[Show abstract][Hide abstract] ABSTRACT: Tumor growth and metastasis depend on the establishment of tumor vasculature to provide oxygen, nutrients, and other essential factors. The well-known vascular endothelial growth factor (VEGF) signaling is crucial for sprouting angiogenesis as well as recruitment of circulating progenitor endothelial cells to tumor vasculature, which has become therapeutic targets in clinical practice. However, the survival benefits gained from targeting VEGF signaling have been very limited, with the inevitable development of treatment resistance. In this article, we discuss the most recent findings and understanding on how solid tumors evade VEGF-targeted therapy, with a special focus on vessel co-option, vessel remodeling, and tumor cell-derived vasculature establishment. Vessel co-option may occur in tumors independently of sprouting angiogenesis, and sprouting angiogenesis is not always required for tumor growth. The differences between vessel-like structure and tubule-like structure formed by tumor cells are also introduced. The exploration of the underlying mechanisms of these alternative angiogenic approaches would not only widen our knowledge of tumor angiogenesis but also provide novel therapeutic targets for better controlling cancer growth and metastasis.
Preview · Article · Dec 2016 · Chinese journal of cancer
[Show abstract][Hide abstract] ABSTRACT: This study aimed to evaluate the prognostic value of plasma Epstein-Barr Virus DNA (EBV DNA) for local and regionally advanced nasopharyngeal carcinoma (NPC) patients treated with concurrent chemoradiotherapy in intensity-modulated radiotherapy (IMRT) era.In this observational study, 404 nonmetastatic local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy were recruited. Blood samples were collected before treatment for examination of plasma EBV DNA levels. We evaluated the association of pretreatment plasma EBV DNA levels with progression-free survival rate (PFS), distant metastasis-free survival rate (DMFS), and overall survival rate (OS).Compared to patients with an EBV DNA level <4000 copies/mL, patients with an EBV DNA ≥4000 copies/mL had a lower rate of 3-year PFS (76%, 95% CI [68-84]) versus (93%, 95% CI [90-96], P < 0.001), DMFS (83%, 95% CI [76-89]) versus (97%, 95% CI [94-99], P < 0.001), and OS (85%, 95% CI [78-92]) versus (98%, 95% CI [95-100], P < 0.001). Multivariate analysis showed that pretreatment EBV DNA levels (HR = 3.324, 95% CI, 1.80-6.138, P < 0.001) and clinical stage (HR = 1.878, 95% CI, 1.036-3.404, P = 0.038) were the only independent factor associated with PFS, pretreatment EBV DNA level was the only significant factor to predict DMFS (HR = 6.292, 95% CI, 2.647-14.956, P < 0.001), and pretreatment EBV DNA levels (HR = 3.753, 95% CI, 1.701-8.284, P < 0.001) and clinical stage (HR = 2.577, 95% CI, 1.252-5.050, P = 0.010) were significantly associated with OS. In subgroup analysis, higher plasma EBV DNA levels still predicted a worse PFS, DMFS, and OS for the patients stage III or stage IVa-b, compared with those with low EBV DNA levels.Elevated plasma EBV DNA was still effective prognostic biomarker for local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy. Future ramdomized clinical trials are needed to further evaluate whether plasma EBV DNA levels could be applied to guide concurrent chemotherapy regimen for local and regionally advanced NPC patients.
