Qun Xue

Vacuolar protein sorting 4B, an ATPase protein positively regulates the progression of NSCLC via promoting cell division

Vacuolar protein sorting 4B (VPS4B), a member of ATPase family proteins, plays a crucial role in lysosome-dependent degradation. Recently, it was found that VPS4B could negatively regulate breast cancer progression through promoting lysosomal-dependent degradation for EGFR. Nevertheless, other studies found that VPS4B was also essential for cell division and mitosis through insuring the maintenance of centrosome and spindle assembly. Thus, the role of VPS4B in cancer biology remains under debate. In this study, we analyzed the clinical significance of VPS4B in NSCLC. The expression of VPS4B was evaluated by Western blot in 8 paired fresh NSCLC tissues and immunohistochemistry on 105 paraffin-embedded slices. VPS4B was highly expressed in NSCLC and significantly associated with NSCLCs tumor size, histological differentiation, clinical stage and Ki-67. Besides, high VPS4B expression was an independent prognostic factor for NSCLC patients’ poor survival. To determine whether VPS4B could regulate the proliferation of NSCLC cells, we knocked down the expression of VPS4B and analyzed the proliferation of A549 NSCLC cells using Western blot, CCK8 and flow cytometry assays, which together indicated that loss of VPS4B could inhibit cell cycle progress. These data suggest that VPS4B may promote the progression of NSCLC and be a biotarget for NSCLCs therapy.

Upregulated expression of ILF2 in non-small cell lung cancer is associated with tumor cell proliferation and poor prognosis

ILF2 (NF45) is a sequence-specific DNA binding protein that is involved in mitosis control, transcriptional regulation, DNA breaks repair, microRNA processing and viral replication. In the present study, we aim to investigate the potential role of ILF2 in the progression of non–small cell lung cancer (NSCLC). Western blot analysis indicated that ILF2 was up-regulated in NSCLC tissues, compared with adjacent non-tumorous ones. Furthermore, immunohistochemistry analysis showed that the expression of ILF2 was correlated with histological differentiation, clinical stage and Ki-67 expression in NSCLC specimens. In addition, using Kaplan–Meier survival analysis, we found that high expression of ILF2 predicted poor outcome in NSCLC patients. Furthermore, we showed that up-regulated expression of ILF2 might play a regulatory role in the proliferation of NSCLC cells using serum starvation and release assay. Moreover, knockdown of ILF2 inhibited cell proliferation and cell cycle progress of NSCLC cells. In conclusion, our results indicated that ILF2 was involved in the pathogenesis of NSCLC and might be a potential target for NSCLC therapy.

Epithelial membrane protein 3 is frequently shown as promoter methylation and functions as a tumor suppressor gene in non-small cell lung cancer

Epithelial membrane protein 3 (EMP3) is a typical member of the epithelial membrane protein (EMP) family which has been reported to be a tumor suppressor gene in neuroblastomas and gliomas and recently reported to be commonly repressed in esophageal squamous cell carcinoma (ESCC) cell lines. However, the expression and clinical significance of EMP3 protein in lung cancer have not yet been elucidated. In this article, we detected that the expression of EMP3 in non-small cell lung cancer was significantly lower than the expression of normal lung tissues (P < 0.01) by western blot. EMP3 expression in Lung cancer was significantly related to p-TNM stage (P < 0.05) and EMP3 was negatively correlated with proliferation marker Ki67(r = -0.775; P < 0.01), However, no significant correlations were found between EMP3 and other clinical parameters. The post-recurrent survival after radical surgery was poorer in lung cancer patients with lower EMP3 expression (P < 0.01). While in vitro, following release from serum starvation of A549 NSCLC cell, the expression of EMP3 was deregulated. Thus, our finding suggests that EMP3 may be a tumor suppressor gene at the late step of lung cancer, and EMP3 may be a potential prognostic marker and therapeutic target of NSCLC.

Overexpression of leucine aminopeptidase 3 contributes to malignant development of human esophageal squamous cell carcinoma

Leucine aminopeptidases (LAPs) were associated with tumor cell proliferation, invasion and/or angiogenesis. We aimed to examine the biological function of LAP3 in esophageal squamous cell carcinoma (ESCC). LAP3 expressions were examined in human ESCC tissue and cell lines ECA109 and TE1 cells. Recombinant pSilencer4.1-LAP3–shRNA was transfected into ECA109 cells to silence LAP3 expression. The effects of LAP3 silencing on ECA109 cell proliferation in vitro were evaluated. Flow cytometry profiling was used to detect the differentiate cell cycle distribution in LAP3-silenced ECA109 cells. Wound-healing assay and transwell assay were used to examine the activities of migration and invasion in LAP3-silenced ECA109 cells. We overexpressed LAP3 in TE1 cells to find out the corresponding results. LAP3 expression level was abundance in ESCC tissue. LAP3 silencing significantly reduced ECA109 cell proliferation and colony formation. The knockdown of LAP3 resulted in cell cycle arrest at G1-phase. Moreover, over expression of LAP3 favors TE1 cell proliferation and invasiveness which also confirms its contribution in malignant development. We came to the conclusion that LAP3 contributed to ESCC progression by overcoming cell cycle arrest. The proliferative and migration effects of LAP3 might contribute to malignant development of human ESCC.

