Chao-Nan Qian

Sun Yat-Sen University Cancer Center, Shengcheng, Guangdong, China

Are you Chao-Nan Qian?

Claim your profile

Publications (85)441.97 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate the prognostic significance and various classifications for anatomic masticator space involvement (MSI) in patients with nasopharyngeal carcinoma (NPC).
    BMC Cancer 09/2014; 14(1):653. · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The survival outcomes of patients with metastatic nasopharyngeal carcinoma (NPC) differ significantly between individuals. Serum lipids and lipoproteins have been reported to be associated with prognosis in some cancers, but it has not been studied in metastatic NPC. The aim of this study was to evaluate whether serum lipid and lipoproteins could predict the prognosis of metastatic NPC patients. Eight hundred and seven patients with metastatic NPC were analyzed retrospectively, and the values of serum lipids and lipoproteins at baseline were retrieved. Receiver operating characteristic curve analysis and univariate and multivariate Cox proportional hazards analyses were used to evaluate the associations of serum lipids and lipoproteins with overall survival (OS). Univariate analysis revealed that higher values of baseline cholesterol (≥4.655 mmol/L), baseline high-density lipoprotein cholesterol (≥0.965 mmol/L), and baseline apolipoprotein A-I (ApoA-I) (≥1.065 g/L) were significantly associated with superior OS (p < 0.001), respectively. Multivariate Cox proportional hazard analysis showed that higher ApoA-I level (vs. lower ApoA-I level, HR 0.64, 95 % CI 0.52-0.80, p < 0.001) was an independent protective factor against progression. In addition, higher body mass index, earlier N stages, single lesion, and absence of liver metastasis were also revealed to be independent protective factors. In conclusion, the elevated baseline ApoA-I level may predict those patients likely to have a favorable OS.
    Medical oncology (Northwood, London, England). 08/2014; 31(8):80.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We aimed to determine the prognostic values of 39 circulating cytokines in Chinese patients with metastatic colorectal cancer (CRC) and to develop a novel cytokine-based prognostic classifier (CBPC) for prognostic prediction. A total of 176 patients were divided into two cohorts based on the date of first-line chemotherapy. The first 99 cases were assigned to the training cohort, and the remaining 77 cases were assigned to the validation cohort. Thirty-nine cytokines were simultaneously analyzed in the patient serum samples using multiplex bead-based Luminex technology. We used support vector machine (SVM)-based methods and Cox proportional hazards models to develop a CBPC from the training cohort, which we then validated using the second patient cohort. Univariate analysis showed that FGF-2, TGFα, Flt-3L, GM-CSF, INFα2, GRO, IL-10, MCP-3, MDC, sIL-2Rα, IL-2, IL-7, IL-8, MCP-1, MIP-1β, TNFα, and VEGF were significant risk factors affecting the overall survival (OS) of both the training cohort and the validation cohort. We developed a CBPC to predict the OS of metastatic CRC patients using these 17 cytokines (sensitivity, 0.835; specificity, 0.800). In the validation cohort, the CBPC was found to have significant power in predicting the OS of metastatic CRC patients. Our study showed that there were significant associations between cytokine expression and prognosis of the patients with metastatic CRC. The CBPC that we developed includes multiple circulating cytokines and may serve as a novel screening tool for identifying metastatic CRC patients with a high risk of short OS. These high-risk individuals may also be suitable for cytokine-targeted therapies. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 06/2014; · 6.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in southern China and Southeast Asia, with the highest metastasis rate among head and neck cancers. The mechanisms underlying NPC progression remain poorly understood. Genome-wide expression profiling on 18 NPC vs. 18 noncancerous nasopharyngeal tissues together with GeneGo pathway analysis and expression verification in NPC cells and tissues revealed a potential role of urokinase-type plasminogen activator receptor (uPAR) in NPC progression, which has not been investigated in NPC. We then observed that uPAR expression is increased in poorly differentiated, highly metastatic NPC cells compared with lowly metastatic cells or differentiated NPC cells. In vitro studies demonstrated that uPAR regulates NPC cell growth, colony formation, migration, and invasion and promotes the epithelial-mesenchymal transition (EMT). Additional tumor xenograft and spontaneous metastasis experiments revealed that uPAR promotes NPC cell growth and metastasis in vivo. The JAK-STAT pathway is involved in uPAR-regulated signaling in NPC cells as determined by immunoblotting. Moreover, uPAR-mediated growth and motility is partially abolished upon treatment with the Jak1/Jak2 inhibitor INCB018424. We suppressed uPA expression in uPAR-overexpressing NPC cells and found that uPAR-mediated cellular growth and motility is not exclusively dependent on uPA. In summary, uPAR is a significant regulator of NPC progression and could serve as a promising therapeutic target.
