Stromal cell-derived factor 1 (SDF-1) and its receptor, CXCR4, play an important role in tumor progression. Epithelial-mesenchymal transition (EMT) process is linked to disease pathophysiology. This study aimed to investigate the roles and underlying mechanisms of SDF-1/CXCR4 axis in EMT process of glioblastoma. In the present study, CXCR4 activation and inhibition in U87 were induced with exogenous SDF-1 and with CXCR4 small interfering RNA (siRNA), respectively. CXCR4 downstream signal molecules AKT, ERK, and EMT biomarkers (vementin, snail, N-cadherin, and E-cadherin) were tested using the Western blot. Our results showed that SDF-1 can induce AKT and ERK phosphorylation in a dose-dependent manner, and endogenous CXCR4 can be blocked thoroughly by CXCR4 siRNA in U87. Notably SDF-1 alone treatment can induce the upregulation of vementin, snail, and N-cadherin of U87; besides, the downregulation of E-cadherin also occurred. On the contrary, CXCR4 siRNA significantly prohibited SDF-1-induced AKT and ERK phosphorylation, at the same time, EMT biomarker changes were not observed. Function analysis revealed that CXCR4 siRNA obviously interfered with U87 cell migration and proliferation, according to wound healing assay. In conclusion, this study suggested that EMT process can be triggered by the SDF-1/CXCR4 axis in glioblastoma, and then involved in the tumor cell invasion and proliferation via activation of PI3K/AKT and ERK pathway. Our study lays a new foundation for the treatment of glioblastoma through antagonizing CXCR4.
Variant pulmonary adenocarcinoma with intestinal-type molecules shares similar molecular expression with colorectal carcinoma. However, expression of such molecules and their association with survival time with clinicopathologic parameters, such as epidermal growth factor receptor (EGFR) gene status in other types of pulmonary adenocarcinoma, has been rarely demonstrated. Sixty patients with resected pulmonary adenocarcinoma were divided into the enteric differentiation group (I group, n=30) and the usual group (U group, n=30). Immunohistochemical staining was used to assess the expression of carcinoembryonic antigen (CEA), Villin, CK20, and caudal-related homeobox 2 (CDX2). EGFR gene status was examined by Fluorescence Quantitative polymerase chain reaction. Kaplan-Meier survival curve was drawn by GraphPad Prism 5.0 software. The results showed that there was a significant difference between the 2 groups (P<0.05) in the expression of Villin, CK20, and CDX2, whereas the expression of CEA showed no significant difference (P>0.05). Compared with the U group, patients in the I group were mainly female individuals and in clinical stages III to IV, prone to lymph node metastasis (P<0.05). The patients in the I group with CDX2CK20 phenotype (tumor size>5 cm) had a shorter survival time (P<0.05), and EGFR gene status was not associated with median survival time and the expression of CEA, Villin, CK20, and CDX2 (P>0.05). Thus, our research indicates that patients with enteric differentiation have unique clinical characteristics and different prognosis, which may play important roles in diagnosis and choosing therapeutic strategies for pulmonary adenocarcinoma patients in clinical practice.
Tumor immunosurveillance is known to be of critical importance in controlling tumorigenesis and progression in various cancers. The role of gamma-interferon-inducible lysosomal thiol reductase (GILT) in tumor immunosurveillance has recently been studied in several malignant diseases, but its role in breast cancer remains to be elucidated. In the present study, we found GILT as a significant different expressed gene by cDNA microarray analysis. To further determine the role of GILT in breast cancer, we examined GILT expression in breast cancers as well as noncancerous breast tissues by immunohistochemistry and real-time PCR, and assessed its association with clinicopathologic characteristics and patient outcome. The absence of GILT expression increased significantly from 2.02% (2/99) in noncancerous breast tissues to 15.6% (34/218) in breast cancer tissues (P<0.001). In accordance with its proliferation inhibiting function, GILT expression was inversely correlated with Ki67 index (P<0.05). In addition, absence of GILT was positively correlated with adverse characteristics of breast cancers, such as histological type, tumor size, lymph nodes status, and pTNM stage (P<0.05). Consistently, breast cancers with reduced GILT expression had poorer disease-free survival (P<0.005). Moreover, significantly decreased expression of GILT was found in both primary and metastatic breast cancer cells, in contrast to normal epithelial cells. These findings indicate that GILT may act as a tumor suppressor in breast cancer, in line with its previously suggested role in anti-tumor immunity. Thus, GILT has the potential to be a novel independent prognostic factor in breast cancer and further studies are needed to illustrate the underlying mechanism of this relationship.
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