[Show abstract][Hide abstract] ABSTRACT: There is very little published information regarding the prognostic value of hemoglobin (Hb) levels combined with smoking on the survival of patients with nasopharyngeal carcinoma (NPC), and the interactions between them remain unclear. A total of 2440 NPC patients were confirmed, and multivariate analysis was performed to identify valuable prognostic Hb levels in the entire population and in the cohort of smokers. The survival differences were compared using log-rank tests. The multiplicative and additive interactions were assessed using Cox regression and a Microsoft Word Excel spreadsheet. Postradiotherapy (RT) Hb was an independent prognostic factor for overall survival (OS) (HR = 0.797; P = 0.006), failure-free survival (FFS) (HR=0.811; P = 0.010), and loco-regional failure-free survival (LR-FFS) (HR = 0.725; P = 0.000). In the cohort of smokers, pack-years was also an independent predictor of OS (HR = 0.673; P < 0.001) and FFS (HR = 0.681; P < 0.001), LR-FFS (HR = 0.663; P = 0.001). A significant positive additive effect was found for the interaction between low post-RT Hb and high SI on OS, with RERI = 5.616, AP = 0.665, and S = 4.078. Stratified analyses demonstrated that heavy smokers with low post-RT Hb had HRs of 2.295 (P < 0.001) for death, 2.222 (P < 0.001) for disease failure, and 2.267 (P < 0.001) loco-regional recurrence compared with light smokers with high post-RT Hb levels, and post-RT Hb level is an important predictor of survival in patients with NPC. The positive interaction between post-RT Hb level and pack-years contributes to the elevated risk of poor survival. Oncologists should devote particular attention to heavy smokers with low post-RT Hb levels in the future.
[Show abstract][Hide abstract] ABSTRACT: Background:
Upper urinary tract urothelial carcinoma (UUTUC) is one of the uncommon malignancies lacking of prognostic indicators. Lactate dehydrogenase (LDH) has been demonstrated to correlate with clinical outcomes in human cancers. In this study, we aimed to evaluate the prognostic implication of the preoperative LDH in UUTUC.
Patients and methods:
A cohort of 100 UUTUC samples along with the preoperative LDH value was recruited from January 1990 to June 2011. The cutoff value was set at 245 u/L for the upper value of normal limitation. Univariate and multivariate analyses were conducted to determine the association of LDH with overall survival (OS) and disease-free survival (DFS).
Kaplan-Meier analysis revealed that high level of LDH (> 245 u/L) was significantly associated with poor OS (P < .001) and DFS (P = .002). Multivariate Cox proportional analysis indicated LDH, controlled by vascular invasion, pathological stage, lymph node status, subsequent bladder tumor, tumor grade, tumor necrosis, architecture, and multifocality, was as an independent predictor of OS (hazard ratio, 3.181; 95% confidence interval, 1.223-8.276; P = .018) and DFS (hazard ratio, 3.041; 95% confidence interval, 1.247-7.417; P = .015). Stratified showed that elevated serum LDH was correlated with the worse OS in patients without lymph node metastasis (P = .002) and those at advanced pathological stage (P < .001).
The preoperative LDH was an independent prognostic factor for patients with UUTUC and could be used as a risk factor to predict the tumor aggressiveness.
No preview · Article · Jan 2016 · Clinical Genitourinary Cancer
[Show abstract][Hide abstract] ABSTRACT: Background:
This study aimed to establish an effective prognostic nomogram with or without plasma Epstein-Barr virus DNA (EBV DNA) for nondisseminated nasopharyngeal carcinoma (NPC).
The nomogram was based on a retrospective study of 4630 patients who underwent radiotherapy with or without chemotherapy at Sun Yat-sen University Cancer Center from 2007 to 2009. The predictive accuracy and discriminative ability of the nomogram were determined by a concordance index (C-index) and calibration curve and were compared with EBV DNA and the current staging system. The results were validated using bootstrap resampling and a prospective cohort study on 1819 patients consecutively enrolled from 2011 to 2012 at the same institution. All statistical tests were two-sided.
Independent factors derived from multivariable analysis of the primary cohort to predict recurrence were age, sex, body mass index (BMI), T stage, N stage, plasma EBV DNA, pretreatment high sensitivity C-reactive protein (hs-CRP), lactate dehydrogenase (LDH), and hemoglobin level (HGB), which were all assembled into the nomogram with (nomogram B) or without EBV DNA (nomogram A). The calibration curve for the probability of recurrence showed that the nomogram-based predictions were in good agreement with actual observations. The C-index of nomogram B for predicting recurrence was 0.728 (P < .001), which was statistically higher than the C-index values for nomogram A (0.690), EBV DNA (0.680), and the current staging system (0.609). The C-index of nomogram B (0.730) and nomogram A (0.681) remained higher for predicting recurrence among patients treated with intensity-modulated radiotherapy (P < .001). The results were confirmed in the validation cohort.
