Zhixiong Yang

Increased expression of MMP9 is correlated with poor prognosis of nasopharyngeal carcinoma

IntroductionThe aim of the present study was to analyze the expression of matrix metalloproteinase 9 (MMP9) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including the survival of patients with NPC.MethodsUsing real-time PCR, we detected the mRNA expression of MMP9 in normal nasopharyngeal tissues and nasopharyngeal carcinoma (NPC) tissues. Using immunohistochemistry analysis, we analyzed MMP9 protein expression in clinicopathologically characterized 164 NPC cases (116 male and 48 female) with age ranging from 17 to 80 years (median = 48.4 years) and 32 normal nasopharyngeal tissues. Cases with greater than or equal to 6 and less than 6 of 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.ResultsThe expression level of MMP9 mRNA was markedly greater in NPC tissues than that in the nasopharyngeal tissues. Immunohistochemical analysis revealed that the protein expression of MMP9 detected in NPC tissues was higher than that in the nasopharyngeal tissues (P = 0.004). In addition, high levels of MMP9 protein were positively correlated with the status of lymph node metastasis (N classification) (P = 0.002) and clinical stage (P < 0.001) of NPC patients. Patients with higher MMP9 expression had a significantly shorter overall survival time than did patients with low MMP9 expression. Multivariate analysis suggested that the level of MMP9 expression was an independent prognostic indicator (P = 0.008) for the survival of patients with NPC.ConclusionHigh level of MMP9 expression is a potential unfavorable prognostic factor for patients with NPC.

Aldehyde dehydrogenase 1, a functional marker for identifying cancer stem cells in human nasopharyngeal carcinoma

Aldehyde dehydrogenase 1 (ALDH1) activity has now been employed successfully as a cancer stem cells (CSCs) marker in various tumors. We wanted to investigate whether ALDH1 can be used as a putative CSCs marker and a powerful prognostic factor in nasopharyngeal carcinoma (NPC). Here, we isolated ALDH1-positive cells from human NPC cell lines (5-8F and CNE2) and found that ALDH1-positive cancer cells grew faster and had higher clone formation efficiency (0.435±0.15; 0.431±0.025 vs. 0.131±0.007; 0.121±0.126), differentiation capability and had higher migration (233.00±5.29; 228.60±9.34 vs. 123.20±7.70 vs. 97.20±6.61) than those of ALDH1-negative cancer cells in vitro. In addition, ALDH1- positive cancer cells formed significantly more tumor spheres. Our in vivo experiments showed that only 5×10(3) ALDH1-positive NPC cells were required to induce tumors. Notably, ALDH1-positive cells are enriched in the side-population (SP) cells, and stem cells-like genes OCT4, BMI1, KLF4 and SOX2 are preferentially expressed in ALDH1-positive cells. Immunohistochemical results showed that the expression of ALDH1 correlated significantly with T classification (P=0.011), N classification (P=0.005), M classification (P=0.002) and clinical stage (P=0.001). Interestingly, ALDH1 expression in the tumor correlated significantly with epithelial-mesenchymal transition (EMT) markers including vimentin expression and loss of E-cadherin (P=0.003 and 0.008, respectively). Furthermore, multivariate analyses showed that ALDH1 expression was an independent prognostic indicator (P=0.032). Taken together, for the first time, we demonstrate that ALDH1 could be a novel stem cells marker and a valuable predictor of poor survival NPC.

Elevated expression of CDK4 in lung cancer.

BackgroundThe 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.MethodsUsing 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.ResultsThe 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 p21ConclusionOverexpressed CDK4 is a potential unfavorable prognostic factor and mediates cell cycle progression by regulating the expression of p21 in lung cancer

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.