Polycomb Group Oncogene RING1 is Over-expressed in Non-Small Cell Lung Cancer

Ring finger protein 1 (RING1) have recently been reported to be related to aggressive tumor features in Prostate Cancer and urothelial carcinoma of the bladder. However, the role of RING1 in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. So we aimed at investigating the potential role of RING1 in NSCLC. RING1 expression was evaluated by Immunoblot in 8 paired fresh lung cancer tissues and immunohistochemistry on 69 paraffin-embedded sections from 2006 to 2009. Furthermore, flow-cytometry and RNA interference were performed to analyse the role of RING1 in A549 cells. We showed that the expression level of RING1 was significant increased in lung cancer as compared with the adjacent normal tissue. High expression level of RING1 was associated with TNM stage (P = 0.013), and RING1 was positively related with proliferation marker Ki67 (P < 0.05). Moreover, RING1 knockdown induces growth suppression of human lung cancer cells through G1/S cell cycle phase arrest in vitro. Kaplan–Meier survival curves showed that high expression level of RING1 was associated with poor prognosis (P = 0.03). On the basis of these results, we suggested that RING1 protein expression may be a favorable independent prognostic parameter for non-small cell lung cancer.

TAB3 overexpression promotes cell proliferation in non-small cell lung cancer and mediates chemoresistance to CDDP in A549 cells via the NF-κB pathway

Transforming growth factor-activated kinase 1 (TAK1)-binding protein 3 (TAB3) is essential for the activation of the nuclear factor kappa B (NF-κB) pathway and has important roles in cell survival. However, the contribution of TAB3 to non-small cell lung cancer (NSCLC) remains elusive. In the present study, Western blotting and immunohistochemistry assays demonstrated that TAB3 expression was frequently increased in NSCLC tissues and cells. In addition, chi-square test and Kaplan–Meier analysis revealed that upregulation of TAB3 expression correlated with a more invasive tumor phenotype and poor prognosis. In addition, a series of experiments, including serum starvation–refeeding experiment and TAB3-siRNA transfection assay, showed that TAB3 expression promoted NSCLC cell proliferation. Furthermore, the effect of TAB3 expression on the sensitivity to cis-diamminedichloroplatinum (CDDP) and possible signaling transduction pathways was investigated. When the expression of TAB3 was inhibited by siRNA transfection, the sensitivity to CDDP was enhanced. Moreover, it showed that downregulation of TAB3 enhanced CDDP-induced A549 cell apoptosis through the inhibition of the NF-κB pathway. These results suggest that TAB3 plays a critical role in NSCLC progression and chemoresistance and that TAB3 depletion may be a promising approach to lung cancer therapy.

Involvement of p29/SYF2/fSAP29/NTC31 in the progression of NSCLC via modulating cell proliferation

p29, also known as SYF2/fSAP29/NTC31, is a protein associated with chromatin and involved in DNA damage response, cell cycle arrest and pre-mRNA splicing. In p29-depleted cells, DNA replication was reduced and cell population in G1 phase increased. In this study, we investigated the potential role of p29 in the regulation of non-small cell lung cancer (NSCLC) progression. Western blot and immunohistochemistry staining showed that p29 was up-regulated in clinical NSCLC tissues compared with adjacent non-cancerous tissues, and the expression of p29 had a positive correlation with clinical stage and histological differentiation, as well as expression of Ki-67, a proliferating marker. Kaplan-Meier analysis indicated that patients with high level of p29 expression had poor overall survival. In addition, small interfering RNA of p29 was performed, and the effects on NSCLC growth were examined. Interference of p29 blocked S phase entry, inhibited proliferation of A549 cells and up-regulated level of p21 expression. Taken together, these results suggested that p29 might contribute to the progression of NSCLC by enhancing cell proliferation, implicating that targeting p29 might provide beneficial effects on the clinical therapy of NSCLC.

Overexpression of ADAMTS5 can regulate the migration and invasion of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the major cause of cancer-related lethality among human cancer patients globally, and the poor prognosis of this cancer is mainly explained by metastasis, so it is essential to find out the molecule mechanisms and a novel therapeutic for NSCLC. A disintegrin and metalloprotease with thrombospondin motif 5 (ADAMTS5) belongs to the protease family. It has been reported to participate in tumor migration and invasion. In this study, we showed that the expression of ADAMTS5 was higher in lung cancer tissues by Western blot. The immunohistochemistry analysis was performed in 140 NSCLC cases, and the result indicated that ADAMTS5 was significantly associated with clinical pathologic variables. The Kaplan–Meier curve showed that the high expression of ADAMTS5 was related to poor prognosis of lung cancer patients. Wound healing assays and transwell migration assays revealed that the high expression of ADAMTS5 promoted the migration and invasion of NSCLC. In a word, our findings suggest that ADAMTS5 can regulate the migration and invasion of NSCLC and it may be a useful target of therapy in NSCLC.