The proposed nomogram with or without plasma EBV DNA resulted in more accurate prognostic prediction for NPC patients.
No preview · Article · Jan 2016 · JNCI Journal of the National Cancer Institute
[Show abstract][Hide abstract] ABSTRACT: Background:
The objective of this study is to verify the prognostic value of pretreatment plasma Epstein-Barr viral deoxyribonucleic acid (pEBV DNA) levels in nasopharyngeal carcinoma (NPC) patients to complement TNM classification based on the application of the intensity-modulated radiotherapy (IMRT) technique.
In total, 1467 patients staged at I-IVa-b (M0) and treated with IMRT were retrospectively analyzed at our cancer center from January 2007 to December 2010. Patient survival among different stages and EBV DNA levels were compared.
Outcome analyses of different stages and EBV DNA levels revealed that patients in stages II-III with low EBV DNA levels had similar survival as that of patients in stages IVa-b with low EBV DNA (5-yr overall survival (OS), 94.7% vs. 92.9% (P = 0.141), progression failure-free survival (PFS), 87.2% vs. 89.0% (P = 0.685), distant metastasis failure-free survival (DMFS), 93.5% vs. 92.4% (P = 0.394) and locoregional failure-free survival (LRFS), 93.8% vs. 96.3% (P = 0.523)). Conversely, patients in stages II-III with high EBV DNA had better survival than patients in stages IVa-b with high EBV DNA (5-yr OS, 82.7% vs. 71.7% (P = 0.001), PFS, 70.7% vs. 66.2% (P = 0.047), DMFS, 79.6% vs. 74.8% (P = 0.066) and LRFS, 89.3% vs. 87.6% (P = 0.425)) but poorer survival than patients in stages IVa-b with low EBV DNA (5-yr OS, 82.7% vs. 92.9% (P = 0.025), PFS, 70.7% vs. 89.0, (P < 0.001), DMFS, 79.6% vs. 92.4%, (P = 0.001), LRFS, 89.3% vs. 96.3%, (P = 0.022)).
pEBV DNA is a strong prognostic factor for patients with NPC when complemented with TNM staging in the era of IMRT application.
[Show abstract][Hide abstract] ABSTRACT: Background:
The impact of cumulative dose of cisplatin on clinical outcomes of nasopharyngeal carcinoma (NPC) patients who received intensity-modulated radiotherapy (IMRT) was evaluated.
This study included 491 consecutive patients with histologically confirmed NPC who were treated with concurrent chemoradiotherapy with IMRT. The patients were divided into three groups: low- (cumulative dose ≤100 mg/m(2)), medium- (cumulative dose >100 mg/m(2) and ≤200 mg/m(2)), and high- (cumulative dose >200 mg/m(2)) dose groups. Subgroups of patients included pre-treatment levels of Epstein-Barr Virus DNA (EBV DNA) <4000 copies/ml and pre-treatment EBV DNA ≥4000 copies/ml. To test for independent significance, the Kaplan-Meier with the log-rank test and the Cox proportional hazards model were used.
The 5-year overall survival (OS) rates of the low-, medium-, and high-dose groups were 64.1 %, 91.1 %, and 89.4 %, respectively (P = 0.002). Based on multivariate analysis, patients who were in the medium- and high-dose groups had compared with the low-dose group, with an odds ratio of 0.135 (95 % CI 0.045-0.405, P < 0.001) and 0.225 (95 % CI 0.069-0.734, P = 0.013), respectively. For the low-risk patients, the cumulative dose of cisplatin significantly associated with a lower OS (P < 0.001). The medium-dose group had reduced odds of death compared with the low-dose group, with an odds ratio of 0.062 (95 % CI 0.001-0.347, P = 0.002), according to multivariate analysis.