    Cell cycle (Georgetown, Tex.) 04/2014; 13(12). · 5.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Clear cell renal cell carcinoma (ccRCC) is a highly aggressive and common pathological subtype of renal cancer. This cancer is characterized by biallelic inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene, which leads to the accumulation of hypoxia-inducible factors (HIFs). Although therapies targeted at HIFs can significantly improve survival, nearly all patients with advanced ccRCC eventually succumb to the disease. Thus, additional oncogenic events are thought to be involved in the development of ccRCC tumors. In this study, we investigated the role of RASSF6 in ccRCC. Downregulation of RASSF6 was commonly observed in primary tumors relative to matched adjacent normal tissues. Moreover, functional studies established that ectopic re-expression of RASSF6 in ccRCC cells inhibited cell proliferation, clonogenicity, and tumor growth in mice, whereas silencing of RASSF6 dramatically enhanced cell proliferation in vitro and in vivo. Mechanistic investigation suggested that RASSF6 triggers p21(Cip1/Waf1) accumulation to induce G 1 cell cycle arrest and promote apoptosis upon exposure to pro-apoptotic agents, and both of these mechanisms appear to be mediated by activated JNK signaling. Together, these findings suggest that RASSF6 may play a tumor suppressor role in the progression of ccRCC.
    Cell cycle (Georgetown, Tex.) 03/2014; 13(9). · 5.24 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiation and cisplatin-based chemotherapy are major treatments for nasopharyngeal carcinoma (NPC). However, a major impediment for further improving the cure rate is the development of treatment resistance with an undetermined molecular mechanism in metastatic NPC cells. Our established, highly metastatic NPC cells have been reported to be more resistant to cisplatin chemotherapy. In the present study, we found that Ras association domain family member 6 (RASSF6) was downregulated in highly metastatic cells but upregulated in low metastatic cells in comparison to their parental cell line. Ectopic-expression of RASSF6 enhanced the sensitivity of highly metastatic NPC cells to cisplatin or radiation by enhancing apoptosis. RASSF6 depletion conversely reduced treatment sensitivity by decreasing the apoptosis rate. Over-expression of RASSF6 in highly metastatic NPC cells could enhance the phosphorylation of JNK when exposed to cisplatin or radiation treatment, while knocking down RASSF6 in low metastatic NPC cells could reduce the level of phospho-JNK when exposed to the same treatments. The activation of JNK signaling by RASSF6 and its subsequent sensitivity to apoptosis in NPC cells could be inhibited by applying the JNK inhibitor SP600125. In conclusion, the downregulation of RASSF6 in highly metastatic NPC cells contributed to their treatment resistance, and over-expression of RASSF6 conferred treatment sensitivity to highly metastatic NPC cells by activating JNK signaling. RASSF6 could be a valuable molecular marker for identifying sensitive metastatic NPC tumors during cisplatin treatment or radiotherapy.
    PLoS ONE 01/2014; 9(7):e100843. · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Global gene expression analysis was performed on pre-treatment biopsies from patients with squamous cell carcinoma of the head and neck (SCCHN) to discover biomarkers that can predict outcome of radiation based therapy. We initially evaluated RNA expression using cDNA microarray analysis of 38 patients that received radiotherapy (RT). The five strongest candidates (VEGF, BCL-2, CLAUDIN-4, YAP-1 and c-MET) were then analysed in pre-treatment biopsies in a second group of 86 patients who received radiation based treatment using immunohistochemical staining (IHC), prepared by tissue microarray. In the first population, 13 of 38 (34%) had no (NR) or partial response (PR) to RT. cDNA microarrays revealed 60 genes that were linked to response to therapy. In the second series, 12 of 86 patients (14%) experienced NR or PR to CRT. Cause specific survival (CSS) and recurrence free survival (RFS) at 2 years was 85% and 90% and at 3 years 81% and 84%, respectively. Biomarkers predictive for NR/PR were increased expression of vascular endothelial growth factor (VEGF) (p=0.02), Yes-associated protein (YAP-1) (p<0.01), CLAUDIN-4 (p<0.01), c-MET (p<0.01) and BCL-2 (p=0.02). Biomarkers predictive of poor RFS were YAP-1 (p=0.01) and BCL-2 (p<0.01). Biomarkers predictive of poor CSS were YAP-1 (p=0.04), VEGF (p=0.03) and CLAUDIN-4 (p=0.03). Furthermore, when YAP-1 and c-MET expression levels were combined the prediction of radio-resistance was increased. All five biomarkers were predictive of poor response to radiation based therapy. In particular, YAP-1 and c-MET have synergistic power and could be used to make treatment decisions.
