Prognostic value of circulating tumor cells and its association with the expression of cancer stem cells in nasopharyngeal carcinoma patients.

The release of circulating tumor cells (CTCs) into vasculature is an early event in the metastatic process and the detection of CTCs has been widely used clinically. In addition, cancer stem cells (CSCs) are the source of distant metastasis. However, the relationship between CTCs and CSCs in nasopharyngeal carcinoma (NPC) patients was largely unknown. A total of 93 NPC patients were enrolled in this study. The CTCs in the peripheral blood were detected. The expression of ALDH1A1 in the tumor tissues of the corresponding patients was detected using immunohistochemistry (IHC). The prognostic value of CTCs level and the correlation with the expression of ALDH1A1 was evaluated. Data showed that the detection of CTCs was positively correlated with metastasis (p<0.001). The positive detection of CTCs was also associated with poor overall survival (p=0.025). CTCs ≥2 demonstrated good specificity and sensitivity in predicting distant metastasis, while CTCs ≥8 demonstrated better specificity and sensitivity in predicting prognosis than CTCs ≥2. Furthermore, we found that there was a positive relationship between the detection of CTCs and the expression of ALDH1A1 (p=0.001). The prognosis analysis also demonstrated that high ALDH1A1 expression was correlated with poor overall survival (p=0.006). Our study demonstrated a positive correlation between the CTCs and the expression of CSCs, both were positively correlated with metastasis and poor prognosis. These results indicated that the CTCs might indirectly reflect the expression of CSCs.

Comparison of immunological characteristics between paired mismatch repair-proficient and -deficient colorectal cancer patients.

BACKGROUND: Currently, mismatch repair-deficient (dMMR) status is a promising candidate for targeted immune checkpoint inhibition therapy in colorectal cancer (CRC) patients, however, the potential immunological mechanism has not yet been well clarified and some other predictors need to be excavated as well. METHODS: We collected 330 CRC patients by the match of mismatch repair-proficient (167) and dMMR (163), explored the relationship between MMR status and some important immune molecules including MHC class I, CD3, CD4, CD8, CD56, programmed death-1 and programmed death ligand-1, and investigated the risk factors for dMMR status as well as low MHC class I expression. The Pearson Chi square test was used for analyzing the associations between clinicopathological and immune characteristics and MMR status, and two categories logistic regression model was used for univariate and multivariate analysis to predict the odds ratio of risk factors for dMMR status and low MHC class I expression. RESULTS: Multivariate logistic regression analysis showed that low MHC class I and CD4 expression and high CD8 expression were significant risk factors for dMMR status [odds ratio (OR) = 24.66, 2.94 and 2.97, respectively; all p < 0.05] and dMMR status was the only risk factor for low MHC class I expression (OR = 15.34; p < 0.001). CONCLUSIONS: High CD8 and low MHC class I expression suggests the contradiction and complexity of immune microenvironment in dMMR CRC patients. Some other immunocytes such as CD56+ cells might also participate in the process of immune checkpoint inhibition, whereas needs further investigations.

Zoledronic acid exerts antitumor effects in NB4 acute promyelocytic leukemia cells by inducing apoptosis and S phase arrest.

The aim of this study was to investigate the antitumor effect of zoledronic acid (ZOL) in the NB4 human acute promyelocytic leukemia (APL) cell line and explore the potential mechanism of action of this compound. NB4 cells were exposed to various concentrations (0-200µM) of ZOL. Cell viability was measured by MTS assay. The extent of cell apoptosis and distribution of cells in the different phases of the cell cycle were analyzed with flow cytometry. The expression of apoptosis- and cell cycle-related proteins was assayed by Western blot. The combined effect of ZOL and arsenic trioxide (ATO) on the proliferation of NB4 cells was also determined. The results of this study indicate that ZOL inhibits cell proliferation in a time- and dose-dependent fashion and also induces apoptosis and S phase arrest in a dose-dependent manner. The Western blot analysis confirmed the induction of apoptosis and S phase arrest, revealing that the pro-apoptosis proteins Bax, Puma and activated caspase-9 were upregulated and the anti-apoptosis proteins Bcl-2 and Bcl-xL were downregulated. ZOL at a concentration of 50µM synergized with 0.5µM ATO on the growth inhibition of NB4 cells. Taken together, our data indicate that ZOL exerts a potent antitumor effect on NB4 cells by inducing apoptosis and cell cycle arrest, and that ZOL can synergize with the traditional chemotherapy drug ATO.

miR-148b functions as a tumor suppressor in non-small cell lung cancer by targeting carcinoembryonic antigen (CEA).