The cumulative dose of cisplatin is associated with OS and distant metastasis-free survival (DMFS) among NPC patients who received IMRT.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to develop a prognostic classifier and subdivided the M1 stage for nasopharyngeal carcinoma patients with synchronous metastases (mNPC). A retrospective cohort of 347 mNPC patients was recruited between January 2000 and December 2010. Thirty hematological markers and 11 clinical characteristics were collected, and the association of these factors with overall survival (OS) was evaluated. Advanced machine learning schemes of a support vector machine (SVM) were used to select a subset of highly informative factors and to construct a prognostic model (mNPC-SVM). The mNPC-SVM classifier identified ten informative variables, including three clinical indexes and seven hematological markers. The median survival time for low-risk patients (M1a) as identified by the mNPC-SVM classifier was 38.0 months, and survival time was dramatically reduced to 13.8 months for high-risk patients (M1b) (P < 0.001). Multivariate adjustment using prognostic factors revealed that the mNPC-SVM classifier remained a powerful predictor of OS (M1a vs. M1b, hazard ratio, 3.45; 95% CI, 2.59 to 4.60, P < 0.001). Moreover, combination treatment of systemic chemotherapy and loco-regional radiotherapy was associated with significantly better survival outcomes than chemotherapy alone (the 5-year OS, 47.0% vs. 10.0%, P < 0.001) in the M1a subgroup but not in the M1b subgroup (12.0% vs. 3.0%, P = 0.101). These findings were validated by a separate cohort. In conclusion, the newly developed mNPC-SVM classifier led to more precise risk definitions that offer a promising subdivision of the M1 stage and individualized selection for future therapeutic regimens in mNPC patients.
[Show abstract][Hide abstract] ABSTRACT: Nasopharyngeal carcinoma (NPC) has the highest metastasis potential among head and neck cancers. Distant metastasis is the major cause of treatment failure. Recent studies from our laboratory have revealed that IL-8 promotes NPC metastasis via activation of AKT signaling and induction of epithelial-mesenchymal transition (EMT) in the cells. In the present study, we found that IL-8 treatment for NPC cells resulted in an accumulation of DNMT1 protein through activating AKT1 pathway and consequent DNMT1 protein stabilization. Then DNMT1 suppressed E-cadherin expression by increasing the methylation of its promoter region. LY-294002 blocked IL-8-induced p-AKT1 activation resulting in reduction of DNMT1 and increase of E-cadherin expression, whereas forced demethylation using 5-aza-2'-deoxycytidine restored E-cadherin expression. In conclusion, our study, for the first time, shows that the IL-8/AKT1 signaling pathway stabilizes DNMT1 protein, consequently enhancing hypermethylation of E-cadherin promoter regions and downregulating E-cadherin protein level in NPC cells. Upon blockage of the IL-8/AKT pathway and inhibition of DNMT1, E-cadherin expression can be reversed. These data suggest that targeting the IL-8/AKT1 signaling pathway and DNMT1 may provide a potential therapeutic approach for blocking NPC metastasis.
No preview · Article · Nov 2015 · International Journal of Oncology
[Show abstract][Hide abstract] ABSTRACT: Background:
This study aimed to evaluate the value of combining the nodal maximal standard uptake values (SUVmax) of 18 F-fluoro-2-deoxy-D-glucose positron emission tomography with Epstein-Barr virus DNA(EBV DNA) levels to predict distant metastasis for nasopharyngeal carcinoma (NPC) patients Patients and Methods: Eight hundred seventy-four patients with stage III-IVa-b NPC were evaluated for the effects of combining SUVmax and EBV DNA levels on distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS).
