Hairy gene homolog increases nasopharyngeal carcinoma cell stemness by upregulating Bmi-1.

B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) is overexpressed in various cancer types. We found that Bmi-1 mRNA levels were elevated in nasopharyngeal carcinoma (NPC) cell lines. In immunohistochemical analyses, high Bmi-1 levels were observed in not only 5 of 38 non-cancerous nasopharyngeal squamous epithelial biopsies, but also in 66 of 98 NPC specimens (67.3%). High Bmi-1 levels were detected more frequently in T3-T4, N2-N3 and stage III-IV NPC biopsies than in T1-T2, N0-N1 and stage I-II NPC samples, indicating that Bmi-1 is upregulated in advanced NPC. In 5-8F and SUNE1 NPC cells, stable depletion of Bmi-1 using lentiviral RNA interference greatly suppressed cell proliferation, induced G1-phase cell cycle arrest, reduced cell stemness and suppressed cell migration and invasion. Likewise, knocking down Bmi-1 inhibited NPC cell growth in nude mice. Both chromatin immunoprecipitation and Western blotting assays demonstrated that Hairy gene homolog (HRY) upregulated Bmi-1 by binding to its promoter, thereby increasing the stemness of NPC cells. Immunohistochemistry and quantitative real-time PCR analyses revealed that HRY expression correlated positively with Bmi-1 expression in a cohort of NPC biopsies. These findings suggested that HRY promotes NPC cell stemness by upregulating Bmi-1, and that silencing Bmi-1 can suppress NPC progression.

[Correlation of CD4+CD29+ regulatory T cells with recurrence and survival time in patients with non-small cell lung cancer].

OBJECTIVE: To investigate the correlation of CD4+CD29+ regulatory T cells (Treg) with tumor recurrence and survival time in patients with non-small cell lung cancer (NSCLC). METHODS: Fifty-nine patients with NSCLC treated with radical surgery were followed up for 5 years. Blood Treg cells were examined during the follow-up using flow cytometry (FCM). The sensitivity and specificity of Treg cells to predict recurrence of NSCLC were analyzed using receiver-operating characteristic (ROC) curve and compared with those of carcinoembryonic antigen (CEA) and cytokeratin21-1 (Cyfra21-1). The influences of gender, age, occupation and radiotherapy on survival time of the patients were analyzed with Kaplan-Meier method. RESULTS: Among the 59 patients, the shortest survival time was 23 months while the longest time was over 67 months. Nineteen patients had NSCLC recurrence, and 17 (28.81%) of them died of metastasis during the follow-up. The frequencies of blood Treg cells in patients who did not receive radiotherapy and in patients with tumor recurrence were significantly higher than those in patients receiving radiotherapy and in patients free of recurrence (P=0.000). ROC curves showed that the area under curve (AUC) lowered in the order of Treg cells, Cyfra21-1, CEA (P=0.002, 0.006 and 0.013, respectively) with 95% confidence interval (CI) of 0.649-0.981, 0.621-0.936 and 0.584-0.944, respectively. At the cut-off value of 7.53%, the sensitivity and specificity of Treg cells to predict NSCLC recurrence was 91.42% and 87.59%, respectively. The five-year survival rate of the 59 patients was 71.18% (42/59), and Kaplan-Meier analysis revealed a longer survival time in female patients (P=0.038), in patients below 50 years of age (P=0.013), in patients not engaging in mental work (P=0.029), and in patients receiving radiotherapy (P=0.003). CONCLUSION: Treg cells has a better efficiency than Cyfra21-1 and CEA to predict tumor recurrence in patients with NSCLC following radical surgery. The male gender, an age beyond 50 years, an occupation of mental work, and failure to receive radiotherapy are all risk factors for recurrence of NSCLC.

MMP-14 overexpression correlates with poor prognosis in non-small cell lung cancer.

Matrix metalloproteinase-14 (MMP-14) has been demonstrated to play an important role in tumor progression. The aim of this study was to analyze the correlation between MMP-14 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). Immunohistochemical staining for MMP-14 protein was performed in 104 patients with NSCLC. High levels of MMP-14 protein were positively correlated with the status of clinical stage (I-II vs. III-IV; P < 0.001), N classification (N0-N1 vs. N2-N3; P < 0.001), distant metastasis (no vs. yes; P = 0.014), and differentiated degree (high vs. low or undifferentiated; P = 0.001). The patients with higher MMP-14 expression of protein had shorter survival time than patients with low MMP-14 expression. Multivariate analysis indicated that the level of MMP-14 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with NSCLC. In conclusion, MMP-14 is a potential unfavorable prognostic factor for patients with NSCLC.

Neoplastic spindle cells in nasopharyngeal carcinoma show features of epithelial-mesenchymal transition.

AIM: To investigate whether the neoplastic spindle cells in nasopharyngeal carcinoma (NPC) are associated with the process of epithelial-mesenchymal transition (EMT). METHODS AND RESULTS: We used immunohistochemistry to analyse the expression of cytokeratin, E-cadherin, ß-catenin, vimentin, fibronectin, Snail1, Slug and aldehyde dehydrogenase 1 (ALDH1) in 115 cases of NPC in which there were neoplastic spindle cells; in 47 cases a neoplastic squamous cell component was also present. There was no significant difference in the expression of cytokeratin observed in the neoplastic spindle cells (P = 0.644), compared to the squamous component whereas E-cadherin expression was reduced. By contrast, the expression of ß-catenin, vimentin, fibronectin, Snail1, Slug and ALDH1 was up-regulated in the spindle cells (all P = 0.000). Furthermore, E-cadherin expression was associated negatively with ß-catenin (P < 0.001), vimentin (P < 0.001), fibronectin (P < 0.001), Slug (P < 0.001) and ALDH1 (P < 0.001) in neoplastic spindle cells, but did not correlate with Snail1 expression (P = 0.093). CONCLUSIONS: Our findings demonstrate for the first time that EMT might play an important role in the development of neoplastic spindle cells in NPC.

Nuclear expression of N-cadherin correlates with poor prognosis of nasopharyngeal carcinoma.

AIMS: To investigate the aberrant expression of N-cadherin in nasopharyngeal carcinoma (NPC) and its prognostic significance. METHODS AND RESULTS: Immunohistochemical staining for N-cadherin protein was performed on tissue microarray (TMA) from 122 NPC patients. Cytoplasmic N-cadherin was observed in 42.6% and nuclear N-cadherin in 45.1% of NPC tissues. High expression of cytoplasmic and nuclear N-cadherin was associated with a majority of the clinicopathological variables, including lymph node metastasis, distant metastasis and clinical stage. Cytoplasmic N-cadherin was associated positively with nuclear N-cadherin expression (P = 0.000). In univariate analysis, cytoplasmic N-cadherin showed no significant impact on patient prognosis. In contrast, the overall survival was significantly shorter in patients with high nuclear N-cadherin than those with low levels of staining (P = 0.002). A high expression of nuclear N-cadherin predicted poorer survival in patients with late stage disease (P = 0.033), but not those with early tumour stage. In addition, multivariate analysis showed nuclear N-cadherin to bean independent prognostic marker for NPC patients (P = 0.024). CONCLUSIONS: Nuclear N-cadherin expression may represent a valuable prognostic marker in NPC patients, especially those with late stage disease.