BackgroundPathological angiogenesis plays an essential role in tumor aggressiveness and leads to unfavorable prognosis. The aim of this study is to detect the potential role of Retinoblastoma binding protein 2 (RBP2) in the tumor angiogenesis of non-small cell lung cancer (NSCLC).MethodsImmunohistochemical staining was used to detect the expression of RBP2, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and CD34. Two pairs of siRNA sequences and pcDNA3-HA-RBP2 were used to down-regulate and up-regulate RBP2 expression in H1975 and SK-MES-1 cells. An endothelial cell tube formation assay, VEGF enzyme-linked immunosorbent assay, real-time PCR and western blotting were performed to detect the potential mechanisms mediated by RBP2 in tumor angiogenesis.ResultsOf the 102 stage I NSCLC specimens analyzed, high RBP2 protein expression is closely associated with tumor size (P = 0.030), high HIF-1α expression (P = 0.028), high VEGF expression (P = 0.048), increased tumor angiogenesis (P = 0.033) and poor prognosis (P = 0.037); high MVD was associated with high HIF-1α expression (P = 0.034), high VEGF expression (P = 0.001) and poor prognosis (P = 0.040). Multivariate analysis indicated that RBP2 had an independent influence on the survival of patients with stage I NSCLC (P = 0.044). By modulating the expression of RBP2, our findings suggested that RBP2 protein depletion decreased HUVECs tube formation by down-regulating VEGF in a conditioned medium. RBP2 stimulated the up-regulation of VEGF, which was dependent on HIF-1α, and activated the HIF-1α via phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Moreover, VEGF increased the activation of Akt regulated by RBP2.ConclusionsThe RBP2 protein may stimulate HIF-1α expression via the activation of the PI3K/Akt signaling pathway under normoxia and then stimulate VEGF expression. These findings indicate that RBP2 may play a critical role in tumor angiogenesis and serve as an attractive therapeutic target against tumor aggressiveness for early-stage NSCLC patients.

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is a novel oncogene, which has been indicated to be dramatically overexpressed in various malignant tumors. The aims of this study were to detect LAPTM4B protein expression in patients with non-small cell lung cancer (NSCLC) and then analyze the relationships of LAPTM4B protein with clinicopathologic factors, tumor angiogenesis and prognosis with SPSS statistical software. Immunohistochemistry was used to examine the expression of LAPTM4B and CD34 proteins in NSCLC tissues, and its results showed that LAPTM4B protein expression in NSCLC tissues was significantly higher than that in normal lung tissues (P < 0.001). Of the186 NSCLC cases, 129 (69.35 %) had strong expression of LAPTM4B protein, which was associated with histopathologic differentiation (P = 0.017), lymph node metastasis (P = 0.001) and TNM stage (P = 0.046), as well as the microvessel density (MVD) (P = 0.019). Kaplan-Meier survival analysis revealed that patients with strong LAPM4B protein expression and high MVD might have poor overall survival (OS; P = 0.001, P = 0.002, respectively) and disease-free survival (DFS; P = 0.002, P = 0.038, respectively). Multivariate analysis demonstrated that LAPTM4B protein was an independent prognostic marker for OS and DFS of NSCLC patients (P = 0.037, P = 0.046, respectively). These findings illustrated that LAPTM4B protein was closely associated with NSCLC progression, angiogenesis and poor prognosis, suggesting that LAPTM4B protein could be applied not only in predicting patient's outcome, but also in antiangiogenic therapy as a possible novel target molecule.

Studies have shown that genetic activation of TFIIB-related factor 2 (BRF2) represents a unique mechanism of tumorigenesis through the increase in Pol III-mediated transcription. Several studies have shown that BRF2 is overexpressed in several types of cancer and suggest the oncogenic role of BRF2. This study aimed to examine the expression of TFIIB-related factor 2 (BRF2) in patients with esophageal squamous cell cancer (ESCC) and explore the relationship of BRF2 expression with clinicopathologic factors, tumor angiogenesis and prognosis. We found that increased BRF2 protein expression was prevalent in esophageal squamous cell cancer and was significantly associated with deeper tumor invasion (P = 0.039) and microvessel density (P = 0.007). Additionally, expression of BRF2 was found to be an independent prognostic factor in ESCC patients. Furthermore, a significant correlation between high BRF2 expression and shorter overall survival time was found in different subgroups of ESCC patients stratified by the clinical stage, T classification and lymph node metastasis. High expression of BRF2 protein is closely associated with tumor progression and angiogenesis and poor survival of ESCC. BRF2 is a promising biomarker to identify individuals with poor prognostic potential and concludes the possibility of its use as a prognostic marker in patients with ESCC.

Lung cancer is the leading cause of cancer-related mortality all over the world. In recent years, pulmonary adenocarcinoma has surpassed squamous cell carcinoma in frequency and is the predominant form of lung cancer in many countries. Epidemiological investigations have shown an inverse relationship between garlic (Allium sativum) consumption and death rate from many cancers. Diallyl trisulfide (DATS) is one of the garlic-derived compounds (also known as: organosulfer compounds, OSC). DATS can induce apoptosis and inhibit the growth of many cancer cell lines. Our study demonstrated that the apoptotic incidents induced by DATS were a mitochondria-dependent caspase cascade through a significant decrease of the anti-apoptotic Bcl-2 that resulted in up-regulation of the ratio of Bax/Bcl-2 and the activity of caspase-3, -8, and -9. Eventually, DATS induced the apoptosis and inhibited the proliferation in a concentration- and time-dependent manner. Furthermore, by establishing an animal model of female BALB/c nude mice with A549 xenografts, we found that oral gavage of DATS significantly retarded growth of A549 xenografts in nude mice without causing weight loss or any other side effects compared with the control group. All the evidence both in vitro and in vivo suggested that DATS could be an ideal anti-cancer drug.

The nuclear receptor coactivator 5 (NCOA5) was a unique coactivator independent of AF2 that can modulate ERα-mediated transcription. Recent researches have indicated that its downregulation may participate in cancer development and progression. The aims of the present study were to investigate NCOA5 expression in esophageal squamous cell carcinoma (ESCC) and validate its possible influence on patients' prognosis. NCOA5 expression was examined by immunohistochemical staining in 119 ESCC patients' tissues. Ten paired tumor and adjacent normal specimens were examined by Western blot analysis. Statistical analysis was performed to assess its relevance with various clinicopathologic features and its influence on patients' survival. By immunohistochemistry analysis, NCOA5 expression was found to be significantly correlated with differentiation (P = 0.039), T status (P = 0.047) and stage (P = 0.036). Furthermore, we found NCOA5 higher expression in normal tissues than in tumor tissues by Western blot analysis. Univariate analysis showed that poor differentiation (P = 0.035, P = 0.027), lymph node metastasis (P < 0.001, P < 0.001), high T status (P = 0.010, P = 0.012), advanced stage (P < 0.001, P < 0.001) and NCOA5 low expression (P < 0.001, P < 0.001) were significantly correlated with poor prognosis of both disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that NCOA5 low expression (P = 0.019, P = 0.047), high T status (P = 0.015, P = 0.012), lymph node metastasis (P = 0.040, P = 0.021) and advanced stage (P = 0.017, P = 0.046) were independent prognostic factors of poor DFS and OS. Our findings suggest that NCOA5 low expression is associated with ESCC progression and is a potential biomarker in predicting poor prognosis. Further studies of NCOA5 may help develop new therapeutic strategies against ESCC.