    European journal of cancer (Oxford, England: 1990) 12/2013; · 4.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the prognostic role of major matrix metalloproteinase (MMP) gene polymorphisms in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated with chemoradiotherapy. Four hundred twenty-one consecutive NPC patients were prospectively recruited. Two hundred patients were randomly selected as the training cohort, and the remaining 221 patients were the validation cohort. Twelve polymorphisms in the MMP-1, 2, 3, 7, 8, and 9 genes were genotyped by ligase detection reaction-PCR. MMP-9 rs2250889 PR/RR (HR = 2.287, 95 % CI 1.400-3.735) and rs17576 RQ/QQ (HR = 2.347, 95 % CI 1.431-3.849) genotypes were significantly related with increased death risk in the training cohort. Analysis of the validation cohort confirmed these results (rs2250889: HR = 2.231, 95 % CI 1.281-3.886; rs17576: HR = 2.987, 95 % CI 1.674-5.330). Multivariate analysis showed that rs17576 (HR = 2.284, 95 % CI 1.123-4.643, P = 0.023) was still an independent prognostic factor. The MMP-9 rs17576 is a novel independent prognostic marker in patients with locoregionally advanced NPC treated with chemoradiotherapy.
    Medical Oncology 12/2013; 30(4):685. · 2.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Emerging evidence confirms that cancer stem cells (CSCs) are responsible for the chemoradioresistance of malignancies. EBV-encoded latent membrane protein 1 (LMP1) is associated with tumor relapse and poor prognosis of nasopharyngeal carcinoma (NPC). However, whether LMP1 induces the development of CSCs and the mechanism by which this rare cell subpopulation leads to radioresistance in NPC remain unclear. In the present study, LMP1-transformed NPC cells showed significant radioresistance compared to the empty vector control. We found that LMP1 up-regulated the expression of several stemness-related genes, increased the cell number of side population (SP) by flow cytometry analysis, enhanced the self-renewal properties of the cells in a spherical culture and enhanced the in vivo tumor initiation ability. We also found that LMP1 positively regulated the expression of the CSC marker CD44. The CD44(+/High) subpopulation of the LMP1-transformed NPC cells displayed more significant CSC characteristics than the CD44(-/Low) subpopulation of the LMP1-transfomed NPC cells; these characteristics included the upregulation of stemness-related genes, in vitro self-renewal and in vivo tumor initiation ability. Importantly, the CD44(+/High) subpopulation displayed more radioresistance than the CD44(-/Low) subpopulation. Our results also demonstrated that phosphorylation of the DNA damage response (DDR) proteins, ATM, Chk1, Chk2 and p53, was inactivated in the LMP1-induced CD44(+/High) cells in response to DNA damage, and this was accompanied by a downregulation of the p53-targeted proapoptotic genes, which suggested that the inactivation of the p53-mediated apoptosis pathway was responsible for the radioresistance in the CD44(+/High) cells. Taken together, we found that LMP1 induced an increase in CSC-like CD44(+/High) cells, and we determined the molecular mechanism underlying the radioresistance of the LMP1-activated CSCs, highlighting the need of CSC-targeted radiotherapy in EBV-positive NPC.