Let-7a inhibits migration, invasion and epithelial-mesenchymal transition by targeting HMGA2 in nasopharyngeal carcinoma

BackgroundLet-7a has been shown to play important roles in nasopharyngeal carcinoma (NPC) cell proliferation and apoptosis, but little is known about the function and mechanism of let-7a in nasopharyngeal carcinoma metastasis. We aimed to investigate the function and mechanism of let-7a in nasopharyngeal carcinoma metastasis and clarified the regulation of high mobility group A2 (HMGA2) by let-7a.MethodsThe expression levels of let-7a and HMGA2 were examined in NPC clinical specimens using quantitative reverse transcription-PCR (RT-qPCR). HMGA2 was confirmed as a target of let-7a through luciferase reporter assays, RT-qPCR, and Western blotting. Furthermore, the roles of let-7a and HMGA2 in regulating NPC cells biological properties including proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process were analyzed with let-7a mimics and si-HMGA2 transfected cells.ResultsOur study demonstrated that let-7a was downregulated and inversely associated with the clinical stage, T classification and N classification, and HMGA2 was upregulated and directly associated with the clinical stage and N classification in patients with NPC. Moreover, there was an inverse correlation between let-7a expression and HMGA2 expression in NPC patient. In addition, HMGA2 was negatively regulated at the posttranscriptional level by let-7a via a binding site of HMGA2-3′UTR. In addition, synthetic let-7a mimics suppressed NPC cells migration, invasion and EMT process and knockdown of HMGA2 was consistent with the effects of let-7a in NPC cells.ConclusionLet-7a directly downregulates HMGA2 protein expression, which suppress NPC cell migration, invasion and EMT process. Let-7a could serve as a potential diagnostic marker and therapeutic target for NPC.

Down-regulation of miR-133a as a poor prognosticator in non-small cell lung cancer.

miR-133a has been demonstrated to play an important role in tumor progression. The aim of present study was to analyze the correlation between miR-133a expression level and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). The expression of miR-133a in 104 pairs of human lung cancer tissues and adjacent normal lung tissues were analyzed by qRT-PCR. Here we show that miR-133a was down-regulated in NSCLC. The levels of miR-133a were negatively correlated with the status of N classification (N0-N1 vs. N2-N3, P=0.000), clinical stage (I-II vs. III-IV, P=0.010) and MMP-14 expression (High vs. Low, P=0.012). The patients with low miR-133a expression had shorter survival time than those with high miR-133a expression. Multivariate analysis indicated that the level of miR-133a expression was an independent prognostic indicator (P=0.012) for the survival of patients with NSCLC. In conclusion, decreased expression of miR-133a might be a potential unfavorable prognostic factor for patients with NSCLC, and further studies would be needed to prove our findings.

LATS2 as a poor prognostic marker regulates non-small cell lung cancer invasion by modulating MMPs expression

Large tumor suppressor 2 (LATS2) plays significant roles in tumorigenesis and cancer progression. This study was aimed to analyze the correlation between LATS2 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). LATS2 expression was examined in 73 NSCLC clinical specimens and 22 normal lung tissues using immunohistochemistry. Low levels of LATS2 protein were inversely associated with the T classification (P=0.001), N classification (P=0.005) and clinical stage (P=0.001) in NSCLC patients. Patients with lower LATS2 expression had a significantly shorter overall survival than patients with high LATS2 expression. Multivariate analysis suggested that low expression of LATS2 was an independent prognostic indicator (P=0.002) for the survival of patients with NSCLC. Furthermore, overexpression of LATS2 resulted in mobility inhibition in NSCLC cell lines A549 and H1299, and reduced protein level of matrix metalloproteinase-2 (MMP-2) and MMP-9. On the contrary, LATS2 siRNA treatment enhanced cell mobility and increased MMP-2 and MMP-9 protein expression level. In conclusion, low expression of LATS2 is a potential unfavorable prognostic factor and promoted cell invasion and migration in NSCLC.

