail, suggesting that ID2-promoted cell growth, partially attributing to the regulation of Snail activity in NPC. Our study demonstrated that over-expression of ID2 protein is an unfavorable prognostic factor which promotes cell proliferation in NPC.
    Acta Biochimica et Biophysica Sinica 05/2012; 44(6):503-12. · 1.81 Impact Factor
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    ABSTRACT: The aim of the present study was to analyze the expression of matrix metalloproteinase-9 (MMP9) in endometrial cancer and its correlation with clinicopathologic features in Chinese patients, including the survival of patients with endometrial cancer. Using immunohistochemistry analysis, we analyzed MMP9 protein expression in clinicopathologically characterized 128 endometrial cancer (EC) cases with age ranging from 30 to 85 years (median=51.6 years) and 30 endometrial atypical hyperplasia (EAH) and 30 normal endometrium (NE). Cases with greater than or equal to 6 and less than 6 with the score value of cytoplasmic MMP9 immunostaining were regarded as high expression and low expression, respectively. The relationship between the expression levels of MMP9 and clinical features was analyzed in EC cases. Immunohistochemical analysis revealed that the protein expression of MMP9 detected in EC tissues was higher than that in the EAH tissues and NE tissues (P=0.006). In addition, high levels of MMP9 protein were positively correlated with the status of lymph node metastasis (P=0.044) and the histopathological grade (P<0.05) of EC patients. Patients with higher MMP9 expression did not correlate with EC patients' clinical outcome in China. Multivariate analysis suggested that status of lymph node metastasis and depth of myometrial invasion, but not MMP9 expression level, were significantly correlated with patients' survival. MMP9 is highly expressed in ECs and correlates with the progression of ECs, but not be helpful in predicting the prognosis of EC patients.
    Disease markers 01/2012; 32(5):321-7. · 2.14 Impact Factor
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    ABSTRACT: The aim of the present study was to analyze the expression of Zinc finger E-box Binding homeobox 2 (ZEB2) in glioma and to explore the molecular mechanisms of ZEB2 that regulate cell proliferation, migration, invasion, and apoptosis. Expression of ZEB2 in 90 clinicopathologically characterized glioma patients was analyzed by immunohistochemistry. Furthermore, siRNA targeting ZEB2 was transfected into U251 and U87 glioma cell lines in vitro and proliferation, migration, invasion, and apoptosis were examined separately by MTT assay, Transwell chamber assay, flow cytometry, and western blot. The expression level of ZEB2 protein was significantly increased in glioma tissues compared to normal brain tissues (P<0.001). In addition, high levels of ZEB2 protein were positively correlated with pathology grade classification (P = 0.024) of glioma patients. Knockdown of ZEB2 by siRNA suppressed cell proliferation, migration and invasion, as well as induced cell apoptosis in glioma cells. Furthermore, ZEB2 downregulation was accompanied by decreased expression of CDK4/6, Cyclin D1, Cyclin E, E2F1, and c-myc, while p15 and p21 were upregulated. Lowered expression of ZEB2 enhanced E-cadherin levels but also inhibited β-Catenin, Vimentin, N-cadherin, and Snail expression. Several apoptosis-related regulators such as Caspase-3, Caspase-6, Caspase-9, and Cleaved-PARP were activated while PARP was inhibited after ZEB2 siRNA treatment. Overexpression of ZEB2 is an unfavorable factor that may facilitate glioma progression. Knockdown ZEB2 expression by siRNA suppressed cell proliferation, migration, invasion and promoted cell apoptosis in glioma cells.
    PLoS ONE 01/2012; 7(6):e38842. · 3.73 Impact Factor
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    ABSTRACT: Human NESG1 (CCDC19) gene was originally isolated in our laboratory from human nasopharynx tissue. However, the biological and clinical significances of this gene remain largely unknown. In this report, two errors in the originally submitted sequence of human NESG1 gene were found, and the open reading frame sequence of NESG1 (Accession number: NM_012337.1) was revised and updated in the NCBI database (Accession number: NM_012337.2). The antibody raised against the revised sequence of NESG1 detected a single band of 66 kD in human nasopharynx tissues. NESG1 transcripts were specifically expressed in the nasopharynx epithelium. Expression of NESG1 transcripts and protein was downregulated or absent in nasopharyngeal carcinoma (NPC) tissues and cell lines in comparison to that in the normal nasopharynx tissues. The levels of NESG1 protein were significantly greater in the low-grade NPC tissues than that in the high-grade NPC tissues. Induced expression of NESG1 in otherwise NESG1-negative 5-8F cells not only significantly decreased cell proliferation, G1-S phase transition, but also markedly inhibited the ability of cell migration and invasion as well as in vivo tumorigenesis. Furthermore, NESG1 also significantly regulated the expression of cell cycle regulator CCNA1 and p21. Our findings first provided evidence that NESG1 may act as a tumor suppressor by inhibiting cell proliferation, invasion and migration of NPC cells.