    Cancer letters 11/2013; · 4.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Systemic chemotherapy is the basic palliative treatment for metastatic nasopharyngeal carcinoma (NPC); however, it is not known whether locoregional radiotherapy targeting the primary tumor and regional lymph nodes affects the survival of patients with metastatic NPC. Therefore, we aimed to retrospectively evaluate the benefits of locoregional radiotherapy. A total of 408 patients with metastatic NPC were included in this study. The mortality risks of the patients undergoing supportive treatment and those undergoing chemotherapy were compared with that of patients undergoing locoregional radiotherapy delivered alone or in combination with chemotherapy. Univariate and multivariate analyses were conducted. The contributions of independent factors were assessed after adjustment for covariates with significant prognostic associations (P < 0.05). Both locoregional radiotherapy and systemic chemotherapy were identified as significant independent prognostic factors of overall survival (OS). The mortality risk was similar in the group undergoing locoregional radiotherapy alone and the group undergoing systemic chemotherapy alone [multi-adjusted hazard ratio (HR) = 0.9, P = 0.529]; this risk was 60% lower than that of the group undergoing supportive treatment (HR = 0.4, P = 0.004) and 130% higher than that of the group undergoing both systemic chemotherapy and locoregional radiotherapy (HR = 2.3, P < 0.001). In conclusion, locoregional radiotherapy, particularly when combined with systemic chemotherapy, is associated with improved survival of patients with metastatic NPC.
    Ai zheng = Aizheng = Chinese journal of cancer 11/2013; 32(11):604-613.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Epstein-Barr virus (EBV) is an etiological cause of many human lymphocytic and epithelial malignancies. EBV expresses different genes that are associated with three latency types. To date, as many as 44 EBV-encoded miRNA species have been found, but their comprehensive profiles in the three types of latent infection that are associated with various types of tumors are not well documented. In the present study, we utilized poly (A)-tailed quantitative real-time RT-PCR in combination with microarray analysis to measure the relative abundances of viral miRNA species in a subset of representative lymphoid and epithelial tumor cells with various EBV latency types. Our findings showed that the miR-BHRF1 and miR-BART families were expressed differentially in a tissue- and latency type-dependent manner. Specifically, in nasopharyngeal carcinoma (NPC) tissues and the EBV-positive cell line C666-1, the miR-BART family accounted for more than 10% of all detected miRNAs, suggesting that these miRNAs have important roles in maintaining latent EBV infections and in driving NPC tumorigenesis. In addition, EBV miRNA-based clustering analysis clearly distinguished between the three distinct EBV latency types, and our results suggested that a switch from type I to type III latency might occur in the Daudi BL cell line. Our data provide a comprehensive profiling of the EBV miRNA transcriptome that is associated with specific tumor cells in the three types of latent EBV infection states. EBV miRNA species represent a cluster of non-encoding latency biomarkers that are differentially expressed in tumor cells and may help to distinguish between the different latency types.
    Virology Journal 10/2013; 10(1):314. · 2.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Platinum-based concurrent chemo-radiotherapy is considered a standard treatment approach for locoregionally advanced nasopharyngeal carcinoma (NPC). However, only a minority of patients benefit from this treatment regimen compared to radiotherapy alone. Identification of a set of molecular markers predicting sensitivity of platinum-based chemotherapy may contribute to personalized treatment of NPC patients for better clinical outcome with less toxicity. Previously, we generated a cisplain sensitive NPC cell line, S16, by clonal selection from CNE-2 cells and found that eIF3a is up-regulated and contributes to cisplatin sensitivity by down-regulating the synthesis of NER proteins. In this study, we conducted a gene expression profiling analysis and found three other genes, asparagine synthetase (ASNS), choriogonadotropin α subunit (CGA), and matrix metalloproteinase 19 (MMP19), that are up-regulated in the cisplatin-sensitive S16 cells compared with the CNE-2 cells. However, only ASNS and MMP19, but not CGA, contributes to cisplatin sensitivity by potentiating cisplatin-induced DNA damage and apoptosis. Thus, ASNS and MMP19, along with eIF3a, are sensitivity factors for cisplatin treatment and may serve as potential candidate molecular markers for predicting cisplatin sensitivity of advanced nasopharyngeal carcinoma.