Aberrant expression of miR-148b has been found in several types of cancer, but its expression and potential biologic role in non-small cell lung cancer (NSCLC) are still largely unknown. Here, we found that miR-148b was commonly under-expressed in human non-small celllung cancer (NSCLC) specimens and cell lines. The overexpression of miR-148b dramatically suppressed NSCLC cell proliferation and migration. Furthermore, miR-148b could regulate carcinoembryonic antigen (CEA) expression by luciferase reporter assay. On the other hand, CEA was widely up-regulated in NSCLC specimens, and its mRNA levels were inversely correlated with miR-148b expression. These suggest that CEA expression may be regulated by miR-148b. Collectively, our findings indicate miR-148b is low expression in NSCLC cells, which results in CEA overexpression and disease progression in NSCLC patients.

MicroRNA-30a promotes invasiveness and metastasis in vitro and in vivo through epithelial-mesenchymal transition and results in poor survival of nasopharyngeal carcinoma patients.

Although microRNA-30a (miR-30a) has been shown to regulate cancer metastasis, the molecular mechanism has not yet been clearly elucidated in nasopharyngeal carcinoma (NPC). The present study was to investigate the miR-30a expression pattern and its potential functions and further to identify its target gene and corresponding clinical applications in NPC. MiR-30a was identified to be down-regulated in NPC primary tumors compared with metastatic tumors using quantitative real-time PCR. Furthermore, over-expression of miR-30a transfected with precursor increased the ability of metastasis and invasion of NPC tumor cells in vivo and in vitro. E-cadherin was screened as a putative target gene of miR-30a by computational algorithms. Luciferase reporter assays showed that over-expression of miR-30a directly reduced the activity of a luciferase transcript combined with the 3'-untranslated region (3'-UTR) of E-cadherin. Kaplan-Meier survival analysis and log-rank test were analyzed for 1077 NPC patients for overall survival, indicating that a high expression of E-cadherin was beneficial for NPC prognosis (P = 0.001). Importantly, NPC patients with high expression of E-cadherin had much lower risk of poor prognosis (hazard ratio = 0.757, P = 0.017) using multivariate analysis. In conclusion, miR-30a could play an important role in regulating NPC metastasis and potentially provide useful guidelines for individualized therapy.

Knockdown of miR-214 promotes apoptosis and inhibits cell proliferation in nasopharyngeal carcinoma.

MicroRNA-214 (MiR-214) is aberrantly expressed in several human tumors such as ovarian cancer and breast cancer. However, the role of miR-214 in nasopharyngeal carcinoma (NPC) is still unknown. In this study, we report that miR-214 was overexpressed in NPC cell lines and tissues. Silencing of miR-214 by LNA-antimiR-214 in NPC cells resulted in promoting apoptosis and suppressing cell proliferation in vitro, and suppressed tumor growth in nude mice in vivo. Luciferase reporter assay was performed to identify Bim as a direct target of miR-214. Furthermore, this study showed that low Bim expression in NPC tissues correlated with poor survival of NPC patients. Taken together, our findings suggest that miR-214 plays an important role in NPC carcinogenesis.

Down-regulation of c9orf86 in human breast cancer cells inhibits cell proliferation, invasion and tumor growth and correlates with survival of breast cancer patients.

C9orf86 which is a novel subfamily within the Ras superfamily of GTPases, is overexpressed in the majority of primary breast tumors. Few functional studies have focused on the C9orf86 protein; therefore, in this study, we explored the role of C9orf86 in breast carcinogenesis. In our study, we found that silencing of C9orf86 by siRNA in MCF-7 and SK-BR-3 cells resulted in suppressed cell proliferation as well as in vitro cell invasion capabilities. Moreover, knockdown of C9orf86 inhibited tumor growth in nude mice. Cell cycle and apoptotic assays showed that the anti-proliferative effect of C9orf86-siRNA was mediated by arresting cells in the G1 phase and promoting apoptosis. In addition, we found that patients with high levels of C9orf86 expression showed a significant trend towards worse survival compared to patients with low C9orf86 expression (P = 0.002). These results provide evidence that C9orf86 represents a novel and clinically useful biomarker for BC patients and plays an important role during the progression of BC.