The optimal cutoff value was 6,220 copies/mL for EBV DNA and 7.5 for SUVmax-N. Patients with lower EBV DNA levels or SUVmax-N had a significantly better 3-year DMFS, DFS, and OS. Patients were divided into four groups based on EBV DNA and SUVmax-N, as follows: low EBV DNA and low SUVmax-N (LL), low EBV DNA and high SUVmax-N (LH), high EBV DNA and low SUVmax-N (HL), and high EBV DNA and high SUVmax-N (HH). There were significant differences between the four mentioned groups in 3-year DMFS: 95.7%, 92.2%, 92.3%, and 80.1%, respectively (Ptrend < 0.001). When looking at the disease stage, the 3-year DMFS in group LL, LH, HL, HH were 94.2%, 92.9%, 95.0%, and 81.1%, respectively, in stage III patients (Ptrend < 0.001) and 92.7%, 87.2%, 86.3%, and 77.0% in stage IVa-b patients (Ptrend = 0.026).
Pretreatment EBV DNA and SUVmax of neck lymph nodes were independent prognostic factors for distant metastasis in NPC patients. Combining EBV DNA and SUVmax-N led to an improved risk stratification for distant metastasis in advanced-stage disease.
[Show abstract][Hide abstract] ABSTRACT: Wnt3a, one of Wnt family members, plays key roles in regulating pleiotropic cellular functions, including self-renewal, proliferation, differentiation, and motility. Accumulating evidence has suggested that Wnt3a promotes or suppresses tumor progression via the canonical Wnt signaling pathway depending on cancer type. In addition, the roles of Wnt3a signaling can be inhibited by multiple proteins or chemicals. Herein, we summarize the latest findings on Wnt3a as an important therapeutic target in cancer.
Full-text · Article · Sep 2015 · Ai zheng = Aizheng = Chinese journal of cancer
[Show abstract][Hide abstract] ABSTRACT: Objective:
Tumor necrosis has been indicated as a factor for the poor clinical outcome in human cancers. We aim to disclose the association between tumor necrosis and overall survival and recurrence-free survival in node-negative upper urinary tract urothelial carcinoma patients treated with radical nephroureterectomy.
A retrospective cohort of 100 patients with upper urinary tract urothelial carcinoma from January 1990 to June 2011 was enrolled in this study. Univariate analysis with Log-rank test and multivariate analysis with Cox proportional hazards regression models were conducted to determine the correlations of tumor necrosis with overall survival and recurrence-free survival.
Tumor necrosis was presented in 48 patients with upper urinary tract urothelial carcinoma and was significantly associated with the advanced pathological stage (P < 0.001), high tumor grade (P < 0.001), subsequent bladder tumor (P = 0.018), vascular invasion (P < 0.001) and lymph node metastasis (P = 0.026). Multivariate analysis revealed tumor necrosis as an independent unfavorable predictor of overall survival in node-negative upper urinary tract urothelial carcinoma patients by multivariate analysis (hazard ratio = 9.23, 95% confidence interval = 1.05-80.89, P = 0.045).
Tumor necrosis was an independent factor of adverse clinical outcomes in node-negative upper urinary tract urothelial carcinoma patients who received radical nephroureterectomy. Evaluation of tumor necrosis might be of clinical significance to determine whether patients with node-negative upper urinary tract urothelial carcinoma should be given further therapy after radical nephroureterectomy.
No preview · Article · Sep 2015 · Japanese Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Our aim was to evaluate the correlation between tumor vasculature detected by pre-surgical contrast-enhanced ultrasonography and the post-surgical prognosis of patients with hepatocellular carcinoma. One hundred ninety-five patients with hepatocellular carcinoma who had undergone curative resection and pre-operative contrast-enhanced ultrasonography were enrolled. Intra-tumoral microvessels were evaluated by immunohistochemical staining for anti-CD31 and anti-CD34. On the basis of the immunohistochemical staining and morphology patterns, tumors were divided into capillary-like and sinusoid-like microvessel subtypes. The rise time of tumors was shorter in the capillary-like microvessel subtype than in the sinusoid-like microvasculature subtype (p = 0.026). Intra-tumor microvascular density (p < 0.001, hazard ratio = 0.137) and rise time (p = 0.006, hazard ratio = 2.475) were independent factors corresponding to different microvasculature types. Microvascular density, vascular invasion and wash-in perfusion index were determined to be independent factors in recurrence-free survival and overall survival. In conclusion, contrast-enhanced ultrasonography may serve as a means of non-invasive assessment of tumor angiogenesis and may be associated with the survival of patients with hepatocellular carcinoma after resection.