    Molecular Cancer Therapeutics 08/2013; · 5.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aristolochic acid (AA), a natural product of Aristolochia plants found in herbal remedies and health supplements, is a group 1 carcinogen that can cause nephrotoxicity and upper urinary tract urothelial cell carcinoma (UTUC). Whole-genome and exome analysis of nine AA-associated UTUCs revealed a strikingly high somatic mutation rate (150 mutations/Mb), exceeding smoking-associated lung cancer (8 mutations/Mb) and ultraviolet radiation-associated melanoma (111 mutations/Mb). The AA-UTUC mutational signature was characterized by A:T to T:A transversions at the sequence motif A[C|T]AGG, located primarily on nontranscribed strands. AA-induced mutations were also significantly enriched at splice sites, suggesting a role for splice-site mutations in UTUC pathogenesis. RNA sequencing of AA-UTUC confirmed a general up-regulation of nonsense-mediated decay machinery components and aberrant splicing events associated with splice-site mutations. We observed a high frequency of somatic mutations in chromatin modifiers, particularly KDM6A, in AA-UTUC, demonstrated the sufficiency of AA to induce renal dysplasia in mice, and reproduced the AA mutational signature in experimentally treated human renal tubular cells. Finally, exploring other malignancies that were not known to be associated with AA, we screened 93 hepatocellular carcinoma genomes/exomes and identified AA-like mutational signatures in 11. Our study highlights an unusual genome-wide AA mutational signature and the potential use of mutation signatures as "molecular fingerprints" for interrogating high-throughput cancer genome data to infer previous carcinogen exposures.
    Science translational medicine 08/2013; 5(197):197ra101. · 10.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSETo evaluate which patients with nasopharyngeal carcinoma (NPC) obtained the greatest benefits from the detection of distant metastasis with [(18)F]fluorodeoxyglucose positron emission tomography and computed tomography (PET/CT) combined with plasma Epstein-Barr virus (EBV) DNA levels. PATIENTS AND METHODS Consecutive patients with NPC were prospectively enrolled. PET/CT, conventional work-up (CWU), and quantification of plasma EBV DNA were performed before treatment. The accuracy of these strategies for distant metastases was assessed. The costs of the diagnostic strategies were compared.ResultsEighty-six (14.8%) of the 583 eligible patients were found to have distant metastases; 71 patients (82.6%) by PET/CT and 31 patients (36.0%) by CWU. In the multivariable analysis, advanced N stage (odds ratio, 2.689; 95% CI, 1.894 to 3.818) and pretreatment EBV DNA level (odds ratio, 3.344; 95% CI, 1.825 to 6.126) were significant risk factors for distant metastases. PET/CT was not superior to CWU for detecting distant metastases in very low-risk patients (N0-1 with EBV DNA < 4,000 copies/mL; P = .062), but was superior for the low-risk patients (N0-1 with EBV DNA ≥ 4,000 copies/mL and N2-3 with EBV DNA < 4,000 copies/mL; P = .039) and intermediate-risk patients (N2-3 disease with EBV DNA ≥ 4,000 copies/mL; P < .001). The corresponding patient management changes based on PET/CT were 2.9%, 6.3%, and 16.5%, respectively. The costs per true-positive case detected by PET/CT among these groups were ¥324,138 (≈$47,458), ¥96,907 (≈$14,188), and ¥34,182 (≈$5,005), respectively. CONCLUSIONPET/CT detects more distant metastases than conventional staging in patients with NPC. The largest benefit in terms of cost and patient management was observed in the subgroup with N2-3 disease and EBV DNA ≥ 4,000 copies/mL.
    Journal of Clinical Oncology 07/2013; · 18.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: Chronic inflammation plays an important role in nasopharyngeal carcinoma (NPC) development and progression. Aim of this study is to determine whether inflammation-related parameters predict distant metastasis in NPC patients. MATERIALS AND METHODS: 335 newly diagnosed non-metastatic NPC patients were recruited. The values of the C-reactive protein (CRP), lactate dehydrogenase, albumin, globulin, white blood cell and neutrophil at baseline were measured. RESULTS: Among the above six parameters, only CRP was independently associated with distant metastasis-free survival (DMFS). CRP concentration of advanced T-/TNM-classification patients was higher than those with early classification (P=0.001). Higher-CRP (CRP⩾2.46mg/L) predicted shorter overall survival, disease-free survival and DMFS than lower-CRP (CRP<2.46mg/L). In a multivariable model, higher-CRP and advanced N-classification were independent predictors of distant metastasis. On the basis of these two parameters, a prognostic NC-model was developed as following: (1) low-risk (early N-classification and lower-CRP); (2) intermediate-risk (advanced N-classification or higher-CRP) and (3) the high-risk distant metastasis (advanced N-classification and higher-CRP). When compared with the low-risk group, the hazard ratios (HRs) for distant metastasis and death for the intermediate-/high-risk patients were 3.6/16.1 and 2.26/7.61, respectively (both P<0.001). CONCLUSION: We developed a new prognostic model based on CRP and N-classification for predicting distant metastasis and death of NPC patients, which may facilitate patient counselling and individualised treatment.
