BackgroundECRG4 has been shown to be a candidate tumor suppressor in several tumors, but its role in glioma remains poorly understood. In this study, we examined the mRNA expression of ECRG4 and investigated its biological role in glioma cells.MethodsReal-time PCR was used to examine expression of ECRG4 in gliomas and their matched brain tissues. The effect of ECRG4 expression on cell proliferation, invasion, and migration was investigated in human U251 glioma cells. Finally, the regulation of transcription factor NF-kB by ECRG4 was evaluated by western blotting.ResultsOf the 10 paired samples analyzed, 9 glioma tissues displayed the decreased expression of ECRG4 compared to matched normal brain tissues. Cells transfected with ECRG4 showed significantly decreased cell proliferation as evaluated by MTT and colony formation assays. Furthermore, overexpression inhibited cell migration and invasion in transwell and Boyden chamber experiments and retarded the cell cycle progression from G1 to S phase by FACSCaliber cytometry. Protein levels of nuclear transcription factor NF-kB, which is involved in cell proliferation, inversely correlated with ECRG4 expression.ConclusionOur data suggest that ECRG4 serves as a tumor suppressor in glioma.

The present study examined SMAD family member 4 (Smad4), SMAD family member 2 (Smad2) and phosphorylated (p-)Smad2 expression in biopsy specimens from patients with invasive breast ductal carcinoma, in order to assess their abilities as prognostic markers. A total of 126 tissue samples were selected, and the expression of Smad2, p-Smad2 and Smad4 in carcinoma tissues was detected by immunostaining, and the association between protein expression and clinicopathological variables was analyzed. Smad4 expression was negatively correlated with human epidermal growth factor receptor 2 in carcinoma tissues, and Smad4 expression was consistent with that of p-Smad2. Although multivariate analysis revealed that Smad2, p-Smad2 and Smad4 were not independent predictors, Kaplan-Meier curves demonstrated that Smad4 positivity was correlated with a longer overall survival (OS) and progression-free survival (PFS) time. However, upon analysis of combined markers, there was a significant difference between the p-Smad2/Smad4 co-positive and co-negative patients; the latter tended to exhibit a shorter OS and PFS time, and multivariate analysis revealed that the combined expression of p-Smad2 and Smad4 may be used as an independent prognostic factor. These results suggested that the assessment of p-Smad2 and Smad4 protein expression in breast ductal carcinoma biopsy specimens may provide additional prognostic information.

Abstract. Matrix metalloproteinase-26 (MMP-26) is a novel member of the MMP family and plays a significant role in the progression of estrogen-dependent malignancies. The present study aimed to investigate the roles of MMP-26 in the growth, invasion and angiogenesis of breast cancer. pcDNA3.1(+)-neo expression plasmids carrying the proMMP-26 coding sequence were used to transfect a breast cancer cell line (MCF-7 cells). The mRNA and protein expression of MMP-26 was determined by RT-PCR, immunofluorescence analysis and flow cytometry. The morphology of transfected cells was observed under an electron microscope. An adherence and spreading assay, Boyden chamber assay, in vivo tumorigenicity assay and in vivo angiogenesis were further modeled to elucidate the roles of MMP-26 in the invasion and angiogenesis of breast cancer. Using electron microscopy, the MMP-26-transfected cells demonstrated increased atypia, including unusual mitotic figures, glucogen pools and special lysosomes in the cytoplasm. The adherence and spreading ability of MMP-26-transfected cells were increased significantly compared with cells in the control group. The Boyden chamber assay demonstrated that the migration and invasion ability of MMP-26-transfected cells was dramatically accelerated compared with the control group, but markedly reduced in the presence of anti-MMP-26 antibody. MMP-26 also increased the malignant phenotype in vivo. The number of vessel branches and the total length of vessels induced by MMP-26-transfected cells were significantly increased compared to those induced by non-transfected cells. The plasmid carrying the proMMP-26 gene was successfully transfected into breast cancer cells. Our results demonstrate that MMP-26 overexpression promotes the growth and invasion of breast cancer cells and induces angiogenesis.

Compared with other types of breast cancer, triple-negative breast cancer (TNBC) has the characteristics of rapid progression, a lack of specific molecular targets for treatment and a poor prognosis. However, based on previously published studies, TGF-β1 and survivin are potentially meaningful for the prognosis of patients with TNBC. The present study was therefore designed to measure and compare the expression of transforming growth factor-β1 (TGF-β1) and survivin in tissue samples of TNBC and non-TNBC patients in order to evaluate their ability as prognostic indicators. In total, 90 TNBC and 52 non-TNBC tissue specimens were selected, following which immunohistochemistry was used to detect the expression of TGF-β1 and survivin in the cancer tissues. Subsequently, the potential association between the expression levels of these two proteins and the clinicopathological variables was analyzed. The expression levels of TGF-β1 and survivin in TNBC tissues were found to be significantly higher compared with those in the non-TNBC tissues. In addition, the results of the present study demonstrated that TGF-β1 expression was positively associated with survivin expression in the TNBC samples, but no significant correlation was found between TGF-β1 and survivin expression in the non-TNBC samples. Kaplan-Meier (K-M) analysis was performed to assess the levels of TGF-β1 and survivin in regard to patient survival, and univariate and multivariate Cox analyses of TGF-β1 and survivin protein expression were performed to analyze the overall survival (OS) and progression-free survival (PFS) rates of patients with TNBC and non-TNBC. Although multivariate Cox analysis demonstrated that neither TGF-β1 or survivin were independent prognostic predictors of TNBC or non-TNBC, results of the K-M curve revealed that patients with TNBC with TGF-β1-and survivin-positive breast cancer exhibited shorter OS and PFS times. Multivariate Cox analysis demonstrated that in patients with TNBC, the combined expression of TGF-β1 and survivin may yield additional prognostic information, compared with patients with non-TNBC.