No preview · Article · Aug 2015 · Ultrasound in medicine & biology
[Show abstract][Hide abstract] ABSTRACT: Background:
Hemoglobin (Hb) levels are regarded as an important determinant of outcome in a number of cancers treated with radiotherapy. However, for patients treated with intensity modulated radiotherapy (IMRT), information regarding the prognostic value of hemoglobin level is scarce.
Patients and methods:
A total of 650 patients with nasopharyngeal carcinoma (NPC), enrolled between May, 2005, and November, 2012, were included in this study. The prognostic significance of hemoglobin level (anemia or no-anemia) at three different time points was investigated, including before treatment, during treatment and at the last week of treatment. Univariate and multivariate analyses were conducted using the log-rank test and the Cox proportional hazards model, respectively.
The 5-year OS (overall survival) rate of patients who were anemia and no-anemia before treatment were 89.1%, and 80.7% (P = 0.01), respectively. The 5-year DMFS (distant metastasis-free survival) rate of patients who were anemia and no-anemia before treatment were 88.9%, and 78.2% (P = 0.01), respectively. The 5-year OS rate of patients who were anemia and no-anemia during treatment were 91.7% and 83.3% (P = 0.004). According to multivariate analysis, the pre-treatment Hb level predicted a decreased DMFS (P = 0.007, HR = 2.555, 95% CI1.294-5.046). Besides, the mid-treatment Hb level predicted a decreased OS (P = 0.013, HR = 2.333, 95% CI1.199-4.541).
Hemoglobin level is a useful prognostic factor in NPC patients receiving IMRT. It is important to control the level of hemoglobin both before and during chemoradiotherapy.
[Show abstract][Hide abstract] ABSTRACT: Metastasis is the major cause of treatment failure in patients with nasopharyngeal carcinoma (NPC). However, the molecular mechanisms of NPC metastasis are poorly understood. Here, using our customized gene microarray containing all of the known human transcription factors and the current markers for epithelial-mesenchymal transition, we report that TEL2 was down-regulated in highly metastatic NPC cells and the metastatic tissues in lymph node. Mechanistically, TEL2 inhibits the cell migration and invasion in vitro and metastasis in vivo by releasing its direct suppression on the SERPINE1 promoter in NPC. Consistently, an inverse correlation was observed between the protein levels of TEL2 and SERPINE1 using clinical NPC samples. Collectively, we have provided the first evidence that TEL2 plays a key role in NPC metastasis by directly down-regulating SERPINE1, and that this novel axis of TEL2 / SERPINE1 may be valuable to develop new strategies for treating NPC patients with metastasis.
[Show abstract][Hide abstract] ABSTRACT: Purpose: To explore the prognostic value of the plasma load of Epstein-Barr viral (EBV) DNA and the tumor response to neoadjuvant chemotherapy (NACT) in advanced-stage nasopharyngeal carcinoma (NPC). Patients and Methods: In all, 185 consecutive patients with stage III to IVb NPC treated with NACT followed by concurrent chemoradiation therapy (CCRT) were prospectively enrolled. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included locoregional relapseefree survival (LRFS) and distant metastasisefree survival (DMFS). Results: EBV DNA was detected in 165 (89%) patients before treatment but was undetectable in 127 (69%) patients after NACT. Detectable EBV DNA levels after NACT were correlated with poor prognosis (3-year PFS 71.8% vs 85.2%, PZ.008 and 3-year DMFS 82.5% vs 92.3%, PZ.013). An unsatisfactory tumor response (stable disease or disease progression) after NACT was also correlated with poor clinical outcome (3- year PFS 71.1% vs 85.9%, PZ.005 and 3-year LRFS 82.7% vs 93.5%, PZ.012). Multivariate analysis showed that the EBV DNA level after NACT (hazard ratio [HR] 2.31, 95% CI 1.18-4.54, PZ.015) and the tumor response to NACT (HR 2.84, 95% CI 1.42-5.67, PZ.003) were both significant prognostic factors for PFS. Multivariate analysis also showed that EBV DNA after NACT was the only significant predictor of DMFS (HR 2.99, 95% CI 1.25-7.15, PZ.014) and that tumor response to NACT was the only significant predictor of LRFS (HR 3.31, 95% CI 1.21-9.07, PZ.020). Conclusion: Detectable EBV DNA levels and an unsatisfactory tumor response (stable disease or disease progression) after NACT serve as predictors of poor prognosis for patients with advanced-stage NPC. These findings will facilitate further risk stratification, early treatment modification, or both before CCRT.