    European journal of cancer (Oxford, England: 1990) 04/2013; · 4.12 Impact Factor
  • Chao-Nan Qian
    [Show abstract] [Hide abstract]
    ABSTRACT: The most common type of malignancy in the adult kidney is clear cell renal cell carcinoma (ccRCC), for which antiangiogenic therapy with surgery is currently the standard treatment. Although overall survival of patients with metastatic ccRCC has been substantially extended by antiangiogenic therapy with agents such as sorafenib and sunitinib, patients almost certainly go on to develop resistance, or present at the time of treatment with primary resistance. This eventuality implies that our knowledge of the processes involved in tumour angiogenesis in ccRCC is superficial. Increasing evidence has shown that a solid tumour can, during invasion and expansion, 'hijack' pre-existing blood vessels and integrate them into the tumour vasculature. This approach to expanding the tumour vasculature is referred to as vessel co-option. In this Perspectives article, I argue that vessel co-option likely occurs in ccRCC, along with the complementary processes of vessel remodelling and extratumoural angiogenesis. Exploring the underlying molecular mechanisms of these complicated vasculature developments in ccRCC might provide new opportunities to enhance the efficacy of antiangiogenic therapy.
    Nature Reviews Urology 03/2013; · 4.79 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Approximately 30% of patients with Epstein-Barr virus (EBV)-positive advanced nasopharyngeal carcinoma (NPC) display chemoresistance to cisplatin-based regimens, but the underlying mechanisms are unclear. The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1), a functional homologue of the tumor necrosis factor receptor family, contributes substantially to the oncogenic potential of EBV through the activation of multiple signaling pathways, and it is closely associated with a poorer prognosis for NPC. Recent studies show that EBV infection can induce the expression of many cellular miRNAs, including microRNA-21, a biomarker for chemoresistance. However, neither a link between LMP1 expression and miR-21 upregulation nor their cross talk in affecting chemoresistance to cisplatin have been reported. Here, we observed that stable LMP1-transformed NPC cells were less sensitive to cisplatin treatment based on their proliferation, colony formation, the IC50 value of cisplatin and the apoptosis index. Higher levels of miR-21 were found in EBV-carrying and LMP1-positive cell lines, suggesting that LMP1 may be linked to miR-21 upregulation. These data were confirmed by our results that exogenous LMP1 increased miR-21 in both transiently and stably LMP1-transfected cells, and the knock down of miR-21 substantially reversed the resistance of the NPC cells to cisplatin treatment. Moreover, the proapoptotic factors programmed cell death 4 (PDCD4) and Fas ligand (Fas-L), which were negatively regulated by miR-21, were found to play an important role in the program of LMP1-dependent cisplatin resistance. Finally, we demonstrated that LMP1 induced miR-21 expression primarily by modulating the PI3K/AKT/FOXO3a signaling pathway. Taken together, we revealed for the first time that viral LMP1 triggers the PI3K/Akt/FOXO3a pathway to induce human miR-21 expression, which subsequently decreases the expression of PDCD4 and Fas-L, and results in chemoresistance in NPC cells.
    PLoS ONE 01/2013; 8(10):e78355. · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Treatment outcomes vary greatly in patients with nasopharyngeal carcinoma (NPC). The purpose of this study is to evaluate the influence of radiation and chemotherapy drug action pathway gene polymorphisms on the survival of patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy. Four hundred twenty-one consecutive patients with locoregionally advanced NPC were prospectively recruited. We utilized a pathway approach and examined 18 polymorphisms in 13 major genes. Polymorphisms were detected using the LDR-PCR technique. Multifactor dimensionality reduction (MDR) analysis was performed to detect potential gene-gene interaction. After adjustment for clinicopathological characteristics, overall survival was significantly decreased in patients with the MPO rs2243828 CT/CC genotype (HR=2.453, 95% CI, 1.687-3.566, P<0.001). The ERCC1 rs3212986 CC (HR=1.711, 95% CI, 1.135-2.579, P=0.010), MDM2 rs2279744 GT/GG (HR=1.743, 95% CI, 1.086-2.798, P=0.021), MPO rs2243828 CT/CC (HR=3.184, 95% CI, 2.261-4.483, P<0.001) and ABCB1 rs2032582 AT/AA (HR=1.997, 95% CI, 1.086-3.670, P=0.026) genotypes were associated with poor progression-free survival. Prognostic score models based on independent prognostic factors successfully classified patients into low-, intermediate-, and high-risk groups. Furthermore, MDR analysis showed no significant interaction between polymorphisms. Four single nucleotide polymorphisms were associated with survival in patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy. Combining clinical prognostic factors with genetic information was valuable in identifying patients with different risk.