    International Journal of Cancer 06/2011; 128(11):2562-71. · 6.20 Impact Factor
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    ABSTRACT: To construct a lentiviral vector carrying human NESG1-EGFP gene and observe its expression in 293FT cells. The CDS region of NESG1 gene was amplified from a plasmid containing the full-length NESG1 sequence and cloned into the lentiviral vector pGC-FU-EGFP by restriction endonuclease AgeI digestion and T(4) DNA ligase ligation. After transformation into competent E. coli cells, the candidate clones were identified by PCR and sequencing. The recombinant plasmid and the two packaging plasmids were co-transfected into human embryonic kidney cell line 293FT cells by lipofectamine 2000 to produce the lentiviral particles, and the viral titer was determined. The 293FT cells were infected by the lentiviral particles obtained and the transfection efficiency was assessed under fluorescent microscope. Western blotting was used to detect the expression of NESG1 protein in the transfected cells. The lentiviral vector pGC-FU-NESG1-EGFP for NESG1 gene was constructed successfully. Strong green fluorescence was observed in 293FT cells under fluorescent microscope after co-transfection of the cells with the 3 plasmids of lentiviral vector. The virus in the supernatant reached a titer of 2×10(7) TU/ml. The transfection efficiency of the collected virus exceeded 90% in 293FT cells with a multiplicity of infection of 1. Western blotting identified the presence of NESG1 expression in the transfected 293FT cells. The lentiviral vector for NESG1 has been successfully constructed with a high yield of lentivirus, which facilitate further investigation of the roles of NESG1 gene in the development and progression of nasopharyngeal carcinoma.
    Nan fang yi ke da xue xue bao = Journal of Southern Medical University 01/2011; 31(1):65-8.
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    ABSTRACT: The aim of the present study was to analyze the expression of Cyclin-dependent kinase 4 (CDK4) in lung cancer and its correlation with clinicopathologic features. Furthermore, the involvement of CDK4-mediated cell cycle progression and its molecular basis were investigated in the pathogenesis of lung cancer. Using immunohistochemistry analysis, we analyzed CDK4 protein expression in 89 clinicopathologically characterized lung cancer patients (59 males and 30 females) with ages ranging from 36 to 78 years and compared them to 23 normal lung tissues. Cases with cytoplasmic and nuclear CDK4 immunostaining score values greater than or equal to 7 were regarded as high expression while scores less than 7 were considered low expression. The correlation between the expression level of CDK4 and clinical features was analyzed. Furthermore, we used lentiviral-mediated shRNA to suppress the expression of CDK4 and investigate its function and molecular mechanism for mediating cell cycle progression. The expression level of CDK4 protein was significantly increased in lung cancer tissues compared to normal tissues (P < 0.001). In addition, high levels of CDK4 protein were positively correlated with the status of pathology classification (P = 0.047), lymph node metastasis (P = 0.007), and clinical stage (P = 0.004) of lung cancer patients. Patients with higher CDK4 expression had a markedly shorter overall survival time than patients with low CDK4 expression. Multivariate analysis suggested the level of CDK4 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with lung cancer. Use of lentiviral-mediated shRNA to inhibit the expression of CDK4 in lung cancer cell line A549 not only inhibited cell cycle progression, but also dramatically suppressed cell proliferation, colony formation, and migration. Furthermore, suppressing CDK4 expression also significantly elevated the expression of cell cycle regulator p21 Overexpressed CDK4 is a potential unfavorable prognostic factor and mediates cell cycle progression by regulating the expression of p21 in lung cancer.
    Journal of Translational Medicine 01/2011; 9:38. · 3.46 Impact Factor

Publication Stats

206 Citations
76.69 Total Impact Points

Institutions

  • 2011–2014
    • Guangzhou Medical University
      Shengcheng, Guangdong, China
  • 2013
    • Guangdong Medical College
      Shengcheng, Guangdong, China
  • 2007–2013
    • Southern Medical University
      • Institute of Cancer Research
      Shengcheng, Guangdong, China
  • 2012
    • Nanfang Hospital
      Shengcheng, Guangdong, China
  • 2010
    • Cancer Research Institute
      New York City, New York, United States