High-mobility group A2 overexpression is an unfavorable prognostic biomarker for nasopharyngeal carcinoma patients

Our previous study showed that knockdown of high-mobility group A2 (HMGA2) could suppress nasopharyngeal carcinoma (NPC) cell migration, invasion, and epithelial–mesenchymal transition (EMT) process, and HMGA2 is a direct functional target of let-7 to regulate NPC cell migration, invasion, and EMT process. However, little is known about the clinical and prognostic significance of HMGA2 protein in NPC patients. The purpose of this study is to identify the clinical and prognostic roles of HMGA2 in NPC patients. We initially analyzed the microarray data and verified mRNA and protein levels of HMGA2 in NPC tissues. Immunohistochemical staining for HMGA2 protein was performed in 116 NPC patients. The associations between HMGA2 protein expression and clinicopathologic features and its prognostic significance were analyzed. In our results, we found mRNA and protein expressions of HMGA2 were upregulated in NPC tissues and cell lines. In 116 NPC tissue samples, we observed that HMGA2 protein overexpression was associated with clinical stage, lymph node metastasis, and distant metastasis. Moreover, NPC patients with high levels of HMGA2 protein expression had shorter overall survival in comparison to patients with low levels of HMGA2 protein. In multivariate analysis, HMGA2 protein overexpression was an unfavorable prognostic factor for NPC patients. In conclusion, HMGA2 is an important biomarker to predicting NPC patient’s survival time.

Low expression of olfactomedin 4 correlates with poor prognosis in smoking patients with non-small cell lung cancer.

Olfactomedin 4 (OLFM4) has been demonstrated to serve an important function in tumor progression. This study aims to analyze the correlation between OLFM4 expression and clinicopathological features and the prognostic significance of OLFM4 in the context of smoking status of non-small cell lung cancer (NSCLC) patients. A total of 218 NSCLC patients, who were histopathologically diagnosed from 2001 to 2013, were reviewed in the study. OLFM4 expression was analyzed by immunohistochemical staining of tissue samples. The association of OLFM4 with clinicopathological parameters was evaluated. Overall survival and disease-specific survival were evaluated by Kaplan-Meier survival analysis. Immunohistochemical analyses showed that OLFM4 was highly expressed in 64.2% of NSCLC patients. OLFM4 expression level in NSCLC lesions was strongly correlated with pathologic grade (P = .017), lymph node metastasis (P = .012), peritumor intravascular cancer emboli (P = .03), and smoking status (P < .001). Kaplan-Meier survival curves showed that, among smoking patients, those with low OLFM4 expression had shorter survival time (overall survival and disease-specific survival) than those with high OLFM4 (P < .05). Conclusively, although low OLFM4 expression is not an independent prognostic biomarker, it might indicate worse prognosis for smoking patients with NSCLC, thereby identifying patients who might benefit from targeting OLFM4 therapy.

MiR-373-3p Promotes Invasion and Metastasis of Lung Adenocarcinoma Cells

BACKGROUND AND OBJECTIVE Lung cancer is the leading cause of cancer-related deaths worldwide, and metastasis is the major cause of death in lung cancer patients. MiR-373 is closely associated with invasion and metastasis in other tumor cells. This study explored the expression of miR-373-3p in non-small cell lung cancer (NSCLC) and its effect on the invasive and metastatic capabilities of lung adenocarcinoma cells, as well as their mechanisms of action. METHODS The expression of miR-373-3p in NSCLC tissues and lung adenocarcinoma cell lines was detected by quantitative reverse transcription polymerase chain reaction. The roles of miR-373-3p in regulating lung adenocarcinoma cell invasion and metastatic properties were analyzed with miR-373-3p mimic/inhibitor-transfected cells via Transwell chamber assay. Matrix metalloproteinase MMP-9 and MMP-14 protein levels were detected by Western blot in lung cancer cells after transfection. RESULTS MiR-373-3p was upregulated in 51 NSCLC tissues and 5 NSCLC cell lines. Gain-of-function and loss-of-function studies showed that overexpression of miR-373-3p promoted H1299 cell migration and invasion, which resulted in upregulation of MMP-9 and MMP-14. By contrast, miR-373-3p knockdown inhibited these processes in A549 cells and downregulated the expression of MMP-9 and MMP-14. CONCLUSIONS Our results demonstrated that miR-373-3p participated in the invasion and metastasis of lung adenocarcinoma cells, partly by upregulation of MMP-9 and MMP-14.