    PLoS ONE 01/2013; 8(12):e82750. · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Dovitinib is a receptor tyrosine kinase (RTK) inhibitor targeting vascular endothelial growth factor receptors, fibroblast growth factor receptors and platelet-derived growth factor receptor beta. Dovitinib is currently in clinical trials for the treatment of hepatocellular carcinoma (HCC). METHOD: In this study, we used five HCC cell lines and five endothelial cell lines to validate molecular and cellular targets of dovitinib. RESULTS: Tumor growth and pulmonary metastasis were significantly suppressed in an orthotopic HCC model. Immunoblotting revealed that among known dovitinib targets, only PDGFR-beta was expressed in two HCC cell lines, while four of five endothelial lines expressed PDGFR-beta, FGFR-1, and VEGFR-2. Dovitinib inhibited endothelial cell proliferation and motility at 0.04 mumol/L, a pharmacologically relevant concentration; it was unable to inhibit the proliferation or motility of HCC cells at the same concentration. Immunohistochemical analyses showed that dovitinib significantly decreased the microvessel density of xenograft tumors, inhibiting proliferation and inducing apoptosis in HCC cells. CONCLUSION: Our findings indicate that dovitinib inhibits HCC growth and metastasis preferentially through an antiangiogenic mechanism, not through direct targeting of HCC cells.
    Journal of Translational Medicine 12/2012; 10(1):245. · 3.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A large amount of nicotinamide adenine dinucleotide phosphate (NADPH) is required for fatty acid synthesis and maintenance of the redox state in cancer cells. Malic enzyme 1 (ME1)-dependent NADPH production is one of the three pathways that contribute to the formation of the cytosolic NADPH pool. ME1 is generally considered to be overexpressed in cancer cells to meet the high demand for increased de novo fatty acid synthesis. In the present study, we found that glucose induced higher ME1 activity and that repressing ME1 had a profound impact on glucose metabolism of nasopharyngeal carcinoma cells. High incorporation of glucose and an enhancement of the pentose phosphate pathway were observed in ME1-repressed cells. However, there were no obvious changes in the other two pathways for glucose metabolism: glycolysis and oxidative phosphorylation. Interestingly, NADPH was decreased under low-glucose conditions in ME1-repressed cells relative to wild-type cells, whereas there was no significant difference under high-glucose conditions. ME1-repressed cells had significantly decreased tolerance to low glucose conditions. Moreover, NADPH produced by ME1 was not only important for fatty acid synthesis but also essential for maintenance of the intracellular redox state and the protection of cells from oxidative stress. Furthermore, diminished migration and invasion were observed in ME1-repressed cells due to a reduced level of Snail protein. Collectively, these results suggest an essential role for ME1 in the production of cytosolic NADPH and maintenance of cellular migratory and invasive abilities in nasopharyngeal carcinoma cells.
    Chinese journal of cancer 11/2012;

Publication Stats

1k Citations
441.97 Total Impact Points

Institutions

  • 2008–2014
    • Sun Yat-Sen University Cancer Center
      • Department of Radiation Oncology
      Shengcheng, Guangdong, China
  • 2013
    • National Cancer Centre Singapore
      • Department of Medical Sciences
      Singapore
  • 2004–2013
    • Sun Yat-Sen University
      • State Key Laboratory of Oncology
      Shengcheng, Guangdong, China
  • 2002–2013
    • Van Andel Research Institute
      Grand Rapids, Michigan, United States
  • 2009
    • Singapore General Hospital
      • Department of General Surgery
      Tumasik, Singapore
  • 1998
    • Sun Yat-Sen University of Medical Sciences
      • Cancer Center
      Guangzhou, Guangdong Sheng, China