BackgroundMatrix metalloproteinases (MMPs) are regarded to be relevant to the prognosis of breast cancer. Numerous studies have confirmed the association between MMPs and tumor growth, invasion and metastasis in breast cancer. However, their prognostic values for survival in patients with breast cancer remain controversial. Hence, a meta-analysis was performed to clarify a more accurate estimation of the role of MMPs on prognosis of breast cancer patients.MethodA systemic electronic search was conducted in PubMed, Embase and Web of science databases to identify eligible studies, which were associated with the relationship between MMPs and prognosis of breast cancer. The correlation in random-effect model was evaluated by using the hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsA total of 28 studies covering 4944 patients were included for meta-analysis. A summary hazard ratio (HR) of all studies was calculated, as well as the sub-group HRs. The combined HRs calculated by either univariate or multivariate analysis both suggested that overexpression of MMPs had an unfavorable impact on overall survival (OS) (HR = 1.694, 95%CI: 1.347–2.129, P < 0.001; HR = 1.611, 95%CI: 1.419–1.830, P < 0.001, respectively). And the univariate analysis showed that patients with overexpression of MMPs had worse relapse-free survival (RFS) (HR = 1.969, 95%CI: 1.460–2.655, P < 0.001) in all eligible studies. In the sub-group analyses, HRs of MMP-9 positivity with poor OS were 1.794 (95%CI: 1.330–2.420, P < 0.001) and 1.709 (95%CI: 1.157–2.526, P = 0.007) which were separately evaluated by univariate and multivariate analysis. A small number of articles demonstrated that MMP-2 overexpression was not related with shorter OS (HR = 1.400, 95%CI: 0.610–3.029, P = 0.427). Four studies included in the OS analysis of MMPs expression in serum suggested that positive expression of serum MMPs may be an unfavorable factor (HR = 1.630, 95%CI: 1.065–2.494) for breast cancer patients. No publication bias was observed in the current meta-analysis.ConclusionsOur findings suggested that MMPs overexpression (especially MMP-9, MMP-2, MMPs overexpression in serum) might indicate a higher risk of poor prognosis in breast cancer. Larger prospective studies are further needed to estimate the prognostic values of MMPs overexpression.

Background/Aims: Long noncoding RNAs (lncRNAs) contribute to the development of multiple malignant tumors. Here, we focused on the biological function and underlying molecular mechanism of an lncRNA, nuclear-enriched abundant transcript 1 (NEAT1), in lung adenocarcinoma (LUAD). Methods: In vitro experiments were conducted to determine the biological effects of NEAT1 in LUAD cells. A luciferase activity reporter assay was performed to corroborate the interaction between NEAT1 and miR-193a-3p. Data from Gene Expression Omnibus (GEO), Oncomine, The Cancer Genome Atlas (TCGA), and our in-house reverse transcription quantitative PCR (RT-qPCR) were combined to examine the expression of NEAT1 and miR-193a-3p in LUAD. To further explore the regulatory mechanism of NEAT1, we searched for putative target genes of miR-193a-3p from 12 online prediction databases and determined genes positively correlated with NEAT1 as candidate targets. Furthermore, we analyzed the expression of these selected genes using data from TCGA. Results: In vitro experiments showed that knockdown of NEAT1 in LUAD cells markedly restrained cell proliferation, invasion, and migration and stimulated cell apoptosis. The dual-luciferase reporter assay demonstrated that miR-193a-3p directly targeted NEAT1 at its 3’-UTR. We then detected NEAT1 and miR-193a-3p in LUAD cells and normal lung epithelial cells and discovered high expression of NEAT1 and low expression of miR-193a-3p in LUAD cell lines. Simultaneously, the pooled results from the GEO, Oncomine, TCGA, and in-house RT-qPCR showed that the NEAT1 expression increased while the miR-193a-3p expression decreased in LUAD tissues versus normal lung tissues. Furthermore, the USF1 gene was not only upregulated in LUAD, but also positively correlated with NEAT1, suggesting that NEAT1 may function as a ceRNA to sponge miR-193a-3p and abrogate the inhibitory effect of miR-193a-3p on USF1. Conclusions: Our findings indicate that NEAT1 plays important roles in the occurrence and progression of LUAD. It may exert its role by acting as a ceRNA to regulate miR-193a-3p.

BackgroundVimentin is a member of the intermediate filament proteins and a canonical marker of the epithelial-mesenchymal transition (EMT), which is pivotal in tumorigenesis, metastasis and invasion in non-small cell lung cancer (NSCLC). The current meta-analysis aimed to investigate the associations between vimentin and prognosis and progression in NSCLC.MethodsDatabases with literature published in English, including PubMed, Web of Science, Embase, Science Direct, Wiley Online Library, Ovid, Cochrane Central Register of Controlled Trials, LILACS and Google Scholar, and the CNKI, VIP, CBM and WanFang databases in Chinese were used for the literature search. The key terms included (1) ‘vimentin’ OR ‘vim’ OR ‘vmt’ OR ‘vm’ OR ‘hel113’ OR ‘ctrct30’ and (2) ‘pulmon*’ OR ‘lung’ OR ‘alveolar’ and (3) ‘cancer’ OR ‘carcinoma’ OR ‘tumor’ OR ‘adenocarcinoma’ OR ‘squamous’ OR ‘neoplas*’ OR ‘malignan*’. The data were combined by random effect model and the H value and I2 were used to assess the heterogeneity. All the meta-analysis was conducted using Stata 12.0.ResultsThirty-two qualified studies (4118 cases) were included in the current meta-analysis. Twelve studies with 1750 patients were included to assess the significance of vimentin in the overall survival (OS) of NSCLC; the pooled hazard ratio (HR) was 1.831 (confidence interval (CI): 1.315–2.550, P<0.001) in the univariate analysis and 1.266 (CI: 0.906–1.768, P = 0.167) in the multivariate analysis. Four studies with 988 cases were applicable to determine the significance of vimentin in the disease-free survival (DFS) of NSCLC; the pooled HR of the DFS was 1.224 (CI: 0.921–1.628, P = 0.164) in the univariate analysis and 1.254 (CI: 0.985–1.956, P = 0.067) in the multivariate analysis. Regarding the relationships between vimentin and clinicopathological factors, the pooled odds ratio (OR) with 3406 NSCLCs indicated that up-regulated vimentin was associated with smoking (OR = 1.359, CI: 1.098–1.683, P = 0.004), poor differentiation (OR = 2.133, CI: 1.664–2.735, P<0.001), an advanced TNM stage (OR = 3.275, CI: 1.987–5.397, P<0.001), vascular invasion (OR = 3.492, CI: 1.063–11.472, P = 0.039), lymph node metastasis (OR = 2.628, CI: 1.857–3.718, P<0.001), recurrence (OR = 1.631, CI: 1.052–2.528, P = 0.029) and pleural invasion (OR = 2.346, CI: 1.397–3.941, P = 0.001). There was no significant correlation between vimentin and age, gender, diameter, T stage, distant metastasis, or marginal invasion (P>0.05).ConclusionAn overexpression of vimentin may predict the progression and an unfavorable survival of NSCLC. Vimentin may represent a helpful biomarker and a potential target for the treatment strategies of NSCLC. Additional, prospective studies with large samples are necessary to confirm the significance of vimentin in NSCLC.