No preview · Article · Aug 2015 · International journal of radiation oncology, biology, physics
[Show abstract][Hide abstract] ABSTRACT: The expansion of myeloid-derived suppressor cells (MDSCs) is a common feature of cancer, but its biological roles and molecular mechanism remain unclear. Here, we investigated a molecular link between MDSC expansion and tumor cell metastasis in nasopharyngeal carcinoma (NPC). We demonstrated that MDSCs expanded and were positively correlated with the elevated tumor COX-2 expression and serum IL-6 levels in NPC patients. Importantly, COX-2 and MDSCs were poor predictors of patient disease-free survival (DFS). Knocking down tumor COX-2 expression hampered functional TW03-mediated-MDSC cell (T-MDSC) induction with IL-6 blocking. We identified that T-MDSCs promoted NPC cell migration and invasion by triggering the epithelial-mesenchymal transition (EMT) on cell-to-cell contact, and T-MDSCs enhanced tumor experimental lung metastasis in vivo. Interestingly, the contact between T-MDSCs and NPC cells enhanced tumor COX-2 expression, which subsequently activated the β-catenin/TCF4 pathway, resulting in EMT of the cancer cells. Blocking transforming growth factor β (TGFβ) or inducible nitric oxide synthase (iNOS) significantly abolished the T-MDSC-induced upregulation of COX-2 and EMT scores in NPC cells, whereas the administration of TGFβ or L-arginine supplements upregulated COX-2 expression and EMT scores in NPC cells. These findings reveal that COX-2 is a key factor mediating the interaction between MDSCs and tumor cells, suggesting that the inhibition of COX-2 or MDSCs has the potential to suppress NPC metastasis.
[Show abstract][Hide abstract] ABSTRACT: Nasopharyngeal carcinoma (NPC) is a common malignancy in southern China and Southeast Asia. NPC frequently metastasizes to the bone in advanced patients resulting in high mortality. The molecular mechanisms for NPC development and cancer-induced bone lesions are unclear. In this study, we firstly determined chemokine receptor CCR2 and CXCR6 expressions in clinical specimens and CNE2, SUNE1, CNE1, and HK1 cell lines. Then, we measured chemokine CCL2 and CXCL16 production in these NPC cell lines by ELISA. Expression levels of these chemokines and their receptors were observed to positively correlate with tumor aggressiveness. Furthermore, U0126 (MEK inhibitor) was used to treat these NPC cell lines. CCL2 and CXCL16 expression levels and cell proliferation were significantly inhibited by U0126 in a dose- and time-dependent manner. Finally, we collected conditioned medium (CM) from NPC cell cultures in the presence of U0126 treatment. When mouse bone marrow non-adherent cells were treated with the CM, the numbers of multinucleated osteoclast formation were dramatically diminished. These results indicate that MEK inhibitor diminishes NPC cell proliferation and NPC-induced osteoclastogenesis via modulating CCL2 and CXCL16 expressions. This study provides novel therapeutic targets such as CCL2/CCR2 and CXCL16/CXCR6 for advanced NPC patients.