Elevated DLL4 expression is correlated with VEGF and predicts poor prognosis of nasopharyngeal carcinoma.

Delta-like ligand 4 (DLL4), one of the transmembranous Notch ligands, is upregulated at the site of tumor growth, particularly during tumor angiogenesis. Expression pattern of DLL4 in nasopharyngeal carcinoma (NPC) and the clinical and prognostic significance remain unclear. In this study, immunohistochemical analysis (IHC) was used to examine the protein level of DLL4 in NPC tissues from two independent cohorts. In the testing cohort (311 cases), we applied the X-tile program software able to assess the optimal cutoff points for biomarkers in order to accurately classify patients according to clinical outcome. In the validation cohort (113 cases), the cutoff score derived from X-title analysis was investigated to determine the association of DLL4 expression with disease-specific survival (DFS). Our results showed that high expression of DLL4 was observed in 134 of 313 (42.8 %) in the testing cohort and 58 of 113 (43.6 %) in the validation cohort. High expression of DLL4 independently predicted poorer disease-specific survival, as evidenced by univariate and multivariate analysis (P < 0.05). Moreover, DLL4 expression was significantly elevated in distant NPC metastases relative to primary NPC tumors (P = 0.001). Importantly, we found a significant positive relationship between DLL4 and vascular endothelial growth factor (VEGF) (P < 0.001). Patients with dual elevated DLL4 and VEGF expression displayed a significant overall survival disadvantage compared to those with dual low expression (P < 0.05). These findings provide evidence that high expression of DLL4 serves as an independent predictor of poor prognosis in NPC patients.

MiR-138 suppressed nasopharyngeal carcinoma growth and tumorigenesis by targeting the CCND1 oncogene.

The microRNA miR-138 is dysregulated in several human cancers, but the underlying mechanism remains largely unknown. Here, we report that miR-138 is commonly underexpressed in nasopharyngeal carcinoma (NPC) specimens and NPC cell lines. The ectopic expression of miR-138 dramatically suppressed cell proliferation and colony formation in vitro and inhibited tumorigenesis in vivo. Moreover, we identified the cyclin D1 (CCND1) gene as a novel direct target of miR-138. In consistent with the knocked-down expression of CCND1, overexpression of miR-138 inhibited cell growth and cell cycle progression in NPC cells. Furthermore, CCND1 was widely upregulated in NPC tumors, and its mRNA levels were inversely correlated with miR-138 expression. Taken together, our findings suggest that miR-138 might be a tumor suppressor in NPC, which is exerted partially by inhibiting CCND1 expression. The identification of functional miR-138 in NPC and its direct link to CCND1 might provide good candidates for developing diagnostic markers and therapeutic applications for NPC.

Expression of heat shock protein 70 in nasopharyngeal carcinomas: different expression patterns correlate with distinct clinical prognosis.

BACKGROUND: Heat shock protein 70, a stress protein, has been implicated in tumor progression. However, its role in nasopharyngeal carcinoma (NPC) progression has not yet been clearly investigated. METHODS: Immunohistochemistry (IHC) was employed to examine the expression patterns of Hsp70, human leukocyte antigen -A (HLA-A) in NPC tissue samples. RESULTS: The expression of Hsp70 exhibited different spatial patterns among nuclear, membrane and cytoplasm in 507 NPC tumor tissues. Kaplan-Meier survival analysis demonstrated that different Hsp70 expression patterns are correlated with different patient outcomes. High membranal and cytoplasmic levels of Hsp70 predicted good survival of patients. In contrast, high nuclear abundance of Hsp70 correlated with poor survival. Moreover, the membranal and cytoplasmic levels of Hsp70 were positively correlated with levels of the MHC I molecule HLA-A. CONCLUSIONS: Different Hsp70 expression patterns had distinct predictive values. The different spatial abundance of Hsp70 may imply its important role in NPC development and provide insight for the development of novel therapeutic strategies involving immunotherapy for NPC.